Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

54 files changed, 44894 insertions, 0 deletions

diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
new file mode 100644
index 000000000..c1b9f71ee
--- /dev/null
+++ b/kernel/bpf/Makefile
@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y := core.o
+ifneq ($(CONFIG_BPF_JIT_ALWAYS_ON),y)
+# ___bpf_prog_run() needs GCSE disabled on x86; see 3193c0836f203 for details
+cflags-nogcse-$(CONFIG_X86)$(CONFIG_CC_IS_GCC) := -fno-gcse
+endif
+CFLAGS_core.o += $(call cc-disable-warning, override-init) $(cflags-nogcse-yy)
+
+obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o bpf_iter.o map_iter.o task_iter.o prog_iter.o
+obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o
+obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o ringbuf.o
+obj-${CONFIG_BPF_LSM}	  += bpf_inode_storage.o
+obj-$(CONFIG_BPF_SYSCALL) += disasm.o
+obj-$(CONFIG_BPF_JIT) += trampoline.o
+obj-$(CONFIG_BPF_SYSCALL) += btf.o
+obj-$(CONFIG_BPF_JIT) += dispatcher.o
+ifeq ($(CONFIG_NET),y)
+obj-$(CONFIG_BPF_SYSCALL) += devmap.o
+obj-$(CONFIG_BPF_SYSCALL) += cpumap.o
+obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o
+obj-$(CONFIG_BPF_SYSCALL) += offload.o
+obj-$(CONFIG_BPF_SYSCALL) += net_namespace.o
+endif
+ifeq ($(CONFIG_PERF_EVENTS),y)
+obj-$(CONFIG_BPF_SYSCALL) += stackmap.o
+endif
+obj-$(CONFIG_CGROUP_BPF) += cgroup.o
+ifeq ($(CONFIG_INET),y)
+obj-$(CONFIG_BPF_SYSCALL) += reuseport_array.o
+endif
+ifeq ($(CONFIG_SYSFS),y)
+obj-$(CONFIG_DEBUG_INFO_BTF) += sysfs_btf.o
+endif
+ifeq ($(CONFIG_BPF_JIT),y)
+obj-$(CONFIG_BPF_SYSCALL) += bpf_struct_ops.o
+obj-${CONFIG_BPF_LSM} += bpf_lsm.o
+endif
+obj-$(CONFIG_BPF_PRELOAD) += preload/
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
new file mode 100644
index 000000000..f241bda26
--- /dev/null
+++ b/kernel/bpf/arraymap.c
@@ -0,0 +1,1312 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016,2017 Facebook
+ */
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/filter.h>
+#include <linux/perf_event.h>
+#include <uapi/linux/btf.h>
+#include <linux/rcupdate_trace.h>
+
+#include "map_in_map.h"
+
+#define ARRAY_CREATE_FLAG_MASK \
+	(BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \
+	 BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP)
+
+static void bpf_array_free_percpu(struct bpf_array *array)
+{
+	int i;
+
+	for (i = 0; i < array->map.max_entries; i++) {
+		free_percpu(array->pptrs[i]);
+		cond_resched();
+	}
+}
+
+static int bpf_array_alloc_percpu(struct bpf_array *array)
+{
+	void __percpu *ptr;
+	int i;
+
+	for (i = 0; i < array->map.max_entries; i++) {
+		ptr = __alloc_percpu_gfp(array->elem_size, 8,
+					 GFP_USER | __GFP_NOWARN);
+		if (!ptr) {
+			bpf_array_free_percpu(array);
+			return -ENOMEM;
+		}
+		array->pptrs[i] = ptr;
+		cond_resched();
+	}
+
+	return 0;
+}
+
+/* Called from syscall */
+int array_map_alloc_check(union bpf_attr *attr)
+{
+	bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
+	int numa_node = bpf_map_attr_numa_node(attr);
+
+	/* check sanity of attributes */
+	if (attr->max_entries == 0 || attr->key_size != 4 ||
+	    attr->value_size == 0 ||
+	    attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags) ||
+	    (percpu && numa_node != NUMA_NO_NODE))
+		return -EINVAL;
+
+	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
+	    attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP))
+		return -EINVAL;
+
+	if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY &&
+	    attr->map_flags & BPF_F_PRESERVE_ELEMS)
+		return -EINVAL;
+
+	if (attr->value_size > KMALLOC_MAX_SIZE)
+		/* if value_size is bigger, the user space won't be able to
+		 * access the elements.
+		 */
+		return -E2BIG;
+
+	return 0;
+}
+
+static struct bpf_map *array_map_alloc(union bpf_attr *attr)
+{
+	bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
+	int ret, numa_node = bpf_map_attr_numa_node(attr);
+	u32 elem_size, index_mask, max_entries;
+	bool bypass_spec_v1 = bpf_bypass_spec_v1();
+	u64 cost, array_size, mask64;
+	struct bpf_map_memory mem;
+	struct bpf_array *array;
+
+	elem_size = round_up(attr->value_size, 8);
+
+	max_entries = attr->max_entries;
+
+	/* On 32 bit archs roundup_pow_of_two() with max_entries that has
+	 * upper most bit set in u32 space is undefined behavior due to
+	 * resulting 1U << 32, so do it manually here in u64 space.
+	 */
+	mask64 = fls_long(max_entries - 1);
+	mask64 = 1ULL << mask64;
+	mask64 -= 1;
+
+	index_mask = mask64;
+	if (!bypass_spec_v1) {
+		/* round up array size to nearest power of 2,
+		 * since cpu will speculate within index_mask limits
+		 */
+		max_entries = index_mask + 1;
+		/* Check for overflows. */
+		if (max_entries < attr->max_entries)
+			return ERR_PTR(-E2BIG);
+	}
+
+	array_size = sizeof(*array);
+	if (percpu) {
+		array_size += (u64) max_entries * sizeof(void *);
+	} else {
+		/* rely on vmalloc() to return page-aligned memory and
+		 * ensure array->value is exactly page-aligned
+		 */
+		if (attr->map_flags & BPF_F_MMAPABLE) {
+			array_size = PAGE_ALIGN(array_size);
+			array_size += PAGE_ALIGN((u64) max_entries * elem_size);
+		} else {
+			array_size += (u64) max_entries * elem_size;
+		}
+	}
+
+	/* make sure there is no u32 overflow later in round_up() */
+	cost = array_size;
+	if (percpu)
+		cost += (u64)attr->max_entries * elem_size * num_possible_cpus();
+
+	ret = bpf_map_charge_init(&mem, cost);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	/* allocate all map elements and zero-initialize them */
+	if (attr->map_flags & BPF_F_MMAPABLE) {
+		void *data;
+
+		/* kmalloc'ed memory can't be mmap'ed, use explicit vmalloc */
+		data = bpf_map_area_mmapable_alloc(array_size, numa_node);
+		if (!data) {
+			bpf_map_charge_finish(&mem);
+			return ERR_PTR(-ENOMEM);
+		}
+		array = data + PAGE_ALIGN(sizeof(struct bpf_array))
+			- offsetof(struct bpf_array, value);
+	} else {
+		array = bpf_map_area_alloc(array_size, numa_node);
+	}
+	if (!array) {
+		bpf_map_charge_finish(&mem);
+		return ERR_PTR(-ENOMEM);
+	}
+	array->index_mask = index_mask;
+	array->map.bypass_spec_v1 = bypass_spec_v1;
+
+	/* copy mandatory map attributes */
+	bpf_map_init_from_attr(&array->map, attr);
+	bpf_map_charge_move(&array->map.memory, &mem);
+	array->elem_size = elem_size;
+
+	if (percpu && bpf_array_alloc_percpu(array)) {
+		bpf_map_charge_finish(&array->map.memory);
+		bpf_map_area_free(array);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return &array->map;
+}
+
+/* Called from syscall or from eBPF program */
+static void *array_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = *(u32 *)key;
+
+	if (unlikely(index >= array->map.max_entries))
+		return NULL;
+
+	return array->value + array->elem_size * (index & array->index_mask);
+}
+
+static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm,
+				       u32 off)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+
+	if (map->max_entries != 1)
+		return -ENOTSUPP;
+	if (off >= map->value_size)
+		return -EINVAL;
+
+	*imm = (unsigned long)array->value;
+	return 0;
+}
+
+static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm,
+				       u32 *off)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u64 base = (unsigned long)array->value;
+	u64 range = array->elem_size;
+
+	if (map->max_entries != 1)
+		return -ENOTSUPP;
+	if (imm < base || imm >= base + range)
+		return -ENOENT;
+
+	*off = imm - base;
+	return 0;
+}
+
+/* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
+static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	struct bpf_insn *insn = insn_buf;
+	u32 elem_size = round_up(map->value_size, 8);
+	const int ret = BPF_REG_0;
+	const int map_ptr = BPF_REG_1;
+	const int index = BPF_REG_2;
+
+	if (map->map_flags & BPF_F_INNER_MAP)
+		return -EOPNOTSUPP;
+
+	*insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
+	*insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
+	if (!map->bypass_spec_v1) {
+		*insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4);
+		*insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
+	} else {
+		*insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3);
+	}
+
+	if (is_power_of_2(elem_size)) {
+		*insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
+	} else {
+		*insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
+	}
+	*insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
+	*insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
+	*insn++ = BPF_MOV64_IMM(ret, 0);
+	return insn - insn_buf;
+}
+
+/* Called from eBPF program */
+static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = *(u32 *)key;
+
+	if (unlikely(index >= array->map.max_entries))
+		return NULL;
+
+	return this_cpu_ptr(array->pptrs[index & array->index_mask]);
+}
+
+int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = *(u32 *)key;
+	void __percpu *pptr;
+	int cpu, off = 0;
+	u32 size;
+
+	if (unlikely(index >= array->map.max_entries))
+		return -ENOENT;
+
+	/* per_cpu areas are zero-filled and bpf programs can only
+	 * access 'value_size' of them, so copying rounded areas
+	 * will not leak any kernel data
+	 */
+	size = round_up(map->value_size, 8);
+	rcu_read_lock();
+	pptr = array->pptrs[index & array->index_mask];
+	for_each_possible_cpu(cpu) {
+		bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size);
+		off += size;
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+/* Called from syscall */
+static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = key ? *(u32 *)key : U32_MAX;
+	u32 *next = (u32 *)next_key;
+
+	if (index >= array->map.max_entries) {
+		*next = 0;
+		return 0;
+	}
+
+	if (index == array->map.max_entries - 1)
+		return -ENOENT;
+
+	*next = index + 1;
+	return 0;
+}
+
+/* Called from syscall or from eBPF program */
+static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
+				 u64 map_flags)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = *(u32 *)key;
+	char *val;
+
+	if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST))
+		/* unknown flags */
+		return -EINVAL;
+
+	if (unlikely(index >= array->map.max_entries))
+		/* all elements were pre-allocated, cannot insert a new one */
+		return -E2BIG;
+
+	if (unlikely(map_flags & BPF_NOEXIST))
+		/* all elements already exist */
+		return -EEXIST;
+
+	if (unlikely((map_flags & BPF_F_LOCK) &&
+		     !map_value_has_spin_lock(map)))
+		return -EINVAL;
+
+	if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		memcpy(this_cpu_ptr(array->pptrs[index & array->index_mask]),
+		       value, map->value_size);
+	} else {
+		val = array->value +
+			array->elem_size * (index & array->index_mask);
+		if (map_flags & BPF_F_LOCK)
+			copy_map_value_locked(map, val, value, false);
+		else
+			copy_map_value(map, val, value);
+	}
+	return 0;
+}
+
+int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
+			    u64 map_flags)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = *(u32 *)key;
+	void __percpu *pptr;
+	int cpu, off = 0;
+	u32 size;
+
+	if (unlikely(map_flags > BPF_EXIST))
+		/* unknown flags */
+		return -EINVAL;
+
+	if (unlikely(index >= array->map.max_entries))
+		/* all elements were pre-allocated, cannot insert a new one */
+		return -E2BIG;
+
+	if (unlikely(map_flags == BPF_NOEXIST))
+		/* all elements already exist */
+		return -EEXIST;
+
+	/* the user space will provide round_up(value_size, 8) bytes that
+	 * will be copied into per-cpu area. bpf programs can only access
+	 * value_size of it. During lookup the same extra bytes will be
+	 * returned or zeros which were zero-filled by percpu_alloc,
+	 * so no kernel data leaks possible
+	 */
+	size = round_up(map->value_size, 8);
+	rcu_read_lock();
+	pptr = array->pptrs[index & array->index_mask];
+	for_each_possible_cpu(cpu) {
+		bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size);
+		off += size;
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+/* Called from syscall or from eBPF program */
+static int array_map_delete_elem(struct bpf_map *map, void *key)
+{
+	return -EINVAL;
+}
+
+static void *array_map_vmalloc_addr(struct bpf_array *array)
+{
+	return (void *)round_down((unsigned long)array, PAGE_SIZE);
+}
+
+/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
+static void array_map_free(struct bpf_map *map)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+
+	if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+		bpf_array_free_percpu(array);
+
+	if (array->map.map_flags & BPF_F_MMAPABLE)
+		bpf_map_area_free(array_map_vmalloc_addr(array));
+	else
+		bpf_map_area_free(array);
+}
+
+static void array_map_seq_show_elem(struct bpf_map *map, void *key,
+				    struct seq_file *m)
+{
+	void *value;
+
+	rcu_read_lock();
+
+	value = array_map_lookup_elem(map, key);
+	if (!value) {
+		rcu_read_unlock();
+		return;
+	}
+
+	if (map->btf_key_type_id)
+		seq_printf(m, "%u: ", *(u32 *)key);
+	btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
+	seq_puts(m, "\n");
+
+	rcu_read_unlock();
+}
+
+static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key,
+					   struct seq_file *m)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 index = *(u32 *)key;
+	void __percpu *pptr;
+	int cpu;
+
+	rcu_read_lock();
+
+	seq_printf(m, "%u: {\n", *(u32 *)key);
+	pptr = array->pptrs[index & array->index_mask];
+	for_each_possible_cpu(cpu) {
+		seq_printf(m, "\tcpu%d: ", cpu);
+		btf_type_seq_show(map->btf, map->btf_value_type_id,
+				  per_cpu_ptr(pptr, cpu), m);
+		seq_puts(m, "\n");
+	}
+	seq_puts(m, "}\n");
+
+	rcu_read_unlock();
+}
+
+static int array_map_check_btf(const struct bpf_map *map,
+			       const struct btf *btf,
+			       const struct btf_type *key_type,
+			       const struct btf_type *value_type)
+{
+	u32 int_data;
+
+	/* One exception for keyless BTF: .bss/.data/.rodata map */
+	if (btf_type_is_void(key_type)) {
+		if (map->map_type != BPF_MAP_TYPE_ARRAY ||
+		    map->max_entries != 1)
+			return -EINVAL;
+
+		if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC)
+			return -EINVAL;
+
+		return 0;
+	}
+
+	if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
+		return -EINVAL;
+
+	int_data = *(u32 *)(key_type + 1);
+	/* bpf array can only take a u32 key. This check makes sure
+	 * that the btf matches the attr used during map_create.
+	 */
+	if (BTF_INT_BITS(int_data) != 32 || BTF_INT_OFFSET(int_data))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT;
+
+	if (!(map->map_flags & BPF_F_MMAPABLE))
+		return -EINVAL;
+
+	if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) >
+	    PAGE_ALIGN((u64)array->map.max_entries * array->elem_size))
+		return -EINVAL;
+
+	return remap_vmalloc_range(vma, array_map_vmalloc_addr(array),
+				   vma->vm_pgoff + pgoff);
+}
+
+static bool array_map_meta_equal(const struct bpf_map *meta0,
+				 const struct bpf_map *meta1)
+{
+	if (!bpf_map_meta_equal(meta0, meta1))
+		return false;
+	return meta0->map_flags & BPF_F_INNER_MAP ? true :
+	       meta0->max_entries == meta1->max_entries;
+}
+
+struct bpf_iter_seq_array_map_info {
+	struct bpf_map *map;
+	void *percpu_value_buf;
+	u32 index;
+};
+
+static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_array_map_info *info = seq->private;
+	struct bpf_map *map = info->map;
+	struct bpf_array *array;
+	u32 index;
+
+	if (info->index >= map->max_entries)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	array = container_of(map, struct bpf_array, map);
+	index = info->index & array->index_mask;
+	if (info->percpu_value_buf)
+	       return array->pptrs[index];
+	return array->value + array->elem_size * index;
+}
+
+static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_array_map_info *info = seq->private;
+	struct bpf_map *map = info->map;
+	struct bpf_array *array;
+	u32 index;
+
+	++*pos;
+	++info->index;
+	if (info->index >= map->max_entries)
+		return NULL;
+
+	array = container_of(map, struct bpf_array, map);
+	index = info->index & array->index_mask;
+	if (info->percpu_value_buf)
+	       return array->pptrs[index];
+	return array->value + array->elem_size * index;
+}
+
+static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
+{
+	struct bpf_iter_seq_array_map_info *info = seq->private;
+	struct bpf_iter__bpf_map_elem ctx = {};
+	struct bpf_map *map = info->map;
+	struct bpf_iter_meta meta;
+	struct bpf_prog *prog;
+	int off = 0, cpu = 0;
+	void __percpu **pptr;
+	u32 size;
+
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, v == NULL);
+	if (!prog)
+		return 0;
+
+	ctx.meta = &meta;
+	ctx.map = info->map;
+	if (v) {
+		ctx.key = &info->index;
+
+		if (!info->percpu_value_buf) {
+			ctx.value = v;
+		} else {
+			pptr = v;
+			size = round_up(map->value_size, 8);
+			for_each_possible_cpu(cpu) {
+				bpf_long_memcpy(info->percpu_value_buf + off,
+						per_cpu_ptr(pptr, cpu),
+						size);
+				off += size;
+			}
+			ctx.value = info->percpu_value_buf;
+		}
+	}
+
+	return bpf_iter_run_prog(prog, &ctx);
+}
+
+static int bpf_array_map_seq_show(struct seq_file *seq, void *v)
+{
+	return __bpf_array_map_seq_show(seq, v);
+}
+
+static void bpf_array_map_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__bpf_array_map_seq_show(seq, NULL);
+}
+
+static int bpf_iter_init_array_map(void *priv_data,
+				   struct bpf_iter_aux_info *aux)
+{
+	struct bpf_iter_seq_array_map_info *seq_info = priv_data;
+	struct bpf_map *map = aux->map;
+	void *value_buf;
+	u32 buf_size;
+
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		buf_size = round_up(map->value_size, 8) * num_possible_cpus();
+		value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
+		if (!value_buf)
+			return -ENOMEM;
+
+		seq_info->percpu_value_buf = value_buf;
+	}
+
+	/* bpf_iter_attach_map() acquires a map uref, and the uref may be
+	 * released before or in the middle of iterating map elements, so
+	 * acquire an extra map uref for iterator.
+	 */
+	bpf_map_inc_with_uref(map);
+	seq_info->map = map;
+	return 0;
+}
+
+static void bpf_iter_fini_array_map(void *priv_data)
+{
+	struct bpf_iter_seq_array_map_info *seq_info = priv_data;
+
+	bpf_map_put_with_uref(seq_info->map);
+	kfree(seq_info->percpu_value_buf);
+}
+
+static const struct seq_operations bpf_array_map_seq_ops = {
+	.start	= bpf_array_map_seq_start,
+	.next	= bpf_array_map_seq_next,
+	.stop	= bpf_array_map_seq_stop,
+	.show	= bpf_array_map_seq_show,
+};
+
+static const struct bpf_iter_seq_info iter_seq_info = {
+	.seq_ops		= &bpf_array_map_seq_ops,
+	.init_seq_private	= bpf_iter_init_array_map,
+	.fini_seq_private	= bpf_iter_fini_array_map,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_array_map_info),
+};
+
+static int array_map_btf_id;
+const struct bpf_map_ops array_map_ops = {
+	.map_meta_equal = array_map_meta_equal,
+	.map_alloc_check = array_map_alloc_check,
+	.map_alloc = array_map_alloc,
+	.map_free = array_map_free,
+	.map_get_next_key = array_map_get_next_key,
+	.map_lookup_elem = array_map_lookup_elem,
+	.map_update_elem = array_map_update_elem,
+	.map_delete_elem = array_map_delete_elem,
+	.map_gen_lookup = array_map_gen_lookup,
+	.map_direct_value_addr = array_map_direct_value_addr,
+	.map_direct_value_meta = array_map_direct_value_meta,
+	.map_mmap = array_map_mmap,
+	.map_seq_show_elem = array_map_seq_show_elem,
+	.map_check_btf = array_map_check_btf,
+	.map_lookup_batch = generic_map_lookup_batch,
+	.map_update_batch = generic_map_update_batch,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &array_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
+};
+
+static int percpu_array_map_btf_id;
+const struct bpf_map_ops percpu_array_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = array_map_alloc_check,
+	.map_alloc = array_map_alloc,
+	.map_free = array_map_free,
+	.map_get_next_key = array_map_get_next_key,
+	.map_lookup_elem = percpu_array_map_lookup_elem,
+	.map_update_elem = array_map_update_elem,
+	.map_delete_elem = array_map_delete_elem,
+	.map_seq_show_elem = percpu_array_map_seq_show_elem,
+	.map_check_btf = array_map_check_btf,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &percpu_array_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
+};
+
+static int fd_array_map_alloc_check(union bpf_attr *attr)
+{
+	/* only file descriptors can be stored in this type of map */
+	if (attr->value_size != sizeof(u32))
+		return -EINVAL;
+	/* Program read-only/write-only not supported for special maps yet. */
+	if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG))
+		return -EINVAL;
+	return array_map_alloc_check(attr);
+}
+
+static void fd_array_map_free(struct bpf_map *map)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	int i;
+
+	/* make sure it's empty */
+	for (i = 0; i < array->map.max_entries; i++)
+		BUG_ON(array->ptrs[i] != NULL);
+
+	bpf_map_area_free(array);
+}
+
+static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+/* only called from syscall */
+int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
+{
+	void **elem, *ptr;
+	int ret =  0;
+
+	if (!map->ops->map_fd_sys_lookup_elem)
+		return -ENOTSUPP;
+
+	rcu_read_lock();
+	elem = array_map_lookup_elem(map, key);
+	if (elem && (ptr = READ_ONCE(*elem)))
+		*value = map->ops->map_fd_sys_lookup_elem(ptr);
+	else
+		ret = -ENOENT;
+	rcu_read_unlock();
+
+	return ret;
+}
+
+/* only called from syscall */
+int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
+				 void *key, void *value, u64 map_flags)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	void *new_ptr, *old_ptr;
+	u32 index = *(u32 *)key, ufd;
+
+	if (map_flags != BPF_ANY)
+		return -EINVAL;
+
+	if (index >= array->map.max_entries)
+		return -E2BIG;
+
+	ufd = *(u32 *)value;
+	new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
+	if (IS_ERR(new_ptr))
+		return PTR_ERR(new_ptr);
+
+	if (map->ops->map_poke_run) {
+		mutex_lock(&array->aux->poke_mutex);
+		old_ptr = xchg(array->ptrs + index, new_ptr);
+		map->ops->map_poke_run(map, index, old_ptr, new_ptr);
+		mutex_unlock(&array->aux->poke_mutex);
+	} else {
+		old_ptr = xchg(array->ptrs + index, new_ptr);
+	}
+
+	if (old_ptr)
+		map->ops->map_fd_put_ptr(old_ptr);
+	return 0;
+}
+
+static int fd_array_map_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	void *old_ptr;
+	u32 index = *(u32 *)key;
+
+	if (index >= array->map.max_entries)
+		return -E2BIG;
+
+	if (map->ops->map_poke_run) {
+		mutex_lock(&array->aux->poke_mutex);
+		old_ptr = xchg(array->ptrs + index, NULL);
+		map->ops->map_poke_run(map, index, old_ptr, NULL);
+		mutex_unlock(&array->aux->poke_mutex);
+	} else {
+		old_ptr = xchg(array->ptrs + index, NULL);
+	}
+
+	if (old_ptr) {
+		map->ops->map_fd_put_ptr(old_ptr);
+		return 0;
+	} else {
+		return -ENOENT;
+	}
+}
+
+static void *prog_fd_array_get_ptr(struct bpf_map *map,
+				   struct file *map_file, int fd)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	struct bpf_prog *prog = bpf_prog_get(fd);
+
+	if (IS_ERR(prog))
+		return prog;
+
+	if (!bpf_prog_array_compatible(array, prog)) {
+		bpf_prog_put(prog);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return prog;
+}
+
+static void prog_fd_array_put_ptr(void *ptr)
+{
+	bpf_prog_put(ptr);
+}
+
+static u32 prog_fd_array_sys_lookup_elem(void *ptr)
+{
+	return ((struct bpf_prog *)ptr)->aux->id;
+}
+
+/* decrement refcnt of all bpf_progs that are stored in this map */
+static void bpf_fd_array_map_clear(struct bpf_map *map)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	int i;
+
+	for (i = 0; i < array->map.max_entries; i++)
+		fd_array_map_delete_elem(map, &i);
+}
+
+static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key,
+					 struct seq_file *m)
+{
+	void **elem, *ptr;
+	u32 prog_id;
+
+	rcu_read_lock();
+
+	elem = array_map_lookup_elem(map, key);
+	if (elem) {
+		ptr = READ_ONCE(*elem);
+		if (ptr) {
+			seq_printf(m, "%u: ", *(u32 *)key);
+			prog_id = prog_fd_array_sys_lookup_elem(ptr);
+			btf_type_seq_show(map->btf, map->btf_value_type_id,
+					  &prog_id, m);
+			seq_puts(m, "\n");
+		}
+	}
+
+	rcu_read_unlock();
+}
+
+struct prog_poke_elem {
+	struct list_head list;
+	struct bpf_prog_aux *aux;
+};
+
+static int prog_array_map_poke_track(struct bpf_map *map,
+				     struct bpf_prog_aux *prog_aux)
+{
+	struct prog_poke_elem *elem;
+	struct bpf_array_aux *aux;
+	int ret = 0;
+
+	aux = container_of(map, struct bpf_array, map)->aux;
+	mutex_lock(&aux->poke_mutex);
+	list_for_each_entry(elem, &aux->poke_progs, list) {
+		if (elem->aux == prog_aux)
+			goto out;
+	}
+
+	elem = kmalloc(sizeof(*elem), GFP_KERNEL);
+	if (!elem) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	INIT_LIST_HEAD(&elem->list);
+	/* We must track the program's aux info at this point in time
+	 * since the program pointer itself may not be stable yet, see
+	 * also comment in prog_array_map_poke_run().
+	 */
+	elem->aux = prog_aux;
+
+	list_add_tail(&elem->list, &aux->poke_progs);
+out:
+	mutex_unlock(&aux->poke_mutex);
+	return ret;
+}
+
+static void prog_array_map_poke_untrack(struct bpf_map *map,
+					struct bpf_prog_aux *prog_aux)
+{
+	struct prog_poke_elem *elem, *tmp;
+	struct bpf_array_aux *aux;
+
+	aux = container_of(map, struct bpf_array, map)->aux;
+	mutex_lock(&aux->poke_mutex);
+	list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
+		if (elem->aux == prog_aux) {
+			list_del_init(&elem->list);
+			kfree(elem);
+			break;
+		}
+	}
+	mutex_unlock(&aux->poke_mutex);
+}
+
+static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
+				    struct bpf_prog *old,
+				    struct bpf_prog *new)
+{
+	u8 *old_addr, *new_addr, *old_bypass_addr;
+	struct prog_poke_elem *elem;
+	struct bpf_array_aux *aux;
+
+	aux = container_of(map, struct bpf_array, map)->aux;
+	WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex));
+
+	list_for_each_entry(elem, &aux->poke_progs, list) {
+		struct bpf_jit_poke_descriptor *poke;
+		int i, ret;
+
+		for (i = 0; i < elem->aux->size_poke_tab; i++) {
+			poke = &elem->aux->poke_tab[i];
+
+			/* Few things to be aware of:
+			 *
+			 * 1) We can only ever access aux in this context, but
+			 *    not aux->prog since it might not be stable yet and
+			 *    there could be danger of use after free otherwise.
+			 * 2) Initially when we start tracking aux, the program
+			 *    is not JITed yet and also does not have a kallsyms
+			 *    entry. We skip these as poke->tailcall_target_stable
+			 *    is not active yet. The JIT will do the final fixup
+			 *    before setting it stable. The various
+			 *    poke->tailcall_target_stable are successively
+			 *    activated, so tail call updates can arrive from here
+			 *    while JIT is still finishing its final fixup for
+			 *    non-activated poke entries.
+			 * 3) On program teardown, the program's kallsym entry gets
+			 *    removed out of RCU callback, but we can only untrack
+			 *    from sleepable context, therefore bpf_arch_text_poke()
+			 *    might not see that this is in BPF text section and
+			 *    bails out with -EINVAL. As these are unreachable since
+			 *    RCU grace period already passed, we simply skip them.
+			 * 4) Also programs reaching refcount of zero while patching
+			 *    is in progress is okay since we're protected under
+			 *    poke_mutex and untrack the programs before the JIT
+			 *    buffer is freed. When we're still in the middle of
+			 *    patching and suddenly kallsyms entry of the program
+			 *    gets evicted, we just skip the rest which is fine due
+			 *    to point 3).
+			 * 5) Any other error happening below from bpf_arch_text_poke()
+			 *    is a unexpected bug.
+			 */
+			if (!READ_ONCE(poke->tailcall_target_stable))
+				continue;
+			if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
+				continue;
+			if (poke->tail_call.map != map ||
+			    poke->tail_call.key != key)
+				continue;
+
+			old_bypass_addr = old ? NULL : poke->bypass_addr;
+			old_addr = old ? (u8 *)old->bpf_func + poke->adj_off : NULL;
+			new_addr = new ? (u8 *)new->bpf_func + poke->adj_off : NULL;
+
+			if (new) {
+				ret = bpf_arch_text_poke(poke->tailcall_target,
+							 BPF_MOD_JUMP,
+							 old_addr, new_addr);
+				BUG_ON(ret < 0 && ret != -EINVAL);
+				if (!old) {
+					ret = bpf_arch_text_poke(poke->tailcall_bypass,
+								 BPF_MOD_JUMP,
+								 poke->bypass_addr,
+								 NULL);
+					BUG_ON(ret < 0 && ret != -EINVAL);
+				}
+			} else {
+				ret = bpf_arch_text_poke(poke->tailcall_bypass,
+							 BPF_MOD_JUMP,
+							 old_bypass_addr,
+							 poke->bypass_addr);
+				BUG_ON(ret < 0 && ret != -EINVAL);
+				/* let other CPUs finish the execution of program
+				 * so that it will not possible to expose them
+				 * to invalid nop, stack unwind, nop state
+				 */
+				if (!ret)
+					synchronize_rcu();
+				ret = bpf_arch_text_poke(poke->tailcall_target,
+							 BPF_MOD_JUMP,
+							 old_addr, NULL);
+				BUG_ON(ret < 0 && ret != -EINVAL);
+			}
+		}
+	}
+}
+
+static void prog_array_map_clear_deferred(struct work_struct *work)
+{
+	struct bpf_map *map = container_of(work, struct bpf_array_aux,
+					   work)->map;
+	bpf_fd_array_map_clear(map);
+	bpf_map_put(map);
+}
+
+static void prog_array_map_clear(struct bpf_map *map)
+{
+	struct bpf_array_aux *aux = container_of(map, struct bpf_array,
+						 map)->aux;
+	bpf_map_inc(map);
+	schedule_work(&aux->work);
+}
+
+static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_array_aux *aux;
+	struct bpf_map *map;
+
+	aux = kzalloc(sizeof(*aux), GFP_KERNEL);
+	if (!aux)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_WORK(&aux->work, prog_array_map_clear_deferred);
+	INIT_LIST_HEAD(&aux->poke_progs);
+	mutex_init(&aux->poke_mutex);
+	spin_lock_init(&aux->owner.lock);
+
+	map = array_map_alloc(attr);
+	if (IS_ERR(map)) {
+		kfree(aux);
+		return map;
+	}
+
+	container_of(map, struct bpf_array, map)->aux = aux;
+	aux->map = map;
+
+	return map;
+}
+
+static void prog_array_map_free(struct bpf_map *map)
+{
+	struct prog_poke_elem *elem, *tmp;
+	struct bpf_array_aux *aux;
+
+	aux = container_of(map, struct bpf_array, map)->aux;
+	list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
+		list_del_init(&elem->list);
+		kfree(elem);
+	}
+	kfree(aux);
+	fd_array_map_free(map);
+}
+
+/* prog_array->aux->{type,jited} is a runtime binding.
+ * Doing static check alone in the verifier is not enough.
+ * Thus, prog_array_map cannot be used as an inner_map
+ * and map_meta_equal is not implemented.
+ */
+static int prog_array_map_btf_id;
+const struct bpf_map_ops prog_array_map_ops = {
+	.map_alloc_check = fd_array_map_alloc_check,
+	.map_alloc = prog_array_map_alloc,
+	.map_free = prog_array_map_free,
+	.map_poke_track = prog_array_map_poke_track,
+	.map_poke_untrack = prog_array_map_poke_untrack,
+	.map_poke_run = prog_array_map_poke_run,
+	.map_get_next_key = array_map_get_next_key,
+	.map_lookup_elem = fd_array_map_lookup_elem,
+	.map_delete_elem = fd_array_map_delete_elem,
+	.map_fd_get_ptr = prog_fd_array_get_ptr,
+	.map_fd_put_ptr = prog_fd_array_put_ptr,
+	.map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,
+	.map_release_uref = prog_array_map_clear,
+	.map_seq_show_elem = prog_array_map_seq_show_elem,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &prog_array_map_btf_id,
+};
+
+static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
+						   struct file *map_file)
+{
+	struct bpf_event_entry *ee;
+
+	ee = kzalloc(sizeof(*ee), GFP_ATOMIC);
+	if (ee) {
+		ee->event = perf_file->private_data;
+		ee->perf_file = perf_file;
+		ee->map_file = map_file;
+	}
+
+	return ee;
+}
+
+static void __bpf_event_entry_free(struct rcu_head *rcu)
+{
+	struct bpf_event_entry *ee;
+
+	ee = container_of(rcu, struct bpf_event_entry, rcu);
+	fput(ee->perf_file);
+	kfree(ee);
+}
+
+static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee)
+{
+	call_rcu(&ee->rcu, __bpf_event_entry_free);
+}
+
+static void *perf_event_fd_array_get_ptr(struct bpf_map *map,
+					 struct file *map_file, int fd)
+{
+	struct bpf_event_entry *ee;
+	struct perf_event *event;
+	struct file *perf_file;
+	u64 value;
+
+	perf_file = perf_event_get(fd);
+	if (IS_ERR(perf_file))
+		return perf_file;
+
+	ee = ERR_PTR(-EOPNOTSUPP);
+	event = perf_file->private_data;
+	if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP)
+		goto err_out;
+
+	ee = bpf_event_entry_gen(perf_file, map_file);
+	if (ee)
+		return ee;
+	ee = ERR_PTR(-ENOMEM);
+err_out:
+	fput(perf_file);
+	return ee;
+}
+
+static void perf_event_fd_array_put_ptr(void *ptr)
+{
+	bpf_event_entry_free_rcu(ptr);
+}
+
+static void perf_event_fd_array_release(struct bpf_map *map,
+					struct file *map_file)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	struct bpf_event_entry *ee;
+	int i;
+
+	if (map->map_flags & BPF_F_PRESERVE_ELEMS)
+		return;
+
+	rcu_read_lock();
+	for (i = 0; i < array->map.max_entries; i++) {
+		ee = READ_ONCE(array->ptrs[i]);
+		if (ee && ee->map_file == map_file)
+			fd_array_map_delete_elem(map, &i);
+	}
+	rcu_read_unlock();
+}
+
+static void perf_event_fd_array_map_free(struct bpf_map *map)
+{
+	if (map->map_flags & BPF_F_PRESERVE_ELEMS)
+		bpf_fd_array_map_clear(map);
+	fd_array_map_free(map);
+}
+
+static int perf_event_array_map_btf_id;
+const struct bpf_map_ops perf_event_array_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = fd_array_map_alloc_check,
+	.map_alloc = array_map_alloc,
+	.map_free = perf_event_fd_array_map_free,
+	.map_get_next_key = array_map_get_next_key,
+	.map_lookup_elem = fd_array_map_lookup_elem,
+	.map_delete_elem = fd_array_map_delete_elem,
+	.map_fd_get_ptr = perf_event_fd_array_get_ptr,
+	.map_fd_put_ptr = perf_event_fd_array_put_ptr,
+	.map_release = perf_event_fd_array_release,
+	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &perf_event_array_map_btf_id,
+};
+
+#ifdef CONFIG_CGROUPS
+static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
+				     struct file *map_file /* not used */,
+				     int fd)
+{
+	return cgroup_get_from_fd(fd);
+}
+
+static void cgroup_fd_array_put_ptr(void *ptr)
+{
+	/* cgroup_put free cgrp after a rcu grace period */
+	cgroup_put(ptr);
+}
+
+static void cgroup_fd_array_free(struct bpf_map *map)
+{
+	bpf_fd_array_map_clear(map);
+	fd_array_map_free(map);
+}
+
+static int cgroup_array_map_btf_id;
+const struct bpf_map_ops cgroup_array_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = fd_array_map_alloc_check,
+	.map_alloc = array_map_alloc,
+	.map_free = cgroup_fd_array_free,
+	.map_get_next_key = array_map_get_next_key,
+	.map_lookup_elem = fd_array_map_lookup_elem,
+	.map_delete_elem = fd_array_map_delete_elem,
+	.map_fd_get_ptr = cgroup_fd_array_get_ptr,
+	.map_fd_put_ptr = cgroup_fd_array_put_ptr,
+	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &cgroup_array_map_btf_id,
+};
+#endif
+
+static struct bpf_map *array_of_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_map *map, *inner_map_meta;
+
+	inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
+	if (IS_ERR(inner_map_meta))
+		return inner_map_meta;
+
+	map = array_map_alloc(attr);
+	if (IS_ERR(map)) {
+		bpf_map_meta_free(inner_map_meta);
+		return map;
+	}
+
+	map->inner_map_meta = inner_map_meta;
+
+	return map;
+}
+
+static void array_of_map_free(struct bpf_map *map)
+{
+	/* map->inner_map_meta is only accessed by syscall which
+	 * is protected by fdget/fdput.
+	 */
+	bpf_map_meta_free(map->inner_map_meta);
+	bpf_fd_array_map_clear(map);
+	fd_array_map_free(map);
+}
+
+static void *array_of_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_map **inner_map = array_map_lookup_elem(map, key);
+
+	if (!inner_map)
+		return NULL;
+
+	return READ_ONCE(*inner_map);
+}
+
+static int array_of_map_gen_lookup(struct bpf_map *map,
+				   struct bpf_insn *insn_buf)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u32 elem_size = round_up(map->value_size, 8);
+	struct bpf_insn *insn = insn_buf;
+	const int ret = BPF_REG_0;
+	const int map_ptr = BPF_REG_1;
+	const int index = BPF_REG_2;
+
+	*insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
+	*insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
+	if (!map->bypass_spec_v1) {
+		*insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6);
+		*insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
+	} else {
+		*insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5);
+	}
+	if (is_power_of_2(elem_size))
+		*insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
+	else
+		*insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
+	*insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
+	*insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
+	*insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
+	*insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
+	*insn++ = BPF_MOV64_IMM(ret, 0);
+
+	return insn - insn_buf;
+}
+
+static int array_of_maps_map_btf_id;
+const struct bpf_map_ops array_of_maps_map_ops = {
+	.map_alloc_check = fd_array_map_alloc_check,
+	.map_alloc = array_of_map_alloc,
+	.map_free = array_of_map_free,
+	.map_get_next_key = array_map_get_next_key,
+	.map_lookup_elem = array_of_map_lookup_elem,
+	.map_delete_elem = fd_array_map_delete_elem,
+	.map_fd_get_ptr = bpf_map_fd_get_ptr,
+	.map_fd_put_ptr = bpf_map_fd_put_ptr,
+	.map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
+	.map_gen_lookup = array_of_map_gen_lookup,
+	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_array",
+	.map_btf_id = &array_of_maps_map_btf_id,
+};
diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c
new file mode 100644
index 000000000..a4ac48c7d
--- /dev/null
+++ b/kernel/bpf/bpf_inode_storage.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Facebook
+ * Copyright 2020 Google LLC.
+ */
+
+#include <linux/rculist.h>
+#include <linux/list.h>
+#include <linux/hash.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/bpf.h>
+#include <linux/bpf_local_storage.h>
+#include <net/sock.h>
+#include <uapi/linux/sock_diag.h>
+#include <uapi/linux/btf.h>
+#include <linux/bpf_lsm.h>
+#include <linux/btf_ids.h>
+#include <linux/fdtable.h>
+
+DEFINE_BPF_STORAGE_CACHE(inode_cache);
+
+static struct bpf_local_storage __rcu **
+inode_storage_ptr(void *owner)
+{
+	struct inode *inode = owner;
+	struct bpf_storage_blob *bsb;
+
+	bsb = bpf_inode(inode);
+	if (!bsb)
+		return NULL;
+	return &bsb->storage;
+}
+
+static struct bpf_local_storage_data *inode_storage_lookup(struct inode *inode,
+							   struct bpf_map *map,
+							   bool cacheit_lockit)
+{
+	struct bpf_local_storage *inode_storage;
+	struct bpf_local_storage_map *smap;
+	struct bpf_storage_blob *bsb;
+
+	bsb = bpf_inode(inode);
+	if (!bsb)
+		return NULL;
+
+	inode_storage = rcu_dereference(bsb->storage);
+	if (!inode_storage)
+		return NULL;
+
+	smap = (struct bpf_local_storage_map *)map;
+	return bpf_local_storage_lookup(inode_storage, smap, cacheit_lockit);
+}
+
+void bpf_inode_storage_free(struct inode *inode)
+{
+	struct bpf_local_storage_elem *selem;
+	struct bpf_local_storage *local_storage;
+	bool free_inode_storage = false;
+	struct bpf_storage_blob *bsb;
+	struct hlist_node *n;
+
+	bsb = bpf_inode(inode);
+	if (!bsb)
+		return;
+
+	rcu_read_lock();
+
+	local_storage = rcu_dereference(bsb->storage);
+	if (!local_storage) {
+		rcu_read_unlock();
+		return;
+	}
+
+	/* Netiher the bpf_prog nor the bpf-map's syscall
+	 * could be modifying the local_storage->list now.
+	 * Thus, no elem can be added-to or deleted-from the
+	 * local_storage->list by the bpf_prog or by the bpf-map's syscall.
+	 *
+	 * It is racing with bpf_local_storage_map_free() alone
+	 * when unlinking elem from the local_storage->list and
+	 * the map's bucket->list.
+	 */
+	raw_spin_lock_bh(&local_storage->lock);
+	hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) {
+		/* Always unlink from map before unlinking from
+		 * local_storage.
+		 */
+		bpf_selem_unlink_map(selem);
+		free_inode_storage = bpf_selem_unlink_storage_nolock(
+			local_storage, selem, false);
+	}
+	raw_spin_unlock_bh(&local_storage->lock);
+	rcu_read_unlock();
+
+	/* free_inoode_storage should always be true as long as
+	 * local_storage->list was non-empty.
+	 */
+	if (free_inode_storage)
+		kfree_rcu(local_storage, rcu);
+}
+
+static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_local_storage_data *sdata;
+	struct file *f;
+	int fd;
+
+	fd = *(int *)key;
+	f = fget_raw(fd);
+	if (!f)
+		return ERR_PTR(-EBADF);
+
+	sdata = inode_storage_lookup(f->f_inode, map, true);
+	fput(f);
+	return sdata ? sdata->data : NULL;
+}
+
+static int bpf_fd_inode_storage_update_elem(struct bpf_map *map, void *key,
+					 void *value, u64 map_flags)
+{
+	struct bpf_local_storage_data *sdata;
+	struct file *f;
+	int fd;
+
+	fd = *(int *)key;
+	f = fget_raw(fd);
+	if (!f)
+		return -EBADF;
+	if (!inode_storage_ptr(f->f_inode)) {
+		fput(f);
+		return -EBADF;
+	}
+
+	sdata = bpf_local_storage_update(f->f_inode,
+					 (struct bpf_local_storage_map *)map,
+					 value, map_flags);
+	fput(f);
+	return PTR_ERR_OR_ZERO(sdata);
+}
+
+static int inode_storage_delete(struct inode *inode, struct bpf_map *map)
+{
+	struct bpf_local_storage_data *sdata;
+
+	sdata = inode_storage_lookup(inode, map, false);
+	if (!sdata)
+		return -ENOENT;
+
+	bpf_selem_unlink(SELEM(sdata));
+
+	return 0;
+}
+
+static int bpf_fd_inode_storage_delete_elem(struct bpf_map *map, void *key)
+{
+	struct file *f;
+	int fd, err;
+
+	fd = *(int *)key;
+	f = fget_raw(fd);
+	if (!f)
+		return -EBADF;
+
+	err = inode_storage_delete(f->f_inode, map);
+	fput(f);
+	return err;
+}
+
+BPF_CALL_4(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode,
+	   void *, value, u64, flags)
+{
+	struct bpf_local_storage_data *sdata;
+
+	if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE))
+		return (unsigned long)NULL;
+
+	/* explicitly check that the inode_storage_ptr is not
+	 * NULL as inode_storage_lookup returns NULL in this case and
+	 * bpf_local_storage_update expects the owner to have a
+	 * valid storage pointer.
+	 */
+	if (!inode || !inode_storage_ptr(inode))
+		return (unsigned long)NULL;
+
+	sdata = inode_storage_lookup(inode, map, true);
+	if (sdata)
+		return (unsigned long)sdata->data;
+
+	/* This helper must only called from where the inode is gurranteed
+	 * to have a refcount and cannot be freed.
+	 */
+	if (flags & BPF_LOCAL_STORAGE_GET_F_CREATE) {
+		sdata = bpf_local_storage_update(
+			inode, (struct bpf_local_storage_map *)map, value,
+			BPF_NOEXIST);
+		return IS_ERR(sdata) ? (unsigned long)NULL :
+					     (unsigned long)sdata->data;
+	}
+
+	return (unsigned long)NULL;
+}
+
+BPF_CALL_2(bpf_inode_storage_delete,
+	   struct bpf_map *, map, struct inode *, inode)
+{
+	if (!inode)
+		return -EINVAL;
+
+	/* This helper must only called from where the inode is gurranteed
+	 * to have a refcount and cannot be freed.
+	 */
+	return inode_storage_delete(inode, map);
+}
+
+static int notsupp_get_next_key(struct bpf_map *map, void *key,
+				void *next_key)
+{
+	return -ENOTSUPP;
+}
+
+static struct bpf_map *inode_storage_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_local_storage_map *smap;
+
+	smap = bpf_local_storage_map_alloc(attr);
+	if (IS_ERR(smap))
+		return ERR_CAST(smap);
+
+	smap->cache_idx = bpf_local_storage_cache_idx_get(&inode_cache);
+	return &smap->map;
+}
+
+static void inode_storage_map_free(struct bpf_map *map)
+{
+	struct bpf_local_storage_map *smap;
+
+	smap = (struct bpf_local_storage_map *)map;
+	bpf_local_storage_cache_idx_free(&inode_cache, smap->cache_idx);
+	bpf_local_storage_map_free(smap);
+}
+
+static int inode_storage_map_btf_id;
+const struct bpf_map_ops inode_storage_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = bpf_local_storage_map_alloc_check,
+	.map_alloc = inode_storage_map_alloc,
+	.map_free = inode_storage_map_free,
+	.map_get_next_key = notsupp_get_next_key,
+	.map_lookup_elem = bpf_fd_inode_storage_lookup_elem,
+	.map_update_elem = bpf_fd_inode_storage_update_elem,
+	.map_delete_elem = bpf_fd_inode_storage_delete_elem,
+	.map_check_btf = bpf_local_storage_map_check_btf,
+	.map_btf_name = "bpf_local_storage_map",
+	.map_btf_id = &inode_storage_map_btf_id,
+	.map_owner_storage_ptr = inode_storage_ptr,
+};
+
+BTF_ID_LIST_SINGLE(bpf_inode_storage_btf_ids, struct, inode)
+
+const struct bpf_func_proto bpf_inode_storage_get_proto = {
+	.func		= bpf_inode_storage_get,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_BTF_ID,
+	.arg2_btf_id	= &bpf_inode_storage_btf_ids[0],
+	.arg3_type	= ARG_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+const struct bpf_func_proto bpf_inode_storage_delete_proto = {
+	.func		= bpf_inode_storage_delete,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_BTF_ID,
+	.arg2_btf_id	= &bpf_inode_storage_btf_ids[0],
+};
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
new file mode 100644
index 000000000..e8957e911
--- /dev/null
+++ b/kernel/bpf/bpf_iter.c
@@ -0,0 +1,663 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 Facebook */
+
+#include <linux/fs.h>
+#include <linux/anon_inodes.h>
+#include <linux/filter.h>
+#include <linux/bpf.h>
+
+struct bpf_iter_target_info {
+	struct list_head list;
+	const struct bpf_iter_reg *reg_info;
+	u32 btf_id;	/* cached value */
+};
+
+struct bpf_iter_link {
+	struct bpf_link link;
+	struct bpf_iter_aux_info aux;
+	struct bpf_iter_target_info *tinfo;
+};
+
+struct bpf_iter_priv_data {
+	struct bpf_iter_target_info *tinfo;
+	const struct bpf_iter_seq_info *seq_info;
+	struct bpf_prog *prog;
+	u64 session_id;
+	u64 seq_num;
+	bool done_stop;
+	u8 target_private[] __aligned(8);
+};
+
+static struct list_head targets = LIST_HEAD_INIT(targets);
+static DEFINE_MUTEX(targets_mutex);
+
+/* protect bpf_iter_link changes */
+static DEFINE_MUTEX(link_mutex);
+
+/* incremented on every opened seq_file */
+static atomic64_t session_id;
+
+static int prepare_seq_file(struct file *file, struct bpf_iter_link *link,
+			    const struct bpf_iter_seq_info *seq_info);
+
+static void bpf_iter_inc_seq_num(struct seq_file *seq)
+{
+	struct bpf_iter_priv_data *iter_priv;
+
+	iter_priv = container_of(seq->private, struct bpf_iter_priv_data,
+				 target_private);
+	iter_priv->seq_num++;
+}
+
+static void bpf_iter_dec_seq_num(struct seq_file *seq)
+{
+	struct bpf_iter_priv_data *iter_priv;
+
+	iter_priv = container_of(seq->private, struct bpf_iter_priv_data,
+				 target_private);
+	iter_priv->seq_num--;
+}
+
+static void bpf_iter_done_stop(struct seq_file *seq)
+{
+	struct bpf_iter_priv_data *iter_priv;
+
+	iter_priv = container_of(seq->private, struct bpf_iter_priv_data,
+				 target_private);
+	iter_priv->done_stop = true;
+}
+
+/* maximum visited objects before bailing out */
+#define MAX_ITER_OBJECTS	1000000
+
+/* bpf_seq_read, a customized and simpler version for bpf iterator.
+ * no_llseek is assumed for this file.
+ * The following are differences from seq_read():
+ *  . fixed buffer size (PAGE_SIZE)
+ *  . assuming no_llseek
+ *  . stop() may call bpf program, handling potential overflow there
+ */
+static ssize_t bpf_seq_read(struct file *file, char __user *buf, size_t size,
+			    loff_t *ppos)
+{
+	struct seq_file *seq = file->private_data;
+	size_t n, offs, copied = 0;
+	int err = 0, num_objs = 0;
+	void *p;
+
+	mutex_lock(&seq->lock);
+
+	if (!seq->buf) {
+		seq->size = PAGE_SIZE << 3;
+		seq->buf = kvmalloc(seq->size, GFP_KERNEL);
+		if (!seq->buf) {
+			err = -ENOMEM;
+			goto done;
+		}
+	}
+
+	if (seq->count) {
+		n = min(seq->count, size);
+		err = copy_to_user(buf, seq->buf + seq->from, n);
+		if (err) {
+			err = -EFAULT;
+			goto done;
+		}
+		seq->count -= n;
+		seq->from += n;
+		copied = n;
+		goto done;
+	}
+
+	seq->from = 0;
+	p = seq->op->start(seq, &seq->index);
+	if (!p)
+		goto stop;
+	if (IS_ERR(p)) {
+		err = PTR_ERR(p);
+		seq->op->stop(seq, p);
+		seq->count = 0;
+		goto done;
+	}
+
+	err = seq->op->show(seq, p);
+	if (err > 0) {
+		/* object is skipped, decrease seq_num, so next
+		 * valid object can reuse the same seq_num.
+		 */
+		bpf_iter_dec_seq_num(seq);
+		seq->count = 0;
+	} else if (err < 0 || seq_has_overflowed(seq)) {
+		if (!err)
+			err = -E2BIG;
+		seq->op->stop(seq, p);
+		seq->count = 0;
+		goto done;
+	}
+
+	while (1) {
+		loff_t pos = seq->index;
+
+		num_objs++;
+		offs = seq->count;
+		p = seq->op->next(seq, p, &seq->index);
+		if (pos == seq->index) {
+			pr_info_ratelimited("buggy seq_file .next function %ps "
+				"did not updated position index\n",
+				seq->op->next);
+			seq->index++;
+		}
+
+		if (IS_ERR_OR_NULL(p))
+			break;
+
+		/* got a valid next object, increase seq_num */
+		bpf_iter_inc_seq_num(seq);
+
+		if (seq->count >= size)
+			break;
+
+		if (num_objs >= MAX_ITER_OBJECTS) {
+			if (offs == 0) {
+				err = -EAGAIN;
+				seq->op->stop(seq, p);
+				goto done;
+			}
+			break;
+		}
+
+		err = seq->op->show(seq, p);
+		if (err > 0) {
+			bpf_iter_dec_seq_num(seq);
+			seq->count = offs;
+		} else if (err < 0 || seq_has_overflowed(seq)) {
+			seq->count = offs;
+			if (offs == 0) {
+				if (!err)
+					err = -E2BIG;
+				seq->op->stop(seq, p);
+				goto done;
+			}
+			break;
+		}
+	}
+stop:
+	offs = seq->count;
+	/* bpf program called if !p */
+	seq->op->stop(seq, p);
+	if (!p) {
+		if (!seq_has_overflowed(seq)) {
+			bpf_iter_done_stop(seq);
+		} else {
+			seq->count = offs;
+			if (offs == 0) {
+				err = -E2BIG;
+				goto done;
+			}
+		}
+	}
+
+	n = min(seq->count, size);
+	err = copy_to_user(buf, seq->buf, n);
+	if (err) {
+		err = -EFAULT;
+		goto done;
+	}
+	copied = n;
+	seq->count -= n;
+	seq->from = n;
+done:
+	if (!copied)
+		copied = err;
+	else
+		*ppos += copied;
+	mutex_unlock(&seq->lock);
+	return copied;
+}
+
+static const struct bpf_iter_seq_info *
+__get_seq_info(struct bpf_iter_link *link)
+{
+	const struct bpf_iter_seq_info *seq_info;
+
+	if (link->aux.map) {
+		seq_info = link->aux.map->ops->iter_seq_info;
+		if (seq_info)
+			return seq_info;
+	}
+
+	return link->tinfo->reg_info->seq_info;
+}
+
+static int iter_open(struct inode *inode, struct file *file)
+{
+	struct bpf_iter_link *link = inode->i_private;
+
+	return prepare_seq_file(file, link, __get_seq_info(link));
+}
+
+static int iter_release(struct inode *inode, struct file *file)
+{
+	struct bpf_iter_priv_data *iter_priv;
+	struct seq_file *seq;
+
+	seq = file->private_data;
+	if (!seq)
+		return 0;
+
+	iter_priv = container_of(seq->private, struct bpf_iter_priv_data,
+				 target_private);
+
+	if (iter_priv->seq_info->fini_seq_private)
+		iter_priv->seq_info->fini_seq_private(seq->private);
+
+	bpf_prog_put(iter_priv->prog);
+	seq->private = iter_priv;
+
+	return seq_release_private(inode, file);
+}
+
+const struct file_operations bpf_iter_fops = {
+	.open		= iter_open,
+	.llseek		= no_llseek,
+	.read		= bpf_seq_read,
+	.release	= iter_release,
+};
+
+/* The argument reg_info will be cached in bpf_iter_target_info.
+ * The common practice is to declare target reg_info as
+ * a const static variable and passed as an argument to
+ * bpf_iter_reg_target().
+ */
+int bpf_iter_reg_target(const struct bpf_iter_reg *reg_info)
+{
+	struct bpf_iter_target_info *tinfo;
+
+	tinfo = kzalloc(sizeof(*tinfo), GFP_KERNEL);
+	if (!tinfo)
+		return -ENOMEM;
+
+	tinfo->reg_info = reg_info;
+	INIT_LIST_HEAD(&tinfo->list);
+
+	mutex_lock(&targets_mutex);
+	list_add(&tinfo->list, &targets);
+	mutex_unlock(&targets_mutex);
+
+	return 0;
+}
+
+void bpf_iter_unreg_target(const struct bpf_iter_reg *reg_info)
+{
+	struct bpf_iter_target_info *tinfo;
+	bool found = false;
+
+	mutex_lock(&targets_mutex);
+	list_for_each_entry(tinfo, &targets, list) {
+		if (reg_info == tinfo->reg_info) {
+			list_del(&tinfo->list);
+			kfree(tinfo);
+			found = true;
+			break;
+		}
+	}
+	mutex_unlock(&targets_mutex);
+
+	WARN_ON(found == false);
+}
+
+static void cache_btf_id(struct bpf_iter_target_info *tinfo,
+			 struct bpf_prog *prog)
+{
+	tinfo->btf_id = prog->aux->attach_btf_id;
+}
+
+bool bpf_iter_prog_supported(struct bpf_prog *prog)
+{
+	const char *attach_fname = prog->aux->attach_func_name;
+	u32 prog_btf_id = prog->aux->attach_btf_id;
+	const char *prefix = BPF_ITER_FUNC_PREFIX;
+	struct bpf_iter_target_info *tinfo;
+	int prefix_len = strlen(prefix);
+	bool supported = false;
+
+	if (strncmp(attach_fname, prefix, prefix_len))
+		return false;
+
+	mutex_lock(&targets_mutex);
+	list_for_each_entry(tinfo, &targets, list) {
+		if (tinfo->btf_id && tinfo->btf_id == prog_btf_id) {
+			supported = true;
+			break;
+		}
+		if (!strcmp(attach_fname + prefix_len, tinfo->reg_info->target)) {
+			cache_btf_id(tinfo, prog);
+			supported = true;
+			break;
+		}
+	}
+	mutex_unlock(&targets_mutex);
+
+	if (supported) {
+		prog->aux->ctx_arg_info_size = tinfo->reg_info->ctx_arg_info_size;
+		prog->aux->ctx_arg_info = tinfo->reg_info->ctx_arg_info;
+	}
+
+	return supported;
+}
+
+static void bpf_iter_link_release(struct bpf_link *link)
+{
+	struct bpf_iter_link *iter_link =
+		container_of(link, struct bpf_iter_link, link);
+
+	if (iter_link->tinfo->reg_info->detach_target)
+		iter_link->tinfo->reg_info->detach_target(&iter_link->aux);
+}
+
+static void bpf_iter_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_iter_link *iter_link =
+		container_of(link, struct bpf_iter_link, link);
+
+	kfree(iter_link);
+}
+
+static int bpf_iter_link_replace(struct bpf_link *link,
+				 struct bpf_prog *new_prog,
+				 struct bpf_prog *old_prog)
+{
+	int ret = 0;
+
+	mutex_lock(&link_mutex);
+	if (old_prog && link->prog != old_prog) {
+		ret = -EPERM;
+		goto out_unlock;
+	}
+
+	if (link->prog->type != new_prog->type ||
+	    link->prog->expected_attach_type != new_prog->expected_attach_type ||
+	    link->prog->aux->attach_btf_id != new_prog->aux->attach_btf_id) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	old_prog = xchg(&link->prog, new_prog);
+	bpf_prog_put(old_prog);
+
+out_unlock:
+	mutex_unlock(&link_mutex);
+	return ret;
+}
+
+static void bpf_iter_link_show_fdinfo(const struct bpf_link *link,
+				      struct seq_file *seq)
+{
+	struct bpf_iter_link *iter_link =
+		container_of(link, struct bpf_iter_link, link);
+	bpf_iter_show_fdinfo_t show_fdinfo;
+
+	seq_printf(seq,
+		   "target_name:\t%s\n",
+		   iter_link->tinfo->reg_info->target);
+
+	show_fdinfo = iter_link->tinfo->reg_info->show_fdinfo;
+	if (show_fdinfo)
+		show_fdinfo(&iter_link->aux, seq);
+}
+
+static int bpf_iter_link_fill_link_info(const struct bpf_link *link,
+					struct bpf_link_info *info)
+{
+	struct bpf_iter_link *iter_link =
+		container_of(link, struct bpf_iter_link, link);
+	char __user *ubuf = u64_to_user_ptr(info->iter.target_name);
+	bpf_iter_fill_link_info_t fill_link_info;
+	u32 ulen = info->iter.target_name_len;
+	const char *target_name;
+	u32 target_len;
+
+	if (!ulen ^ !ubuf)
+		return -EINVAL;
+
+	target_name = iter_link->tinfo->reg_info->target;
+	target_len =  strlen(target_name);
+	info->iter.target_name_len = target_len + 1;
+
+	if (ubuf) {
+		if (ulen >= target_len + 1) {
+			if (copy_to_user(ubuf, target_name, target_len + 1))
+				return -EFAULT;
+		} else {
+			char zero = '\0';
+
+			if (copy_to_user(ubuf, target_name, ulen - 1))
+				return -EFAULT;
+			if (put_user(zero, ubuf + ulen - 1))
+				return -EFAULT;
+			return -ENOSPC;
+		}
+	}
+
+	fill_link_info = iter_link->tinfo->reg_info->fill_link_info;
+	if (fill_link_info)
+		return fill_link_info(&iter_link->aux, info);
+
+	return 0;
+}
+
+static const struct bpf_link_ops bpf_iter_link_lops = {
+	.release = bpf_iter_link_release,
+	.dealloc = bpf_iter_link_dealloc,
+	.update_prog = bpf_iter_link_replace,
+	.show_fdinfo = bpf_iter_link_show_fdinfo,
+	.fill_link_info = bpf_iter_link_fill_link_info,
+};
+
+bool bpf_link_is_iter(struct bpf_link *link)
+{
+	return link->ops == &bpf_iter_link_lops;
+}
+
+int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	union bpf_iter_link_info __user *ulinfo;
+	struct bpf_link_primer link_primer;
+	struct bpf_iter_target_info *tinfo;
+	union bpf_iter_link_info linfo;
+	struct bpf_iter_link *link;
+	u32 prog_btf_id, linfo_len;
+	bool existed = false;
+	int err;
+
+	if (attr->link_create.target_fd || attr->link_create.flags)
+		return -EINVAL;
+
+	memset(&linfo, 0, sizeof(union bpf_iter_link_info));
+
+	ulinfo = u64_to_user_ptr(attr->link_create.iter_info);
+	linfo_len = attr->link_create.iter_info_len;
+	if (!ulinfo ^ !linfo_len)
+		return -EINVAL;
+
+	if (ulinfo) {
+		err = bpf_check_uarg_tail_zero(ulinfo, sizeof(linfo),
+					       linfo_len);
+		if (err)
+			return err;
+		linfo_len = min_t(u32, linfo_len, sizeof(linfo));
+		if (copy_from_user(&linfo, ulinfo, linfo_len))
+			return -EFAULT;
+	}
+
+	prog_btf_id = prog->aux->attach_btf_id;
+	mutex_lock(&targets_mutex);
+	list_for_each_entry(tinfo, &targets, list) {
+		if (tinfo->btf_id == prog_btf_id) {
+			existed = true;
+			break;
+		}
+	}
+	mutex_unlock(&targets_mutex);
+	if (!existed)
+		return -ENOENT;
+
+	link = kzalloc(sizeof(*link), GFP_USER | __GFP_NOWARN);
+	if (!link)
+		return -ENOMEM;
+
+	bpf_link_init(&link->link, BPF_LINK_TYPE_ITER, &bpf_iter_link_lops, prog);
+	link->tinfo = tinfo;
+
+	err  = bpf_link_prime(&link->link, &link_primer);
+	if (err) {
+		kfree(link);
+		return err;
+	}
+
+	if (tinfo->reg_info->attach_target) {
+		err = tinfo->reg_info->attach_target(prog, &linfo, &link->aux);
+		if (err) {
+			bpf_link_cleanup(&link_primer);
+			return err;
+		}
+	}
+
+	return bpf_link_settle(&link_primer);
+}
+
+static void init_seq_meta(struct bpf_iter_priv_data *priv_data,
+			  struct bpf_iter_target_info *tinfo,
+			  const struct bpf_iter_seq_info *seq_info,
+			  struct bpf_prog *prog)
+{
+	priv_data->tinfo = tinfo;
+	priv_data->seq_info = seq_info;
+	priv_data->prog = prog;
+	priv_data->session_id = atomic64_inc_return(&session_id);
+	priv_data->seq_num = 0;
+	priv_data->done_stop = false;
+}
+
+static int prepare_seq_file(struct file *file, struct bpf_iter_link *link,
+			    const struct bpf_iter_seq_info *seq_info)
+{
+	struct bpf_iter_priv_data *priv_data;
+	struct bpf_iter_target_info *tinfo;
+	struct bpf_prog *prog;
+	u32 total_priv_dsize;
+	struct seq_file *seq;
+	int err = 0;
+
+	mutex_lock(&link_mutex);
+	prog = link->link.prog;
+	bpf_prog_inc(prog);
+	mutex_unlock(&link_mutex);
+
+	tinfo = link->tinfo;
+	total_priv_dsize = offsetof(struct bpf_iter_priv_data, target_private) +
+			   seq_info->seq_priv_size;
+	priv_data = __seq_open_private(file, seq_info->seq_ops,
+				       total_priv_dsize);
+	if (!priv_data) {
+		err = -ENOMEM;
+		goto release_prog;
+	}
+
+	if (seq_info->init_seq_private) {
+		err = seq_info->init_seq_private(priv_data->target_private, &link->aux);
+		if (err)
+			goto release_seq_file;
+	}
+
+	init_seq_meta(priv_data, tinfo, seq_info, prog);
+	seq = file->private_data;
+	seq->private = priv_data->target_private;
+
+	return 0;
+
+release_seq_file:
+	seq_release_private(file->f_inode, file);
+	file->private_data = NULL;
+release_prog:
+	bpf_prog_put(prog);
+	return err;
+}
+
+int bpf_iter_new_fd(struct bpf_link *link)
+{
+	struct bpf_iter_link *iter_link;
+	struct file *file;
+	unsigned int flags;
+	int err, fd;
+
+	if (link->ops != &bpf_iter_link_lops)
+		return -EINVAL;
+
+	flags = O_RDONLY | O_CLOEXEC;
+	fd = get_unused_fd_flags(flags);
+	if (fd < 0)
+		return fd;
+
+	file = anon_inode_getfile("bpf_iter", &bpf_iter_fops, NULL, flags);
+	if (IS_ERR(file)) {
+		err = PTR_ERR(file);
+		goto free_fd;
+	}
+
+	iter_link = container_of(link, struct bpf_iter_link, link);
+	err = prepare_seq_file(file, iter_link, __get_seq_info(iter_link));
+	if (err)
+		goto free_file;
+
+	fd_install(fd, file);
+	return fd;
+
+free_file:
+	fput(file);
+free_fd:
+	put_unused_fd(fd);
+	return err;
+}
+
+struct bpf_prog *bpf_iter_get_info(struct bpf_iter_meta *meta, bool in_stop)
+{
+	struct bpf_iter_priv_data *iter_priv;
+	struct seq_file *seq;
+	void *seq_priv;
+
+	seq = meta->seq;
+	if (seq->file->f_op != &bpf_iter_fops)
+		return NULL;
+
+	seq_priv = seq->private;
+	iter_priv = container_of(seq_priv, struct bpf_iter_priv_data,
+				 target_private);
+
+	if (in_stop && iter_priv->done_stop)
+		return NULL;
+
+	meta->session_id = iter_priv->session_id;
+	meta->seq_num = iter_priv->seq_num;
+
+	return iter_priv->prog;
+}
+
+int bpf_iter_run_prog(struct bpf_prog *prog, void *ctx)
+{
+	int ret;
+
+	rcu_read_lock();
+	migrate_disable();
+	ret = BPF_PROG_RUN(prog, ctx);
+	migrate_enable();
+	rcu_read_unlock();
+
+	/* bpf program can only return 0 or 1:
+	 *  0 : okay
+	 *  1 : retry the same object
+	 * The bpf_iter_run_prog() return value
+	 * will be seq_ops->show() return value.
+	 */
+	return ret == 0 ? 0 : -EAGAIN;
+}
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
new file mode 100644
index 000000000..f75396572
--- /dev/null
+++ b/kernel/bpf/bpf_local_storage.c
@@ -0,0 +1,610 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook  */
+#include <linux/rculist.h>
+#include <linux/list.h>
+#include <linux/hash.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/bpf.h>
+#include <linux/btf_ids.h>
+#include <linux/bpf_local_storage.h>
+#include <net/sock.h>
+#include <uapi/linux/sock_diag.h>
+#include <uapi/linux/btf.h>
+
+#define BPF_LOCAL_STORAGE_CREATE_FLAG_MASK (BPF_F_NO_PREALLOC | BPF_F_CLONE)
+
+static struct bpf_local_storage_map_bucket *
+select_bucket(struct bpf_local_storage_map *smap,
+	      struct bpf_local_storage_elem *selem)
+{
+	return &smap->buckets[hash_ptr(selem, smap->bucket_log)];
+}
+
+static int mem_charge(struct bpf_local_storage_map *smap, void *owner, u32 size)
+{
+	struct bpf_map *map = &smap->map;
+
+	if (!map->ops->map_local_storage_charge)
+		return 0;
+
+	return map->ops->map_local_storage_charge(smap, owner, size);
+}
+
+static void mem_uncharge(struct bpf_local_storage_map *smap, void *owner,
+			 u32 size)
+{
+	struct bpf_map *map = &smap->map;
+
+	if (map->ops->map_local_storage_uncharge)
+		map->ops->map_local_storage_uncharge(smap, owner, size);
+}
+
+static struct bpf_local_storage __rcu **
+owner_storage(struct bpf_local_storage_map *smap, void *owner)
+{
+	struct bpf_map *map = &smap->map;
+
+	return map->ops->map_owner_storage_ptr(owner);
+}
+
+static bool selem_linked_to_storage_lockless(const struct bpf_local_storage_elem *selem)
+{
+	return !hlist_unhashed_lockless(&selem->snode);
+}
+
+static bool selem_linked_to_storage(const struct bpf_local_storage_elem *selem)
+{
+	return !hlist_unhashed(&selem->snode);
+}
+
+static bool selem_linked_to_map_lockless(const struct bpf_local_storage_elem *selem)
+{
+	return !hlist_unhashed_lockless(&selem->map_node);
+}
+
+static bool selem_linked_to_map(const struct bpf_local_storage_elem *selem)
+{
+	return !hlist_unhashed(&selem->map_node);
+}
+
+struct bpf_local_storage_elem *
+bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner,
+		void *value, bool charge_mem)
+{
+	struct bpf_local_storage_elem *selem;
+
+	if (charge_mem && mem_charge(smap, owner, smap->elem_size))
+		return NULL;
+
+	selem = kzalloc(smap->elem_size, GFP_ATOMIC | __GFP_NOWARN);
+	if (selem) {
+		if (value)
+			copy_map_value(&smap->map, SDATA(selem)->data, value);
+		return selem;
+	}
+
+	if (charge_mem)
+		mem_uncharge(smap, owner, smap->elem_size);
+
+	return NULL;
+}
+
+/* local_storage->lock must be held and selem->local_storage == local_storage.
+ * The caller must ensure selem->smap is still valid to be
+ * dereferenced for its smap->elem_size and smap->cache_idx.
+ */
+bool bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_storage,
+				     struct bpf_local_storage_elem *selem,
+				     bool uncharge_mem)
+{
+	struct bpf_local_storage_map *smap;
+	bool free_local_storage;
+	void *owner;
+
+	smap = rcu_dereference(SDATA(selem)->smap);
+	owner = local_storage->owner;
+
+	/* All uncharging on the owner must be done first.
+	 * The owner may be freed once the last selem is unlinked
+	 * from local_storage.
+	 */
+	if (uncharge_mem)
+		mem_uncharge(smap, owner, smap->elem_size);
+
+	free_local_storage = hlist_is_singular_node(&selem->snode,
+						    &local_storage->list);
+	if (free_local_storage) {
+		mem_uncharge(smap, owner, sizeof(struct bpf_local_storage));
+		local_storage->owner = NULL;
+
+		/* After this RCU_INIT, owner may be freed and cannot be used */
+		RCU_INIT_POINTER(*owner_storage(smap, owner), NULL);
+
+		/* local_storage is not freed now.  local_storage->lock is
+		 * still held and raw_spin_unlock_bh(&local_storage->lock)
+		 * will be done by the caller.
+		 *
+		 * Although the unlock will be done under
+		 * rcu_read_lock(),  it is more intutivie to
+		 * read if kfree_rcu(local_storage, rcu) is done
+		 * after the raw_spin_unlock_bh(&local_storage->lock).
+		 *
+		 * Hence, a "bool free_local_storage" is returned
+		 * to the caller which then calls the kfree_rcu()
+		 * after unlock.
+		 */
+	}
+	hlist_del_init_rcu(&selem->snode);
+	if (rcu_access_pointer(local_storage->cache[smap->cache_idx]) ==
+	    SDATA(selem))
+		RCU_INIT_POINTER(local_storage->cache[smap->cache_idx], NULL);
+
+	kfree_rcu(selem, rcu);
+
+	return free_local_storage;
+}
+
+static void __bpf_selem_unlink_storage(struct bpf_local_storage_elem *selem)
+{
+	struct bpf_local_storage *local_storage;
+	bool free_local_storage = false;
+
+	if (unlikely(!selem_linked_to_storage_lockless(selem)))
+		/* selem has already been unlinked from sk */
+		return;
+
+	local_storage = rcu_dereference(selem->local_storage);
+	raw_spin_lock_bh(&local_storage->lock);
+	if (likely(selem_linked_to_storage(selem)))
+		free_local_storage = bpf_selem_unlink_storage_nolock(
+			local_storage, selem, true);
+	raw_spin_unlock_bh(&local_storage->lock);
+
+	if (free_local_storage)
+		kfree_rcu(local_storage, rcu);
+}
+
+void bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage,
+				   struct bpf_local_storage_elem *selem)
+{
+	RCU_INIT_POINTER(selem->local_storage, local_storage);
+	hlist_add_head_rcu(&selem->snode, &local_storage->list);
+}
+
+void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem)
+{
+	struct bpf_local_storage_map *smap;
+	struct bpf_local_storage_map_bucket *b;
+
+	if (unlikely(!selem_linked_to_map_lockless(selem)))
+		/* selem has already be unlinked from smap */
+		return;
+
+	smap = rcu_dereference(SDATA(selem)->smap);
+	b = select_bucket(smap, selem);
+	raw_spin_lock_bh(&b->lock);
+	if (likely(selem_linked_to_map(selem)))
+		hlist_del_init_rcu(&selem->map_node);
+	raw_spin_unlock_bh(&b->lock);
+}
+
+void bpf_selem_link_map(struct bpf_local_storage_map *smap,
+			struct bpf_local_storage_elem *selem)
+{
+	struct bpf_local_storage_map_bucket *b = select_bucket(smap, selem);
+
+	raw_spin_lock_bh(&b->lock);
+	RCU_INIT_POINTER(SDATA(selem)->smap, smap);
+	hlist_add_head_rcu(&selem->map_node, &b->list);
+	raw_spin_unlock_bh(&b->lock);
+}
+
+void bpf_selem_unlink(struct bpf_local_storage_elem *selem)
+{
+	/* Always unlink from map before unlinking from local_storage
+	 * because selem will be freed after successfully unlinked from
+	 * the local_storage.
+	 */
+	bpf_selem_unlink_map(selem);
+	__bpf_selem_unlink_storage(selem);
+}
+
+struct bpf_local_storage_data *
+bpf_local_storage_lookup(struct bpf_local_storage *local_storage,
+			 struct bpf_local_storage_map *smap,
+			 bool cacheit_lockit)
+{
+	struct bpf_local_storage_data *sdata;
+	struct bpf_local_storage_elem *selem;
+
+	/* Fast path (cache hit) */
+	sdata = rcu_dereference(local_storage->cache[smap->cache_idx]);
+	if (sdata && rcu_access_pointer(sdata->smap) == smap)
+		return sdata;
+
+	/* Slow path (cache miss) */
+	hlist_for_each_entry_rcu(selem, &local_storage->list, snode)
+		if (rcu_access_pointer(SDATA(selem)->smap) == smap)
+			break;
+
+	if (!selem)
+		return NULL;
+
+	sdata = SDATA(selem);
+	if (cacheit_lockit) {
+		/* spinlock is needed to avoid racing with the
+		 * parallel delete.  Otherwise, publishing an already
+		 * deleted sdata to the cache will become a use-after-free
+		 * problem in the next bpf_local_storage_lookup().
+		 */
+		raw_spin_lock_bh(&local_storage->lock);
+		if (selem_linked_to_storage(selem))
+			rcu_assign_pointer(local_storage->cache[smap->cache_idx],
+					   sdata);
+		raw_spin_unlock_bh(&local_storage->lock);
+	}
+
+	return sdata;
+}
+
+static int check_flags(const struct bpf_local_storage_data *old_sdata,
+		       u64 map_flags)
+{
+	if (old_sdata && (map_flags & ~BPF_F_LOCK) == BPF_NOEXIST)
+		/* elem already exists */
+		return -EEXIST;
+
+	if (!old_sdata && (map_flags & ~BPF_F_LOCK) == BPF_EXIST)
+		/* elem doesn't exist, cannot update it */
+		return -ENOENT;
+
+	return 0;
+}
+
+int bpf_local_storage_alloc(void *owner,
+			    struct bpf_local_storage_map *smap,
+			    struct bpf_local_storage_elem *first_selem)
+{
+	struct bpf_local_storage *prev_storage, *storage;
+	struct bpf_local_storage **owner_storage_ptr;
+	int err;
+
+	err = mem_charge(smap, owner, sizeof(*storage));
+	if (err)
+		return err;
+
+	storage = kzalloc(sizeof(*storage), GFP_ATOMIC | __GFP_NOWARN);
+	if (!storage) {
+		err = -ENOMEM;
+		goto uncharge;
+	}
+
+	INIT_HLIST_HEAD(&storage->list);
+	raw_spin_lock_init(&storage->lock);
+	storage->owner = owner;
+
+	bpf_selem_link_storage_nolock(storage, first_selem);
+	bpf_selem_link_map(smap, first_selem);
+
+	owner_storage_ptr =
+		(struct bpf_local_storage **)owner_storage(smap, owner);
+	/* Publish storage to the owner.
+	 * Instead of using any lock of the kernel object (i.e. owner),
+	 * cmpxchg will work with any kernel object regardless what
+	 * the running context is, bh, irq...etc.
+	 *
+	 * From now on, the owner->storage pointer (e.g. sk->sk_bpf_storage)
+	 * is protected by the storage->lock.  Hence, when freeing
+	 * the owner->storage, the storage->lock must be held before
+	 * setting owner->storage ptr to NULL.
+	 */
+	prev_storage = cmpxchg(owner_storage_ptr, NULL, storage);
+	if (unlikely(prev_storage)) {
+		bpf_selem_unlink_map(first_selem);
+		err = -EAGAIN;
+		goto uncharge;
+
+		/* Note that even first_selem was linked to smap's
+		 * bucket->list, first_selem can be freed immediately
+		 * (instead of kfree_rcu) because
+		 * bpf_local_storage_map_free() does a
+		 * synchronize_rcu() before walking the bucket->list.
+		 * Hence, no one is accessing selem from the
+		 * bucket->list under rcu_read_lock().
+		 */
+	}
+
+	return 0;
+
+uncharge:
+	kfree(storage);
+	mem_uncharge(smap, owner, sizeof(*storage));
+	return err;
+}
+
+/* sk cannot be going away because it is linking new elem
+ * to sk->sk_bpf_storage. (i.e. sk->sk_refcnt cannot be 0).
+ * Otherwise, it will become a leak (and other memory issues
+ * during map destruction).
+ */
+struct bpf_local_storage_data *
+bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap,
+			 void *value, u64 map_flags)
+{
+	struct bpf_local_storage_data *old_sdata = NULL;
+	struct bpf_local_storage_elem *selem;
+	struct bpf_local_storage *local_storage;
+	int err;
+
+	/* BPF_EXIST and BPF_NOEXIST cannot be both set */
+	if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST) ||
+	    /* BPF_F_LOCK can only be used in a value with spin_lock */
+	    unlikely((map_flags & BPF_F_LOCK) &&
+		     !map_value_has_spin_lock(&smap->map)))
+		return ERR_PTR(-EINVAL);
+
+	local_storage = rcu_dereference(*owner_storage(smap, owner));
+	if (!local_storage || hlist_empty(&local_storage->list)) {
+		/* Very first elem for the owner */
+		err = check_flags(NULL, map_flags);
+		if (err)
+			return ERR_PTR(err);
+
+		selem = bpf_selem_alloc(smap, owner, value, true);
+		if (!selem)
+			return ERR_PTR(-ENOMEM);
+
+		err = bpf_local_storage_alloc(owner, smap, selem);
+		if (err) {
+			kfree(selem);
+			mem_uncharge(smap, owner, smap->elem_size);
+			return ERR_PTR(err);
+		}
+
+		return SDATA(selem);
+	}
+
+	if ((map_flags & BPF_F_LOCK) && !(map_flags & BPF_NOEXIST)) {
+		/* Hoping to find an old_sdata to do inline update
+		 * such that it can avoid taking the local_storage->lock
+		 * and changing the lists.
+		 */
+		old_sdata =
+			bpf_local_storage_lookup(local_storage, smap, false);
+		err = check_flags(old_sdata, map_flags);
+		if (err)
+			return ERR_PTR(err);
+		if (old_sdata && selem_linked_to_storage_lockless(SELEM(old_sdata))) {
+			copy_map_value_locked(&smap->map, old_sdata->data,
+					      value, false);
+			return old_sdata;
+		}
+	}
+
+	raw_spin_lock_bh(&local_storage->lock);
+
+	/* Recheck local_storage->list under local_storage->lock */
+	if (unlikely(hlist_empty(&local_storage->list))) {
+		/* A parallel del is happening and local_storage is going
+		 * away.  It has just been checked before, so very
+		 * unlikely.  Return instead of retry to keep things
+		 * simple.
+		 */
+		err = -EAGAIN;
+		goto unlock_err;
+	}
+
+	old_sdata = bpf_local_storage_lookup(local_storage, smap, false);
+	err = check_flags(old_sdata, map_flags);
+	if (err)
+		goto unlock_err;
+
+	if (old_sdata && (map_flags & BPF_F_LOCK)) {
+		copy_map_value_locked(&smap->map, old_sdata->data, value,
+				      false);
+		selem = SELEM(old_sdata);
+		goto unlock;
+	}
+
+	/* local_storage->lock is held.  Hence, we are sure
+	 * we can unlink and uncharge the old_sdata successfully
+	 * later.  Hence, instead of charging the new selem now
+	 * and then uncharge the old selem later (which may cause
+	 * a potential but unnecessary charge failure),  avoid taking
+	 * a charge at all here (the "!old_sdata" check) and the
+	 * old_sdata will not be uncharged later during
+	 * bpf_selem_unlink_storage_nolock().
+	 */
+	selem = bpf_selem_alloc(smap, owner, value, !old_sdata);
+	if (!selem) {
+		err = -ENOMEM;
+		goto unlock_err;
+	}
+
+	/* First, link the new selem to the map */
+	bpf_selem_link_map(smap, selem);
+
+	/* Second, link (and publish) the new selem to local_storage */
+	bpf_selem_link_storage_nolock(local_storage, selem);
+
+	/* Third, remove old selem, SELEM(old_sdata) */
+	if (old_sdata) {
+		bpf_selem_unlink_map(SELEM(old_sdata));
+		bpf_selem_unlink_storage_nolock(local_storage, SELEM(old_sdata),
+						false);
+	}
+
+unlock:
+	raw_spin_unlock_bh(&local_storage->lock);
+	return SDATA(selem);
+
+unlock_err:
+	raw_spin_unlock_bh(&local_storage->lock);
+	return ERR_PTR(err);
+}
+
+u16 bpf_local_storage_cache_idx_get(struct bpf_local_storage_cache *cache)
+{
+	u64 min_usage = U64_MAX;
+	u16 i, res = 0;
+
+	spin_lock(&cache->idx_lock);
+
+	for (i = 0; i < BPF_LOCAL_STORAGE_CACHE_SIZE; i++) {
+		if (cache->idx_usage_counts[i] < min_usage) {
+			min_usage = cache->idx_usage_counts[i];
+			res = i;
+
+			/* Found a free cache_idx */
+			if (!min_usage)
+				break;
+		}
+	}
+	cache->idx_usage_counts[res]++;
+
+	spin_unlock(&cache->idx_lock);
+
+	return res;
+}
+
+void bpf_local_storage_cache_idx_free(struct bpf_local_storage_cache *cache,
+				      u16 idx)
+{
+	spin_lock(&cache->idx_lock);
+	cache->idx_usage_counts[idx]--;
+	spin_unlock(&cache->idx_lock);
+}
+
+void bpf_local_storage_map_free(struct bpf_local_storage_map *smap)
+{
+	struct bpf_local_storage_elem *selem;
+	struct bpf_local_storage_map_bucket *b;
+	unsigned int i;
+
+	/* Note that this map might be concurrently cloned from
+	 * bpf_sk_storage_clone. Wait for any existing bpf_sk_storage_clone
+	 * RCU read section to finish before proceeding. New RCU
+	 * read sections should be prevented via bpf_map_inc_not_zero.
+	 */
+	synchronize_rcu();
+
+	/* bpf prog and the userspace can no longer access this map
+	 * now.  No new selem (of this map) can be added
+	 * to the owner->storage or to the map bucket's list.
+	 *
+	 * The elem of this map can be cleaned up here
+	 * or when the storage is freed e.g.
+	 * by bpf_sk_storage_free() during __sk_destruct().
+	 */
+	for (i = 0; i < (1U << smap->bucket_log); i++) {
+		b = &smap->buckets[i];
+
+		rcu_read_lock();
+		/* No one is adding to b->list now */
+		while ((selem = hlist_entry_safe(
+				rcu_dereference_raw(hlist_first_rcu(&b->list)),
+				struct bpf_local_storage_elem, map_node))) {
+			bpf_selem_unlink(selem);
+			cond_resched_rcu();
+		}
+		rcu_read_unlock();
+	}
+
+	/* While freeing the storage we may still need to access the map.
+	 *
+	 * e.g. when bpf_sk_storage_free() has unlinked selem from the map
+	 * which then made the above while((selem = ...)) loop
+	 * exit immediately.
+	 *
+	 * However, while freeing the storage one still needs to access the
+	 * smap->elem_size to do the uncharging in
+	 * bpf_selem_unlink_storage_nolock().
+	 *
+	 * Hence, wait another rcu grace period for the storage to be freed.
+	 */
+	synchronize_rcu();
+
+	kvfree(smap->buckets);
+	kfree(smap);
+}
+
+int bpf_local_storage_map_alloc_check(union bpf_attr *attr)
+{
+	if (attr->map_flags & ~BPF_LOCAL_STORAGE_CREATE_FLAG_MASK ||
+	    !(attr->map_flags & BPF_F_NO_PREALLOC) ||
+	    attr->max_entries ||
+	    attr->key_size != sizeof(int) || !attr->value_size ||
+	    /* Enforce BTF for userspace sk dumping */
+	    !attr->btf_key_type_id || !attr->btf_value_type_id)
+		return -EINVAL;
+
+	if (!bpf_capable())
+		return -EPERM;
+
+	if (attr->value_size > BPF_LOCAL_STORAGE_MAX_VALUE_SIZE)
+		return -E2BIG;
+
+	return 0;
+}
+
+struct bpf_local_storage_map *bpf_local_storage_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_local_storage_map *smap;
+	unsigned int i;
+	u32 nbuckets;
+	u64 cost;
+	int ret;
+
+	smap = kzalloc(sizeof(*smap), GFP_USER | __GFP_NOWARN);
+	if (!smap)
+		return ERR_PTR(-ENOMEM);
+	bpf_map_init_from_attr(&smap->map, attr);
+
+	nbuckets = roundup_pow_of_two(num_possible_cpus());
+	/* Use at least 2 buckets, select_bucket() is undefined behavior with 1 bucket */
+	nbuckets = max_t(u32, 2, nbuckets);
+	smap->bucket_log = ilog2(nbuckets);
+	cost = sizeof(*smap->buckets) * nbuckets + sizeof(*smap);
+
+	ret = bpf_map_charge_init(&smap->map.memory, cost);
+	if (ret < 0) {
+		kfree(smap);
+		return ERR_PTR(ret);
+	}
+
+	smap->buckets = kvcalloc(sizeof(*smap->buckets), nbuckets,
+				 GFP_USER | __GFP_NOWARN);
+	if (!smap->buckets) {
+		bpf_map_charge_finish(&smap->map.memory);
+		kfree(smap);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	for (i = 0; i < nbuckets; i++) {
+		INIT_HLIST_HEAD(&smap->buckets[i].list);
+		raw_spin_lock_init(&smap->buckets[i].lock);
+	}
+
+	smap->elem_size =
+		sizeof(struct bpf_local_storage_elem) + attr->value_size;
+
+	return smap;
+}
+
+int bpf_local_storage_map_check_btf(const struct bpf_map *map,
+				    const struct btf *btf,
+				    const struct btf_type *key_type,
+				    const struct btf_type *value_type)
+{
+	u32 int_data;
+
+	if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
+		return -EINVAL;
+
+	int_data = *(u32 *)(key_type + 1);
+	if (BTF_INT_BITS(int_data) != 32 || BTF_INT_OFFSET(int_data))
+		return -EINVAL;
+
+	return 0;
+}
diff --git a/kernel/bpf/bpf_lru_list.c b/kernel/bpf/bpf_lru_list.c
new file mode 100644
index 000000000..3dabdd137
--- /dev/null
+++ b/kernel/bpf/bpf_lru_list.c
@@ -0,0 +1,700 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <linux/cpumask.h>
+#include <linux/spinlock.h>
+#include <linux/percpu.h>
+
+#include "bpf_lru_list.h"
+
+#define LOCAL_FREE_TARGET		(128)
+#define LOCAL_NR_SCANS			LOCAL_FREE_TARGET
+
+#define PERCPU_FREE_TARGET		(4)
+#define PERCPU_NR_SCANS			PERCPU_FREE_TARGET
+
+/* Helpers to get the local list index */
+#define LOCAL_LIST_IDX(t)	((t) - BPF_LOCAL_LIST_T_OFFSET)
+#define LOCAL_FREE_LIST_IDX	LOCAL_LIST_IDX(BPF_LRU_LOCAL_LIST_T_FREE)
+#define LOCAL_PENDING_LIST_IDX	LOCAL_LIST_IDX(BPF_LRU_LOCAL_LIST_T_PENDING)
+#define IS_LOCAL_LIST_TYPE(t)	((t) >= BPF_LOCAL_LIST_T_OFFSET)
+
+static int get_next_cpu(int cpu)
+{
+	cpu = cpumask_next(cpu, cpu_possible_mask);
+	if (cpu >= nr_cpu_ids)
+		cpu = cpumask_first(cpu_possible_mask);
+	return cpu;
+}
+
+/* Local list helpers */
+static struct list_head *local_free_list(struct bpf_lru_locallist *loc_l)
+{
+	return &loc_l->lists[LOCAL_FREE_LIST_IDX];
+}
+
+static struct list_head *local_pending_list(struct bpf_lru_locallist *loc_l)
+{
+	return &loc_l->lists[LOCAL_PENDING_LIST_IDX];
+}
+
+/* bpf_lru_node helpers */
+static bool bpf_lru_node_is_ref(const struct bpf_lru_node *node)
+{
+	return READ_ONCE(node->ref);
+}
+
+static void bpf_lru_node_clear_ref(struct bpf_lru_node *node)
+{
+	WRITE_ONCE(node->ref, 0);
+}
+
+static void bpf_lru_list_count_inc(struct bpf_lru_list *l,
+				   enum bpf_lru_list_type type)
+{
+	if (type < NR_BPF_LRU_LIST_COUNT)
+		l->counts[type]++;
+}
+
+static void bpf_lru_list_count_dec(struct bpf_lru_list *l,
+				   enum bpf_lru_list_type type)
+{
+	if (type < NR_BPF_LRU_LIST_COUNT)
+		l->counts[type]--;
+}
+
+static void __bpf_lru_node_move_to_free(struct bpf_lru_list *l,
+					struct bpf_lru_node *node,
+					struct list_head *free_list,
+					enum bpf_lru_list_type tgt_free_type)
+{
+	if (WARN_ON_ONCE(IS_LOCAL_LIST_TYPE(node->type)))
+		return;
+
+	/* If the removing node is the next_inactive_rotation candidate,
+	 * move the next_inactive_rotation pointer also.
+	 */
+	if (&node->list == l->next_inactive_rotation)
+		l->next_inactive_rotation = l->next_inactive_rotation->prev;
+
+	bpf_lru_list_count_dec(l, node->type);
+
+	node->type = tgt_free_type;
+	list_move(&node->list, free_list);
+}
+
+/* Move nodes from local list to the LRU list */
+static void __bpf_lru_node_move_in(struct bpf_lru_list *l,
+				   struct bpf_lru_node *node,
+				   enum bpf_lru_list_type tgt_type)
+{
+	if (WARN_ON_ONCE(!IS_LOCAL_LIST_TYPE(node->type)) ||
+	    WARN_ON_ONCE(IS_LOCAL_LIST_TYPE(tgt_type)))
+		return;
+
+	bpf_lru_list_count_inc(l, tgt_type);
+	node->type = tgt_type;
+	bpf_lru_node_clear_ref(node);
+	list_move(&node->list, &l->lists[tgt_type]);
+}
+
+/* Move nodes between or within active and inactive list (like
+ * active to inactive, inactive to active or tail of active back to
+ * the head of active).
+ */
+static void __bpf_lru_node_move(struct bpf_lru_list *l,
+				struct bpf_lru_node *node,
+				enum bpf_lru_list_type tgt_type)
+{
+	if (WARN_ON_ONCE(IS_LOCAL_LIST_TYPE(node->type)) ||
+	    WARN_ON_ONCE(IS_LOCAL_LIST_TYPE(tgt_type)))
+		return;
+
+	if (node->type != tgt_type) {
+		bpf_lru_list_count_dec(l, node->type);
+		bpf_lru_list_count_inc(l, tgt_type);
+		node->type = tgt_type;
+	}
+	bpf_lru_node_clear_ref(node);
+
+	/* If the moving node is the next_inactive_rotation candidate,
+	 * move the next_inactive_rotation pointer also.
+	 */
+	if (&node->list == l->next_inactive_rotation)
+		l->next_inactive_rotation = l->next_inactive_rotation->prev;
+
+	list_move(&node->list, &l->lists[tgt_type]);
+}
+
+static bool bpf_lru_list_inactive_low(const struct bpf_lru_list *l)
+{
+	return l->counts[BPF_LRU_LIST_T_INACTIVE] <
+		l->counts[BPF_LRU_LIST_T_ACTIVE];
+}
+
+/* Rotate the active list:
+ * 1. Start from tail
+ * 2. If the node has the ref bit set, it will be rotated
+ *    back to the head of active list with the ref bit cleared.
+ *    Give this node one more chance to survive in the active list.
+ * 3. If the ref bit is not set, move it to the head of the
+ *    inactive list.
+ * 4. It will at most scan nr_scans nodes
+ */
+static void __bpf_lru_list_rotate_active(struct bpf_lru *lru,
+					 struct bpf_lru_list *l)
+{
+	struct list_head *active = &l->lists[BPF_LRU_LIST_T_ACTIVE];
+	struct bpf_lru_node *node, *tmp_node, *first_node;
+	unsigned int i = 0;
+
+	first_node = list_first_entry(active, struct bpf_lru_node, list);
+	list_for_each_entry_safe_reverse(node, tmp_node, active, list) {
+		if (bpf_lru_node_is_ref(node))
+			__bpf_lru_node_move(l, node, BPF_LRU_LIST_T_ACTIVE);
+		else
+			__bpf_lru_node_move(l, node, BPF_LRU_LIST_T_INACTIVE);
+
+		if (++i == lru->nr_scans || node == first_node)
+			break;
+	}
+}
+
+/* Rotate the inactive list.  It starts from the next_inactive_rotation
+ * 1. If the node has ref bit set, it will be moved to the head
+ *    of active list with the ref bit cleared.
+ * 2. If the node does not have ref bit set, it will leave it
+ *    at its current location (i.e. do nothing) so that it can
+ *    be considered during the next inactive_shrink.
+ * 3. It will at most scan nr_scans nodes
+ */
+static void __bpf_lru_list_rotate_inactive(struct bpf_lru *lru,
+					   struct bpf_lru_list *l)
+{
+	struct list_head *inactive = &l->lists[BPF_LRU_LIST_T_INACTIVE];
+	struct list_head *cur, *last, *next = inactive;
+	struct bpf_lru_node *node;
+	unsigned int i = 0;
+
+	if (list_empty(inactive))
+		return;
+
+	last = l->next_inactive_rotation->next;
+	if (last == inactive)
+		last = last->next;
+
+	cur = l->next_inactive_rotation;
+	while (i < lru->nr_scans) {
+		if (cur == inactive) {
+			cur = cur->prev;
+			continue;
+		}
+
+		node = list_entry(cur, struct bpf_lru_node, list);
+		next = cur->prev;
+		if (bpf_lru_node_is_ref(node))
+			__bpf_lru_node_move(l, node, BPF_LRU_LIST_T_ACTIVE);
+		if (cur == last)
+			break;
+		cur = next;
+		i++;
+	}
+
+	l->next_inactive_rotation = next;
+}
+
+/* Shrink the inactive list.  It starts from the tail of the
+ * inactive list and only move the nodes without the ref bit
+ * set to the designated free list.
+ */
+static unsigned int
+__bpf_lru_list_shrink_inactive(struct bpf_lru *lru,
+			       struct bpf_lru_list *l,
+			       unsigned int tgt_nshrink,
+			       struct list_head *free_list,
+			       enum bpf_lru_list_type tgt_free_type)
+{
+	struct list_head *inactive = &l->lists[BPF_LRU_LIST_T_INACTIVE];
+	struct bpf_lru_node *node, *tmp_node;
+	unsigned int nshrinked = 0;
+	unsigned int i = 0;
+
+	list_for_each_entry_safe_reverse(node, tmp_node, inactive, list) {
+		if (bpf_lru_node_is_ref(node)) {
+			__bpf_lru_node_move(l, node, BPF_LRU_LIST_T_ACTIVE);
+		} else if (lru->del_from_htab(lru->del_arg, node)) {
+			__bpf_lru_node_move_to_free(l, node, free_list,
+						    tgt_free_type);
+			if (++nshrinked == tgt_nshrink)
+				break;
+		}
+
+		if (++i == lru->nr_scans)
+			break;
+	}
+
+	return nshrinked;
+}
+
+/* 1. Rotate the active list (if needed)
+ * 2. Always rotate the inactive list
+ */
+static void __bpf_lru_list_rotate(struct bpf_lru *lru, struct bpf_lru_list *l)
+{
+	if (bpf_lru_list_inactive_low(l))
+		__bpf_lru_list_rotate_active(lru, l);
+
+	__bpf_lru_list_rotate_inactive(lru, l);
+}
+
+/* Calls __bpf_lru_list_shrink_inactive() to shrink some
+ * ref-bit-cleared nodes and move them to the designated
+ * free list.
+ *
+ * If it cannot get a free node after calling
+ * __bpf_lru_list_shrink_inactive().  It will just remove
+ * one node from either inactive or active list without
+ * honoring the ref-bit.  It prefers inactive list to active
+ * list in this situation.
+ */
+static unsigned int __bpf_lru_list_shrink(struct bpf_lru *lru,
+					  struct bpf_lru_list *l,
+					  unsigned int tgt_nshrink,
+					  struct list_head *free_list,
+					  enum bpf_lru_list_type tgt_free_type)
+
+{
+	struct bpf_lru_node *node, *tmp_node;
+	struct list_head *force_shrink_list;
+	unsigned int nshrinked;
+
+	nshrinked = __bpf_lru_list_shrink_inactive(lru, l, tgt_nshrink,
+						   free_list, tgt_free_type);
+	if (nshrinked)
+		return nshrinked;
+
+	/* Do a force shrink by ignoring the reference bit */
+	if (!list_empty(&l->lists[BPF_LRU_LIST_T_INACTIVE]))
+		force_shrink_list = &l->lists[BPF_LRU_LIST_T_INACTIVE];
+	else
+		force_shrink_list = &l->lists[BPF_LRU_LIST_T_ACTIVE];
+
+	list_for_each_entry_safe_reverse(node, tmp_node, force_shrink_list,
+					 list) {
+		if (lru->del_from_htab(lru->del_arg, node)) {
+			__bpf_lru_node_move_to_free(l, node, free_list,
+						    tgt_free_type);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+/* Flush the nodes from the local pending list to the LRU list */
+static void __local_list_flush(struct bpf_lru_list *l,
+			       struct bpf_lru_locallist *loc_l)
+{
+	struct bpf_lru_node *node, *tmp_node;
+
+	list_for_each_entry_safe_reverse(node, tmp_node,
+					 local_pending_list(loc_l), list) {
+		if (bpf_lru_node_is_ref(node))
+			__bpf_lru_node_move_in(l, node, BPF_LRU_LIST_T_ACTIVE);
+		else
+			__bpf_lru_node_move_in(l, node,
+					       BPF_LRU_LIST_T_INACTIVE);
+	}
+}
+
+static void bpf_lru_list_push_free(struct bpf_lru_list *l,
+				   struct bpf_lru_node *node)
+{
+	unsigned long flags;
+
+	if (WARN_ON_ONCE(IS_LOCAL_LIST_TYPE(node->type)))
+		return;
+
+	raw_spin_lock_irqsave(&l->lock, flags);
+	__bpf_lru_node_move(l, node, BPF_LRU_LIST_T_FREE);
+	raw_spin_unlock_irqrestore(&l->lock, flags);
+}
+
+static void bpf_lru_list_pop_free_to_local(struct bpf_lru *lru,
+					   struct bpf_lru_locallist *loc_l)
+{
+	struct bpf_lru_list *l = &lru->common_lru.lru_list;
+	struct bpf_lru_node *node, *tmp_node;
+	unsigned int nfree = 0;
+
+	raw_spin_lock(&l->lock);
+
+	__local_list_flush(l, loc_l);
+
+	__bpf_lru_list_rotate(lru, l);
+
+	list_for_each_entry_safe(node, tmp_node, &l->lists[BPF_LRU_LIST_T_FREE],
+				 list) {
+		__bpf_lru_node_move_to_free(l, node, local_free_list(loc_l),
+					    BPF_LRU_LOCAL_LIST_T_FREE);
+		if (++nfree == LOCAL_FREE_TARGET)
+			break;
+	}
+
+	if (nfree < LOCAL_FREE_TARGET)
+		__bpf_lru_list_shrink(lru, l, LOCAL_FREE_TARGET - nfree,
+				      local_free_list(loc_l),
+				      BPF_LRU_LOCAL_LIST_T_FREE);
+
+	raw_spin_unlock(&l->lock);
+}
+
+static void __local_list_add_pending(struct bpf_lru *lru,
+				     struct bpf_lru_locallist *loc_l,
+				     int cpu,
+				     struct bpf_lru_node *node,
+				     u32 hash)
+{
+	*(u32 *)((void *)node + lru->hash_offset) = hash;
+	node->cpu = cpu;
+	node->type = BPF_LRU_LOCAL_LIST_T_PENDING;
+	bpf_lru_node_clear_ref(node);
+	list_add(&node->list, local_pending_list(loc_l));
+}
+
+static struct bpf_lru_node *
+__local_list_pop_free(struct bpf_lru_locallist *loc_l)
+{
+	struct bpf_lru_node *node;
+
+	node = list_first_entry_or_null(local_free_list(loc_l),
+					struct bpf_lru_node,
+					list);
+	if (node)
+		list_del(&node->list);
+
+	return node;
+}
+
+static struct bpf_lru_node *
+__local_list_pop_pending(struct bpf_lru *lru, struct bpf_lru_locallist *loc_l)
+{
+	struct bpf_lru_node *node;
+	bool force = false;
+
+ignore_ref:
+	/* Get from the tail (i.e. older element) of the pending list. */
+	list_for_each_entry_reverse(node, local_pending_list(loc_l),
+				    list) {
+		if ((!bpf_lru_node_is_ref(node) || force) &&
+		    lru->del_from_htab(lru->del_arg, node)) {
+			list_del(&node->list);
+			return node;
+		}
+	}
+
+	if (!force) {
+		force = true;
+		goto ignore_ref;
+	}
+
+	return NULL;
+}
+
+static struct bpf_lru_node *bpf_percpu_lru_pop_free(struct bpf_lru *lru,
+						    u32 hash)
+{
+	struct list_head *free_list;
+	struct bpf_lru_node *node = NULL;
+	struct bpf_lru_list *l;
+	unsigned long flags;
+	int cpu = raw_smp_processor_id();
+
+	l = per_cpu_ptr(lru->percpu_lru, cpu);
+
+	raw_spin_lock_irqsave(&l->lock, flags);
+
+	__bpf_lru_list_rotate(lru, l);
+
+	free_list = &l->lists[BPF_LRU_LIST_T_FREE];
+	if (list_empty(free_list))
+		__bpf_lru_list_shrink(lru, l, PERCPU_FREE_TARGET, free_list,
+				      BPF_LRU_LIST_T_FREE);
+
+	if (!list_empty(free_list)) {
+		node = list_first_entry(free_list, struct bpf_lru_node, list);
+		*(u32 *)((void *)node + lru->hash_offset) = hash;
+		bpf_lru_node_clear_ref(node);
+		__bpf_lru_node_move(l, node, BPF_LRU_LIST_T_INACTIVE);
+	}
+
+	raw_spin_unlock_irqrestore(&l->lock, flags);
+
+	return node;
+}
+
+static struct bpf_lru_node *bpf_common_lru_pop_free(struct bpf_lru *lru,
+						    u32 hash)
+{
+	struct bpf_lru_locallist *loc_l, *steal_loc_l;
+	struct bpf_common_lru *clru = &lru->common_lru;
+	struct bpf_lru_node *node;
+	int steal, first_steal;
+	unsigned long flags;
+	int cpu = raw_smp_processor_id();
+
+	loc_l = per_cpu_ptr(clru->local_list, cpu);
+
+	raw_spin_lock_irqsave(&loc_l->lock, flags);
+
+	node = __local_list_pop_free(loc_l);
+	if (!node) {
+		bpf_lru_list_pop_free_to_local(lru, loc_l);
+		node = __local_list_pop_free(loc_l);
+	}
+
+	if (node)
+		__local_list_add_pending(lru, loc_l, cpu, node, hash);
+
+	raw_spin_unlock_irqrestore(&loc_l->lock, flags);
+
+	if (node)
+		return node;
+
+	/* No free nodes found from the local free list and
+	 * the global LRU list.
+	 *
+	 * Steal from the local free/pending list of the
+	 * current CPU and remote CPU in RR.  It starts
+	 * with the loc_l->next_steal CPU.
+	 */
+
+	first_steal = loc_l->next_steal;
+	steal = first_steal;
+	do {
+		steal_loc_l = per_cpu_ptr(clru->local_list, steal);
+
+		raw_spin_lock_irqsave(&steal_loc_l->lock, flags);
+
+		node = __local_list_pop_free(steal_loc_l);
+		if (!node)
+			node = __local_list_pop_pending(lru, steal_loc_l);
+
+		raw_spin_unlock_irqrestore(&steal_loc_l->lock, flags);
+
+		steal = get_next_cpu(steal);
+	} while (!node && steal != first_steal);
+
+	loc_l->next_steal = steal;
+
+	if (node) {
+		raw_spin_lock_irqsave(&loc_l->lock, flags);
+		__local_list_add_pending(lru, loc_l, cpu, node, hash);
+		raw_spin_unlock_irqrestore(&loc_l->lock, flags);
+	}
+
+	return node;
+}
+
+struct bpf_lru_node *bpf_lru_pop_free(struct bpf_lru *lru, u32 hash)
+{
+	if (lru->percpu)
+		return bpf_percpu_lru_pop_free(lru, hash);
+	else
+		return bpf_common_lru_pop_free(lru, hash);
+}
+
+static void bpf_common_lru_push_free(struct bpf_lru *lru,
+				     struct bpf_lru_node *node)
+{
+	u8 node_type = READ_ONCE(node->type);
+	unsigned long flags;
+
+	if (WARN_ON_ONCE(node_type == BPF_LRU_LIST_T_FREE) ||
+	    WARN_ON_ONCE(node_type == BPF_LRU_LOCAL_LIST_T_FREE))
+		return;
+
+	if (node_type == BPF_LRU_LOCAL_LIST_T_PENDING) {
+		struct bpf_lru_locallist *loc_l;
+
+		loc_l = per_cpu_ptr(lru->common_lru.local_list, node->cpu);
+
+		raw_spin_lock_irqsave(&loc_l->lock, flags);
+
+		if (unlikely(node->type != BPF_LRU_LOCAL_LIST_T_PENDING)) {
+			raw_spin_unlock_irqrestore(&loc_l->lock, flags);
+			goto check_lru_list;
+		}
+
+		node->type = BPF_LRU_LOCAL_LIST_T_FREE;
+		bpf_lru_node_clear_ref(node);
+		list_move(&node->list, local_free_list(loc_l));
+
+		raw_spin_unlock_irqrestore(&loc_l->lock, flags);
+		return;
+	}
+
+check_lru_list:
+	bpf_lru_list_push_free(&lru->common_lru.lru_list, node);
+}
+
+static void bpf_percpu_lru_push_free(struct bpf_lru *lru,
+				     struct bpf_lru_node *node)
+{
+	struct bpf_lru_list *l;
+	unsigned long flags;
+
+	l = per_cpu_ptr(lru->percpu_lru, node->cpu);
+
+	raw_spin_lock_irqsave(&l->lock, flags);
+
+	__bpf_lru_node_move(l, node, BPF_LRU_LIST_T_FREE);
+
+	raw_spin_unlock_irqrestore(&l->lock, flags);
+}
+
+void bpf_lru_push_free(struct bpf_lru *lru, struct bpf_lru_node *node)
+{
+	if (lru->percpu)
+		bpf_percpu_lru_push_free(lru, node);
+	else
+		bpf_common_lru_push_free(lru, node);
+}
+
+static void bpf_common_lru_populate(struct bpf_lru *lru, void *buf,
+				    u32 node_offset, u32 elem_size,
+				    u32 nr_elems)
+{
+	struct bpf_lru_list *l = &lru->common_lru.lru_list;
+	u32 i;
+
+	for (i = 0; i < nr_elems; i++) {
+		struct bpf_lru_node *node;
+
+		node = (struct bpf_lru_node *)(buf + node_offset);
+		node->type = BPF_LRU_LIST_T_FREE;
+		bpf_lru_node_clear_ref(node);
+		list_add(&node->list, &l->lists[BPF_LRU_LIST_T_FREE]);
+		buf += elem_size;
+	}
+}
+
+static void bpf_percpu_lru_populate(struct bpf_lru *lru, void *buf,
+				    u32 node_offset, u32 elem_size,
+				    u32 nr_elems)
+{
+	u32 i, pcpu_entries;
+	int cpu;
+	struct bpf_lru_list *l;
+
+	pcpu_entries = nr_elems / num_possible_cpus();
+
+	i = 0;
+
+	for_each_possible_cpu(cpu) {
+		struct bpf_lru_node *node;
+
+		l = per_cpu_ptr(lru->percpu_lru, cpu);
+again:
+		node = (struct bpf_lru_node *)(buf + node_offset);
+		node->cpu = cpu;
+		node->type = BPF_LRU_LIST_T_FREE;
+		bpf_lru_node_clear_ref(node);
+		list_add(&node->list, &l->lists[BPF_LRU_LIST_T_FREE]);
+		i++;
+		buf += elem_size;
+		if (i == nr_elems)
+			break;
+		if (i % pcpu_entries)
+			goto again;
+	}
+}
+
+void bpf_lru_populate(struct bpf_lru *lru, void *buf, u32 node_offset,
+		      u32 elem_size, u32 nr_elems)
+{
+	if (lru->percpu)
+		bpf_percpu_lru_populate(lru, buf, node_offset, elem_size,
+					nr_elems);
+	else
+		bpf_common_lru_populate(lru, buf, node_offset, elem_size,
+					nr_elems);
+}
+
+static void bpf_lru_locallist_init(struct bpf_lru_locallist *loc_l, int cpu)
+{
+	int i;
+
+	for (i = 0; i < NR_BPF_LRU_LOCAL_LIST_T; i++)
+		INIT_LIST_HEAD(&loc_l->lists[i]);
+
+	loc_l->next_steal = cpu;
+
+	raw_spin_lock_init(&loc_l->lock);
+}
+
+static void bpf_lru_list_init(struct bpf_lru_list *l)
+{
+	int i;
+
+	for (i = 0; i < NR_BPF_LRU_LIST_T; i++)
+		INIT_LIST_HEAD(&l->lists[i]);
+
+	for (i = 0; i < NR_BPF_LRU_LIST_COUNT; i++)
+		l->counts[i] = 0;
+
+	l->next_inactive_rotation = &l->lists[BPF_LRU_LIST_T_INACTIVE];
+
+	raw_spin_lock_init(&l->lock);
+}
+
+int bpf_lru_init(struct bpf_lru *lru, bool percpu, u32 hash_offset,
+		 del_from_htab_func del_from_htab, void *del_arg)
+{
+	int cpu;
+
+	if (percpu) {
+		lru->percpu_lru = alloc_percpu(struct bpf_lru_list);
+		if (!lru->percpu_lru)
+			return -ENOMEM;
+
+		for_each_possible_cpu(cpu) {
+			struct bpf_lru_list *l;
+
+			l = per_cpu_ptr(lru->percpu_lru, cpu);
+			bpf_lru_list_init(l);
+		}
+		lru->nr_scans = PERCPU_NR_SCANS;
+	} else {
+		struct bpf_common_lru *clru = &lru->common_lru;
+
+		clru->local_list = alloc_percpu(struct bpf_lru_locallist);
+		if (!clru->local_list)
+			return -ENOMEM;
+
+		for_each_possible_cpu(cpu) {
+			struct bpf_lru_locallist *loc_l;
+
+			loc_l = per_cpu_ptr(clru->local_list, cpu);
+			bpf_lru_locallist_init(loc_l, cpu);
+		}
+
+		bpf_lru_list_init(&clru->lru_list);
+		lru->nr_scans = LOCAL_NR_SCANS;
+	}
+
+	lru->percpu = percpu;
+	lru->del_from_htab = del_from_htab;
+	lru->del_arg = del_arg;
+	lru->hash_offset = hash_offset;
+
+	return 0;
+}
+
+void bpf_lru_destroy(struct bpf_lru *lru)
+{
+	if (lru->percpu)
+		free_percpu(lru->percpu_lru);
+	else
+		free_percpu(lru->common_lru.local_list);
+}
diff --git a/kernel/bpf/bpf_lru_list.h b/kernel/bpf/bpf_lru_list.h
new file mode 100644
index 000000000..9c12ee453
--- /dev/null
+++ b/kernel/bpf/bpf_lru_list.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2016 Facebook
+ */
+#ifndef __BPF_LRU_LIST_H_
+#define __BPF_LRU_LIST_H_
+
+#include <linux/list.h>
+#include <linux/spinlock_types.h>
+
+#define NR_BPF_LRU_LIST_T	(3)
+#define NR_BPF_LRU_LIST_COUNT	(2)
+#define NR_BPF_LRU_LOCAL_LIST_T (2)
+#define BPF_LOCAL_LIST_T_OFFSET NR_BPF_LRU_LIST_T
+
+enum bpf_lru_list_type {
+	BPF_LRU_LIST_T_ACTIVE,
+	BPF_LRU_LIST_T_INACTIVE,
+	BPF_LRU_LIST_T_FREE,
+	BPF_LRU_LOCAL_LIST_T_FREE,
+	BPF_LRU_LOCAL_LIST_T_PENDING,
+};
+
+struct bpf_lru_node {
+	struct list_head list;
+	u16 cpu;
+	u8 type;
+	u8 ref;
+};
+
+struct bpf_lru_list {
+	struct list_head lists[NR_BPF_LRU_LIST_T];
+	unsigned int counts[NR_BPF_LRU_LIST_COUNT];
+	/* The next inactive list rotation starts from here */
+	struct list_head *next_inactive_rotation;
+
+	raw_spinlock_t lock ____cacheline_aligned_in_smp;
+};
+
+struct bpf_lru_locallist {
+	struct list_head lists[NR_BPF_LRU_LOCAL_LIST_T];
+	u16 next_steal;
+	raw_spinlock_t lock;
+};
+
+struct bpf_common_lru {
+	struct bpf_lru_list lru_list;
+	struct bpf_lru_locallist __percpu *local_list;
+};
+
+typedef bool (*del_from_htab_func)(void *arg, struct bpf_lru_node *node);
+
+struct bpf_lru {
+	union {
+		struct bpf_common_lru common_lru;
+		struct bpf_lru_list __percpu *percpu_lru;
+	};
+	del_from_htab_func del_from_htab;
+	void *del_arg;
+	unsigned int hash_offset;
+	unsigned int nr_scans;
+	bool percpu;
+};
+
+static inline void bpf_lru_node_set_ref(struct bpf_lru_node *node)
+{
+	if (!READ_ONCE(node->ref))
+		WRITE_ONCE(node->ref, 1);
+}
+
+int bpf_lru_init(struct bpf_lru *lru, bool percpu, u32 hash_offset,
+		 del_from_htab_func del_from_htab, void *delete_arg);
+void bpf_lru_populate(struct bpf_lru *lru, void *buf, u32 node_offset,
+		      u32 elem_size, u32 nr_elems);
+void bpf_lru_destroy(struct bpf_lru *lru);
+struct bpf_lru_node *bpf_lru_pop_free(struct bpf_lru *lru, u32 hash);
+void bpf_lru_push_free(struct bpf_lru *lru, struct bpf_lru_node *node);
+void bpf_lru_promote(struct bpf_lru *lru, struct bpf_lru_node *node);
+
+#endif
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
new file mode 100644
index 000000000..56cc5a915
--- /dev/null
+++ b/kernel/bpf/bpf_lsm.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2020 Google LLC.
+ */
+
+#include <linux/filter.h>
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/lsm_hooks.h>
+#include <linux/bpf_lsm.h>
+#include <linux/kallsyms.h>
+#include <linux/bpf_verifier.h>
+#include <net/bpf_sk_storage.h>
+#include <linux/bpf_local_storage.h>
+#include <linux/btf_ids.h>
+
+/* For every LSM hook that allows attachment of BPF programs, declare a nop
+ * function where a BPF program can be attached.
+ */
+#define LSM_HOOK(RET, DEFAULT, NAME, ...)	\
+noinline RET bpf_lsm_##NAME(__VA_ARGS__)	\
+{						\
+	return DEFAULT;				\
+}
+
+#include <linux/lsm_hook_defs.h>
+#undef LSM_HOOK
+
+#define LSM_HOOK(RET, DEFAULT, NAME, ...) BTF_ID(func, bpf_lsm_##NAME)
+BTF_SET_START(bpf_lsm_hooks)
+#include <linux/lsm_hook_defs.h>
+#undef LSM_HOOK
+BTF_SET_END(bpf_lsm_hooks)
+
+int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog,
+			const struct bpf_prog *prog)
+{
+	if (!prog->gpl_compatible) {
+		bpf_log(vlog,
+			"LSM programs must have a GPL compatible license\n");
+		return -EINVAL;
+	}
+
+	if (!btf_id_set_contains(&bpf_lsm_hooks, prog->aux->attach_btf_id)) {
+		bpf_log(vlog, "attach_btf_id %u points to wrong type name %s\n",
+			prog->aux->attach_btf_id, prog->aux->attach_func_name);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct bpf_func_proto *
+bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	switch (func_id) {
+	case BPF_FUNC_inode_storage_get:
+		return &bpf_inode_storage_get_proto;
+	case BPF_FUNC_inode_storage_delete:
+		return &bpf_inode_storage_delete_proto;
+	case BPF_FUNC_sk_storage_get:
+		return &bpf_sk_storage_get_proto;
+	case BPF_FUNC_sk_storage_delete:
+		return &bpf_sk_storage_delete_proto;
+	default:
+		return tracing_prog_func_proto(func_id, prog);
+	}
+}
+
+const struct bpf_prog_ops lsm_prog_ops = {
+};
+
+const struct bpf_verifier_ops lsm_verifier_ops = {
+	.get_func_proto = bpf_lsm_func_proto,
+	.is_valid_access = btf_ctx_access,
+};
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
new file mode 100644
index 000000000..ac283f9b2
--- /dev/null
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -0,0 +1,653 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2019 Facebook */
+
+#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
+#include <linux/btf.h>
+#include <linux/filter.h>
+#include <linux/slab.h>
+#include <linux/numa.h>
+#include <linux/seq_file.h>
+#include <linux/refcount.h>
+#include <linux/mutex.h>
+
+enum bpf_struct_ops_state {
+	BPF_STRUCT_OPS_STATE_INIT,
+	BPF_STRUCT_OPS_STATE_INUSE,
+	BPF_STRUCT_OPS_STATE_TOBEFREE,
+};
+
+#define BPF_STRUCT_OPS_COMMON_VALUE			\
+	refcount_t refcnt;				\
+	enum bpf_struct_ops_state state
+
+struct bpf_struct_ops_value {
+	BPF_STRUCT_OPS_COMMON_VALUE;
+	char data[] ____cacheline_aligned_in_smp;
+};
+
+struct bpf_struct_ops_map {
+	struct bpf_map map;
+	const struct bpf_struct_ops *st_ops;
+	/* protect map_update */
+	struct mutex lock;
+	/* progs has all the bpf_prog that is populated
+	 * to the func ptr of the kernel's struct
+	 * (in kvalue.data).
+	 */
+	struct bpf_prog **progs;
+	/* image is a page that has all the trampolines
+	 * that stores the func args before calling the bpf_prog.
+	 * A PAGE_SIZE "image" is enough to store all trampoline for
+	 * "progs[]".
+	 */
+	void *image;
+	/* uvalue->data stores the kernel struct
+	 * (e.g. tcp_congestion_ops) that is more useful
+	 * to userspace than the kvalue.  For example,
+	 * the bpf_prog's id is stored instead of the kernel
+	 * address of a func ptr.
+	 */
+	struct bpf_struct_ops_value *uvalue;
+	/* kvalue.data stores the actual kernel's struct
+	 * (e.g. tcp_congestion_ops) that will be
+	 * registered to the kernel subsystem.
+	 */
+	struct bpf_struct_ops_value kvalue;
+};
+
+#define VALUE_PREFIX "bpf_struct_ops_"
+#define VALUE_PREFIX_LEN (sizeof(VALUE_PREFIX) - 1)
+
+/* bpf_struct_ops_##_name (e.g. bpf_struct_ops_tcp_congestion_ops) is
+ * the map's value exposed to the userspace and its btf-type-id is
+ * stored at the map->btf_vmlinux_value_type_id.
+ *
+ */
+#define BPF_STRUCT_OPS_TYPE(_name)				\
+extern struct bpf_struct_ops bpf_##_name;			\
+								\
+struct bpf_struct_ops_##_name {						\
+	BPF_STRUCT_OPS_COMMON_VALUE;				\
+	struct _name data ____cacheline_aligned_in_smp;		\
+};
+#include "bpf_struct_ops_types.h"
+#undef BPF_STRUCT_OPS_TYPE
+
+enum {
+#define BPF_STRUCT_OPS_TYPE(_name) BPF_STRUCT_OPS_TYPE_##_name,
+#include "bpf_struct_ops_types.h"
+#undef BPF_STRUCT_OPS_TYPE
+	__NR_BPF_STRUCT_OPS_TYPE,
+};
+
+static struct bpf_struct_ops * const bpf_struct_ops[] = {
+#define BPF_STRUCT_OPS_TYPE(_name)				\
+	[BPF_STRUCT_OPS_TYPE_##_name] = &bpf_##_name,
+#include "bpf_struct_ops_types.h"
+#undef BPF_STRUCT_OPS_TYPE
+};
+
+const struct bpf_verifier_ops bpf_struct_ops_verifier_ops = {
+};
+
+const struct bpf_prog_ops bpf_struct_ops_prog_ops = {
+};
+
+static const struct btf_type *module_type;
+
+void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
+{
+	s32 type_id, value_id, module_id;
+	const struct btf_member *member;
+	struct bpf_struct_ops *st_ops;
+	const struct btf_type *t;
+	char value_name[128];
+	const char *mname;
+	u32 i, j;
+
+	/* Ensure BTF type is emitted for "struct bpf_struct_ops_##_name" */
+#define BPF_STRUCT_OPS_TYPE(_name) BTF_TYPE_EMIT(struct bpf_struct_ops_##_name);
+#include "bpf_struct_ops_types.h"
+#undef BPF_STRUCT_OPS_TYPE
+
+	module_id = btf_find_by_name_kind(btf, "module", BTF_KIND_STRUCT);
+	if (module_id < 0) {
+		pr_warn("Cannot find struct module in btf_vmlinux\n");
+		return;
+	}
+	module_type = btf_type_by_id(btf, module_id);
+
+	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
+		st_ops = bpf_struct_ops[i];
+
+		if (strlen(st_ops->name) + VALUE_PREFIX_LEN >=
+		    sizeof(value_name)) {
+			pr_warn("struct_ops name %s is too long\n",
+				st_ops->name);
+			continue;
+		}
+		sprintf(value_name, "%s%s", VALUE_PREFIX, st_ops->name);
+
+		value_id = btf_find_by_name_kind(btf, value_name,
+						 BTF_KIND_STRUCT);
+		if (value_id < 0) {
+			pr_warn("Cannot find struct %s in btf_vmlinux\n",
+				value_name);
+			continue;
+		}
+
+		type_id = btf_find_by_name_kind(btf, st_ops->name,
+						BTF_KIND_STRUCT);
+		if (type_id < 0) {
+			pr_warn("Cannot find struct %s in btf_vmlinux\n",
+				st_ops->name);
+			continue;
+		}
+		t = btf_type_by_id(btf, type_id);
+		if (btf_type_vlen(t) > BPF_STRUCT_OPS_MAX_NR_MEMBERS) {
+			pr_warn("Cannot support #%u members in struct %s\n",
+				btf_type_vlen(t), st_ops->name);
+			continue;
+		}
+
+		for_each_member(j, t, member) {
+			const struct btf_type *func_proto;
+
+			mname = btf_name_by_offset(btf, member->name_off);
+			if (!*mname) {
+				pr_warn("anon member in struct %s is not supported\n",
+					st_ops->name);
+				break;
+			}
+
+			if (btf_member_bitfield_size(t, member)) {
+				pr_warn("bit field member %s in struct %s is not supported\n",
+					mname, st_ops->name);
+				break;
+			}
+
+			func_proto = btf_type_resolve_func_ptr(btf,
+							       member->type,
+							       NULL);
+			if (func_proto &&
+			    btf_distill_func_proto(log, btf,
+						   func_proto, mname,
+						   &st_ops->func_models[j])) {
+				pr_warn("Error in parsing func ptr %s in struct %s\n",
+					mname, st_ops->name);
+				break;
+			}
+		}
+
+		if (j == btf_type_vlen(t)) {
+			if (st_ops->init(btf)) {
+				pr_warn("Error in init bpf_struct_ops %s\n",
+					st_ops->name);
+			} else {
+				st_ops->type_id = type_id;
+				st_ops->type = t;
+				st_ops->value_id = value_id;
+				st_ops->value_type = btf_type_by_id(btf,
+								    value_id);
+			}
+		}
+	}
+}
+
+extern struct btf *btf_vmlinux;
+
+static const struct bpf_struct_ops *
+bpf_struct_ops_find_value(u32 value_id)
+{
+	unsigned int i;
+
+	if (!value_id || !btf_vmlinux)
+		return NULL;
+
+	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
+		if (bpf_struct_ops[i]->value_id == value_id)
+			return bpf_struct_ops[i];
+	}
+
+	return NULL;
+}
+
+const struct bpf_struct_ops *bpf_struct_ops_find(u32 type_id)
+{
+	unsigned int i;
+
+	if (!type_id || !btf_vmlinux)
+		return NULL;
+
+	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
+		if (bpf_struct_ops[i]->type_id == type_id)
+			return bpf_struct_ops[i];
+	}
+
+	return NULL;
+}
+
+static int bpf_struct_ops_map_get_next_key(struct bpf_map *map, void *key,
+					   void *next_key)
+{
+	if (key && *(u32 *)key == 0)
+		return -ENOENT;
+
+	*(u32 *)next_key = 0;
+	return 0;
+}
+
+int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key,
+				       void *value)
+{
+	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
+	struct bpf_struct_ops_value *uvalue, *kvalue;
+	enum bpf_struct_ops_state state;
+
+	if (unlikely(*(u32 *)key != 0))
+		return -ENOENT;
+
+	kvalue = &st_map->kvalue;
+	/* Pair with smp_store_release() during map_update */
+	state = smp_load_acquire(&kvalue->state);
+	if (state == BPF_STRUCT_OPS_STATE_INIT) {
+		memset(value, 0, map->value_size);
+		return 0;
+	}
+
+	/* No lock is needed.  state and refcnt do not need
+	 * to be updated together under atomic context.
+	 */
+	uvalue = (struct bpf_struct_ops_value *)value;
+	memcpy(uvalue, st_map->uvalue, map->value_size);
+	uvalue->state = state;
+	refcount_set(&uvalue->refcnt, refcount_read(&kvalue->refcnt));
+
+	return 0;
+}
+
+static void *bpf_struct_ops_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static void bpf_struct_ops_map_put_progs(struct bpf_struct_ops_map *st_map)
+{
+	const struct btf_type *t = st_map->st_ops->type;
+	u32 i;
+
+	for (i = 0; i < btf_type_vlen(t); i++) {
+		if (st_map->progs[i]) {
+			bpf_prog_put(st_map->progs[i]);
+			st_map->progs[i] = NULL;
+		}
+	}
+}
+
+static int check_zero_holes(const struct btf_type *t, void *data)
+{
+	const struct btf_member *member;
+	u32 i, moff, msize, prev_mend = 0;
+	const struct btf_type *mtype;
+
+	for_each_member(i, t, member) {
+		moff = btf_member_bit_offset(t, member) / 8;
+		if (moff > prev_mend &&
+		    memchr_inv(data + prev_mend, 0, moff - prev_mend))
+			return -EINVAL;
+
+		mtype = btf_type_by_id(btf_vmlinux, member->type);
+		mtype = btf_resolve_size(btf_vmlinux, mtype, &msize);
+		if (IS_ERR(mtype))
+			return PTR_ERR(mtype);
+		prev_mend = moff + msize;
+	}
+
+	if (t->size > prev_mend &&
+	    memchr_inv(data + prev_mend, 0, t->size - prev_mend))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
+					  void *value, u64 flags)
+{
+	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
+	const struct bpf_struct_ops *st_ops = st_map->st_ops;
+	struct bpf_struct_ops_value *uvalue, *kvalue;
+	const struct btf_member *member;
+	const struct btf_type *t = st_ops->type;
+	struct bpf_tramp_progs *tprogs = NULL;
+	void *udata, *kdata;
+	int prog_fd, err = 0;
+	void *image;
+	u32 i;
+
+	if (flags)
+		return -EINVAL;
+
+	if (*(u32 *)key != 0)
+		return -E2BIG;
+
+	err = check_zero_holes(st_ops->value_type, value);
+	if (err)
+		return err;
+
+	uvalue = (struct bpf_struct_ops_value *)value;
+	err = check_zero_holes(t, uvalue->data);
+	if (err)
+		return err;
+
+	if (uvalue->state || refcount_read(&uvalue->refcnt))
+		return -EINVAL;
+
+	tprogs = kcalloc(BPF_TRAMP_MAX, sizeof(*tprogs), GFP_KERNEL);
+	if (!tprogs)
+		return -ENOMEM;
+
+	uvalue = (struct bpf_struct_ops_value *)st_map->uvalue;
+	kvalue = (struct bpf_struct_ops_value *)&st_map->kvalue;
+
+	mutex_lock(&st_map->lock);
+
+	if (kvalue->state != BPF_STRUCT_OPS_STATE_INIT) {
+		err = -EBUSY;
+		goto unlock;
+	}
+
+	memcpy(uvalue, value, map->value_size);
+
+	udata = &uvalue->data;
+	kdata = &kvalue->data;
+	image = st_map->image;
+
+	for_each_member(i, t, member) {
+		const struct btf_type *mtype, *ptype;
+		struct bpf_prog *prog;
+		u32 moff;
+		u32 flags;
+
+		moff = btf_member_bit_offset(t, member) / 8;
+		ptype = btf_type_resolve_ptr(btf_vmlinux, member->type, NULL);
+		if (ptype == module_type) {
+			if (*(void **)(udata + moff))
+				goto reset_unlock;
+			*(void **)(kdata + moff) = BPF_MODULE_OWNER;
+			continue;
+		}
+
+		err = st_ops->init_member(t, member, kdata, udata);
+		if (err < 0)
+			goto reset_unlock;
+
+		/* The ->init_member() has handled this member */
+		if (err > 0)
+			continue;
+
+		/* If st_ops->init_member does not handle it,
+		 * we will only handle func ptrs and zero-ed members
+		 * here.  Reject everything else.
+		 */
+
+		/* All non func ptr member must be 0 */
+		if (!ptype || !btf_type_is_func_proto(ptype)) {
+			u32 msize;
+
+			mtype = btf_type_by_id(btf_vmlinux, member->type);
+			mtype = btf_resolve_size(btf_vmlinux, mtype, &msize);
+			if (IS_ERR(mtype)) {
+				err = PTR_ERR(mtype);
+				goto reset_unlock;
+			}
+
+			if (memchr_inv(udata + moff, 0, msize)) {
+				err = -EINVAL;
+				goto reset_unlock;
+			}
+
+			continue;
+		}
+
+		prog_fd = (int)(*(unsigned long *)(udata + moff));
+		/* Similar check as the attr->attach_prog_fd */
+		if (!prog_fd)
+			continue;
+
+		prog = bpf_prog_get(prog_fd);
+		if (IS_ERR(prog)) {
+			err = PTR_ERR(prog);
+			goto reset_unlock;
+		}
+		st_map->progs[i] = prog;
+
+		if (prog->type != BPF_PROG_TYPE_STRUCT_OPS ||
+		    prog->aux->attach_btf_id != st_ops->type_id ||
+		    prog->expected_attach_type != i) {
+			err = -EINVAL;
+			goto reset_unlock;
+		}
+
+		tprogs[BPF_TRAMP_FENTRY].progs[0] = prog;
+		tprogs[BPF_TRAMP_FENTRY].nr_progs = 1;
+		flags = st_ops->func_models[i].ret_size > 0 ?
+			BPF_TRAMP_F_RET_FENTRY_RET : 0;
+		err = arch_prepare_bpf_trampoline(NULL, image,
+						  st_map->image + PAGE_SIZE,
+						  &st_ops->func_models[i],
+						  flags, tprogs, NULL);
+		if (err < 0)
+			goto reset_unlock;
+
+		*(void **)(kdata + moff) = image;
+		image += err;
+
+		/* put prog_id to udata */
+		*(unsigned long *)(udata + moff) = prog->aux->id;
+	}
+
+	refcount_set(&kvalue->refcnt, 1);
+	bpf_map_inc(map);
+
+	set_memory_ro((long)st_map->image, 1);
+	set_memory_x((long)st_map->image, 1);
+	err = st_ops->reg(kdata);
+	if (likely(!err)) {
+		/* Pair with smp_load_acquire() during lookup_elem().
+		 * It ensures the above udata updates (e.g. prog->aux->id)
+		 * can be seen once BPF_STRUCT_OPS_STATE_INUSE is set.
+		 */
+		smp_store_release(&kvalue->state, BPF_STRUCT_OPS_STATE_INUSE);
+		goto unlock;
+	}
+
+	/* Error during st_ops->reg().  It is very unlikely since
+	 * the above init_member() should have caught it earlier
+	 * before reg().  The only possibility is if there was a race
+	 * in registering the struct_ops (under the same name) to
+	 * a sub-system through different struct_ops's maps.
+	 */
+	set_memory_nx((long)st_map->image, 1);
+	set_memory_rw((long)st_map->image, 1);
+	bpf_map_put(map);
+
+reset_unlock:
+	bpf_struct_ops_map_put_progs(st_map);
+	memset(uvalue, 0, map->value_size);
+	memset(kvalue, 0, map->value_size);
+unlock:
+	kfree(tprogs);
+	mutex_unlock(&st_map->lock);
+	return err;
+}
+
+static int bpf_struct_ops_map_delete_elem(struct bpf_map *map, void *key)
+{
+	enum bpf_struct_ops_state prev_state;
+	struct bpf_struct_ops_map *st_map;
+
+	st_map = (struct bpf_struct_ops_map *)map;
+	prev_state = cmpxchg(&st_map->kvalue.state,
+			     BPF_STRUCT_OPS_STATE_INUSE,
+			     BPF_STRUCT_OPS_STATE_TOBEFREE);
+	switch (prev_state) {
+	case BPF_STRUCT_OPS_STATE_INUSE:
+		st_map->st_ops->unreg(&st_map->kvalue.data);
+		if (refcount_dec_and_test(&st_map->kvalue.refcnt))
+			bpf_map_put(map);
+		return 0;
+	case BPF_STRUCT_OPS_STATE_TOBEFREE:
+		return -EINPROGRESS;
+	case BPF_STRUCT_OPS_STATE_INIT:
+		return -ENOENT;
+	default:
+		WARN_ON_ONCE(1);
+		/* Should never happen.  Treat it as not found. */
+		return -ENOENT;
+	}
+}
+
+static void bpf_struct_ops_map_seq_show_elem(struct bpf_map *map, void *key,
+					     struct seq_file *m)
+{
+	void *value;
+	int err;
+
+	value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
+	if (!value)
+		return;
+
+	err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
+	if (!err) {
+		btf_type_seq_show(btf_vmlinux, map->btf_vmlinux_value_type_id,
+				  value, m);
+		seq_puts(m, "\n");
+	}
+
+	kfree(value);
+}
+
+static void bpf_struct_ops_map_free(struct bpf_map *map)
+{
+	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
+
+	if (st_map->progs)
+		bpf_struct_ops_map_put_progs(st_map);
+	bpf_map_area_free(st_map->progs);
+	bpf_jit_free_exec(st_map->image);
+	bpf_map_area_free(st_map->uvalue);
+	bpf_map_area_free(st_map);
+}
+
+static int bpf_struct_ops_map_alloc_check(union bpf_attr *attr)
+{
+	if (attr->key_size != sizeof(unsigned int) || attr->max_entries != 1 ||
+	    attr->map_flags || !attr->btf_vmlinux_value_type_id)
+		return -EINVAL;
+	return 0;
+}
+
+static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
+{
+	const struct bpf_struct_ops *st_ops;
+	size_t map_total_size, st_map_size;
+	struct bpf_struct_ops_map *st_map;
+	const struct btf_type *t, *vt;
+	struct bpf_map_memory mem;
+	struct bpf_map *map;
+	int err;
+
+	if (!bpf_capable())
+		return ERR_PTR(-EPERM);
+
+	st_ops = bpf_struct_ops_find_value(attr->btf_vmlinux_value_type_id);
+	if (!st_ops)
+		return ERR_PTR(-ENOTSUPP);
+
+	vt = st_ops->value_type;
+	if (attr->value_size != vt->size)
+		return ERR_PTR(-EINVAL);
+
+	t = st_ops->type;
+
+	st_map_size = sizeof(*st_map) +
+		/* kvalue stores the
+		 * struct bpf_struct_ops_tcp_congestions_ops
+		 */
+		(vt->size - sizeof(struct bpf_struct_ops_value));
+	map_total_size = st_map_size +
+		/* uvalue */
+		sizeof(vt->size) +
+		/* struct bpf_progs **progs */
+		 btf_type_vlen(t) * sizeof(struct bpf_prog *);
+	err = bpf_map_charge_init(&mem, map_total_size);
+	if (err < 0)
+		return ERR_PTR(err);
+
+	st_map = bpf_map_area_alloc(st_map_size, NUMA_NO_NODE);
+	if (!st_map) {
+		bpf_map_charge_finish(&mem);
+		return ERR_PTR(-ENOMEM);
+	}
+	st_map->st_ops = st_ops;
+	map = &st_map->map;
+
+	st_map->uvalue = bpf_map_area_alloc(vt->size, NUMA_NO_NODE);
+	st_map->progs =
+		bpf_map_area_alloc(btf_type_vlen(t) * sizeof(struct bpf_prog *),
+				   NUMA_NO_NODE);
+	st_map->image = bpf_jit_alloc_exec(PAGE_SIZE);
+	if (!st_map->uvalue || !st_map->progs || !st_map->image) {
+		bpf_struct_ops_map_free(map);
+		bpf_map_charge_finish(&mem);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	mutex_init(&st_map->lock);
+	set_vm_flush_reset_perms(st_map->image);
+	bpf_map_init_from_attr(map, attr);
+	bpf_map_charge_move(&map->memory, &mem);
+
+	return map;
+}
+
+static int bpf_struct_ops_map_btf_id;
+const struct bpf_map_ops bpf_struct_ops_map_ops = {
+	.map_alloc_check = bpf_struct_ops_map_alloc_check,
+	.map_alloc = bpf_struct_ops_map_alloc,
+	.map_free = bpf_struct_ops_map_free,
+	.map_get_next_key = bpf_struct_ops_map_get_next_key,
+	.map_lookup_elem = bpf_struct_ops_map_lookup_elem,
+	.map_delete_elem = bpf_struct_ops_map_delete_elem,
+	.map_update_elem = bpf_struct_ops_map_update_elem,
+	.map_seq_show_elem = bpf_struct_ops_map_seq_show_elem,
+	.map_btf_name = "bpf_struct_ops_map",
+	.map_btf_id = &bpf_struct_ops_map_btf_id,
+};
+
+/* "const void *" because some subsystem is
+ * passing a const (e.g. const struct tcp_congestion_ops *)
+ */
+bool bpf_struct_ops_get(const void *kdata)
+{
+	struct bpf_struct_ops_value *kvalue;
+
+	kvalue = container_of(kdata, struct bpf_struct_ops_value, data);
+
+	return refcount_inc_not_zero(&kvalue->refcnt);
+}
+
+void bpf_struct_ops_put(const void *kdata)
+{
+	struct bpf_struct_ops_value *kvalue;
+
+	kvalue = container_of(kdata, struct bpf_struct_ops_value, data);
+	if (refcount_dec_and_test(&kvalue->refcnt)) {
+		struct bpf_struct_ops_map *st_map;
+
+		st_map = container_of(kvalue, struct bpf_struct_ops_map,
+				      kvalue);
+		bpf_map_put(&st_map->map);
+	}
+}
diff --git a/kernel/bpf/bpf_struct_ops_types.h b/kernel/bpf/bpf_struct_ops_types.h
new file mode 100644
index 000000000..066d83ea1
--- /dev/null
+++ b/kernel/bpf/bpf_struct_ops_types.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* internal file - do not include directly */
+
+#ifdef CONFIG_BPF_JIT
+#ifdef CONFIG_INET
+#include <net/tcp.h>
+BPF_STRUCT_OPS_TYPE(tcp_congestion_ops)
+#endif
+#endif
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
new file mode 100644
index 000000000..06c028bdb
--- /dev/null
+++ b/kernel/bpf/btf.c
@@ -0,0 +1,5572 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018 Facebook */
+
+#include <uapi/linux/btf.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
+#include <uapi/linux/types.h>
+#include <linux/seq_file.h>
+#include <linux/compiler.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/anon_inodes.h>
+#include <linux/file.h>
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+#include <linux/idr.h>
+#include <linux/sort.h>
+#include <linux/bpf_verifier.h>
+#include <linux/btf.h>
+#include <linux/btf_ids.h>
+#include <linux/skmsg.h>
+#include <linux/perf_event.h>
+#include <linux/bsearch.h>
+#include <linux/btf_ids.h>
+#include <net/sock.h>
+
+/* BTF (BPF Type Format) is the meta data format which describes
+ * the data types of BPF program/map.  Hence, it basically focus
+ * on the C programming language which the modern BPF is primary
+ * using.
+ *
+ * ELF Section:
+ * ~~~~~~~~~~~
+ * The BTF data is stored under the ".BTF" ELF section
+ *
+ * struct btf_type:
+ * ~~~~~~~~~~~~~~~
+ * Each 'struct btf_type' object describes a C data type.
+ * Depending on the type it is describing, a 'struct btf_type'
+ * object may be followed by more data.  F.e.
+ * To describe an array, 'struct btf_type' is followed by
+ * 'struct btf_array'.
+ *
+ * 'struct btf_type' and any extra data following it are
+ * 4 bytes aligned.
+ *
+ * Type section:
+ * ~~~~~~~~~~~~~
+ * The BTF type section contains a list of 'struct btf_type' objects.
+ * Each one describes a C type.  Recall from the above section
+ * that a 'struct btf_type' object could be immediately followed by extra
+ * data in order to desribe some particular C types.
+ *
+ * type_id:
+ * ~~~~~~~
+ * Each btf_type object is identified by a type_id.  The type_id
+ * is implicitly implied by the location of the btf_type object in
+ * the BTF type section.  The first one has type_id 1.  The second
+ * one has type_id 2...etc.  Hence, an earlier btf_type has
+ * a smaller type_id.
+ *
+ * A btf_type object may refer to another btf_type object by using
+ * type_id (i.e. the "type" in the "struct btf_type").
+ *
+ * NOTE that we cannot assume any reference-order.
+ * A btf_type object can refer to an earlier btf_type object
+ * but it can also refer to a later btf_type object.
+ *
+ * For example, to describe "const void *".  A btf_type
+ * object describing "const" may refer to another btf_type
+ * object describing "void *".  This type-reference is done
+ * by specifying type_id:
+ *
+ * [1] CONST (anon) type_id=2
+ * [2] PTR (anon) type_id=0
+ *
+ * The above is the btf_verifier debug log:
+ *   - Each line started with "[?]" is a btf_type object
+ *   - [?] is the type_id of the btf_type object.
+ *   - CONST/PTR is the BTF_KIND_XXX
+ *   - "(anon)" is the name of the type.  It just
+ *     happens that CONST and PTR has no name.
+ *   - type_id=XXX is the 'u32 type' in btf_type
+ *
+ * NOTE: "void" has type_id 0
+ *
+ * String section:
+ * ~~~~~~~~~~~~~~
+ * The BTF string section contains the names used by the type section.
+ * Each string is referred by an "offset" from the beginning of the
+ * string section.
+ *
+ * Each string is '\0' terminated.
+ *
+ * The first character in the string section must be '\0'
+ * which is used to mean 'anonymous'. Some btf_type may not
+ * have a name.
+ */
+
+/* BTF verification:
+ *
+ * To verify BTF data, two passes are needed.
+ *
+ * Pass #1
+ * ~~~~~~~
+ * The first pass is to collect all btf_type objects to
+ * an array: "btf->types".
+ *
+ * Depending on the C type that a btf_type is describing,
+ * a btf_type may be followed by extra data.  We don't know
+ * how many btf_type is there, and more importantly we don't
+ * know where each btf_type is located in the type section.
+ *
+ * Without knowing the location of each type_id, most verifications
+ * cannot be done.  e.g. an earlier btf_type may refer to a later
+ * btf_type (recall the "const void *" above), so we cannot
+ * check this type-reference in the first pass.
+ *
+ * In the first pass, it still does some verifications (e.g.
+ * checking the name is a valid offset to the string section).
+ *
+ * Pass #2
+ * ~~~~~~~
+ * The main focus is to resolve a btf_type that is referring
+ * to another type.
+ *
+ * We have to ensure the referring type:
+ * 1) does exist in the BTF (i.e. in btf->types[])
+ * 2) does not cause a loop:
+ *	struct A {
+ *		struct B b;
+ *	};
+ *
+ *	struct B {
+ *		struct A a;
+ *	};
+ *
+ * btf_type_needs_resolve() decides if a btf_type needs
+ * to be resolved.
+ *
+ * The needs_resolve type implements the "resolve()" ops which
+ * essentially does a DFS and detects backedge.
+ *
+ * During resolve (or DFS), different C types have different
+ * "RESOLVED" conditions.
+ *
+ * When resolving a BTF_KIND_STRUCT, we need to resolve all its
+ * members because a member is always referring to another
+ * type.  A struct's member can be treated as "RESOLVED" if
+ * it is referring to a BTF_KIND_PTR.  Otherwise, the
+ * following valid C struct would be rejected:
+ *
+ *	struct A {
+ *		int m;
+ *		struct A *a;
+ *	};
+ *
+ * When resolving a BTF_KIND_PTR, it needs to keep resolving if
+ * it is referring to another BTF_KIND_PTR.  Otherwise, we cannot
+ * detect a pointer loop, e.g.:
+ * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
+ *                        ^                                         |
+ *                        +-----------------------------------------+
+ *
+ */
+
+#define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2)
+#define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
+#define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
+#define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
+#define BITS_ROUNDUP_BYTES(bits) \
+	(BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
+
+#define BTF_INFO_MASK 0x8f00ffff
+#define BTF_INT_MASK 0x0fffffff
+#define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE)
+#define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET)
+
+/* 16MB for 64k structs and each has 16 members and
+ * a few MB spaces for the string section.
+ * The hard limit is S32_MAX.
+ */
+#define BTF_MAX_SIZE (16 * 1024 * 1024)
+
+#define for_each_member_from(i, from, struct_type, member)		\
+	for (i = from, member = btf_type_member(struct_type) + from;	\
+	     i < btf_type_vlen(struct_type);				\
+	     i++, member++)
+
+#define for_each_vsi_from(i, from, struct_type, member)				\
+	for (i = from, member = btf_type_var_secinfo(struct_type) + from;	\
+	     i < btf_type_vlen(struct_type);					\
+	     i++, member++)
+
+DEFINE_IDR(btf_idr);
+DEFINE_SPINLOCK(btf_idr_lock);
+
+struct btf {
+	void *data;
+	struct btf_type **types;
+	u32 *resolved_ids;
+	u32 *resolved_sizes;
+	const char *strings;
+	void *nohdr_data;
+	struct btf_header hdr;
+	u32 nr_types;
+	u32 types_size;
+	u32 data_size;
+	refcount_t refcnt;
+	u32 id;
+	struct rcu_head rcu;
+};
+
+enum verifier_phase {
+	CHECK_META,
+	CHECK_TYPE,
+};
+
+struct resolve_vertex {
+	const struct btf_type *t;
+	u32 type_id;
+	u16 next_member;
+};
+
+enum visit_state {
+	NOT_VISITED,
+	VISITED,
+	RESOLVED,
+};
+
+enum resolve_mode {
+	RESOLVE_TBD,	/* To Be Determined */
+	RESOLVE_PTR,	/* Resolving for Pointer */
+	RESOLVE_STRUCT_OR_ARRAY,	/* Resolving for struct/union
+					 * or array
+					 */
+};
+
+#define MAX_RESOLVE_DEPTH 32
+
+struct btf_sec_info {
+	u32 off;
+	u32 len;
+};
+
+struct btf_verifier_env {
+	struct btf *btf;
+	u8 *visit_states;
+	struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
+	struct bpf_verifier_log log;
+	u32 log_type_id;
+	u32 top_stack;
+	enum verifier_phase phase;
+	enum resolve_mode resolve_mode;
+};
+
+static const char * const btf_kind_str[NR_BTF_KINDS] = {
+	[BTF_KIND_UNKN]		= "UNKNOWN",
+	[BTF_KIND_INT]		= "INT",
+	[BTF_KIND_PTR]		= "PTR",
+	[BTF_KIND_ARRAY]	= "ARRAY",
+	[BTF_KIND_STRUCT]	= "STRUCT",
+	[BTF_KIND_UNION]	= "UNION",
+	[BTF_KIND_ENUM]		= "ENUM",
+	[BTF_KIND_FWD]		= "FWD",
+	[BTF_KIND_TYPEDEF]	= "TYPEDEF",
+	[BTF_KIND_VOLATILE]	= "VOLATILE",
+	[BTF_KIND_CONST]	= "CONST",
+	[BTF_KIND_RESTRICT]	= "RESTRICT",
+	[BTF_KIND_FUNC]		= "FUNC",
+	[BTF_KIND_FUNC_PROTO]	= "FUNC_PROTO",
+	[BTF_KIND_VAR]		= "VAR",
+	[BTF_KIND_DATASEC]	= "DATASEC",
+};
+
+static const char *btf_type_str(const struct btf_type *t)
+{
+	return btf_kind_str[BTF_INFO_KIND(t->info)];
+}
+
+/* Chunk size we use in safe copy of data to be shown. */
+#define BTF_SHOW_OBJ_SAFE_SIZE		32
+
+/*
+ * This is the maximum size of a base type value (equivalent to a
+ * 128-bit int); if we are at the end of our safe buffer and have
+ * less than 16 bytes space we can't be assured of being able
+ * to copy the next type safely, so in such cases we will initiate
+ * a new copy.
+ */
+#define BTF_SHOW_OBJ_BASE_TYPE_SIZE	16
+
+/* Type name size */
+#define BTF_SHOW_NAME_SIZE		80
+
+/*
+ * Common data to all BTF show operations. Private show functions can add
+ * their own data to a structure containing a struct btf_show and consult it
+ * in the show callback.  See btf_type_show() below.
+ *
+ * One challenge with showing nested data is we want to skip 0-valued
+ * data, but in order to figure out whether a nested object is all zeros
+ * we need to walk through it.  As a result, we need to make two passes
+ * when handling structs, unions and arrays; the first path simply looks
+ * for nonzero data, while the second actually does the display.  The first
+ * pass is signalled by show->state.depth_check being set, and if we
+ * encounter a non-zero value we set show->state.depth_to_show to
+ * the depth at which we encountered it.  When we have completed the
+ * first pass, we will know if anything needs to be displayed if
+ * depth_to_show > depth.  See btf_[struct,array]_show() for the
+ * implementation of this.
+ *
+ * Another problem is we want to ensure the data for display is safe to
+ * access.  To support this, the anonymous "struct {} obj" tracks the data
+ * object and our safe copy of it.  We copy portions of the data needed
+ * to the object "copy" buffer, but because its size is limited to
+ * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we
+ * traverse larger objects for display.
+ *
+ * The various data type show functions all start with a call to
+ * btf_show_start_type() which returns a pointer to the safe copy
+ * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the
+ * raw data itself).  btf_show_obj_safe() is responsible for
+ * using copy_from_kernel_nofault() to update the safe data if necessary
+ * as we traverse the object's data.  skbuff-like semantics are
+ * used:
+ *
+ * - obj.head points to the start of the toplevel object for display
+ * - obj.size is the size of the toplevel object
+ * - obj.data points to the current point in the original data at
+ *   which our safe data starts.  obj.data will advance as we copy
+ *   portions of the data.
+ *
+ * In most cases a single copy will suffice, but larger data structures
+ * such as "struct task_struct" will require many copies.  The logic in
+ * btf_show_obj_safe() handles the logic that determines if a new
+ * copy_from_kernel_nofault() is needed.
+ */
+struct btf_show {
+	u64 flags;
+	void *target;	/* target of show operation (seq file, buffer) */
+	void (*showfn)(struct btf_show *show, const char *fmt, va_list args);
+	const struct btf *btf;
+	/* below are used during iteration */
+	struct {
+		u8 depth;
+		u8 depth_to_show;
+		u8 depth_check;
+		u8 array_member:1,
+		   array_terminated:1;
+		u16 array_encoding;
+		u32 type_id;
+		int status;			/* non-zero for error */
+		const struct btf_type *type;
+		const struct btf_member *member;
+		char name[BTF_SHOW_NAME_SIZE];	/* space for member name/type */
+	} state;
+	struct {
+		u32 size;
+		void *head;
+		void *data;
+		u8 safe[BTF_SHOW_OBJ_SAFE_SIZE];
+	} obj;
+};
+
+struct btf_kind_operations {
+	s32 (*check_meta)(struct btf_verifier_env *env,
+			  const struct btf_type *t,
+			  u32 meta_left);
+	int (*resolve)(struct btf_verifier_env *env,
+		       const struct resolve_vertex *v);
+	int (*check_member)(struct btf_verifier_env *env,
+			    const struct btf_type *struct_type,
+			    const struct btf_member *member,
+			    const struct btf_type *member_type);
+	int (*check_kflag_member)(struct btf_verifier_env *env,
+				  const struct btf_type *struct_type,
+				  const struct btf_member *member,
+				  const struct btf_type *member_type);
+	void (*log_details)(struct btf_verifier_env *env,
+			    const struct btf_type *t);
+	void (*show)(const struct btf *btf, const struct btf_type *t,
+			 u32 type_id, void *data, u8 bits_offsets,
+			 struct btf_show *show);
+};
+
+static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
+static struct btf_type btf_void;
+
+static int btf_resolve(struct btf_verifier_env *env,
+		       const struct btf_type *t, u32 type_id);
+
+static bool btf_type_is_modifier(const struct btf_type *t)
+{
+	/* Some of them is not strictly a C modifier
+	 * but they are grouped into the same bucket
+	 * for BTF concern:
+	 *   A type (t) that refers to another
+	 *   type through t->type AND its size cannot
+	 *   be determined without following the t->type.
+	 *
+	 * ptr does not fall into this bucket
+	 * because its size is always sizeof(void *).
+	 */
+	switch (BTF_INFO_KIND(t->info)) {
+	case BTF_KIND_TYPEDEF:
+	case BTF_KIND_VOLATILE:
+	case BTF_KIND_CONST:
+	case BTF_KIND_RESTRICT:
+		return true;
+	}
+
+	return false;
+}
+
+bool btf_type_is_void(const struct btf_type *t)
+{
+	return t == &btf_void;
+}
+
+static bool btf_type_is_fwd(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
+}
+
+static bool btf_type_nosize(const struct btf_type *t)
+{
+	return btf_type_is_void(t) || btf_type_is_fwd(t) ||
+	       btf_type_is_func(t) || btf_type_is_func_proto(t);
+}
+
+static bool btf_type_nosize_or_null(const struct btf_type *t)
+{
+	return !t || btf_type_nosize(t);
+}
+
+static bool __btf_type_is_struct(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
+}
+
+static bool btf_type_is_array(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
+}
+
+static bool btf_type_is_datasec(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
+}
+
+s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
+{
+	const struct btf_type *t;
+	const char *tname;
+	u32 i;
+
+	for (i = 1; i <= btf->nr_types; i++) {
+		t = btf->types[i];
+		if (BTF_INFO_KIND(t->info) != kind)
+			continue;
+
+		tname = btf_name_by_offset(btf, t->name_off);
+		if (!strcmp(tname, name))
+			return i;
+	}
+
+	return -ENOENT;
+}
+
+const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
+					       u32 id, u32 *res_id)
+{
+	const struct btf_type *t = btf_type_by_id(btf, id);
+
+	while (btf_type_is_modifier(t)) {
+		id = t->type;
+		t = btf_type_by_id(btf, t->type);
+	}
+
+	if (res_id)
+		*res_id = id;
+
+	return t;
+}
+
+const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
+					    u32 id, u32 *res_id)
+{
+	const struct btf_type *t;
+
+	t = btf_type_skip_modifiers(btf, id, NULL);
+	if (!btf_type_is_ptr(t))
+		return NULL;
+
+	return btf_type_skip_modifiers(btf, t->type, res_id);
+}
+
+const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
+						 u32 id, u32 *res_id)
+{
+	const struct btf_type *ptype;
+
+	ptype = btf_type_resolve_ptr(btf, id, res_id);
+	if (ptype && btf_type_is_func_proto(ptype))
+		return ptype;
+
+	return NULL;
+}
+
+/* Types that act only as a source, not sink or intermediate
+ * type when resolving.
+ */
+static bool btf_type_is_resolve_source_only(const struct btf_type *t)
+{
+	return btf_type_is_var(t) ||
+	       btf_type_is_datasec(t);
+}
+
+/* What types need to be resolved?
+ *
+ * btf_type_is_modifier() is an obvious one.
+ *
+ * btf_type_is_struct() because its member refers to
+ * another type (through member->type).
+ *
+ * btf_type_is_var() because the variable refers to
+ * another type. btf_type_is_datasec() holds multiple
+ * btf_type_is_var() types that need resolving.
+ *
+ * btf_type_is_array() because its element (array->type)
+ * refers to another type.  Array can be thought of a
+ * special case of struct while array just has the same
+ * member-type repeated by array->nelems of times.
+ */
+static bool btf_type_needs_resolve(const struct btf_type *t)
+{
+	return btf_type_is_modifier(t) ||
+	       btf_type_is_ptr(t) ||
+	       btf_type_is_struct(t) ||
+	       btf_type_is_array(t) ||
+	       btf_type_is_var(t) ||
+	       btf_type_is_datasec(t);
+}
+
+/* t->size can be used */
+static bool btf_type_has_size(const struct btf_type *t)
+{
+	switch (BTF_INFO_KIND(t->info)) {
+	case BTF_KIND_INT:
+	case BTF_KIND_STRUCT:
+	case BTF_KIND_UNION:
+	case BTF_KIND_ENUM:
+	case BTF_KIND_DATASEC:
+		return true;
+	}
+
+	return false;
+}
+
+static const char *btf_int_encoding_str(u8 encoding)
+{
+	if (encoding == 0)
+		return "(none)";
+	else if (encoding == BTF_INT_SIGNED)
+		return "SIGNED";
+	else if (encoding == BTF_INT_CHAR)
+		return "CHAR";
+	else if (encoding == BTF_INT_BOOL)
+		return "BOOL";
+	else
+		return "UNKN";
+}
+
+static u32 btf_type_int(const struct btf_type *t)
+{
+	return *(u32 *)(t + 1);
+}
+
+static const struct btf_array *btf_type_array(const struct btf_type *t)
+{
+	return (const struct btf_array *)(t + 1);
+}
+
+static const struct btf_enum *btf_type_enum(const struct btf_type *t)
+{
+	return (const struct btf_enum *)(t + 1);
+}
+
+static const struct btf_var *btf_type_var(const struct btf_type *t)
+{
+	return (const struct btf_var *)(t + 1);
+}
+
+static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
+{
+	return kind_ops[BTF_INFO_KIND(t->info)];
+}
+
+static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
+{
+	return BTF_STR_OFFSET_VALID(offset) &&
+		offset < btf->hdr.str_len;
+}
+
+static bool __btf_name_char_ok(char c, bool first)
+{
+	if ((first ? !isalpha(c) :
+		     !isalnum(c)) &&
+	    c != '_' &&
+	    c != '.')
+		return false;
+	return true;
+}
+
+static bool __btf_name_valid(const struct btf *btf, u32 offset)
+{
+	/* offset must be valid */
+	const char *src = &btf->strings[offset];
+	const char *src_limit;
+
+	if (!__btf_name_char_ok(*src, true))
+		return false;
+
+	/* set a limit on identifier length */
+	src_limit = src + KSYM_NAME_LEN;
+	src++;
+	while (*src && src < src_limit) {
+		if (!__btf_name_char_ok(*src, false))
+			return false;
+		src++;
+	}
+
+	return !*src;
+}
+
+static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
+{
+	return __btf_name_valid(btf, offset);
+}
+
+static bool btf_name_valid_section(const struct btf *btf, u32 offset)
+{
+	return __btf_name_valid(btf, offset);
+}
+
+static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
+{
+	if (!offset)
+		return "(anon)";
+	else if (offset < btf->hdr.str_len)
+		return &btf->strings[offset];
+	else
+		return "(invalid-name-offset)";
+}
+
+const char *btf_name_by_offset(const struct btf *btf, u32 offset)
+{
+	if (offset < btf->hdr.str_len)
+		return &btf->strings[offset];
+
+	return NULL;
+}
+
+const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
+{
+	if (type_id > btf->nr_types)
+		return NULL;
+
+	return btf->types[type_id];
+}
+
+/*
+ * Regular int is not a bit field and it must be either
+ * u8/u16/u32/u64 or __int128.
+ */
+static bool btf_type_int_is_regular(const struct btf_type *t)
+{
+	u8 nr_bits, nr_bytes;
+	u32 int_data;
+
+	int_data = btf_type_int(t);
+	nr_bits = BTF_INT_BITS(int_data);
+	nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);
+	if (BITS_PER_BYTE_MASKED(nr_bits) ||
+	    BTF_INT_OFFSET(int_data) ||
+	    (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) &&
+	     nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) &&
+	     nr_bytes != (2 * sizeof(u64)))) {
+		return false;
+	}
+
+	return true;
+}
+
+/*
+ * Check that given struct member is a regular int with expected
+ * offset and size.
+ */
+bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
+			   const struct btf_member *m,
+			   u32 expected_offset, u32 expected_size)
+{
+	const struct btf_type *t;
+	u32 id, int_data;
+	u8 nr_bits;
+
+	id = m->type;
+	t = btf_type_id_size(btf, &id, NULL);
+	if (!t || !btf_type_is_int(t))
+		return false;
+
+	int_data = btf_type_int(t);
+	nr_bits = BTF_INT_BITS(int_data);
+	if (btf_type_kflag(s)) {
+		u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset);
+		u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset);
+
+		/* if kflag set, int should be a regular int and
+		 * bit offset should be at byte boundary.
+		 */
+		return !bitfield_size &&
+		       BITS_ROUNDUP_BYTES(bit_offset) == expected_offset &&
+		       BITS_ROUNDUP_BYTES(nr_bits) == expected_size;
+	}
+
+	if (BTF_INT_OFFSET(int_data) ||
+	    BITS_PER_BYTE_MASKED(m->offset) ||
+	    BITS_ROUNDUP_BYTES(m->offset) != expected_offset ||
+	    BITS_PER_BYTE_MASKED(nr_bits) ||
+	    BITS_ROUNDUP_BYTES(nr_bits) != expected_size)
+		return false;
+
+	return true;
+}
+
+/* Similar to btf_type_skip_modifiers() but does not skip typedefs. */
+static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf,
+						       u32 id)
+{
+	const struct btf_type *t = btf_type_by_id(btf, id);
+
+	while (btf_type_is_modifier(t) &&
+	       BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) {
+		id = t->type;
+		t = btf_type_by_id(btf, t->type);
+	}
+
+	return t;
+}
+
+#define BTF_SHOW_MAX_ITER	10
+
+#define BTF_KIND_BIT(kind)	(1ULL << kind)
+
+/*
+ * Populate show->state.name with type name information.
+ * Format of type name is
+ *
+ * [.member_name = ] (type_name)
+ */
+static const char *btf_show_name(struct btf_show *show)
+{
+	/* BTF_MAX_ITER array suffixes "[]" */
+	const char *array_suffixes = "[][][][][][][][][][]";
+	const char *array_suffix = &array_suffixes[strlen(array_suffixes)];
+	/* BTF_MAX_ITER pointer suffixes "*" */
+	const char *ptr_suffixes = "**********";
+	const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)];
+	const char *name = NULL, *prefix = "", *parens = "";
+	const struct btf_member *m = show->state.member;
+	const struct btf_type *t = show->state.type;
+	const struct btf_array *array;
+	u32 id = show->state.type_id;
+	const char *member = NULL;
+	bool show_member = false;
+	u64 kinds = 0;
+	int i;
+
+	show->state.name[0] = '\0';
+
+	/*
+	 * Don't show type name if we're showing an array member;
+	 * in that case we show the array type so don't need to repeat
+	 * ourselves for each member.
+	 */
+	if (show->state.array_member)
+		return "";
+
+	/* Retrieve member name, if any. */
+	if (m) {
+		member = btf_name_by_offset(show->btf, m->name_off);
+		show_member = strlen(member) > 0;
+		id = m->type;
+	}
+
+	/*
+	 * Start with type_id, as we have resolved the struct btf_type *
+	 * via btf_modifier_show() past the parent typedef to the child
+	 * struct, int etc it is defined as.  In such cases, the type_id
+	 * still represents the starting type while the struct btf_type *
+	 * in our show->state points at the resolved type of the typedef.
+	 */
+	t = btf_type_by_id(show->btf, id);
+	if (!t)
+		return "";
+
+	/*
+	 * The goal here is to build up the right number of pointer and
+	 * array suffixes while ensuring the type name for a typedef
+	 * is represented.  Along the way we accumulate a list of
+	 * BTF kinds we have encountered, since these will inform later
+	 * display; for example, pointer types will not require an
+	 * opening "{" for struct, we will just display the pointer value.
+	 *
+	 * We also want to accumulate the right number of pointer or array
+	 * indices in the format string while iterating until we get to
+	 * the typedef/pointee/array member target type.
+	 *
+	 * We start by pointing at the end of pointer and array suffix
+	 * strings; as we accumulate pointers and arrays we move the pointer
+	 * or array string backwards so it will show the expected number of
+	 * '*' or '[]' for the type.  BTF_SHOW_MAX_ITER of nesting of pointers
+	 * and/or arrays and typedefs are supported as a precaution.
+	 *
+	 * We also want to get typedef name while proceeding to resolve
+	 * type it points to so that we can add parentheses if it is a
+	 * "typedef struct" etc.
+	 */
+	for (i = 0; i < BTF_SHOW_MAX_ITER; i++) {
+
+		switch (BTF_INFO_KIND(t->info)) {
+		case BTF_KIND_TYPEDEF:
+			if (!name)
+				name = btf_name_by_offset(show->btf,
+							       t->name_off);
+			kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF);
+			id = t->type;
+			break;
+		case BTF_KIND_ARRAY:
+			kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY);
+			parens = "[";
+			if (!t)
+				return "";
+			array = btf_type_array(t);
+			if (array_suffix > array_suffixes)
+				array_suffix -= 2;
+			id = array->type;
+			break;
+		case BTF_KIND_PTR:
+			kinds |= BTF_KIND_BIT(BTF_KIND_PTR);
+			if (ptr_suffix > ptr_suffixes)
+				ptr_suffix -= 1;
+			id = t->type;
+			break;
+		default:
+			id = 0;
+			break;
+		}
+		if (!id)
+			break;
+		t = btf_type_skip_qualifiers(show->btf, id);
+	}
+	/* We may not be able to represent this type; bail to be safe */
+	if (i == BTF_SHOW_MAX_ITER)
+		return "";
+
+	if (!name)
+		name = btf_name_by_offset(show->btf, t->name_off);
+
+	switch (BTF_INFO_KIND(t->info)) {
+	case BTF_KIND_STRUCT:
+	case BTF_KIND_UNION:
+		prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ?
+			 "struct" : "union";
+		/* if it's an array of struct/union, parens is already set */
+		if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY))))
+			parens = "{";
+		break;
+	case BTF_KIND_ENUM:
+		prefix = "enum";
+		break;
+	default:
+		break;
+	}
+
+	/* pointer does not require parens */
+	if (kinds & BTF_KIND_BIT(BTF_KIND_PTR))
+		parens = "";
+	/* typedef does not require struct/union/enum prefix */
+	if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF))
+		prefix = "";
+
+	if (!name)
+		name = "";
+
+	/* Even if we don't want type name info, we want parentheses etc */
+	if (show->flags & BTF_SHOW_NONAME)
+		snprintf(show->state.name, sizeof(show->state.name), "%s",
+			 parens);
+	else
+		snprintf(show->state.name, sizeof(show->state.name),
+			 "%s%s%s(%s%s%s%s%s%s)%s",
+			 /* first 3 strings comprise ".member = " */
+			 show_member ? "." : "",
+			 show_member ? member : "",
+			 show_member ? " = " : "",
+			 /* ...next is our prefix (struct, enum, etc) */
+			 prefix,
+			 strlen(prefix) > 0 && strlen(name) > 0 ? " " : "",
+			 /* ...this is the type name itself */
+			 name,
+			 /* ...suffixed by the appropriate '*', '[]' suffixes */
+			 strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix,
+			 array_suffix, parens);
+
+	return show->state.name;
+}
+
+static const char *__btf_show_indent(struct btf_show *show)
+{
+	const char *indents = "                                ";
+	const char *indent = &indents[strlen(indents)];
+
+	if ((indent - show->state.depth) >= indents)
+		return indent - show->state.depth;
+	return indents;
+}
+
+static const char *btf_show_indent(struct btf_show *show)
+{
+	return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show);
+}
+
+static const char *btf_show_newline(struct btf_show *show)
+{
+	return show->flags & BTF_SHOW_COMPACT ? "" : "\n";
+}
+
+static const char *btf_show_delim(struct btf_show *show)
+{
+	if (show->state.depth == 0)
+		return "";
+
+	if ((show->flags & BTF_SHOW_COMPACT) && show->state.type &&
+		BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION)
+		return "|";
+
+	return ",";
+}
+
+__printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...)
+{
+	va_list args;
+
+	if (!show->state.depth_check) {
+		va_start(args, fmt);
+		show->showfn(show, fmt, args);
+		va_end(args);
+	}
+}
+
+/* Macros are used here as btf_show_type_value[s]() prepends and appends
+ * format specifiers to the format specifier passed in; these do the work of
+ * adding indentation, delimiters etc while the caller simply has to specify
+ * the type value(s) in the format specifier + value(s).
+ */
+#define btf_show_type_value(show, fmt, value)				       \
+	do {								       \
+		if ((value) != 0 || (show->flags & BTF_SHOW_ZERO) ||	       \
+		    show->state.depth == 0) {				       \
+			btf_show(show, "%s%s" fmt "%s%s",		       \
+				 btf_show_indent(show),			       \
+				 btf_show_name(show),			       \
+				 value, btf_show_delim(show),		       \
+				 btf_show_newline(show));		       \
+			if (show->state.depth > show->state.depth_to_show)     \
+				show->state.depth_to_show = show->state.depth; \
+		}							       \
+	} while (0)
+
+#define btf_show_type_values(show, fmt, ...)				       \
+	do {								       \
+		btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show),       \
+			 btf_show_name(show),				       \
+			 __VA_ARGS__, btf_show_delim(show),		       \
+			 btf_show_newline(show));			       \
+		if (show->state.depth > show->state.depth_to_show)	       \
+			show->state.depth_to_show = show->state.depth;	       \
+	} while (0)
+
+/* How much is left to copy to safe buffer after @data? */
+static int btf_show_obj_size_left(struct btf_show *show, void *data)
+{
+	return show->obj.head + show->obj.size - data;
+}
+
+/* Is object pointed to by @data of @size already copied to our safe buffer? */
+static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size)
+{
+	return data >= show->obj.data &&
+	       (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE);
+}
+
+/*
+ * If object pointed to by @data of @size falls within our safe buffer, return
+ * the equivalent pointer to the same safe data.  Assumes
+ * copy_from_kernel_nofault() has already happened and our safe buffer is
+ * populated.
+ */
+static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size)
+{
+	if (btf_show_obj_is_safe(show, data, size))
+		return show->obj.safe + (data - show->obj.data);
+	return NULL;
+}
+
+/*
+ * Return a safe-to-access version of data pointed to by @data.
+ * We do this by copying the relevant amount of information
+ * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault().
+ *
+ * If BTF_SHOW_UNSAFE is specified, just return data as-is; no
+ * safe copy is needed.
+ *
+ * Otherwise we need to determine if we have the required amount
+ * of data (determined by the @data pointer and the size of the
+ * largest base type we can encounter (represented by
+ * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures
+ * that we will be able to print some of the current object,
+ * and if more is needed a copy will be triggered.
+ * Some objects such as structs will not fit into the buffer;
+ * in such cases additional copies when we iterate over their
+ * members may be needed.
+ *
+ * btf_show_obj_safe() is used to return a safe buffer for
+ * btf_show_start_type(); this ensures that as we recurse into
+ * nested types we always have safe data for the given type.
+ * This approach is somewhat wasteful; it's possible for example
+ * that when iterating over a large union we'll end up copying the
+ * same data repeatedly, but the goal is safety not performance.
+ * We use stack data as opposed to per-CPU buffers because the
+ * iteration over a type can take some time, and preemption handling
+ * would greatly complicate use of the safe buffer.
+ */
+static void *btf_show_obj_safe(struct btf_show *show,
+			       const struct btf_type *t,
+			       void *data)
+{
+	const struct btf_type *rt;
+	int size_left, size;
+	void *safe = NULL;
+
+	if (show->flags & BTF_SHOW_UNSAFE)
+		return data;
+
+	rt = btf_resolve_size(show->btf, t, &size);
+	if (IS_ERR(rt)) {
+		show->state.status = PTR_ERR(rt);
+		return NULL;
+	}
+
+	/*
+	 * Is this toplevel object? If so, set total object size and
+	 * initialize pointers.  Otherwise check if we still fall within
+	 * our safe object data.
+	 */
+	if (show->state.depth == 0) {
+		show->obj.size = size;
+		show->obj.head = data;
+	} else {
+		/*
+		 * If the size of the current object is > our remaining
+		 * safe buffer we _may_ need to do a new copy.  However
+		 * consider the case of a nested struct; it's size pushes
+		 * us over the safe buffer limit, but showing any individual
+		 * struct members does not.  In such cases, we don't need
+		 * to initiate a fresh copy yet; however we definitely need
+		 * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left
+		 * in our buffer, regardless of the current object size.
+		 * The logic here is that as we resolve types we will
+		 * hit a base type at some point, and we need to be sure
+		 * the next chunk of data is safely available to display
+		 * that type info safely.  We cannot rely on the size of
+		 * the current object here because it may be much larger
+		 * than our current buffer (e.g. task_struct is 8k).
+		 * All we want to do here is ensure that we can print the
+		 * next basic type, which we can if either
+		 * - the current type size is within the safe buffer; or
+		 * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in
+		 *   the safe buffer.
+		 */
+		safe = __btf_show_obj_safe(show, data,
+					   min(size,
+					       BTF_SHOW_OBJ_BASE_TYPE_SIZE));
+	}
+
+	/*
+	 * We need a new copy to our safe object, either because we haven't
+	 * yet copied and are intializing safe data, or because the data
+	 * we want falls outside the boundaries of the safe object.
+	 */
+	if (!safe) {
+		size_left = btf_show_obj_size_left(show, data);
+		if (size_left > BTF_SHOW_OBJ_SAFE_SIZE)
+			size_left = BTF_SHOW_OBJ_SAFE_SIZE;
+		show->state.status = copy_from_kernel_nofault(show->obj.safe,
+							      data, size_left);
+		if (!show->state.status) {
+			show->obj.data = data;
+			safe = show->obj.safe;
+		}
+	}
+
+	return safe;
+}
+
+/*
+ * Set the type we are starting to show and return a safe data pointer
+ * to be used for showing the associated data.
+ */
+static void *btf_show_start_type(struct btf_show *show,
+				 const struct btf_type *t,
+				 u32 type_id, void *data)
+{
+	show->state.type = t;
+	show->state.type_id = type_id;
+	show->state.name[0] = '\0';
+
+	return btf_show_obj_safe(show, t, data);
+}
+
+static void btf_show_end_type(struct btf_show *show)
+{
+	show->state.type = NULL;
+	show->state.type_id = 0;
+	show->state.name[0] = '\0';
+}
+
+static void *btf_show_start_aggr_type(struct btf_show *show,
+				      const struct btf_type *t,
+				      u32 type_id, void *data)
+{
+	void *safe_data = btf_show_start_type(show, t, type_id, data);
+
+	if (!safe_data)
+		return safe_data;
+
+	btf_show(show, "%s%s%s", btf_show_indent(show),
+		 btf_show_name(show),
+		 btf_show_newline(show));
+	show->state.depth++;
+	return safe_data;
+}
+
+static void btf_show_end_aggr_type(struct btf_show *show,
+				   const char *suffix)
+{
+	show->state.depth--;
+	btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix,
+		 btf_show_delim(show), btf_show_newline(show));
+	btf_show_end_type(show);
+}
+
+static void btf_show_start_member(struct btf_show *show,
+				  const struct btf_member *m)
+{
+	show->state.member = m;
+}
+
+static void btf_show_start_array_member(struct btf_show *show)
+{
+	show->state.array_member = 1;
+	btf_show_start_member(show, NULL);
+}
+
+static void btf_show_end_member(struct btf_show *show)
+{
+	show->state.member = NULL;
+}
+
+static void btf_show_end_array_member(struct btf_show *show)
+{
+	show->state.array_member = 0;
+	btf_show_end_member(show);
+}
+
+static void *btf_show_start_array_type(struct btf_show *show,
+				       const struct btf_type *t,
+				       u32 type_id,
+				       u16 array_encoding,
+				       void *data)
+{
+	show->state.array_encoding = array_encoding;
+	show->state.array_terminated = 0;
+	return btf_show_start_aggr_type(show, t, type_id, data);
+}
+
+static void btf_show_end_array_type(struct btf_show *show)
+{
+	show->state.array_encoding = 0;
+	show->state.array_terminated = 0;
+	btf_show_end_aggr_type(show, "]");
+}
+
+static void *btf_show_start_struct_type(struct btf_show *show,
+					const struct btf_type *t,
+					u32 type_id,
+					void *data)
+{
+	return btf_show_start_aggr_type(show, t, type_id, data);
+}
+
+static void btf_show_end_struct_type(struct btf_show *show)
+{
+	btf_show_end_aggr_type(show, "}");
+}
+
+__printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
+					      const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	bpf_verifier_vlog(log, fmt, args);
+	va_end(args);
+}
+
+__printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env,
+					    const char *fmt, ...)
+{
+	struct bpf_verifier_log *log = &env->log;
+	va_list args;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+
+	va_start(args, fmt);
+	bpf_verifier_vlog(log, fmt, args);
+	va_end(args);
+}
+
+__printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
+						   const struct btf_type *t,
+						   bool log_details,
+						   const char *fmt, ...)
+{
+	struct bpf_verifier_log *log = &env->log;
+	u8 kind = BTF_INFO_KIND(t->info);
+	struct btf *btf = env->btf;
+	va_list args;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+
+	/* btf verifier prints all types it is processing via
+	 * btf_verifier_log_type(..., fmt = NULL).
+	 * Skip those prints for in-kernel BTF verification.
+	 */
+	if (log->level == BPF_LOG_KERNEL && !fmt)
+		return;
+
+	__btf_verifier_log(log, "[%u] %s %s%s",
+			   env->log_type_id,
+			   btf_kind_str[kind],
+			   __btf_name_by_offset(btf, t->name_off),
+			   log_details ? " " : "");
+
+	if (log_details)
+		btf_type_ops(t)->log_details(env, t);
+
+	if (fmt && *fmt) {
+		__btf_verifier_log(log, " ");
+		va_start(args, fmt);
+		bpf_verifier_vlog(log, fmt, args);
+		va_end(args);
+	}
+
+	__btf_verifier_log(log, "\n");
+}
+
+#define btf_verifier_log_type(env, t, ...) \
+	__btf_verifier_log_type((env), (t), true, __VA_ARGS__)
+#define btf_verifier_log_basic(env, t, ...) \
+	__btf_verifier_log_type((env), (t), false, __VA_ARGS__)
+
+__printf(4, 5)
+static void btf_verifier_log_member(struct btf_verifier_env *env,
+				    const struct btf_type *struct_type,
+				    const struct btf_member *member,
+				    const char *fmt, ...)
+{
+	struct bpf_verifier_log *log = &env->log;
+	struct btf *btf = env->btf;
+	va_list args;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+
+	if (log->level == BPF_LOG_KERNEL && !fmt)
+		return;
+	/* The CHECK_META phase already did a btf dump.
+	 *
+	 * If member is logged again, it must hit an error in
+	 * parsing this member.  It is useful to print out which
+	 * struct this member belongs to.
+	 */
+	if (env->phase != CHECK_META)
+		btf_verifier_log_type(env, struct_type, NULL);
+
+	if (btf_type_kflag(struct_type))
+		__btf_verifier_log(log,
+				   "\t%s type_id=%u bitfield_size=%u bits_offset=%u",
+				   __btf_name_by_offset(btf, member->name_off),
+				   member->type,
+				   BTF_MEMBER_BITFIELD_SIZE(member->offset),
+				   BTF_MEMBER_BIT_OFFSET(member->offset));
+	else
+		__btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u",
+				   __btf_name_by_offset(btf, member->name_off),
+				   member->type, member->offset);
+
+	if (fmt && *fmt) {
+		__btf_verifier_log(log, " ");
+		va_start(args, fmt);
+		bpf_verifier_vlog(log, fmt, args);
+		va_end(args);
+	}
+
+	__btf_verifier_log(log, "\n");
+}
+
+__printf(4, 5)
+static void btf_verifier_log_vsi(struct btf_verifier_env *env,
+				 const struct btf_type *datasec_type,
+				 const struct btf_var_secinfo *vsi,
+				 const char *fmt, ...)
+{
+	struct bpf_verifier_log *log = &env->log;
+	va_list args;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+	if (log->level == BPF_LOG_KERNEL && !fmt)
+		return;
+	if (env->phase != CHECK_META)
+		btf_verifier_log_type(env, datasec_type, NULL);
+
+	__btf_verifier_log(log, "\t type_id=%u offset=%u size=%u",
+			   vsi->type, vsi->offset, vsi->size);
+	if (fmt && *fmt) {
+		__btf_verifier_log(log, " ");
+		va_start(args, fmt);
+		bpf_verifier_vlog(log, fmt, args);
+		va_end(args);
+	}
+
+	__btf_verifier_log(log, "\n");
+}
+
+static void btf_verifier_log_hdr(struct btf_verifier_env *env,
+				 u32 btf_data_size)
+{
+	struct bpf_verifier_log *log = &env->log;
+	const struct btf *btf = env->btf;
+	const struct btf_header *hdr;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+
+	if (log->level == BPF_LOG_KERNEL)
+		return;
+	hdr = &btf->hdr;
+	__btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
+	__btf_verifier_log(log, "version: %u\n", hdr->version);
+	__btf_verifier_log(log, "flags: 0x%x\n", hdr->flags);
+	__btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len);
+	__btf_verifier_log(log, "type_off: %u\n", hdr->type_off);
+	__btf_verifier_log(log, "type_len: %u\n", hdr->type_len);
+	__btf_verifier_log(log, "str_off: %u\n", hdr->str_off);
+	__btf_verifier_log(log, "str_len: %u\n", hdr->str_len);
+	__btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size);
+}
+
+static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
+{
+	struct btf *btf = env->btf;
+
+	/* < 2 because +1 for btf_void which is always in btf->types[0].
+	 * btf_void is not accounted in btf->nr_types because btf_void
+	 * does not come from the BTF file.
+	 */
+	if (btf->types_size - btf->nr_types < 2) {
+		/* Expand 'types' array */
+
+		struct btf_type **new_types;
+		u32 expand_by, new_size;
+
+		if (btf->types_size == BTF_MAX_TYPE) {
+			btf_verifier_log(env, "Exceeded max num of types");
+			return -E2BIG;
+		}
+
+		expand_by = max_t(u32, btf->types_size >> 2, 16);
+		new_size = min_t(u32, BTF_MAX_TYPE,
+				 btf->types_size + expand_by);
+
+		new_types = kvcalloc(new_size, sizeof(*new_types),
+				     GFP_KERNEL | __GFP_NOWARN);
+		if (!new_types)
+			return -ENOMEM;
+
+		if (btf->nr_types == 0)
+			new_types[0] = &btf_void;
+		else
+			memcpy(new_types, btf->types,
+			       sizeof(*btf->types) * (btf->nr_types + 1));
+
+		kvfree(btf->types);
+		btf->types = new_types;
+		btf->types_size = new_size;
+	}
+
+	btf->types[++(btf->nr_types)] = t;
+
+	return 0;
+}
+
+static int btf_alloc_id(struct btf *btf)
+{
+	int id;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock_bh(&btf_idr_lock);
+	id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC);
+	if (id > 0)
+		btf->id = id;
+	spin_unlock_bh(&btf_idr_lock);
+	idr_preload_end();
+
+	if (WARN_ON_ONCE(!id))
+		return -ENOSPC;
+
+	return id > 0 ? 0 : id;
+}
+
+static void btf_free_id(struct btf *btf)
+{
+	unsigned long flags;
+
+	/*
+	 * In map-in-map, calling map_delete_elem() on outer
+	 * map will call bpf_map_put on the inner map.
+	 * It will then eventually call btf_free_id()
+	 * on the inner map.  Some of the map_delete_elem()
+	 * implementation may have irq disabled, so
+	 * we need to use the _irqsave() version instead
+	 * of the _bh() version.
+	 */
+	spin_lock_irqsave(&btf_idr_lock, flags);
+	idr_remove(&btf_idr, btf->id);
+	spin_unlock_irqrestore(&btf_idr_lock, flags);
+}
+
+static void btf_free(struct btf *btf)
+{
+	kvfree(btf->types);
+	kvfree(btf->resolved_sizes);
+	kvfree(btf->resolved_ids);
+	kvfree(btf->data);
+	kfree(btf);
+}
+
+static void btf_free_rcu(struct rcu_head *rcu)
+{
+	struct btf *btf = container_of(rcu, struct btf, rcu);
+
+	btf_free(btf);
+}
+
+void btf_put(struct btf *btf)
+{
+	if (btf && refcount_dec_and_test(&btf->refcnt)) {
+		btf_free_id(btf);
+		call_rcu(&btf->rcu, btf_free_rcu);
+	}
+}
+
+static int env_resolve_init(struct btf_verifier_env *env)
+{
+	struct btf *btf = env->btf;
+	u32 nr_types = btf->nr_types;
+	u32 *resolved_sizes = NULL;
+	u32 *resolved_ids = NULL;
+	u8 *visit_states = NULL;
+
+	/* +1 for btf_void */
+	resolved_sizes = kvcalloc(nr_types + 1, sizeof(*resolved_sizes),
+				  GFP_KERNEL | __GFP_NOWARN);
+	if (!resolved_sizes)
+		goto nomem;
+
+	resolved_ids = kvcalloc(nr_types + 1, sizeof(*resolved_ids),
+				GFP_KERNEL | __GFP_NOWARN);
+	if (!resolved_ids)
+		goto nomem;
+
+	visit_states = kvcalloc(nr_types + 1, sizeof(*visit_states),
+				GFP_KERNEL | __GFP_NOWARN);
+	if (!visit_states)
+		goto nomem;
+
+	btf->resolved_sizes = resolved_sizes;
+	btf->resolved_ids = resolved_ids;
+	env->visit_states = visit_states;
+
+	return 0;
+
+nomem:
+	kvfree(resolved_sizes);
+	kvfree(resolved_ids);
+	kvfree(visit_states);
+	return -ENOMEM;
+}
+
+static void btf_verifier_env_free(struct btf_verifier_env *env)
+{
+	kvfree(env->visit_states);
+	kfree(env);
+}
+
+static bool env_type_is_resolve_sink(const struct btf_verifier_env *env,
+				     const struct btf_type *next_type)
+{
+	switch (env->resolve_mode) {
+	case RESOLVE_TBD:
+		/* int, enum or void is a sink */
+		return !btf_type_needs_resolve(next_type);
+	case RESOLVE_PTR:
+		/* int, enum, void, struct, array, func or func_proto is a sink
+		 * for ptr
+		 */
+		return !btf_type_is_modifier(next_type) &&
+			!btf_type_is_ptr(next_type);
+	case RESOLVE_STRUCT_OR_ARRAY:
+		/* int, enum, void, ptr, func or func_proto is a sink
+		 * for struct and array
+		 */
+		return !btf_type_is_modifier(next_type) &&
+			!btf_type_is_array(next_type) &&
+			!btf_type_is_struct(next_type);
+	default:
+		BUG();
+	}
+}
+
+static bool env_type_is_resolved(const struct btf_verifier_env *env,
+				 u32 type_id)
+{
+	return env->visit_states[type_id] == RESOLVED;
+}
+
+static int env_stack_push(struct btf_verifier_env *env,
+			  const struct btf_type *t, u32 type_id)
+{
+	struct resolve_vertex *v;
+
+	if (env->top_stack == MAX_RESOLVE_DEPTH)
+		return -E2BIG;
+
+	if (env->visit_states[type_id] != NOT_VISITED)
+		return -EEXIST;
+
+	env->visit_states[type_id] = VISITED;
+
+	v = &env->stack[env->top_stack++];
+	v->t = t;
+	v->type_id = type_id;
+	v->next_member = 0;
+
+	if (env->resolve_mode == RESOLVE_TBD) {
+		if (btf_type_is_ptr(t))
+			env->resolve_mode = RESOLVE_PTR;
+		else if (btf_type_is_struct(t) || btf_type_is_array(t))
+			env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY;
+	}
+
+	return 0;
+}
+
+static void env_stack_set_next_member(struct btf_verifier_env *env,
+				      u16 next_member)
+{
+	env->stack[env->top_stack - 1].next_member = next_member;
+}
+
+static void env_stack_pop_resolved(struct btf_verifier_env *env,
+				   u32 resolved_type_id,
+				   u32 resolved_size)
+{
+	u32 type_id = env->stack[--(env->top_stack)].type_id;
+	struct btf *btf = env->btf;
+
+	btf->resolved_sizes[type_id] = resolved_size;
+	btf->resolved_ids[type_id] = resolved_type_id;
+	env->visit_states[type_id] = RESOLVED;
+}
+
+static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
+{
+	return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
+}
+
+/* Resolve the size of a passed-in "type"
+ *
+ * type: is an array (e.g. u32 array[x][y])
+ * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
+ * *type_size: (x * y * sizeof(u32)).  Hence, *type_size always
+ *             corresponds to the return type.
+ * *elem_type: u32
+ * *elem_id: id of u32
+ * *total_nelems: (x * y).  Hence, individual elem size is
+ *                (*type_size / *total_nelems)
+ * *type_id: id of type if it's changed within the function, 0 if not
+ *
+ * type: is not an array (e.g. const struct X)
+ * return type: type "struct X"
+ * *type_size: sizeof(struct X)
+ * *elem_type: same as return type ("struct X")
+ * *elem_id: 0
+ * *total_nelems: 1
+ * *type_id: id of type if it's changed within the function, 0 if not
+ */
+static const struct btf_type *
+__btf_resolve_size(const struct btf *btf, const struct btf_type *type,
+		   u32 *type_size, const struct btf_type **elem_type,
+		   u32 *elem_id, u32 *total_nelems, u32 *type_id)
+{
+	const struct btf_type *array_type = NULL;
+	const struct btf_array *array = NULL;
+	u32 i, size, nelems = 1, id = 0;
+
+	for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
+		switch (BTF_INFO_KIND(type->info)) {
+		/* type->size can be used */
+		case BTF_KIND_INT:
+		case BTF_KIND_STRUCT:
+		case BTF_KIND_UNION:
+		case BTF_KIND_ENUM:
+			size = type->size;
+			goto resolved;
+
+		case BTF_KIND_PTR:
+			size = sizeof(void *);
+			goto resolved;
+
+		/* Modifiers */
+		case BTF_KIND_TYPEDEF:
+		case BTF_KIND_VOLATILE:
+		case BTF_KIND_CONST:
+		case BTF_KIND_RESTRICT:
+			id = type->type;
+			type = btf_type_by_id(btf, type->type);
+			break;
+
+		case BTF_KIND_ARRAY:
+			if (!array_type)
+				array_type = type;
+			array = btf_type_array(type);
+			if (nelems && array->nelems > U32_MAX / nelems)
+				return ERR_PTR(-EINVAL);
+			nelems *= array->nelems;
+			type = btf_type_by_id(btf, array->type);
+			break;
+
+		/* type without size */
+		default:
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	return ERR_PTR(-EINVAL);
+
+resolved:
+	if (nelems && size > U32_MAX / nelems)
+		return ERR_PTR(-EINVAL);
+
+	*type_size = nelems * size;
+	if (total_nelems)
+		*total_nelems = nelems;
+	if (elem_type)
+		*elem_type = type;
+	if (elem_id)
+		*elem_id = array ? array->type : 0;
+	if (type_id && id)
+		*type_id = id;
+
+	return array_type ? : type;
+}
+
+const struct btf_type *
+btf_resolve_size(const struct btf *btf, const struct btf_type *type,
+		 u32 *type_size)
+{
+	return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL);
+}
+
+/* The input param "type_id" must point to a needs_resolve type */
+static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
+						  u32 *type_id)
+{
+	*type_id = btf->resolved_ids[*type_id];
+	return btf_type_by_id(btf, *type_id);
+}
+
+const struct btf_type *btf_type_id_size(const struct btf *btf,
+					u32 *type_id, u32 *ret_size)
+{
+	const struct btf_type *size_type;
+	u32 size_type_id = *type_id;
+	u32 size = 0;
+
+	size_type = btf_type_by_id(btf, size_type_id);
+	if (btf_type_nosize_or_null(size_type))
+		return NULL;
+
+	if (btf_type_has_size(size_type)) {
+		size = size_type->size;
+	} else if (btf_type_is_array(size_type)) {
+		size = btf->resolved_sizes[size_type_id];
+	} else if (btf_type_is_ptr(size_type)) {
+		size = sizeof(void *);
+	} else {
+		if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
+				 !btf_type_is_var(size_type)))
+			return NULL;
+
+		size_type_id = btf->resolved_ids[size_type_id];
+		size_type = btf_type_by_id(btf, size_type_id);
+		if (btf_type_nosize_or_null(size_type))
+			return NULL;
+		else if (btf_type_has_size(size_type))
+			size = size_type->size;
+		else if (btf_type_is_array(size_type))
+			size = btf->resolved_sizes[size_type_id];
+		else if (btf_type_is_ptr(size_type))
+			size = sizeof(void *);
+		else
+			return NULL;
+	}
+
+	*type_id = size_type_id;
+	if (ret_size)
+		*ret_size = size;
+
+	return size_type;
+}
+
+static int btf_df_check_member(struct btf_verifier_env *env,
+			       const struct btf_type *struct_type,
+			       const struct btf_member *member,
+			       const struct btf_type *member_type)
+{
+	btf_verifier_log_basic(env, struct_type,
+			       "Unsupported check_member");
+	return -EINVAL;
+}
+
+static int btf_df_check_kflag_member(struct btf_verifier_env *env,
+				     const struct btf_type *struct_type,
+				     const struct btf_member *member,
+				     const struct btf_type *member_type)
+{
+	btf_verifier_log_basic(env, struct_type,
+			       "Unsupported check_kflag_member");
+	return -EINVAL;
+}
+
+/* Used for ptr, array and struct/union type members.
+ * int, enum and modifier types have their specific callback functions.
+ */
+static int btf_generic_check_kflag_member(struct btf_verifier_env *env,
+					  const struct btf_type *struct_type,
+					  const struct btf_member *member,
+					  const struct btf_type *member_type)
+{
+	if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Invalid member bitfield_size");
+		return -EINVAL;
+	}
+
+	/* bitfield size is 0, so member->offset represents bit offset only.
+	 * It is safe to call non kflag check_member variants.
+	 */
+	return btf_type_ops(member_type)->check_member(env, struct_type,
+						       member,
+						       member_type);
+}
+
+static int btf_df_resolve(struct btf_verifier_env *env,
+			  const struct resolve_vertex *v)
+{
+	btf_verifier_log_basic(env, v->t, "Unsupported resolve");
+	return -EINVAL;
+}
+
+static void btf_df_show(const struct btf *btf, const struct btf_type *t,
+			u32 type_id, void *data, u8 bits_offsets,
+			struct btf_show *show)
+{
+	btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
+}
+
+static int btf_int_check_member(struct btf_verifier_env *env,
+				const struct btf_type *struct_type,
+				const struct btf_member *member,
+				const struct btf_type *member_type)
+{
+	u32 int_data = btf_type_int(member_type);
+	u32 struct_bits_off = member->offset;
+	u32 struct_size = struct_type->size;
+	u32 nr_copy_bits;
+	u32 bytes_offset;
+
+	if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"bits_offset exceeds U32_MAX");
+		return -EINVAL;
+	}
+
+	struct_bits_off += BTF_INT_OFFSET(int_data);
+	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+	nr_copy_bits = BTF_INT_BITS(int_data) +
+		BITS_PER_BYTE_MASKED(struct_bits_off);
+
+	if (nr_copy_bits > BITS_PER_U128) {
+		btf_verifier_log_member(env, struct_type, member,
+					"nr_copy_bits exceeds 128");
+		return -EINVAL;
+	}
+
+	if (struct_size < bytes_offset ||
+	    struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member exceeds struct_size");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int btf_int_check_kflag_member(struct btf_verifier_env *env,
+				      const struct btf_type *struct_type,
+				      const struct btf_member *member,
+				      const struct btf_type *member_type)
+{
+	u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset;
+	u32 int_data = btf_type_int(member_type);
+	u32 struct_size = struct_type->size;
+	u32 nr_copy_bits;
+
+	/* a regular int type is required for the kflag int member */
+	if (!btf_type_int_is_regular(member_type)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Invalid member base type");
+		return -EINVAL;
+	}
+
+	/* check sanity of bitfield size */
+	nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
+	struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
+	nr_int_data_bits = BTF_INT_BITS(int_data);
+	if (!nr_bits) {
+		/* Not a bitfield member, member offset must be at byte
+		 * boundary.
+		 */
+		if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+			btf_verifier_log_member(env, struct_type, member,
+						"Invalid member offset");
+			return -EINVAL;
+		}
+
+		nr_bits = nr_int_data_bits;
+	} else if (nr_bits > nr_int_data_bits) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Invalid member bitfield_size");
+		return -EINVAL;
+	}
+
+	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+	nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off);
+	if (nr_copy_bits > BITS_PER_U128) {
+		btf_verifier_log_member(env, struct_type, member,
+					"nr_copy_bits exceeds 128");
+		return -EINVAL;
+	}
+
+	if (struct_size < bytes_offset ||
+	    struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member exceeds struct_size");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static s32 btf_int_check_meta(struct btf_verifier_env *env,
+			      const struct btf_type *t,
+			      u32 meta_left)
+{
+	u32 int_data, nr_bits, meta_needed = sizeof(int_data);
+	u16 encoding;
+
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	if (btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen != 0");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	int_data = btf_type_int(t);
+	if (int_data & ~BTF_INT_MASK) {
+		btf_verifier_log_basic(env, t, "Invalid int_data:%x",
+				       int_data);
+		return -EINVAL;
+	}
+
+	nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data);
+
+	if (nr_bits > BITS_PER_U128) {
+		btf_verifier_log_type(env, t, "nr_bits exceeds %zu",
+				      BITS_PER_U128);
+		return -EINVAL;
+	}
+
+	if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) {
+		btf_verifier_log_type(env, t, "nr_bits exceeds type_size");
+		return -EINVAL;
+	}
+
+	/*
+	 * Only one of the encoding bits is allowed and it
+	 * should be sufficient for the pretty print purpose (i.e. decoding).
+	 * Multiple bits can be allowed later if it is found
+	 * to be insufficient.
+	 */
+	encoding = BTF_INT_ENCODING(int_data);
+	if (encoding &&
+	    encoding != BTF_INT_SIGNED &&
+	    encoding != BTF_INT_CHAR &&
+	    encoding != BTF_INT_BOOL) {
+		btf_verifier_log_type(env, t, "Unsupported encoding");
+		return -ENOTSUPP;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	return meta_needed;
+}
+
+static void btf_int_log(struct btf_verifier_env *env,
+			const struct btf_type *t)
+{
+	int int_data = btf_type_int(t);
+
+	btf_verifier_log(env,
+			 "size=%u bits_offset=%u nr_bits=%u encoding=%s",
+			 t->size, BTF_INT_OFFSET(int_data),
+			 BTF_INT_BITS(int_data),
+			 btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
+}
+
+static void btf_int128_print(struct btf_show *show, void *data)
+{
+	/* data points to a __int128 number.
+	 * Suppose
+	 *     int128_num = *(__int128 *)data;
+	 * The below formulas shows what upper_num and lower_num represents:
+	 *     upper_num = int128_num >> 64;
+	 *     lower_num = int128_num & 0xffffffffFFFFFFFFULL;
+	 */
+	u64 upper_num, lower_num;
+
+#ifdef __BIG_ENDIAN_BITFIELD
+	upper_num = *(u64 *)data;
+	lower_num = *(u64 *)(data + 8);
+#else
+	upper_num = *(u64 *)(data + 8);
+	lower_num = *(u64 *)data;
+#endif
+	if (upper_num == 0)
+		btf_show_type_value(show, "0x%llx", lower_num);
+	else
+		btf_show_type_values(show, "0x%llx%016llx", upper_num,
+				     lower_num);
+}
+
+static void btf_int128_shift(u64 *print_num, u16 left_shift_bits,
+			     u16 right_shift_bits)
+{
+	u64 upper_num, lower_num;
+
+#ifdef __BIG_ENDIAN_BITFIELD
+	upper_num = print_num[0];
+	lower_num = print_num[1];
+#else
+	upper_num = print_num[1];
+	lower_num = print_num[0];
+#endif
+
+	/* shake out un-needed bits by shift/or operations */
+	if (left_shift_bits >= 64) {
+		upper_num = lower_num << (left_shift_bits - 64);
+		lower_num = 0;
+	} else {
+		upper_num = (upper_num << left_shift_bits) |
+			    (lower_num >> (64 - left_shift_bits));
+		lower_num = lower_num << left_shift_bits;
+	}
+
+	if (right_shift_bits >= 64) {
+		lower_num = upper_num >> (right_shift_bits - 64);
+		upper_num = 0;
+	} else {
+		lower_num = (lower_num >> right_shift_bits) |
+			    (upper_num << (64 - right_shift_bits));
+		upper_num = upper_num >> right_shift_bits;
+	}
+
+#ifdef __BIG_ENDIAN_BITFIELD
+	print_num[0] = upper_num;
+	print_num[1] = lower_num;
+#else
+	print_num[0] = lower_num;
+	print_num[1] = upper_num;
+#endif
+}
+
+static void btf_bitfield_show(void *data, u8 bits_offset,
+			      u8 nr_bits, struct btf_show *show)
+{
+	u16 left_shift_bits, right_shift_bits;
+	u8 nr_copy_bytes;
+	u8 nr_copy_bits;
+	u64 print_num[2] = {};
+
+	nr_copy_bits = nr_bits + bits_offset;
+	nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits);
+
+	memcpy(print_num, data, nr_copy_bytes);
+
+#ifdef __BIG_ENDIAN_BITFIELD
+	left_shift_bits = bits_offset;
+#else
+	left_shift_bits = BITS_PER_U128 - nr_copy_bits;
+#endif
+	right_shift_bits = BITS_PER_U128 - nr_bits;
+
+	btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
+	btf_int128_print(show, print_num);
+}
+
+
+static void btf_int_bits_show(const struct btf *btf,
+			      const struct btf_type *t,
+			      void *data, u8 bits_offset,
+			      struct btf_show *show)
+{
+	u32 int_data = btf_type_int(t);
+	u8 nr_bits = BTF_INT_BITS(int_data);
+	u8 total_bits_offset;
+
+	/*
+	 * bits_offset is at most 7.
+	 * BTF_INT_OFFSET() cannot exceed 128 bits.
+	 */
+	total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
+	data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
+	bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
+	btf_bitfield_show(data, bits_offset, nr_bits, show);
+}
+
+static void btf_int_show(const struct btf *btf, const struct btf_type *t,
+			 u32 type_id, void *data, u8 bits_offset,
+			 struct btf_show *show)
+{
+	u32 int_data = btf_type_int(t);
+	u8 encoding = BTF_INT_ENCODING(int_data);
+	bool sign = encoding & BTF_INT_SIGNED;
+	u8 nr_bits = BTF_INT_BITS(int_data);
+	void *safe_data;
+
+	safe_data = btf_show_start_type(show, t, type_id, data);
+	if (!safe_data)
+		return;
+
+	if (bits_offset || BTF_INT_OFFSET(int_data) ||
+	    BITS_PER_BYTE_MASKED(nr_bits)) {
+		btf_int_bits_show(btf, t, safe_data, bits_offset, show);
+		goto out;
+	}
+
+	switch (nr_bits) {
+	case 128:
+		btf_int128_print(show, safe_data);
+		break;
+	case 64:
+		if (sign)
+			btf_show_type_value(show, "%lld", *(s64 *)safe_data);
+		else
+			btf_show_type_value(show, "%llu", *(u64 *)safe_data);
+		break;
+	case 32:
+		if (sign)
+			btf_show_type_value(show, "%d", *(s32 *)safe_data);
+		else
+			btf_show_type_value(show, "%u", *(u32 *)safe_data);
+		break;
+	case 16:
+		if (sign)
+			btf_show_type_value(show, "%d", *(s16 *)safe_data);
+		else
+			btf_show_type_value(show, "%u", *(u16 *)safe_data);
+		break;
+	case 8:
+		if (show->state.array_encoding == BTF_INT_CHAR) {
+			/* check for null terminator */
+			if (show->state.array_terminated)
+				break;
+			if (*(char *)data == '\0') {
+				show->state.array_terminated = 1;
+				break;
+			}
+			if (isprint(*(char *)data)) {
+				btf_show_type_value(show, "'%c'",
+						    *(char *)safe_data);
+				break;
+			}
+		}
+		if (sign)
+			btf_show_type_value(show, "%d", *(s8 *)safe_data);
+		else
+			btf_show_type_value(show, "%u", *(u8 *)safe_data);
+		break;
+	default:
+		btf_int_bits_show(btf, t, safe_data, bits_offset, show);
+		break;
+	}
+out:
+	btf_show_end_type(show);
+}
+
+static const struct btf_kind_operations int_ops = {
+	.check_meta = btf_int_check_meta,
+	.resolve = btf_df_resolve,
+	.check_member = btf_int_check_member,
+	.check_kflag_member = btf_int_check_kflag_member,
+	.log_details = btf_int_log,
+	.show = btf_int_show,
+};
+
+static int btf_modifier_check_member(struct btf_verifier_env *env,
+				     const struct btf_type *struct_type,
+				     const struct btf_member *member,
+				     const struct btf_type *member_type)
+{
+	const struct btf_type *resolved_type;
+	u32 resolved_type_id = member->type;
+	struct btf_member resolved_member;
+	struct btf *btf = env->btf;
+
+	resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
+	if (!resolved_type) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Invalid member");
+		return -EINVAL;
+	}
+
+	resolved_member = *member;
+	resolved_member.type = resolved_type_id;
+
+	return btf_type_ops(resolved_type)->check_member(env, struct_type,
+							 &resolved_member,
+							 resolved_type);
+}
+
+static int btf_modifier_check_kflag_member(struct btf_verifier_env *env,
+					   const struct btf_type *struct_type,
+					   const struct btf_member *member,
+					   const struct btf_type *member_type)
+{
+	const struct btf_type *resolved_type;
+	u32 resolved_type_id = member->type;
+	struct btf_member resolved_member;
+	struct btf *btf = env->btf;
+
+	resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
+	if (!resolved_type) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Invalid member");
+		return -EINVAL;
+	}
+
+	resolved_member = *member;
+	resolved_member.type = resolved_type_id;
+
+	return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type,
+							       &resolved_member,
+							       resolved_type);
+}
+
+static int btf_ptr_check_member(struct btf_verifier_env *env,
+				const struct btf_type *struct_type,
+				const struct btf_member *member,
+				const struct btf_type *member_type)
+{
+	u32 struct_size, struct_bits_off, bytes_offset;
+
+	struct_size = struct_type->size;
+	struct_bits_off = member->offset;
+	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+
+	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member is not byte aligned");
+		return -EINVAL;
+	}
+
+	if (struct_size - bytes_offset < sizeof(void *)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member exceeds struct_size");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int btf_ref_type_check_meta(struct btf_verifier_env *env,
+				   const struct btf_type *t,
+				   u32 meta_left)
+{
+	if (btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen != 0");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	if (!BTF_TYPE_ID_VALID(t->type)) {
+		btf_verifier_log_type(env, t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	/* typedef type must have a valid name, and other ref types,
+	 * volatile, const, restrict, should have a null name.
+	 */
+	if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
+		if (!t->name_off ||
+		    !btf_name_valid_identifier(env->btf, t->name_off)) {
+			btf_verifier_log_type(env, t, "Invalid name");
+			return -EINVAL;
+		}
+	} else {
+		if (t->name_off) {
+			btf_verifier_log_type(env, t, "Invalid name");
+			return -EINVAL;
+		}
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	return 0;
+}
+
+static int btf_modifier_resolve(struct btf_verifier_env *env,
+				const struct resolve_vertex *v)
+{
+	const struct btf_type *t = v->t;
+	const struct btf_type *next_type;
+	u32 next_type_id = t->type;
+	struct btf *btf = env->btf;
+
+	next_type = btf_type_by_id(btf, next_type_id);
+	if (!next_type || btf_type_is_resolve_source_only(next_type)) {
+		btf_verifier_log_type(env, v->t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	if (!env_type_is_resolve_sink(env, next_type) &&
+	    !env_type_is_resolved(env, next_type_id))
+		return env_stack_push(env, next_type, next_type_id);
+
+	/* Figure out the resolved next_type_id with size.
+	 * They will be stored in the current modifier's
+	 * resolved_ids and resolved_sizes such that it can
+	 * save us a few type-following when we use it later (e.g. in
+	 * pretty print).
+	 */
+	if (!btf_type_id_size(btf, &next_type_id, NULL)) {
+		if (env_type_is_resolved(env, next_type_id))
+			next_type = btf_type_id_resolve(btf, &next_type_id);
+
+		/* "typedef void new_void", "const void"...etc */
+		if (!btf_type_is_void(next_type) &&
+		    !btf_type_is_fwd(next_type) &&
+		    !btf_type_is_func_proto(next_type)) {
+			btf_verifier_log_type(env, v->t, "Invalid type_id");
+			return -EINVAL;
+		}
+	}
+
+	env_stack_pop_resolved(env, next_type_id, 0);
+
+	return 0;
+}
+
+static int btf_var_resolve(struct btf_verifier_env *env,
+			   const struct resolve_vertex *v)
+{
+	const struct btf_type *next_type;
+	const struct btf_type *t = v->t;
+	u32 next_type_id = t->type;
+	struct btf *btf = env->btf;
+
+	next_type = btf_type_by_id(btf, next_type_id);
+	if (!next_type || btf_type_is_resolve_source_only(next_type)) {
+		btf_verifier_log_type(env, v->t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	if (!env_type_is_resolve_sink(env, next_type) &&
+	    !env_type_is_resolved(env, next_type_id))
+		return env_stack_push(env, next_type, next_type_id);
+
+	if (btf_type_is_modifier(next_type)) {
+		const struct btf_type *resolved_type;
+		u32 resolved_type_id;
+
+		resolved_type_id = next_type_id;
+		resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
+
+		if (btf_type_is_ptr(resolved_type) &&
+		    !env_type_is_resolve_sink(env, resolved_type) &&
+		    !env_type_is_resolved(env, resolved_type_id))
+			return env_stack_push(env, resolved_type,
+					      resolved_type_id);
+	}
+
+	/* We must resolve to something concrete at this point, no
+	 * forward types or similar that would resolve to size of
+	 * zero is allowed.
+	 */
+	if (!btf_type_id_size(btf, &next_type_id, NULL)) {
+		btf_verifier_log_type(env, v->t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	env_stack_pop_resolved(env, next_type_id, 0);
+
+	return 0;
+}
+
+static int btf_ptr_resolve(struct btf_verifier_env *env,
+			   const struct resolve_vertex *v)
+{
+	const struct btf_type *next_type;
+	const struct btf_type *t = v->t;
+	u32 next_type_id = t->type;
+	struct btf *btf = env->btf;
+
+	next_type = btf_type_by_id(btf, next_type_id);
+	if (!next_type || btf_type_is_resolve_source_only(next_type)) {
+		btf_verifier_log_type(env, v->t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	if (!env_type_is_resolve_sink(env, next_type) &&
+	    !env_type_is_resolved(env, next_type_id))
+		return env_stack_push(env, next_type, next_type_id);
+
+	/* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY,
+	 * the modifier may have stopped resolving when it was resolved
+	 * to a ptr (last-resolved-ptr).
+	 *
+	 * We now need to continue from the last-resolved-ptr to
+	 * ensure the last-resolved-ptr will not referring back to
+	 * the currenct ptr (t).
+	 */
+	if (btf_type_is_modifier(next_type)) {
+		const struct btf_type *resolved_type;
+		u32 resolved_type_id;
+
+		resolved_type_id = next_type_id;
+		resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
+
+		if (btf_type_is_ptr(resolved_type) &&
+		    !env_type_is_resolve_sink(env, resolved_type) &&
+		    !env_type_is_resolved(env, resolved_type_id))
+			return env_stack_push(env, resolved_type,
+					      resolved_type_id);
+	}
+
+	if (!btf_type_id_size(btf, &next_type_id, NULL)) {
+		if (env_type_is_resolved(env, next_type_id))
+			next_type = btf_type_id_resolve(btf, &next_type_id);
+
+		if (!btf_type_is_void(next_type) &&
+		    !btf_type_is_fwd(next_type) &&
+		    !btf_type_is_func_proto(next_type)) {
+			btf_verifier_log_type(env, v->t, "Invalid type_id");
+			return -EINVAL;
+		}
+	}
+
+	env_stack_pop_resolved(env, next_type_id, 0);
+
+	return 0;
+}
+
+static void btf_modifier_show(const struct btf *btf,
+			      const struct btf_type *t,
+			      u32 type_id, void *data,
+			      u8 bits_offset, struct btf_show *show)
+{
+	if (btf->resolved_ids)
+		t = btf_type_id_resolve(btf, &type_id);
+	else
+		t = btf_type_skip_modifiers(btf, type_id, NULL);
+
+	btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
+}
+
+static void btf_var_show(const struct btf *btf, const struct btf_type *t,
+			 u32 type_id, void *data, u8 bits_offset,
+			 struct btf_show *show)
+{
+	t = btf_type_id_resolve(btf, &type_id);
+
+	btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
+}
+
+static void btf_ptr_show(const struct btf *btf, const struct btf_type *t,
+			 u32 type_id, void *data, u8 bits_offset,
+			 struct btf_show *show)
+{
+	void *safe_data;
+
+	safe_data = btf_show_start_type(show, t, type_id, data);
+	if (!safe_data)
+		return;
+
+	/* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */
+	if (show->flags & BTF_SHOW_PTR_RAW)
+		btf_show_type_value(show, "0x%px", *(void **)safe_data);
+	else
+		btf_show_type_value(show, "0x%p", *(void **)safe_data);
+	btf_show_end_type(show);
+}
+
+static void btf_ref_type_log(struct btf_verifier_env *env,
+			     const struct btf_type *t)
+{
+	btf_verifier_log(env, "type_id=%u", t->type);
+}
+
+static struct btf_kind_operations modifier_ops = {
+	.check_meta = btf_ref_type_check_meta,
+	.resolve = btf_modifier_resolve,
+	.check_member = btf_modifier_check_member,
+	.check_kflag_member = btf_modifier_check_kflag_member,
+	.log_details = btf_ref_type_log,
+	.show = btf_modifier_show,
+};
+
+static struct btf_kind_operations ptr_ops = {
+	.check_meta = btf_ref_type_check_meta,
+	.resolve = btf_ptr_resolve,
+	.check_member = btf_ptr_check_member,
+	.check_kflag_member = btf_generic_check_kflag_member,
+	.log_details = btf_ref_type_log,
+	.show = btf_ptr_show,
+};
+
+static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
+			      const struct btf_type *t,
+			      u32 meta_left)
+{
+	if (btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen != 0");
+		return -EINVAL;
+	}
+
+	if (t->type) {
+		btf_verifier_log_type(env, t, "type != 0");
+		return -EINVAL;
+	}
+
+	/* fwd type must have a valid name */
+	if (!t->name_off ||
+	    !btf_name_valid_identifier(env->btf, t->name_off)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	return 0;
+}
+
+static void btf_fwd_type_log(struct btf_verifier_env *env,
+			     const struct btf_type *t)
+{
+	btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct");
+}
+
+static struct btf_kind_operations fwd_ops = {
+	.check_meta = btf_fwd_check_meta,
+	.resolve = btf_df_resolve,
+	.check_member = btf_df_check_member,
+	.check_kflag_member = btf_df_check_kflag_member,
+	.log_details = btf_fwd_type_log,
+	.show = btf_df_show,
+};
+
+static int btf_array_check_member(struct btf_verifier_env *env,
+				  const struct btf_type *struct_type,
+				  const struct btf_member *member,
+				  const struct btf_type *member_type)
+{
+	u32 struct_bits_off = member->offset;
+	u32 struct_size, bytes_offset;
+	u32 array_type_id, array_size;
+	struct btf *btf = env->btf;
+
+	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member is not byte aligned");
+		return -EINVAL;
+	}
+
+	array_type_id = member->type;
+	btf_type_id_size(btf, &array_type_id, &array_size);
+	struct_size = struct_type->size;
+	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+	if (struct_size - bytes_offset < array_size) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member exceeds struct_size");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static s32 btf_array_check_meta(struct btf_verifier_env *env,
+				const struct btf_type *t,
+				u32 meta_left)
+{
+	const struct btf_array *array = btf_type_array(t);
+	u32 meta_needed = sizeof(*array);
+
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	/* array type should not have a name */
+	if (t->name_off) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	if (btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen != 0");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	if (t->size) {
+		btf_verifier_log_type(env, t, "size != 0");
+		return -EINVAL;
+	}
+
+	/* Array elem type and index type cannot be in type void,
+	 * so !array->type and !array->index_type are not allowed.
+	 */
+	if (!array->type || !BTF_TYPE_ID_VALID(array->type)) {
+		btf_verifier_log_type(env, t, "Invalid elem");
+		return -EINVAL;
+	}
+
+	if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) {
+		btf_verifier_log_type(env, t, "Invalid index");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	return meta_needed;
+}
+
+static int btf_array_resolve(struct btf_verifier_env *env,
+			     const struct resolve_vertex *v)
+{
+	const struct btf_array *array = btf_type_array(v->t);
+	const struct btf_type *elem_type, *index_type;
+	u32 elem_type_id, index_type_id;
+	struct btf *btf = env->btf;
+	u32 elem_size;
+
+	/* Check array->index_type */
+	index_type_id = array->index_type;
+	index_type = btf_type_by_id(btf, index_type_id);
+	if (btf_type_nosize_or_null(index_type) ||
+	    btf_type_is_resolve_source_only(index_type)) {
+		btf_verifier_log_type(env, v->t, "Invalid index");
+		return -EINVAL;
+	}
+
+	if (!env_type_is_resolve_sink(env, index_type) &&
+	    !env_type_is_resolved(env, index_type_id))
+		return env_stack_push(env, index_type, index_type_id);
+
+	index_type = btf_type_id_size(btf, &index_type_id, NULL);
+	if (!index_type || !btf_type_is_int(index_type) ||
+	    !btf_type_int_is_regular(index_type)) {
+		btf_verifier_log_type(env, v->t, "Invalid index");
+		return -EINVAL;
+	}
+
+	/* Check array->type */
+	elem_type_id = array->type;
+	elem_type = btf_type_by_id(btf, elem_type_id);
+	if (btf_type_nosize_or_null(elem_type) ||
+	    btf_type_is_resolve_source_only(elem_type)) {
+		btf_verifier_log_type(env, v->t,
+				      "Invalid elem");
+		return -EINVAL;
+	}
+
+	if (!env_type_is_resolve_sink(env, elem_type) &&
+	    !env_type_is_resolved(env, elem_type_id))
+		return env_stack_push(env, elem_type, elem_type_id);
+
+	elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
+	if (!elem_type) {
+		btf_verifier_log_type(env, v->t, "Invalid elem");
+		return -EINVAL;
+	}
+
+	if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) {
+		btf_verifier_log_type(env, v->t, "Invalid array of int");
+		return -EINVAL;
+	}
+
+	if (array->nelems && elem_size > U32_MAX / array->nelems) {
+		btf_verifier_log_type(env, v->t,
+				      "Array size overflows U32_MAX");
+		return -EINVAL;
+	}
+
+	env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems);
+
+	return 0;
+}
+
+static void btf_array_log(struct btf_verifier_env *env,
+			  const struct btf_type *t)
+{
+	const struct btf_array *array = btf_type_array(t);
+
+	btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u",
+			 array->type, array->index_type, array->nelems);
+}
+
+static void __btf_array_show(const struct btf *btf, const struct btf_type *t,
+			     u32 type_id, void *data, u8 bits_offset,
+			     struct btf_show *show)
+{
+	const struct btf_array *array = btf_type_array(t);
+	const struct btf_kind_operations *elem_ops;
+	const struct btf_type *elem_type;
+	u32 i, elem_size = 0, elem_type_id;
+	u16 encoding = 0;
+
+	elem_type_id = array->type;
+	elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL);
+	if (elem_type && btf_type_has_size(elem_type))
+		elem_size = elem_type->size;
+
+	if (elem_type && btf_type_is_int(elem_type)) {
+		u32 int_type = btf_type_int(elem_type);
+
+		encoding = BTF_INT_ENCODING(int_type);
+
+		/*
+		 * BTF_INT_CHAR encoding never seems to be set for
+		 * char arrays, so if size is 1 and element is
+		 * printable as a char, we'll do that.
+		 */
+		if (elem_size == 1)
+			encoding = BTF_INT_CHAR;
+	}
+
+	if (!btf_show_start_array_type(show, t, type_id, encoding, data))
+		return;
+
+	if (!elem_type)
+		goto out;
+	elem_ops = btf_type_ops(elem_type);
+
+	for (i = 0; i < array->nelems; i++) {
+
+		btf_show_start_array_member(show);
+
+		elem_ops->show(btf, elem_type, elem_type_id, data,
+			       bits_offset, show);
+		data += elem_size;
+
+		btf_show_end_array_member(show);
+
+		if (show->state.array_terminated)
+			break;
+	}
+out:
+	btf_show_end_array_type(show);
+}
+
+static void btf_array_show(const struct btf *btf, const struct btf_type *t,
+			   u32 type_id, void *data, u8 bits_offset,
+			   struct btf_show *show)
+{
+	const struct btf_member *m = show->state.member;
+
+	/*
+	 * First check if any members would be shown (are non-zero).
+	 * See comments above "struct btf_show" definition for more
+	 * details on how this works at a high-level.
+	 */
+	if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
+		if (!show->state.depth_check) {
+			show->state.depth_check = show->state.depth + 1;
+			show->state.depth_to_show = 0;
+		}
+		__btf_array_show(btf, t, type_id, data, bits_offset, show);
+		show->state.member = m;
+
+		if (show->state.depth_check != show->state.depth + 1)
+			return;
+		show->state.depth_check = 0;
+
+		if (show->state.depth_to_show <= show->state.depth)
+			return;
+		/*
+		 * Reaching here indicates we have recursed and found
+		 * non-zero array member(s).
+		 */
+	}
+	__btf_array_show(btf, t, type_id, data, bits_offset, show);
+}
+
+static struct btf_kind_operations array_ops = {
+	.check_meta = btf_array_check_meta,
+	.resolve = btf_array_resolve,
+	.check_member = btf_array_check_member,
+	.check_kflag_member = btf_generic_check_kflag_member,
+	.log_details = btf_array_log,
+	.show = btf_array_show,
+};
+
+static int btf_struct_check_member(struct btf_verifier_env *env,
+				   const struct btf_type *struct_type,
+				   const struct btf_member *member,
+				   const struct btf_type *member_type)
+{
+	u32 struct_bits_off = member->offset;
+	u32 struct_size, bytes_offset;
+
+	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member is not byte aligned");
+		return -EINVAL;
+	}
+
+	struct_size = struct_type->size;
+	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+	if (struct_size - bytes_offset < member_type->size) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member exceeds struct_size");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static s32 btf_struct_check_meta(struct btf_verifier_env *env,
+				 const struct btf_type *t,
+				 u32 meta_left)
+{
+	bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION;
+	const struct btf_member *member;
+	u32 meta_needed, last_offset;
+	struct btf *btf = env->btf;
+	u32 struct_size = t->size;
+	u32 offset;
+	u16 i;
+
+	meta_needed = btf_type_vlen(t) * sizeof(*member);
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	/* struct type either no name or a valid one */
+	if (t->name_off &&
+	    !btf_name_valid_identifier(env->btf, t->name_off)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	last_offset = 0;
+	for_each_member(i, t, member) {
+		if (!btf_name_offset_valid(btf, member->name_off)) {
+			btf_verifier_log_member(env, t, member,
+						"Invalid member name_offset:%u",
+						member->name_off);
+			return -EINVAL;
+		}
+
+		/* struct member either no name or a valid one */
+		if (member->name_off &&
+		    !btf_name_valid_identifier(btf, member->name_off)) {
+			btf_verifier_log_member(env, t, member, "Invalid name");
+			return -EINVAL;
+		}
+		/* A member cannot be in type void */
+		if (!member->type || !BTF_TYPE_ID_VALID(member->type)) {
+			btf_verifier_log_member(env, t, member,
+						"Invalid type_id");
+			return -EINVAL;
+		}
+
+		offset = btf_member_bit_offset(t, member);
+		if (is_union && offset) {
+			btf_verifier_log_member(env, t, member,
+						"Invalid member bits_offset");
+			return -EINVAL;
+		}
+
+		/*
+		 * ">" instead of ">=" because the last member could be
+		 * "char a[0];"
+		 */
+		if (last_offset > offset) {
+			btf_verifier_log_member(env, t, member,
+						"Invalid member bits_offset");
+			return -EINVAL;
+		}
+
+		if (BITS_ROUNDUP_BYTES(offset) > struct_size) {
+			btf_verifier_log_member(env, t, member,
+						"Member bits_offset exceeds its struct size");
+			return -EINVAL;
+		}
+
+		btf_verifier_log_member(env, t, member, NULL);
+		last_offset = offset;
+	}
+
+	return meta_needed;
+}
+
+static int btf_struct_resolve(struct btf_verifier_env *env,
+			      const struct resolve_vertex *v)
+{
+	const struct btf_member *member;
+	int err;
+	u16 i;
+
+	/* Before continue resolving the next_member,
+	 * ensure the last member is indeed resolved to a
+	 * type with size info.
+	 */
+	if (v->next_member) {
+		const struct btf_type *last_member_type;
+		const struct btf_member *last_member;
+		u32 last_member_type_id;
+
+		last_member = btf_type_member(v->t) + v->next_member - 1;
+		last_member_type_id = last_member->type;
+		if (WARN_ON_ONCE(!env_type_is_resolved(env,
+						       last_member_type_id)))
+			return -EINVAL;
+
+		last_member_type = btf_type_by_id(env->btf,
+						  last_member_type_id);
+		if (btf_type_kflag(v->t))
+			err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t,
+								last_member,
+								last_member_type);
+		else
+			err = btf_type_ops(last_member_type)->check_member(env, v->t,
+								last_member,
+								last_member_type);
+		if (err)
+			return err;
+	}
+
+	for_each_member_from(i, v->next_member, v->t, member) {
+		u32 member_type_id = member->type;
+		const struct btf_type *member_type = btf_type_by_id(env->btf,
+								member_type_id);
+
+		if (btf_type_nosize_or_null(member_type) ||
+		    btf_type_is_resolve_source_only(member_type)) {
+			btf_verifier_log_member(env, v->t, member,
+						"Invalid member");
+			return -EINVAL;
+		}
+
+		if (!env_type_is_resolve_sink(env, member_type) &&
+		    !env_type_is_resolved(env, member_type_id)) {
+			env_stack_set_next_member(env, i + 1);
+			return env_stack_push(env, member_type, member_type_id);
+		}
+
+		if (btf_type_kflag(v->t))
+			err = btf_type_ops(member_type)->check_kflag_member(env, v->t,
+									    member,
+									    member_type);
+		else
+			err = btf_type_ops(member_type)->check_member(env, v->t,
+								      member,
+								      member_type);
+		if (err)
+			return err;
+	}
+
+	env_stack_pop_resolved(env, 0, 0);
+
+	return 0;
+}
+
+static void btf_struct_log(struct btf_verifier_env *env,
+			   const struct btf_type *t)
+{
+	btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
+}
+
+/* find 'struct bpf_spin_lock' in map value.
+ * return >= 0 offset if found
+ * and < 0 in case of error
+ */
+int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t)
+{
+	const struct btf_member *member;
+	u32 i, off = -ENOENT;
+
+	if (!__btf_type_is_struct(t))
+		return -EINVAL;
+
+	for_each_member(i, t, member) {
+		const struct btf_type *member_type = btf_type_by_id(btf,
+								    member->type);
+		if (!__btf_type_is_struct(member_type))
+			continue;
+		if (member_type->size != sizeof(struct bpf_spin_lock))
+			continue;
+		if (strcmp(__btf_name_by_offset(btf, member_type->name_off),
+			   "bpf_spin_lock"))
+			continue;
+		if (off != -ENOENT)
+			/* only one 'struct bpf_spin_lock' is allowed */
+			return -E2BIG;
+		off = btf_member_bit_offset(t, member);
+		if (off % 8)
+			/* valid C code cannot generate such BTF */
+			return -EINVAL;
+		off /= 8;
+		if (off % __alignof__(struct bpf_spin_lock))
+			/* valid struct bpf_spin_lock will be 4 byte aligned */
+			return -EINVAL;
+	}
+	return off;
+}
+
+static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
+			      u32 type_id, void *data, u8 bits_offset,
+			      struct btf_show *show)
+{
+	const struct btf_member *member;
+	void *safe_data;
+	u32 i;
+
+	safe_data = btf_show_start_struct_type(show, t, type_id, data);
+	if (!safe_data)
+		return;
+
+	for_each_member(i, t, member) {
+		const struct btf_type *member_type = btf_type_by_id(btf,
+								member->type);
+		const struct btf_kind_operations *ops;
+		u32 member_offset, bitfield_size;
+		u32 bytes_offset;
+		u8 bits8_offset;
+
+		btf_show_start_member(show, member);
+
+		member_offset = btf_member_bit_offset(t, member);
+		bitfield_size = btf_member_bitfield_size(t, member);
+		bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset);
+		bits8_offset = BITS_PER_BYTE_MASKED(member_offset);
+		if (bitfield_size) {
+			safe_data = btf_show_start_type(show, member_type,
+							member->type,
+							data + bytes_offset);
+			if (safe_data)
+				btf_bitfield_show(safe_data,
+						  bits8_offset,
+						  bitfield_size, show);
+			btf_show_end_type(show);
+		} else {
+			ops = btf_type_ops(member_type);
+			ops->show(btf, member_type, member->type,
+				  data + bytes_offset, bits8_offset, show);
+		}
+
+		btf_show_end_member(show);
+	}
+
+	btf_show_end_struct_type(show);
+}
+
+static void btf_struct_show(const struct btf *btf, const struct btf_type *t,
+			    u32 type_id, void *data, u8 bits_offset,
+			    struct btf_show *show)
+{
+	const struct btf_member *m = show->state.member;
+
+	/*
+	 * First check if any members would be shown (are non-zero).
+	 * See comments above "struct btf_show" definition for more
+	 * details on how this works at a high-level.
+	 */
+	if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
+		if (!show->state.depth_check) {
+			show->state.depth_check = show->state.depth + 1;
+			show->state.depth_to_show = 0;
+		}
+		__btf_struct_show(btf, t, type_id, data, bits_offset, show);
+		/* Restore saved member data here */
+		show->state.member = m;
+		if (show->state.depth_check != show->state.depth + 1)
+			return;
+		show->state.depth_check = 0;
+
+		if (show->state.depth_to_show <= show->state.depth)
+			return;
+		/*
+		 * Reaching here indicates we have recursed and found
+		 * non-zero child values.
+		 */
+	}
+
+	__btf_struct_show(btf, t, type_id, data, bits_offset, show);
+}
+
+static struct btf_kind_operations struct_ops = {
+	.check_meta = btf_struct_check_meta,
+	.resolve = btf_struct_resolve,
+	.check_member = btf_struct_check_member,
+	.check_kflag_member = btf_generic_check_kflag_member,
+	.log_details = btf_struct_log,
+	.show = btf_struct_show,
+};
+
+static int btf_enum_check_member(struct btf_verifier_env *env,
+				 const struct btf_type *struct_type,
+				 const struct btf_member *member,
+				 const struct btf_type *member_type)
+{
+	u32 struct_bits_off = member->offset;
+	u32 struct_size, bytes_offset;
+
+	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member is not byte aligned");
+		return -EINVAL;
+	}
+
+	struct_size = struct_type->size;
+	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+	if (struct_size - bytes_offset < member_type->size) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member exceeds struct_size");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int btf_enum_check_kflag_member(struct btf_verifier_env *env,
+				       const struct btf_type *struct_type,
+				       const struct btf_member *member,
+				       const struct btf_type *member_type)
+{
+	u32 struct_bits_off, nr_bits, bytes_end, struct_size;
+	u32 int_bitsize = sizeof(int) * BITS_PER_BYTE;
+
+	struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
+	nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
+	if (!nr_bits) {
+		if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+			btf_verifier_log_member(env, struct_type, member,
+						"Member is not byte aligned");
+			return -EINVAL;
+		}
+
+		nr_bits = int_bitsize;
+	} else if (nr_bits > int_bitsize) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Invalid member bitfield_size");
+		return -EINVAL;
+	}
+
+	struct_size = struct_type->size;
+	bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits);
+	if (struct_size < bytes_end) {
+		btf_verifier_log_member(env, struct_type, member,
+					"Member exceeds struct_size");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static s32 btf_enum_check_meta(struct btf_verifier_env *env,
+			       const struct btf_type *t,
+			       u32 meta_left)
+{
+	const struct btf_enum *enums = btf_type_enum(t);
+	struct btf *btf = env->btf;
+	u16 i, nr_enums;
+	u32 meta_needed;
+
+	nr_enums = btf_type_vlen(t);
+	meta_needed = nr_enums * sizeof(*enums);
+
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	if (t->size > 8 || !is_power_of_2(t->size)) {
+		btf_verifier_log_type(env, t, "Unexpected size");
+		return -EINVAL;
+	}
+
+	/* enum type either no name or a valid one */
+	if (t->name_off &&
+	    !btf_name_valid_identifier(env->btf, t->name_off)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	for (i = 0; i < nr_enums; i++) {
+		if (!btf_name_offset_valid(btf, enums[i].name_off)) {
+			btf_verifier_log(env, "\tInvalid name_offset:%u",
+					 enums[i].name_off);
+			return -EINVAL;
+		}
+
+		/* enum member must have a valid name */
+		if (!enums[i].name_off ||
+		    !btf_name_valid_identifier(btf, enums[i].name_off)) {
+			btf_verifier_log_type(env, t, "Invalid name");
+			return -EINVAL;
+		}
+
+		if (env->log.level == BPF_LOG_KERNEL)
+			continue;
+		btf_verifier_log(env, "\t%s val=%d\n",
+				 __btf_name_by_offset(btf, enums[i].name_off),
+				 enums[i].val);
+	}
+
+	return meta_needed;
+}
+
+static void btf_enum_log(struct btf_verifier_env *env,
+			 const struct btf_type *t)
+{
+	btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
+}
+
+static void btf_enum_show(const struct btf *btf, const struct btf_type *t,
+			  u32 type_id, void *data, u8 bits_offset,
+			  struct btf_show *show)
+{
+	const struct btf_enum *enums = btf_type_enum(t);
+	u32 i, nr_enums = btf_type_vlen(t);
+	void *safe_data;
+	int v;
+
+	safe_data = btf_show_start_type(show, t, type_id, data);
+	if (!safe_data)
+		return;
+
+	v = *(int *)safe_data;
+
+	for (i = 0; i < nr_enums; i++) {
+		if (v != enums[i].val)
+			continue;
+
+		btf_show_type_value(show, "%s",
+				    __btf_name_by_offset(btf,
+							 enums[i].name_off));
+
+		btf_show_end_type(show);
+		return;
+	}
+
+	btf_show_type_value(show, "%d", v);
+	btf_show_end_type(show);
+}
+
+static struct btf_kind_operations enum_ops = {
+	.check_meta = btf_enum_check_meta,
+	.resolve = btf_df_resolve,
+	.check_member = btf_enum_check_member,
+	.check_kflag_member = btf_enum_check_kflag_member,
+	.log_details = btf_enum_log,
+	.show = btf_enum_show,
+};
+
+static s32 btf_func_proto_check_meta(struct btf_verifier_env *env,
+				     const struct btf_type *t,
+				     u32 meta_left)
+{
+	u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param);
+
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	if (t->name_off) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	return meta_needed;
+}
+
+static void btf_func_proto_log(struct btf_verifier_env *env,
+			       const struct btf_type *t)
+{
+	const struct btf_param *args = (const struct btf_param *)(t + 1);
+	u16 nr_args = btf_type_vlen(t), i;
+
+	btf_verifier_log(env, "return=%u args=(", t->type);
+	if (!nr_args) {
+		btf_verifier_log(env, "void");
+		goto done;
+	}
+
+	if (nr_args == 1 && !args[0].type) {
+		/* Only one vararg */
+		btf_verifier_log(env, "vararg");
+		goto done;
+	}
+
+	btf_verifier_log(env, "%u %s", args[0].type,
+			 __btf_name_by_offset(env->btf,
+					      args[0].name_off));
+	for (i = 1; i < nr_args - 1; i++)
+		btf_verifier_log(env, ", %u %s", args[i].type,
+				 __btf_name_by_offset(env->btf,
+						      args[i].name_off));
+
+	if (nr_args > 1) {
+		const struct btf_param *last_arg = &args[nr_args - 1];
+
+		if (last_arg->type)
+			btf_verifier_log(env, ", %u %s", last_arg->type,
+					 __btf_name_by_offset(env->btf,
+							      last_arg->name_off));
+		else
+			btf_verifier_log(env, ", vararg");
+	}
+
+done:
+	btf_verifier_log(env, ")");
+}
+
+static struct btf_kind_operations func_proto_ops = {
+	.check_meta = btf_func_proto_check_meta,
+	.resolve = btf_df_resolve,
+	/*
+	 * BTF_KIND_FUNC_PROTO cannot be directly referred by
+	 * a struct's member.
+	 *
+	 * It should be a funciton pointer instead.
+	 * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO)
+	 *
+	 * Hence, there is no btf_func_check_member().
+	 */
+	.check_member = btf_df_check_member,
+	.check_kflag_member = btf_df_check_kflag_member,
+	.log_details = btf_func_proto_log,
+	.show = btf_df_show,
+};
+
+static s32 btf_func_check_meta(struct btf_verifier_env *env,
+			       const struct btf_type *t,
+			       u32 meta_left)
+{
+	if (!t->name_off ||
+	    !btf_name_valid_identifier(env->btf, t->name_off)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
+		btf_verifier_log_type(env, t, "Invalid func linkage");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	return 0;
+}
+
+static struct btf_kind_operations func_ops = {
+	.check_meta = btf_func_check_meta,
+	.resolve = btf_df_resolve,
+	.check_member = btf_df_check_member,
+	.check_kflag_member = btf_df_check_kflag_member,
+	.log_details = btf_ref_type_log,
+	.show = btf_df_show,
+};
+
+static s32 btf_var_check_meta(struct btf_verifier_env *env,
+			      const struct btf_type *t,
+			      u32 meta_left)
+{
+	const struct btf_var *var;
+	u32 meta_needed = sizeof(*var);
+
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	if (btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen != 0");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	if (!t->name_off ||
+	    !__btf_name_valid(env->btf, t->name_off)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	/* A var cannot be in type void */
+	if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
+		btf_verifier_log_type(env, t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	var = btf_type_var(t);
+	if (var->linkage != BTF_VAR_STATIC &&
+	    var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
+		btf_verifier_log_type(env, t, "Linkage not supported");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	return meta_needed;
+}
+
+static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
+{
+	const struct btf_var *var = btf_type_var(t);
+
+	btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage);
+}
+
+static const struct btf_kind_operations var_ops = {
+	.check_meta		= btf_var_check_meta,
+	.resolve		= btf_var_resolve,
+	.check_member		= btf_df_check_member,
+	.check_kflag_member	= btf_df_check_kflag_member,
+	.log_details		= btf_var_log,
+	.show			= btf_var_show,
+};
+
+static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
+				  const struct btf_type *t,
+				  u32 meta_left)
+{
+	const struct btf_var_secinfo *vsi;
+	u64 last_vsi_end_off = 0, sum = 0;
+	u32 i, meta_needed;
+
+	meta_needed = btf_type_vlen(t) * sizeof(*vsi);
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	if (!btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen == 0");
+		return -EINVAL;
+	}
+
+	if (!t->size) {
+		btf_verifier_log_type(env, t, "size == 0");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	if (!t->name_off ||
+	    !btf_name_valid_section(env->btf, t->name_off)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	for_each_vsi(i, t, vsi) {
+		/* A var cannot be in type void */
+		if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid type_id");
+			return -EINVAL;
+		}
+
+		if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid offset");
+			return -EINVAL;
+		}
+
+		if (!vsi->size || vsi->size > t->size) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid size");
+			return -EINVAL;
+		}
+
+		last_vsi_end_off = vsi->offset + vsi->size;
+		if (last_vsi_end_off > t->size) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid offset+size");
+			return -EINVAL;
+		}
+
+		btf_verifier_log_vsi(env, t, vsi, NULL);
+		sum += vsi->size;
+	}
+
+	if (t->size < sum) {
+		btf_verifier_log_type(env, t, "Invalid btf_info size");
+		return -EINVAL;
+	}
+
+	return meta_needed;
+}
+
+static int btf_datasec_resolve(struct btf_verifier_env *env,
+			       const struct resolve_vertex *v)
+{
+	const struct btf_var_secinfo *vsi;
+	struct btf *btf = env->btf;
+	u16 i;
+
+	env->resolve_mode = RESOLVE_TBD;
+	for_each_vsi_from(i, v->next_member, v->t, vsi) {
+		u32 var_type_id = vsi->type, type_id, type_size = 0;
+		const struct btf_type *var_type = btf_type_by_id(env->btf,
+								 var_type_id);
+		if (!var_type || !btf_type_is_var(var_type)) {
+			btf_verifier_log_vsi(env, v->t, vsi,
+					     "Not a VAR kind member");
+			return -EINVAL;
+		}
+
+		if (!env_type_is_resolve_sink(env, var_type) &&
+		    !env_type_is_resolved(env, var_type_id)) {
+			env_stack_set_next_member(env, i + 1);
+			return env_stack_push(env, var_type, var_type_id);
+		}
+
+		type_id = var_type->type;
+		if (!btf_type_id_size(btf, &type_id, &type_size)) {
+			btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
+			return -EINVAL;
+		}
+
+		if (vsi->size < type_size) {
+			btf_verifier_log_vsi(env, v->t, vsi, "Invalid size");
+			return -EINVAL;
+		}
+	}
+
+	env_stack_pop_resolved(env, 0, 0);
+	return 0;
+}
+
+static void btf_datasec_log(struct btf_verifier_env *env,
+			    const struct btf_type *t)
+{
+	btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
+}
+
+static void btf_datasec_show(const struct btf *btf,
+			     const struct btf_type *t, u32 type_id,
+			     void *data, u8 bits_offset,
+			     struct btf_show *show)
+{
+	const struct btf_var_secinfo *vsi;
+	const struct btf_type *var;
+	u32 i;
+
+	if (!btf_show_start_type(show, t, type_id, data))
+		return;
+
+	btf_show_type_value(show, "section (\"%s\") = {",
+			    __btf_name_by_offset(btf, t->name_off));
+	for_each_vsi(i, t, vsi) {
+		var = btf_type_by_id(btf, vsi->type);
+		if (i)
+			btf_show(show, ",");
+		btf_type_ops(var)->show(btf, var, vsi->type,
+					data + vsi->offset, bits_offset, show);
+	}
+	btf_show_end_type(show);
+}
+
+static const struct btf_kind_operations datasec_ops = {
+	.check_meta		= btf_datasec_check_meta,
+	.resolve		= btf_datasec_resolve,
+	.check_member		= btf_df_check_member,
+	.check_kflag_member	= btf_df_check_kflag_member,
+	.log_details		= btf_datasec_log,
+	.show			= btf_datasec_show,
+};
+
+static int btf_func_proto_check(struct btf_verifier_env *env,
+				const struct btf_type *t)
+{
+	const struct btf_type *ret_type;
+	const struct btf_param *args;
+	const struct btf *btf;
+	u16 nr_args, i;
+	int err;
+
+	btf = env->btf;
+	args = (const struct btf_param *)(t + 1);
+	nr_args = btf_type_vlen(t);
+
+	/* Check func return type which could be "void" (t->type == 0) */
+	if (t->type) {
+		u32 ret_type_id = t->type;
+
+		ret_type = btf_type_by_id(btf, ret_type_id);
+		if (!ret_type) {
+			btf_verifier_log_type(env, t, "Invalid return type");
+			return -EINVAL;
+		}
+
+		if (btf_type_needs_resolve(ret_type) &&
+		    !env_type_is_resolved(env, ret_type_id)) {
+			err = btf_resolve(env, ret_type, ret_type_id);
+			if (err)
+				return err;
+		}
+
+		/* Ensure the return type is a type that has a size */
+		if (!btf_type_id_size(btf, &ret_type_id, NULL)) {
+			btf_verifier_log_type(env, t, "Invalid return type");
+			return -EINVAL;
+		}
+	}
+
+	if (!nr_args)
+		return 0;
+
+	/* Last func arg type_id could be 0 if it is a vararg */
+	if (!args[nr_args - 1].type) {
+		if (args[nr_args - 1].name_off) {
+			btf_verifier_log_type(env, t, "Invalid arg#%u",
+					      nr_args);
+			return -EINVAL;
+		}
+		nr_args--;
+	}
+
+	err = 0;
+	for (i = 0; i < nr_args; i++) {
+		const struct btf_type *arg_type;
+		u32 arg_type_id;
+
+		arg_type_id = args[i].type;
+		arg_type = btf_type_by_id(btf, arg_type_id);
+		if (!arg_type) {
+			btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+			err = -EINVAL;
+			break;
+		}
+
+		if (btf_type_is_resolve_source_only(arg_type)) {
+			btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+			return -EINVAL;
+		}
+
+		if (args[i].name_off &&
+		    (!btf_name_offset_valid(btf, args[i].name_off) ||
+		     !btf_name_valid_identifier(btf, args[i].name_off))) {
+			btf_verifier_log_type(env, t,
+					      "Invalid arg#%u", i + 1);
+			err = -EINVAL;
+			break;
+		}
+
+		if (btf_type_needs_resolve(arg_type) &&
+		    !env_type_is_resolved(env, arg_type_id)) {
+			err = btf_resolve(env, arg_type, arg_type_id);
+			if (err)
+				break;
+		}
+
+		if (!btf_type_id_size(btf, &arg_type_id, NULL)) {
+			btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+			err = -EINVAL;
+			break;
+		}
+	}
+
+	return err;
+}
+
+static int btf_func_check(struct btf_verifier_env *env,
+			  const struct btf_type *t)
+{
+	const struct btf_type *proto_type;
+	const struct btf_param *args;
+	const struct btf *btf;
+	u16 nr_args, i;
+
+	btf = env->btf;
+	proto_type = btf_type_by_id(btf, t->type);
+
+	if (!proto_type || !btf_type_is_func_proto(proto_type)) {
+		btf_verifier_log_type(env, t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	args = (const struct btf_param *)(proto_type + 1);
+	nr_args = btf_type_vlen(proto_type);
+	for (i = 0; i < nr_args; i++) {
+		if (!args[i].name_off && args[i].type) {
+			btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
+	[BTF_KIND_INT] = &int_ops,
+	[BTF_KIND_PTR] = &ptr_ops,
+	[BTF_KIND_ARRAY] = &array_ops,
+	[BTF_KIND_STRUCT] = &struct_ops,
+	[BTF_KIND_UNION] = &struct_ops,
+	[BTF_KIND_ENUM] = &enum_ops,
+	[BTF_KIND_FWD] = &fwd_ops,
+	[BTF_KIND_TYPEDEF] = &modifier_ops,
+	[BTF_KIND_VOLATILE] = &modifier_ops,
+	[BTF_KIND_CONST] = &modifier_ops,
+	[BTF_KIND_RESTRICT] = &modifier_ops,
+	[BTF_KIND_FUNC] = &func_ops,
+	[BTF_KIND_FUNC_PROTO] = &func_proto_ops,
+	[BTF_KIND_VAR] = &var_ops,
+	[BTF_KIND_DATASEC] = &datasec_ops,
+};
+
+static s32 btf_check_meta(struct btf_verifier_env *env,
+			  const struct btf_type *t,
+			  u32 meta_left)
+{
+	u32 saved_meta_left = meta_left;
+	s32 var_meta_size;
+
+	if (meta_left < sizeof(*t)) {
+		btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu",
+				 env->log_type_id, meta_left, sizeof(*t));
+		return -EINVAL;
+	}
+	meta_left -= sizeof(*t);
+
+	if (t->info & ~BTF_INFO_MASK) {
+		btf_verifier_log(env, "[%u] Invalid btf_info:%x",
+				 env->log_type_id, t->info);
+		return -EINVAL;
+	}
+
+	if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX ||
+	    BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) {
+		btf_verifier_log(env, "[%u] Invalid kind:%u",
+				 env->log_type_id, BTF_INFO_KIND(t->info));
+		return -EINVAL;
+	}
+
+	if (!btf_name_offset_valid(env->btf, t->name_off)) {
+		btf_verifier_log(env, "[%u] Invalid name_offset:%u",
+				 env->log_type_id, t->name_off);
+		return -EINVAL;
+	}
+
+	var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left);
+	if (var_meta_size < 0)
+		return var_meta_size;
+
+	meta_left -= var_meta_size;
+
+	return saved_meta_left - meta_left;
+}
+
+static int btf_check_all_metas(struct btf_verifier_env *env)
+{
+	struct btf *btf = env->btf;
+	struct btf_header *hdr;
+	void *cur, *end;
+
+	hdr = &btf->hdr;
+	cur = btf->nohdr_data + hdr->type_off;
+	end = cur + hdr->type_len;
+
+	env->log_type_id = 1;
+	while (cur < end) {
+		struct btf_type *t = cur;
+		s32 meta_size;
+
+		meta_size = btf_check_meta(env, t, end - cur);
+		if (meta_size < 0)
+			return meta_size;
+
+		btf_add_type(env, t);
+		cur += meta_size;
+		env->log_type_id++;
+	}
+
+	return 0;
+}
+
+static bool btf_resolve_valid(struct btf_verifier_env *env,
+			      const struct btf_type *t,
+			      u32 type_id)
+{
+	struct btf *btf = env->btf;
+
+	if (!env_type_is_resolved(env, type_id))
+		return false;
+
+	if (btf_type_is_struct(t) || btf_type_is_datasec(t))
+		return !btf->resolved_ids[type_id] &&
+		       !btf->resolved_sizes[type_id];
+
+	if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
+	    btf_type_is_var(t)) {
+		t = btf_type_id_resolve(btf, &type_id);
+		return t &&
+		       !btf_type_is_modifier(t) &&
+		       !btf_type_is_var(t) &&
+		       !btf_type_is_datasec(t);
+	}
+
+	if (btf_type_is_array(t)) {
+		const struct btf_array *array = btf_type_array(t);
+		const struct btf_type *elem_type;
+		u32 elem_type_id = array->type;
+		u32 elem_size;
+
+		elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
+		return elem_type && !btf_type_is_modifier(elem_type) &&
+			(array->nelems * elem_size ==
+			 btf->resolved_sizes[type_id]);
+	}
+
+	return false;
+}
+
+static int btf_resolve(struct btf_verifier_env *env,
+		       const struct btf_type *t, u32 type_id)
+{
+	u32 save_log_type_id = env->log_type_id;
+	const struct resolve_vertex *v;
+	int err = 0;
+
+	env->resolve_mode = RESOLVE_TBD;
+	env_stack_push(env, t, type_id);
+	while (!err && (v = env_stack_peak(env))) {
+		env->log_type_id = v->type_id;
+		err = btf_type_ops(v->t)->resolve(env, v);
+	}
+
+	env->log_type_id = type_id;
+	if (err == -E2BIG) {
+		btf_verifier_log_type(env, t,
+				      "Exceeded max resolving depth:%u",
+				      MAX_RESOLVE_DEPTH);
+	} else if (err == -EEXIST) {
+		btf_verifier_log_type(env, t, "Loop detected");
+	}
+
+	/* Final sanity check */
+	if (!err && !btf_resolve_valid(env, t, type_id)) {
+		btf_verifier_log_type(env, t, "Invalid resolve state");
+		err = -EINVAL;
+	}
+
+	env->log_type_id = save_log_type_id;
+	return err;
+}
+
+static int btf_check_all_types(struct btf_verifier_env *env)
+{
+	struct btf *btf = env->btf;
+	u32 type_id;
+	int err;
+
+	err = env_resolve_init(env);
+	if (err)
+		return err;
+
+	env->phase++;
+	for (type_id = 1; type_id <= btf->nr_types; type_id++) {
+		const struct btf_type *t = btf_type_by_id(btf, type_id);
+
+		env->log_type_id = type_id;
+		if (btf_type_needs_resolve(t) &&
+		    !env_type_is_resolved(env, type_id)) {
+			err = btf_resolve(env, t, type_id);
+			if (err)
+				return err;
+		}
+
+		if (btf_type_is_func_proto(t)) {
+			err = btf_func_proto_check(env, t);
+			if (err)
+				return err;
+		}
+
+		if (btf_type_is_func(t)) {
+			err = btf_func_check(env, t);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+static int btf_parse_type_sec(struct btf_verifier_env *env)
+{
+	const struct btf_header *hdr = &env->btf->hdr;
+	int err;
+
+	/* Type section must align to 4 bytes */
+	if (hdr->type_off & (sizeof(u32) - 1)) {
+		btf_verifier_log(env, "Unaligned type_off");
+		return -EINVAL;
+	}
+
+	if (!hdr->type_len) {
+		btf_verifier_log(env, "No type found");
+		return -EINVAL;
+	}
+
+	err = btf_check_all_metas(env);
+	if (err)
+		return err;
+
+	return btf_check_all_types(env);
+}
+
+static int btf_parse_str_sec(struct btf_verifier_env *env)
+{
+	const struct btf_header *hdr;
+	struct btf *btf = env->btf;
+	const char *start, *end;
+
+	hdr = &btf->hdr;
+	start = btf->nohdr_data + hdr->str_off;
+	end = start + hdr->str_len;
+
+	if (end != btf->data + btf->data_size) {
+		btf_verifier_log(env, "String section is not at the end");
+		return -EINVAL;
+	}
+
+	if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET ||
+	    start[0] || end[-1]) {
+		btf_verifier_log(env, "Invalid string section");
+		return -EINVAL;
+	}
+
+	btf->strings = start;
+
+	return 0;
+}
+
+static const size_t btf_sec_info_offset[] = {
+	offsetof(struct btf_header, type_off),
+	offsetof(struct btf_header, str_off),
+};
+
+static int btf_sec_info_cmp(const void *a, const void *b)
+{
+	const struct btf_sec_info *x = a;
+	const struct btf_sec_info *y = b;
+
+	return (int)(x->off - y->off) ? : (int)(x->len - y->len);
+}
+
+static int btf_check_sec_info(struct btf_verifier_env *env,
+			      u32 btf_data_size)
+{
+	struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)];
+	u32 total, expected_total, i;
+	const struct btf_header *hdr;
+	const struct btf *btf;
+
+	btf = env->btf;
+	hdr = &btf->hdr;
+
+	/* Populate the secs from hdr */
+	for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++)
+		secs[i] = *(struct btf_sec_info *)((void *)hdr +
+						   btf_sec_info_offset[i]);
+
+	sort(secs, ARRAY_SIZE(btf_sec_info_offset),
+	     sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL);
+
+	/* Check for gaps and overlap among sections */
+	total = 0;
+	expected_total = btf_data_size - hdr->hdr_len;
+	for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) {
+		if (expected_total < secs[i].off) {
+			btf_verifier_log(env, "Invalid section offset");
+			return -EINVAL;
+		}
+		if (total < secs[i].off) {
+			/* gap */
+			btf_verifier_log(env, "Unsupported section found");
+			return -EINVAL;
+		}
+		if (total > secs[i].off) {
+			btf_verifier_log(env, "Section overlap found");
+			return -EINVAL;
+		}
+		if (expected_total - total < secs[i].len) {
+			btf_verifier_log(env,
+					 "Total section length too long");
+			return -EINVAL;
+		}
+		total += secs[i].len;
+	}
+
+	/* There is data other than hdr and known sections */
+	if (expected_total != total) {
+		btf_verifier_log(env, "Unsupported section found");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int btf_parse_hdr(struct btf_verifier_env *env)
+{
+	u32 hdr_len, hdr_copy, btf_data_size;
+	const struct btf_header *hdr;
+	struct btf *btf;
+	int err;
+
+	btf = env->btf;
+	btf_data_size = btf->data_size;
+
+	if (btf_data_size <
+	    offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) {
+		btf_verifier_log(env, "hdr_len not found");
+		return -EINVAL;
+	}
+
+	hdr = btf->data;
+	hdr_len = hdr->hdr_len;
+	if (btf_data_size < hdr_len) {
+		btf_verifier_log(env, "btf_header not found");
+		return -EINVAL;
+	}
+
+	/* Ensure the unsupported header fields are zero */
+	if (hdr_len > sizeof(btf->hdr)) {
+		u8 *expected_zero = btf->data + sizeof(btf->hdr);
+		u8 *end = btf->data + hdr_len;
+
+		for (; expected_zero < end; expected_zero++) {
+			if (*expected_zero) {
+				btf_verifier_log(env, "Unsupported btf_header");
+				return -E2BIG;
+			}
+		}
+	}
+
+	hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
+	memcpy(&btf->hdr, btf->data, hdr_copy);
+
+	hdr = &btf->hdr;
+
+	btf_verifier_log_hdr(env, btf_data_size);
+
+	if (hdr->magic != BTF_MAGIC) {
+		btf_verifier_log(env, "Invalid magic");
+		return -EINVAL;
+	}
+
+	if (hdr->version != BTF_VERSION) {
+		btf_verifier_log(env, "Unsupported version");
+		return -ENOTSUPP;
+	}
+
+	if (hdr->flags) {
+		btf_verifier_log(env, "Unsupported flags");
+		return -ENOTSUPP;
+	}
+
+	if (btf_data_size == hdr->hdr_len) {
+		btf_verifier_log(env, "No data");
+		return -EINVAL;
+	}
+
+	err = btf_check_sec_info(env, btf_data_size);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size,
+			     u32 log_level, char __user *log_ubuf, u32 log_size)
+{
+	struct btf_verifier_env *env = NULL;
+	struct bpf_verifier_log *log;
+	struct btf *btf = NULL;
+	u8 *data;
+	int err;
+
+	if (btf_data_size > BTF_MAX_SIZE)
+		return ERR_PTR(-E2BIG);
+
+	env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
+	if (!env)
+		return ERR_PTR(-ENOMEM);
+
+	log = &env->log;
+	if (log_level || log_ubuf || log_size) {
+		/* user requested verbose verifier output
+		 * and supplied buffer to store the verification trace
+		 */
+		log->level = log_level;
+		log->ubuf = log_ubuf;
+		log->len_total = log_size;
+
+		/* log attributes have to be sane */
+		if (!bpf_verifier_log_attr_valid(log)) {
+			err = -EINVAL;
+			goto errout;
+		}
+	}
+
+	btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
+	if (!btf) {
+		err = -ENOMEM;
+		goto errout;
+	}
+	env->btf = btf;
+
+	data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN);
+	if (!data) {
+		err = -ENOMEM;
+		goto errout;
+	}
+
+	btf->data = data;
+	btf->data_size = btf_data_size;
+
+	if (copy_from_user(data, btf_data, btf_data_size)) {
+		err = -EFAULT;
+		goto errout;
+	}
+
+	err = btf_parse_hdr(env);
+	if (err)
+		goto errout;
+
+	btf->nohdr_data = btf->data + btf->hdr.hdr_len;
+
+	err = btf_parse_str_sec(env);
+	if (err)
+		goto errout;
+
+	err = btf_parse_type_sec(env);
+	if (err)
+		goto errout;
+
+	if (log->level && bpf_verifier_log_full(log)) {
+		err = -ENOSPC;
+		goto errout;
+	}
+
+	btf_verifier_env_free(env);
+	refcount_set(&btf->refcnt, 1);
+	return btf;
+
+errout:
+	btf_verifier_env_free(env);
+	if (btf)
+		btf_free(btf);
+	return ERR_PTR(err);
+}
+
+extern char __weak __start_BTF[];
+extern char __weak __stop_BTF[];
+extern struct btf *btf_vmlinux;
+
+#define BPF_MAP_TYPE(_id, _ops)
+#define BPF_LINK_TYPE(_id, _name)
+static union {
+	struct bpf_ctx_convert {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	prog_ctx_type _id##_prog; \
+	kern_ctx_type _id##_kern;
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+	} *__t;
+	/* 't' is written once under lock. Read many times. */
+	const struct btf_type *t;
+} bpf_ctx_convert;
+enum {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	__ctx_convert##_id,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+	__ctx_convert_unused, /* to avoid empty enum in extreme .config */
+};
+static u8 bpf_ctx_convert_map[] = {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	[_id] = __ctx_convert##_id,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+	0, /* avoid empty array */
+};
+#undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
+
+static const struct btf_member *
+btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
+		      const struct btf_type *t, enum bpf_prog_type prog_type,
+		      int arg)
+{
+	const struct btf_type *conv_struct;
+	const struct btf_type *ctx_struct;
+	const struct btf_member *ctx_type;
+	const char *tname, *ctx_tname;
+
+	conv_struct = bpf_ctx_convert.t;
+	if (!conv_struct) {
+		bpf_log(log, "btf_vmlinux is malformed\n");
+		return NULL;
+	}
+	t = btf_type_by_id(btf, t->type);
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (!btf_type_is_struct(t)) {
+		/* Only pointer to struct is supported for now.
+		 * That means that BPF_PROG_TYPE_TRACEPOINT with BTF
+		 * is not supported yet.
+		 * BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
+		 */
+		if (log->level & BPF_LOG_LEVEL)
+			bpf_log(log, "arg#%d type is not a struct\n", arg);
+		return NULL;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+	if (!tname) {
+		bpf_log(log, "arg#%d struct doesn't have a name\n", arg);
+		return NULL;
+	}
+	/* prog_type is valid bpf program type. No need for bounds check. */
+	ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
+	/* ctx_struct is a pointer to prog_ctx_type in vmlinux.
+	 * Like 'struct __sk_buff'
+	 */
+	ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
+	if (!ctx_struct)
+		/* should not happen */
+		return NULL;
+again:
+	ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
+	if (!ctx_tname) {
+		/* should not happen */
+		bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
+		return NULL;
+	}
+	/* only compare that prog's ctx type name is the same as
+	 * kernel expects. No need to compare field by field.
+	 * It's ok for bpf prog to do:
+	 * struct __sk_buff {};
+	 * int socket_filter_bpf_prog(struct __sk_buff *skb)
+	 * { // no fields of skb are ever used }
+	 */
+	if (strcmp(ctx_tname, tname)) {
+		/* bpf_user_pt_regs_t is a typedef, so resolve it to
+		 * underlying struct and check name again
+		 */
+		if (!btf_type_is_modifier(ctx_struct))
+			return NULL;
+		while (btf_type_is_modifier(ctx_struct))
+			ctx_struct = btf_type_by_id(btf_vmlinux, ctx_struct->type);
+		goto again;
+	}
+	return ctx_type;
+}
+
+static const struct bpf_map_ops * const btf_vmlinux_map_ops[] = {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
+#define BPF_LINK_TYPE(_id, _name)
+#define BPF_MAP_TYPE(_id, _ops) \
+	[_id] = &_ops,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+#undef BPF_LINK_TYPE
+#undef BPF_MAP_TYPE
+};
+
+static int btf_vmlinux_map_ids_init(const struct btf *btf,
+				    struct bpf_verifier_log *log)
+{
+	const struct bpf_map_ops *ops;
+	int i, btf_id;
+
+	for (i = 0; i < ARRAY_SIZE(btf_vmlinux_map_ops); ++i) {
+		ops = btf_vmlinux_map_ops[i];
+		if (!ops || (!ops->map_btf_name && !ops->map_btf_id))
+			continue;
+		if (!ops->map_btf_name || !ops->map_btf_id) {
+			bpf_log(log, "map type %d is misconfigured\n", i);
+			return -EINVAL;
+		}
+		btf_id = btf_find_by_name_kind(btf, ops->map_btf_name,
+					       BTF_KIND_STRUCT);
+		if (btf_id < 0)
+			return btf_id;
+		*ops->map_btf_id = btf_id;
+	}
+
+	return 0;
+}
+
+static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
+				     struct btf *btf,
+				     const struct btf_type *t,
+				     enum bpf_prog_type prog_type,
+				     int arg)
+{
+	const struct btf_member *prog_ctx_type, *kern_ctx_type;
+
+	prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
+	if (!prog_ctx_type)
+		return -ENOENT;
+	kern_ctx_type = prog_ctx_type + 1;
+	return kern_ctx_type->type;
+}
+
+BTF_ID_LIST(bpf_ctx_convert_btf_id)
+BTF_ID(struct, bpf_ctx_convert)
+
+struct btf *btf_parse_vmlinux(void)
+{
+	struct btf_verifier_env *env = NULL;
+	struct bpf_verifier_log *log;
+	struct btf *btf = NULL;
+	int err;
+
+	env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
+	if (!env)
+		return ERR_PTR(-ENOMEM);
+
+	log = &env->log;
+	log->level = BPF_LOG_KERNEL;
+
+	btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
+	if (!btf) {
+		err = -ENOMEM;
+		goto errout;
+	}
+	env->btf = btf;
+
+	btf->data = __start_BTF;
+	btf->data_size = __stop_BTF - __start_BTF;
+
+	err = btf_parse_hdr(env);
+	if (err)
+		goto errout;
+
+	btf->nohdr_data = btf->data + btf->hdr.hdr_len;
+
+	err = btf_parse_str_sec(env);
+	if (err)
+		goto errout;
+
+	err = btf_check_all_metas(env);
+	if (err)
+		goto errout;
+
+	/* btf_parse_vmlinux() runs under bpf_verifier_lock */
+	bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]);
+
+	/* find bpf map structs for map_ptr access checking */
+	err = btf_vmlinux_map_ids_init(btf, log);
+	if (err < 0)
+		goto errout;
+
+	bpf_struct_ops_init(btf, log);
+
+	btf_verifier_env_free(env);
+	refcount_set(&btf->refcnt, 1);
+	return btf;
+
+errout:
+	btf_verifier_env_free(env);
+	if (btf) {
+		kvfree(btf->types);
+		kfree(btf);
+	}
+	return ERR_PTR(err);
+}
+
+struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
+{
+	struct bpf_prog *tgt_prog = prog->aux->dst_prog;
+
+	if (tgt_prog) {
+		return tgt_prog->aux->btf;
+	} else {
+		return btf_vmlinux;
+	}
+}
+
+static bool is_string_ptr(struct btf *btf, const struct btf_type *t)
+{
+	/* t comes in already as a pointer */
+	t = btf_type_by_id(btf, t->type);
+
+	/* allow const */
+	if (BTF_INFO_KIND(t->info) == BTF_KIND_CONST)
+		t = btf_type_by_id(btf, t->type);
+
+	/* char, signed char, unsigned char */
+	return btf_type_is_int(t) && t->size == 1;
+}
+
+bool btf_ctx_access(int off, int size, enum bpf_access_type type,
+		    const struct bpf_prog *prog,
+		    struct bpf_insn_access_aux *info)
+{
+	const struct btf_type *t = prog->aux->attach_func_proto;
+	struct bpf_prog *tgt_prog = prog->aux->dst_prog;
+	struct btf *btf = bpf_prog_get_target_btf(prog);
+	const char *tname = prog->aux->attach_func_name;
+	struct bpf_verifier_log *log = info->log;
+	const struct btf_param *args;
+	u32 nr_args, arg;
+	int i, ret;
+
+	if (off % 8) {
+		bpf_log(log, "func '%s' offset %d is not multiple of 8\n",
+			tname, off);
+		return false;
+	}
+	arg = off / 8;
+	args = (const struct btf_param *)(t + 1);
+	/* if (t == NULL) Fall back to default BPF prog with 5 u64 arguments */
+	nr_args = t ? btf_type_vlen(t) : 5;
+	if (prog->aux->attach_btf_trace) {
+		/* skip first 'void *__data' argument in btf_trace_##name typedef */
+		args++;
+		nr_args--;
+	}
+
+	if (arg > nr_args) {
+		bpf_log(log, "func '%s' doesn't have %d-th argument\n",
+			tname, arg + 1);
+		return false;
+	}
+
+	if (arg == nr_args) {
+		switch (prog->expected_attach_type) {
+		case BPF_LSM_MAC:
+		case BPF_TRACE_FEXIT:
+			/* When LSM programs are attached to void LSM hooks
+			 * they use FEXIT trampolines and when attached to
+			 * int LSM hooks, they use MODIFY_RETURN trampolines.
+			 *
+			 * While the LSM programs are BPF_MODIFY_RETURN-like
+			 * the check:
+			 *
+			 *	if (ret_type != 'int')
+			 *		return -EINVAL;
+			 *
+			 * is _not_ done here. This is still safe as LSM hooks
+			 * have only void and int return types.
+			 */
+			if (!t)
+				return true;
+			t = btf_type_by_id(btf, t->type);
+			break;
+		case BPF_MODIFY_RETURN:
+			/* For now the BPF_MODIFY_RETURN can only be attached to
+			 * functions that return an int.
+			 */
+			if (!t)
+				return false;
+
+			t = btf_type_skip_modifiers(btf, t->type, NULL);
+			if (!btf_type_is_small_int(t)) {
+				bpf_log(log,
+					"ret type %s not allowed for fmod_ret\n",
+					btf_kind_str[BTF_INFO_KIND(t->info)]);
+				return false;
+			}
+			break;
+		default:
+			bpf_log(log, "func '%s' doesn't have %d-th argument\n",
+				tname, arg + 1);
+			return false;
+		}
+	} else {
+		if (!t)
+			/* Default prog with 5 args */
+			return true;
+		t = btf_type_by_id(btf, args[arg].type);
+	}
+
+	/* skip modifiers */
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (btf_type_is_small_int(t) || btf_type_is_enum(t))
+		/* accessing a scalar */
+		return true;
+	if (!btf_type_is_ptr(t)) {
+		bpf_log(log,
+			"func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n",
+			tname, arg,
+			__btf_name_by_offset(btf, t->name_off),
+			btf_kind_str[BTF_INFO_KIND(t->info)]);
+		return false;
+	}
+
+	/* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */
+	for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
+		const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
+
+		if (ctx_arg_info->offset == off &&
+		    (ctx_arg_info->reg_type == PTR_TO_RDONLY_BUF_OR_NULL ||
+		     ctx_arg_info->reg_type == PTR_TO_RDWR_BUF_OR_NULL)) {
+			info->reg_type = ctx_arg_info->reg_type;
+			return true;
+		}
+	}
+
+	if (t->type == 0)
+		/* This is a pointer to void.
+		 * It is the same as scalar from the verifier safety pov.
+		 * No further pointer walking is allowed.
+		 */
+		return true;
+
+	if (is_string_ptr(btf, t))
+		return true;
+
+	/* this is a pointer to another type */
+	for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
+		const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
+
+		if (ctx_arg_info->offset == off) {
+			info->reg_type = ctx_arg_info->reg_type;
+			info->btf_id = ctx_arg_info->btf_id;
+			return true;
+		}
+	}
+
+	info->reg_type = PTR_TO_BTF_ID;
+	if (tgt_prog) {
+		enum bpf_prog_type tgt_type;
+
+		if (tgt_prog->type == BPF_PROG_TYPE_EXT)
+			tgt_type = tgt_prog->aux->saved_dst_prog_type;
+		else
+			tgt_type = tgt_prog->type;
+
+		ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg);
+		if (ret > 0) {
+			info->btf_id = ret;
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+	info->btf_id = t->type;
+	t = btf_type_by_id(btf, t->type);
+	/* skip modifiers */
+	while (btf_type_is_modifier(t)) {
+		info->btf_id = t->type;
+		t = btf_type_by_id(btf, t->type);
+	}
+	if (!btf_type_is_struct(t)) {
+		bpf_log(log,
+			"func '%s' arg%d type %s is not a struct\n",
+			tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]);
+		return false;
+	}
+	bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n",
+		tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)],
+		__btf_name_by_offset(btf, t->name_off));
+	return true;
+}
+
+enum bpf_struct_walk_result {
+	/* < 0 error */
+	WALK_SCALAR = 0,
+	WALK_PTR,
+	WALK_STRUCT,
+};
+
+static int btf_struct_walk(struct bpf_verifier_log *log,
+			   const struct btf_type *t, int off, int size,
+			   u32 *next_btf_id)
+{
+	u32 i, moff, mtrue_end, msize = 0, total_nelems = 0;
+	const struct btf_type *mtype, *elem_type = NULL;
+	const struct btf_member *member;
+	const char *tname, *mname;
+	u32 vlen, elem_id, mid;
+
+again:
+	tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
+	if (!btf_type_is_struct(t)) {
+		bpf_log(log, "Type '%s' is not a struct\n", tname);
+		return -EINVAL;
+	}
+
+	vlen = btf_type_vlen(t);
+	if (off + size > t->size) {
+		/* If the last element is a variable size array, we may
+		 * need to relax the rule.
+		 */
+		struct btf_array *array_elem;
+
+		if (vlen == 0)
+			goto error;
+
+		member = btf_type_member(t) + vlen - 1;
+		mtype = btf_type_skip_modifiers(btf_vmlinux, member->type,
+						NULL);
+		if (!btf_type_is_array(mtype))
+			goto error;
+
+		array_elem = (struct btf_array *)(mtype + 1);
+		if (array_elem->nelems != 0)
+			goto error;
+
+		moff = btf_member_bit_offset(t, member) / 8;
+		if (off < moff)
+			goto error;
+
+		/* Only allow structure for now, can be relaxed for
+		 * other types later.
+		 */
+		t = btf_type_skip_modifiers(btf_vmlinux, array_elem->type,
+					    NULL);
+		if (!btf_type_is_struct(t))
+			goto error;
+
+		off = (off - moff) % t->size;
+		goto again;
+
+error:
+		bpf_log(log, "access beyond struct %s at off %u size %u\n",
+			tname, off, size);
+		return -EACCES;
+	}
+
+	for_each_member(i, t, member) {
+		/* offset of the field in bytes */
+		moff = btf_member_bit_offset(t, member) / 8;
+		if (off + size <= moff)
+			/* won't find anything, field is already too far */
+			break;
+
+		if (btf_member_bitfield_size(t, member)) {
+			u32 end_bit = btf_member_bit_offset(t, member) +
+				btf_member_bitfield_size(t, member);
+
+			/* off <= moff instead of off == moff because clang
+			 * does not generate a BTF member for anonymous
+			 * bitfield like the ":16" here:
+			 * struct {
+			 *	int :16;
+			 *	int x:8;
+			 * };
+			 */
+			if (off <= moff &&
+			    BITS_ROUNDUP_BYTES(end_bit) <= off + size)
+				return WALK_SCALAR;
+
+			/* off may be accessing a following member
+			 *
+			 * or
+			 *
+			 * Doing partial access at either end of this
+			 * bitfield.  Continue on this case also to
+			 * treat it as not accessing this bitfield
+			 * and eventually error out as field not
+			 * found to keep it simple.
+			 * It could be relaxed if there was a legit
+			 * partial access case later.
+			 */
+			continue;
+		}
+
+		/* In case of "off" is pointing to holes of a struct */
+		if (off < moff)
+			break;
+
+		/* type of the field */
+		mid = member->type;
+		mtype = btf_type_by_id(btf_vmlinux, member->type);
+		mname = __btf_name_by_offset(btf_vmlinux, member->name_off);
+
+		mtype = __btf_resolve_size(btf_vmlinux, mtype, &msize,
+					   &elem_type, &elem_id, &total_nelems,
+					   &mid);
+		if (IS_ERR(mtype)) {
+			bpf_log(log, "field %s doesn't have size\n", mname);
+			return -EFAULT;
+		}
+
+		mtrue_end = moff + msize;
+		if (off >= mtrue_end)
+			/* no overlap with member, keep iterating */
+			continue;
+
+		if (btf_type_is_array(mtype)) {
+			u32 elem_idx;
+
+			/* __btf_resolve_size() above helps to
+			 * linearize a multi-dimensional array.
+			 *
+			 * The logic here is treating an array
+			 * in a struct as the following way:
+			 *
+			 * struct outer {
+			 *	struct inner array[2][2];
+			 * };
+			 *
+			 * looks like:
+			 *
+			 * struct outer {
+			 *	struct inner array_elem0;
+			 *	struct inner array_elem1;
+			 *	struct inner array_elem2;
+			 *	struct inner array_elem3;
+			 * };
+			 *
+			 * When accessing outer->array[1][0], it moves
+			 * moff to "array_elem2", set mtype to
+			 * "struct inner", and msize also becomes
+			 * sizeof(struct inner).  Then most of the
+			 * remaining logic will fall through without
+			 * caring the current member is an array or
+			 * not.
+			 *
+			 * Unlike mtype/msize/moff, mtrue_end does not
+			 * change.  The naming difference ("_true") tells
+			 * that it is not always corresponding to
+			 * the current mtype/msize/moff.
+			 * It is the true end of the current
+			 * member (i.e. array in this case).  That
+			 * will allow an int array to be accessed like
+			 * a scratch space,
+			 * i.e. allow access beyond the size of
+			 *      the array's element as long as it is
+			 *      within the mtrue_end boundary.
+			 */
+
+			/* skip empty array */
+			if (moff == mtrue_end)
+				continue;
+
+			msize /= total_nelems;
+			elem_idx = (off - moff) / msize;
+			moff += elem_idx * msize;
+			mtype = elem_type;
+			mid = elem_id;
+		}
+
+		/* the 'off' we're looking for is either equal to start
+		 * of this field or inside of this struct
+		 */
+		if (btf_type_is_struct(mtype)) {
+			/* our field must be inside that union or struct */
+			t = mtype;
+
+			/* return if the offset matches the member offset */
+			if (off == moff) {
+				*next_btf_id = mid;
+				return WALK_STRUCT;
+			}
+
+			/* adjust offset we're looking for */
+			off -= moff;
+			goto again;
+		}
+
+		if (btf_type_is_ptr(mtype)) {
+			const struct btf_type *stype;
+			u32 id;
+
+			if (msize != size || off != moff) {
+				bpf_log(log,
+					"cannot access ptr member %s with moff %u in struct %s with off %u size %u\n",
+					mname, moff, tname, off, size);
+				return -EACCES;
+			}
+			stype = btf_type_skip_modifiers(btf_vmlinux, mtype->type, &id);
+			if (btf_type_is_struct(stype)) {
+				*next_btf_id = id;
+				return WALK_PTR;
+			}
+		}
+
+		/* Allow more flexible access within an int as long as
+		 * it is within mtrue_end.
+		 * Since mtrue_end could be the end of an array,
+		 * that also allows using an array of int as a scratch
+		 * space. e.g. skb->cb[].
+		 */
+		if (off + size > mtrue_end) {
+			bpf_log(log,
+				"access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
+				mname, mtrue_end, tname, off, size);
+			return -EACCES;
+		}
+
+		return WALK_SCALAR;
+	}
+	bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off);
+	return -EINVAL;
+}
+
+int btf_struct_access(struct bpf_verifier_log *log,
+		      const struct btf_type *t, int off, int size,
+		      enum bpf_access_type atype __maybe_unused,
+		      u32 *next_btf_id)
+{
+	int err;
+	u32 id;
+
+	do {
+		err = btf_struct_walk(log, t, off, size, &id);
+
+		switch (err) {
+		case WALK_PTR:
+			/* If we found the pointer or scalar on t+off,
+			 * we're done.
+			 */
+			*next_btf_id = id;
+			return PTR_TO_BTF_ID;
+		case WALK_SCALAR:
+			return SCALAR_VALUE;
+		case WALK_STRUCT:
+			/* We found nested struct, so continue the search
+			 * by diving in it. At this point the offset is
+			 * aligned with the new type, so set it to 0.
+			 */
+			t = btf_type_by_id(btf_vmlinux, id);
+			off = 0;
+			break;
+		default:
+			/* It's either error or unknown return value..
+			 * scream and leave.
+			 */
+			if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value"))
+				return -EINVAL;
+			return err;
+		}
+	} while (t);
+
+	return -EINVAL;
+}
+
+bool btf_struct_ids_match(struct bpf_verifier_log *log,
+			  int off, u32 id, u32 need_type_id)
+{
+	const struct btf_type *type;
+	int err;
+
+	/* Are we already done? */
+	if (need_type_id == id && off == 0)
+		return true;
+
+again:
+	type = btf_type_by_id(btf_vmlinux, id);
+	if (!type)
+		return false;
+	err = btf_struct_walk(log, type, off, 1, &id);
+	if (err != WALK_STRUCT)
+		return false;
+
+	/* We found nested struct object. If it matches
+	 * the requested ID, we're done. Otherwise let's
+	 * continue the search with offset 0 in the new
+	 * type.
+	 */
+	if (need_type_id != id) {
+		off = 0;
+		goto again;
+	}
+
+	return true;
+}
+
+static int __get_type_size(struct btf *btf, u32 btf_id,
+			   const struct btf_type **bad_type)
+{
+	const struct btf_type *t;
+
+	if (!btf_id)
+		/* void */
+		return 0;
+	t = btf_type_by_id(btf, btf_id);
+	while (t && btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (!t) {
+		*bad_type = btf->types[0];
+		return -EINVAL;
+	}
+	if (btf_type_is_ptr(t))
+		/* kernel size of pointer. Not BPF's size of pointer*/
+		return sizeof(void *);
+	if (btf_type_is_int(t) || btf_type_is_enum(t))
+		return t->size;
+	*bad_type = t;
+	return -EINVAL;
+}
+
+int btf_distill_func_proto(struct bpf_verifier_log *log,
+			   struct btf *btf,
+			   const struct btf_type *func,
+			   const char *tname,
+			   struct btf_func_model *m)
+{
+	const struct btf_param *args;
+	const struct btf_type *t;
+	u32 i, nargs;
+	int ret;
+
+	if (!func) {
+		/* BTF function prototype doesn't match the verifier types.
+		 * Fall back to 5 u64 args.
+		 */
+		for (i = 0; i < 5; i++)
+			m->arg_size[i] = 8;
+		m->ret_size = 8;
+		m->nr_args = 5;
+		return 0;
+	}
+	args = (const struct btf_param *)(func + 1);
+	nargs = btf_type_vlen(func);
+	if (nargs >= MAX_BPF_FUNC_ARGS) {
+		bpf_log(log,
+			"The function %s has %d arguments. Too many.\n",
+			tname, nargs);
+		return -EINVAL;
+	}
+	ret = __get_type_size(btf, func->type, &t);
+	if (ret < 0) {
+		bpf_log(log,
+			"The function %s return type %s is unsupported.\n",
+			tname, btf_kind_str[BTF_INFO_KIND(t->info)]);
+		return -EINVAL;
+	}
+	m->ret_size = ret;
+
+	for (i = 0; i < nargs; i++) {
+		if (i == nargs - 1 && args[i].type == 0) {
+			bpf_log(log,
+				"The function %s with variable args is unsupported.\n",
+				tname);
+			return -EINVAL;
+		}
+		ret = __get_type_size(btf, args[i].type, &t);
+		if (ret < 0) {
+			bpf_log(log,
+				"The function %s arg%d type %s is unsupported.\n",
+				tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]);
+			return -EINVAL;
+		}
+		if (ret == 0) {
+			bpf_log(log,
+				"The function %s has malformed void argument.\n",
+				tname);
+			return -EINVAL;
+		}
+		m->arg_size[i] = ret;
+	}
+	m->nr_args = nargs;
+	return 0;
+}
+
+/* Compare BTFs of two functions assuming only scalars and pointers to context.
+ * t1 points to BTF_KIND_FUNC in btf1
+ * t2 points to BTF_KIND_FUNC in btf2
+ * Returns:
+ * EINVAL - function prototype mismatch
+ * EFAULT - verifier bug
+ * 0 - 99% match. The last 1% is validated by the verifier.
+ */
+static int btf_check_func_type_match(struct bpf_verifier_log *log,
+				     struct btf *btf1, const struct btf_type *t1,
+				     struct btf *btf2, const struct btf_type *t2)
+{
+	const struct btf_param *args1, *args2;
+	const char *fn1, *fn2, *s1, *s2;
+	u32 nargs1, nargs2, i;
+
+	fn1 = btf_name_by_offset(btf1, t1->name_off);
+	fn2 = btf_name_by_offset(btf2, t2->name_off);
+
+	if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) {
+		bpf_log(log, "%s() is not a global function\n", fn1);
+		return -EINVAL;
+	}
+	if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) {
+		bpf_log(log, "%s() is not a global function\n", fn2);
+		return -EINVAL;
+	}
+
+	t1 = btf_type_by_id(btf1, t1->type);
+	if (!t1 || !btf_type_is_func_proto(t1))
+		return -EFAULT;
+	t2 = btf_type_by_id(btf2, t2->type);
+	if (!t2 || !btf_type_is_func_proto(t2))
+		return -EFAULT;
+
+	args1 = (const struct btf_param *)(t1 + 1);
+	nargs1 = btf_type_vlen(t1);
+	args2 = (const struct btf_param *)(t2 + 1);
+	nargs2 = btf_type_vlen(t2);
+
+	if (nargs1 != nargs2) {
+		bpf_log(log, "%s() has %d args while %s() has %d args\n",
+			fn1, nargs1, fn2, nargs2);
+		return -EINVAL;
+	}
+
+	t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
+	t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
+	if (t1->info != t2->info) {
+		bpf_log(log,
+			"Return type %s of %s() doesn't match type %s of %s()\n",
+			btf_type_str(t1), fn1,
+			btf_type_str(t2), fn2);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < nargs1; i++) {
+		t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL);
+		t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL);
+
+		if (t1->info != t2->info) {
+			bpf_log(log, "arg%d in %s() is %s while %s() has %s\n",
+				i, fn1, btf_type_str(t1),
+				fn2, btf_type_str(t2));
+			return -EINVAL;
+		}
+		if (btf_type_has_size(t1) && t1->size != t2->size) {
+			bpf_log(log,
+				"arg%d in %s() has size %d while %s() has %d\n",
+				i, fn1, t1->size,
+				fn2, t2->size);
+			return -EINVAL;
+		}
+
+		/* global functions are validated with scalars and pointers
+		 * to context only. And only global functions can be replaced.
+		 * Hence type check only those types.
+		 */
+		if (btf_type_is_int(t1) || btf_type_is_enum(t1))
+			continue;
+		if (!btf_type_is_ptr(t1)) {
+			bpf_log(log,
+				"arg%d in %s() has unrecognized type\n",
+				i, fn1);
+			return -EINVAL;
+		}
+		t1 = btf_type_skip_modifiers(btf1, t1->type, NULL);
+		t2 = btf_type_skip_modifiers(btf2, t2->type, NULL);
+		if (!btf_type_is_struct(t1)) {
+			bpf_log(log,
+				"arg%d in %s() is not a pointer to context\n",
+				i, fn1);
+			return -EINVAL;
+		}
+		if (!btf_type_is_struct(t2)) {
+			bpf_log(log,
+				"arg%d in %s() is not a pointer to context\n",
+				i, fn2);
+			return -EINVAL;
+		}
+		/* This is an optional check to make program writing easier.
+		 * Compare names of structs and report an error to the user.
+		 * btf_prepare_func_args() already checked that t2 struct
+		 * is a context type. btf_prepare_func_args() will check
+		 * later that t1 struct is a context type as well.
+		 */
+		s1 = btf_name_by_offset(btf1, t1->name_off);
+		s2 = btf_name_by_offset(btf2, t2->name_off);
+		if (strcmp(s1, s2)) {
+			bpf_log(log,
+				"arg%d %s(struct %s *) doesn't match %s(struct %s *)\n",
+				i, fn1, s1, fn2, s2);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+/* Compare BTFs of given program with BTF of target program */
+int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog,
+			 struct btf *btf2, const struct btf_type *t2)
+{
+	struct btf *btf1 = prog->aux->btf;
+	const struct btf_type *t1;
+	u32 btf_id = 0;
+
+	if (!prog->aux->func_info) {
+		bpf_log(log, "Program extension requires BTF\n");
+		return -EINVAL;
+	}
+
+	btf_id = prog->aux->func_info[0].type_id;
+	if (!btf_id)
+		return -EFAULT;
+
+	t1 = btf_type_by_id(btf1, btf_id);
+	if (!t1 || !btf_type_is_func(t1))
+		return -EFAULT;
+
+	return btf_check_func_type_match(log, btf1, t1, btf2, t2);
+}
+
+/* Compare BTF of a function with given bpf_reg_state.
+ * Returns:
+ * EFAULT - there is a verifier bug. Abort verification.
+ * EINVAL - there is a type mismatch or BTF is not available.
+ * 0 - BTF matches with what bpf_reg_state expects.
+ * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
+ */
+int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
+			     struct bpf_reg_state *reg)
+{
+	struct bpf_verifier_log *log = &env->log;
+	struct bpf_prog *prog = env->prog;
+	struct btf *btf = prog->aux->btf;
+	const struct btf_param *args;
+	const struct btf_type *t;
+	u32 i, nargs, btf_id;
+	const char *tname;
+
+	if (!prog->aux->func_info)
+		return -EINVAL;
+
+	btf_id = prog->aux->func_info[subprog].type_id;
+	if (!btf_id)
+		return -EFAULT;
+
+	if (prog->aux->func_info_aux[subprog].unreliable)
+		return -EINVAL;
+
+	t = btf_type_by_id(btf, btf_id);
+	if (!t || !btf_type_is_func(t)) {
+		/* These checks were already done by the verifier while loading
+		 * struct bpf_func_info
+		 */
+		bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
+			subprog);
+		return -EFAULT;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+
+	t = btf_type_by_id(btf, t->type);
+	if (!t || !btf_type_is_func_proto(t)) {
+		bpf_log(log, "Invalid BTF of func %s\n", tname);
+		return -EFAULT;
+	}
+	args = (const struct btf_param *)(t + 1);
+	nargs = btf_type_vlen(t);
+	if (nargs > 5) {
+		bpf_log(log, "Function %s has %d > 5 args\n", tname, nargs);
+		goto out;
+	}
+	/* check that BTF function arguments match actual types that the
+	 * verifier sees.
+	 */
+	for (i = 0; i < nargs; i++) {
+		t = btf_type_by_id(btf, args[i].type);
+		while (btf_type_is_modifier(t))
+			t = btf_type_by_id(btf, t->type);
+		if (btf_type_is_int(t) || btf_type_is_enum(t)) {
+			if (reg[i + 1].type == SCALAR_VALUE)
+				continue;
+			bpf_log(log, "R%d is not a scalar\n", i + 1);
+			goto out;
+		}
+		if (btf_type_is_ptr(t)) {
+			if (reg[i + 1].type == SCALAR_VALUE) {
+				bpf_log(log, "R%d is not a pointer\n", i + 1);
+				goto out;
+			}
+			/* If function expects ctx type in BTF check that caller
+			 * is passing PTR_TO_CTX.
+			 */
+			if (btf_get_prog_ctx_type(log, btf, t, prog->type, i)) {
+				if (reg[i + 1].type != PTR_TO_CTX) {
+					bpf_log(log,
+						"arg#%d expected pointer to ctx, but got %s\n",
+						i, btf_kind_str[BTF_INFO_KIND(t->info)]);
+					goto out;
+				}
+				if (check_ctx_reg(env, &reg[i + 1], i + 1))
+					goto out;
+				continue;
+			}
+		}
+		bpf_log(log, "Unrecognized arg#%d type %s\n",
+			i, btf_kind_str[BTF_INFO_KIND(t->info)]);
+		goto out;
+	}
+	return 0;
+out:
+	/* Compiler optimizations can remove arguments from static functions
+	 * or mismatched type can be passed into a global function.
+	 * In such cases mark the function as unreliable from BTF point of view.
+	 */
+	prog->aux->func_info_aux[subprog].unreliable = true;
+	return -EINVAL;
+}
+
+/* Convert BTF of a function into bpf_reg_state if possible
+ * Returns:
+ * EFAULT - there is a verifier bug. Abort verification.
+ * EINVAL - cannot convert BTF.
+ * 0 - Successfully converted BTF into bpf_reg_state
+ * (either PTR_TO_CTX or SCALAR_VALUE).
+ */
+int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
+			  struct bpf_reg_state *reg)
+{
+	struct bpf_verifier_log *log = &env->log;
+	struct bpf_prog *prog = env->prog;
+	enum bpf_prog_type prog_type = prog->type;
+	struct btf *btf = prog->aux->btf;
+	const struct btf_param *args;
+	const struct btf_type *t;
+	u32 i, nargs, btf_id;
+	const char *tname;
+
+	if (!prog->aux->func_info ||
+	    prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) {
+		bpf_log(log, "Verifier bug\n");
+		return -EFAULT;
+	}
+
+	btf_id = prog->aux->func_info[subprog].type_id;
+	if (!btf_id) {
+		bpf_log(log, "Global functions need valid BTF\n");
+		return -EFAULT;
+	}
+
+	t = btf_type_by_id(btf, btf_id);
+	if (!t || !btf_type_is_func(t)) {
+		/* These checks were already done by the verifier while loading
+		 * struct bpf_func_info
+		 */
+		bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n",
+			subprog);
+		return -EFAULT;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+
+	if (log->level & BPF_LOG_LEVEL)
+		bpf_log(log, "Validating %s() func#%d...\n",
+			tname, subprog);
+
+	if (prog->aux->func_info_aux[subprog].unreliable) {
+		bpf_log(log, "Verifier bug in function %s()\n", tname);
+		return -EFAULT;
+	}
+	if (prog_type == BPF_PROG_TYPE_EXT)
+		prog_type = prog->aux->dst_prog->type;
+
+	t = btf_type_by_id(btf, t->type);
+	if (!t || !btf_type_is_func_proto(t)) {
+		bpf_log(log, "Invalid type of function %s()\n", tname);
+		return -EFAULT;
+	}
+	args = (const struct btf_param *)(t + 1);
+	nargs = btf_type_vlen(t);
+	if (nargs > 5) {
+		bpf_log(log, "Global function %s() with %d > 5 args. Buggy compiler.\n",
+			tname, nargs);
+		return -EINVAL;
+	}
+	/* check that function returns int */
+	t = btf_type_by_id(btf, t->type);
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (!btf_type_is_int(t) && !btf_type_is_enum(t)) {
+		bpf_log(log,
+			"Global function %s() doesn't return scalar. Only those are supported.\n",
+			tname);
+		return -EINVAL;
+	}
+	/* Convert BTF function arguments into verifier types.
+	 * Only PTR_TO_CTX and SCALAR are supported atm.
+	 */
+	for (i = 0; i < nargs; i++) {
+		t = btf_type_by_id(btf, args[i].type);
+		while (btf_type_is_modifier(t))
+			t = btf_type_by_id(btf, t->type);
+		if (btf_type_is_int(t) || btf_type_is_enum(t)) {
+			reg[i + 1].type = SCALAR_VALUE;
+			continue;
+		}
+		if (btf_type_is_ptr(t) &&
+		    btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
+			reg[i + 1].type = PTR_TO_CTX;
+			continue;
+		}
+		bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",
+			i, btf_kind_str[BTF_INFO_KIND(t->info)], tname);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void btf_type_show(const struct btf *btf, u32 type_id, void *obj,
+			  struct btf_show *show)
+{
+	const struct btf_type *t = btf_type_by_id(btf, type_id);
+
+	show->btf = btf;
+	memset(&show->state, 0, sizeof(show->state));
+	memset(&show->obj, 0, sizeof(show->obj));
+
+	btf_type_ops(t)->show(btf, t, type_id, obj, 0, show);
+}
+
+static void btf_seq_show(struct btf_show *show, const char *fmt,
+			 va_list args)
+{
+	seq_vprintf((struct seq_file *)show->target, fmt, args);
+}
+
+int btf_type_seq_show_flags(const struct btf *btf, u32 type_id,
+			    void *obj, struct seq_file *m, u64 flags)
+{
+	struct btf_show sseq;
+
+	sseq.target = m;
+	sseq.showfn = btf_seq_show;
+	sseq.flags = flags;
+
+	btf_type_show(btf, type_id, obj, &sseq);
+
+	return sseq.state.status;
+}
+
+void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
+		       struct seq_file *m)
+{
+	(void) btf_type_seq_show_flags(btf, type_id, obj, m,
+				       BTF_SHOW_NONAME | BTF_SHOW_COMPACT |
+				       BTF_SHOW_ZERO | BTF_SHOW_UNSAFE);
+}
+
+struct btf_show_snprintf {
+	struct btf_show show;
+	int len_left;		/* space left in string */
+	int len;		/* length we would have written */
+};
+
+static void btf_snprintf_show(struct btf_show *show, const char *fmt,
+			      va_list args)
+{
+	struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show;
+	int len;
+
+	len = vsnprintf(show->target, ssnprintf->len_left, fmt, args);
+
+	if (len < 0) {
+		ssnprintf->len_left = 0;
+		ssnprintf->len = len;
+	} else if (len > ssnprintf->len_left) {
+		/* no space, drive on to get length we would have written */
+		ssnprintf->len_left = 0;
+		ssnprintf->len += len;
+	} else {
+		ssnprintf->len_left -= len;
+		ssnprintf->len += len;
+		show->target += len;
+	}
+}
+
+int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
+			   char *buf, int len, u64 flags)
+{
+	struct btf_show_snprintf ssnprintf;
+
+	ssnprintf.show.target = buf;
+	ssnprintf.show.flags = flags;
+	ssnprintf.show.showfn = btf_snprintf_show;
+	ssnprintf.len_left = len;
+	ssnprintf.len = 0;
+
+	btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf);
+
+	/* If we encontered an error, return it. */
+	if (ssnprintf.show.state.status)
+		return ssnprintf.show.state.status;
+
+	/* Otherwise return length we would have written */
+	return ssnprintf.len;
+}
+
+#ifdef CONFIG_PROC_FS
+static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp)
+{
+	const struct btf *btf = filp->private_data;
+
+	seq_printf(m, "btf_id:\t%u\n", btf->id);
+}
+#endif
+
+static int btf_release(struct inode *inode, struct file *filp)
+{
+	btf_put(filp->private_data);
+	return 0;
+}
+
+const struct file_operations btf_fops = {
+#ifdef CONFIG_PROC_FS
+	.show_fdinfo	= bpf_btf_show_fdinfo,
+#endif
+	.release	= btf_release,
+};
+
+static int __btf_new_fd(struct btf *btf)
+{
+	return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC);
+}
+
+int btf_new_fd(const union bpf_attr *attr)
+{
+	struct btf *btf;
+	int ret;
+
+	btf = btf_parse(u64_to_user_ptr(attr->btf),
+			attr->btf_size, attr->btf_log_level,
+			u64_to_user_ptr(attr->btf_log_buf),
+			attr->btf_log_size);
+	if (IS_ERR(btf))
+		return PTR_ERR(btf);
+
+	ret = btf_alloc_id(btf);
+	if (ret) {
+		btf_free(btf);
+		return ret;
+	}
+
+	/*
+	 * The BTF ID is published to the userspace.
+	 * All BTF free must go through call_rcu() from
+	 * now on (i.e. free by calling btf_put()).
+	 */
+
+	ret = __btf_new_fd(btf);
+	if (ret < 0)
+		btf_put(btf);
+
+	return ret;
+}
+
+struct btf *btf_get_by_fd(int fd)
+{
+	struct btf *btf;
+	struct fd f;
+
+	f = fdget(fd);
+
+	if (!f.file)
+		return ERR_PTR(-EBADF);
+
+	if (f.file->f_op != &btf_fops) {
+		fdput(f);
+		return ERR_PTR(-EINVAL);
+	}
+
+	btf = f.file->private_data;
+	refcount_inc(&btf->refcnt);
+	fdput(f);
+
+	return btf;
+}
+
+int btf_get_info_by_fd(const struct btf *btf,
+		       const union bpf_attr *attr,
+		       union bpf_attr __user *uattr)
+{
+	struct bpf_btf_info __user *uinfo;
+	struct bpf_btf_info info;
+	u32 info_copy, btf_copy;
+	void __user *ubtf;
+	u32 uinfo_len;
+
+	uinfo = u64_to_user_ptr(attr->info.info);
+	uinfo_len = attr->info.info_len;
+
+	info_copy = min_t(u32, uinfo_len, sizeof(info));
+	memset(&info, 0, sizeof(info));
+	if (copy_from_user(&info, uinfo, info_copy))
+		return -EFAULT;
+
+	info.id = btf->id;
+	ubtf = u64_to_user_ptr(info.btf);
+	btf_copy = min_t(u32, btf->data_size, info.btf_size);
+	if (copy_to_user(ubtf, btf->data, btf_copy))
+		return -EFAULT;
+	info.btf_size = btf->data_size;
+
+	if (copy_to_user(uinfo, &info, info_copy) ||
+	    put_user(info_copy, &uattr->info.info_len))
+		return -EFAULT;
+
+	return 0;
+}
+
+int btf_get_fd_by_id(u32 id)
+{
+	struct btf *btf;
+	int fd;
+
+	rcu_read_lock();
+	btf = idr_find(&btf_idr, id);
+	if (!btf || !refcount_inc_not_zero(&btf->refcnt))
+		btf = ERR_PTR(-ENOENT);
+	rcu_read_unlock();
+
+	if (IS_ERR(btf))
+		return PTR_ERR(btf);
+
+	fd = __btf_new_fd(btf);
+	if (fd < 0)
+		btf_put(btf);
+
+	return fd;
+}
+
+u32 btf_id(const struct btf *btf)
+{
+	return btf->id;
+}
+
+static int btf_id_cmp_func(const void *a, const void *b)
+{
+	const int *pa = a, *pb = b;
+
+	return *pa - *pb;
+}
+
+bool btf_id_set_contains(const struct btf_id_set *set, u32 id)
+{
+	return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL;
+}
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
new file mode 100644
index 000000000..85927c2aa
--- /dev/null
+++ b/kernel/bpf/cgroup.c
@@ -0,0 +1,2014 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Functions to manage eBPF programs attached to cgroups
+ *
+ * Copyright (c) 2016 Daniel Mack
+ */
+
+#include <linux/kernel.h>
+#include <linux/atomic.h>
+#include <linux/cgroup.h>
+#include <linux/filter.h>
+#include <linux/slab.h>
+#include <linux/sysctl.h>
+#include <linux/string.h>
+#include <linux/bpf.h>
+#include <linux/bpf-cgroup.h>
+#include <net/sock.h>
+#include <net/bpf_sk_storage.h>
+
+#include "../cgroup/cgroup-internal.h"
+
+DEFINE_STATIC_KEY_FALSE(cgroup_bpf_enabled_key);
+EXPORT_SYMBOL(cgroup_bpf_enabled_key);
+
+void cgroup_bpf_offline(struct cgroup *cgrp)
+{
+	cgroup_get(cgrp);
+	percpu_ref_kill(&cgrp->bpf.refcnt);
+}
+
+static void bpf_cgroup_storages_free(struct bpf_cgroup_storage *storages[])
+{
+	enum bpf_cgroup_storage_type stype;
+
+	for_each_cgroup_storage_type(stype)
+		bpf_cgroup_storage_free(storages[stype]);
+}
+
+static int bpf_cgroup_storages_alloc(struct bpf_cgroup_storage *storages[],
+				     struct bpf_cgroup_storage *new_storages[],
+				     enum bpf_attach_type type,
+				     struct bpf_prog *prog,
+				     struct cgroup *cgrp)
+{
+	enum bpf_cgroup_storage_type stype;
+	struct bpf_cgroup_storage_key key;
+	struct bpf_map *map;
+
+	key.cgroup_inode_id = cgroup_id(cgrp);
+	key.attach_type = type;
+
+	for_each_cgroup_storage_type(stype) {
+		map = prog->aux->cgroup_storage[stype];
+		if (!map)
+			continue;
+
+		storages[stype] = cgroup_storage_lookup((void *)map, &key, false);
+		if (storages[stype])
+			continue;
+
+		storages[stype] = bpf_cgroup_storage_alloc(prog, stype);
+		if (IS_ERR(storages[stype])) {
+			bpf_cgroup_storages_free(new_storages);
+			return -ENOMEM;
+		}
+
+		new_storages[stype] = storages[stype];
+	}
+
+	return 0;
+}
+
+static void bpf_cgroup_storages_assign(struct bpf_cgroup_storage *dst[],
+				       struct bpf_cgroup_storage *src[])
+{
+	enum bpf_cgroup_storage_type stype;
+
+	for_each_cgroup_storage_type(stype)
+		dst[stype] = src[stype];
+}
+
+static void bpf_cgroup_storages_link(struct bpf_cgroup_storage *storages[],
+				     struct cgroup *cgrp,
+				     enum bpf_attach_type attach_type)
+{
+	enum bpf_cgroup_storage_type stype;
+
+	for_each_cgroup_storage_type(stype)
+		bpf_cgroup_storage_link(storages[stype], cgrp, attach_type);
+}
+
+/* Called when bpf_cgroup_link is auto-detached from dying cgroup.
+ * It drops cgroup and bpf_prog refcounts, and marks bpf_link as defunct. It
+ * doesn't free link memory, which will eventually be done by bpf_link's
+ * release() callback, when its last FD is closed.
+ */
+static void bpf_cgroup_link_auto_detach(struct bpf_cgroup_link *link)
+{
+	cgroup_put(link->cgroup);
+	link->cgroup = NULL;
+}
+
+/**
+ * cgroup_bpf_release() - put references of all bpf programs and
+ *                        release all cgroup bpf data
+ * @work: work structure embedded into the cgroup to modify
+ */
+static void cgroup_bpf_release(struct work_struct *work)
+{
+	struct cgroup *p, *cgrp = container_of(work, struct cgroup,
+					       bpf.release_work);
+	struct bpf_prog_array *old_array;
+	struct list_head *storages = &cgrp->bpf.storages;
+	struct bpf_cgroup_storage *storage, *stmp;
+
+	unsigned int type;
+
+	mutex_lock(&cgroup_mutex);
+
+	for (type = 0; type < ARRAY_SIZE(cgrp->bpf.progs); type++) {
+		struct list_head *progs = &cgrp->bpf.progs[type];
+		struct bpf_prog_list *pl, *pltmp;
+
+		list_for_each_entry_safe(pl, pltmp, progs, node) {
+			list_del(&pl->node);
+			if (pl->prog)
+				bpf_prog_put(pl->prog);
+			if (pl->link)
+				bpf_cgroup_link_auto_detach(pl->link);
+			kfree(pl);
+			static_branch_dec(&cgroup_bpf_enabled_key);
+		}
+		old_array = rcu_dereference_protected(
+				cgrp->bpf.effective[type],
+				lockdep_is_held(&cgroup_mutex));
+		bpf_prog_array_free(old_array);
+	}
+
+	list_for_each_entry_safe(storage, stmp, storages, list_cg) {
+		bpf_cgroup_storage_unlink(storage);
+		bpf_cgroup_storage_free(storage);
+	}
+
+	mutex_unlock(&cgroup_mutex);
+
+	for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
+		cgroup_bpf_put(p);
+
+	percpu_ref_exit(&cgrp->bpf.refcnt);
+	cgroup_put(cgrp);
+}
+
+/**
+ * cgroup_bpf_release_fn() - callback used to schedule releasing
+ *                           of bpf cgroup data
+ * @ref: percpu ref counter structure
+ */
+static void cgroup_bpf_release_fn(struct percpu_ref *ref)
+{
+	struct cgroup *cgrp = container_of(ref, struct cgroup, bpf.refcnt);
+
+	INIT_WORK(&cgrp->bpf.release_work, cgroup_bpf_release);
+	queue_work(system_wq, &cgrp->bpf.release_work);
+}
+
+/* Get underlying bpf_prog of bpf_prog_list entry, regardless if it's through
+ * link or direct prog.
+ */
+static struct bpf_prog *prog_list_prog(struct bpf_prog_list *pl)
+{
+	if (pl->prog)
+		return pl->prog;
+	if (pl->link)
+		return pl->link->link.prog;
+	return NULL;
+}
+
+/* count number of elements in the list.
+ * it's slow but the list cannot be long
+ */
+static u32 prog_list_length(struct list_head *head)
+{
+	struct bpf_prog_list *pl;
+	u32 cnt = 0;
+
+	list_for_each_entry(pl, head, node) {
+		if (!prog_list_prog(pl))
+			continue;
+		cnt++;
+	}
+	return cnt;
+}
+
+/* if parent has non-overridable prog attached,
+ * disallow attaching new programs to the descendent cgroup.
+ * if parent has overridable or multi-prog, allow attaching
+ */
+static bool hierarchy_allows_attach(struct cgroup *cgrp,
+				    enum bpf_attach_type type)
+{
+	struct cgroup *p;
+
+	p = cgroup_parent(cgrp);
+	if (!p)
+		return true;
+	do {
+		u32 flags = p->bpf.flags[type];
+		u32 cnt;
+
+		if (flags & BPF_F_ALLOW_MULTI)
+			return true;
+		cnt = prog_list_length(&p->bpf.progs[type]);
+		WARN_ON_ONCE(cnt > 1);
+		if (cnt == 1)
+			return !!(flags & BPF_F_ALLOW_OVERRIDE);
+		p = cgroup_parent(p);
+	} while (p);
+	return true;
+}
+
+/* compute a chain of effective programs for a given cgroup:
+ * start from the list of programs in this cgroup and add
+ * all parent programs.
+ * Note that parent's F_ALLOW_OVERRIDE-type program is yielding
+ * to programs in this cgroup
+ */
+static int compute_effective_progs(struct cgroup *cgrp,
+				   enum bpf_attach_type type,
+				   struct bpf_prog_array **array)
+{
+	struct bpf_prog_array_item *item;
+	struct bpf_prog_array *progs;
+	struct bpf_prog_list *pl;
+	struct cgroup *p = cgrp;
+	int cnt = 0;
+
+	/* count number of effective programs by walking parents */
+	do {
+		if (cnt == 0 || (p->bpf.flags[type] & BPF_F_ALLOW_MULTI))
+			cnt += prog_list_length(&p->bpf.progs[type]);
+		p = cgroup_parent(p);
+	} while (p);
+
+	progs = bpf_prog_array_alloc(cnt, GFP_KERNEL);
+	if (!progs)
+		return -ENOMEM;
+
+	/* populate the array with effective progs */
+	cnt = 0;
+	p = cgrp;
+	do {
+		if (cnt > 0 && !(p->bpf.flags[type] & BPF_F_ALLOW_MULTI))
+			continue;
+
+		list_for_each_entry(pl, &p->bpf.progs[type], node) {
+			if (!prog_list_prog(pl))
+				continue;
+
+			item = &progs->items[cnt];
+			item->prog = prog_list_prog(pl);
+			bpf_cgroup_storages_assign(item->cgroup_storage,
+						   pl->storage);
+			cnt++;
+		}
+	} while ((p = cgroup_parent(p)));
+
+	*array = progs;
+	return 0;
+}
+
+static void activate_effective_progs(struct cgroup *cgrp,
+				     enum bpf_attach_type type,
+				     struct bpf_prog_array *old_array)
+{
+	old_array = rcu_replace_pointer(cgrp->bpf.effective[type], old_array,
+					lockdep_is_held(&cgroup_mutex));
+	/* free prog array after grace period, since __cgroup_bpf_run_*()
+	 * might be still walking the array
+	 */
+	bpf_prog_array_free(old_array);
+}
+
+/**
+ * cgroup_bpf_inherit() - inherit effective programs from parent
+ * @cgrp: the cgroup to modify
+ */
+int cgroup_bpf_inherit(struct cgroup *cgrp)
+{
+/* has to use marco instead of const int, since compiler thinks
+ * that array below is variable length
+ */
+#define	NR ARRAY_SIZE(cgrp->bpf.effective)
+	struct bpf_prog_array *arrays[NR] = {};
+	struct cgroup *p;
+	int ret, i;
+
+	ret = percpu_ref_init(&cgrp->bpf.refcnt, cgroup_bpf_release_fn, 0,
+			      GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
+		cgroup_bpf_get(p);
+
+	for (i = 0; i < NR; i++)
+		INIT_LIST_HEAD(&cgrp->bpf.progs[i]);
+
+	INIT_LIST_HEAD(&cgrp->bpf.storages);
+
+	for (i = 0; i < NR; i++)
+		if (compute_effective_progs(cgrp, i, &arrays[i]))
+			goto cleanup;
+
+	for (i = 0; i < NR; i++)
+		activate_effective_progs(cgrp, i, arrays[i]);
+
+	return 0;
+cleanup:
+	for (i = 0; i < NR; i++)
+		bpf_prog_array_free(arrays[i]);
+
+	for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
+		cgroup_bpf_put(p);
+
+	percpu_ref_exit(&cgrp->bpf.refcnt);
+
+	return -ENOMEM;
+}
+
+static int update_effective_progs(struct cgroup *cgrp,
+				  enum bpf_attach_type type)
+{
+	struct cgroup_subsys_state *css;
+	int err;
+
+	/* allocate and recompute effective prog arrays */
+	css_for_each_descendant_pre(css, &cgrp->self) {
+		struct cgroup *desc = container_of(css, struct cgroup, self);
+
+		if (percpu_ref_is_zero(&desc->bpf.refcnt))
+			continue;
+
+		err = compute_effective_progs(desc, type, &desc->bpf.inactive);
+		if (err)
+			goto cleanup;
+	}
+
+	/* all allocations were successful. Activate all prog arrays */
+	css_for_each_descendant_pre(css, &cgrp->self) {
+		struct cgroup *desc = container_of(css, struct cgroup, self);
+
+		if (percpu_ref_is_zero(&desc->bpf.refcnt)) {
+			if (unlikely(desc->bpf.inactive)) {
+				bpf_prog_array_free(desc->bpf.inactive);
+				desc->bpf.inactive = NULL;
+			}
+			continue;
+		}
+
+		activate_effective_progs(desc, type, desc->bpf.inactive);
+		desc->bpf.inactive = NULL;
+	}
+
+	return 0;
+
+cleanup:
+	/* oom while computing effective. Free all computed effective arrays
+	 * since they were not activated
+	 */
+	css_for_each_descendant_pre(css, &cgrp->self) {
+		struct cgroup *desc = container_of(css, struct cgroup, self);
+
+		bpf_prog_array_free(desc->bpf.inactive);
+		desc->bpf.inactive = NULL;
+	}
+
+	return err;
+}
+
+#define BPF_CGROUP_MAX_PROGS 64
+
+static struct bpf_prog_list *find_attach_entry(struct list_head *progs,
+					       struct bpf_prog *prog,
+					       struct bpf_cgroup_link *link,
+					       struct bpf_prog *replace_prog,
+					       bool allow_multi)
+{
+	struct bpf_prog_list *pl;
+
+	/* single-attach case */
+	if (!allow_multi) {
+		if (list_empty(progs))
+			return NULL;
+		return list_first_entry(progs, typeof(*pl), node);
+	}
+
+	list_for_each_entry(pl, progs, node) {
+		if (prog && pl->prog == prog && prog != replace_prog)
+			/* disallow attaching the same prog twice */
+			return ERR_PTR(-EINVAL);
+		if (link && pl->link == link)
+			/* disallow attaching the same link twice */
+			return ERR_PTR(-EINVAL);
+	}
+
+	/* direct prog multi-attach w/ replacement case */
+	if (replace_prog) {
+		list_for_each_entry(pl, progs, node) {
+			if (pl->prog == replace_prog)
+				/* a match found */
+				return pl;
+		}
+		/* prog to replace not found for cgroup */
+		return ERR_PTR(-ENOENT);
+	}
+
+	return NULL;
+}
+
+/**
+ * __cgroup_bpf_attach() - Attach the program or the link to a cgroup, and
+ *                         propagate the change to descendants
+ * @cgrp: The cgroup which descendants to traverse
+ * @prog: A program to attach
+ * @link: A link to attach
+ * @replace_prog: Previously attached program to replace if BPF_F_REPLACE is set
+ * @type: Type of attach operation
+ * @flags: Option flags
+ *
+ * Exactly one of @prog or @link can be non-null.
+ * Must be called with cgroup_mutex held.
+ */
+int __cgroup_bpf_attach(struct cgroup *cgrp,
+			struct bpf_prog *prog, struct bpf_prog *replace_prog,
+			struct bpf_cgroup_link *link,
+			enum bpf_attach_type type, u32 flags)
+{
+	u32 saved_flags = (flags & (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI));
+	struct list_head *progs = &cgrp->bpf.progs[type];
+	struct bpf_prog *old_prog = NULL;
+	struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
+	struct bpf_cgroup_storage *new_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
+	struct bpf_prog_list *pl;
+	int err;
+
+	if (((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI)) ||
+	    ((flags & BPF_F_REPLACE) && !(flags & BPF_F_ALLOW_MULTI)))
+		/* invalid combination */
+		return -EINVAL;
+	if (link && (prog || replace_prog))
+		/* only either link or prog/replace_prog can be specified */
+		return -EINVAL;
+	if (!!replace_prog != !!(flags & BPF_F_REPLACE))
+		/* replace_prog implies BPF_F_REPLACE, and vice versa */
+		return -EINVAL;
+
+	if (!hierarchy_allows_attach(cgrp, type))
+		return -EPERM;
+
+	if (!list_empty(progs) && cgrp->bpf.flags[type] != saved_flags)
+		/* Disallow attaching non-overridable on top
+		 * of existing overridable in this cgroup.
+		 * Disallow attaching multi-prog if overridable or none
+		 */
+		return -EPERM;
+
+	if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS)
+		return -E2BIG;
+
+	pl = find_attach_entry(progs, prog, link, replace_prog,
+			       flags & BPF_F_ALLOW_MULTI);
+	if (IS_ERR(pl))
+		return PTR_ERR(pl);
+
+	if (bpf_cgroup_storages_alloc(storage, new_storage, type,
+				      prog ? : link->link.prog, cgrp))
+		return -ENOMEM;
+
+	if (pl) {
+		old_prog = pl->prog;
+	} else {
+		pl = kmalloc(sizeof(*pl), GFP_KERNEL);
+		if (!pl) {
+			bpf_cgroup_storages_free(new_storage);
+			return -ENOMEM;
+		}
+		list_add_tail(&pl->node, progs);
+	}
+
+	pl->prog = prog;
+	pl->link = link;
+	bpf_cgroup_storages_assign(pl->storage, storage);
+	cgrp->bpf.flags[type] = saved_flags;
+
+	err = update_effective_progs(cgrp, type);
+	if (err)
+		goto cleanup;
+
+	if (old_prog)
+		bpf_prog_put(old_prog);
+	else
+		static_branch_inc(&cgroup_bpf_enabled_key);
+	bpf_cgroup_storages_link(new_storage, cgrp, type);
+	return 0;
+
+cleanup:
+	if (old_prog) {
+		pl->prog = old_prog;
+		pl->link = NULL;
+	}
+	bpf_cgroup_storages_free(new_storage);
+	if (!old_prog) {
+		list_del(&pl->node);
+		kfree(pl);
+	}
+	return err;
+}
+
+/* Swap updated BPF program for given link in effective program arrays across
+ * all descendant cgroups. This function is guaranteed to succeed.
+ */
+static void replace_effective_prog(struct cgroup *cgrp,
+				   enum bpf_attach_type type,
+				   struct bpf_cgroup_link *link)
+{
+	struct bpf_prog_array_item *item;
+	struct cgroup_subsys_state *css;
+	struct bpf_prog_array *progs;
+	struct bpf_prog_list *pl;
+	struct list_head *head;
+	struct cgroup *cg;
+	int pos;
+
+	css_for_each_descendant_pre(css, &cgrp->self) {
+		struct cgroup *desc = container_of(css, struct cgroup, self);
+
+		if (percpu_ref_is_zero(&desc->bpf.refcnt))
+			continue;
+
+		/* find position of link in effective progs array */
+		for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) {
+			if (pos && !(cg->bpf.flags[type] & BPF_F_ALLOW_MULTI))
+				continue;
+
+			head = &cg->bpf.progs[type];
+			list_for_each_entry(pl, head, node) {
+				if (!prog_list_prog(pl))
+					continue;
+				if (pl->link == link)
+					goto found;
+				pos++;
+			}
+		}
+found:
+		BUG_ON(!cg);
+		progs = rcu_dereference_protected(
+				desc->bpf.effective[type],
+				lockdep_is_held(&cgroup_mutex));
+		item = &progs->items[pos];
+		WRITE_ONCE(item->prog, link->link.prog);
+	}
+}
+
+/**
+ * __cgroup_bpf_replace() - Replace link's program and propagate the change
+ *                          to descendants
+ * @cgrp: The cgroup which descendants to traverse
+ * @link: A link for which to replace BPF program
+ * @type: Type of attach operation
+ *
+ * Must be called with cgroup_mutex held.
+ */
+static int __cgroup_bpf_replace(struct cgroup *cgrp,
+				struct bpf_cgroup_link *link,
+				struct bpf_prog *new_prog)
+{
+	struct list_head *progs = &cgrp->bpf.progs[link->type];
+	struct bpf_prog *old_prog;
+	struct bpf_prog_list *pl;
+	bool found = false;
+
+	if (link->link.prog->type != new_prog->type)
+		return -EINVAL;
+
+	list_for_each_entry(pl, progs, node) {
+		if (pl->link == link) {
+			found = true;
+			break;
+		}
+	}
+	if (!found)
+		return -ENOENT;
+
+	old_prog = xchg(&link->link.prog, new_prog);
+	replace_effective_prog(cgrp, link->type, link);
+	bpf_prog_put(old_prog);
+	return 0;
+}
+
+static int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *new_prog,
+			      struct bpf_prog *old_prog)
+{
+	struct bpf_cgroup_link *cg_link;
+	int ret;
+
+	cg_link = container_of(link, struct bpf_cgroup_link, link);
+
+	mutex_lock(&cgroup_mutex);
+	/* link might have been auto-released by dying cgroup, so fail */
+	if (!cg_link->cgroup) {
+		ret = -ENOLINK;
+		goto out_unlock;
+	}
+	if (old_prog && link->prog != old_prog) {
+		ret = -EPERM;
+		goto out_unlock;
+	}
+	ret = __cgroup_bpf_replace(cg_link->cgroup, cg_link, new_prog);
+out_unlock:
+	mutex_unlock(&cgroup_mutex);
+	return ret;
+}
+
+static struct bpf_prog_list *find_detach_entry(struct list_head *progs,
+					       struct bpf_prog *prog,
+					       struct bpf_cgroup_link *link,
+					       bool allow_multi)
+{
+	struct bpf_prog_list *pl;
+
+	if (!allow_multi) {
+		if (list_empty(progs))
+			/* report error when trying to detach and nothing is attached */
+			return ERR_PTR(-ENOENT);
+
+		/* to maintain backward compatibility NONE and OVERRIDE cgroups
+		 * allow detaching with invalid FD (prog==NULL) in legacy mode
+		 */
+		return list_first_entry(progs, typeof(*pl), node);
+	}
+
+	if (!prog && !link)
+		/* to detach MULTI prog the user has to specify valid FD
+		 * of the program or link to be detached
+		 */
+		return ERR_PTR(-EINVAL);
+
+	/* find the prog or link and detach it */
+	list_for_each_entry(pl, progs, node) {
+		if (pl->prog == prog && pl->link == link)
+			return pl;
+	}
+	return ERR_PTR(-ENOENT);
+}
+
+/**
+ * purge_effective_progs() - After compute_effective_progs fails to alloc new
+ *			     cgrp->bpf.inactive table we can recover by
+ *			     recomputing the array in place.
+ *
+ * @cgrp: The cgroup which descendants to travers
+ * @prog: A program to detach or NULL
+ * @link: A link to detach or NULL
+ * @type: Type of detach operation
+ */
+static void purge_effective_progs(struct cgroup *cgrp, struct bpf_prog *prog,
+				  struct bpf_cgroup_link *link,
+				  enum bpf_attach_type type)
+{
+	struct cgroup_subsys_state *css;
+	struct bpf_prog_array *progs;
+	struct bpf_prog_list *pl;
+	struct list_head *head;
+	struct cgroup *cg;
+	int pos;
+
+	/* recompute effective prog array in place */
+	css_for_each_descendant_pre(css, &cgrp->self) {
+		struct cgroup *desc = container_of(css, struct cgroup, self);
+
+		if (percpu_ref_is_zero(&desc->bpf.refcnt))
+			continue;
+
+		/* find position of link or prog in effective progs array */
+		for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) {
+			if (pos && !(cg->bpf.flags[type] & BPF_F_ALLOW_MULTI))
+				continue;
+
+			head = &cg->bpf.progs[type];
+			list_for_each_entry(pl, head, node) {
+				if (!prog_list_prog(pl))
+					continue;
+				if (pl->prog == prog && pl->link == link)
+					goto found;
+				pos++;
+			}
+		}
+
+		/* no link or prog match, skip the cgroup of this layer */
+		continue;
+found:
+		progs = rcu_dereference_protected(
+				desc->bpf.effective[type],
+				lockdep_is_held(&cgroup_mutex));
+
+		/* Remove the program from the array */
+		WARN_ONCE(bpf_prog_array_delete_safe_at(progs, pos),
+			  "Failed to purge a prog from array at index %d", pos);
+	}
+}
+
+/**
+ * __cgroup_bpf_detach() - Detach the program or link from a cgroup, and
+ *                         propagate the change to descendants
+ * @cgrp: The cgroup which descendants to traverse
+ * @prog: A program to detach or NULL
+ * @prog: A link to detach or NULL
+ * @type: Type of detach operation
+ *
+ * At most one of @prog or @link can be non-NULL.
+ * Must be called with cgroup_mutex held.
+ */
+int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
+			struct bpf_cgroup_link *link, enum bpf_attach_type type)
+{
+	struct list_head *progs = &cgrp->bpf.progs[type];
+	u32 flags = cgrp->bpf.flags[type];
+	struct bpf_prog_list *pl;
+	struct bpf_prog *old_prog;
+
+	if (prog && link)
+		/* only one of prog or link can be specified */
+		return -EINVAL;
+
+	pl = find_detach_entry(progs, prog, link, flags & BPF_F_ALLOW_MULTI);
+	if (IS_ERR(pl))
+		return PTR_ERR(pl);
+
+	/* mark it deleted, so it's ignored while recomputing effective */
+	old_prog = pl->prog;
+	pl->prog = NULL;
+	pl->link = NULL;
+
+	if (update_effective_progs(cgrp, type)) {
+		/* if update effective array failed replace the prog with a dummy prog*/
+		pl->prog = old_prog;
+		pl->link = link;
+		purge_effective_progs(cgrp, old_prog, link, type);
+	}
+
+	/* now can actually delete it from this cgroup list */
+	list_del(&pl->node);
+	kfree(pl);
+	if (list_empty(progs))
+		/* last program was detached, reset flags to zero */
+		cgrp->bpf.flags[type] = 0;
+	if (old_prog)
+		bpf_prog_put(old_prog);
+	static_branch_dec(&cgroup_bpf_enabled_key);
+	return 0;
+}
+
+/* Must be called with cgroup_mutex held to avoid races. */
+int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
+		       union bpf_attr __user *uattr)
+{
+	__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
+	enum bpf_attach_type type = attr->query.attach_type;
+	struct list_head *progs = &cgrp->bpf.progs[type];
+	u32 flags = cgrp->bpf.flags[type];
+	struct bpf_prog_array *effective;
+	struct bpf_prog *prog;
+	int cnt, ret = 0, i;
+
+	effective = rcu_dereference_protected(cgrp->bpf.effective[type],
+					      lockdep_is_held(&cgroup_mutex));
+
+	if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE)
+		cnt = bpf_prog_array_length(effective);
+	else
+		cnt = prog_list_length(progs);
+
+	if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
+		return -EFAULT;
+	if (copy_to_user(&uattr->query.prog_cnt, &cnt, sizeof(cnt)))
+		return -EFAULT;
+	if (attr->query.prog_cnt == 0 || !prog_ids || !cnt)
+		/* return early if user requested only program count + flags */
+		return 0;
+	if (attr->query.prog_cnt < cnt) {
+		cnt = attr->query.prog_cnt;
+		ret = -ENOSPC;
+	}
+
+	if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) {
+		return bpf_prog_array_copy_to_user(effective, prog_ids, cnt);
+	} else {
+		struct bpf_prog_list *pl;
+		u32 id;
+
+		i = 0;
+		list_for_each_entry(pl, progs, node) {
+			prog = prog_list_prog(pl);
+			id = prog->aux->id;
+			if (copy_to_user(prog_ids + i, &id, sizeof(id)))
+				return -EFAULT;
+			if (++i == cnt)
+				break;
+		}
+	}
+	return ret;
+}
+
+int cgroup_bpf_prog_attach(const union bpf_attr *attr,
+			   enum bpf_prog_type ptype, struct bpf_prog *prog)
+{
+	struct bpf_prog *replace_prog = NULL;
+	struct cgroup *cgrp;
+	int ret;
+
+	cgrp = cgroup_get_from_fd(attr->target_fd);
+	if (IS_ERR(cgrp))
+		return PTR_ERR(cgrp);
+
+	if ((attr->attach_flags & BPF_F_ALLOW_MULTI) &&
+	    (attr->attach_flags & BPF_F_REPLACE)) {
+		replace_prog = bpf_prog_get_type(attr->replace_bpf_fd, ptype);
+		if (IS_ERR(replace_prog)) {
+			cgroup_put(cgrp);
+			return PTR_ERR(replace_prog);
+		}
+	}
+
+	ret = cgroup_bpf_attach(cgrp, prog, replace_prog, NULL,
+				attr->attach_type, attr->attach_flags);
+
+	if (replace_prog)
+		bpf_prog_put(replace_prog);
+	cgroup_put(cgrp);
+	return ret;
+}
+
+int cgroup_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
+{
+	struct bpf_prog *prog;
+	struct cgroup *cgrp;
+	int ret;
+
+	cgrp = cgroup_get_from_fd(attr->target_fd);
+	if (IS_ERR(cgrp))
+		return PTR_ERR(cgrp);
+
+	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
+	if (IS_ERR(prog))
+		prog = NULL;
+
+	ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type);
+	if (prog)
+		bpf_prog_put(prog);
+
+	cgroup_put(cgrp);
+	return ret;
+}
+
+static void bpf_cgroup_link_release(struct bpf_link *link)
+{
+	struct bpf_cgroup_link *cg_link =
+		container_of(link, struct bpf_cgroup_link, link);
+	struct cgroup *cg;
+
+	/* link might have been auto-detached by dying cgroup already,
+	 * in that case our work is done here
+	 */
+	if (!cg_link->cgroup)
+		return;
+
+	mutex_lock(&cgroup_mutex);
+
+	/* re-check cgroup under lock again */
+	if (!cg_link->cgroup) {
+		mutex_unlock(&cgroup_mutex);
+		return;
+	}
+
+	WARN_ON(__cgroup_bpf_detach(cg_link->cgroup, NULL, cg_link,
+				    cg_link->type));
+
+	cg = cg_link->cgroup;
+	cg_link->cgroup = NULL;
+
+	mutex_unlock(&cgroup_mutex);
+
+	cgroup_put(cg);
+}
+
+static void bpf_cgroup_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_cgroup_link *cg_link =
+		container_of(link, struct bpf_cgroup_link, link);
+
+	kfree(cg_link);
+}
+
+static int bpf_cgroup_link_detach(struct bpf_link *link)
+{
+	bpf_cgroup_link_release(link);
+
+	return 0;
+}
+
+static void bpf_cgroup_link_show_fdinfo(const struct bpf_link *link,
+					struct seq_file *seq)
+{
+	struct bpf_cgroup_link *cg_link =
+		container_of(link, struct bpf_cgroup_link, link);
+	u64 cg_id = 0;
+
+	mutex_lock(&cgroup_mutex);
+	if (cg_link->cgroup)
+		cg_id = cgroup_id(cg_link->cgroup);
+	mutex_unlock(&cgroup_mutex);
+
+	seq_printf(seq,
+		   "cgroup_id:\t%llu\n"
+		   "attach_type:\t%d\n",
+		   cg_id,
+		   cg_link->type);
+}
+
+static int bpf_cgroup_link_fill_link_info(const struct bpf_link *link,
+					  struct bpf_link_info *info)
+{
+	struct bpf_cgroup_link *cg_link =
+		container_of(link, struct bpf_cgroup_link, link);
+	u64 cg_id = 0;
+
+	mutex_lock(&cgroup_mutex);
+	if (cg_link->cgroup)
+		cg_id = cgroup_id(cg_link->cgroup);
+	mutex_unlock(&cgroup_mutex);
+
+	info->cgroup.cgroup_id = cg_id;
+	info->cgroup.attach_type = cg_link->type;
+	return 0;
+}
+
+static const struct bpf_link_ops bpf_cgroup_link_lops = {
+	.release = bpf_cgroup_link_release,
+	.dealloc = bpf_cgroup_link_dealloc,
+	.detach = bpf_cgroup_link_detach,
+	.update_prog = cgroup_bpf_replace,
+	.show_fdinfo = bpf_cgroup_link_show_fdinfo,
+	.fill_link_info = bpf_cgroup_link_fill_link_info,
+};
+
+int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	struct bpf_link_primer link_primer;
+	struct bpf_cgroup_link *link;
+	struct cgroup *cgrp;
+	int err;
+
+	if (attr->link_create.flags)
+		return -EINVAL;
+
+	cgrp = cgroup_get_from_fd(attr->link_create.target_fd);
+	if (IS_ERR(cgrp))
+		return PTR_ERR(cgrp);
+
+	link = kzalloc(sizeof(*link), GFP_USER);
+	if (!link) {
+		err = -ENOMEM;
+		goto out_put_cgroup;
+	}
+	bpf_link_init(&link->link, BPF_LINK_TYPE_CGROUP, &bpf_cgroup_link_lops,
+		      prog);
+	link->cgroup = cgrp;
+	link->type = attr->link_create.attach_type;
+
+	err  = bpf_link_prime(&link->link, &link_primer);
+	if (err) {
+		kfree(link);
+		goto out_put_cgroup;
+	}
+
+	err = cgroup_bpf_attach(cgrp, NULL, NULL, link, link->type,
+				BPF_F_ALLOW_MULTI);
+	if (err) {
+		bpf_link_cleanup(&link_primer);
+		goto out_put_cgroup;
+	}
+
+	return bpf_link_settle(&link_primer);
+
+out_put_cgroup:
+	cgroup_put(cgrp);
+	return err;
+}
+
+int cgroup_bpf_prog_query(const union bpf_attr *attr,
+			  union bpf_attr __user *uattr)
+{
+	struct cgroup *cgrp;
+	int ret;
+
+	cgrp = cgroup_get_from_fd(attr->query.target_fd);
+	if (IS_ERR(cgrp))
+		return PTR_ERR(cgrp);
+
+	ret = cgroup_bpf_query(cgrp, attr, uattr);
+
+	cgroup_put(cgrp);
+	return ret;
+}
+
+/**
+ * __cgroup_bpf_run_filter_skb() - Run a program for packet filtering
+ * @sk: The socket sending or receiving traffic
+ * @skb: The skb that is being sent or received
+ * @type: The type of program to be exectuted
+ *
+ * If no socket is passed, or the socket is not of type INET or INET6,
+ * this function does nothing and returns 0.
+ *
+ * The program type passed in via @type must be suitable for network
+ * filtering. No further check is performed to assert that.
+ *
+ * For egress packets, this function can return:
+ *   NET_XMIT_SUCCESS    (0)	- continue with packet output
+ *   NET_XMIT_DROP       (1)	- drop packet and notify TCP to call cwr
+ *   NET_XMIT_CN         (2)	- continue with packet output and notify TCP
+ *				  to call cwr
+ *   -EPERM			- drop packet
+ *
+ * For ingress packets, this function will return -EPERM if any
+ * attached program was found and if it returned != 1 during execution.
+ * Otherwise 0 is returned.
+ */
+int __cgroup_bpf_run_filter_skb(struct sock *sk,
+				struct sk_buff *skb,
+				enum bpf_attach_type type)
+{
+	unsigned int offset = skb->data - skb_network_header(skb);
+	struct sock *save_sk;
+	void *saved_data_end;
+	struct cgroup *cgrp;
+	int ret;
+
+	if (!sk || !sk_fullsock(sk))
+		return 0;
+
+	if (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)
+		return 0;
+
+	cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+	save_sk = skb->sk;
+	skb->sk = sk;
+	__skb_push(skb, offset);
+
+	/* compute pointers for the bpf prog */
+	bpf_compute_and_save_data_end(skb, &saved_data_end);
+
+	if (type == BPF_CGROUP_INET_EGRESS) {
+		ret = BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY(
+			cgrp->bpf.effective[type], skb, __bpf_prog_run_save_cb);
+	} else {
+		ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb,
+					  __bpf_prog_run_save_cb);
+		ret = (ret == 1 ? 0 : -EPERM);
+	}
+	bpf_restore_data_end(skb, saved_data_end);
+	__skb_pull(skb, offset);
+	skb->sk = save_sk;
+
+	return ret;
+}
+EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb);
+
+/**
+ * __cgroup_bpf_run_filter_sk() - Run a program on a sock
+ * @sk: sock structure to manipulate
+ * @type: The type of program to be exectuted
+ *
+ * socket is passed is expected to be of type INET or INET6.
+ *
+ * The program type passed in via @type must be suitable for sock
+ * filtering. No further check is performed to assert that.
+ *
+ * This function will return %-EPERM if any if an attached program was found
+ * and if it returned != 1 during execution. In all other cases, 0 is returned.
+ */
+int __cgroup_bpf_run_filter_sk(struct sock *sk,
+			       enum bpf_attach_type type)
+{
+	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+	int ret;
+
+	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sk, BPF_PROG_RUN);
+	return ret == 1 ? 0 : -EPERM;
+}
+EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk);
+
+/**
+ * __cgroup_bpf_run_filter_sock_addr() - Run a program on a sock and
+ *                                       provided by user sockaddr
+ * @sk: sock struct that will use sockaddr
+ * @uaddr: sockaddr struct provided by user
+ * @type: The type of program to be exectuted
+ * @t_ctx: Pointer to attach type specific context
+ *
+ * socket is expected to be of type INET or INET6.
+ *
+ * This function will return %-EPERM if an attached program is found and
+ * returned value != 1 during execution. In all other cases, 0 is returned.
+ */
+int __cgroup_bpf_run_filter_sock_addr(struct sock *sk,
+				      struct sockaddr *uaddr,
+				      enum bpf_attach_type type,
+				      void *t_ctx)
+{
+	struct bpf_sock_addr_kern ctx = {
+		.sk = sk,
+		.uaddr = uaddr,
+		.t_ctx = t_ctx,
+	};
+	struct sockaddr_storage unspec;
+	struct cgroup *cgrp;
+	int ret;
+
+	/* Check socket family since not all sockets represent network
+	 * endpoint (e.g. AF_UNIX).
+	 */
+	if (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)
+		return 0;
+
+	if (!ctx.uaddr) {
+		memset(&unspec, 0, sizeof(unspec));
+		ctx.uaddr = (struct sockaddr *)&unspec;
+	}
+
+	cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN);
+
+	return ret == 1 ? 0 : -EPERM;
+}
+EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr);
+
+/**
+ * __cgroup_bpf_run_filter_sock_ops() - Run a program on a sock
+ * @sk: socket to get cgroup from
+ * @sock_ops: bpf_sock_ops_kern struct to pass to program. Contains
+ * sk with connection information (IP addresses, etc.) May not contain
+ * cgroup info if it is a req sock.
+ * @type: The type of program to be exectuted
+ *
+ * socket passed is expected to be of type INET or INET6.
+ *
+ * The program type passed in via @type must be suitable for sock_ops
+ * filtering. No further check is performed to assert that.
+ *
+ * This function will return %-EPERM if any if an attached program was found
+ * and if it returned != 1 during execution. In all other cases, 0 is returned.
+ */
+int __cgroup_bpf_run_filter_sock_ops(struct sock *sk,
+				     struct bpf_sock_ops_kern *sock_ops,
+				     enum bpf_attach_type type)
+{
+	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+	int ret;
+
+	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sock_ops,
+				 BPF_PROG_RUN);
+	return ret == 1 ? 0 : -EPERM;
+}
+EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops);
+
+int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
+				      short access, enum bpf_attach_type type)
+{
+	struct cgroup *cgrp;
+	struct bpf_cgroup_dev_ctx ctx = {
+		.access_type = (access << 16) | dev_type,
+		.major = major,
+		.minor = minor,
+	};
+	int allow = 1;
+
+	rcu_read_lock();
+	cgrp = task_dfl_cgroup(current);
+	allow = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx,
+				   BPF_PROG_RUN);
+	rcu_read_unlock();
+
+	return !allow;
+}
+
+static const struct bpf_func_proto *
+cgroup_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	switch (func_id) {
+	case BPF_FUNC_get_current_uid_gid:
+		return &bpf_get_current_uid_gid_proto;
+	case BPF_FUNC_get_local_storage:
+		return &bpf_get_local_storage_proto;
+	case BPF_FUNC_get_current_cgroup_id:
+		return &bpf_get_current_cgroup_id_proto;
+	case BPF_FUNC_perf_event_output:
+		return &bpf_event_output_data_proto;
+	default:
+		return bpf_base_func_proto(func_id);
+	}
+}
+
+static const struct bpf_func_proto *
+cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	return cgroup_base_func_proto(func_id, prog);
+}
+
+static bool cgroup_dev_is_valid_access(int off, int size,
+				       enum bpf_access_type type,
+				       const struct bpf_prog *prog,
+				       struct bpf_insn_access_aux *info)
+{
+	const int size_default = sizeof(__u32);
+
+	if (type == BPF_WRITE)
+		return false;
+
+	if (off < 0 || off + size > sizeof(struct bpf_cgroup_dev_ctx))
+		return false;
+	/* The verifier guarantees that size > 0. */
+	if (off % size != 0)
+		return false;
+
+	switch (off) {
+	case bpf_ctx_range(struct bpf_cgroup_dev_ctx, access_type):
+		bpf_ctx_record_field_size(info, size_default);
+		if (!bpf_ctx_narrow_access_ok(off, size, size_default))
+			return false;
+		break;
+	default:
+		if (size != size_default)
+			return false;
+	}
+
+	return true;
+}
+
+const struct bpf_prog_ops cg_dev_prog_ops = {
+};
+
+const struct bpf_verifier_ops cg_dev_verifier_ops = {
+	.get_func_proto		= cgroup_dev_func_proto,
+	.is_valid_access	= cgroup_dev_is_valid_access,
+};
+
+/**
+ * __cgroup_bpf_run_filter_sysctl - Run a program on sysctl
+ *
+ * @head: sysctl table header
+ * @table: sysctl table
+ * @write: sysctl is being read (= 0) or written (= 1)
+ * @buf: pointer to buffer (in and out)
+ * @pcount: value-result argument: value is size of buffer pointed to by @buf,
+ *	result is size of @new_buf if program set new value, initial value
+ *	otherwise
+ * @ppos: value-result argument: value is position at which read from or write
+ *	to sysctl is happening, result is new position if program overrode it,
+ *	initial value otherwise
+ * @type: type of program to be executed
+ *
+ * Program is run when sysctl is being accessed, either read or written, and
+ * can allow or deny such access.
+ *
+ * This function will return %-EPERM if an attached program is found and
+ * returned value != 1 during execution. In all other cases 0 is returned.
+ */
+int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
+				   struct ctl_table *table, int write,
+				   char **buf, size_t *pcount, loff_t *ppos,
+				   enum bpf_attach_type type)
+{
+	struct bpf_sysctl_kern ctx = {
+		.head = head,
+		.table = table,
+		.write = write,
+		.ppos = ppos,
+		.cur_val = NULL,
+		.cur_len = PAGE_SIZE,
+		.new_val = NULL,
+		.new_len = 0,
+		.new_updated = 0,
+	};
+	struct cgroup *cgrp;
+	loff_t pos = 0;
+	int ret;
+
+	ctx.cur_val = kmalloc_track_caller(ctx.cur_len, GFP_KERNEL);
+	if (!ctx.cur_val ||
+	    table->proc_handler(table, 0, ctx.cur_val, &ctx.cur_len, &pos)) {
+		/* Let BPF program decide how to proceed. */
+		ctx.cur_len = 0;
+	}
+
+	if (write && *buf && *pcount) {
+		/* BPF program should be able to override new value with a
+		 * buffer bigger than provided by user.
+		 */
+		ctx.new_val = kmalloc_track_caller(PAGE_SIZE, GFP_KERNEL);
+		ctx.new_len = min_t(size_t, PAGE_SIZE, *pcount);
+		if (ctx.new_val) {
+			memcpy(ctx.new_val, *buf, ctx.new_len);
+		} else {
+			/* Let BPF program decide how to proceed. */
+			ctx.new_len = 0;
+		}
+	}
+
+	rcu_read_lock();
+	cgrp = task_dfl_cgroup(current);
+	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN);
+	rcu_read_unlock();
+
+	kfree(ctx.cur_val);
+
+	if (ret == 1 && ctx.new_updated) {
+		kfree(*buf);
+		*buf = ctx.new_val;
+		*pcount = ctx.new_len;
+	} else {
+		kfree(ctx.new_val);
+	}
+
+	return ret == 1 ? 0 : -EPERM;
+}
+
+#ifdef CONFIG_NET
+static bool __cgroup_bpf_prog_array_is_empty(struct cgroup *cgrp,
+					     enum bpf_attach_type attach_type)
+{
+	struct bpf_prog_array *prog_array;
+	bool empty;
+
+	rcu_read_lock();
+	prog_array = rcu_dereference(cgrp->bpf.effective[attach_type]);
+	empty = bpf_prog_array_is_empty(prog_array);
+	rcu_read_unlock();
+
+	return empty;
+}
+
+static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen)
+{
+	if (unlikely(max_optlen < 0))
+		return -EINVAL;
+
+	if (unlikely(max_optlen > PAGE_SIZE)) {
+		/* We don't expose optvals that are greater than PAGE_SIZE
+		 * to the BPF program.
+		 */
+		max_optlen = PAGE_SIZE;
+	}
+
+	ctx->optval = kzalloc(max_optlen, GFP_USER);
+	if (!ctx->optval)
+		return -ENOMEM;
+
+	ctx->optval_end = ctx->optval + max_optlen;
+
+	return max_optlen;
+}
+
+static void sockopt_free_buf(struct bpf_sockopt_kern *ctx)
+{
+	kfree(ctx->optval);
+}
+
+int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
+				       int *optname, char __user *optval,
+				       int *optlen, char **kernel_optval)
+{
+	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+	struct bpf_sockopt_kern ctx = {
+		.sk = sk,
+		.level = *level,
+		.optname = *optname,
+	};
+	int ret, max_optlen;
+
+	/* Opportunistic check to see whether we have any BPF program
+	 * attached to the hook so we don't waste time allocating
+	 * memory and locking the socket.
+	 */
+	if (!cgroup_bpf_enabled ||
+	    __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_SETSOCKOPT))
+		return 0;
+
+	/* Allocate a bit more than the initial user buffer for
+	 * BPF program. The canonical use case is overriding
+	 * TCP_CONGESTION(nv) to TCP_CONGESTION(cubic).
+	 */
+	max_optlen = max_t(int, 16, *optlen);
+
+	max_optlen = sockopt_alloc_buf(&ctx, max_optlen);
+	if (max_optlen < 0)
+		return max_optlen;
+
+	ctx.optlen = *optlen;
+
+	if (copy_from_user(ctx.optval, optval, min(*optlen, max_optlen)) != 0) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	lock_sock(sk);
+	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_SETSOCKOPT],
+				 &ctx, BPF_PROG_RUN);
+	release_sock(sk);
+
+	if (!ret) {
+		ret = -EPERM;
+		goto out;
+	}
+
+	if (ctx.optlen == -1) {
+		/* optlen set to -1, bypass kernel */
+		ret = 1;
+	} else if (ctx.optlen > max_optlen || ctx.optlen < -1) {
+		/* optlen is out of bounds */
+		ret = -EFAULT;
+	} else {
+		/* optlen within bounds, run kernel handler */
+		ret = 0;
+
+		/* export any potential modifications */
+		*level = ctx.level;
+		*optname = ctx.optname;
+
+		/* optlen == 0 from BPF indicates that we should
+		 * use original userspace data.
+		 */
+		if (ctx.optlen != 0) {
+			*optlen = ctx.optlen;
+			*kernel_optval = ctx.optval;
+			/* export and don't free sockopt buf */
+			return 0;
+		}
+	}
+
+out:
+	sockopt_free_buf(&ctx);
+	return ret;
+}
+
+int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
+				       int optname, char __user *optval,
+				       int __user *optlen, int max_optlen,
+				       int retval)
+{
+	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+	struct bpf_sockopt_kern ctx = {
+		.sk = sk,
+		.level = level,
+		.optname = optname,
+		.retval = retval,
+	};
+	int ret;
+
+	/* Opportunistic check to see whether we have any BPF program
+	 * attached to the hook so we don't waste time allocating
+	 * memory and locking the socket.
+	 */
+	if (!cgroup_bpf_enabled ||
+	    __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT))
+		return retval;
+
+	ctx.optlen = max_optlen;
+
+	max_optlen = sockopt_alloc_buf(&ctx, max_optlen);
+	if (max_optlen < 0)
+		return max_optlen;
+
+	if (!retval) {
+		/* If kernel getsockopt finished successfully,
+		 * copy whatever was returned to the user back
+		 * into our temporary buffer. Set optlen to the
+		 * one that kernel returned as well to let
+		 * BPF programs inspect the value.
+		 */
+
+		if (get_user(ctx.optlen, optlen)) {
+			ret = -EFAULT;
+			goto out;
+		}
+
+		if (ctx.optlen < 0) {
+			ret = -EFAULT;
+			goto out;
+		}
+
+		if (copy_from_user(ctx.optval, optval,
+				   min(ctx.optlen, max_optlen)) != 0) {
+			ret = -EFAULT;
+			goto out;
+		}
+	}
+
+	lock_sock(sk);
+	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT],
+				 &ctx, BPF_PROG_RUN);
+	release_sock(sk);
+
+	if (!ret) {
+		ret = -EPERM;
+		goto out;
+	}
+
+	if (optval && (ctx.optlen > max_optlen || ctx.optlen < 0)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	/* BPF programs only allowed to set retval to 0, not some
+	 * arbitrary value.
+	 */
+	if (ctx.retval != 0 && ctx.retval != retval) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	if (ctx.optlen != 0) {
+		if (optval && copy_to_user(optval, ctx.optval, ctx.optlen)) {
+			ret = -EFAULT;
+			goto out;
+		}
+		if (put_user(ctx.optlen, optlen)) {
+			ret = -EFAULT;
+			goto out;
+		}
+	}
+
+	ret = ctx.retval;
+
+out:
+	sockopt_free_buf(&ctx);
+	return ret;
+}
+
+int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level,
+					    int optname, void *optval,
+					    int *optlen, int retval)
+{
+	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+	struct bpf_sockopt_kern ctx = {
+		.sk = sk,
+		.level = level,
+		.optname = optname,
+		.retval = retval,
+		.optlen = *optlen,
+		.optval = optval,
+		.optval_end = optval + *optlen,
+	};
+	int ret;
+
+	/* Note that __cgroup_bpf_run_filter_getsockopt doesn't copy
+	 * user data back into BPF buffer when reval != 0. This is
+	 * done as an optimization to avoid extra copy, assuming
+	 * kernel won't populate the data in case of an error.
+	 * Here we always pass the data and memset() should
+	 * be called if that data shouldn't be "exported".
+	 */
+
+	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT],
+				 &ctx, BPF_PROG_RUN);
+	if (!ret)
+		return -EPERM;
+
+	if (ctx.optlen > *optlen)
+		return -EFAULT;
+
+	/* BPF programs only allowed to set retval to 0, not some
+	 * arbitrary value.
+	 */
+	if (ctx.retval != 0 && ctx.retval != retval)
+		return -EFAULT;
+
+	/* BPF programs can shrink the buffer, export the modifications.
+	 */
+	if (ctx.optlen != 0)
+		*optlen = ctx.optlen;
+
+	return ctx.retval;
+}
+#endif
+
+static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp,
+			      size_t *lenp)
+{
+	ssize_t tmp_ret = 0, ret;
+
+	if (dir->header.parent) {
+		tmp_ret = sysctl_cpy_dir(dir->header.parent, bufp, lenp);
+		if (tmp_ret < 0)
+			return tmp_ret;
+	}
+
+	ret = strscpy(*bufp, dir->header.ctl_table[0].procname, *lenp);
+	if (ret < 0)
+		return ret;
+	*bufp += ret;
+	*lenp -= ret;
+	ret += tmp_ret;
+
+	/* Avoid leading slash. */
+	if (!ret)
+		return ret;
+
+	tmp_ret = strscpy(*bufp, "/", *lenp);
+	if (tmp_ret < 0)
+		return tmp_ret;
+	*bufp += tmp_ret;
+	*lenp -= tmp_ret;
+
+	return ret + tmp_ret;
+}
+
+BPF_CALL_4(bpf_sysctl_get_name, struct bpf_sysctl_kern *, ctx, char *, buf,
+	   size_t, buf_len, u64, flags)
+{
+	ssize_t tmp_ret = 0, ret;
+
+	if (!buf)
+		return -EINVAL;
+
+	if (!(flags & BPF_F_SYSCTL_BASE_NAME)) {
+		if (!ctx->head)
+			return -EINVAL;
+		tmp_ret = sysctl_cpy_dir(ctx->head->parent, &buf, &buf_len);
+		if (tmp_ret < 0)
+			return tmp_ret;
+	}
+
+	ret = strscpy(buf, ctx->table->procname, buf_len);
+
+	return ret < 0 ? ret : tmp_ret + ret;
+}
+
+static const struct bpf_func_proto bpf_sysctl_get_name_proto = {
+	.func		= bpf_sysctl_get_name,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+static int copy_sysctl_value(char *dst, size_t dst_len, char *src,
+			     size_t src_len)
+{
+	if (!dst)
+		return -EINVAL;
+
+	if (!dst_len)
+		return -E2BIG;
+
+	if (!src || !src_len) {
+		memset(dst, 0, dst_len);
+		return -EINVAL;
+	}
+
+	memcpy(dst, src, min(dst_len, src_len));
+
+	if (dst_len > src_len) {
+		memset(dst + src_len, '\0', dst_len - src_len);
+		return src_len;
+	}
+
+	dst[dst_len - 1] = '\0';
+
+	return -E2BIG;
+}
+
+BPF_CALL_3(bpf_sysctl_get_current_value, struct bpf_sysctl_kern *, ctx,
+	   char *, buf, size_t, buf_len)
+{
+	return copy_sysctl_value(buf, buf_len, ctx->cur_val, ctx->cur_len);
+}
+
+static const struct bpf_func_proto bpf_sysctl_get_current_value_proto = {
+	.func		= bpf_sysctl_get_current_value,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+};
+
+BPF_CALL_3(bpf_sysctl_get_new_value, struct bpf_sysctl_kern *, ctx, char *, buf,
+	   size_t, buf_len)
+{
+	if (!ctx->write) {
+		if (buf && buf_len)
+			memset(buf, '\0', buf_len);
+		return -EINVAL;
+	}
+	return copy_sysctl_value(buf, buf_len, ctx->new_val, ctx->new_len);
+}
+
+static const struct bpf_func_proto bpf_sysctl_get_new_value_proto = {
+	.func		= bpf_sysctl_get_new_value,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+};
+
+BPF_CALL_3(bpf_sysctl_set_new_value, struct bpf_sysctl_kern *, ctx,
+	   const char *, buf, size_t, buf_len)
+{
+	if (!ctx->write || !ctx->new_val || !ctx->new_len || !buf || !buf_len)
+		return -EINVAL;
+
+	if (buf_len > PAGE_SIZE - 1)
+		return -E2BIG;
+
+	memcpy(ctx->new_val, buf, buf_len);
+	ctx->new_len = buf_len;
+	ctx->new_updated = 1;
+
+	return 0;
+}
+
+static const struct bpf_func_proto bpf_sysctl_set_new_value_proto = {
+	.func		= bpf_sysctl_set_new_value,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+};
+
+static const struct bpf_func_proto *
+sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	switch (func_id) {
+	case BPF_FUNC_strtol:
+		return &bpf_strtol_proto;
+	case BPF_FUNC_strtoul:
+		return &bpf_strtoul_proto;
+	case BPF_FUNC_sysctl_get_name:
+		return &bpf_sysctl_get_name_proto;
+	case BPF_FUNC_sysctl_get_current_value:
+		return &bpf_sysctl_get_current_value_proto;
+	case BPF_FUNC_sysctl_get_new_value:
+		return &bpf_sysctl_get_new_value_proto;
+	case BPF_FUNC_sysctl_set_new_value:
+		return &bpf_sysctl_set_new_value_proto;
+	default:
+		return cgroup_base_func_proto(func_id, prog);
+	}
+}
+
+static bool sysctl_is_valid_access(int off, int size, enum bpf_access_type type,
+				   const struct bpf_prog *prog,
+				   struct bpf_insn_access_aux *info)
+{
+	const int size_default = sizeof(__u32);
+
+	if (off < 0 || off + size > sizeof(struct bpf_sysctl) || off % size)
+		return false;
+
+	switch (off) {
+	case bpf_ctx_range(struct bpf_sysctl, write):
+		if (type != BPF_READ)
+			return false;
+		bpf_ctx_record_field_size(info, size_default);
+		return bpf_ctx_narrow_access_ok(off, size, size_default);
+	case bpf_ctx_range(struct bpf_sysctl, file_pos):
+		if (type == BPF_READ) {
+			bpf_ctx_record_field_size(info, size_default);
+			return bpf_ctx_narrow_access_ok(off, size, size_default);
+		} else {
+			return size == size_default;
+		}
+	default:
+		return false;
+	}
+}
+
+static u32 sysctl_convert_ctx_access(enum bpf_access_type type,
+				     const struct bpf_insn *si,
+				     struct bpf_insn *insn_buf,
+				     struct bpf_prog *prog, u32 *target_size)
+{
+	struct bpf_insn *insn = insn_buf;
+	u32 read_size;
+
+	switch (si->off) {
+	case offsetof(struct bpf_sysctl, write):
+		*insn++ = BPF_LDX_MEM(
+			BPF_SIZE(si->code), si->dst_reg, si->src_reg,
+			bpf_target_off(struct bpf_sysctl_kern, write,
+				       sizeof_field(struct bpf_sysctl_kern,
+						    write),
+				       target_size));
+		break;
+	case offsetof(struct bpf_sysctl, file_pos):
+		/* ppos is a pointer so it should be accessed via indirect
+		 * loads and stores. Also for stores additional temporary
+		 * register is used since neither src_reg nor dst_reg can be
+		 * overridden.
+		 */
+		if (type == BPF_WRITE) {
+			int treg = BPF_REG_9;
+
+			if (si->src_reg == treg || si->dst_reg == treg)
+				--treg;
+			if (si->src_reg == treg || si->dst_reg == treg)
+				--treg;
+			*insn++ = BPF_STX_MEM(
+				BPF_DW, si->dst_reg, treg,
+				offsetof(struct bpf_sysctl_kern, tmp_reg));
+			*insn++ = BPF_LDX_MEM(
+				BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
+				treg, si->dst_reg,
+				offsetof(struct bpf_sysctl_kern, ppos));
+			*insn++ = BPF_STX_MEM(
+				BPF_SIZEOF(u32), treg, si->src_reg,
+				bpf_ctx_narrow_access_offset(
+					0, sizeof(u32), sizeof(loff_t)));
+			*insn++ = BPF_LDX_MEM(
+				BPF_DW, treg, si->dst_reg,
+				offsetof(struct bpf_sysctl_kern, tmp_reg));
+		} else {
+			*insn++ = BPF_LDX_MEM(
+				BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
+				si->dst_reg, si->src_reg,
+				offsetof(struct bpf_sysctl_kern, ppos));
+			read_size = bpf_size_to_bytes(BPF_SIZE(si->code));
+			*insn++ = BPF_LDX_MEM(
+				BPF_SIZE(si->code), si->dst_reg, si->dst_reg,
+				bpf_ctx_narrow_access_offset(
+					0, read_size, sizeof(loff_t)));
+		}
+		*target_size = sizeof(u32);
+		break;
+	}
+
+	return insn - insn_buf;
+}
+
+const struct bpf_verifier_ops cg_sysctl_verifier_ops = {
+	.get_func_proto		= sysctl_func_proto,
+	.is_valid_access	= sysctl_is_valid_access,
+	.convert_ctx_access	= sysctl_convert_ctx_access,
+};
+
+const struct bpf_prog_ops cg_sysctl_prog_ops = {
+};
+
+static const struct bpf_func_proto *
+cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	switch (func_id) {
+#ifdef CONFIG_NET
+	case BPF_FUNC_sk_storage_get:
+		return &bpf_sk_storage_get_proto;
+	case BPF_FUNC_sk_storage_delete:
+		return &bpf_sk_storage_delete_proto;
+#endif
+#ifdef CONFIG_INET
+	case BPF_FUNC_tcp_sock:
+		return &bpf_tcp_sock_proto;
+#endif
+	default:
+		return cgroup_base_func_proto(func_id, prog);
+	}
+}
+
+static bool cg_sockopt_is_valid_access(int off, int size,
+				       enum bpf_access_type type,
+				       const struct bpf_prog *prog,
+				       struct bpf_insn_access_aux *info)
+{
+	const int size_default = sizeof(__u32);
+
+	if (off < 0 || off >= sizeof(struct bpf_sockopt))
+		return false;
+
+	if (off % size != 0)
+		return false;
+
+	if (type == BPF_WRITE) {
+		switch (off) {
+		case offsetof(struct bpf_sockopt, retval):
+			if (size != size_default)
+				return false;
+			return prog->expected_attach_type ==
+				BPF_CGROUP_GETSOCKOPT;
+		case offsetof(struct bpf_sockopt, optname):
+			fallthrough;
+		case offsetof(struct bpf_sockopt, level):
+			if (size != size_default)
+				return false;
+			return prog->expected_attach_type ==
+				BPF_CGROUP_SETSOCKOPT;
+		case offsetof(struct bpf_sockopt, optlen):
+			return size == size_default;
+		default:
+			return false;
+		}
+	}
+
+	switch (off) {
+	case offsetof(struct bpf_sockopt, sk):
+		if (size != sizeof(__u64))
+			return false;
+		info->reg_type = PTR_TO_SOCKET;
+		break;
+	case offsetof(struct bpf_sockopt, optval):
+		if (size != sizeof(__u64))
+			return false;
+		info->reg_type = PTR_TO_PACKET;
+		break;
+	case offsetof(struct bpf_sockopt, optval_end):
+		if (size != sizeof(__u64))
+			return false;
+		info->reg_type = PTR_TO_PACKET_END;
+		break;
+	case offsetof(struct bpf_sockopt, retval):
+		if (size != size_default)
+			return false;
+		return prog->expected_attach_type == BPF_CGROUP_GETSOCKOPT;
+	default:
+		if (size != size_default)
+			return false;
+		break;
+	}
+	return true;
+}
+
+#define CG_SOCKOPT_ACCESS_FIELD(T, F)					\
+	T(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, F),			\
+	  si->dst_reg, si->src_reg,					\
+	  offsetof(struct bpf_sockopt_kern, F))
+
+static u32 cg_sockopt_convert_ctx_access(enum bpf_access_type type,
+					 const struct bpf_insn *si,
+					 struct bpf_insn *insn_buf,
+					 struct bpf_prog *prog,
+					 u32 *target_size)
+{
+	struct bpf_insn *insn = insn_buf;
+
+	switch (si->off) {
+	case offsetof(struct bpf_sockopt, sk):
+		*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, sk);
+		break;
+	case offsetof(struct bpf_sockopt, level):
+		if (type == BPF_WRITE)
+			*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, level);
+		else
+			*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, level);
+		break;
+	case offsetof(struct bpf_sockopt, optname):
+		if (type == BPF_WRITE)
+			*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, optname);
+		else
+			*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optname);
+		break;
+	case offsetof(struct bpf_sockopt, optlen):
+		if (type == BPF_WRITE)
+			*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, optlen);
+		else
+			*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optlen);
+		break;
+	case offsetof(struct bpf_sockopt, retval):
+		if (type == BPF_WRITE)
+			*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, retval);
+		else
+			*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, retval);
+		break;
+	case offsetof(struct bpf_sockopt, optval):
+		*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optval);
+		break;
+	case offsetof(struct bpf_sockopt, optval_end):
+		*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optval_end);
+		break;
+	}
+
+	return insn - insn_buf;
+}
+
+static int cg_sockopt_get_prologue(struct bpf_insn *insn_buf,
+				   bool direct_write,
+				   const struct bpf_prog *prog)
+{
+	/* Nothing to do for sockopt argument. The data is kzalloc'ated.
+	 */
+	return 0;
+}
+
+const struct bpf_verifier_ops cg_sockopt_verifier_ops = {
+	.get_func_proto		= cg_sockopt_func_proto,
+	.is_valid_access	= cg_sockopt_is_valid_access,
+	.convert_ctx_access	= cg_sockopt_convert_ctx_access,
+	.gen_prologue		= cg_sockopt_get_prologue,
+};
+
+const struct bpf_prog_ops cg_sockopt_prog_ops = {
+};
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
new file mode 100644
index 000000000..33ea6ab12
--- /dev/null
+++ b/kernel/bpf/core.c
@@ -0,0 +1,2358 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Linux Socket Filter - Kernel level socket filtering
+ *
+ * Based on the design of the Berkeley Packet Filter. The new
+ * internal format has been designed by PLUMgrid:
+ *
+ *	Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
+ *
+ * Authors:
+ *
+ *	Jay Schulist <jschlst@samba.org>
+ *	Alexei Starovoitov <ast@plumgrid.com>
+ *	Daniel Borkmann <dborkman@redhat.com>
+ *
+ * Andi Kleen - Fix a few bad bugs and races.
+ * Kris Katterjohn - Added many additional checks in bpf_check_classic()
+ */
+
+#include <uapi/linux/btf.h>
+#include <linux/filter.h>
+#include <linux/skbuff.h>
+#include <linux/vmalloc.h>
+#include <linux/random.h>
+#include <linux/moduleloader.h>
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/objtool.h>
+#include <linux/rbtree_latch.h>
+#include <linux/kallsyms.h>
+#include <linux/rcupdate.h>
+#include <linux/perf_event.h>
+#include <linux/extable.h>
+#include <linux/log2.h>
+#include <linux/nospec.h>
+
+#include <asm/barrier.h>
+#include <asm/unaligned.h>
+
+/* Registers */
+#define BPF_R0	regs[BPF_REG_0]
+#define BPF_R1	regs[BPF_REG_1]
+#define BPF_R2	regs[BPF_REG_2]
+#define BPF_R3	regs[BPF_REG_3]
+#define BPF_R4	regs[BPF_REG_4]
+#define BPF_R5	regs[BPF_REG_5]
+#define BPF_R6	regs[BPF_REG_6]
+#define BPF_R7	regs[BPF_REG_7]
+#define BPF_R8	regs[BPF_REG_8]
+#define BPF_R9	regs[BPF_REG_9]
+#define BPF_R10	regs[BPF_REG_10]
+
+/* Named registers */
+#define DST	regs[insn->dst_reg]
+#define SRC	regs[insn->src_reg]
+#define FP	regs[BPF_REG_FP]
+#define AX	regs[BPF_REG_AX]
+#define ARG1	regs[BPF_REG_ARG1]
+#define CTX	regs[BPF_REG_CTX]
+#define IMM	insn->imm
+
+/* No hurry in this branch
+ *
+ * Exported for the bpf jit load helper.
+ */
+void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
+{
+	u8 *ptr = NULL;
+
+	if (k >= SKF_NET_OFF) {
+		ptr = skb_network_header(skb) + k - SKF_NET_OFF;
+	} else if (k >= SKF_LL_OFF) {
+		if (unlikely(!skb_mac_header_was_set(skb)))
+			return NULL;
+		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
+	}
+	if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
+		return ptr;
+
+	return NULL;
+}
+
+struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
+{
+	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
+	struct bpf_prog_aux *aux;
+	struct bpf_prog *fp;
+
+	size = round_up(size, PAGE_SIZE);
+	fp = __vmalloc(size, gfp_flags);
+	if (fp == NULL)
+		return NULL;
+
+	aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
+	if (aux == NULL) {
+		vfree(fp);
+		return NULL;
+	}
+
+	fp->pages = size / PAGE_SIZE;
+	fp->aux = aux;
+	fp->aux->prog = fp;
+	fp->jit_requested = ebpf_jit_enabled();
+
+	INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
+	mutex_init(&fp->aux->used_maps_mutex);
+	mutex_init(&fp->aux->dst_mutex);
+
+	return fp;
+}
+
+struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
+{
+	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
+	struct bpf_prog *prog;
+	int cpu;
+
+	prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
+	if (!prog)
+		return NULL;
+
+	prog->aux->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
+	if (!prog->aux->stats) {
+		kfree(prog->aux);
+		vfree(prog);
+		return NULL;
+	}
+
+	for_each_possible_cpu(cpu) {
+		struct bpf_prog_stats *pstats;
+
+		pstats = per_cpu_ptr(prog->aux->stats, cpu);
+		u64_stats_init(&pstats->syncp);
+	}
+	return prog;
+}
+EXPORT_SYMBOL_GPL(bpf_prog_alloc);
+
+int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
+{
+	if (!prog->aux->nr_linfo || !prog->jit_requested)
+		return 0;
+
+	prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo,
+					 sizeof(*prog->aux->jited_linfo),
+					 GFP_KERNEL | __GFP_NOWARN);
+	if (!prog->aux->jited_linfo)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void bpf_prog_free_jited_linfo(struct bpf_prog *prog)
+{
+	kfree(prog->aux->jited_linfo);
+	prog->aux->jited_linfo = NULL;
+}
+
+void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog)
+{
+	if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0])
+		bpf_prog_free_jited_linfo(prog);
+}
+
+/* The jit engine is responsible to provide an array
+ * for insn_off to the jited_off mapping (insn_to_jit_off).
+ *
+ * The idx to this array is the insn_off.  Hence, the insn_off
+ * here is relative to the prog itself instead of the main prog.
+ * This array has one entry for each xlated bpf insn.
+ *
+ * jited_off is the byte off to the last byte of the jited insn.
+ *
+ * Hence, with
+ * insn_start:
+ *      The first bpf insn off of the prog.  The insn off
+ *      here is relative to the main prog.
+ *      e.g. if prog is a subprog, insn_start > 0
+ * linfo_idx:
+ *      The prog's idx to prog->aux->linfo and jited_linfo
+ *
+ * jited_linfo[linfo_idx] = prog->bpf_func
+ *
+ * For i > linfo_idx,
+ *
+ * jited_linfo[i] = prog->bpf_func +
+ *	insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
+ */
+void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
+			       const u32 *insn_to_jit_off)
+{
+	u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
+	const struct bpf_line_info *linfo;
+	void **jited_linfo;
+
+	if (!prog->aux->jited_linfo)
+		/* Userspace did not provide linfo */
+		return;
+
+	linfo_idx = prog->aux->linfo_idx;
+	linfo = &prog->aux->linfo[linfo_idx];
+	insn_start = linfo[0].insn_off;
+	insn_end = insn_start + prog->len;
+
+	jited_linfo = &prog->aux->jited_linfo[linfo_idx];
+	jited_linfo[0] = prog->bpf_func;
+
+	nr_linfo = prog->aux->nr_linfo - linfo_idx;
+
+	for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
+		/* The verifier ensures that linfo[i].insn_off is
+		 * strictly increasing
+		 */
+		jited_linfo[i] = prog->bpf_func +
+			insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
+}
+
+void bpf_prog_free_linfo(struct bpf_prog *prog)
+{
+	bpf_prog_free_jited_linfo(prog);
+	kvfree(prog->aux->linfo);
+}
+
+struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
+				  gfp_t gfp_extra_flags)
+{
+	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
+	struct bpf_prog *fp;
+	u32 pages, delta;
+	int ret;
+
+	size = round_up(size, PAGE_SIZE);
+	pages = size / PAGE_SIZE;
+	if (pages <= fp_old->pages)
+		return fp_old;
+
+	delta = pages - fp_old->pages;
+	ret = __bpf_prog_charge(fp_old->aux->user, delta);
+	if (ret)
+		return NULL;
+
+	fp = __vmalloc(size, gfp_flags);
+	if (fp == NULL) {
+		__bpf_prog_uncharge(fp_old->aux->user, delta);
+	} else {
+		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
+		fp->pages = pages;
+		fp->aux->prog = fp;
+
+		/* We keep fp->aux from fp_old around in the new
+		 * reallocated structure.
+		 */
+		fp_old->aux = NULL;
+		__bpf_prog_free(fp_old);
+	}
+
+	return fp;
+}
+
+void __bpf_prog_free(struct bpf_prog *fp)
+{
+	if (fp->aux) {
+		mutex_destroy(&fp->aux->used_maps_mutex);
+		mutex_destroy(&fp->aux->dst_mutex);
+		free_percpu(fp->aux->stats);
+		kfree(fp->aux->poke_tab);
+		kfree(fp->aux);
+	}
+	vfree(fp);
+}
+
+int bpf_prog_calc_tag(struct bpf_prog *fp)
+{
+	const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
+	u32 raw_size = bpf_prog_tag_scratch_size(fp);
+	u32 digest[SHA1_DIGEST_WORDS];
+	u32 ws[SHA1_WORKSPACE_WORDS];
+	u32 i, bsize, psize, blocks;
+	struct bpf_insn *dst;
+	bool was_ld_map;
+	u8 *raw, *todo;
+	__be32 *result;
+	__be64 *bits;
+
+	raw = vmalloc(raw_size);
+	if (!raw)
+		return -ENOMEM;
+
+	sha1_init(digest);
+	memset(ws, 0, sizeof(ws));
+
+	/* We need to take out the map fd for the digest calculation
+	 * since they are unstable from user space side.
+	 */
+	dst = (void *)raw;
+	for (i = 0, was_ld_map = false; i < fp->len; i++) {
+		dst[i] = fp->insnsi[i];
+		if (!was_ld_map &&
+		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
+		    (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
+		     dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
+			was_ld_map = true;
+			dst[i].imm = 0;
+		} else if (was_ld_map &&
+			   dst[i].code == 0 &&
+			   dst[i].dst_reg == 0 &&
+			   dst[i].src_reg == 0 &&
+			   dst[i].off == 0) {
+			was_ld_map = false;
+			dst[i].imm = 0;
+		} else {
+			was_ld_map = false;
+		}
+	}
+
+	psize = bpf_prog_insn_size(fp);
+	memset(&raw[psize], 0, raw_size - psize);
+	raw[psize++] = 0x80;
+
+	bsize  = round_up(psize, SHA1_BLOCK_SIZE);
+	blocks = bsize / SHA1_BLOCK_SIZE;
+	todo   = raw;
+	if (bsize - psize >= sizeof(__be64)) {
+		bits = (__be64 *)(todo + bsize - sizeof(__be64));
+	} else {
+		bits = (__be64 *)(todo + bsize + bits_offset);
+		blocks++;
+	}
+	*bits = cpu_to_be64((psize - 1) << 3);
+
+	while (blocks--) {
+		sha1_transform(digest, todo, ws);
+		todo += SHA1_BLOCK_SIZE;
+	}
+
+	result = (__force __be32 *)digest;
+	for (i = 0; i < SHA1_DIGEST_WORDS; i++)
+		result[i] = cpu_to_be32(digest[i]);
+	memcpy(fp->tag, result, sizeof(fp->tag));
+
+	vfree(raw);
+	return 0;
+}
+
+static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
+				s32 end_new, s32 curr, const bool probe_pass)
+{
+	const s64 imm_min = S32_MIN, imm_max = S32_MAX;
+	s32 delta = end_new - end_old;
+	s64 imm = insn->imm;
+
+	if (curr < pos && curr + imm + 1 >= end_old)
+		imm += delta;
+	else if (curr >= end_new && curr + imm + 1 < end_new)
+		imm -= delta;
+	if (imm < imm_min || imm > imm_max)
+		return -ERANGE;
+	if (!probe_pass)
+		insn->imm = imm;
+	return 0;
+}
+
+static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
+				s32 end_new, s32 curr, const bool probe_pass)
+{
+	const s32 off_min = S16_MIN, off_max = S16_MAX;
+	s32 delta = end_new - end_old;
+	s32 off = insn->off;
+
+	if (curr < pos && curr + off + 1 >= end_old)
+		off += delta;
+	else if (curr >= end_new && curr + off + 1 < end_new)
+		off -= delta;
+	if (off < off_min || off > off_max)
+		return -ERANGE;
+	if (!probe_pass)
+		insn->off = off;
+	return 0;
+}
+
+static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
+			    s32 end_new, const bool probe_pass)
+{
+	u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
+	struct bpf_insn *insn = prog->insnsi;
+	int ret = 0;
+
+	for (i = 0; i < insn_cnt; i++, insn++) {
+		u8 code;
+
+		/* In the probing pass we still operate on the original,
+		 * unpatched image in order to check overflows before we
+		 * do any other adjustments. Therefore skip the patchlet.
+		 */
+		if (probe_pass && i == pos) {
+			i = end_new;
+			insn = prog->insnsi + end_old;
+		}
+		code = insn->code;
+		if ((BPF_CLASS(code) != BPF_JMP &&
+		     BPF_CLASS(code) != BPF_JMP32) ||
+		    BPF_OP(code) == BPF_EXIT)
+			continue;
+		/* Adjust offset of jmps if we cross patch boundaries. */
+		if (BPF_OP(code) == BPF_CALL) {
+			if (insn->src_reg != BPF_PSEUDO_CALL)
+				continue;
+			ret = bpf_adj_delta_to_imm(insn, pos, end_old,
+						   end_new, i, probe_pass);
+		} else {
+			ret = bpf_adj_delta_to_off(insn, pos, end_old,
+						   end_new, i, probe_pass);
+		}
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
+{
+	struct bpf_line_info *linfo;
+	u32 i, nr_linfo;
+
+	nr_linfo = prog->aux->nr_linfo;
+	if (!nr_linfo || !delta)
+		return;
+
+	linfo = prog->aux->linfo;
+
+	for (i = 0; i < nr_linfo; i++)
+		if (off < linfo[i].insn_off)
+			break;
+
+	/* Push all off < linfo[i].insn_off by delta */
+	for (; i < nr_linfo; i++)
+		linfo[i].insn_off += delta;
+}
+
+struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
+				       const struct bpf_insn *patch, u32 len)
+{
+	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
+	const u32 cnt_max = S16_MAX;
+	struct bpf_prog *prog_adj;
+	int err;
+
+	/* Since our patchlet doesn't expand the image, we're done. */
+	if (insn_delta == 0) {
+		memcpy(prog->insnsi + off, patch, sizeof(*patch));
+		return prog;
+	}
+
+	insn_adj_cnt = prog->len + insn_delta;
+
+	/* Reject anything that would potentially let the insn->off
+	 * target overflow when we have excessive program expansions.
+	 * We need to probe here before we do any reallocation where
+	 * we afterwards may not fail anymore.
+	 */
+	if (insn_adj_cnt > cnt_max &&
+	    (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
+		return ERR_PTR(err);
+
+	/* Several new instructions need to be inserted. Make room
+	 * for them. Likely, there's no need for a new allocation as
+	 * last page could have large enough tailroom.
+	 */
+	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
+				    GFP_USER);
+	if (!prog_adj)
+		return ERR_PTR(-ENOMEM);
+
+	prog_adj->len = insn_adj_cnt;
+
+	/* Patching happens in 3 steps:
+	 *
+	 * 1) Move over tail of insnsi from next instruction onwards,
+	 *    so we can patch the single target insn with one or more
+	 *    new ones (patching is always from 1 to n insns, n > 0).
+	 * 2) Inject new instructions at the target location.
+	 * 3) Adjust branch offsets if necessary.
+	 */
+	insn_rest = insn_adj_cnt - off - len;
+
+	memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
+		sizeof(*patch) * insn_rest);
+	memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
+
+	/* We are guaranteed to not fail at this point, otherwise
+	 * the ship has sailed to reverse to the original state. An
+	 * overflow cannot happen at this point.
+	 */
+	BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
+
+	bpf_adj_linfo(prog_adj, off, insn_delta);
+
+	return prog_adj;
+}
+
+int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
+{
+	/* Branch offsets can't overflow when program is shrinking, no need
+	 * to call bpf_adj_branches(..., true) here
+	 */
+	memmove(prog->insnsi + off, prog->insnsi + off + cnt,
+		sizeof(struct bpf_insn) * (prog->len - off - cnt));
+	prog->len -= cnt;
+
+	return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
+}
+
+static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
+{
+	int i;
+
+	for (i = 0; i < fp->aux->func_cnt; i++)
+		bpf_prog_kallsyms_del(fp->aux->func[i]);
+}
+
+void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
+{
+	bpf_prog_kallsyms_del_subprogs(fp);
+	bpf_prog_kallsyms_del(fp);
+}
+
+#ifdef CONFIG_BPF_JIT
+/* All BPF JIT sysctl knobs here. */
+int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
+int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
+int bpf_jit_harden   __read_mostly;
+long bpf_jit_limit   __read_mostly;
+long bpf_jit_limit_max __read_mostly;
+
+static void
+bpf_prog_ksym_set_addr(struct bpf_prog *prog)
+{
+	const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog);
+	unsigned long addr = (unsigned long)hdr;
+
+	WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
+
+	prog->aux->ksym.start = (unsigned long) prog->bpf_func;
+	prog->aux->ksym.end   = addr + hdr->pages * PAGE_SIZE;
+}
+
+static void
+bpf_prog_ksym_set_name(struct bpf_prog *prog)
+{
+	char *sym = prog->aux->ksym.name;
+	const char *end = sym + KSYM_NAME_LEN;
+	const struct btf_type *type;
+	const char *func_name;
+
+	BUILD_BUG_ON(sizeof("bpf_prog_") +
+		     sizeof(prog->tag) * 2 +
+		     /* name has been null terminated.
+		      * We should need +1 for the '_' preceding
+		      * the name.  However, the null character
+		      * is double counted between the name and the
+		      * sizeof("bpf_prog_") above, so we omit
+		      * the +1 here.
+		      */
+		     sizeof(prog->aux->name) > KSYM_NAME_LEN);
+
+	sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
+	sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
+
+	/* prog->aux->name will be ignored if full btf name is available */
+	if (prog->aux->func_info_cnt) {
+		type = btf_type_by_id(prog->aux->btf,
+				      prog->aux->func_info[prog->aux->func_idx].type_id);
+		func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
+		snprintf(sym, (size_t)(end - sym), "_%s", func_name);
+		return;
+	}
+
+	if (prog->aux->name[0])
+		snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
+	else
+		*sym = 0;
+}
+
+static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
+{
+	return container_of(n, struct bpf_ksym, tnode)->start;
+}
+
+static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
+					  struct latch_tree_node *b)
+{
+	return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
+}
+
+static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
+{
+	unsigned long val = (unsigned long)key;
+	const struct bpf_ksym *ksym;
+
+	ksym = container_of(n, struct bpf_ksym, tnode);
+
+	if (val < ksym->start)
+		return -1;
+	/* Ensure that we detect return addresses as part of the program, when
+	 * the final instruction is a call for a program part of the stack
+	 * trace. Therefore, do val > ksym->end instead of val >= ksym->end.
+	 */
+	if (val > ksym->end)
+		return  1;
+
+	return 0;
+}
+
+static const struct latch_tree_ops bpf_tree_ops = {
+	.less	= bpf_tree_less,
+	.comp	= bpf_tree_comp,
+};
+
+static DEFINE_SPINLOCK(bpf_lock);
+static LIST_HEAD(bpf_kallsyms);
+static struct latch_tree_root bpf_tree __cacheline_aligned;
+
+void bpf_ksym_add(struct bpf_ksym *ksym)
+{
+	spin_lock_bh(&bpf_lock);
+	WARN_ON_ONCE(!list_empty(&ksym->lnode));
+	list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
+	latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
+	spin_unlock_bh(&bpf_lock);
+}
+
+static void __bpf_ksym_del(struct bpf_ksym *ksym)
+{
+	if (list_empty(&ksym->lnode))
+		return;
+
+	latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
+	list_del_rcu(&ksym->lnode);
+}
+
+void bpf_ksym_del(struct bpf_ksym *ksym)
+{
+	spin_lock_bh(&bpf_lock);
+	__bpf_ksym_del(ksym);
+	spin_unlock_bh(&bpf_lock);
+}
+
+static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
+{
+	return fp->jited && !bpf_prog_was_classic(fp);
+}
+
+static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp)
+{
+	return list_empty(&fp->aux->ksym.lnode) ||
+	       fp->aux->ksym.lnode.prev == LIST_POISON2;
+}
+
+void bpf_prog_kallsyms_add(struct bpf_prog *fp)
+{
+	if (!bpf_prog_kallsyms_candidate(fp) ||
+	    !bpf_capable())
+		return;
+
+	bpf_prog_ksym_set_addr(fp);
+	bpf_prog_ksym_set_name(fp);
+	fp->aux->ksym.prog = true;
+
+	bpf_ksym_add(&fp->aux->ksym);
+}
+
+void bpf_prog_kallsyms_del(struct bpf_prog *fp)
+{
+	if (!bpf_prog_kallsyms_candidate(fp))
+		return;
+
+	bpf_ksym_del(&fp->aux->ksym);
+}
+
+static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
+{
+	struct latch_tree_node *n;
+
+	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
+	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
+}
+
+const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
+				 unsigned long *off, char *sym)
+{
+	struct bpf_ksym *ksym;
+	char *ret = NULL;
+
+	rcu_read_lock();
+	ksym = bpf_ksym_find(addr);
+	if (ksym) {
+		unsigned long symbol_start = ksym->start;
+		unsigned long symbol_end = ksym->end;
+
+		strncpy(sym, ksym->name, KSYM_NAME_LEN);
+
+		ret = sym;
+		if (size)
+			*size = symbol_end - symbol_start;
+		if (off)
+			*off  = addr - symbol_start;
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+bool is_bpf_text_address(unsigned long addr)
+{
+	bool ret;
+
+	rcu_read_lock();
+	ret = bpf_ksym_find(addr) != NULL;
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
+{
+	struct bpf_ksym *ksym = bpf_ksym_find(addr);
+
+	return ksym && ksym->prog ?
+	       container_of(ksym, struct bpf_prog_aux, ksym)->prog :
+	       NULL;
+}
+
+const struct exception_table_entry *search_bpf_extables(unsigned long addr)
+{
+	const struct exception_table_entry *e = NULL;
+	struct bpf_prog *prog;
+
+	rcu_read_lock();
+	prog = bpf_prog_ksym_find(addr);
+	if (!prog)
+		goto out;
+	if (!prog->aux->num_exentries)
+		goto out;
+
+	e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
+out:
+	rcu_read_unlock();
+	return e;
+}
+
+int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
+		    char *sym)
+{
+	struct bpf_ksym *ksym;
+	unsigned int it = 0;
+	int ret = -ERANGE;
+
+	if (!bpf_jit_kallsyms_enabled())
+		return ret;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
+		if (it++ != symnum)
+			continue;
+
+		strncpy(sym, ksym->name, KSYM_NAME_LEN);
+
+		*value = ksym->start;
+		*type  = BPF_SYM_ELF_TYPE;
+
+		ret = 0;
+		break;
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
+				struct bpf_jit_poke_descriptor *poke)
+{
+	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
+	static const u32 poke_tab_max = 1024;
+	u32 slot = prog->aux->size_poke_tab;
+	u32 size = slot + 1;
+
+	if (size > poke_tab_max)
+		return -ENOSPC;
+	if (poke->tailcall_target || poke->tailcall_target_stable ||
+	    poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
+		return -EINVAL;
+
+	switch (poke->reason) {
+	case BPF_POKE_REASON_TAIL_CALL:
+		if (!poke->tail_call.map)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
+	if (!tab)
+		return -ENOMEM;
+
+	memcpy(&tab[slot], poke, sizeof(*poke));
+	prog->aux->size_poke_tab = size;
+	prog->aux->poke_tab = tab;
+
+	return slot;
+}
+
+static atomic_long_t bpf_jit_current;
+
+/* Can be overridden by an arch's JIT compiler if it has a custom,
+ * dedicated BPF backend memory area, or if neither of the two
+ * below apply.
+ */
+u64 __weak bpf_jit_alloc_exec_limit(void)
+{
+#if defined(MODULES_VADDR)
+	return MODULES_END - MODULES_VADDR;
+#else
+	return VMALLOC_END - VMALLOC_START;
+#endif
+}
+
+static int __init bpf_jit_charge_init(void)
+{
+	/* Only used as heuristic here to derive limit. */
+	bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
+	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
+					    PAGE_SIZE), LONG_MAX);
+	return 0;
+}
+pure_initcall(bpf_jit_charge_init);
+
+int bpf_jit_charge_modmem(u32 pages)
+{
+	if (atomic_long_add_return(pages, &bpf_jit_current) >
+	    (bpf_jit_limit >> PAGE_SHIFT)) {
+		if (!bpf_capable()) {
+			atomic_long_sub(pages, &bpf_jit_current);
+			return -EPERM;
+		}
+	}
+
+	return 0;
+}
+
+void bpf_jit_uncharge_modmem(u32 pages)
+{
+	atomic_long_sub(pages, &bpf_jit_current);
+}
+
+void *__weak bpf_jit_alloc_exec(unsigned long size)
+{
+	return module_alloc(size);
+}
+
+void __weak bpf_jit_free_exec(void *addr)
+{
+	module_memfree(addr);
+}
+
+struct bpf_binary_header *
+bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
+		     unsigned int alignment,
+		     bpf_jit_fill_hole_t bpf_fill_ill_insns)
+{
+	struct bpf_binary_header *hdr;
+	u32 size, hole, start, pages;
+
+	WARN_ON_ONCE(!is_power_of_2(alignment) ||
+		     alignment > BPF_IMAGE_ALIGNMENT);
+
+	/* Most of BPF filters are really small, but if some of them
+	 * fill a page, allow at least 128 extra bytes to insert a
+	 * random section of illegal instructions.
+	 */
+	size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
+	pages = size / PAGE_SIZE;
+
+	if (bpf_jit_charge_modmem(pages))
+		return NULL;
+	hdr = bpf_jit_alloc_exec(size);
+	if (!hdr) {
+		bpf_jit_uncharge_modmem(pages);
+		return NULL;
+	}
+
+	/* Fill space with illegal/arch-dep instructions. */
+	bpf_fill_ill_insns(hdr, size);
+
+	hdr->pages = pages;
+	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
+		     PAGE_SIZE - sizeof(*hdr));
+	start = (get_random_int() % hole) & ~(alignment - 1);
+
+	/* Leave a random number of instructions before BPF code. */
+	*image_ptr = &hdr->image[start];
+
+	return hdr;
+}
+
+void bpf_jit_binary_free(struct bpf_binary_header *hdr)
+{
+	u32 pages = hdr->pages;
+
+	bpf_jit_free_exec(hdr);
+	bpf_jit_uncharge_modmem(pages);
+}
+
+/* This symbol is only overridden by archs that have different
+ * requirements than the usual eBPF JITs, f.e. when they only
+ * implement cBPF JIT, do not set images read-only, etc.
+ */
+void __weak bpf_jit_free(struct bpf_prog *fp)
+{
+	if (fp->jited) {
+		struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
+
+		bpf_jit_binary_free(hdr);
+
+		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
+	}
+
+	bpf_prog_unlock_free(fp);
+}
+
+int bpf_jit_get_func_addr(const struct bpf_prog *prog,
+			  const struct bpf_insn *insn, bool extra_pass,
+			  u64 *func_addr, bool *func_addr_fixed)
+{
+	s16 off = insn->off;
+	s32 imm = insn->imm;
+	u8 *addr;
+
+	*func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
+	if (!*func_addr_fixed) {
+		/* Place-holder address till the last pass has collected
+		 * all addresses for JITed subprograms in which case we
+		 * can pick them up from prog->aux.
+		 */
+		if (!extra_pass)
+			addr = NULL;
+		else if (prog->aux->func &&
+			 off >= 0 && off < prog->aux->func_cnt)
+			addr = (u8 *)prog->aux->func[off]->bpf_func;
+		else
+			return -EINVAL;
+	} else {
+		/* Address of a BPF helper call. Since part of the core
+		 * kernel, it's always at a fixed location. __bpf_call_base
+		 * and the helper with imm relative to it are both in core
+		 * kernel.
+		 */
+		addr = (u8 *)__bpf_call_base + imm;
+	}
+
+	*func_addr = (unsigned long)addr;
+	return 0;
+}
+
+static int bpf_jit_blind_insn(const struct bpf_insn *from,
+			      const struct bpf_insn *aux,
+			      struct bpf_insn *to_buff,
+			      bool emit_zext)
+{
+	struct bpf_insn *to = to_buff;
+	u32 imm_rnd = get_random_int();
+	s16 off;
+
+	BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
+	BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
+
+	/* Constraints on AX register:
+	 *
+	 * AX register is inaccessible from user space. It is mapped in
+	 * all JITs, and used here for constant blinding rewrites. It is
+	 * typically "stateless" meaning its contents are only valid within
+	 * the executed instruction, but not across several instructions.
+	 * There are a few exceptions however which are further detailed
+	 * below.
+	 *
+	 * Constant blinding is only used by JITs, not in the interpreter.
+	 * The interpreter uses AX in some occasions as a local temporary
+	 * register e.g. in DIV or MOD instructions.
+	 *
+	 * In restricted circumstances, the verifier can also use the AX
+	 * register for rewrites as long as they do not interfere with
+	 * the above cases!
+	 */
+	if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
+		goto out;
+
+	if (from->imm == 0 &&
+	    (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
+	     from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
+		*to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
+		goto out;
+	}
+
+	switch (from->code) {
+	case BPF_ALU | BPF_ADD | BPF_K:
+	case BPF_ALU | BPF_SUB | BPF_K:
+	case BPF_ALU | BPF_AND | BPF_K:
+	case BPF_ALU | BPF_OR  | BPF_K:
+	case BPF_ALU | BPF_XOR | BPF_K:
+	case BPF_ALU | BPF_MUL | BPF_K:
+	case BPF_ALU | BPF_MOV | BPF_K:
+	case BPF_ALU | BPF_DIV | BPF_K:
+	case BPF_ALU | BPF_MOD | BPF_K:
+		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
+		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
+		*to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
+		break;
+
+	case BPF_ALU64 | BPF_ADD | BPF_K:
+	case BPF_ALU64 | BPF_SUB | BPF_K:
+	case BPF_ALU64 | BPF_AND | BPF_K:
+	case BPF_ALU64 | BPF_OR  | BPF_K:
+	case BPF_ALU64 | BPF_XOR | BPF_K:
+	case BPF_ALU64 | BPF_MUL | BPF_K:
+	case BPF_ALU64 | BPF_MOV | BPF_K:
+	case BPF_ALU64 | BPF_DIV | BPF_K:
+	case BPF_ALU64 | BPF_MOD | BPF_K:
+		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
+		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
+		*to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
+		break;
+
+	case BPF_JMP | BPF_JEQ  | BPF_K:
+	case BPF_JMP | BPF_JNE  | BPF_K:
+	case BPF_JMP | BPF_JGT  | BPF_K:
+	case BPF_JMP | BPF_JLT  | BPF_K:
+	case BPF_JMP | BPF_JGE  | BPF_K:
+	case BPF_JMP | BPF_JLE  | BPF_K:
+	case BPF_JMP | BPF_JSGT | BPF_K:
+	case BPF_JMP | BPF_JSLT | BPF_K:
+	case BPF_JMP | BPF_JSGE | BPF_K:
+	case BPF_JMP | BPF_JSLE | BPF_K:
+	case BPF_JMP | BPF_JSET | BPF_K:
+		/* Accommodate for extra offset in case of a backjump. */
+		off = from->off;
+		if (off < 0)
+			off -= 2;
+		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
+		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
+		*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
+		break;
+
+	case BPF_JMP32 | BPF_JEQ  | BPF_K:
+	case BPF_JMP32 | BPF_JNE  | BPF_K:
+	case BPF_JMP32 | BPF_JGT  | BPF_K:
+	case BPF_JMP32 | BPF_JLT  | BPF_K:
+	case BPF_JMP32 | BPF_JGE  | BPF_K:
+	case BPF_JMP32 | BPF_JLE  | BPF_K:
+	case BPF_JMP32 | BPF_JSGT | BPF_K:
+	case BPF_JMP32 | BPF_JSLT | BPF_K:
+	case BPF_JMP32 | BPF_JSGE | BPF_K:
+	case BPF_JMP32 | BPF_JSLE | BPF_K:
+	case BPF_JMP32 | BPF_JSET | BPF_K:
+		/* Accommodate for extra offset in case of a backjump. */
+		off = from->off;
+		if (off < 0)
+			off -= 2;
+		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
+		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
+		*to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
+				      off);
+		break;
+
+	case BPF_LD | BPF_IMM | BPF_DW:
+		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
+		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
+		*to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
+		*to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
+		break;
+	case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
+		*to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
+		*to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
+		if (emit_zext)
+			*to++ = BPF_ZEXT_REG(BPF_REG_AX);
+		*to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
+		break;
+
+	case BPF_ST | BPF_MEM | BPF_DW:
+	case BPF_ST | BPF_MEM | BPF_W:
+	case BPF_ST | BPF_MEM | BPF_H:
+	case BPF_ST | BPF_MEM | BPF_B:
+		*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
+		*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
+		*to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
+		break;
+	}
+out:
+	return to - to_buff;
+}
+
+static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
+					      gfp_t gfp_extra_flags)
+{
+	gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
+	struct bpf_prog *fp;
+
+	fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
+	if (fp != NULL) {
+		/* aux->prog still points to the fp_other one, so
+		 * when promoting the clone to the real program,
+		 * this still needs to be adapted.
+		 */
+		memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
+	}
+
+	return fp;
+}
+
+static void bpf_prog_clone_free(struct bpf_prog *fp)
+{
+	/* aux was stolen by the other clone, so we cannot free
+	 * it from this path! It will be freed eventually by the
+	 * other program on release.
+	 *
+	 * At this point, we don't need a deferred release since
+	 * clone is guaranteed to not be locked.
+	 */
+	fp->aux = NULL;
+	__bpf_prog_free(fp);
+}
+
+void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
+{
+	/* We have to repoint aux->prog to self, as we don't
+	 * know whether fp here is the clone or the original.
+	 */
+	fp->aux->prog = fp;
+	bpf_prog_clone_free(fp_other);
+}
+
+struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
+{
+	struct bpf_insn insn_buff[16], aux[2];
+	struct bpf_prog *clone, *tmp;
+	int insn_delta, insn_cnt;
+	struct bpf_insn *insn;
+	int i, rewritten;
+
+	if (!bpf_jit_blinding_enabled(prog) || prog->blinded)
+		return prog;
+
+	clone = bpf_prog_clone_create(prog, GFP_USER);
+	if (!clone)
+		return ERR_PTR(-ENOMEM);
+
+	insn_cnt = clone->len;
+	insn = clone->insnsi;
+
+	for (i = 0; i < insn_cnt; i++, insn++) {
+		/* We temporarily need to hold the original ld64 insn
+		 * so that we can still access the first part in the
+		 * second blinding run.
+		 */
+		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
+		    insn[1].code == 0)
+			memcpy(aux, insn, sizeof(aux));
+
+		rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
+						clone->aux->verifier_zext);
+		if (!rewritten)
+			continue;
+
+		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
+		if (IS_ERR(tmp)) {
+			/* Patching may have repointed aux->prog during
+			 * realloc from the original one, so we need to
+			 * fix it up here on error.
+			 */
+			bpf_jit_prog_release_other(prog, clone);
+			return tmp;
+		}
+
+		clone = tmp;
+		insn_delta = rewritten - 1;
+
+		/* Walk new program and skip insns we just inserted. */
+		insn = clone->insnsi + i + insn_delta;
+		insn_cnt += insn_delta;
+		i        += insn_delta;
+	}
+
+	clone->blinded = 1;
+	return clone;
+}
+#endif /* CONFIG_BPF_JIT */
+
+/* Base function for offset calculation. Needs to go into .text section,
+ * therefore keeping it non-static as well; will also be used by JITs
+ * anyway later on, so do not let the compiler omit it. This also needs
+ * to go into kallsyms for correlation from e.g. bpftool, so naming
+ * must not change.
+ */
+noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__bpf_call_base);
+
+/* All UAPI available opcodes. */
+#define BPF_INSN_MAP(INSN_2, INSN_3)		\
+	/* 32 bit ALU operations. */		\
+	/*   Register based. */			\
+	INSN_3(ALU, ADD,  X),			\
+	INSN_3(ALU, SUB,  X),			\
+	INSN_3(ALU, AND,  X),			\
+	INSN_3(ALU, OR,   X),			\
+	INSN_3(ALU, LSH,  X),			\
+	INSN_3(ALU, RSH,  X),			\
+	INSN_3(ALU, XOR,  X),			\
+	INSN_3(ALU, MUL,  X),			\
+	INSN_3(ALU, MOV,  X),			\
+	INSN_3(ALU, ARSH, X),			\
+	INSN_3(ALU, DIV,  X),			\
+	INSN_3(ALU, MOD,  X),			\
+	INSN_2(ALU, NEG),			\
+	INSN_3(ALU, END, TO_BE),		\
+	INSN_3(ALU, END, TO_LE),		\
+	/*   Immediate based. */		\
+	INSN_3(ALU, ADD,  K),			\
+	INSN_3(ALU, SUB,  K),			\
+	INSN_3(ALU, AND,  K),			\
+	INSN_3(ALU, OR,   K),			\
+	INSN_3(ALU, LSH,  K),			\
+	INSN_3(ALU, RSH,  K),			\
+	INSN_3(ALU, XOR,  K),			\
+	INSN_3(ALU, MUL,  K),			\
+	INSN_3(ALU, MOV,  K),			\
+	INSN_3(ALU, ARSH, K),			\
+	INSN_3(ALU, DIV,  K),			\
+	INSN_3(ALU, MOD,  K),			\
+	/* 64 bit ALU operations. */		\
+	/*   Register based. */			\
+	INSN_3(ALU64, ADD,  X),			\
+	INSN_3(ALU64, SUB,  X),			\
+	INSN_3(ALU64, AND,  X),			\
+	INSN_3(ALU64, OR,   X),			\
+	INSN_3(ALU64, LSH,  X),			\
+	INSN_3(ALU64, RSH,  X),			\
+	INSN_3(ALU64, XOR,  X),			\
+	INSN_3(ALU64, MUL,  X),			\
+	INSN_3(ALU64, MOV,  X),			\
+	INSN_3(ALU64, ARSH, X),			\
+	INSN_3(ALU64, DIV,  X),			\
+	INSN_3(ALU64, MOD,  X),			\
+	INSN_2(ALU64, NEG),			\
+	/*   Immediate based. */		\
+	INSN_3(ALU64, ADD,  K),			\
+	INSN_3(ALU64, SUB,  K),			\
+	INSN_3(ALU64, AND,  K),			\
+	INSN_3(ALU64, OR,   K),			\
+	INSN_3(ALU64, LSH,  K),			\
+	INSN_3(ALU64, RSH,  K),			\
+	INSN_3(ALU64, XOR,  K),			\
+	INSN_3(ALU64, MUL,  K),			\
+	INSN_3(ALU64, MOV,  K),			\
+	INSN_3(ALU64, ARSH, K),			\
+	INSN_3(ALU64, DIV,  K),			\
+	INSN_3(ALU64, MOD,  K),			\
+	/* Call instruction. */			\
+	INSN_2(JMP, CALL),			\
+	/* Exit instruction. */			\
+	INSN_2(JMP, EXIT),			\
+	/* 32-bit Jump instructions. */		\
+	/*   Register based. */			\
+	INSN_3(JMP32, JEQ,  X),			\
+	INSN_3(JMP32, JNE,  X),			\
+	INSN_3(JMP32, JGT,  X),			\
+	INSN_3(JMP32, JLT,  X),			\
+	INSN_3(JMP32, JGE,  X),			\
+	INSN_3(JMP32, JLE,  X),			\
+	INSN_3(JMP32, JSGT, X),			\
+	INSN_3(JMP32, JSLT, X),			\
+	INSN_3(JMP32, JSGE, X),			\
+	INSN_3(JMP32, JSLE, X),			\
+	INSN_3(JMP32, JSET, X),			\
+	/*   Immediate based. */		\
+	INSN_3(JMP32, JEQ,  K),			\
+	INSN_3(JMP32, JNE,  K),			\
+	INSN_3(JMP32, JGT,  K),			\
+	INSN_3(JMP32, JLT,  K),			\
+	INSN_3(JMP32, JGE,  K),			\
+	INSN_3(JMP32, JLE,  K),			\
+	INSN_3(JMP32, JSGT, K),			\
+	INSN_3(JMP32, JSLT, K),			\
+	INSN_3(JMP32, JSGE, K),			\
+	INSN_3(JMP32, JSLE, K),			\
+	INSN_3(JMP32, JSET, K),			\
+	/* Jump instructions. */		\
+	/*   Register based. */			\
+	INSN_3(JMP, JEQ,  X),			\
+	INSN_3(JMP, JNE,  X),			\
+	INSN_3(JMP, JGT,  X),			\
+	INSN_3(JMP, JLT,  X),			\
+	INSN_3(JMP, JGE,  X),			\
+	INSN_3(JMP, JLE,  X),			\
+	INSN_3(JMP, JSGT, X),			\
+	INSN_3(JMP, JSLT, X),			\
+	INSN_3(JMP, JSGE, X),			\
+	INSN_3(JMP, JSLE, X),			\
+	INSN_3(JMP, JSET, X),			\
+	/*   Immediate based. */		\
+	INSN_3(JMP, JEQ,  K),			\
+	INSN_3(JMP, JNE,  K),			\
+	INSN_3(JMP, JGT,  K),			\
+	INSN_3(JMP, JLT,  K),			\
+	INSN_3(JMP, JGE,  K),			\
+	INSN_3(JMP, JLE,  K),			\
+	INSN_3(JMP, JSGT, K),			\
+	INSN_3(JMP, JSLT, K),			\
+	INSN_3(JMP, JSGE, K),			\
+	INSN_3(JMP, JSLE, K),			\
+	INSN_3(JMP, JSET, K),			\
+	INSN_2(JMP, JA),			\
+	/* Store instructions. */		\
+	/*   Register based. */			\
+	INSN_3(STX, MEM,  B),			\
+	INSN_3(STX, MEM,  H),			\
+	INSN_3(STX, MEM,  W),			\
+	INSN_3(STX, MEM,  DW),			\
+	INSN_3(STX, XADD, W),			\
+	INSN_3(STX, XADD, DW),			\
+	/*   Immediate based. */		\
+	INSN_3(ST, MEM, B),			\
+	INSN_3(ST, MEM, H),			\
+	INSN_3(ST, MEM, W),			\
+	INSN_3(ST, MEM, DW),			\
+	/* Load instructions. */		\
+	/*   Register based. */			\
+	INSN_3(LDX, MEM, B),			\
+	INSN_3(LDX, MEM, H),			\
+	INSN_3(LDX, MEM, W),			\
+	INSN_3(LDX, MEM, DW),			\
+	/*   Immediate based. */		\
+	INSN_3(LD, IMM, DW)
+
+bool bpf_opcode_in_insntable(u8 code)
+{
+#define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
+#define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
+	static const bool public_insntable[256] = {
+		[0 ... 255] = false,
+		/* Now overwrite non-defaults ... */
+		BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
+		/* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
+		[BPF_LD | BPF_ABS | BPF_B] = true,
+		[BPF_LD | BPF_ABS | BPF_H] = true,
+		[BPF_LD | BPF_ABS | BPF_W] = true,
+		[BPF_LD | BPF_IND | BPF_B] = true,
+		[BPF_LD | BPF_IND | BPF_H] = true,
+		[BPF_LD | BPF_IND | BPF_W] = true,
+	};
+#undef BPF_INSN_3_TBL
+#undef BPF_INSN_2_TBL
+	return public_insntable[code];
+}
+
+#ifndef CONFIG_BPF_JIT_ALWAYS_ON
+u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
+{
+	memset(dst, 0, size);
+	return -EFAULT;
+}
+
+/**
+ *	__bpf_prog_run - run eBPF program on a given context
+ *	@regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
+ *	@insn: is the array of eBPF instructions
+ *	@stack: is the eBPF storage stack
+ *
+ * Decode and execute eBPF instructions.
+ */
+static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
+{
+#define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
+#define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
+	static const void * const jumptable[256] __annotate_jump_table = {
+		[0 ... 255] = &&default_label,
+		/* Now overwrite non-defaults ... */
+		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
+		/* Non-UAPI available opcodes. */
+		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
+		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
+		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
+		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
+		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
+		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
+		[BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
+	};
+#undef BPF_INSN_3_LBL
+#undef BPF_INSN_2_LBL
+	u32 tail_call_cnt = 0;
+
+#define CONT	 ({ insn++; goto select_insn; })
+#define CONT_JMP ({ insn++; goto select_insn; })
+
+select_insn:
+	goto *jumptable[insn->code];
+
+	/* Explicitly mask the register-based shift amounts with 63 or 31
+	 * to avoid undefined behavior. Normally this won't affect the
+	 * generated code, for example, in case of native 64 bit archs such
+	 * as x86-64 or arm64, the compiler is optimizing the AND away for
+	 * the interpreter. In case of JITs, each of the JIT backends compiles
+	 * the BPF shift operations to machine instructions which produce
+	 * implementation-defined results in such a case; the resulting
+	 * contents of the register may be arbitrary, but program behaviour
+	 * as a whole remains defined. In other words, in case of JIT backends,
+	 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
+	 */
+	/* ALU (shifts) */
+#define SHT(OPCODE, OP)					\
+	ALU64_##OPCODE##_X:				\
+		DST = DST OP (SRC & 63);		\
+		CONT;					\
+	ALU_##OPCODE##_X:				\
+		DST = (u32) DST OP ((u32) SRC & 31);	\
+		CONT;					\
+	ALU64_##OPCODE##_K:				\
+		DST = DST OP IMM;			\
+		CONT;					\
+	ALU_##OPCODE##_K:				\
+		DST = (u32) DST OP (u32) IMM;		\
+		CONT;
+	/* ALU (rest) */
+#define ALU(OPCODE, OP)					\
+	ALU64_##OPCODE##_X:				\
+		DST = DST OP SRC;			\
+		CONT;					\
+	ALU_##OPCODE##_X:				\
+		DST = (u32) DST OP (u32) SRC;		\
+		CONT;					\
+	ALU64_##OPCODE##_K:				\
+		DST = DST OP IMM;			\
+		CONT;					\
+	ALU_##OPCODE##_K:				\
+		DST = (u32) DST OP (u32) IMM;		\
+		CONT;
+	ALU(ADD,  +)
+	ALU(SUB,  -)
+	ALU(AND,  &)
+	ALU(OR,   |)
+	ALU(XOR,  ^)
+	ALU(MUL,  *)
+	SHT(LSH, <<)
+	SHT(RSH, >>)
+#undef SHT
+#undef ALU
+	ALU_NEG:
+		DST = (u32) -DST;
+		CONT;
+	ALU64_NEG:
+		DST = -DST;
+		CONT;
+	ALU_MOV_X:
+		DST = (u32) SRC;
+		CONT;
+	ALU_MOV_K:
+		DST = (u32) IMM;
+		CONT;
+	ALU64_MOV_X:
+		DST = SRC;
+		CONT;
+	ALU64_MOV_K:
+		DST = IMM;
+		CONT;
+	LD_IMM_DW:
+		DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
+		insn++;
+		CONT;
+	ALU_ARSH_X:
+		DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
+		CONT;
+	ALU_ARSH_K:
+		DST = (u64) (u32) (((s32) DST) >> IMM);
+		CONT;
+	ALU64_ARSH_X:
+		(*(s64 *) &DST) >>= (SRC & 63);
+		CONT;
+	ALU64_ARSH_K:
+		(*(s64 *) &DST) >>= IMM;
+		CONT;
+	ALU64_MOD_X:
+		div64_u64_rem(DST, SRC, &AX);
+		DST = AX;
+		CONT;
+	ALU_MOD_X:
+		AX = (u32) DST;
+		DST = do_div(AX, (u32) SRC);
+		CONT;
+	ALU64_MOD_K:
+		div64_u64_rem(DST, IMM, &AX);
+		DST = AX;
+		CONT;
+	ALU_MOD_K:
+		AX = (u32) DST;
+		DST = do_div(AX, (u32) IMM);
+		CONT;
+	ALU64_DIV_X:
+		DST = div64_u64(DST, SRC);
+		CONT;
+	ALU_DIV_X:
+		AX = (u32) DST;
+		do_div(AX, (u32) SRC);
+		DST = (u32) AX;
+		CONT;
+	ALU64_DIV_K:
+		DST = div64_u64(DST, IMM);
+		CONT;
+	ALU_DIV_K:
+		AX = (u32) DST;
+		do_div(AX, (u32) IMM);
+		DST = (u32) AX;
+		CONT;
+	ALU_END_TO_BE:
+		switch (IMM) {
+		case 16:
+			DST = (__force u16) cpu_to_be16(DST);
+			break;
+		case 32:
+			DST = (__force u32) cpu_to_be32(DST);
+			break;
+		case 64:
+			DST = (__force u64) cpu_to_be64(DST);
+			break;
+		}
+		CONT;
+	ALU_END_TO_LE:
+		switch (IMM) {
+		case 16:
+			DST = (__force u16) cpu_to_le16(DST);
+			break;
+		case 32:
+			DST = (__force u32) cpu_to_le32(DST);
+			break;
+		case 64:
+			DST = (__force u64) cpu_to_le64(DST);
+			break;
+		}
+		CONT;
+
+	/* CALL */
+	JMP_CALL:
+		/* Function call scratches BPF_R1-BPF_R5 registers,
+		 * preserves BPF_R6-BPF_R9, and stores return value
+		 * into BPF_R0.
+		 */
+		BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
+						       BPF_R4, BPF_R5);
+		CONT;
+
+	JMP_CALL_ARGS:
+		BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
+							    BPF_R3, BPF_R4,
+							    BPF_R5,
+							    insn + insn->off + 1);
+		CONT;
+
+	JMP_TAIL_CALL: {
+		struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
+		struct bpf_array *array = container_of(map, struct bpf_array, map);
+		struct bpf_prog *prog;
+		u32 index = BPF_R3;
+
+		if (unlikely(index >= array->map.max_entries))
+			goto out;
+		if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
+			goto out;
+
+		tail_call_cnt++;
+
+		prog = READ_ONCE(array->ptrs[index]);
+		if (!prog)
+			goto out;
+
+		/* ARG1 at this point is guaranteed to point to CTX from
+		 * the verifier side due to the fact that the tail call is
+		 * handled like a helper, that is, bpf_tail_call_proto,
+		 * where arg1_type is ARG_PTR_TO_CTX.
+		 */
+		insn = prog->insnsi;
+		goto select_insn;
+out:
+		CONT;
+	}
+	JMP_JA:
+		insn += insn->off;
+		CONT;
+	JMP_EXIT:
+		return BPF_R0;
+	/* JMP */
+#define COND_JMP(SIGN, OPCODE, CMP_OP)				\
+	JMP_##OPCODE##_X:					\
+		if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {	\
+			insn += insn->off;			\
+			CONT_JMP;				\
+		}						\
+		CONT;						\
+	JMP32_##OPCODE##_X:					\
+		if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {	\
+			insn += insn->off;			\
+			CONT_JMP;				\
+		}						\
+		CONT;						\
+	JMP_##OPCODE##_K:					\
+		if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {	\
+			insn += insn->off;			\
+			CONT_JMP;				\
+		}						\
+		CONT;						\
+	JMP32_##OPCODE##_K:					\
+		if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {	\
+			insn += insn->off;			\
+			CONT_JMP;				\
+		}						\
+		CONT;
+	COND_JMP(u, JEQ, ==)
+	COND_JMP(u, JNE, !=)
+	COND_JMP(u, JGT, >)
+	COND_JMP(u, JLT, <)
+	COND_JMP(u, JGE, >=)
+	COND_JMP(u, JLE, <=)
+	COND_JMP(u, JSET, &)
+	COND_JMP(s, JSGT, >)
+	COND_JMP(s, JSLT, <)
+	COND_JMP(s, JSGE, >=)
+	COND_JMP(s, JSLE, <=)
+#undef COND_JMP
+	/* ST, STX and LDX*/
+	ST_NOSPEC:
+		/* Speculation barrier for mitigating Speculative Store Bypass.
+		 * In case of arm64, we rely on the firmware mitigation as
+		 * controlled via the ssbd kernel parameter. Whenever the
+		 * mitigation is enabled, it works for all of the kernel code
+		 * with no need to provide any additional instructions here.
+		 * In case of x86, we use 'lfence' insn for mitigation. We
+		 * reuse preexisting logic from Spectre v1 mitigation that
+		 * happens to produce the required code on x86 for v4 as well.
+		 */
+		barrier_nospec();
+		CONT;
+#define LDST(SIZEOP, SIZE)						\
+	STX_MEM_##SIZEOP:						\
+		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
+		CONT;							\
+	ST_MEM_##SIZEOP:						\
+		*(SIZE *)(unsigned long) (DST + insn->off) = IMM;	\
+		CONT;							\
+	LDX_MEM_##SIZEOP:						\
+		DST = *(SIZE *)(unsigned long) (SRC + insn->off);	\
+		CONT;							\
+	LDX_PROBE_MEM_##SIZEOP:						\
+		bpf_probe_read_kernel(&DST, sizeof(SIZE),		\
+				      (const void *)(long) (SRC + insn->off));	\
+		DST = *((SIZE *)&DST);					\
+		CONT;
+
+	LDST(B,   u8)
+	LDST(H,  u16)
+	LDST(W,  u32)
+	LDST(DW, u64)
+#undef LDST
+
+	STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
+		atomic_add((u32) SRC, (atomic_t *)(unsigned long)
+			   (DST + insn->off));
+		CONT;
+	STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
+		atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
+			     (DST + insn->off));
+		CONT;
+
+	default_label:
+		/* If we ever reach this, we have a bug somewhere. Die hard here
+		 * instead of just returning 0; we could be somewhere in a subprog,
+		 * so execution could continue otherwise which we do /not/ want.
+		 *
+		 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
+		 */
+		pr_warn("BPF interpreter: unknown opcode %02x\n", insn->code);
+		BUG_ON(1);
+		return 0;
+}
+
+#define PROG_NAME(stack_size) __bpf_prog_run##stack_size
+#define DEFINE_BPF_PROG_RUN(stack_size) \
+static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
+{ \
+	u64 stack[stack_size / sizeof(u64)]; \
+	u64 regs[MAX_BPF_EXT_REG]; \
+\
+	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
+	ARG1 = (u64) (unsigned long) ctx; \
+	return ___bpf_prog_run(regs, insn, stack); \
+}
+
+#define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
+#define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
+static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
+				      const struct bpf_insn *insn) \
+{ \
+	u64 stack[stack_size / sizeof(u64)]; \
+	u64 regs[MAX_BPF_EXT_REG]; \
+\
+	FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
+	BPF_R1 = r1; \
+	BPF_R2 = r2; \
+	BPF_R3 = r3; \
+	BPF_R4 = r4; \
+	BPF_R5 = r5; \
+	return ___bpf_prog_run(regs, insn, stack); \
+}
+
+#define EVAL1(FN, X) FN(X)
+#define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
+#define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
+#define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
+#define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
+#define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
+
+EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
+EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
+EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
+
+EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
+EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
+EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
+
+#define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
+
+static unsigned int (*interpreters[])(const void *ctx,
+				      const struct bpf_insn *insn) = {
+EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
+EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
+EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
+};
+#undef PROG_NAME_LIST
+#define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
+static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
+				  const struct bpf_insn *insn) = {
+EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
+EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
+EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
+};
+#undef PROG_NAME_LIST
+
+void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
+{
+	stack_depth = max_t(u32, stack_depth, 1);
+	insn->off = (s16) insn->imm;
+	insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
+		__bpf_call_base_args;
+	insn->code = BPF_JMP | BPF_CALL_ARGS;
+}
+
+#else
+static unsigned int __bpf_prog_ret0_warn(const void *ctx,
+					 const struct bpf_insn *insn)
+{
+	/* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
+	 * is not working properly, so warn about it!
+	 */
+	WARN_ON_ONCE(1);
+	return 0;
+}
+#endif
+
+bool bpf_prog_array_compatible(struct bpf_array *array,
+			       const struct bpf_prog *fp)
+{
+	bool ret;
+
+	if (fp->kprobe_override)
+		return false;
+
+	spin_lock(&array->aux->owner.lock);
+
+	if (!array->aux->owner.type) {
+		/* There's no owner yet where we could check for
+		 * compatibility.
+		 */
+		array->aux->owner.type  = fp->type;
+		array->aux->owner.jited = fp->jited;
+		ret = true;
+	} else {
+		ret = array->aux->owner.type  == fp->type &&
+		      array->aux->owner.jited == fp->jited;
+	}
+	spin_unlock(&array->aux->owner.lock);
+	return ret;
+}
+
+static int bpf_check_tail_call(const struct bpf_prog *fp)
+{
+	struct bpf_prog_aux *aux = fp->aux;
+	int i, ret = 0;
+
+	mutex_lock(&aux->used_maps_mutex);
+	for (i = 0; i < aux->used_map_cnt; i++) {
+		struct bpf_map *map = aux->used_maps[i];
+		struct bpf_array *array;
+
+		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
+			continue;
+
+		array = container_of(map, struct bpf_array, map);
+		if (!bpf_prog_array_compatible(array, fp)) {
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+
+out:
+	mutex_unlock(&aux->used_maps_mutex);
+	return ret;
+}
+
+static void bpf_prog_select_func(struct bpf_prog *fp)
+{
+#ifndef CONFIG_BPF_JIT_ALWAYS_ON
+	u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
+
+	fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
+#else
+	fp->bpf_func = __bpf_prog_ret0_warn;
+#endif
+}
+
+/**
+ *	bpf_prog_select_runtime - select exec runtime for BPF program
+ *	@fp: bpf_prog populated with internal BPF program
+ *	@err: pointer to error variable
+ *
+ * Try to JIT eBPF program, if JIT is not available, use interpreter.
+ * The BPF program will be executed via BPF_PROG_RUN() macro.
+ */
+struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
+{
+	/* In case of BPF to BPF calls, verifier did all the prep
+	 * work with regards to JITing, etc.
+	 */
+	if (fp->bpf_func)
+		goto finalize;
+
+	bpf_prog_select_func(fp);
+
+	/* eBPF JITs can rewrite the program in case constant
+	 * blinding is active. However, in case of error during
+	 * blinding, bpf_int_jit_compile() must always return a
+	 * valid program, which in this case would simply not
+	 * be JITed, but falls back to the interpreter.
+	 */
+	if (!bpf_prog_is_dev_bound(fp->aux)) {
+		*err = bpf_prog_alloc_jited_linfo(fp);
+		if (*err)
+			return fp;
+
+		fp = bpf_int_jit_compile(fp);
+		if (!fp->jited) {
+			bpf_prog_free_jited_linfo(fp);
+#ifdef CONFIG_BPF_JIT_ALWAYS_ON
+			*err = -ENOTSUPP;
+			return fp;
+#endif
+		} else {
+			bpf_prog_free_unused_jited_linfo(fp);
+		}
+	} else {
+		*err = bpf_prog_offload_compile(fp);
+		if (*err)
+			return fp;
+	}
+
+finalize:
+	bpf_prog_lock_ro(fp);
+
+	/* The tail call compatibility check can only be done at
+	 * this late stage as we need to determine, if we deal
+	 * with JITed or non JITed program concatenations and not
+	 * all eBPF JITs might immediately support all features.
+	 */
+	*err = bpf_check_tail_call(fp);
+
+	return fp;
+}
+EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
+
+static unsigned int __bpf_prog_ret1(const void *ctx,
+				    const struct bpf_insn *insn)
+{
+	return 1;
+}
+
+static struct bpf_prog_dummy {
+	struct bpf_prog prog;
+} dummy_bpf_prog = {
+	.prog = {
+		.bpf_func = __bpf_prog_ret1,
+	},
+};
+
+/* to avoid allocating empty bpf_prog_array for cgroups that
+ * don't have bpf program attached use one global 'empty_prog_array'
+ * It will not be modified the caller of bpf_prog_array_alloc()
+ * (since caller requested prog_cnt == 0)
+ * that pointer should be 'freed' by bpf_prog_array_free()
+ */
+static struct {
+	struct bpf_prog_array hdr;
+	struct bpf_prog *null_prog;
+} empty_prog_array = {
+	.null_prog = NULL,
+};
+
+struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
+{
+	if (prog_cnt)
+		return kzalloc(sizeof(struct bpf_prog_array) +
+			       sizeof(struct bpf_prog_array_item) *
+			       (prog_cnt + 1),
+			       flags);
+
+	return &empty_prog_array.hdr;
+}
+
+void bpf_prog_array_free(struct bpf_prog_array *progs)
+{
+	if (!progs || progs == &empty_prog_array.hdr)
+		return;
+	kfree_rcu(progs, rcu);
+}
+
+int bpf_prog_array_length(struct bpf_prog_array *array)
+{
+	struct bpf_prog_array_item *item;
+	u32 cnt = 0;
+
+	for (item = array->items; item->prog; item++)
+		if (item->prog != &dummy_bpf_prog.prog)
+			cnt++;
+	return cnt;
+}
+
+bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
+{
+	struct bpf_prog_array_item *item;
+
+	for (item = array->items; item->prog; item++)
+		if (item->prog != &dummy_bpf_prog.prog)
+			return false;
+	return true;
+}
+
+static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
+				     u32 *prog_ids,
+				     u32 request_cnt)
+{
+	struct bpf_prog_array_item *item;
+	int i = 0;
+
+	for (item = array->items; item->prog; item++) {
+		if (item->prog == &dummy_bpf_prog.prog)
+			continue;
+		prog_ids[i] = item->prog->aux->id;
+		if (++i == request_cnt) {
+			item++;
+			break;
+		}
+	}
+
+	return !!(item->prog);
+}
+
+int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
+				__u32 __user *prog_ids, u32 cnt)
+{
+	unsigned long err = 0;
+	bool nospc;
+	u32 *ids;
+
+	/* users of this function are doing:
+	 * cnt = bpf_prog_array_length();
+	 * if (cnt > 0)
+	 *     bpf_prog_array_copy_to_user(..., cnt);
+	 * so below kcalloc doesn't need extra cnt > 0 check.
+	 */
+	ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
+	if (!ids)
+		return -ENOMEM;
+	nospc = bpf_prog_array_copy_core(array, ids, cnt);
+	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
+	kfree(ids);
+	if (err)
+		return -EFAULT;
+	if (nospc)
+		return -ENOSPC;
+	return 0;
+}
+
+void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
+				struct bpf_prog *old_prog)
+{
+	struct bpf_prog_array_item *item;
+
+	for (item = array->items; item->prog; item++)
+		if (item->prog == old_prog) {
+			WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
+			break;
+		}
+}
+
+/**
+ * bpf_prog_array_delete_safe_at() - Replaces the program at the given
+ *                                   index into the program array with
+ *                                   a dummy no-op program.
+ * @array: a bpf_prog_array
+ * @index: the index of the program to replace
+ *
+ * Skips over dummy programs, by not counting them, when calculating
+ * the position of the program to replace.
+ *
+ * Return:
+ * * 0		- Success
+ * * -EINVAL	- Invalid index value. Must be a non-negative integer.
+ * * -ENOENT	- Index out of range
+ */
+int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
+{
+	return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
+}
+
+/**
+ * bpf_prog_array_update_at() - Updates the program at the given index
+ *                              into the program array.
+ * @array: a bpf_prog_array
+ * @index: the index of the program to update
+ * @prog: the program to insert into the array
+ *
+ * Skips over dummy programs, by not counting them, when calculating
+ * the position of the program to update.
+ *
+ * Return:
+ * * 0		- Success
+ * * -EINVAL	- Invalid index value. Must be a non-negative integer.
+ * * -ENOENT	- Index out of range
+ */
+int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
+			     struct bpf_prog *prog)
+{
+	struct bpf_prog_array_item *item;
+
+	if (unlikely(index < 0))
+		return -EINVAL;
+
+	for (item = array->items; item->prog; item++) {
+		if (item->prog == &dummy_bpf_prog.prog)
+			continue;
+		if (!index) {
+			WRITE_ONCE(item->prog, prog);
+			return 0;
+		}
+		index--;
+	}
+	return -ENOENT;
+}
+
+int bpf_prog_array_copy(struct bpf_prog_array *old_array,
+			struct bpf_prog *exclude_prog,
+			struct bpf_prog *include_prog,
+			struct bpf_prog_array **new_array)
+{
+	int new_prog_cnt, carry_prog_cnt = 0;
+	struct bpf_prog_array_item *existing;
+	struct bpf_prog_array *array;
+	bool found_exclude = false;
+	int new_prog_idx = 0;
+
+	/* Figure out how many existing progs we need to carry over to
+	 * the new array.
+	 */
+	if (old_array) {
+		existing = old_array->items;
+		for (; existing->prog; existing++) {
+			if (existing->prog == exclude_prog) {
+				found_exclude = true;
+				continue;
+			}
+			if (existing->prog != &dummy_bpf_prog.prog)
+				carry_prog_cnt++;
+			if (existing->prog == include_prog)
+				return -EEXIST;
+		}
+	}
+
+	if (exclude_prog && !found_exclude)
+		return -ENOENT;
+
+	/* How many progs (not NULL) will be in the new array? */
+	new_prog_cnt = carry_prog_cnt;
+	if (include_prog)
+		new_prog_cnt += 1;
+
+	/* Do we have any prog (not NULL) in the new array? */
+	if (!new_prog_cnt) {
+		*new_array = NULL;
+		return 0;
+	}
+
+	/* +1 as the end of prog_array is marked with NULL */
+	array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
+	if (!array)
+		return -ENOMEM;
+
+	/* Fill in the new prog array */
+	if (carry_prog_cnt) {
+		existing = old_array->items;
+		for (; existing->prog; existing++)
+			if (existing->prog != exclude_prog &&
+			    existing->prog != &dummy_bpf_prog.prog) {
+				array->items[new_prog_idx++].prog =
+					existing->prog;
+			}
+	}
+	if (include_prog)
+		array->items[new_prog_idx++].prog = include_prog;
+	array->items[new_prog_idx].prog = NULL;
+	*new_array = array;
+	return 0;
+}
+
+int bpf_prog_array_copy_info(struct bpf_prog_array *array,
+			     u32 *prog_ids, u32 request_cnt,
+			     u32 *prog_cnt)
+{
+	u32 cnt = 0;
+
+	if (array)
+		cnt = bpf_prog_array_length(array);
+
+	*prog_cnt = cnt;
+
+	/* return early if user requested only program count or nothing to copy */
+	if (!request_cnt || !cnt)
+		return 0;
+
+	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
+	return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
+								     : 0;
+}
+
+void __bpf_free_used_maps(struct bpf_prog_aux *aux,
+			  struct bpf_map **used_maps, u32 len)
+{
+	struct bpf_map *map;
+	u32 i;
+
+	for (i = 0; i < len; i++) {
+		map = used_maps[i];
+		if (map->ops->map_poke_untrack)
+			map->ops->map_poke_untrack(map, aux);
+		bpf_map_put(map);
+	}
+}
+
+static void bpf_free_used_maps(struct bpf_prog_aux *aux)
+{
+	__bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
+	kfree(aux->used_maps);
+}
+
+static void bpf_prog_free_deferred(struct work_struct *work)
+{
+	struct bpf_prog_aux *aux;
+	int i;
+
+	aux = container_of(work, struct bpf_prog_aux, work);
+	bpf_free_used_maps(aux);
+	if (bpf_prog_is_dev_bound(aux))
+		bpf_prog_offload_destroy(aux->prog);
+#ifdef CONFIG_PERF_EVENTS
+	if (aux->prog->has_callchain_buf)
+		put_callchain_buffers();
+#endif
+	if (aux->dst_trampoline)
+		bpf_trampoline_put(aux->dst_trampoline);
+	for (i = 0; i < aux->func_cnt; i++) {
+		/* We can just unlink the subprog poke descriptor table as
+		 * it was originally linked to the main program and is also
+		 * released along with it.
+		 */
+		aux->func[i]->aux->poke_tab = NULL;
+		bpf_jit_free(aux->func[i]);
+	}
+	if (aux->func_cnt) {
+		kfree(aux->func);
+		bpf_prog_unlock_free(aux->prog);
+	} else {
+		bpf_jit_free(aux->prog);
+	}
+}
+
+/* Free internal BPF program */
+void bpf_prog_free(struct bpf_prog *fp)
+{
+	struct bpf_prog_aux *aux = fp->aux;
+
+	if (aux->dst_prog)
+		bpf_prog_put(aux->dst_prog);
+	INIT_WORK(&aux->work, bpf_prog_free_deferred);
+	schedule_work(&aux->work);
+}
+EXPORT_SYMBOL_GPL(bpf_prog_free);
+
+/* RNG for unpriviledged user space with separated state from prandom_u32(). */
+static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
+
+void bpf_user_rnd_init_once(void)
+{
+	prandom_init_once(&bpf_user_rnd_state);
+}
+
+BPF_CALL_0(bpf_user_rnd_u32)
+{
+	/* Should someone ever have the rather unwise idea to use some
+	 * of the registers passed into this function, then note that
+	 * this function is called from native eBPF and classic-to-eBPF
+	 * transformations. Register assignments from both sides are
+	 * different, f.e. classic always sets fn(ctx, A, X) here.
+	 */
+	struct rnd_state *state;
+	u32 res;
+
+	state = &get_cpu_var(bpf_user_rnd_state);
+	res = prandom_u32_state(state);
+	put_cpu_var(bpf_user_rnd_state);
+
+	return res;
+}
+
+BPF_CALL_0(bpf_get_raw_cpu_id)
+{
+	return raw_smp_processor_id();
+}
+
+/* Weak definitions of helper functions in case we don't have bpf syscall. */
+const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
+const struct bpf_func_proto bpf_map_update_elem_proto __weak;
+const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
+const struct bpf_func_proto bpf_map_push_elem_proto __weak;
+const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
+const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
+const struct bpf_func_proto bpf_spin_lock_proto __weak;
+const struct bpf_func_proto bpf_spin_unlock_proto __weak;
+const struct bpf_func_proto bpf_jiffies64_proto __weak;
+
+const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
+const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
+const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
+const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
+const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
+
+const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
+const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
+const struct bpf_func_proto bpf_get_current_comm_proto __weak;
+const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
+const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
+const struct bpf_func_proto bpf_get_local_storage_proto __weak;
+const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
+const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
+const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
+
+const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
+{
+	return NULL;
+}
+
+u64 __weak
+bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
+		 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
+{
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL_GPL(bpf_event_output);
+
+/* Always built-in helper functions. */
+const struct bpf_func_proto bpf_tail_call_proto = {
+	.func		= NULL,
+	.gpl_only	= false,
+	.ret_type	= RET_VOID,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_CONST_MAP_PTR,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+/* Stub for JITs that only support cBPF. eBPF programs are interpreted.
+ * It is encouraged to implement bpf_int_jit_compile() instead, so that
+ * eBPF and implicitly also cBPF can get JITed!
+ */
+struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
+{
+	return prog;
+}
+
+/* Stub for JITs that support eBPF. All cBPF code gets transformed into
+ * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
+ */
+void __weak bpf_jit_compile(struct bpf_prog *prog)
+{
+}
+
+bool __weak bpf_helper_changes_pkt_data(void *func)
+{
+	return false;
+}
+
+/* Return TRUE if the JIT backend wants verifier to enable sub-register usage
+ * analysis code and wants explicit zero extension inserted by verifier.
+ * Otherwise, return FALSE.
+ */
+bool __weak bpf_jit_needs_zext(void)
+{
+	return false;
+}
+
+/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
+ * skb_copy_bits(), so provide a weak definition of it for NET-less config.
+ */
+int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
+			 int len)
+{
+	return -EFAULT;
+}
+
+int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
+			      void *addr1, void *addr2)
+{
+	return -ENOTSUPP;
+}
+
+DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
+EXPORT_SYMBOL(bpf_stats_enabled_key);
+
+/* All definitions of tracepoints related to BPF. */
+#define CREATE_TRACE_POINTS
+#include <linux/bpf_trace.h>
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
+EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
new file mode 100644
index 000000000..c61a23b56
--- /dev/null
+++ b/kernel/bpf/cpumap.c
@@ -0,0 +1,768 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* bpf/cpumap.c
+ *
+ * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
+ */
+
+/* The 'cpumap' is primarily used as a backend map for XDP BPF helper
+ * call bpf_redirect_map() and XDP_REDIRECT action, like 'devmap'.
+ *
+ * Unlike devmap which redirects XDP frames out another NIC device,
+ * this map type redirects raw XDP frames to another CPU.  The remote
+ * CPU will do SKB-allocation and call the normal network stack.
+ *
+ * This is a scalability and isolation mechanism, that allow
+ * separating the early driver network XDP layer, from the rest of the
+ * netstack, and assigning dedicated CPUs for this stage.  This
+ * basically allows for 10G wirespeed pre-filtering via bpf.
+ */
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/ptr_ring.h>
+#include <net/xdp.h>
+
+#include <linux/sched.h>
+#include <linux/workqueue.h>
+#include <linux/kthread.h>
+#include <linux/capability.h>
+#include <trace/events/xdp.h>
+
+#include <linux/netdevice.h>   /* netif_receive_skb_core */
+#include <linux/etherdevice.h> /* eth_type_trans */
+
+/* General idea: XDP packets getting XDP redirected to another CPU,
+ * will maximum be stored/queued for one driver ->poll() call.  It is
+ * guaranteed that queueing the frame and the flush operation happen on
+ * same CPU.  Thus, cpu_map_flush operation can deduct via this_cpu_ptr()
+ * which queue in bpf_cpu_map_entry contains packets.
+ */
+
+#define CPU_MAP_BULK_SIZE 8  /* 8 == one cacheline on 64-bit archs */
+struct bpf_cpu_map_entry;
+struct bpf_cpu_map;
+
+struct xdp_bulk_queue {
+	void *q[CPU_MAP_BULK_SIZE];
+	struct list_head flush_node;
+	struct bpf_cpu_map_entry *obj;
+	unsigned int count;
+};
+
+/* Struct for every remote "destination" CPU in map */
+struct bpf_cpu_map_entry {
+	u32 cpu;    /* kthread CPU and map index */
+	int map_id; /* Back reference to map */
+
+	/* XDP can run multiple RX-ring queues, need __percpu enqueue store */
+	struct xdp_bulk_queue __percpu *bulkq;
+
+	struct bpf_cpu_map *cmap;
+
+	/* Queue with potential multi-producers, and single-consumer kthread */
+	struct ptr_ring *queue;
+	struct task_struct *kthread;
+
+	struct bpf_cpumap_val value;
+	struct bpf_prog *prog;
+
+	atomic_t refcnt; /* Control when this struct can be free'ed */
+	struct rcu_head rcu;
+
+	struct work_struct kthread_stop_wq;
+};
+
+struct bpf_cpu_map {
+	struct bpf_map map;
+	/* Below members specific for map type */
+	struct bpf_cpu_map_entry **cpu_map;
+};
+
+static DEFINE_PER_CPU(struct list_head, cpu_map_flush_list);
+
+static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
+{
+	u32 value_size = attr->value_size;
+	struct bpf_cpu_map *cmap;
+	int err = -ENOMEM;
+	u64 cost;
+	int ret;
+
+	if (!bpf_capable())
+		return ERR_PTR(-EPERM);
+
+	/* check sanity of attributes */
+	if (attr->max_entries == 0 || attr->key_size != 4 ||
+	    (value_size != offsetofend(struct bpf_cpumap_val, qsize) &&
+	     value_size != offsetofend(struct bpf_cpumap_val, bpf_prog.fd)) ||
+	    attr->map_flags & ~BPF_F_NUMA_NODE)
+		return ERR_PTR(-EINVAL);
+
+	cmap = kzalloc(sizeof(*cmap), GFP_USER);
+	if (!cmap)
+		return ERR_PTR(-ENOMEM);
+
+	bpf_map_init_from_attr(&cmap->map, attr);
+
+	/* Pre-limit array size based on NR_CPUS, not final CPU check */
+	if (cmap->map.max_entries > NR_CPUS) {
+		err = -E2BIG;
+		goto free_cmap;
+	}
+
+	/* make sure page count doesn't overflow */
+	cost = (u64) cmap->map.max_entries * sizeof(struct bpf_cpu_map_entry *);
+
+	/* Notice returns -EPERM on if map size is larger than memlock limit */
+	ret = bpf_map_charge_init(&cmap->map.memory, cost);
+	if (ret) {
+		err = ret;
+		goto free_cmap;
+	}
+
+	/* Alloc array for possible remote "destination" CPUs */
+	cmap->cpu_map = bpf_map_area_alloc(cmap->map.max_entries *
+					   sizeof(struct bpf_cpu_map_entry *),
+					   cmap->map.numa_node);
+	if (!cmap->cpu_map)
+		goto free_charge;
+
+	return &cmap->map;
+free_charge:
+	bpf_map_charge_finish(&cmap->map.memory);
+free_cmap:
+	kfree(cmap);
+	return ERR_PTR(err);
+}
+
+static void get_cpu_map_entry(struct bpf_cpu_map_entry *rcpu)
+{
+	atomic_inc(&rcpu->refcnt);
+}
+
+/* called from workqueue, to workaround syscall using preempt_disable */
+static void cpu_map_kthread_stop(struct work_struct *work)
+{
+	struct bpf_cpu_map_entry *rcpu;
+
+	rcpu = container_of(work, struct bpf_cpu_map_entry, kthread_stop_wq);
+
+	/* Wait for flush in __cpu_map_entry_free(), via full RCU barrier,
+	 * as it waits until all in-flight call_rcu() callbacks complete.
+	 */
+	rcu_barrier();
+
+	/* kthread_stop will wake_up_process and wait for it to complete */
+	kthread_stop(rcpu->kthread);
+}
+
+static struct sk_buff *cpu_map_build_skb(struct xdp_frame *xdpf,
+					 struct sk_buff *skb)
+{
+	unsigned int hard_start_headroom;
+	unsigned int frame_size;
+	void *pkt_data_start;
+
+	/* Part of headroom was reserved to xdpf */
+	hard_start_headroom = sizeof(struct xdp_frame) +  xdpf->headroom;
+
+	/* Memory size backing xdp_frame data already have reserved
+	 * room for build_skb to place skb_shared_info in tailroom.
+	 */
+	frame_size = xdpf->frame_sz;
+
+	pkt_data_start = xdpf->data - hard_start_headroom;
+	skb = build_skb_around(skb, pkt_data_start, frame_size);
+	if (unlikely(!skb))
+		return NULL;
+
+	skb_reserve(skb, hard_start_headroom);
+	__skb_put(skb, xdpf->len);
+	if (xdpf->metasize)
+		skb_metadata_set(skb, xdpf->metasize);
+
+	/* Essential SKB info: protocol and skb->dev */
+	skb->protocol = eth_type_trans(skb, xdpf->dev_rx);
+
+	/* Optional SKB info, currently missing:
+	 * - HW checksum info		(skb->ip_summed)
+	 * - HW RX hash			(skb_set_hash)
+	 * - RX ring dev queue index	(skb_record_rx_queue)
+	 */
+
+	/* Until page_pool get SKB return path, release DMA here */
+	xdp_release_frame(xdpf);
+
+	/* Allow SKB to reuse area used by xdp_frame */
+	xdp_scrub_frame(xdpf);
+
+	return skb;
+}
+
+static void __cpu_map_ring_cleanup(struct ptr_ring *ring)
+{
+	/* The tear-down procedure should have made sure that queue is
+	 * empty.  See __cpu_map_entry_replace() and work-queue
+	 * invoked cpu_map_kthread_stop(). Catch any broken behaviour
+	 * gracefully and warn once.
+	 */
+	struct xdp_frame *xdpf;
+
+	while ((xdpf = ptr_ring_consume(ring)))
+		if (WARN_ON_ONCE(xdpf))
+			xdp_return_frame(xdpf);
+}
+
+static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu)
+{
+	if (atomic_dec_and_test(&rcpu->refcnt)) {
+		if (rcpu->prog)
+			bpf_prog_put(rcpu->prog);
+		/* The queue should be empty at this point */
+		__cpu_map_ring_cleanup(rcpu->queue);
+		ptr_ring_cleanup(rcpu->queue, NULL);
+		kfree(rcpu->queue);
+		kfree(rcpu);
+	}
+}
+
+static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu,
+				    void **frames, int n,
+				    struct xdp_cpumap_stats *stats)
+{
+	struct xdp_rxq_info rxq;
+	struct xdp_buff xdp;
+	int i, nframes = 0;
+
+	if (!rcpu->prog)
+		return n;
+
+	rcu_read_lock_bh();
+
+	xdp_set_return_frame_no_direct();
+	xdp.rxq = &rxq;
+
+	for (i = 0; i < n; i++) {
+		struct xdp_frame *xdpf = frames[i];
+		u32 act;
+		int err;
+
+		rxq.dev = xdpf->dev_rx;
+		rxq.mem = xdpf->mem;
+		/* TODO: report queue_index to xdp_rxq_info */
+
+		xdp_convert_frame_to_buff(xdpf, &xdp);
+
+		act = bpf_prog_run_xdp(rcpu->prog, &xdp);
+		switch (act) {
+		case XDP_PASS:
+			err = xdp_update_frame_from_buff(&xdp, xdpf);
+			if (err < 0) {
+				xdp_return_frame(xdpf);
+				stats->drop++;
+			} else {
+				frames[nframes++] = xdpf;
+				stats->pass++;
+			}
+			break;
+		case XDP_REDIRECT:
+			err = xdp_do_redirect(xdpf->dev_rx, &xdp,
+					      rcpu->prog);
+			if (unlikely(err)) {
+				xdp_return_frame(xdpf);
+				stats->drop++;
+			} else {
+				stats->redirect++;
+			}
+			break;
+		default:
+			bpf_warn_invalid_xdp_action(act);
+			fallthrough;
+		case XDP_DROP:
+			xdp_return_frame(xdpf);
+			stats->drop++;
+			break;
+		}
+	}
+
+	if (stats->redirect)
+		xdp_do_flush_map();
+
+	xdp_clear_return_frame_no_direct();
+
+	rcu_read_unlock_bh(); /* resched point, may call do_softirq() */
+
+	return nframes;
+}
+
+#define CPUMAP_BATCH 8
+
+static int cpu_map_kthread_run(void *data)
+{
+	struct bpf_cpu_map_entry *rcpu = data;
+
+	set_current_state(TASK_INTERRUPTIBLE);
+
+	/* When kthread gives stop order, then rcpu have been disconnected
+	 * from map, thus no new packets can enter. Remaining in-flight
+	 * per CPU stored packets are flushed to this queue.  Wait honoring
+	 * kthread_stop signal until queue is empty.
+	 */
+	while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) {
+		struct xdp_cpumap_stats stats = {}; /* zero stats */
+		gfp_t gfp = __GFP_ZERO | GFP_ATOMIC;
+		unsigned int drops = 0, sched = 0;
+		void *frames[CPUMAP_BATCH];
+		void *skbs[CPUMAP_BATCH];
+		int i, n, m, nframes;
+
+		/* Release CPU reschedule checks */
+		if (__ptr_ring_empty(rcpu->queue)) {
+			set_current_state(TASK_INTERRUPTIBLE);
+			/* Recheck to avoid lost wake-up */
+			if (__ptr_ring_empty(rcpu->queue)) {
+				schedule();
+				sched = 1;
+			} else {
+				__set_current_state(TASK_RUNNING);
+			}
+		} else {
+			sched = cond_resched();
+		}
+
+		/*
+		 * The bpf_cpu_map_entry is single consumer, with this
+		 * kthread CPU pinned. Lockless access to ptr_ring
+		 * consume side valid as no-resize allowed of queue.
+		 */
+		n = __ptr_ring_consume_batched(rcpu->queue, frames,
+					       CPUMAP_BATCH);
+		for (i = 0; i < n; i++) {
+			void *f = frames[i];
+			struct page *page = virt_to_page(f);
+
+			/* Bring struct page memory area to curr CPU. Read by
+			 * build_skb_around via page_is_pfmemalloc(), and when
+			 * freed written by page_frag_free call.
+			 */
+			prefetchw(page);
+		}
+
+		/* Support running another XDP prog on this CPU */
+		nframes = cpu_map_bpf_prog_run_xdp(rcpu, frames, n, &stats);
+		if (nframes) {
+			m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, nframes, skbs);
+			if (unlikely(m == 0)) {
+				for (i = 0; i < nframes; i++)
+					skbs[i] = NULL; /* effect: xdp_return_frame */
+				drops += nframes;
+			}
+		}
+
+		local_bh_disable();
+		for (i = 0; i < nframes; i++) {
+			struct xdp_frame *xdpf = frames[i];
+			struct sk_buff *skb = skbs[i];
+			int ret;
+
+			skb = cpu_map_build_skb(xdpf, skb);
+			if (!skb) {
+				xdp_return_frame(xdpf);
+				continue;
+			}
+
+			/* Inject into network stack */
+			ret = netif_receive_skb_core(skb);
+			if (ret == NET_RX_DROP)
+				drops++;
+		}
+		/* Feedback loop via tracepoint */
+		trace_xdp_cpumap_kthread(rcpu->map_id, n, drops, sched, &stats);
+
+		local_bh_enable(); /* resched point, may call do_softirq() */
+	}
+	__set_current_state(TASK_RUNNING);
+
+	put_cpu_map_entry(rcpu);
+	return 0;
+}
+
+bool cpu_map_prog_allowed(struct bpf_map *map)
+{
+	return map->map_type == BPF_MAP_TYPE_CPUMAP &&
+	       map->value_size != offsetofend(struct bpf_cpumap_val, qsize);
+}
+
+static int __cpu_map_load_bpf_program(struct bpf_cpu_map_entry *rcpu, int fd)
+{
+	struct bpf_prog *prog;
+
+	prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_XDP);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	if (prog->expected_attach_type != BPF_XDP_CPUMAP) {
+		bpf_prog_put(prog);
+		return -EINVAL;
+	}
+
+	rcpu->value.bpf_prog.id = prog->aux->id;
+	rcpu->prog = prog;
+
+	return 0;
+}
+
+static struct bpf_cpu_map_entry *
+__cpu_map_entry_alloc(struct bpf_cpumap_val *value, u32 cpu, int map_id)
+{
+	int numa, err, i, fd = value->bpf_prog.fd;
+	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
+	struct bpf_cpu_map_entry *rcpu;
+	struct xdp_bulk_queue *bq;
+
+	/* Have map->numa_node, but choose node of redirect target CPU */
+	numa = cpu_to_node(cpu);
+
+	rcpu = kzalloc_node(sizeof(*rcpu), gfp, numa);
+	if (!rcpu)
+		return NULL;
+
+	/* Alloc percpu bulkq */
+	rcpu->bulkq = __alloc_percpu_gfp(sizeof(*rcpu->bulkq),
+					 sizeof(void *), gfp);
+	if (!rcpu->bulkq)
+		goto free_rcu;
+
+	for_each_possible_cpu(i) {
+		bq = per_cpu_ptr(rcpu->bulkq, i);
+		bq->obj = rcpu;
+	}
+
+	/* Alloc queue */
+	rcpu->queue = kzalloc_node(sizeof(*rcpu->queue), gfp, numa);
+	if (!rcpu->queue)
+		goto free_bulkq;
+
+	err = ptr_ring_init(rcpu->queue, value->qsize, gfp);
+	if (err)
+		goto free_queue;
+
+	rcpu->cpu    = cpu;
+	rcpu->map_id = map_id;
+	rcpu->value.qsize  = value->qsize;
+
+	if (fd > 0 && __cpu_map_load_bpf_program(rcpu, fd))
+		goto free_ptr_ring;
+
+	/* Setup kthread */
+	rcpu->kthread = kthread_create_on_node(cpu_map_kthread_run, rcpu, numa,
+					       "cpumap/%d/map:%d", cpu, map_id);
+	if (IS_ERR(rcpu->kthread))
+		goto free_prog;
+
+	get_cpu_map_entry(rcpu); /* 1-refcnt for being in cmap->cpu_map[] */
+	get_cpu_map_entry(rcpu); /* 1-refcnt for kthread */
+
+	/* Make sure kthread runs on a single CPU */
+	kthread_bind(rcpu->kthread, cpu);
+	wake_up_process(rcpu->kthread);
+
+	return rcpu;
+
+free_prog:
+	if (rcpu->prog)
+		bpf_prog_put(rcpu->prog);
+free_ptr_ring:
+	ptr_ring_cleanup(rcpu->queue, NULL);
+free_queue:
+	kfree(rcpu->queue);
+free_bulkq:
+	free_percpu(rcpu->bulkq);
+free_rcu:
+	kfree(rcpu);
+	return NULL;
+}
+
+static void __cpu_map_entry_free(struct rcu_head *rcu)
+{
+	struct bpf_cpu_map_entry *rcpu;
+
+	/* This cpu_map_entry have been disconnected from map and one
+	 * RCU grace-period have elapsed.  Thus, XDP cannot queue any
+	 * new packets and cannot change/set flush_needed that can
+	 * find this entry.
+	 */
+	rcpu = container_of(rcu, struct bpf_cpu_map_entry, rcu);
+
+	free_percpu(rcpu->bulkq);
+	/* Cannot kthread_stop() here, last put free rcpu resources */
+	put_cpu_map_entry(rcpu);
+}
+
+/* After xchg pointer to bpf_cpu_map_entry, use the call_rcu() to
+ * ensure any driver rcu critical sections have completed, but this
+ * does not guarantee a flush has happened yet. Because driver side
+ * rcu_read_lock/unlock only protects the running XDP program.  The
+ * atomic xchg and NULL-ptr check in __cpu_map_flush() makes sure a
+ * pending flush op doesn't fail.
+ *
+ * The bpf_cpu_map_entry is still used by the kthread, and there can
+ * still be pending packets (in queue and percpu bulkq).  A refcnt
+ * makes sure to last user (kthread_stop vs. call_rcu) free memory
+ * resources.
+ *
+ * The rcu callback __cpu_map_entry_free flush remaining packets in
+ * percpu bulkq to queue.  Due to caller map_delete_elem() disable
+ * preemption, cannot call kthread_stop() to make sure queue is empty.
+ * Instead a work_queue is started for stopping kthread,
+ * cpu_map_kthread_stop, which waits for an RCU grace period before
+ * stopping kthread, emptying the queue.
+ */
+static void __cpu_map_entry_replace(struct bpf_cpu_map *cmap,
+				    u32 key_cpu, struct bpf_cpu_map_entry *rcpu)
+{
+	struct bpf_cpu_map_entry *old_rcpu;
+
+	old_rcpu = xchg(&cmap->cpu_map[key_cpu], rcpu);
+	if (old_rcpu) {
+		call_rcu(&old_rcpu->rcu, __cpu_map_entry_free);
+		INIT_WORK(&old_rcpu->kthread_stop_wq, cpu_map_kthread_stop);
+		schedule_work(&old_rcpu->kthread_stop_wq);
+	}
+}
+
+static int cpu_map_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
+	u32 key_cpu = *(u32 *)key;
+
+	if (key_cpu >= map->max_entries)
+		return -EINVAL;
+
+	/* notice caller map_delete_elem() use preempt_disable() */
+	__cpu_map_entry_replace(cmap, key_cpu, NULL);
+	return 0;
+}
+
+static int cpu_map_update_elem(struct bpf_map *map, void *key, void *value,
+			       u64 map_flags)
+{
+	struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
+	struct bpf_cpumap_val cpumap_value = {};
+	struct bpf_cpu_map_entry *rcpu;
+	/* Array index key correspond to CPU number */
+	u32 key_cpu = *(u32 *)key;
+
+	memcpy(&cpumap_value, value, map->value_size);
+
+	if (unlikely(map_flags > BPF_EXIST))
+		return -EINVAL;
+	if (unlikely(key_cpu >= cmap->map.max_entries))
+		return -E2BIG;
+	if (unlikely(map_flags == BPF_NOEXIST))
+		return -EEXIST;
+	if (unlikely(cpumap_value.qsize > 16384)) /* sanity limit on qsize */
+		return -EOVERFLOW;
+
+	/* Make sure CPU is a valid possible cpu */
+	if (key_cpu >= nr_cpumask_bits || !cpu_possible(key_cpu))
+		return -ENODEV;
+
+	if (cpumap_value.qsize == 0) {
+		rcpu = NULL; /* Same as deleting */
+	} else {
+		/* Updating qsize cause re-allocation of bpf_cpu_map_entry */
+		rcpu = __cpu_map_entry_alloc(&cpumap_value, key_cpu, map->id);
+		if (!rcpu)
+			return -ENOMEM;
+		rcpu->cmap = cmap;
+	}
+	rcu_read_lock();
+	__cpu_map_entry_replace(cmap, key_cpu, rcpu);
+	rcu_read_unlock();
+	return 0;
+}
+
+static void cpu_map_free(struct bpf_map *map)
+{
+	struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
+	u32 i;
+
+	/* At this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
+	 * so the bpf programs (can be more than one that used this map) were
+	 * disconnected from events. Wait for outstanding critical sections in
+	 * these programs to complete. The rcu critical section only guarantees
+	 * no further "XDP/bpf-side" reads against bpf_cpu_map->cpu_map.
+	 * It does __not__ ensure pending flush operations (if any) are
+	 * complete.
+	 */
+
+	bpf_clear_redirect_map(map);
+	synchronize_rcu();
+
+	/* For cpu_map the remote CPUs can still be using the entries
+	 * (struct bpf_cpu_map_entry).
+	 */
+	for (i = 0; i < cmap->map.max_entries; i++) {
+		struct bpf_cpu_map_entry *rcpu;
+
+		rcpu = READ_ONCE(cmap->cpu_map[i]);
+		if (!rcpu)
+			continue;
+
+		/* bq flush and cleanup happens after RCU grace-period */
+		__cpu_map_entry_replace(cmap, i, NULL); /* call_rcu */
+	}
+	bpf_map_area_free(cmap->cpu_map);
+	kfree(cmap);
+}
+
+struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key)
+{
+	struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
+	struct bpf_cpu_map_entry *rcpu;
+
+	if (key >= map->max_entries)
+		return NULL;
+
+	rcpu = READ_ONCE(cmap->cpu_map[key]);
+	return rcpu;
+}
+
+static void *cpu_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_cpu_map_entry *rcpu =
+		__cpu_map_lookup_elem(map, *(u32 *)key);
+
+	return rcpu ? &rcpu->value : NULL;
+}
+
+static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+	struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
+	u32 index = key ? *(u32 *)key : U32_MAX;
+	u32 *next = next_key;
+
+	if (index >= cmap->map.max_entries) {
+		*next = 0;
+		return 0;
+	}
+
+	if (index == cmap->map.max_entries - 1)
+		return -ENOENT;
+	*next = index + 1;
+	return 0;
+}
+
+static int cpu_map_btf_id;
+const struct bpf_map_ops cpu_map_ops = {
+	.map_meta_equal		= bpf_map_meta_equal,
+	.map_alloc		= cpu_map_alloc,
+	.map_free		= cpu_map_free,
+	.map_delete_elem	= cpu_map_delete_elem,
+	.map_update_elem	= cpu_map_update_elem,
+	.map_lookup_elem	= cpu_map_lookup_elem,
+	.map_get_next_key	= cpu_map_get_next_key,
+	.map_check_btf		= map_check_no_btf,
+	.map_btf_name		= "bpf_cpu_map",
+	.map_btf_id		= &cpu_map_btf_id,
+};
+
+static void bq_flush_to_queue(struct xdp_bulk_queue *bq)
+{
+	struct bpf_cpu_map_entry *rcpu = bq->obj;
+	unsigned int processed = 0, drops = 0;
+	const int to_cpu = rcpu->cpu;
+	struct ptr_ring *q;
+	int i;
+
+	if (unlikely(!bq->count))
+		return;
+
+	q = rcpu->queue;
+	spin_lock(&q->producer_lock);
+
+	for (i = 0; i < bq->count; i++) {
+		struct xdp_frame *xdpf = bq->q[i];
+		int err;
+
+		err = __ptr_ring_produce(q, xdpf);
+		if (err) {
+			drops++;
+			xdp_return_frame_rx_napi(xdpf);
+		}
+		processed++;
+	}
+	bq->count = 0;
+	spin_unlock(&q->producer_lock);
+
+	__list_del_clearprev(&bq->flush_node);
+
+	/* Feedback loop via tracepoints */
+	trace_xdp_cpumap_enqueue(rcpu->map_id, processed, drops, to_cpu);
+}
+
+/* Runs under RCU-read-side, plus in softirq under NAPI protection.
+ * Thus, safe percpu variable access.
+ */
+static void bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf)
+{
+	struct list_head *flush_list = this_cpu_ptr(&cpu_map_flush_list);
+	struct xdp_bulk_queue *bq = this_cpu_ptr(rcpu->bulkq);
+
+	if (unlikely(bq->count == CPU_MAP_BULK_SIZE))
+		bq_flush_to_queue(bq);
+
+	/* Notice, xdp_buff/page MUST be queued here, long enough for
+	 * driver to code invoking us to finished, due to driver
+	 * (e.g. ixgbe) recycle tricks based on page-refcnt.
+	 *
+	 * Thus, incoming xdp_frame is always queued here (else we race
+	 * with another CPU on page-refcnt and remaining driver code).
+	 * Queue time is very short, as driver will invoke flush
+	 * operation, when completing napi->poll call.
+	 */
+	bq->q[bq->count++] = xdpf;
+
+	if (!bq->flush_node.prev)
+		list_add(&bq->flush_node, flush_list);
+}
+
+int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp,
+		    struct net_device *dev_rx)
+{
+	struct xdp_frame *xdpf;
+
+	xdpf = xdp_convert_buff_to_frame(xdp);
+	if (unlikely(!xdpf))
+		return -EOVERFLOW;
+
+	/* Info needed when constructing SKB on remote CPU */
+	xdpf->dev_rx = dev_rx;
+
+	bq_enqueue(rcpu, xdpf);
+	return 0;
+}
+
+void __cpu_map_flush(void)
+{
+	struct list_head *flush_list = this_cpu_ptr(&cpu_map_flush_list);
+	struct xdp_bulk_queue *bq, *tmp;
+
+	list_for_each_entry_safe(bq, tmp, flush_list, flush_node) {
+		bq_flush_to_queue(bq);
+
+		/* If already running, costs spin_lock_irqsave + smb_mb */
+		wake_up_process(bq->obj->kthread);
+	}
+}
+
+static int __init cpu_map_init(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		INIT_LIST_HEAD(&per_cpu(cpu_map_flush_list, cpu));
+	return 0;
+}
+
+subsys_initcall(cpu_map_init);
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
new file mode 100644
index 000000000..01149821d
--- /dev/null
+++ b/kernel/bpf/devmap.c
@@ -0,0 +1,876 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
+ */
+
+/* Devmaps primary use is as a backend map for XDP BPF helper call
+ * bpf_redirect_map(). Because XDP is mostly concerned with performance we
+ * spent some effort to ensure the datapath with redirect maps does not use
+ * any locking. This is a quick note on the details.
+ *
+ * We have three possible paths to get into the devmap control plane bpf
+ * syscalls, bpf programs, and driver side xmit/flush operations. A bpf syscall
+ * will invoke an update, delete, or lookup operation. To ensure updates and
+ * deletes appear atomic from the datapath side xchg() is used to modify the
+ * netdev_map array. Then because the datapath does a lookup into the netdev_map
+ * array (read-only) from an RCU critical section we use call_rcu() to wait for
+ * an rcu grace period before free'ing the old data structures. This ensures the
+ * datapath always has a valid copy. However, the datapath does a "flush"
+ * operation that pushes any pending packets in the driver outside the RCU
+ * critical section. Each bpf_dtab_netdev tracks these pending operations using
+ * a per-cpu flush list. The bpf_dtab_netdev object will not be destroyed  until
+ * this list is empty, indicating outstanding flush operations have completed.
+ *
+ * BPF syscalls may race with BPF program calls on any of the update, delete
+ * or lookup operations. As noted above the xchg() operation also keep the
+ * netdev_map consistent in this case. From the devmap side BPF programs
+ * calling into these operations are the same as multiple user space threads
+ * making system calls.
+ *
+ * Finally, any of the above may race with a netdev_unregister notifier. The
+ * unregister notifier must search for net devices in the map structure that
+ * contain a reference to the net device and remove them. This is a two step
+ * process (a) dereference the bpf_dtab_netdev object in netdev_map and (b)
+ * check to see if the ifindex is the same as the net_device being removed.
+ * When removing the dev a cmpxchg() is used to ensure the correct dev is
+ * removed, in the case of a concurrent update or delete operation it is
+ * possible that the initially referenced dev is no longer in the map. As the
+ * notifier hook walks the map we know that new dev references can not be
+ * added by the user because core infrastructure ensures dev_get_by_index()
+ * calls will fail at this point.
+ *
+ * The devmap_hash type is a map type which interprets keys as ifindexes and
+ * indexes these using a hashmap. This allows maps that use ifindex as key to be
+ * densely packed instead of having holes in the lookup array for unused
+ * ifindexes. The setup and packet enqueue/send code is shared between the two
+ * types of devmap; only the lookup and insertion is different.
+ */
+#include <linux/bpf.h>
+#include <net/xdp.h>
+#include <linux/filter.h>
+#include <trace/events/xdp.h>
+
+#define DEV_CREATE_FLAG_MASK \
+	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+
+struct xdp_dev_bulk_queue {
+	struct xdp_frame *q[DEV_MAP_BULK_SIZE];
+	struct list_head flush_node;
+	struct net_device *dev;
+	struct net_device *dev_rx;
+	unsigned int count;
+};
+
+struct bpf_dtab_netdev {
+	struct net_device *dev; /* must be first member, due to tracepoint */
+	struct hlist_node index_hlist;
+	struct bpf_dtab *dtab;
+	struct bpf_prog *xdp_prog;
+	struct rcu_head rcu;
+	unsigned int idx;
+	struct bpf_devmap_val val;
+};
+
+struct bpf_dtab {
+	struct bpf_map map;
+	struct bpf_dtab_netdev **netdev_map; /* DEVMAP type only */
+	struct list_head list;
+
+	/* these are only used for DEVMAP_HASH type maps */
+	struct hlist_head *dev_index_head;
+	spinlock_t index_lock;
+	unsigned int items;
+	u32 n_buckets;
+};
+
+static DEFINE_PER_CPU(struct list_head, dev_flush_list);
+static DEFINE_SPINLOCK(dev_map_lock);
+static LIST_HEAD(dev_map_list);
+
+static struct hlist_head *dev_map_create_hash(unsigned int entries,
+					      int numa_node)
+{
+	int i;
+	struct hlist_head *hash;
+
+	hash = bpf_map_area_alloc((u64) entries * sizeof(*hash), numa_node);
+	if (hash != NULL)
+		for (i = 0; i < entries; i++)
+			INIT_HLIST_HEAD(&hash[i]);
+
+	return hash;
+}
+
+static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab,
+						    int idx)
+{
+	return &dtab->dev_index_head[idx & (dtab->n_buckets - 1)];
+}
+
+static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
+{
+	u32 valsize = attr->value_size;
+	u64 cost = 0;
+	int err;
+
+	/* check sanity of attributes. 2 value sizes supported:
+	 * 4 bytes: ifindex
+	 * 8 bytes: ifindex + prog fd
+	 */
+	if (attr->max_entries == 0 || attr->key_size != 4 ||
+	    (valsize != offsetofend(struct bpf_devmap_val, ifindex) &&
+	     valsize != offsetofend(struct bpf_devmap_val, bpf_prog.fd)) ||
+	    attr->map_flags & ~DEV_CREATE_FLAG_MASK)
+		return -EINVAL;
+
+	/* Lookup returns a pointer straight to dev->ifindex, so make sure the
+	 * verifier prevents writes from the BPF side
+	 */
+	attr->map_flags |= BPF_F_RDONLY_PROG;
+
+
+	bpf_map_init_from_attr(&dtab->map, attr);
+
+	if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+		dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
+
+		if (!dtab->n_buckets) /* Overflow check */
+			return -EINVAL;
+		cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets;
+	} else {
+		cost += (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
+	}
+
+	/* if map size is larger than memlock limit, reject it */
+	err = bpf_map_charge_init(&dtab->map.memory, cost);
+	if (err)
+		return -EINVAL;
+
+	if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+		dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets,
+							   dtab->map.numa_node);
+		if (!dtab->dev_index_head)
+			goto free_charge;
+
+		spin_lock_init(&dtab->index_lock);
+	} else {
+		dtab->netdev_map = bpf_map_area_alloc((u64) dtab->map.max_entries *
+						      sizeof(struct bpf_dtab_netdev *),
+						      dtab->map.numa_node);
+		if (!dtab->netdev_map)
+			goto free_charge;
+	}
+
+	return 0;
+
+free_charge:
+	bpf_map_charge_finish(&dtab->map.memory);
+	return -ENOMEM;
+}
+
+static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_dtab *dtab;
+	int err;
+
+	if (!capable(CAP_NET_ADMIN))
+		return ERR_PTR(-EPERM);
+
+	dtab = kzalloc(sizeof(*dtab), GFP_USER);
+	if (!dtab)
+		return ERR_PTR(-ENOMEM);
+
+	err = dev_map_init_map(dtab, attr);
+	if (err) {
+		kfree(dtab);
+		return ERR_PTR(err);
+	}
+
+	spin_lock(&dev_map_lock);
+	list_add_tail_rcu(&dtab->list, &dev_map_list);
+	spin_unlock(&dev_map_lock);
+
+	return &dtab->map;
+}
+
+static void dev_map_free(struct bpf_map *map)
+{
+	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+	int i;
+
+	/* At this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
+	 * so the programs (can be more than one that used this map) were
+	 * disconnected from events. The following synchronize_rcu() guarantees
+	 * both rcu read critical sections complete and waits for
+	 * preempt-disable regions (NAPI being the relevant context here) so we
+	 * are certain there will be no further reads against the netdev_map and
+	 * all flush operations are complete. Flush operations can only be done
+	 * from NAPI context for this reason.
+	 */
+
+	spin_lock(&dev_map_lock);
+	list_del_rcu(&dtab->list);
+	spin_unlock(&dev_map_lock);
+
+	bpf_clear_redirect_map(map);
+	synchronize_rcu();
+
+	/* Make sure prior __dev_map_entry_free() have completed. */
+	rcu_barrier();
+
+	if (dtab->map.map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+		for (i = 0; i < dtab->n_buckets; i++) {
+			struct bpf_dtab_netdev *dev;
+			struct hlist_head *head;
+			struct hlist_node *next;
+
+			head = dev_map_index_hash(dtab, i);
+
+			hlist_for_each_entry_safe(dev, next, head, index_hlist) {
+				hlist_del_rcu(&dev->index_hlist);
+				if (dev->xdp_prog)
+					bpf_prog_put(dev->xdp_prog);
+				dev_put(dev->dev);
+				kfree(dev);
+			}
+		}
+
+		bpf_map_area_free(dtab->dev_index_head);
+	} else {
+		for (i = 0; i < dtab->map.max_entries; i++) {
+			struct bpf_dtab_netdev *dev;
+
+			dev = dtab->netdev_map[i];
+			if (!dev)
+				continue;
+
+			if (dev->xdp_prog)
+				bpf_prog_put(dev->xdp_prog);
+			dev_put(dev->dev);
+			kfree(dev);
+		}
+
+		bpf_map_area_free(dtab->netdev_map);
+	}
+
+	kfree(dtab);
+}
+
+static int dev_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+	u32 index = key ? *(u32 *)key : U32_MAX;
+	u32 *next = next_key;
+
+	if (index >= dtab->map.max_entries) {
+		*next = 0;
+		return 0;
+	}
+
+	if (index == dtab->map.max_entries - 1)
+		return -ENOENT;
+	*next = index + 1;
+	return 0;
+}
+
+struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
+{
+	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+	struct hlist_head *head = dev_map_index_hash(dtab, key);
+	struct bpf_dtab_netdev *dev;
+
+	hlist_for_each_entry_rcu(dev, head, index_hlist,
+				 lockdep_is_held(&dtab->index_lock))
+		if (dev->idx == key)
+			return dev;
+
+	return NULL;
+}
+
+static int dev_map_hash_get_next_key(struct bpf_map *map, void *key,
+				    void *next_key)
+{
+	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+	u32 idx, *next = next_key;
+	struct bpf_dtab_netdev *dev, *next_dev;
+	struct hlist_head *head;
+	int i = 0;
+
+	if (!key)
+		goto find_first;
+
+	idx = *(u32 *)key;
+
+	dev = __dev_map_hash_lookup_elem(map, idx);
+	if (!dev)
+		goto find_first;
+
+	next_dev = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&dev->index_hlist)),
+				    struct bpf_dtab_netdev, index_hlist);
+
+	if (next_dev) {
+		*next = next_dev->idx;
+		return 0;
+	}
+
+	i = idx & (dtab->n_buckets - 1);
+	i++;
+
+ find_first:
+	for (; i < dtab->n_buckets; i++) {
+		head = dev_map_index_hash(dtab, i);
+
+		next_dev = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),
+					    struct bpf_dtab_netdev,
+					    index_hlist);
+		if (next_dev) {
+			*next = next_dev->idx;
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+bool dev_map_can_have_prog(struct bpf_map *map)
+{
+	if ((map->map_type == BPF_MAP_TYPE_DEVMAP ||
+	     map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) &&
+	    map->value_size != offsetofend(struct bpf_devmap_val, ifindex))
+		return true;
+
+	return false;
+}
+
+static void bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags)
+{
+	struct net_device *dev = bq->dev;
+	int sent = 0, drops = 0, err = 0;
+	int i;
+
+	if (unlikely(!bq->count))
+		return;
+
+	for (i = 0; i < bq->count; i++) {
+		struct xdp_frame *xdpf = bq->q[i];
+
+		prefetch(xdpf);
+	}
+
+	sent = dev->netdev_ops->ndo_xdp_xmit(dev, bq->count, bq->q, flags);
+	if (sent < 0) {
+		err = sent;
+		sent = 0;
+		goto error;
+	}
+	drops = bq->count - sent;
+out:
+	bq->count = 0;
+
+	trace_xdp_devmap_xmit(bq->dev_rx, dev, sent, drops, err);
+	bq->dev_rx = NULL;
+	__list_del_clearprev(&bq->flush_node);
+	return;
+error:
+	/* If ndo_xdp_xmit fails with an errno, no frames have been
+	 * xmit'ed and it's our responsibility to them free all.
+	 */
+	for (i = 0; i < bq->count; i++) {
+		struct xdp_frame *xdpf = bq->q[i];
+
+		xdp_return_frame_rx_napi(xdpf);
+		drops++;
+	}
+	goto out;
+}
+
+/* __dev_flush is called from xdp_do_flush() which _must_ be signaled
+ * from the driver before returning from its napi->poll() routine. The poll()
+ * routine is called either from busy_poll context or net_rx_action signaled
+ * from NET_RX_SOFTIRQ. Either way the poll routine must complete before the
+ * net device can be torn down. On devmap tear down we ensure the flush list
+ * is empty before completing to ensure all flush operations have completed.
+ * When drivers update the bpf program they may need to ensure any flush ops
+ * are also complete. Using synchronize_rcu or call_rcu will suffice for this
+ * because both wait for napi context to exit.
+ */
+void __dev_flush(void)
+{
+	struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
+	struct xdp_dev_bulk_queue *bq, *tmp;
+
+	list_for_each_entry_safe(bq, tmp, flush_list, flush_node)
+		bq_xmit_all(bq, XDP_XMIT_FLUSH);
+}
+
+/* rcu_read_lock (from syscall and BPF contexts) ensures that if a delete and/or
+ * update happens in parallel here a dev_put wont happen until after reading the
+ * ifindex.
+ */
+struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
+{
+	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+	struct bpf_dtab_netdev *obj;
+
+	if (key >= map->max_entries)
+		return NULL;
+
+	obj = READ_ONCE(dtab->netdev_map[key]);
+	return obj;
+}
+
+/* Runs under RCU-read-side, plus in softirq under NAPI protection.
+ * Thus, safe percpu variable access.
+ */
+static void bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf,
+		       struct net_device *dev_rx)
+{
+	struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
+	struct xdp_dev_bulk_queue *bq = this_cpu_ptr(dev->xdp_bulkq);
+
+	if (unlikely(bq->count == DEV_MAP_BULK_SIZE))
+		bq_xmit_all(bq, 0);
+
+	/* Ingress dev_rx will be the same for all xdp_frame's in
+	 * bulk_queue, because bq stored per-CPU and must be flushed
+	 * from net_device drivers NAPI func end.
+	 */
+	if (!bq->dev_rx)
+		bq->dev_rx = dev_rx;
+
+	bq->q[bq->count++] = xdpf;
+
+	if (!bq->flush_node.prev)
+		list_add(&bq->flush_node, flush_list);
+}
+
+static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
+			       struct net_device *dev_rx)
+{
+	struct xdp_frame *xdpf;
+	int err;
+
+	if (!dev->netdev_ops->ndo_xdp_xmit)
+		return -EOPNOTSUPP;
+
+	err = xdp_ok_fwd_dev(dev, xdp->data_end - xdp->data);
+	if (unlikely(err))
+		return err;
+
+	xdpf = xdp_convert_buff_to_frame(xdp);
+	if (unlikely(!xdpf))
+		return -EOVERFLOW;
+
+	bq_enqueue(dev, xdpf, dev_rx);
+	return 0;
+}
+
+static struct xdp_buff *dev_map_run_prog(struct net_device *dev,
+					 struct xdp_buff *xdp,
+					 struct bpf_prog *xdp_prog)
+{
+	struct xdp_txq_info txq = { .dev = dev };
+	u32 act;
+
+	xdp_set_data_meta_invalid(xdp);
+	xdp->txq = &txq;
+
+	act = bpf_prog_run_xdp(xdp_prog, xdp);
+	switch (act) {
+	case XDP_PASS:
+		return xdp;
+	case XDP_DROP:
+		break;
+	default:
+		bpf_warn_invalid_xdp_action(act);
+		fallthrough;
+	case XDP_ABORTED:
+		trace_xdp_exception(dev, xdp_prog, act);
+		break;
+	}
+
+	xdp_return_buff(xdp);
+	return NULL;
+}
+
+int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
+		    struct net_device *dev_rx)
+{
+	return __xdp_enqueue(dev, xdp, dev_rx);
+}
+
+int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
+		    struct net_device *dev_rx)
+{
+	struct net_device *dev = dst->dev;
+
+	if (dst->xdp_prog) {
+		xdp = dev_map_run_prog(dev, xdp, dst->xdp_prog);
+		if (!xdp)
+			return 0;
+	}
+	return __xdp_enqueue(dev, xdp, dev_rx);
+}
+
+int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
+			     struct bpf_prog *xdp_prog)
+{
+	int err;
+
+	err = xdp_ok_fwd_dev(dst->dev, skb->len);
+	if (unlikely(err))
+		return err;
+	skb->dev = dst->dev;
+	generic_xdp_tx(skb, xdp_prog);
+
+	return 0;
+}
+
+static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_dtab_netdev *obj = __dev_map_lookup_elem(map, *(u32 *)key);
+
+	return obj ? &obj->val : NULL;
+}
+
+static void *dev_map_hash_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_dtab_netdev *obj = __dev_map_hash_lookup_elem(map,
+								*(u32 *)key);
+	return obj ? &obj->val : NULL;
+}
+
+static void __dev_map_entry_free(struct rcu_head *rcu)
+{
+	struct bpf_dtab_netdev *dev;
+
+	dev = container_of(rcu, struct bpf_dtab_netdev, rcu);
+	if (dev->xdp_prog)
+		bpf_prog_put(dev->xdp_prog);
+	dev_put(dev->dev);
+	kfree(dev);
+}
+
+static int dev_map_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+	struct bpf_dtab_netdev *old_dev;
+	int k = *(u32 *)key;
+
+	if (k >= map->max_entries)
+		return -EINVAL;
+
+	/* Use call_rcu() here to ensure any rcu critical sections have
+	 * completed as well as any flush operations because call_rcu
+	 * will wait for preempt-disable region to complete, NAPI in this
+	 * context.  And additionally, the driver tear down ensures all
+	 * soft irqs are complete before removing the net device in the
+	 * case of dev_put equals zero.
+	 */
+	old_dev = xchg(&dtab->netdev_map[k], NULL);
+	if (old_dev)
+		call_rcu(&old_dev->rcu, __dev_map_entry_free);
+	return 0;
+}
+
+static int dev_map_hash_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+	struct bpf_dtab_netdev *old_dev;
+	int k = *(u32 *)key;
+	unsigned long flags;
+	int ret = -ENOENT;
+
+	spin_lock_irqsave(&dtab->index_lock, flags);
+
+	old_dev = __dev_map_hash_lookup_elem(map, k);
+	if (old_dev) {
+		dtab->items--;
+		hlist_del_init_rcu(&old_dev->index_hlist);
+		call_rcu(&old_dev->rcu, __dev_map_entry_free);
+		ret = 0;
+	}
+	spin_unlock_irqrestore(&dtab->index_lock, flags);
+
+	return ret;
+}
+
+static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
+						    struct bpf_dtab *dtab,
+						    struct bpf_devmap_val *val,
+						    unsigned int idx)
+{
+	struct bpf_prog *prog = NULL;
+	struct bpf_dtab_netdev *dev;
+
+	dev = kmalloc_node(sizeof(*dev), GFP_ATOMIC | __GFP_NOWARN,
+			   dtab->map.numa_node);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	dev->dev = dev_get_by_index(net, val->ifindex);
+	if (!dev->dev)
+		goto err_out;
+
+	if (val->bpf_prog.fd > 0) {
+		prog = bpf_prog_get_type_dev(val->bpf_prog.fd,
+					     BPF_PROG_TYPE_XDP, false);
+		if (IS_ERR(prog))
+			goto err_put_dev;
+		if (prog->expected_attach_type != BPF_XDP_DEVMAP)
+			goto err_put_prog;
+	}
+
+	dev->idx = idx;
+	dev->dtab = dtab;
+	if (prog) {
+		dev->xdp_prog = prog;
+		dev->val.bpf_prog.id = prog->aux->id;
+	} else {
+		dev->xdp_prog = NULL;
+		dev->val.bpf_prog.id = 0;
+	}
+	dev->val.ifindex = val->ifindex;
+
+	return dev;
+err_put_prog:
+	bpf_prog_put(prog);
+err_put_dev:
+	dev_put(dev->dev);
+err_out:
+	kfree(dev);
+	return ERR_PTR(-EINVAL);
+}
+
+static int __dev_map_update_elem(struct net *net, struct bpf_map *map,
+				 void *key, void *value, u64 map_flags)
+{
+	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+	struct bpf_dtab_netdev *dev, *old_dev;
+	struct bpf_devmap_val val = {};
+	u32 i = *(u32 *)key;
+
+	if (unlikely(map_flags > BPF_EXIST))
+		return -EINVAL;
+	if (unlikely(i >= dtab->map.max_entries))
+		return -E2BIG;
+	if (unlikely(map_flags == BPF_NOEXIST))
+		return -EEXIST;
+
+	/* already verified value_size <= sizeof val */
+	memcpy(&val, value, map->value_size);
+
+	if (!val.ifindex) {
+		dev = NULL;
+		/* can not specify fd if ifindex is 0 */
+		if (val.bpf_prog.fd > 0)
+			return -EINVAL;
+	} else {
+		dev = __dev_map_alloc_node(net, dtab, &val, i);
+		if (IS_ERR(dev))
+			return PTR_ERR(dev);
+	}
+
+	/* Use call_rcu() here to ensure rcu critical sections have completed
+	 * Remembering the driver side flush operation will happen before the
+	 * net device is removed.
+	 */
+	old_dev = xchg(&dtab->netdev_map[i], dev);
+	if (old_dev)
+		call_rcu(&old_dev->rcu, __dev_map_entry_free);
+
+	return 0;
+}
+
+static int dev_map_update_elem(struct bpf_map *map, void *key, void *value,
+			       u64 map_flags)
+{
+	return __dev_map_update_elem(current->nsproxy->net_ns,
+				     map, key, value, map_flags);
+}
+
+static int __dev_map_hash_update_elem(struct net *net, struct bpf_map *map,
+				     void *key, void *value, u64 map_flags)
+{
+	struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+	struct bpf_dtab_netdev *dev, *old_dev;
+	struct bpf_devmap_val val = {};
+	u32 idx = *(u32 *)key;
+	unsigned long flags;
+	int err = -EEXIST;
+
+	/* already verified value_size <= sizeof val */
+	memcpy(&val, value, map->value_size);
+
+	if (unlikely(map_flags > BPF_EXIST || !val.ifindex))
+		return -EINVAL;
+
+	spin_lock_irqsave(&dtab->index_lock, flags);
+
+	old_dev = __dev_map_hash_lookup_elem(map, idx);
+	if (old_dev && (map_flags & BPF_NOEXIST))
+		goto out_err;
+
+	dev = __dev_map_alloc_node(net, dtab, &val, idx);
+	if (IS_ERR(dev)) {
+		err = PTR_ERR(dev);
+		goto out_err;
+	}
+
+	if (old_dev) {
+		hlist_del_rcu(&old_dev->index_hlist);
+	} else {
+		if (dtab->items >= dtab->map.max_entries) {
+			spin_unlock_irqrestore(&dtab->index_lock, flags);
+			call_rcu(&dev->rcu, __dev_map_entry_free);
+			return -E2BIG;
+		}
+		dtab->items++;
+	}
+
+	hlist_add_head_rcu(&dev->index_hlist,
+			   dev_map_index_hash(dtab, idx));
+	spin_unlock_irqrestore(&dtab->index_lock, flags);
+
+	if (old_dev)
+		call_rcu(&old_dev->rcu, __dev_map_entry_free);
+
+	return 0;
+
+out_err:
+	spin_unlock_irqrestore(&dtab->index_lock, flags);
+	return err;
+}
+
+static int dev_map_hash_update_elem(struct bpf_map *map, void *key, void *value,
+				   u64 map_flags)
+{
+	return __dev_map_hash_update_elem(current->nsproxy->net_ns,
+					 map, key, value, map_flags);
+}
+
+static int dev_map_btf_id;
+const struct bpf_map_ops dev_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc = dev_map_alloc,
+	.map_free = dev_map_free,
+	.map_get_next_key = dev_map_get_next_key,
+	.map_lookup_elem = dev_map_lookup_elem,
+	.map_update_elem = dev_map_update_elem,
+	.map_delete_elem = dev_map_delete_elem,
+	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_dtab",
+	.map_btf_id = &dev_map_btf_id,
+};
+
+static int dev_map_hash_map_btf_id;
+const struct bpf_map_ops dev_map_hash_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc = dev_map_alloc,
+	.map_free = dev_map_free,
+	.map_get_next_key = dev_map_hash_get_next_key,
+	.map_lookup_elem = dev_map_hash_lookup_elem,
+	.map_update_elem = dev_map_hash_update_elem,
+	.map_delete_elem = dev_map_hash_delete_elem,
+	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_dtab",
+	.map_btf_id = &dev_map_hash_map_btf_id,
+};
+
+static void dev_map_hash_remove_netdev(struct bpf_dtab *dtab,
+				       struct net_device *netdev)
+{
+	unsigned long flags;
+	u32 i;
+
+	spin_lock_irqsave(&dtab->index_lock, flags);
+	for (i = 0; i < dtab->n_buckets; i++) {
+		struct bpf_dtab_netdev *dev;
+		struct hlist_head *head;
+		struct hlist_node *next;
+
+		head = dev_map_index_hash(dtab, i);
+
+		hlist_for_each_entry_safe(dev, next, head, index_hlist) {
+			if (netdev != dev->dev)
+				continue;
+
+			dtab->items--;
+			hlist_del_rcu(&dev->index_hlist);
+			call_rcu(&dev->rcu, __dev_map_entry_free);
+		}
+	}
+	spin_unlock_irqrestore(&dtab->index_lock, flags);
+}
+
+static int dev_map_notification(struct notifier_block *notifier,
+				ulong event, void *ptr)
+{
+	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+	struct bpf_dtab *dtab;
+	int i, cpu;
+
+	switch (event) {
+	case NETDEV_REGISTER:
+		if (!netdev->netdev_ops->ndo_xdp_xmit || netdev->xdp_bulkq)
+			break;
+
+		/* will be freed in free_netdev() */
+		netdev->xdp_bulkq = alloc_percpu(struct xdp_dev_bulk_queue);
+		if (!netdev->xdp_bulkq)
+			return NOTIFY_BAD;
+
+		for_each_possible_cpu(cpu)
+			per_cpu_ptr(netdev->xdp_bulkq, cpu)->dev = netdev;
+		break;
+	case NETDEV_UNREGISTER:
+		/* This rcu_read_lock/unlock pair is needed because
+		 * dev_map_list is an RCU list AND to ensure a delete
+		 * operation does not free a netdev_map entry while we
+		 * are comparing it against the netdev being unregistered.
+		 */
+		rcu_read_lock();
+		list_for_each_entry_rcu(dtab, &dev_map_list, list) {
+			if (dtab->map.map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+				dev_map_hash_remove_netdev(dtab, netdev);
+				continue;
+			}
+
+			for (i = 0; i < dtab->map.max_entries; i++) {
+				struct bpf_dtab_netdev *dev, *odev;
+
+				dev = READ_ONCE(dtab->netdev_map[i]);
+				if (!dev || netdev != dev->dev)
+					continue;
+				odev = cmpxchg(&dtab->netdev_map[i], dev, NULL);
+				if (dev == odev)
+					call_rcu(&dev->rcu,
+						 __dev_map_entry_free);
+			}
+		}
+		rcu_read_unlock();
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block dev_map_notifier = {
+	.notifier_call = dev_map_notification,
+};
+
+static int __init dev_map_init(void)
+{
+	int cpu;
+
+	/* Assure tracepoint shadow struct _bpf_dtab_netdev is in sync */
+	BUILD_BUG_ON(offsetof(struct bpf_dtab_netdev, dev) !=
+		     offsetof(struct _bpf_dtab_netdev, dev));
+	register_netdevice_notifier(&dev_map_notifier);
+
+	for_each_possible_cpu(cpu)
+		INIT_LIST_HEAD(&per_cpu(dev_flush_list, cpu));
+	return 0;
+}
+
+subsys_initcall(dev_map_init);
diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
new file mode 100644
index 000000000..ff1dd7d45
--- /dev/null
+++ b/kernel/bpf/disasm.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016 Facebook
+ */
+
+#include <linux/bpf.h>
+
+#include "disasm.h"
+
+#define __BPF_FUNC_STR_FN(x) [BPF_FUNC_ ## x] = __stringify(bpf_ ## x)
+static const char * const func_id_str[] = {
+	__BPF_FUNC_MAPPER(__BPF_FUNC_STR_FN)
+};
+#undef __BPF_FUNC_STR_FN
+
+static const char *__func_get_name(const struct bpf_insn_cbs *cbs,
+				   const struct bpf_insn *insn,
+				   char *buff, size_t len)
+{
+	BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID);
+
+	if (insn->src_reg != BPF_PSEUDO_CALL &&
+	    insn->imm >= 0 && insn->imm < __BPF_FUNC_MAX_ID &&
+	    func_id_str[insn->imm])
+		return func_id_str[insn->imm];
+
+	if (cbs && cbs->cb_call)
+		return cbs->cb_call(cbs->private_data, insn);
+
+	if (insn->src_reg == BPF_PSEUDO_CALL)
+		snprintf(buff, len, "%+d", insn->imm);
+
+	return buff;
+}
+
+static const char *__func_imm_name(const struct bpf_insn_cbs *cbs,
+				   const struct bpf_insn *insn,
+				   u64 full_imm, char *buff, size_t len)
+{
+	if (cbs && cbs->cb_imm)
+		return cbs->cb_imm(cbs->private_data, insn, full_imm);
+
+	snprintf(buff, len, "0x%llx", (unsigned long long)full_imm);
+	return buff;
+}
+
+const char *func_id_name(int id)
+{
+	if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id])
+		return func_id_str[id];
+	else
+		return "unknown";
+}
+
+const char *const bpf_class_string[8] = {
+	[BPF_LD]    = "ld",
+	[BPF_LDX]   = "ldx",
+	[BPF_ST]    = "st",
+	[BPF_STX]   = "stx",
+	[BPF_ALU]   = "alu",
+	[BPF_JMP]   = "jmp",
+	[BPF_JMP32] = "jmp32",
+	[BPF_ALU64] = "alu64",
+};
+
+const char *const bpf_alu_string[16] = {
+	[BPF_ADD >> 4]  = "+=",
+	[BPF_SUB >> 4]  = "-=",
+	[BPF_MUL >> 4]  = "*=",
+	[BPF_DIV >> 4]  = "/=",
+	[BPF_OR  >> 4]  = "|=",
+	[BPF_AND >> 4]  = "&=",
+	[BPF_LSH >> 4]  = "<<=",
+	[BPF_RSH >> 4]  = ">>=",
+	[BPF_NEG >> 4]  = "neg",
+	[BPF_MOD >> 4]  = "%=",
+	[BPF_XOR >> 4]  = "^=",
+	[BPF_MOV >> 4]  = "=",
+	[BPF_ARSH >> 4] = "s>>=",
+	[BPF_END >> 4]  = "endian",
+};
+
+static const char *const bpf_ldst_string[] = {
+	[BPF_W >> 3]  = "u32",
+	[BPF_H >> 3]  = "u16",
+	[BPF_B >> 3]  = "u8",
+	[BPF_DW >> 3] = "u64",
+};
+
+static const char *const bpf_jmp_string[16] = {
+	[BPF_JA >> 4]   = "jmp",
+	[BPF_JEQ >> 4]  = "==",
+	[BPF_JGT >> 4]  = ">",
+	[BPF_JLT >> 4]  = "<",
+	[BPF_JGE >> 4]  = ">=",
+	[BPF_JLE >> 4]  = "<=",
+	[BPF_JSET >> 4] = "&",
+	[BPF_JNE >> 4]  = "!=",
+	[BPF_JSGT >> 4] = "s>",
+	[BPF_JSLT >> 4] = "s<",
+	[BPF_JSGE >> 4] = "s>=",
+	[BPF_JSLE >> 4] = "s<=",
+	[BPF_CALL >> 4] = "call",
+	[BPF_EXIT >> 4] = "exit",
+};
+
+static void print_bpf_end_insn(bpf_insn_print_t verbose,
+			       void *private_data,
+			       const struct bpf_insn *insn)
+{
+	verbose(private_data, "(%02x) r%d = %s%d r%d\n",
+		insn->code, insn->dst_reg,
+		BPF_SRC(insn->code) == BPF_TO_BE ? "be" : "le",
+		insn->imm, insn->dst_reg);
+}
+
+void print_bpf_insn(const struct bpf_insn_cbs *cbs,
+		    const struct bpf_insn *insn,
+		    bool allow_ptr_leaks)
+{
+	const bpf_insn_print_t verbose = cbs->cb_print;
+	u8 class = BPF_CLASS(insn->code);
+
+	if (class == BPF_ALU || class == BPF_ALU64) {
+		if (BPF_OP(insn->code) == BPF_END) {
+			if (class == BPF_ALU64)
+				verbose(cbs->private_data, "BUG_alu64_%02x\n", insn->code);
+			else
+				print_bpf_end_insn(verbose, cbs->private_data, insn);
+		} else if (BPF_OP(insn->code) == BPF_NEG) {
+			verbose(cbs->private_data, "(%02x) %c%d = -%c%d\n",
+				insn->code, class == BPF_ALU ? 'w' : 'r',
+				insn->dst_reg, class == BPF_ALU ? 'w' : 'r',
+				insn->dst_reg);
+		} else if (BPF_SRC(insn->code) == BPF_X) {
+			verbose(cbs->private_data, "(%02x) %c%d %s %c%d\n",
+				insn->code, class == BPF_ALU ? 'w' : 'r',
+				insn->dst_reg,
+				bpf_alu_string[BPF_OP(insn->code) >> 4],
+				class == BPF_ALU ? 'w' : 'r',
+				insn->src_reg);
+		} else {
+			verbose(cbs->private_data, "(%02x) %c%d %s %d\n",
+				insn->code, class == BPF_ALU ? 'w' : 'r',
+				insn->dst_reg,
+				bpf_alu_string[BPF_OP(insn->code) >> 4],
+				insn->imm);
+		}
+	} else if (class == BPF_STX) {
+		if (BPF_MODE(insn->code) == BPF_MEM)
+			verbose(cbs->private_data, "(%02x) *(%s *)(r%d %+d) = r%d\n",
+				insn->code,
+				bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
+				insn->dst_reg,
+				insn->off, insn->src_reg);
+		else if (BPF_MODE(insn->code) == BPF_XADD)
+			verbose(cbs->private_data, "(%02x) lock *(%s *)(r%d %+d) += r%d\n",
+				insn->code,
+				bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
+				insn->dst_reg, insn->off,
+				insn->src_reg);
+		else
+			verbose(cbs->private_data, "BUG_%02x\n", insn->code);
+	} else if (class == BPF_ST) {
+		if (BPF_MODE(insn->code) == BPF_MEM) {
+			verbose(cbs->private_data, "(%02x) *(%s *)(r%d %+d) = %d\n",
+				insn->code,
+				bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
+				insn->dst_reg,
+				insn->off, insn->imm);
+		} else if (BPF_MODE(insn->code) == 0xc0 /* BPF_NOSPEC, no UAPI */) {
+			verbose(cbs->private_data, "(%02x) nospec\n", insn->code);
+		} else {
+			verbose(cbs->private_data, "BUG_st_%02x\n", insn->code);
+		}
+	} else if (class == BPF_LDX) {
+		if (BPF_MODE(insn->code) != BPF_MEM) {
+			verbose(cbs->private_data, "BUG_ldx_%02x\n", insn->code);
+			return;
+		}
+		verbose(cbs->private_data, "(%02x) r%d = *(%s *)(r%d %+d)\n",
+			insn->code, insn->dst_reg,
+			bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
+			insn->src_reg, insn->off);
+	} else if (class == BPF_LD) {
+		if (BPF_MODE(insn->code) == BPF_ABS) {
+			verbose(cbs->private_data, "(%02x) r0 = *(%s *)skb[%d]\n",
+				insn->code,
+				bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
+				insn->imm);
+		} else if (BPF_MODE(insn->code) == BPF_IND) {
+			verbose(cbs->private_data, "(%02x) r0 = *(%s *)skb[r%d + %d]\n",
+				insn->code,
+				bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
+				insn->src_reg, insn->imm);
+		} else if (BPF_MODE(insn->code) == BPF_IMM &&
+			   BPF_SIZE(insn->code) == BPF_DW) {
+			/* At this point, we already made sure that the second
+			 * part of the ldimm64 insn is accessible.
+			 */
+			u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;
+			bool is_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD ||
+				      insn->src_reg == BPF_PSEUDO_MAP_VALUE;
+			char tmp[64];
+
+			if (is_ptr && !allow_ptr_leaks)
+				imm = 0;
+
+			verbose(cbs->private_data, "(%02x) r%d = %s\n",
+				insn->code, insn->dst_reg,
+				__func_imm_name(cbs, insn, imm,
+						tmp, sizeof(tmp)));
+		} else {
+			verbose(cbs->private_data, "BUG_ld_%02x\n", insn->code);
+			return;
+		}
+	} else if (class == BPF_JMP32 || class == BPF_JMP) {
+		u8 opcode = BPF_OP(insn->code);
+
+		if (opcode == BPF_CALL) {
+			char tmp[64];
+
+			if (insn->src_reg == BPF_PSEUDO_CALL) {
+				verbose(cbs->private_data, "(%02x) call pc%s\n",
+					insn->code,
+					__func_get_name(cbs, insn,
+							tmp, sizeof(tmp)));
+			} else {
+				strcpy(tmp, "unknown");
+				verbose(cbs->private_data, "(%02x) call %s#%d\n", insn->code,
+					__func_get_name(cbs, insn,
+							tmp, sizeof(tmp)),
+					insn->imm);
+			}
+		} else if (insn->code == (BPF_JMP | BPF_JA)) {
+			verbose(cbs->private_data, "(%02x) goto pc%+d\n",
+				insn->code, insn->off);
+		} else if (insn->code == (BPF_JMP | BPF_EXIT)) {
+			verbose(cbs->private_data, "(%02x) exit\n", insn->code);
+		} else if (BPF_SRC(insn->code) == BPF_X) {
+			verbose(cbs->private_data,
+				"(%02x) if %c%d %s %c%d goto pc%+d\n",
+				insn->code, class == BPF_JMP32 ? 'w' : 'r',
+				insn->dst_reg,
+				bpf_jmp_string[BPF_OP(insn->code) >> 4],
+				class == BPF_JMP32 ? 'w' : 'r',
+				insn->src_reg, insn->off);
+		} else {
+			verbose(cbs->private_data,
+				"(%02x) if %c%d %s 0x%x goto pc%+d\n",
+				insn->code, class == BPF_JMP32 ? 'w' : 'r',
+				insn->dst_reg,
+				bpf_jmp_string[BPF_OP(insn->code) >> 4],
+				insn->imm, insn->off);
+		}
+	} else {
+		verbose(cbs->private_data, "(%02x) %s\n",
+			insn->code, bpf_class_string[class]);
+	}
+}
diff --git a/kernel/bpf/disasm.h b/kernel/bpf/disasm.h
new file mode 100644
index 000000000..e546b18d2
--- /dev/null
+++ b/kernel/bpf/disasm.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016 Facebook
+ */
+
+#ifndef __BPF_DISASM_H__
+#define __BPF_DISASM_H__
+
+#include <linux/bpf.h>
+#include <linux/kernel.h>
+#include <linux/stringify.h>
+#ifndef __KERNEL__
+#include <stdio.h>
+#include <string.h>
+#endif
+
+extern const char *const bpf_alu_string[16];
+extern const char *const bpf_class_string[8];
+
+const char *func_id_name(int id);
+
+typedef __printf(2, 3) void (*bpf_insn_print_t)(void *private_data,
+						const char *, ...);
+typedef const char *(*bpf_insn_revmap_call_t)(void *private_data,
+					      const struct bpf_insn *insn);
+typedef const char *(*bpf_insn_print_imm_t)(void *private_data,
+					    const struct bpf_insn *insn,
+					    __u64 full_imm);
+
+struct bpf_insn_cbs {
+	bpf_insn_print_t	cb_print;
+	bpf_insn_revmap_call_t	cb_call;
+	bpf_insn_print_imm_t	cb_imm;
+	void			*private_data;
+};
+
+void print_bpf_insn(const struct bpf_insn_cbs *cbs,
+		    const struct bpf_insn *insn,
+		    bool allow_ptr_leaks);
+#endif
diff --git a/kernel/bpf/dispatcher.c b/kernel/bpf/dispatcher.c
new file mode 100644
index 000000000..2444bd15c
--- /dev/null
+++ b/kernel/bpf/dispatcher.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2019 Intel Corporation. */
+
+#include <linux/hash.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+
+/* The BPF dispatcher is a multiway branch code generator. The
+ * dispatcher is a mechanism to avoid the performance penalty of an
+ * indirect call, which is expensive when retpolines are enabled. A
+ * dispatch client registers a BPF program into the dispatcher, and if
+ * there is available room in the dispatcher a direct call to the BPF
+ * program will be generated. All calls to the BPF programs called via
+ * the dispatcher will then be a direct call, instead of an
+ * indirect. The dispatcher hijacks a trampoline function it via the
+ * __fentry__ of the trampoline. The trampoline function has the
+ * following signature:
+ *
+ * unsigned int trampoline(const void *ctx, const struct bpf_insn *insnsi,
+ *                         unsigned int (*bpf_func)(const void *,
+ *                                                  const struct bpf_insn *));
+ */
+
+static struct bpf_dispatcher_prog *bpf_dispatcher_find_prog(
+	struct bpf_dispatcher *d, struct bpf_prog *prog)
+{
+	int i;
+
+	for (i = 0; i < BPF_DISPATCHER_MAX; i++) {
+		if (prog == d->progs[i].prog)
+			return &d->progs[i];
+	}
+	return NULL;
+}
+
+static struct bpf_dispatcher_prog *bpf_dispatcher_find_free(
+	struct bpf_dispatcher *d)
+{
+	return bpf_dispatcher_find_prog(d, NULL);
+}
+
+static bool bpf_dispatcher_add_prog(struct bpf_dispatcher *d,
+				    struct bpf_prog *prog)
+{
+	struct bpf_dispatcher_prog *entry;
+
+	if (!prog)
+		return false;
+
+	entry = bpf_dispatcher_find_prog(d, prog);
+	if (entry) {
+		refcount_inc(&entry->users);
+		return false;
+	}
+
+	entry = bpf_dispatcher_find_free(d);
+	if (!entry)
+		return false;
+
+	bpf_prog_inc(prog);
+	entry->prog = prog;
+	refcount_set(&entry->users, 1);
+	d->num_progs++;
+	return true;
+}
+
+static bool bpf_dispatcher_remove_prog(struct bpf_dispatcher *d,
+				       struct bpf_prog *prog)
+{
+	struct bpf_dispatcher_prog *entry;
+
+	if (!prog)
+		return false;
+
+	entry = bpf_dispatcher_find_prog(d, prog);
+	if (!entry)
+		return false;
+
+	if (refcount_dec_and_test(&entry->users)) {
+		entry->prog = NULL;
+		bpf_prog_put(prog);
+		d->num_progs--;
+		return true;
+	}
+	return false;
+}
+
+int __weak arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs)
+{
+	return -ENOTSUPP;
+}
+
+static int bpf_dispatcher_prepare(struct bpf_dispatcher *d, void *image)
+{
+	s64 ips[BPF_DISPATCHER_MAX] = {}, *ipsp = &ips[0];
+	int i;
+
+	for (i = 0; i < BPF_DISPATCHER_MAX; i++) {
+		if (d->progs[i].prog)
+			*ipsp++ = (s64)(uintptr_t)d->progs[i].prog->bpf_func;
+	}
+	return arch_prepare_bpf_dispatcher(image, &ips[0], d->num_progs);
+}
+
+static void bpf_dispatcher_update(struct bpf_dispatcher *d, int prev_num_progs)
+{
+	void *old, *new;
+	u32 noff;
+	int err;
+
+	if (!prev_num_progs) {
+		old = NULL;
+		noff = 0;
+	} else {
+		old = d->image + d->image_off;
+		noff = d->image_off ^ (PAGE_SIZE / 2);
+	}
+
+	new = d->num_progs ? d->image + noff : NULL;
+	if (new) {
+		if (bpf_dispatcher_prepare(d, new))
+			return;
+	}
+
+	err = bpf_arch_text_poke(d->func, BPF_MOD_JUMP, old, new);
+	if (err || !new)
+		return;
+
+	d->image_off = noff;
+}
+
+void bpf_dispatcher_change_prog(struct bpf_dispatcher *d, struct bpf_prog *from,
+				struct bpf_prog *to)
+{
+	bool changed = false;
+	int prev_num_progs;
+
+	if (from == to)
+		return;
+
+	mutex_lock(&d->mutex);
+	if (!d->image) {
+		d->image = bpf_jit_alloc_exec_page();
+		if (!d->image)
+			goto out;
+		bpf_image_ksym_add(d->image, &d->ksym);
+	}
+
+	prev_num_progs = d->num_progs;
+	changed |= bpf_dispatcher_remove_prog(d, from);
+	changed |= bpf_dispatcher_add_prog(d, to);
+
+	if (!changed)
+		goto out;
+
+	bpf_dispatcher_update(d, prev_num_progs);
+out:
+	mutex_unlock(&d->mutex);
+}
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
new file mode 100644
index 000000000..0ce445aad
--- /dev/null
+++ b/kernel/bpf/hashtab.c
@@ -0,0 +1,2140 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016 Facebook
+ */
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/jhash.h>
+#include <linux/filter.h>
+#include <linux/rculist_nulls.h>
+#include <linux/random.h>
+#include <uapi/linux/btf.h>
+#include <linux/rcupdate_trace.h>
+#include "percpu_freelist.h"
+#include "bpf_lru_list.h"
+#include "map_in_map.h"
+
+#define HTAB_CREATE_FLAG_MASK						\
+	(BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE |	\
+	 BPF_F_ACCESS_MASK | BPF_F_ZERO_SEED)
+
+#define BATCH_OPS(_name)			\
+	.map_lookup_batch =			\
+	_name##_map_lookup_batch,		\
+	.map_lookup_and_delete_batch =		\
+	_name##_map_lookup_and_delete_batch,	\
+	.map_update_batch =			\
+	generic_map_update_batch,		\
+	.map_delete_batch =			\
+	generic_map_delete_batch
+
+/*
+ * The bucket lock has two protection scopes:
+ *
+ * 1) Serializing concurrent operations from BPF programs on differrent
+ *    CPUs
+ *
+ * 2) Serializing concurrent operations from BPF programs and sys_bpf()
+ *
+ * BPF programs can execute in any context including perf, kprobes and
+ * tracing. As there are almost no limits where perf, kprobes and tracing
+ * can be invoked from the lock operations need to be protected against
+ * deadlocks. Deadlocks can be caused by recursion and by an invocation in
+ * the lock held section when functions which acquire this lock are invoked
+ * from sys_bpf(). BPF recursion is prevented by incrementing the per CPU
+ * variable bpf_prog_active, which prevents BPF programs attached to perf
+ * events, kprobes and tracing to be invoked before the prior invocation
+ * from one of these contexts completed. sys_bpf() uses the same mechanism
+ * by pinning the task to the current CPU and incrementing the recursion
+ * protection accross the map operation.
+ *
+ * This has subtle implications on PREEMPT_RT. PREEMPT_RT forbids certain
+ * operations like memory allocations (even with GFP_ATOMIC) from atomic
+ * contexts. This is required because even with GFP_ATOMIC the memory
+ * allocator calls into code pathes which acquire locks with long held lock
+ * sections. To ensure the deterministic behaviour these locks are regular
+ * spinlocks, which are converted to 'sleepable' spinlocks on RT. The only
+ * true atomic contexts on an RT kernel are the low level hardware
+ * handling, scheduling, low level interrupt handling, NMIs etc. None of
+ * these contexts should ever do memory allocations.
+ *
+ * As regular device interrupt handlers and soft interrupts are forced into
+ * thread context, the existing code which does
+ *   spin_lock*(); alloc(GPF_ATOMIC); spin_unlock*();
+ * just works.
+ *
+ * In theory the BPF locks could be converted to regular spinlocks as well,
+ * but the bucket locks and percpu_freelist locks can be taken from
+ * arbitrary contexts (perf, kprobes, tracepoints) which are required to be
+ * atomic contexts even on RT. These mechanisms require preallocated maps,
+ * so there is no need to invoke memory allocations within the lock held
+ * sections.
+ *
+ * BPF maps which need dynamic allocation are only used from (forced)
+ * thread context on RT and can therefore use regular spinlocks which in
+ * turn allows to invoke memory allocations from the lock held section.
+ *
+ * On a non RT kernel this distinction is neither possible nor required.
+ * spinlock maps to raw_spinlock and the extra code is optimized out by the
+ * compiler.
+ */
+struct bucket {
+	struct hlist_nulls_head head;
+	union {
+		raw_spinlock_t raw_lock;
+		spinlock_t     lock;
+	};
+};
+
+struct bpf_htab {
+	struct bpf_map map;
+	struct bucket *buckets;
+	void *elems;
+	union {
+		struct pcpu_freelist freelist;
+		struct bpf_lru lru;
+	};
+	struct htab_elem *__percpu *extra_elems;
+	atomic_t count;	/* number of elements in this hashtable */
+	u32 n_buckets;	/* number of hash buckets */
+	u32 elem_size;	/* size of each element in bytes */
+	u32 hashrnd;
+};
+
+/* each htab element is struct htab_elem + key + value */
+struct htab_elem {
+	union {
+		struct hlist_nulls_node hash_node;
+		struct {
+			void *padding;
+			union {
+				struct bpf_htab *htab;
+				struct pcpu_freelist_node fnode;
+				struct htab_elem *batch_flink;
+			};
+		};
+	};
+	union {
+		struct rcu_head rcu;
+		struct bpf_lru_node lru_node;
+	};
+	u32 hash;
+	char key[] __aligned(8);
+};
+
+static inline bool htab_is_prealloc(const struct bpf_htab *htab)
+{
+	return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
+}
+
+static inline bool htab_use_raw_lock(const struct bpf_htab *htab)
+{
+	return (!IS_ENABLED(CONFIG_PREEMPT_RT) || htab_is_prealloc(htab));
+}
+
+static void htab_init_buckets(struct bpf_htab *htab)
+{
+	unsigned i;
+
+	for (i = 0; i < htab->n_buckets; i++) {
+		INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
+		if (htab_use_raw_lock(htab))
+			raw_spin_lock_init(&htab->buckets[i].raw_lock);
+		else
+			spin_lock_init(&htab->buckets[i].lock);
+	}
+}
+
+static inline unsigned long htab_lock_bucket(const struct bpf_htab *htab,
+					     struct bucket *b)
+{
+	unsigned long flags;
+
+	if (htab_use_raw_lock(htab))
+		raw_spin_lock_irqsave(&b->raw_lock, flags);
+	else
+		spin_lock_irqsave(&b->lock, flags);
+	return flags;
+}
+
+static inline void htab_unlock_bucket(const struct bpf_htab *htab,
+				      struct bucket *b,
+				      unsigned long flags)
+{
+	if (htab_use_raw_lock(htab))
+		raw_spin_unlock_irqrestore(&b->raw_lock, flags);
+	else
+		spin_unlock_irqrestore(&b->lock, flags);
+}
+
+static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
+
+static bool htab_is_lru(const struct bpf_htab *htab)
+{
+	return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH ||
+		htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
+}
+
+static bool htab_is_percpu(const struct bpf_htab *htab)
+{
+	return htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+		htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
+}
+
+static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
+				     void __percpu *pptr)
+{
+	*(void __percpu **)(l->key + key_size) = pptr;
+}
+
+static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size)
+{
+	return *(void __percpu **)(l->key + key_size);
+}
+
+static void *fd_htab_map_get_ptr(const struct bpf_map *map, struct htab_elem *l)
+{
+	return *(void **)(l->key + roundup(map->key_size, 8));
+}
+
+static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
+{
+	return (struct htab_elem *) (htab->elems + i * htab->elem_size);
+}
+
+static void htab_free_elems(struct bpf_htab *htab)
+{
+	int i;
+
+	if (!htab_is_percpu(htab))
+		goto free_elems;
+
+	for (i = 0; i < htab->map.max_entries; i++) {
+		void __percpu *pptr;
+
+		pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
+					 htab->map.key_size);
+		free_percpu(pptr);
+		cond_resched();
+	}
+free_elems:
+	bpf_map_area_free(htab->elems);
+}
+
+/* The LRU list has a lock (lru_lock). Each htab bucket has a lock
+ * (bucket_lock). If both locks need to be acquired together, the lock
+ * order is always lru_lock -> bucket_lock and this only happens in
+ * bpf_lru_list.c logic. For example, certain code path of
+ * bpf_lru_pop_free(), which is called by function prealloc_lru_pop(),
+ * will acquire lru_lock first followed by acquiring bucket_lock.
+ *
+ * In hashtab.c, to avoid deadlock, lock acquisition of
+ * bucket_lock followed by lru_lock is not allowed. In such cases,
+ * bucket_lock needs to be released first before acquiring lru_lock.
+ */
+static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key,
+					  u32 hash)
+{
+	struct bpf_lru_node *node = bpf_lru_pop_free(&htab->lru, hash);
+	struct htab_elem *l;
+
+	if (node) {
+		l = container_of(node, struct htab_elem, lru_node);
+		memcpy(l->key, key, htab->map.key_size);
+		return l;
+	}
+
+	return NULL;
+}
+
+static int prealloc_init(struct bpf_htab *htab)
+{
+	u32 num_entries = htab->map.max_entries;
+	int err = -ENOMEM, i;
+
+	if (!htab_is_percpu(htab) && !htab_is_lru(htab))
+		num_entries += num_possible_cpus();
+
+	htab->elems = bpf_map_area_alloc(htab->elem_size * num_entries,
+					 htab->map.numa_node);
+	if (!htab->elems)
+		return -ENOMEM;
+
+	if (!htab_is_percpu(htab))
+		goto skip_percpu_elems;
+
+	for (i = 0; i < num_entries; i++) {
+		u32 size = round_up(htab->map.value_size, 8);
+		void __percpu *pptr;
+
+		pptr = __alloc_percpu_gfp(size, 8, GFP_USER | __GFP_NOWARN);
+		if (!pptr)
+			goto free_elems;
+		htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
+				  pptr);
+		cond_resched();
+	}
+
+skip_percpu_elems:
+	if (htab_is_lru(htab))
+		err = bpf_lru_init(&htab->lru,
+				   htab->map.map_flags & BPF_F_NO_COMMON_LRU,
+				   offsetof(struct htab_elem, hash) -
+				   offsetof(struct htab_elem, lru_node),
+				   htab_lru_map_delete_node,
+				   htab);
+	else
+		err = pcpu_freelist_init(&htab->freelist);
+
+	if (err)
+		goto free_elems;
+
+	if (htab_is_lru(htab))
+		bpf_lru_populate(&htab->lru, htab->elems,
+				 offsetof(struct htab_elem, lru_node),
+				 htab->elem_size, num_entries);
+	else
+		pcpu_freelist_populate(&htab->freelist,
+				       htab->elems + offsetof(struct htab_elem, fnode),
+				       htab->elem_size, num_entries);
+
+	return 0;
+
+free_elems:
+	htab_free_elems(htab);
+	return err;
+}
+
+static void prealloc_destroy(struct bpf_htab *htab)
+{
+	htab_free_elems(htab);
+
+	if (htab_is_lru(htab))
+		bpf_lru_destroy(&htab->lru);
+	else
+		pcpu_freelist_destroy(&htab->freelist);
+}
+
+static int alloc_extra_elems(struct bpf_htab *htab)
+{
+	struct htab_elem *__percpu *pptr, *l_new;
+	struct pcpu_freelist_node *l;
+	int cpu;
+
+	pptr = __alloc_percpu_gfp(sizeof(struct htab_elem *), 8,
+				  GFP_USER | __GFP_NOWARN);
+	if (!pptr)
+		return -ENOMEM;
+
+	for_each_possible_cpu(cpu) {
+		l = pcpu_freelist_pop(&htab->freelist);
+		/* pop will succeed, since prealloc_init()
+		 * preallocated extra num_possible_cpus elements
+		 */
+		l_new = container_of(l, struct htab_elem, fnode);
+		*per_cpu_ptr(pptr, cpu) = l_new;
+	}
+	htab->extra_elems = pptr;
+	return 0;
+}
+
+/* Called from syscall */
+static int htab_map_alloc_check(union bpf_attr *attr)
+{
+	bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+		       attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
+	bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
+		    attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
+	/* percpu_lru means each cpu has its own LRU list.
+	 * it is different from BPF_MAP_TYPE_PERCPU_HASH where
+	 * the map's value itself is percpu.  percpu_lru has
+	 * nothing to do with the map's value.
+	 */
+	bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
+	bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
+	bool zero_seed = (attr->map_flags & BPF_F_ZERO_SEED);
+	int numa_node = bpf_map_attr_numa_node(attr);
+
+	BUILD_BUG_ON(offsetof(struct htab_elem, htab) !=
+		     offsetof(struct htab_elem, hash_node.pprev));
+	BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) !=
+		     offsetof(struct htab_elem, hash_node.pprev));
+
+	if (lru && !bpf_capable())
+		/* LRU implementation is much complicated than other
+		 * maps.  Hence, limit to CAP_BPF.
+		 */
+		return -EPERM;
+
+	if (zero_seed && !capable(CAP_SYS_ADMIN))
+		/* Guard against local DoS, and discourage production use. */
+		return -EPERM;
+
+	if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags))
+		return -EINVAL;
+
+	if (!lru && percpu_lru)
+		return -EINVAL;
+
+	if (lru && !prealloc)
+		return -ENOTSUPP;
+
+	if (numa_node != NUMA_NO_NODE && (percpu || percpu_lru))
+		return -EINVAL;
+
+	/* check sanity of attributes.
+	 * value_size == 0 may be allowed in the future to use map as a set
+	 */
+	if (attr->max_entries == 0 || attr->key_size == 0 ||
+	    attr->value_size == 0)
+		return -EINVAL;
+
+	if (attr->key_size > MAX_BPF_STACK)
+		/* eBPF programs initialize keys on stack, so they cannot be
+		 * larger than max stack size
+		 */
+		return -E2BIG;
+
+	if (attr->value_size >= KMALLOC_MAX_SIZE -
+	    MAX_BPF_STACK - sizeof(struct htab_elem))
+		/* if value_size is bigger, the user space won't be able to
+		 * access the elements via bpf syscall. This check also makes
+		 * sure that the elem_size doesn't overflow and it's
+		 * kmalloc-able later in htab_map_update_elem()
+		 */
+		return -E2BIG;
+
+	return 0;
+}
+
+static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
+{
+	bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+		       attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
+	bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
+		    attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
+	/* percpu_lru means each cpu has its own LRU list.
+	 * it is different from BPF_MAP_TYPE_PERCPU_HASH where
+	 * the map's value itself is percpu.  percpu_lru has
+	 * nothing to do with the map's value.
+	 */
+	bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
+	bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
+	struct bpf_htab *htab;
+	u64 cost;
+	int err;
+
+	htab = kzalloc(sizeof(*htab), GFP_USER);
+	if (!htab)
+		return ERR_PTR(-ENOMEM);
+
+	bpf_map_init_from_attr(&htab->map, attr);
+
+	if (percpu_lru) {
+		/* ensure each CPU's lru list has >=1 elements.
+		 * since we are at it, make each lru list has the same
+		 * number of elements.
+		 */
+		htab->map.max_entries = roundup(attr->max_entries,
+						num_possible_cpus());
+		if (htab->map.max_entries < attr->max_entries)
+			htab->map.max_entries = rounddown(attr->max_entries,
+							  num_possible_cpus());
+	}
+
+	/* hash table size must be power of 2 */
+	htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
+
+	htab->elem_size = sizeof(struct htab_elem) +
+			  round_up(htab->map.key_size, 8);
+	if (percpu)
+		htab->elem_size += sizeof(void *);
+	else
+		htab->elem_size += round_up(htab->map.value_size, 8);
+
+	err = -E2BIG;
+	/* prevent zero size kmalloc and check for u32 overflow */
+	if (htab->n_buckets == 0 ||
+	    htab->n_buckets > U32_MAX / sizeof(struct bucket))
+		goto free_htab;
+
+	cost = (u64) htab->n_buckets * sizeof(struct bucket) +
+	       (u64) htab->elem_size * htab->map.max_entries;
+
+	if (percpu)
+		cost += (u64) round_up(htab->map.value_size, 8) *
+			num_possible_cpus() * htab->map.max_entries;
+	else
+	       cost += (u64) htab->elem_size * num_possible_cpus();
+
+	/* if map size is larger than memlock limit, reject it */
+	err = bpf_map_charge_init(&htab->map.memory, cost);
+	if (err)
+		goto free_htab;
+
+	err = -ENOMEM;
+	htab->buckets = bpf_map_area_alloc(htab->n_buckets *
+					   sizeof(struct bucket),
+					   htab->map.numa_node);
+	if (!htab->buckets)
+		goto free_charge;
+
+	if (htab->map.map_flags & BPF_F_ZERO_SEED)
+		htab->hashrnd = 0;
+	else
+		htab->hashrnd = get_random_int();
+
+	htab_init_buckets(htab);
+
+	if (prealloc) {
+		err = prealloc_init(htab);
+		if (err)
+			goto free_buckets;
+
+		if (!percpu && !lru) {
+			/* lru itself can remove the least used element, so
+			 * there is no need for an extra elem during map_update.
+			 */
+			err = alloc_extra_elems(htab);
+			if (err)
+				goto free_prealloc;
+		}
+	}
+
+	return &htab->map;
+
+free_prealloc:
+	prealloc_destroy(htab);
+free_buckets:
+	bpf_map_area_free(htab->buckets);
+free_charge:
+	bpf_map_charge_finish(&htab->map.memory);
+free_htab:
+	kfree(htab);
+	return ERR_PTR(err);
+}
+
+static inline u32 htab_map_hash(const void *key, u32 key_len, u32 hashrnd)
+{
+	return jhash(key, key_len, hashrnd);
+}
+
+static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
+{
+	return &htab->buckets[hash & (htab->n_buckets - 1)];
+}
+
+static inline struct hlist_nulls_head *select_bucket(struct bpf_htab *htab, u32 hash)
+{
+	return &__select_bucket(htab, hash)->head;
+}
+
+/* this lookup function can only be called with bucket lock taken */
+static struct htab_elem *lookup_elem_raw(struct hlist_nulls_head *head, u32 hash,
+					 void *key, u32 key_size)
+{
+	struct hlist_nulls_node *n;
+	struct htab_elem *l;
+
+	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
+		if (l->hash == hash && !memcmp(&l->key, key, key_size))
+			return l;
+
+	return NULL;
+}
+
+/* can be called without bucket lock. it will repeat the loop in
+ * the unlikely event when elements moved from one bucket into another
+ * while link list is being walked
+ */
+static struct htab_elem *lookup_nulls_elem_raw(struct hlist_nulls_head *head,
+					       u32 hash, void *key,
+					       u32 key_size, u32 n_buckets)
+{
+	struct hlist_nulls_node *n;
+	struct htab_elem *l;
+
+again:
+	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
+		if (l->hash == hash && !memcmp(&l->key, key, key_size))
+			return l;
+
+	if (unlikely(get_nulls_value(n) != (hash & (n_buckets - 1))))
+		goto again;
+
+	return NULL;
+}
+
+/* Called from syscall or from eBPF program directly, so
+ * arguments have to match bpf_map_lookup_elem() exactly.
+ * The return value is adjusted by BPF instructions
+ * in htab_map_gen_lookup().
+ */
+static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct hlist_nulls_head *head;
+	struct htab_elem *l;
+	u32 hash, key_size;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
+
+	key_size = map->key_size;
+
+	hash = htab_map_hash(key, key_size, htab->hashrnd);
+
+	head = select_bucket(htab, hash);
+
+	l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
+
+	return l;
+}
+
+static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct htab_elem *l = __htab_map_lookup_elem(map, key);
+
+	if (l)
+		return l->key + round_up(map->key_size, 8);
+
+	return NULL;
+}
+
+/* inline bpf_map_lookup_elem() call.
+ * Instead of:
+ * bpf_prog
+ *   bpf_map_lookup_elem
+ *     map->ops->map_lookup_elem
+ *       htab_map_lookup_elem
+ *         __htab_map_lookup_elem
+ * do:
+ * bpf_prog
+ *   __htab_map_lookup_elem
+ */
+static int htab_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
+{
+	struct bpf_insn *insn = insn_buf;
+	const int ret = BPF_REG_0;
+
+	BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
+		     (void *(*)(struct bpf_map *map, void *key))NULL));
+	*insn++ = BPF_EMIT_CALL(BPF_CAST_CALL(__htab_map_lookup_elem));
+	*insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
+	*insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
+				offsetof(struct htab_elem, key) +
+				round_up(map->key_size, 8));
+	return insn - insn_buf;
+}
+
+static __always_inline void *__htab_lru_map_lookup_elem(struct bpf_map *map,
+							void *key, const bool mark)
+{
+	struct htab_elem *l = __htab_map_lookup_elem(map, key);
+
+	if (l) {
+		if (mark)
+			bpf_lru_node_set_ref(&l->lru_node);
+		return l->key + round_up(map->key_size, 8);
+	}
+
+	return NULL;
+}
+
+static void *htab_lru_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	return __htab_lru_map_lookup_elem(map, key, true);
+}
+
+static void *htab_lru_map_lookup_elem_sys(struct bpf_map *map, void *key)
+{
+	return __htab_lru_map_lookup_elem(map, key, false);
+}
+
+static int htab_lru_map_gen_lookup(struct bpf_map *map,
+				   struct bpf_insn *insn_buf)
+{
+	struct bpf_insn *insn = insn_buf;
+	const int ret = BPF_REG_0;
+	const int ref_reg = BPF_REG_1;
+
+	BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
+		     (void *(*)(struct bpf_map *map, void *key))NULL));
+	*insn++ = BPF_EMIT_CALL(BPF_CAST_CALL(__htab_map_lookup_elem));
+	*insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 4);
+	*insn++ = BPF_LDX_MEM(BPF_B, ref_reg, ret,
+			      offsetof(struct htab_elem, lru_node) +
+			      offsetof(struct bpf_lru_node, ref));
+	*insn++ = BPF_JMP_IMM(BPF_JNE, ref_reg, 0, 1);
+	*insn++ = BPF_ST_MEM(BPF_B, ret,
+			     offsetof(struct htab_elem, lru_node) +
+			     offsetof(struct bpf_lru_node, ref),
+			     1);
+	*insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
+				offsetof(struct htab_elem, key) +
+				round_up(map->key_size, 8));
+	return insn - insn_buf;
+}
+
+/* It is called from the bpf_lru_list when the LRU needs to delete
+ * older elements from the htab.
+ */
+static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node)
+{
+	struct bpf_htab *htab = (struct bpf_htab *)arg;
+	struct htab_elem *l = NULL, *tgt_l;
+	struct hlist_nulls_head *head;
+	struct hlist_nulls_node *n;
+	unsigned long flags;
+	struct bucket *b;
+
+	tgt_l = container_of(node, struct htab_elem, lru_node);
+	b = __select_bucket(htab, tgt_l->hash);
+	head = &b->head;
+
+	flags = htab_lock_bucket(htab, b);
+
+	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
+		if (l == tgt_l) {
+			hlist_nulls_del_rcu(&l->hash_node);
+			break;
+		}
+
+	htab_unlock_bucket(htab, b, flags);
+
+	return l == tgt_l;
+}
+
+/* Called from syscall */
+static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct hlist_nulls_head *head;
+	struct htab_elem *l, *next_l;
+	u32 hash, key_size;
+	int i = 0;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	key_size = map->key_size;
+
+	if (!key)
+		goto find_first_elem;
+
+	hash = htab_map_hash(key, key_size, htab->hashrnd);
+
+	head = select_bucket(htab, hash);
+
+	/* lookup the key */
+	l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
+
+	if (!l)
+		goto find_first_elem;
+
+	/* key was found, get next key in the same bucket */
+	next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_next_rcu(&l->hash_node)),
+				  struct htab_elem, hash_node);
+
+	if (next_l) {
+		/* if next elem in this hash list is non-zero, just return it */
+		memcpy(next_key, next_l->key, key_size);
+		return 0;
+	}
+
+	/* no more elements in this hash list, go to the next bucket */
+	i = hash & (htab->n_buckets - 1);
+	i++;
+
+find_first_elem:
+	/* iterate over buckets */
+	for (; i < htab->n_buckets; i++) {
+		head = select_bucket(htab, i);
+
+		/* pick first element in the bucket */
+		next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_first_rcu(head)),
+					  struct htab_elem, hash_node);
+		if (next_l) {
+			/* if it's not empty, just return it */
+			memcpy(next_key, next_l->key, key_size);
+			return 0;
+		}
+	}
+
+	/* iterated over all buckets and all elements */
+	return -ENOENT;
+}
+
+static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l)
+{
+	if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH)
+		free_percpu(htab_elem_get_ptr(l, htab->map.key_size));
+	kfree(l);
+}
+
+static void htab_elem_free_rcu(struct rcu_head *head)
+{
+	struct htab_elem *l = container_of(head, struct htab_elem, rcu);
+	struct bpf_htab *htab = l->htab;
+
+	htab_elem_free(htab, l);
+}
+
+static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l)
+{
+	struct bpf_map *map = &htab->map;
+	void *ptr;
+
+	if (map->ops->map_fd_put_ptr) {
+		ptr = fd_htab_map_get_ptr(map, l);
+		map->ops->map_fd_put_ptr(ptr);
+	}
+}
+
+static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
+{
+	htab_put_fd_value(htab, l);
+
+	if (htab_is_prealloc(htab)) {
+		__pcpu_freelist_push(&htab->freelist, &l->fnode);
+	} else {
+		atomic_dec(&htab->count);
+		l->htab = htab;
+		call_rcu(&l->rcu, htab_elem_free_rcu);
+	}
+}
+
+static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr,
+			    void *value, bool onallcpus)
+{
+	if (!onallcpus) {
+		/* copy true value_size bytes */
+		memcpy(this_cpu_ptr(pptr), value, htab->map.value_size);
+	} else {
+		u32 size = round_up(htab->map.value_size, 8);
+		int off = 0, cpu;
+
+		for_each_possible_cpu(cpu) {
+			bpf_long_memcpy(per_cpu_ptr(pptr, cpu),
+					value + off, size);
+			off += size;
+		}
+	}
+}
+
+static void pcpu_init_value(struct bpf_htab *htab, void __percpu *pptr,
+			    void *value, bool onallcpus)
+{
+	/* When using prealloc and not setting the initial value on all cpus,
+	 * zero-fill element values for other cpus (just as what happens when
+	 * not using prealloc). Otherwise, bpf program has no way to ensure
+	 * known initial values for cpus other than current one
+	 * (onallcpus=false always when coming from bpf prog).
+	 */
+	if (htab_is_prealloc(htab) && !onallcpus) {
+		u32 size = round_up(htab->map.value_size, 8);
+		int current_cpu = raw_smp_processor_id();
+		int cpu;
+
+		for_each_possible_cpu(cpu) {
+			if (cpu == current_cpu)
+				bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value,
+						size);
+			else
+				memset(per_cpu_ptr(pptr, cpu), 0, size);
+		}
+	} else {
+		pcpu_copy_value(htab, pptr, value, onallcpus);
+	}
+}
+
+static bool fd_htab_map_needs_adjust(const struct bpf_htab *htab)
+{
+	return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS &&
+	       BITS_PER_LONG == 64;
+}
+
+static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
+					 void *value, u32 key_size, u32 hash,
+					 bool percpu, bool onallcpus,
+					 struct htab_elem *old_elem)
+{
+	u32 size = htab->map.value_size;
+	bool prealloc = htab_is_prealloc(htab);
+	struct htab_elem *l_new, **pl_new;
+	void __percpu *pptr;
+
+	if (prealloc) {
+		if (old_elem) {
+			/* if we're updating the existing element,
+			 * use per-cpu extra elems to avoid freelist_pop/push
+			 */
+			pl_new = this_cpu_ptr(htab->extra_elems);
+			l_new = *pl_new;
+			htab_put_fd_value(htab, old_elem);
+			*pl_new = old_elem;
+		} else {
+			struct pcpu_freelist_node *l;
+
+			l = __pcpu_freelist_pop(&htab->freelist);
+			if (!l)
+				return ERR_PTR(-E2BIG);
+			l_new = container_of(l, struct htab_elem, fnode);
+		}
+	} else {
+		if (atomic_inc_return(&htab->count) > htab->map.max_entries)
+			if (!old_elem) {
+				/* when map is full and update() is replacing
+				 * old element, it's ok to allocate, since
+				 * old element will be freed immediately.
+				 * Otherwise return an error
+				 */
+				l_new = ERR_PTR(-E2BIG);
+				goto dec_count;
+			}
+		l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
+				     htab->map.numa_node);
+		if (!l_new) {
+			l_new = ERR_PTR(-ENOMEM);
+			goto dec_count;
+		}
+		check_and_init_map_lock(&htab->map,
+					l_new->key + round_up(key_size, 8));
+	}
+
+	memcpy(l_new->key, key, key_size);
+	if (percpu) {
+		size = round_up(size, 8);
+		if (prealloc) {
+			pptr = htab_elem_get_ptr(l_new, key_size);
+		} else {
+			/* alloc_percpu zero-fills */
+			pptr = __alloc_percpu_gfp(size, 8,
+						  GFP_ATOMIC | __GFP_NOWARN);
+			if (!pptr) {
+				kfree(l_new);
+				l_new = ERR_PTR(-ENOMEM);
+				goto dec_count;
+			}
+		}
+
+		pcpu_init_value(htab, pptr, value, onallcpus);
+
+		if (!prealloc)
+			htab_elem_set_ptr(l_new, key_size, pptr);
+	} else if (fd_htab_map_needs_adjust(htab)) {
+		size = round_up(size, 8);
+		memcpy(l_new->key + round_up(key_size, 8), value, size);
+	} else {
+		copy_map_value(&htab->map,
+			       l_new->key + round_up(key_size, 8),
+			       value);
+	}
+
+	l_new->hash = hash;
+	return l_new;
+dec_count:
+	atomic_dec(&htab->count);
+	return l_new;
+}
+
+static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old,
+		       u64 map_flags)
+{
+	if (l_old && (map_flags & ~BPF_F_LOCK) == BPF_NOEXIST)
+		/* elem already exists */
+		return -EEXIST;
+
+	if (!l_old && (map_flags & ~BPF_F_LOCK) == BPF_EXIST)
+		/* elem doesn't exist, cannot update it */
+		return -ENOENT;
+
+	return 0;
+}
+
+/* Called from syscall or from eBPF program */
+static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
+				u64 map_flags)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct htab_elem *l_new = NULL, *l_old;
+	struct hlist_nulls_head *head;
+	unsigned long flags;
+	struct bucket *b;
+	u32 key_size, hash;
+	int ret;
+
+	if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST))
+		/* unknown flags */
+		return -EINVAL;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
+
+	key_size = map->key_size;
+
+	hash = htab_map_hash(key, key_size, htab->hashrnd);
+
+	b = __select_bucket(htab, hash);
+	head = &b->head;
+
+	if (unlikely(map_flags & BPF_F_LOCK)) {
+		if (unlikely(!map_value_has_spin_lock(map)))
+			return -EINVAL;
+		/* find an element without taking the bucket lock */
+		l_old = lookup_nulls_elem_raw(head, hash, key, key_size,
+					      htab->n_buckets);
+		ret = check_flags(htab, l_old, map_flags);
+		if (ret)
+			return ret;
+		if (l_old) {
+			/* grab the element lock and update value in place */
+			copy_map_value_locked(map,
+					      l_old->key + round_up(key_size, 8),
+					      value, false);
+			return 0;
+		}
+		/* fall through, grab the bucket lock and lookup again.
+		 * 99.9% chance that the element won't be found,
+		 * but second lookup under lock has to be done.
+		 */
+	}
+
+	flags = htab_lock_bucket(htab, b);
+
+	l_old = lookup_elem_raw(head, hash, key, key_size);
+
+	ret = check_flags(htab, l_old, map_flags);
+	if (ret)
+		goto err;
+
+	if (unlikely(l_old && (map_flags & BPF_F_LOCK))) {
+		/* first lookup without the bucket lock didn't find the element,
+		 * but second lookup with the bucket lock found it.
+		 * This case is highly unlikely, but has to be dealt with:
+		 * grab the element lock in addition to the bucket lock
+		 * and update element in place
+		 */
+		copy_map_value_locked(map,
+				      l_old->key + round_up(key_size, 8),
+				      value, false);
+		ret = 0;
+		goto err;
+	}
+
+	l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false,
+				l_old);
+	if (IS_ERR(l_new)) {
+		/* all pre-allocated elements are in use or memory exhausted */
+		ret = PTR_ERR(l_new);
+		goto err;
+	}
+
+	/* add new element to the head of the list, so that
+	 * concurrent search will find it before old elem
+	 */
+	hlist_nulls_add_head_rcu(&l_new->hash_node, head);
+	if (l_old) {
+		hlist_nulls_del_rcu(&l_old->hash_node);
+		if (!htab_is_prealloc(htab))
+			free_htab_elem(htab, l_old);
+	}
+	ret = 0;
+err:
+	htab_unlock_bucket(htab, b, flags);
+	return ret;
+}
+
+static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value,
+				    u64 map_flags)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct htab_elem *l_new, *l_old = NULL;
+	struct hlist_nulls_head *head;
+	unsigned long flags;
+	struct bucket *b;
+	u32 key_size, hash;
+	int ret;
+
+	if (unlikely(map_flags > BPF_EXIST))
+		/* unknown flags */
+		return -EINVAL;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
+
+	key_size = map->key_size;
+
+	hash = htab_map_hash(key, key_size, htab->hashrnd);
+
+	b = __select_bucket(htab, hash);
+	head = &b->head;
+
+	/* For LRU, we need to alloc before taking bucket's
+	 * spinlock because getting free nodes from LRU may need
+	 * to remove older elements from htab and this removal
+	 * operation will need a bucket lock.
+	 */
+	l_new = prealloc_lru_pop(htab, key, hash);
+	if (!l_new)
+		return -ENOMEM;
+	memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size);
+
+	flags = htab_lock_bucket(htab, b);
+
+	l_old = lookup_elem_raw(head, hash, key, key_size);
+
+	ret = check_flags(htab, l_old, map_flags);
+	if (ret)
+		goto err;
+
+	/* add new element to the head of the list, so that
+	 * concurrent search will find it before old elem
+	 */
+	hlist_nulls_add_head_rcu(&l_new->hash_node, head);
+	if (l_old) {
+		bpf_lru_node_set_ref(&l_new->lru_node);
+		hlist_nulls_del_rcu(&l_old->hash_node);
+	}
+	ret = 0;
+
+err:
+	htab_unlock_bucket(htab, b, flags);
+
+	if (ret)
+		bpf_lru_push_free(&htab->lru, &l_new->lru_node);
+	else if (l_old)
+		bpf_lru_push_free(&htab->lru, &l_old->lru_node);
+
+	return ret;
+}
+
+static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
+					 void *value, u64 map_flags,
+					 bool onallcpus)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct htab_elem *l_new = NULL, *l_old;
+	struct hlist_nulls_head *head;
+	unsigned long flags;
+	struct bucket *b;
+	u32 key_size, hash;
+	int ret;
+
+	if (unlikely(map_flags > BPF_EXIST))
+		/* unknown flags */
+		return -EINVAL;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	key_size = map->key_size;
+
+	hash = htab_map_hash(key, key_size, htab->hashrnd);
+
+	b = __select_bucket(htab, hash);
+	head = &b->head;
+
+	flags = htab_lock_bucket(htab, b);
+
+	l_old = lookup_elem_raw(head, hash, key, key_size);
+
+	ret = check_flags(htab, l_old, map_flags);
+	if (ret)
+		goto err;
+
+	if (l_old) {
+		/* per-cpu hash map can update value in-place */
+		pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
+				value, onallcpus);
+	} else {
+		l_new = alloc_htab_elem(htab, key, value, key_size,
+					hash, true, onallcpus, NULL);
+		if (IS_ERR(l_new)) {
+			ret = PTR_ERR(l_new);
+			goto err;
+		}
+		hlist_nulls_add_head_rcu(&l_new->hash_node, head);
+	}
+	ret = 0;
+err:
+	htab_unlock_bucket(htab, b, flags);
+	return ret;
+}
+
+static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
+					     void *value, u64 map_flags,
+					     bool onallcpus)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct htab_elem *l_new = NULL, *l_old;
+	struct hlist_nulls_head *head;
+	unsigned long flags;
+	struct bucket *b;
+	u32 key_size, hash;
+	int ret;
+
+	if (unlikely(map_flags > BPF_EXIST))
+		/* unknown flags */
+		return -EINVAL;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	key_size = map->key_size;
+
+	hash = htab_map_hash(key, key_size, htab->hashrnd);
+
+	b = __select_bucket(htab, hash);
+	head = &b->head;
+
+	/* For LRU, we need to alloc before taking bucket's
+	 * spinlock because LRU's elem alloc may need
+	 * to remove older elem from htab and this removal
+	 * operation will need a bucket lock.
+	 */
+	if (map_flags != BPF_EXIST) {
+		l_new = prealloc_lru_pop(htab, key, hash);
+		if (!l_new)
+			return -ENOMEM;
+	}
+
+	flags = htab_lock_bucket(htab, b);
+
+	l_old = lookup_elem_raw(head, hash, key, key_size);
+
+	ret = check_flags(htab, l_old, map_flags);
+	if (ret)
+		goto err;
+
+	if (l_old) {
+		bpf_lru_node_set_ref(&l_old->lru_node);
+
+		/* per-cpu hash map can update value in-place */
+		pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
+				value, onallcpus);
+	} else {
+		pcpu_init_value(htab, htab_elem_get_ptr(l_new, key_size),
+				value, onallcpus);
+		hlist_nulls_add_head_rcu(&l_new->hash_node, head);
+		l_new = NULL;
+	}
+	ret = 0;
+err:
+	htab_unlock_bucket(htab, b, flags);
+	if (l_new)
+		bpf_lru_push_free(&htab->lru, &l_new->lru_node);
+	return ret;
+}
+
+static int htab_percpu_map_update_elem(struct bpf_map *map, void *key,
+				       void *value, u64 map_flags)
+{
+	return __htab_percpu_map_update_elem(map, key, value, map_flags, false);
+}
+
+static int htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
+					   void *value, u64 map_flags)
+{
+	return __htab_lru_percpu_map_update_elem(map, key, value, map_flags,
+						 false);
+}
+
+/* Called from syscall or from eBPF program */
+static int htab_map_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct hlist_nulls_head *head;
+	struct bucket *b;
+	struct htab_elem *l;
+	unsigned long flags;
+	u32 hash, key_size;
+	int ret = -ENOENT;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
+
+	key_size = map->key_size;
+
+	hash = htab_map_hash(key, key_size, htab->hashrnd);
+	b = __select_bucket(htab, hash);
+	head = &b->head;
+
+	flags = htab_lock_bucket(htab, b);
+
+	l = lookup_elem_raw(head, hash, key, key_size);
+
+	if (l) {
+		hlist_nulls_del_rcu(&l->hash_node);
+		free_htab_elem(htab, l);
+		ret = 0;
+	}
+
+	htab_unlock_bucket(htab, b, flags);
+	return ret;
+}
+
+static int htab_lru_map_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct hlist_nulls_head *head;
+	struct bucket *b;
+	struct htab_elem *l;
+	unsigned long flags;
+	u32 hash, key_size;
+	int ret = -ENOENT;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held());
+
+	key_size = map->key_size;
+
+	hash = htab_map_hash(key, key_size, htab->hashrnd);
+	b = __select_bucket(htab, hash);
+	head = &b->head;
+
+	flags = htab_lock_bucket(htab, b);
+
+	l = lookup_elem_raw(head, hash, key, key_size);
+
+	if (l) {
+		hlist_nulls_del_rcu(&l->hash_node);
+		ret = 0;
+	}
+
+	htab_unlock_bucket(htab, b, flags);
+	if (l)
+		bpf_lru_push_free(&htab->lru, &l->lru_node);
+	return ret;
+}
+
+static void delete_all_elements(struct bpf_htab *htab)
+{
+	int i;
+
+	for (i = 0; i < htab->n_buckets; i++) {
+		struct hlist_nulls_head *head = select_bucket(htab, i);
+		struct hlist_nulls_node *n;
+		struct htab_elem *l;
+
+		hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
+			hlist_nulls_del_rcu(&l->hash_node);
+			htab_elem_free(htab, l);
+		}
+	}
+}
+
+/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
+static void htab_map_free(struct bpf_map *map)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+
+	/* bpf_free_used_maps() or close(map_fd) will trigger this map_free callback.
+	 * bpf_free_used_maps() is called after bpf prog is no longer executing.
+	 * There is no need to synchronize_rcu() here to protect map elements.
+	 */
+
+	/* some of free_htab_elem() callbacks for elements of this map may
+	 * not have executed. Wait for them.
+	 */
+	rcu_barrier();
+	if (!htab_is_prealloc(htab))
+		delete_all_elements(htab);
+	else
+		prealloc_destroy(htab);
+
+	free_percpu(htab->extra_elems);
+	bpf_map_area_free(htab->buckets);
+	kfree(htab);
+}
+
+static void htab_map_seq_show_elem(struct bpf_map *map, void *key,
+				   struct seq_file *m)
+{
+	void *value;
+
+	rcu_read_lock();
+
+	value = htab_map_lookup_elem(map, key);
+	if (!value) {
+		rcu_read_unlock();
+		return;
+	}
+
+	btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
+	seq_puts(m, ": ");
+	btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
+	seq_puts(m, "\n");
+
+	rcu_read_unlock();
+}
+
+static int
+__htab_map_lookup_and_delete_batch(struct bpf_map *map,
+				   const union bpf_attr *attr,
+				   union bpf_attr __user *uattr,
+				   bool do_delete, bool is_lru_map,
+				   bool is_percpu)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	u32 bucket_cnt, total, key_size, value_size, roundup_key_size;
+	void *keys = NULL, *values = NULL, *value, *dst_key, *dst_val;
+	void __user *uvalues = u64_to_user_ptr(attr->batch.values);
+	void __user *ukeys = u64_to_user_ptr(attr->batch.keys);
+	void *ubatch = u64_to_user_ptr(attr->batch.in_batch);
+	u32 batch, max_count, size, bucket_size;
+	struct htab_elem *node_to_free = NULL;
+	u64 elem_map_flags, map_flags;
+	struct hlist_nulls_head *head;
+	struct hlist_nulls_node *n;
+	unsigned long flags = 0;
+	bool locked = false;
+	struct htab_elem *l;
+	struct bucket *b;
+	int ret = 0;
+
+	elem_map_flags = attr->batch.elem_flags;
+	if ((elem_map_flags & ~BPF_F_LOCK) ||
+	    ((elem_map_flags & BPF_F_LOCK) && !map_value_has_spin_lock(map)))
+		return -EINVAL;
+
+	map_flags = attr->batch.flags;
+	if (map_flags)
+		return -EINVAL;
+
+	max_count = attr->batch.count;
+	if (!max_count)
+		return 0;
+
+	if (put_user(0, &uattr->batch.count))
+		return -EFAULT;
+
+	batch = 0;
+	if (ubatch && copy_from_user(&batch, ubatch, sizeof(batch)))
+		return -EFAULT;
+
+	if (batch >= htab->n_buckets)
+		return -ENOENT;
+
+	key_size = htab->map.key_size;
+	roundup_key_size = round_up(htab->map.key_size, 8);
+	value_size = htab->map.value_size;
+	size = round_up(value_size, 8);
+	if (is_percpu)
+		value_size = size * num_possible_cpus();
+	total = 0;
+	/* while experimenting with hash tables with sizes ranging from 10 to
+	 * 1000, it was observed that a bucket can have upto 5 entries.
+	 */
+	bucket_size = 5;
+
+alloc:
+	/* We cannot do copy_from_user or copy_to_user inside
+	 * the rcu_read_lock. Allocate enough space here.
+	 */
+	keys = kvmalloc_array(key_size, bucket_size, GFP_USER | __GFP_NOWARN);
+	values = kvmalloc_array(value_size, bucket_size, GFP_USER | __GFP_NOWARN);
+	if (!keys || !values) {
+		ret = -ENOMEM;
+		goto after_loop;
+	}
+
+again:
+	bpf_disable_instrumentation();
+	rcu_read_lock();
+again_nocopy:
+	dst_key = keys;
+	dst_val = values;
+	b = &htab->buckets[batch];
+	head = &b->head;
+	/* do not grab the lock unless need it (bucket_cnt > 0). */
+	if (locked)
+		flags = htab_lock_bucket(htab, b);
+
+	bucket_cnt = 0;
+	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
+		bucket_cnt++;
+
+	if (bucket_cnt && !locked) {
+		locked = true;
+		goto again_nocopy;
+	}
+
+	if (bucket_cnt > (max_count - total)) {
+		if (total == 0)
+			ret = -ENOSPC;
+		/* Note that since bucket_cnt > 0 here, it is implicit
+		 * that the locked was grabbed, so release it.
+		 */
+		htab_unlock_bucket(htab, b, flags);
+		rcu_read_unlock();
+		bpf_enable_instrumentation();
+		goto after_loop;
+	}
+
+	if (bucket_cnt > bucket_size) {
+		bucket_size = bucket_cnt;
+		/* Note that since bucket_cnt > 0 here, it is implicit
+		 * that the locked was grabbed, so release it.
+		 */
+		htab_unlock_bucket(htab, b, flags);
+		rcu_read_unlock();
+		bpf_enable_instrumentation();
+		kvfree(keys);
+		kvfree(values);
+		goto alloc;
+	}
+
+	/* Next block is only safe to run if you have grabbed the lock */
+	if (!locked)
+		goto next_batch;
+
+	hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
+		memcpy(dst_key, l->key, key_size);
+
+		if (is_percpu) {
+			int off = 0, cpu;
+			void __percpu *pptr;
+
+			pptr = htab_elem_get_ptr(l, map->key_size);
+			for_each_possible_cpu(cpu) {
+				bpf_long_memcpy(dst_val + off,
+						per_cpu_ptr(pptr, cpu), size);
+				off += size;
+			}
+		} else {
+			value = l->key + roundup_key_size;
+			if (elem_map_flags & BPF_F_LOCK)
+				copy_map_value_locked(map, dst_val, value,
+						      true);
+			else
+				copy_map_value(map, dst_val, value);
+			check_and_init_map_lock(map, dst_val);
+		}
+		if (do_delete) {
+			hlist_nulls_del_rcu(&l->hash_node);
+
+			/* bpf_lru_push_free() will acquire lru_lock, which
+			 * may cause deadlock. See comments in function
+			 * prealloc_lru_pop(). Let us do bpf_lru_push_free()
+			 * after releasing the bucket lock.
+			 */
+			if (is_lru_map) {
+				l->batch_flink = node_to_free;
+				node_to_free = l;
+			} else {
+				free_htab_elem(htab, l);
+			}
+		}
+		dst_key += key_size;
+		dst_val += value_size;
+	}
+
+	htab_unlock_bucket(htab, b, flags);
+	locked = false;
+
+	while (node_to_free) {
+		l = node_to_free;
+		node_to_free = node_to_free->batch_flink;
+		bpf_lru_push_free(&htab->lru, &l->lru_node);
+	}
+
+next_batch:
+	/* If we are not copying data, we can go to next bucket and avoid
+	 * unlocking the rcu.
+	 */
+	if (!bucket_cnt && (batch + 1 < htab->n_buckets)) {
+		batch++;
+		goto again_nocopy;
+	}
+
+	rcu_read_unlock();
+	bpf_enable_instrumentation();
+	if (bucket_cnt && (copy_to_user(ukeys + total * key_size, keys,
+	    key_size * bucket_cnt) ||
+	    copy_to_user(uvalues + total * value_size, values,
+	    value_size * bucket_cnt))) {
+		ret = -EFAULT;
+		goto after_loop;
+	}
+
+	total += bucket_cnt;
+	batch++;
+	if (batch >= htab->n_buckets) {
+		ret = -ENOENT;
+		goto after_loop;
+	}
+	goto again;
+
+after_loop:
+	if (ret == -EFAULT)
+		goto out;
+
+	/* copy # of entries and next batch */
+	ubatch = u64_to_user_ptr(attr->batch.out_batch);
+	if (copy_to_user(ubatch, &batch, sizeof(batch)) ||
+	    put_user(total, &uattr->batch.count))
+		ret = -EFAULT;
+
+out:
+	kvfree(keys);
+	kvfree(values);
+	return ret;
+}
+
+static int
+htab_percpu_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
+			     union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
+						  false, true);
+}
+
+static int
+htab_percpu_map_lookup_and_delete_batch(struct bpf_map *map,
+					const union bpf_attr *attr,
+					union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
+						  false, true);
+}
+
+static int
+htab_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
+		      union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
+						  false, false);
+}
+
+static int
+htab_map_lookup_and_delete_batch(struct bpf_map *map,
+				 const union bpf_attr *attr,
+				 union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
+						  false, false);
+}
+
+static int
+htab_lru_percpu_map_lookup_batch(struct bpf_map *map,
+				 const union bpf_attr *attr,
+				 union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
+						  true, true);
+}
+
+static int
+htab_lru_percpu_map_lookup_and_delete_batch(struct bpf_map *map,
+					    const union bpf_attr *attr,
+					    union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
+						  true, true);
+}
+
+static int
+htab_lru_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
+			  union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
+						  true, false);
+}
+
+static int
+htab_lru_map_lookup_and_delete_batch(struct bpf_map *map,
+				     const union bpf_attr *attr,
+				     union bpf_attr __user *uattr)
+{
+	return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
+						  true, false);
+}
+
+struct bpf_iter_seq_hash_map_info {
+	struct bpf_map *map;
+	struct bpf_htab *htab;
+	void *percpu_value_buf; // non-zero means percpu hash
+	u32 bucket_id;
+	u32 skip_elems;
+};
+
+static struct htab_elem *
+bpf_hash_map_seq_find_next(struct bpf_iter_seq_hash_map_info *info,
+			   struct htab_elem *prev_elem)
+{
+	const struct bpf_htab *htab = info->htab;
+	u32 skip_elems = info->skip_elems;
+	u32 bucket_id = info->bucket_id;
+	struct hlist_nulls_head *head;
+	struct hlist_nulls_node *n;
+	struct htab_elem *elem;
+	struct bucket *b;
+	u32 i, count;
+
+	if (bucket_id >= htab->n_buckets)
+		return NULL;
+
+	/* try to find next elem in the same bucket */
+	if (prev_elem) {
+		/* no update/deletion on this bucket, prev_elem should be still valid
+		 * and we won't skip elements.
+		 */
+		n = rcu_dereference_raw(hlist_nulls_next_rcu(&prev_elem->hash_node));
+		elem = hlist_nulls_entry_safe(n, struct htab_elem, hash_node);
+		if (elem)
+			return elem;
+
+		/* not found, unlock and go to the next bucket */
+		b = &htab->buckets[bucket_id++];
+		rcu_read_unlock();
+		skip_elems = 0;
+	}
+
+	for (i = bucket_id; i < htab->n_buckets; i++) {
+		b = &htab->buckets[i];
+		rcu_read_lock();
+
+		count = 0;
+		head = &b->head;
+		hlist_nulls_for_each_entry_rcu(elem, n, head, hash_node) {
+			if (count >= skip_elems) {
+				info->bucket_id = i;
+				info->skip_elems = count;
+				return elem;
+			}
+			count++;
+		}
+
+		rcu_read_unlock();
+		skip_elems = 0;
+	}
+
+	info->bucket_id = i;
+	info->skip_elems = 0;
+	return NULL;
+}
+
+static void *bpf_hash_map_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_hash_map_info *info = seq->private;
+	struct htab_elem *elem;
+
+	elem = bpf_hash_map_seq_find_next(info, NULL);
+	if (!elem)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	return elem;
+}
+
+static void *bpf_hash_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_hash_map_info *info = seq->private;
+
+	++*pos;
+	++info->skip_elems;
+	return bpf_hash_map_seq_find_next(info, v);
+}
+
+static int __bpf_hash_map_seq_show(struct seq_file *seq, struct htab_elem *elem)
+{
+	struct bpf_iter_seq_hash_map_info *info = seq->private;
+	u32 roundup_key_size, roundup_value_size;
+	struct bpf_iter__bpf_map_elem ctx = {};
+	struct bpf_map *map = info->map;
+	struct bpf_iter_meta meta;
+	int ret = 0, off = 0, cpu;
+	struct bpf_prog *prog;
+	void __percpu *pptr;
+
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, elem == NULL);
+	if (prog) {
+		ctx.meta = &meta;
+		ctx.map = info->map;
+		if (elem) {
+			roundup_key_size = round_up(map->key_size, 8);
+			ctx.key = elem->key;
+			if (!info->percpu_value_buf) {
+				ctx.value = elem->key + roundup_key_size;
+			} else {
+				roundup_value_size = round_up(map->value_size, 8);
+				pptr = htab_elem_get_ptr(elem, map->key_size);
+				for_each_possible_cpu(cpu) {
+					bpf_long_memcpy(info->percpu_value_buf + off,
+							per_cpu_ptr(pptr, cpu),
+							roundup_value_size);
+					off += roundup_value_size;
+				}
+				ctx.value = info->percpu_value_buf;
+			}
+		}
+		ret = bpf_iter_run_prog(prog, &ctx);
+	}
+
+	return ret;
+}
+
+static int bpf_hash_map_seq_show(struct seq_file *seq, void *v)
+{
+	return __bpf_hash_map_seq_show(seq, v);
+}
+
+static void bpf_hash_map_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__bpf_hash_map_seq_show(seq, NULL);
+	else
+		rcu_read_unlock();
+}
+
+static int bpf_iter_init_hash_map(void *priv_data,
+				  struct bpf_iter_aux_info *aux)
+{
+	struct bpf_iter_seq_hash_map_info *seq_info = priv_data;
+	struct bpf_map *map = aux->map;
+	void *value_buf;
+	u32 buf_size;
+
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+		buf_size = round_up(map->value_size, 8) * num_possible_cpus();
+		value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
+		if (!value_buf)
+			return -ENOMEM;
+
+		seq_info->percpu_value_buf = value_buf;
+	}
+
+	bpf_map_inc_with_uref(map);
+	seq_info->map = map;
+	seq_info->htab = container_of(map, struct bpf_htab, map);
+	return 0;
+}
+
+static void bpf_iter_fini_hash_map(void *priv_data)
+{
+	struct bpf_iter_seq_hash_map_info *seq_info = priv_data;
+
+	bpf_map_put_with_uref(seq_info->map);
+	kfree(seq_info->percpu_value_buf);
+}
+
+static const struct seq_operations bpf_hash_map_seq_ops = {
+	.start	= bpf_hash_map_seq_start,
+	.next	= bpf_hash_map_seq_next,
+	.stop	= bpf_hash_map_seq_stop,
+	.show	= bpf_hash_map_seq_show,
+};
+
+static const struct bpf_iter_seq_info iter_seq_info = {
+	.seq_ops		= &bpf_hash_map_seq_ops,
+	.init_seq_private	= bpf_iter_init_hash_map,
+	.fini_seq_private	= bpf_iter_fini_hash_map,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_hash_map_info),
+};
+
+static int htab_map_btf_id;
+const struct bpf_map_ops htab_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = htab_map_alloc_check,
+	.map_alloc = htab_map_alloc,
+	.map_free = htab_map_free,
+	.map_get_next_key = htab_map_get_next_key,
+	.map_lookup_elem = htab_map_lookup_elem,
+	.map_update_elem = htab_map_update_elem,
+	.map_delete_elem = htab_map_delete_elem,
+	.map_gen_lookup = htab_map_gen_lookup,
+	.map_seq_show_elem = htab_map_seq_show_elem,
+	BATCH_OPS(htab),
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
+};
+
+static int htab_lru_map_btf_id;
+const struct bpf_map_ops htab_lru_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = htab_map_alloc_check,
+	.map_alloc = htab_map_alloc,
+	.map_free = htab_map_free,
+	.map_get_next_key = htab_map_get_next_key,
+	.map_lookup_elem = htab_lru_map_lookup_elem,
+	.map_lookup_elem_sys_only = htab_lru_map_lookup_elem_sys,
+	.map_update_elem = htab_lru_map_update_elem,
+	.map_delete_elem = htab_lru_map_delete_elem,
+	.map_gen_lookup = htab_lru_map_gen_lookup,
+	.map_seq_show_elem = htab_map_seq_show_elem,
+	BATCH_OPS(htab_lru),
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_lru_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
+};
+
+/* Called from eBPF program */
+static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct htab_elem *l = __htab_map_lookup_elem(map, key);
+
+	if (l)
+		return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
+	else
+		return NULL;
+}
+
+static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct htab_elem *l = __htab_map_lookup_elem(map, key);
+
+	if (l) {
+		bpf_lru_node_set_ref(&l->lru_node);
+		return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
+	}
+
+	return NULL;
+}
+
+int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
+{
+	struct htab_elem *l;
+	void __percpu *pptr;
+	int ret = -ENOENT;
+	int cpu, off = 0;
+	u32 size;
+
+	/* per_cpu areas are zero-filled and bpf programs can only
+	 * access 'value_size' of them, so copying rounded areas
+	 * will not leak any kernel data
+	 */
+	size = round_up(map->value_size, 8);
+	rcu_read_lock();
+	l = __htab_map_lookup_elem(map, key);
+	if (!l)
+		goto out;
+	/* We do not mark LRU map element here in order to not mess up
+	 * eviction heuristics when user space does a map walk.
+	 */
+	pptr = htab_elem_get_ptr(l, map->key_size);
+	for_each_possible_cpu(cpu) {
+		bpf_long_memcpy(value + off,
+				per_cpu_ptr(pptr, cpu), size);
+		off += size;
+	}
+	ret = 0;
+out:
+	rcu_read_unlock();
+	return ret;
+}
+
+int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
+			   u64 map_flags)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	int ret;
+
+	rcu_read_lock();
+	if (htab_is_lru(htab))
+		ret = __htab_lru_percpu_map_update_elem(map, key, value,
+							map_flags, true);
+	else
+		ret = __htab_percpu_map_update_elem(map, key, value, map_flags,
+						    true);
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static void htab_percpu_map_seq_show_elem(struct bpf_map *map, void *key,
+					  struct seq_file *m)
+{
+	struct htab_elem *l;
+	void __percpu *pptr;
+	int cpu;
+
+	rcu_read_lock();
+
+	l = __htab_map_lookup_elem(map, key);
+	if (!l) {
+		rcu_read_unlock();
+		return;
+	}
+
+	btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
+	seq_puts(m, ": {\n");
+	pptr = htab_elem_get_ptr(l, map->key_size);
+	for_each_possible_cpu(cpu) {
+		seq_printf(m, "\tcpu%d: ", cpu);
+		btf_type_seq_show(map->btf, map->btf_value_type_id,
+				  per_cpu_ptr(pptr, cpu), m);
+		seq_puts(m, "\n");
+	}
+	seq_puts(m, "}\n");
+
+	rcu_read_unlock();
+}
+
+static int htab_percpu_map_btf_id;
+const struct bpf_map_ops htab_percpu_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = htab_map_alloc_check,
+	.map_alloc = htab_map_alloc,
+	.map_free = htab_map_free,
+	.map_get_next_key = htab_map_get_next_key,
+	.map_lookup_elem = htab_percpu_map_lookup_elem,
+	.map_update_elem = htab_percpu_map_update_elem,
+	.map_delete_elem = htab_map_delete_elem,
+	.map_seq_show_elem = htab_percpu_map_seq_show_elem,
+	BATCH_OPS(htab_percpu),
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_percpu_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
+};
+
+static int htab_lru_percpu_map_btf_id;
+const struct bpf_map_ops htab_lru_percpu_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = htab_map_alloc_check,
+	.map_alloc = htab_map_alloc,
+	.map_free = htab_map_free,
+	.map_get_next_key = htab_map_get_next_key,
+	.map_lookup_elem = htab_lru_percpu_map_lookup_elem,
+	.map_update_elem = htab_lru_percpu_map_update_elem,
+	.map_delete_elem = htab_lru_map_delete_elem,
+	.map_seq_show_elem = htab_percpu_map_seq_show_elem,
+	BATCH_OPS(htab_lru_percpu),
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_lru_percpu_map_btf_id,
+	.iter_seq_info = &iter_seq_info,
+};
+
+static int fd_htab_map_alloc_check(union bpf_attr *attr)
+{
+	if (attr->value_size != sizeof(u32))
+		return -EINVAL;
+	return htab_map_alloc_check(attr);
+}
+
+static void fd_htab_map_free(struct bpf_map *map)
+{
+	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct hlist_nulls_node *n;
+	struct hlist_nulls_head *head;
+	struct htab_elem *l;
+	int i;
+
+	for (i = 0; i < htab->n_buckets; i++) {
+		head = select_bucket(htab, i);
+
+		hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
+			void *ptr = fd_htab_map_get_ptr(map, l);
+
+			map->ops->map_fd_put_ptr(ptr);
+		}
+	}
+
+	htab_map_free(map);
+}
+
+/* only called from syscall */
+int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
+{
+	void **ptr;
+	int ret = 0;
+
+	if (!map->ops->map_fd_sys_lookup_elem)
+		return -ENOTSUPP;
+
+	rcu_read_lock();
+	ptr = htab_map_lookup_elem(map, key);
+	if (ptr)
+		*value = map->ops->map_fd_sys_lookup_elem(READ_ONCE(*ptr));
+	else
+		ret = -ENOENT;
+	rcu_read_unlock();
+
+	return ret;
+}
+
+/* only called from syscall */
+int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
+				void *key, void *value, u64 map_flags)
+{
+	void *ptr;
+	int ret;
+	u32 ufd = *(u32 *)value;
+
+	ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
+	if (IS_ERR(ptr))
+		return PTR_ERR(ptr);
+
+	ret = htab_map_update_elem(map, key, &ptr, map_flags);
+	if (ret)
+		map->ops->map_fd_put_ptr(ptr);
+
+	return ret;
+}
+
+static struct bpf_map *htab_of_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_map *map, *inner_map_meta;
+
+	inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
+	if (IS_ERR(inner_map_meta))
+		return inner_map_meta;
+
+	map = htab_map_alloc(attr);
+	if (IS_ERR(map)) {
+		bpf_map_meta_free(inner_map_meta);
+		return map;
+	}
+
+	map->inner_map_meta = inner_map_meta;
+
+	return map;
+}
+
+static void *htab_of_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_map **inner_map  = htab_map_lookup_elem(map, key);
+
+	if (!inner_map)
+		return NULL;
+
+	return READ_ONCE(*inner_map);
+}
+
+static int htab_of_map_gen_lookup(struct bpf_map *map,
+				  struct bpf_insn *insn_buf)
+{
+	struct bpf_insn *insn = insn_buf;
+	const int ret = BPF_REG_0;
+
+	BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
+		     (void *(*)(struct bpf_map *map, void *key))NULL));
+	*insn++ = BPF_EMIT_CALL(BPF_CAST_CALL(__htab_map_lookup_elem));
+	*insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 2);
+	*insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
+				offsetof(struct htab_elem, key) +
+				round_up(map->key_size, 8));
+	*insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
+
+	return insn - insn_buf;
+}
+
+static void htab_of_map_free(struct bpf_map *map)
+{
+	bpf_map_meta_free(map->inner_map_meta);
+	fd_htab_map_free(map);
+}
+
+static int htab_of_maps_map_btf_id;
+const struct bpf_map_ops htab_of_maps_map_ops = {
+	.map_alloc_check = fd_htab_map_alloc_check,
+	.map_alloc = htab_of_map_alloc,
+	.map_free = htab_of_map_free,
+	.map_get_next_key = htab_map_get_next_key,
+	.map_lookup_elem = htab_of_map_lookup_elem,
+	.map_delete_elem = htab_map_delete_elem,
+	.map_fd_get_ptr = bpf_map_fd_get_ptr,
+	.map_fd_put_ptr = bpf_map_fd_put_ptr,
+	.map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
+	.map_gen_lookup = htab_of_map_gen_lookup,
+	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_htab",
+	.map_btf_id = &htab_of_maps_map_btf_id,
+};
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
new file mode 100644
index 000000000..0efe7c7bf
--- /dev/null
+++ b/kernel/bpf/helpers.c
@@ -0,0 +1,751 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ */
+#include <linux/bpf.h>
+#include <linux/rcupdate.h>
+#include <linux/random.h>
+#include <linux/smp.h>
+#include <linux/topology.h>
+#include <linux/ktime.h>
+#include <linux/sched.h>
+#include <linux/uidgid.h>
+#include <linux/filter.h>
+#include <linux/ctype.h>
+#include <linux/jiffies.h>
+#include <linux/pid_namespace.h>
+#include <linux/proc_ns.h>
+#include <linux/security.h>
+
+#include "../../lib/kstrtox.h"
+
+/* If kernel subsystem is allowing eBPF programs to call this function,
+ * inside its own verifier_ops->get_func_proto() callback it should return
+ * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
+ *
+ * Different map implementations will rely on rcu in map methods
+ * lookup/update/delete, therefore eBPF programs must run under rcu lock
+ * if program is allowed to access maps, so check rcu_read_lock_held in
+ * all three functions.
+ */
+BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key)
+{
+	WARN_ON_ONCE(!rcu_read_lock_held());
+	return (unsigned long) map->ops->map_lookup_elem(map, key);
+}
+
+const struct bpf_func_proto bpf_map_lookup_elem_proto = {
+	.func		= bpf_map_lookup_elem,
+	.gpl_only	= false,
+	.pkt_access	= true,
+	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_MAP_KEY,
+};
+
+BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
+	   void *, value, u64, flags)
+{
+	WARN_ON_ONCE(!rcu_read_lock_held());
+	return map->ops->map_update_elem(map, key, value, flags);
+}
+
+const struct bpf_func_proto bpf_map_update_elem_proto = {
+	.func		= bpf_map_update_elem,
+	.gpl_only	= false,
+	.pkt_access	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_MAP_KEY,
+	.arg3_type	= ARG_PTR_TO_MAP_VALUE,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
+{
+	WARN_ON_ONCE(!rcu_read_lock_held());
+	return map->ops->map_delete_elem(map, key);
+}
+
+const struct bpf_func_proto bpf_map_delete_elem_proto = {
+	.func		= bpf_map_delete_elem,
+	.gpl_only	= false,
+	.pkt_access	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_MAP_KEY,
+};
+
+BPF_CALL_3(bpf_map_push_elem, struct bpf_map *, map, void *, value, u64, flags)
+{
+	return map->ops->map_push_elem(map, value, flags);
+}
+
+const struct bpf_func_proto bpf_map_push_elem_proto = {
+	.func		= bpf_map_push_elem,
+	.gpl_only	= false,
+	.pkt_access	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_MAP_VALUE,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_map_pop_elem, struct bpf_map *, map, void *, value)
+{
+	return map->ops->map_pop_elem(map, value);
+}
+
+const struct bpf_func_proto bpf_map_pop_elem_proto = {
+	.func		= bpf_map_pop_elem,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MAP_VALUE,
+};
+
+BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value)
+{
+	return map->ops->map_peek_elem(map, value);
+}
+
+const struct bpf_func_proto bpf_map_peek_elem_proto = {
+	.func		= bpf_map_peek_elem,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MAP_VALUE,
+};
+
+const struct bpf_func_proto bpf_get_prandom_u32_proto = {
+	.func		= bpf_user_rnd_u32,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_0(bpf_get_smp_processor_id)
+{
+	return smp_processor_id();
+}
+
+const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
+	.func		= bpf_get_smp_processor_id,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_0(bpf_get_numa_node_id)
+{
+	return numa_node_id();
+}
+
+const struct bpf_func_proto bpf_get_numa_node_id_proto = {
+	.func		= bpf_get_numa_node_id,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_0(bpf_ktime_get_ns)
+{
+	/* NMI safe access to clock monotonic */
+	return ktime_get_mono_fast_ns();
+}
+
+const struct bpf_func_proto bpf_ktime_get_ns_proto = {
+	.func		= bpf_ktime_get_ns,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_0(bpf_ktime_get_boot_ns)
+{
+	/* NMI safe access to clock boottime */
+	return ktime_get_boot_fast_ns();
+}
+
+const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = {
+	.func		= bpf_ktime_get_boot_ns,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_0(bpf_get_current_pid_tgid)
+{
+	struct task_struct *task = current;
+
+	if (unlikely(!task))
+		return -EINVAL;
+
+	return (u64) task->tgid << 32 | task->pid;
+}
+
+const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
+	.func		= bpf_get_current_pid_tgid,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_0(bpf_get_current_uid_gid)
+{
+	struct task_struct *task = current;
+	kuid_t uid;
+	kgid_t gid;
+
+	if (unlikely(!task))
+		return -EINVAL;
+
+	current_uid_gid(&uid, &gid);
+	return (u64) from_kgid(&init_user_ns, gid) << 32 |
+		     from_kuid(&init_user_ns, uid);
+}
+
+const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
+	.func		= bpf_get_current_uid_gid,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size)
+{
+	struct task_struct *task = current;
+
+	if (unlikely(!task))
+		goto err_clear;
+
+	strncpy(buf, task->comm, size);
+
+	/* Verifier guarantees that size > 0. For task->comm exceeding
+	 * size, guarantee that buf is %NUL-terminated. Unconditionally
+	 * done here to save the size test.
+	 */
+	buf[size - 1] = 0;
+	return 0;
+err_clear:
+	memset(buf, 0, size);
+	return -EINVAL;
+}
+
+const struct bpf_func_proto bpf_get_current_comm_proto = {
+	.func		= bpf_get_current_comm,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE,
+};
+
+#if defined(CONFIG_QUEUED_SPINLOCKS) || defined(CONFIG_BPF_ARCH_SPINLOCK)
+
+static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
+{
+	arch_spinlock_t *l = (void *)lock;
+	union {
+		__u32 val;
+		arch_spinlock_t lock;
+	} u = { .lock = __ARCH_SPIN_LOCK_UNLOCKED };
+
+	compiletime_assert(u.val == 0, "__ARCH_SPIN_LOCK_UNLOCKED not 0");
+	BUILD_BUG_ON(sizeof(*l) != sizeof(__u32));
+	BUILD_BUG_ON(sizeof(*lock) != sizeof(__u32));
+	arch_spin_lock(l);
+}
+
+static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
+{
+	arch_spinlock_t *l = (void *)lock;
+
+	arch_spin_unlock(l);
+}
+
+#else
+
+static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
+{
+	atomic_t *l = (void *)lock;
+
+	BUILD_BUG_ON(sizeof(*l) != sizeof(*lock));
+	do {
+		atomic_cond_read_relaxed(l, !VAL);
+	} while (atomic_xchg(l, 1));
+}
+
+static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
+{
+	atomic_t *l = (void *)lock;
+
+	atomic_set_release(l, 0);
+}
+
+#endif
+
+static DEFINE_PER_CPU(unsigned long, irqsave_flags);
+
+notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__bpf_spin_lock(lock);
+	__this_cpu_write(irqsave_flags, flags);
+	return 0;
+}
+
+const struct bpf_func_proto bpf_spin_lock_proto = {
+	.func		= bpf_spin_lock,
+	.gpl_only	= false,
+	.ret_type	= RET_VOID,
+	.arg1_type	= ARG_PTR_TO_SPIN_LOCK,
+};
+
+notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
+{
+	unsigned long flags;
+
+	flags = __this_cpu_read(irqsave_flags);
+	__bpf_spin_unlock(lock);
+	local_irq_restore(flags);
+	return 0;
+}
+
+const struct bpf_func_proto bpf_spin_unlock_proto = {
+	.func		= bpf_spin_unlock,
+	.gpl_only	= false,
+	.ret_type	= RET_VOID,
+	.arg1_type	= ARG_PTR_TO_SPIN_LOCK,
+};
+
+void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
+			   bool lock_src)
+{
+	struct bpf_spin_lock *lock;
+
+	if (lock_src)
+		lock = src + map->spin_lock_off;
+	else
+		lock = dst + map->spin_lock_off;
+	preempt_disable();
+	____bpf_spin_lock(lock);
+	copy_map_value(map, dst, src);
+	____bpf_spin_unlock(lock);
+	preempt_enable();
+}
+
+BPF_CALL_0(bpf_jiffies64)
+{
+	return get_jiffies_64();
+}
+
+const struct bpf_func_proto bpf_jiffies64_proto = {
+	.func		= bpf_jiffies64,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+#ifdef CONFIG_CGROUPS
+BPF_CALL_0(bpf_get_current_cgroup_id)
+{
+	struct cgroup *cgrp = task_dfl_cgroup(current);
+
+	return cgroup_id(cgrp);
+}
+
+const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
+	.func		= bpf_get_current_cgroup_id,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_1(bpf_get_current_ancestor_cgroup_id, int, ancestor_level)
+{
+	struct cgroup *cgrp = task_dfl_cgroup(current);
+	struct cgroup *ancestor;
+
+	ancestor = cgroup_ancestor(cgrp, ancestor_level);
+	if (!ancestor)
+		return 0;
+	return cgroup_id(ancestor);
+}
+
+const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = {
+	.func		= bpf_get_current_ancestor_cgroup_id,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_ANYTHING,
+};
+
+#ifdef CONFIG_CGROUP_BPF
+DECLARE_PER_CPU(struct bpf_cgroup_storage_info,
+		bpf_cgroup_storage_info[BPF_CGROUP_STORAGE_NEST_MAX]);
+
+BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
+{
+	/* flags argument is not used now,
+	 * but provides an ability to extend the API.
+	 * verifier checks that its value is correct.
+	 */
+	enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
+	struct bpf_cgroup_storage *storage = NULL;
+	void *ptr;
+	int i;
+
+	for (i = BPF_CGROUP_STORAGE_NEST_MAX - 1; i >= 0; i--) {
+		if (likely(this_cpu_read(bpf_cgroup_storage_info[i].task) != current))
+			continue;
+
+		storage = this_cpu_read(bpf_cgroup_storage_info[i].storage[stype]);
+		break;
+	}
+
+	if (stype == BPF_CGROUP_STORAGE_SHARED)
+		ptr = &READ_ONCE(storage->buf)->data[0];
+	else
+		ptr = this_cpu_ptr(storage->percpu_buf);
+
+	return (unsigned long)ptr;
+}
+
+const struct bpf_func_proto bpf_get_local_storage_proto = {
+	.func		= bpf_get_local_storage,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MAP_VALUE,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_ANYTHING,
+};
+#endif
+
+#define BPF_STRTOX_BASE_MASK 0x1F
+
+static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
+			  unsigned long long *res, bool *is_negative)
+{
+	unsigned int base = flags & BPF_STRTOX_BASE_MASK;
+	const char *cur_buf = buf;
+	size_t cur_len = buf_len;
+	unsigned int consumed;
+	size_t val_len;
+	char str[64];
+
+	if (!buf || !buf_len || !res || !is_negative)
+		return -EINVAL;
+
+	if (base != 0 && base != 8 && base != 10 && base != 16)
+		return -EINVAL;
+
+	if (flags & ~BPF_STRTOX_BASE_MASK)
+		return -EINVAL;
+
+	while (cur_buf < buf + buf_len && isspace(*cur_buf))
+		++cur_buf;
+
+	*is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
+	if (*is_negative)
+		++cur_buf;
+
+	consumed = cur_buf - buf;
+	cur_len -= consumed;
+	if (!cur_len)
+		return -EINVAL;
+
+	cur_len = min(cur_len, sizeof(str) - 1);
+	memcpy(str, cur_buf, cur_len);
+	str[cur_len] = '\0';
+	cur_buf = str;
+
+	cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
+	val_len = _parse_integer(cur_buf, base, res);
+
+	if (val_len & KSTRTOX_OVERFLOW)
+		return -ERANGE;
+
+	if (val_len == 0)
+		return -EINVAL;
+
+	cur_buf += val_len;
+	consumed += cur_buf - str;
+
+	return consumed;
+}
+
+static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
+			 long long *res)
+{
+	unsigned long long _res;
+	bool is_negative;
+	int err;
+
+	err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
+	if (err < 0)
+		return err;
+	if (is_negative) {
+		if ((long long)-_res > 0)
+			return -ERANGE;
+		*res = -_res;
+	} else {
+		if ((long long)_res < 0)
+			return -ERANGE;
+		*res = _res;
+	}
+	return err;
+}
+
+BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
+	   long *, res)
+{
+	long long _res;
+	int err;
+
+	err = __bpf_strtoll(buf, buf_len, flags, &_res);
+	if (err < 0)
+		return err;
+	if (_res != (long)_res)
+		return -ERANGE;
+	*res = _res;
+	return err;
+}
+
+const struct bpf_func_proto bpf_strtol_proto = {
+	.func		= bpf_strtol,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_MEM,
+	.arg2_type	= ARG_CONST_SIZE,
+	.arg3_type	= ARG_ANYTHING,
+	.arg4_type	= ARG_PTR_TO_LONG,
+};
+
+BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
+	   unsigned long *, res)
+{
+	unsigned long long _res;
+	bool is_negative;
+	int err;
+
+	err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
+	if (err < 0)
+		return err;
+	if (is_negative)
+		return -EINVAL;
+	if (_res != (unsigned long)_res)
+		return -ERANGE;
+	*res = _res;
+	return err;
+}
+
+const struct bpf_func_proto bpf_strtoul_proto = {
+	.func		= bpf_strtoul,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_MEM,
+	.arg2_type	= ARG_CONST_SIZE,
+	.arg3_type	= ARG_ANYTHING,
+	.arg4_type	= ARG_PTR_TO_LONG,
+};
+#endif
+
+BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
+	   struct bpf_pidns_info *, nsdata, u32, size)
+{
+	struct task_struct *task = current;
+	struct pid_namespace *pidns;
+	int err = -EINVAL;
+
+	if (unlikely(size != sizeof(struct bpf_pidns_info)))
+		goto clear;
+
+	if (unlikely((u64)(dev_t)dev != dev))
+		goto clear;
+
+	if (unlikely(!task))
+		goto clear;
+
+	pidns = task_active_pid_ns(task);
+	if (unlikely(!pidns)) {
+		err = -ENOENT;
+		goto clear;
+	}
+
+	if (!ns_match(&pidns->ns, (dev_t)dev, ino))
+		goto clear;
+
+	nsdata->pid = task_pid_nr_ns(task, pidns);
+	nsdata->tgid = task_tgid_nr_ns(task, pidns);
+	return 0;
+clear:
+	memset((void *)nsdata, 0, (size_t) size);
+	return err;
+}
+
+const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
+	.func		= bpf_get_ns_current_pid_tgid,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_ANYTHING,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type      = ARG_PTR_TO_UNINIT_MEM,
+	.arg4_type      = ARG_CONST_SIZE,
+};
+
+static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
+	.func		= bpf_get_raw_cpu_id,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+};
+
+BPF_CALL_5(bpf_event_output_data, void *, ctx, struct bpf_map *, map,
+	   u64, flags, void *, data, u64, size)
+{
+	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
+		return -EINVAL;
+
+	return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
+}
+
+const struct bpf_func_proto bpf_event_output_data_proto =  {
+	.func		= bpf_event_output_data,
+	.gpl_only       = true,
+	.ret_type       = RET_INTEGER,
+	.arg1_type      = ARG_PTR_TO_CTX,
+	.arg2_type      = ARG_CONST_MAP_PTR,
+	.arg3_type      = ARG_ANYTHING,
+	.arg4_type      = ARG_PTR_TO_MEM,
+	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
+};
+
+BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size,
+	   const void __user *, user_ptr)
+{
+	int ret = copy_from_user(dst, user_ptr, size);
+
+	if (unlikely(ret)) {
+		memset(dst, 0, size);
+		ret = -EFAULT;
+	}
+
+	return ret;
+}
+
+const struct bpf_func_proto bpf_copy_from_user_proto = {
+	.func		= bpf_copy_from_user,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu)
+{
+	if (cpu >= nr_cpu_ids)
+		return (unsigned long)NULL;
+
+	return (unsigned long)per_cpu_ptr((const void __percpu *)ptr, cpu);
+}
+
+const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
+	.func		= bpf_per_cpu_ptr,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL,
+	.arg1_type	= ARG_PTR_TO_PERCPU_BTF_ID,
+	.arg2_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_1(bpf_this_cpu_ptr, const void *, percpu_ptr)
+{
+	return (unsigned long)this_cpu_ptr((const void __percpu *)percpu_ptr);
+}
+
+const struct bpf_func_proto bpf_this_cpu_ptr_proto = {
+	.func		= bpf_this_cpu_ptr,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_MEM_OR_BTF_ID,
+	.arg1_type	= ARG_PTR_TO_PERCPU_BTF_ID,
+};
+
+const struct bpf_func_proto bpf_get_current_task_proto __weak;
+const struct bpf_func_proto bpf_probe_read_user_proto __weak;
+const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
+const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;
+const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak;
+
+const struct bpf_func_proto *
+bpf_base_func_proto(enum bpf_func_id func_id)
+{
+	switch (func_id) {
+	case BPF_FUNC_map_lookup_elem:
+		return &bpf_map_lookup_elem_proto;
+	case BPF_FUNC_map_update_elem:
+		return &bpf_map_update_elem_proto;
+	case BPF_FUNC_map_delete_elem:
+		return &bpf_map_delete_elem_proto;
+	case BPF_FUNC_map_push_elem:
+		return &bpf_map_push_elem_proto;
+	case BPF_FUNC_map_pop_elem:
+		return &bpf_map_pop_elem_proto;
+	case BPF_FUNC_map_peek_elem:
+		return &bpf_map_peek_elem_proto;
+	case BPF_FUNC_get_prandom_u32:
+		return &bpf_get_prandom_u32_proto;
+	case BPF_FUNC_get_smp_processor_id:
+		return &bpf_get_raw_smp_processor_id_proto;
+	case BPF_FUNC_get_numa_node_id:
+		return &bpf_get_numa_node_id_proto;
+	case BPF_FUNC_tail_call:
+		return &bpf_tail_call_proto;
+	case BPF_FUNC_ktime_get_ns:
+		return &bpf_ktime_get_ns_proto;
+	case BPF_FUNC_ktime_get_boot_ns:
+		return &bpf_ktime_get_boot_ns_proto;
+	case BPF_FUNC_ringbuf_output:
+		return &bpf_ringbuf_output_proto;
+	case BPF_FUNC_ringbuf_reserve:
+		return &bpf_ringbuf_reserve_proto;
+	case BPF_FUNC_ringbuf_submit:
+		return &bpf_ringbuf_submit_proto;
+	case BPF_FUNC_ringbuf_discard:
+		return &bpf_ringbuf_discard_proto;
+	case BPF_FUNC_ringbuf_query:
+		return &bpf_ringbuf_query_proto;
+	default:
+		break;
+	}
+
+	if (!bpf_capable())
+		return NULL;
+
+	switch (func_id) {
+	case BPF_FUNC_spin_lock:
+		return &bpf_spin_lock_proto;
+	case BPF_FUNC_spin_unlock:
+		return &bpf_spin_unlock_proto;
+	case BPF_FUNC_jiffies64:
+		return &bpf_jiffies64_proto;
+	case BPF_FUNC_per_cpu_ptr:
+		return &bpf_per_cpu_ptr_proto;
+	case BPF_FUNC_this_cpu_ptr:
+		return &bpf_this_cpu_ptr_proto;
+	default:
+		break;
+	}
+
+	if (!perfmon_capable())
+		return NULL;
+
+	switch (func_id) {
+	case BPF_FUNC_trace_printk:
+		return bpf_get_trace_printk_proto();
+	case BPF_FUNC_get_current_task:
+		return &bpf_get_current_task_proto;
+	case BPF_FUNC_probe_read_user:
+		return &bpf_probe_read_user_proto;
+	case BPF_FUNC_probe_read_kernel:
+		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
+		       NULL : &bpf_probe_read_kernel_proto;
+	case BPF_FUNC_probe_read_user_str:
+		return &bpf_probe_read_user_str_proto;
+	case BPF_FUNC_probe_read_kernel_str:
+		return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
+		       NULL : &bpf_probe_read_kernel_str_proto;
+	case BPF_FUNC_snprintf_btf:
+		return &bpf_snprintf_btf_proto;
+	default:
+		return NULL;
+	}
+}
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
new file mode 100644
index 000000000..6b14b4c40
--- /dev/null
+++ b/kernel/bpf/inode.c
@@ -0,0 +1,830 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Minimal file system backend for holding eBPF maps and programs,
+ * used by bpf(2) object pinning.
+ *
+ * Authors:
+ *
+ *	Daniel Borkmann <daniel@iogearbox.net>
+ */
+
+#include <linux/init.h>
+#include <linux/magic.h>
+#include <linux/major.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/kdev_t.h>
+#include <linux/filter.h>
+#include <linux/bpf.h>
+#include <linux/bpf_trace.h>
+#include "preload/bpf_preload.h"
+
+enum bpf_type {
+	BPF_TYPE_UNSPEC	= 0,
+	BPF_TYPE_PROG,
+	BPF_TYPE_MAP,
+	BPF_TYPE_LINK,
+};
+
+static void *bpf_any_get(void *raw, enum bpf_type type)
+{
+	switch (type) {
+	case BPF_TYPE_PROG:
+		bpf_prog_inc(raw);
+		break;
+	case BPF_TYPE_MAP:
+		bpf_map_inc_with_uref(raw);
+		break;
+	case BPF_TYPE_LINK:
+		bpf_link_inc(raw);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+
+	return raw;
+}
+
+static void bpf_any_put(void *raw, enum bpf_type type)
+{
+	switch (type) {
+	case BPF_TYPE_PROG:
+		bpf_prog_put(raw);
+		break;
+	case BPF_TYPE_MAP:
+		bpf_map_put_with_uref(raw);
+		break;
+	case BPF_TYPE_LINK:
+		bpf_link_put(raw);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+}
+
+static void *bpf_fd_probe_obj(u32 ufd, enum bpf_type *type)
+{
+	void *raw;
+
+	raw = bpf_map_get_with_uref(ufd);
+	if (!IS_ERR(raw)) {
+		*type = BPF_TYPE_MAP;
+		return raw;
+	}
+
+	raw = bpf_prog_get(ufd);
+	if (!IS_ERR(raw)) {
+		*type = BPF_TYPE_PROG;
+		return raw;
+	}
+
+	raw = bpf_link_get_from_fd(ufd);
+	if (!IS_ERR(raw)) {
+		*type = BPF_TYPE_LINK;
+		return raw;
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+static const struct inode_operations bpf_dir_iops;
+
+static const struct inode_operations bpf_prog_iops = { };
+static const struct inode_operations bpf_map_iops  = { };
+static const struct inode_operations bpf_link_iops  = { };
+
+static struct inode *bpf_get_inode(struct super_block *sb,
+				   const struct inode *dir,
+				   umode_t mode)
+{
+	struct inode *inode;
+
+	switch (mode & S_IFMT) {
+	case S_IFDIR:
+	case S_IFREG:
+	case S_IFLNK:
+		break;
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+
+	inode = new_inode(sb);
+	if (!inode)
+		return ERR_PTR(-ENOSPC);
+
+	inode->i_ino = get_next_ino();
+	inode->i_atime = current_time(inode);
+	inode->i_mtime = inode->i_atime;
+	inode->i_ctime = inode->i_atime;
+
+	inode_init_owner(inode, dir, mode);
+
+	return inode;
+}
+
+static int bpf_inode_type(const struct inode *inode, enum bpf_type *type)
+{
+	*type = BPF_TYPE_UNSPEC;
+	if (inode->i_op == &bpf_prog_iops)
+		*type = BPF_TYPE_PROG;
+	else if (inode->i_op == &bpf_map_iops)
+		*type = BPF_TYPE_MAP;
+	else if (inode->i_op == &bpf_link_iops)
+		*type = BPF_TYPE_LINK;
+	else
+		return -EACCES;
+
+	return 0;
+}
+
+static void bpf_dentry_finalize(struct dentry *dentry, struct inode *inode,
+				struct inode *dir)
+{
+	d_instantiate(dentry, inode);
+	dget(dentry);
+
+	dir->i_mtime = current_time(dir);
+	dir->i_ctime = dir->i_mtime;
+}
+
+static int bpf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct inode *inode;
+
+	inode = bpf_get_inode(dir->i_sb, dir, mode | S_IFDIR);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	inode->i_op = &bpf_dir_iops;
+	inode->i_fop = &simple_dir_operations;
+
+	inc_nlink(inode);
+	inc_nlink(dir);
+
+	bpf_dentry_finalize(dentry, inode, dir);
+	return 0;
+}
+
+struct map_iter {
+	void *key;
+	bool done;
+};
+
+static struct map_iter *map_iter(struct seq_file *m)
+{
+	return m->private;
+}
+
+static struct bpf_map *seq_file_to_map(struct seq_file *m)
+{
+	return file_inode(m->file)->i_private;
+}
+
+static void map_iter_free(struct map_iter *iter)
+{
+	if (iter) {
+		kfree(iter->key);
+		kfree(iter);
+	}
+}
+
+static struct map_iter *map_iter_alloc(struct bpf_map *map)
+{
+	struct map_iter *iter;
+
+	iter = kzalloc(sizeof(*iter), GFP_KERNEL | __GFP_NOWARN);
+	if (!iter)
+		goto error;
+
+	iter->key = kzalloc(map->key_size, GFP_KERNEL | __GFP_NOWARN);
+	if (!iter->key)
+		goto error;
+
+	return iter;
+
+error:
+	map_iter_free(iter);
+	return NULL;
+}
+
+static void *map_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct bpf_map *map = seq_file_to_map(m);
+	void *key = map_iter(m)->key;
+	void *prev_key;
+
+	(*pos)++;
+	if (map_iter(m)->done)
+		return NULL;
+
+	if (unlikely(v == SEQ_START_TOKEN))
+		prev_key = NULL;
+	else
+		prev_key = key;
+
+	rcu_read_lock();
+	if (map->ops->map_get_next_key(map, prev_key, key)) {
+		map_iter(m)->done = true;
+		key = NULL;
+	}
+	rcu_read_unlock();
+	return key;
+}
+
+static void *map_seq_start(struct seq_file *m, loff_t *pos)
+{
+	if (map_iter(m)->done)
+		return NULL;
+
+	return *pos ? map_iter(m)->key : SEQ_START_TOKEN;
+}
+
+static void map_seq_stop(struct seq_file *m, void *v)
+{
+}
+
+static int map_seq_show(struct seq_file *m, void *v)
+{
+	struct bpf_map *map = seq_file_to_map(m);
+	void *key = map_iter(m)->key;
+
+	if (unlikely(v == SEQ_START_TOKEN)) {
+		seq_puts(m, "# WARNING!! The output is for debug purpose only\n");
+		seq_puts(m, "# WARNING!! The output format will change\n");
+	} else {
+		map->ops->map_seq_show_elem(map, key, m);
+	}
+
+	return 0;
+}
+
+static const struct seq_operations bpffs_map_seq_ops = {
+	.start	= map_seq_start,
+	.next	= map_seq_next,
+	.show	= map_seq_show,
+	.stop	= map_seq_stop,
+};
+
+static int bpffs_map_open(struct inode *inode, struct file *file)
+{
+	struct bpf_map *map = inode->i_private;
+	struct map_iter *iter;
+	struct seq_file *m;
+	int err;
+
+	iter = map_iter_alloc(map);
+	if (!iter)
+		return -ENOMEM;
+
+	err = seq_open(file, &bpffs_map_seq_ops);
+	if (err) {
+		map_iter_free(iter);
+		return err;
+	}
+
+	m = file->private_data;
+	m->private = iter;
+
+	return 0;
+}
+
+static int bpffs_map_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *m = file->private_data;
+
+	map_iter_free(map_iter(m));
+
+	return seq_release(inode, file);
+}
+
+/* bpffs_map_fops should only implement the basic
+ * read operation for a BPF map.  The purpose is to
+ * provide a simple user intuitive way to do
+ * "cat bpffs/pathto/a-pinned-map".
+ *
+ * Other operations (e.g. write, lookup...) should be realized by
+ * the userspace tools (e.g. bpftool) through the
+ * BPF_OBJ_GET_INFO_BY_FD and the map's lookup/update
+ * interface.
+ */
+static const struct file_operations bpffs_map_fops = {
+	.open		= bpffs_map_open,
+	.read		= seq_read,
+	.release	= bpffs_map_release,
+};
+
+static int bpffs_obj_open(struct inode *inode, struct file *file)
+{
+	return -EIO;
+}
+
+static const struct file_operations bpffs_obj_fops = {
+	.open		= bpffs_obj_open,
+};
+
+static int bpf_mkobj_ops(struct dentry *dentry, umode_t mode, void *raw,
+			 const struct inode_operations *iops,
+			 const struct file_operations *fops)
+{
+	struct inode *dir = dentry->d_parent->d_inode;
+	struct inode *inode = bpf_get_inode(dir->i_sb, dir, mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	inode->i_op = iops;
+	inode->i_fop = fops;
+	inode->i_private = raw;
+
+	bpf_dentry_finalize(dentry, inode, dir);
+	return 0;
+}
+
+static int bpf_mkprog(struct dentry *dentry, umode_t mode, void *arg)
+{
+	return bpf_mkobj_ops(dentry, mode, arg, &bpf_prog_iops,
+			     &bpffs_obj_fops);
+}
+
+static int bpf_mkmap(struct dentry *dentry, umode_t mode, void *arg)
+{
+	struct bpf_map *map = arg;
+
+	return bpf_mkobj_ops(dentry, mode, arg, &bpf_map_iops,
+			     bpf_map_support_seq_show(map) ?
+			     &bpffs_map_fops : &bpffs_obj_fops);
+}
+
+static int bpf_mklink(struct dentry *dentry, umode_t mode, void *arg)
+{
+	struct bpf_link *link = arg;
+
+	return bpf_mkobj_ops(dentry, mode, arg, &bpf_link_iops,
+			     bpf_link_is_iter(link) ?
+			     &bpf_iter_fops : &bpffs_obj_fops);
+}
+
+static struct dentry *
+bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags)
+{
+	/* Dots in names (e.g. "/sys/fs/bpf/foo.bar") are reserved for future
+	 * extensions. That allows popoulate_bpffs() create special files.
+	 */
+	if ((dir->i_mode & S_IALLUGO) &&
+	    strchr(dentry->d_name.name, '.'))
+		return ERR_PTR(-EPERM);
+
+	return simple_lookup(dir, dentry, flags);
+}
+
+static int bpf_symlink(struct inode *dir, struct dentry *dentry,
+		       const char *target)
+{
+	char *link = kstrdup(target, GFP_USER | __GFP_NOWARN);
+	struct inode *inode;
+
+	if (!link)
+		return -ENOMEM;
+
+	inode = bpf_get_inode(dir->i_sb, dir, S_IRWXUGO | S_IFLNK);
+	if (IS_ERR(inode)) {
+		kfree(link);
+		return PTR_ERR(inode);
+	}
+
+	inode->i_op = &simple_symlink_inode_operations;
+	inode->i_link = link;
+
+	bpf_dentry_finalize(dentry, inode, dir);
+	return 0;
+}
+
+static const struct inode_operations bpf_dir_iops = {
+	.lookup		= bpf_lookup,
+	.mkdir		= bpf_mkdir,
+	.symlink	= bpf_symlink,
+	.rmdir		= simple_rmdir,
+	.rename		= simple_rename,
+	.link		= simple_link,
+	.unlink		= simple_unlink,
+};
+
+/* pin iterator link into bpffs */
+static int bpf_iter_link_pin_kernel(struct dentry *parent,
+				    const char *name, struct bpf_link *link)
+{
+	umode_t mode = S_IFREG | S_IRUSR;
+	struct dentry *dentry;
+	int ret;
+
+	inode_lock(parent->d_inode);
+	dentry = lookup_one_len(name, parent, strlen(name));
+	if (IS_ERR(dentry)) {
+		inode_unlock(parent->d_inode);
+		return PTR_ERR(dentry);
+	}
+	ret = bpf_mkobj_ops(dentry, mode, link, &bpf_link_iops,
+			    &bpf_iter_fops);
+	dput(dentry);
+	inode_unlock(parent->d_inode);
+	return ret;
+}
+
+static int bpf_obj_do_pin(const char __user *pathname, void *raw,
+			  enum bpf_type type)
+{
+	struct dentry *dentry;
+	struct inode *dir;
+	struct path path;
+	umode_t mode;
+	int ret;
+
+	dentry = user_path_create(AT_FDCWD, pathname, &path, 0);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	mode = S_IFREG | ((S_IRUSR | S_IWUSR) & ~current_umask());
+
+	ret = security_path_mknod(&path, dentry, mode, 0);
+	if (ret)
+		goto out;
+
+	dir = d_inode(path.dentry);
+	if (dir->i_op != &bpf_dir_iops) {
+		ret = -EPERM;
+		goto out;
+	}
+
+	switch (type) {
+	case BPF_TYPE_PROG:
+		ret = vfs_mkobj(dentry, mode, bpf_mkprog, raw);
+		break;
+	case BPF_TYPE_MAP:
+		ret = vfs_mkobj(dentry, mode, bpf_mkmap, raw);
+		break;
+	case BPF_TYPE_LINK:
+		ret = vfs_mkobj(dentry, mode, bpf_mklink, raw);
+		break;
+	default:
+		ret = -EPERM;
+	}
+out:
+	done_path_create(&path, dentry);
+	return ret;
+}
+
+int bpf_obj_pin_user(u32 ufd, const char __user *pathname)
+{
+	enum bpf_type type;
+	void *raw;
+	int ret;
+
+	raw = bpf_fd_probe_obj(ufd, &type);
+	if (IS_ERR(raw))
+		return PTR_ERR(raw);
+
+	ret = bpf_obj_do_pin(pathname, raw, type);
+	if (ret != 0)
+		bpf_any_put(raw, type);
+
+	return ret;
+}
+
+static void *bpf_obj_do_get(const char __user *pathname,
+			    enum bpf_type *type, int flags)
+{
+	struct inode *inode;
+	struct path path;
+	void *raw;
+	int ret;
+
+	ret = user_path_at(AT_FDCWD, pathname, LOOKUP_FOLLOW, &path);
+	if (ret)
+		return ERR_PTR(ret);
+
+	inode = d_backing_inode(path.dentry);
+	ret = inode_permission(inode, ACC_MODE(flags));
+	if (ret)
+		goto out;
+
+	ret = bpf_inode_type(inode, type);
+	if (ret)
+		goto out;
+
+	raw = bpf_any_get(inode->i_private, *type);
+	if (!IS_ERR(raw))
+		touch_atime(&path);
+
+	path_put(&path);
+	return raw;
+out:
+	path_put(&path);
+	return ERR_PTR(ret);
+}
+
+int bpf_obj_get_user(const char __user *pathname, int flags)
+{
+	enum bpf_type type = BPF_TYPE_UNSPEC;
+	int f_flags;
+	void *raw;
+	int ret;
+
+	f_flags = bpf_get_file_flag(flags);
+	if (f_flags < 0)
+		return f_flags;
+
+	raw = bpf_obj_do_get(pathname, &type, f_flags);
+	if (IS_ERR(raw))
+		return PTR_ERR(raw);
+
+	if (type == BPF_TYPE_PROG)
+		ret = bpf_prog_new_fd(raw);
+	else if (type == BPF_TYPE_MAP)
+		ret = bpf_map_new_fd(raw, f_flags);
+	else if (type == BPF_TYPE_LINK)
+		ret = (f_flags != O_RDWR) ? -EINVAL : bpf_link_new_fd(raw);
+	else
+		return -ENOENT;
+
+	if (ret < 0)
+		bpf_any_put(raw, type);
+	return ret;
+}
+
+static struct bpf_prog *__get_prog_inode(struct inode *inode, enum bpf_prog_type type)
+{
+	struct bpf_prog *prog;
+	int ret = inode_permission(inode, MAY_READ);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (inode->i_op == &bpf_map_iops)
+		return ERR_PTR(-EINVAL);
+	if (inode->i_op == &bpf_link_iops)
+		return ERR_PTR(-EINVAL);
+	if (inode->i_op != &bpf_prog_iops)
+		return ERR_PTR(-EACCES);
+
+	prog = inode->i_private;
+
+	ret = security_bpf_prog(prog);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	if (!bpf_prog_get_ok(prog, &type, false))
+		return ERR_PTR(-EINVAL);
+
+	bpf_prog_inc(prog);
+	return prog;
+}
+
+struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type type)
+{
+	struct bpf_prog *prog;
+	struct path path;
+	int ret = kern_path(name, LOOKUP_FOLLOW, &path);
+	if (ret)
+		return ERR_PTR(ret);
+	prog = __get_prog_inode(d_backing_inode(path.dentry), type);
+	if (!IS_ERR(prog))
+		touch_atime(&path);
+	path_put(&path);
+	return prog;
+}
+EXPORT_SYMBOL(bpf_prog_get_type_path);
+
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int bpf_show_options(struct seq_file *m, struct dentry *root)
+{
+	umode_t mode = d_inode(root)->i_mode & S_IALLUGO & ~S_ISVTX;
+
+	if (mode != S_IRWXUGO)
+		seq_printf(m, ",mode=%o", mode);
+	return 0;
+}
+
+static void bpf_free_inode(struct inode *inode)
+{
+	enum bpf_type type;
+
+	if (S_ISLNK(inode->i_mode))
+		kfree(inode->i_link);
+	if (!bpf_inode_type(inode, &type))
+		bpf_any_put(inode->i_private, type);
+	free_inode_nonrcu(inode);
+}
+
+static const struct super_operations bpf_super_ops = {
+	.statfs		= simple_statfs,
+	.drop_inode	= generic_delete_inode,
+	.show_options	= bpf_show_options,
+	.free_inode	= bpf_free_inode,
+};
+
+enum {
+	OPT_MODE,
+};
+
+static const struct fs_parameter_spec bpf_fs_parameters[] = {
+	fsparam_u32oct	("mode",			OPT_MODE),
+	{}
+};
+
+struct bpf_mount_opts {
+	umode_t mode;
+};
+
+static int bpf_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct bpf_mount_opts *opts = fc->fs_private;
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, bpf_fs_parameters, param, &result);
+	if (opt < 0)
+		/* We might like to report bad mount options here, but
+		 * traditionally we've ignored all mount options, so we'd
+		 * better continue to ignore non-existing options for bpf.
+		 */
+		return opt == -ENOPARAM ? 0 : opt;
+
+	switch (opt) {
+	case OPT_MODE:
+		opts->mode = result.uint_32 & S_IALLUGO;
+		break;
+	}
+
+	return 0;
+}
+
+struct bpf_preload_ops *bpf_preload_ops;
+EXPORT_SYMBOL_GPL(bpf_preload_ops);
+
+static bool bpf_preload_mod_get(void)
+{
+	/* If bpf_preload.ko wasn't loaded earlier then load it now.
+	 * When bpf_preload is built into vmlinux the module's __init
+	 * function will populate it.
+	 */
+	if (!bpf_preload_ops) {
+		request_module("bpf_preload");
+		if (!bpf_preload_ops)
+			return false;
+	}
+	/* And grab the reference, so the module doesn't disappear while the
+	 * kernel is interacting with the kernel module and its UMD.
+	 */
+	if (!try_module_get(bpf_preload_ops->owner)) {
+		pr_err("bpf_preload module get failed.\n");
+		return false;
+	}
+	return true;
+}
+
+static void bpf_preload_mod_put(void)
+{
+	if (bpf_preload_ops)
+		/* now user can "rmmod bpf_preload" if necessary */
+		module_put(bpf_preload_ops->owner);
+}
+
+static DEFINE_MUTEX(bpf_preload_lock);
+
+static int populate_bpffs(struct dentry *parent)
+{
+	struct bpf_preload_info objs[BPF_PRELOAD_LINKS] = {};
+	struct bpf_link *links[BPF_PRELOAD_LINKS] = {};
+	int err = 0, i;
+
+	/* grab the mutex to make sure the kernel interactions with bpf_preload
+	 * UMD are serialized
+	 */
+	mutex_lock(&bpf_preload_lock);
+
+	/* if bpf_preload.ko wasn't built into vmlinux then load it */
+	if (!bpf_preload_mod_get())
+		goto out;
+
+	if (!bpf_preload_ops->info.tgid) {
+		/* preload() will start UMD that will load BPF iterator programs */
+		err = bpf_preload_ops->preload(objs);
+		if (err)
+			goto out_put;
+		for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
+			links[i] = bpf_link_by_id(objs[i].link_id);
+			if (IS_ERR(links[i])) {
+				err = PTR_ERR(links[i]);
+				goto out_put;
+			}
+		}
+		for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
+			err = bpf_iter_link_pin_kernel(parent,
+						       objs[i].link_name, links[i]);
+			if (err)
+				goto out_put;
+			/* do not unlink successfully pinned links even
+			 * if later link fails to pin
+			 */
+			links[i] = NULL;
+		}
+		/* finish() will tell UMD process to exit */
+		err = bpf_preload_ops->finish();
+		if (err)
+			goto out_put;
+	}
+out_put:
+	bpf_preload_mod_put();
+out:
+	mutex_unlock(&bpf_preload_lock);
+	for (i = 0; i < BPF_PRELOAD_LINKS && err; i++)
+		if (!IS_ERR_OR_NULL(links[i]))
+			bpf_link_put(links[i]);
+	return err;
+}
+
+static int bpf_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	static const struct tree_descr bpf_rfiles[] = { { "" } };
+	struct bpf_mount_opts *opts = fc->fs_private;
+	struct inode *inode;
+	int ret;
+
+	ret = simple_fill_super(sb, BPF_FS_MAGIC, bpf_rfiles);
+	if (ret)
+		return ret;
+
+	sb->s_op = &bpf_super_ops;
+
+	inode = sb->s_root->d_inode;
+	inode->i_op = &bpf_dir_iops;
+	inode->i_mode &= ~S_IALLUGO;
+	populate_bpffs(sb->s_root);
+	inode->i_mode |= S_ISVTX | opts->mode;
+	return 0;
+}
+
+static int bpf_get_tree(struct fs_context *fc)
+{
+	return get_tree_nodev(fc, bpf_fill_super);
+}
+
+static void bpf_free_fc(struct fs_context *fc)
+{
+	kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations bpf_context_ops = {
+	.free		= bpf_free_fc,
+	.parse_param	= bpf_parse_param,
+	.get_tree	= bpf_get_tree,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int bpf_init_fs_context(struct fs_context *fc)
+{
+	struct bpf_mount_opts *opts;
+
+	opts = kzalloc(sizeof(struct bpf_mount_opts), GFP_KERNEL);
+	if (!opts)
+		return -ENOMEM;
+
+	opts->mode = S_IRWXUGO;
+
+	fc->fs_private = opts;
+	fc->ops = &bpf_context_ops;
+	return 0;
+}
+
+static struct file_system_type bpf_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "bpf",
+	.init_fs_context = bpf_init_fs_context,
+	.parameters	= bpf_fs_parameters,
+	.kill_sb	= kill_litter_super,
+};
+
+static int __init bpf_init(void)
+{
+	int ret;
+
+	mutex_init(&bpf_preload_lock);
+
+	ret = sysfs_create_mount_point(fs_kobj, "bpf");
+	if (ret)
+		return ret;
+
+	ret = register_filesystem(&bpf_fs_type);
+	if (ret)
+		sysfs_remove_mount_point(fs_kobj, "bpf");
+
+	return ret;
+}
+fs_initcall(bpf_init);
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
new file mode 100644
index 000000000..b139247d2
--- /dev/null
+++ b/kernel/bpf/local_storage.c
@@ -0,0 +1,622 @@
+//SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf-cgroup.h>
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/bug.h>
+#include <linux/filter.h>
+#include <linux/mm.h>
+#include <linux/rbtree.h>
+#include <linux/slab.h>
+#include <uapi/linux/btf.h>
+
+#ifdef CONFIG_CGROUP_BPF
+
+DEFINE_PER_CPU(struct bpf_cgroup_storage_info,
+	       bpf_cgroup_storage_info[BPF_CGROUP_STORAGE_NEST_MAX]);
+
+#include "../cgroup/cgroup-internal.h"
+
+#define LOCAL_STORAGE_CREATE_FLAG_MASK					\
+	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
+
+struct bpf_cgroup_storage_map {
+	struct bpf_map map;
+
+	spinlock_t lock;
+	struct rb_root root;
+	struct list_head list;
+};
+
+static struct bpf_cgroup_storage_map *map_to_storage(struct bpf_map *map)
+{
+	return container_of(map, struct bpf_cgroup_storage_map, map);
+}
+
+static bool attach_type_isolated(const struct bpf_map *map)
+{
+	return map->key_size == sizeof(struct bpf_cgroup_storage_key);
+}
+
+static int bpf_cgroup_storage_key_cmp(const struct bpf_cgroup_storage_map *map,
+				      const void *_key1, const void *_key2)
+{
+	if (attach_type_isolated(&map->map)) {
+		const struct bpf_cgroup_storage_key *key1 = _key1;
+		const struct bpf_cgroup_storage_key *key2 = _key2;
+
+		if (key1->cgroup_inode_id < key2->cgroup_inode_id)
+			return -1;
+		else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
+			return 1;
+		else if (key1->attach_type < key2->attach_type)
+			return -1;
+		else if (key1->attach_type > key2->attach_type)
+			return 1;
+	} else {
+		const __u64 *cgroup_inode_id1 = _key1;
+		const __u64 *cgroup_inode_id2 = _key2;
+
+		if (*cgroup_inode_id1 < *cgroup_inode_id2)
+			return -1;
+		else if (*cgroup_inode_id1 > *cgroup_inode_id2)
+			return 1;
+	}
+	return 0;
+}
+
+struct bpf_cgroup_storage *
+cgroup_storage_lookup(struct bpf_cgroup_storage_map *map,
+		      void *key, bool locked)
+{
+	struct rb_root *root = &map->root;
+	struct rb_node *node;
+
+	if (!locked)
+		spin_lock_bh(&map->lock);
+
+	node = root->rb_node;
+	while (node) {
+		struct bpf_cgroup_storage *storage;
+
+		storage = container_of(node, struct bpf_cgroup_storage, node);
+
+		switch (bpf_cgroup_storage_key_cmp(map, key, &storage->key)) {
+		case -1:
+			node = node->rb_left;
+			break;
+		case 1:
+			node = node->rb_right;
+			break;
+		default:
+			if (!locked)
+				spin_unlock_bh(&map->lock);
+			return storage;
+		}
+	}
+
+	if (!locked)
+		spin_unlock_bh(&map->lock);
+
+	return NULL;
+}
+
+static int cgroup_storage_insert(struct bpf_cgroup_storage_map *map,
+				 struct bpf_cgroup_storage *storage)
+{
+	struct rb_root *root = &map->root;
+	struct rb_node **new = &(root->rb_node), *parent = NULL;
+
+	while (*new) {
+		struct bpf_cgroup_storage *this;
+
+		this = container_of(*new, struct bpf_cgroup_storage, node);
+
+		parent = *new;
+		switch (bpf_cgroup_storage_key_cmp(map, &storage->key, &this->key)) {
+		case -1:
+			new = &((*new)->rb_left);
+			break;
+		case 1:
+			new = &((*new)->rb_right);
+			break;
+		default:
+			return -EEXIST;
+		}
+	}
+
+	rb_link_node(&storage->node, parent, new);
+	rb_insert_color(&storage->node, root);
+
+	return 0;
+}
+
+static void *cgroup_storage_lookup_elem(struct bpf_map *_map, void *key)
+{
+	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
+	struct bpf_cgroup_storage *storage;
+
+	storage = cgroup_storage_lookup(map, key, false);
+	if (!storage)
+		return NULL;
+
+	return &READ_ONCE(storage->buf)->data[0];
+}
+
+static int cgroup_storage_update_elem(struct bpf_map *map, void *key,
+				      void *value, u64 flags)
+{
+	struct bpf_cgroup_storage *storage;
+	struct bpf_storage_buffer *new;
+
+	if (unlikely(flags & ~(BPF_F_LOCK | BPF_EXIST)))
+		return -EINVAL;
+
+	if (unlikely((flags & BPF_F_LOCK) &&
+		     !map_value_has_spin_lock(map)))
+		return -EINVAL;
+
+	storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
+					key, false);
+	if (!storage)
+		return -ENOENT;
+
+	if (flags & BPF_F_LOCK) {
+		copy_map_value_locked(map, storage->buf->data, value, false);
+		return 0;
+	}
+
+	new = kmalloc_node(sizeof(struct bpf_storage_buffer) +
+			   map->value_size,
+			   __GFP_ZERO | GFP_ATOMIC | __GFP_NOWARN,
+			   map->numa_node);
+	if (!new)
+		return -ENOMEM;
+
+	memcpy(&new->data[0], value, map->value_size);
+	check_and_init_map_lock(map, new->data);
+
+	new = xchg(&storage->buf, new);
+	kfree_rcu(new, rcu);
+
+	return 0;
+}
+
+int bpf_percpu_cgroup_storage_copy(struct bpf_map *_map, void *key,
+				   void *value)
+{
+	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
+	struct bpf_cgroup_storage *storage;
+	int cpu, off = 0;
+	u32 size;
+
+	rcu_read_lock();
+	storage = cgroup_storage_lookup(map, key, false);
+	if (!storage) {
+		rcu_read_unlock();
+		return -ENOENT;
+	}
+
+	/* per_cpu areas are zero-filled and bpf programs can only
+	 * access 'value_size' of them, so copying rounded areas
+	 * will not leak any kernel data
+	 */
+	size = round_up(_map->value_size, 8);
+	for_each_possible_cpu(cpu) {
+		bpf_long_memcpy(value + off,
+				per_cpu_ptr(storage->percpu_buf, cpu), size);
+		off += size;
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+int bpf_percpu_cgroup_storage_update(struct bpf_map *_map, void *key,
+				     void *value, u64 map_flags)
+{
+	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
+	struct bpf_cgroup_storage *storage;
+	int cpu, off = 0;
+	u32 size;
+
+	if (map_flags != BPF_ANY && map_flags != BPF_EXIST)
+		return -EINVAL;
+
+	rcu_read_lock();
+	storage = cgroup_storage_lookup(map, key, false);
+	if (!storage) {
+		rcu_read_unlock();
+		return -ENOENT;
+	}
+
+	/* the user space will provide round_up(value_size, 8) bytes that
+	 * will be copied into per-cpu area. bpf programs can only access
+	 * value_size of it. During lookup the same extra bytes will be
+	 * returned or zeros which were zero-filled by percpu_alloc,
+	 * so no kernel data leaks possible
+	 */
+	size = round_up(_map->value_size, 8);
+	for_each_possible_cpu(cpu) {
+		bpf_long_memcpy(per_cpu_ptr(storage->percpu_buf, cpu),
+				value + off, size);
+		off += size;
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+static int cgroup_storage_get_next_key(struct bpf_map *_map, void *key,
+				       void *_next_key)
+{
+	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
+	struct bpf_cgroup_storage *storage;
+
+	spin_lock_bh(&map->lock);
+
+	if (list_empty(&map->list))
+		goto enoent;
+
+	if (key) {
+		storage = cgroup_storage_lookup(map, key, true);
+		if (!storage)
+			goto enoent;
+
+		storage = list_next_entry(storage, list_map);
+		if (!storage)
+			goto enoent;
+	} else {
+		storage = list_first_entry(&map->list,
+					 struct bpf_cgroup_storage, list_map);
+	}
+
+	spin_unlock_bh(&map->lock);
+
+	if (attach_type_isolated(&map->map)) {
+		struct bpf_cgroup_storage_key *next = _next_key;
+		*next = storage->key;
+	} else {
+		__u64 *next = _next_key;
+		*next = storage->key.cgroup_inode_id;
+	}
+	return 0;
+
+enoent:
+	spin_unlock_bh(&map->lock);
+	return -ENOENT;
+}
+
+static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
+{
+	int numa_node = bpf_map_attr_numa_node(attr);
+	struct bpf_cgroup_storage_map *map;
+	struct bpf_map_memory mem;
+	int ret;
+
+	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
+	    attr->key_size != sizeof(__u64))
+		return ERR_PTR(-EINVAL);
+
+	if (attr->value_size == 0)
+		return ERR_PTR(-EINVAL);
+
+	if (attr->value_size > PAGE_SIZE)
+		return ERR_PTR(-E2BIG);
+
+	if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags))
+		return ERR_PTR(-EINVAL);
+
+	if (attr->max_entries)
+		/* max_entries is not used and enforced to be 0 */
+		return ERR_PTR(-EINVAL);
+
+	ret = bpf_map_charge_init(&mem, sizeof(struct bpf_cgroup_storage_map));
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
+			   __GFP_ZERO | GFP_USER, numa_node);
+	if (!map) {
+		bpf_map_charge_finish(&mem);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	bpf_map_charge_move(&map->map.memory, &mem);
+
+	/* copy mandatory map attributes */
+	bpf_map_init_from_attr(&map->map, attr);
+
+	spin_lock_init(&map->lock);
+	map->root = RB_ROOT;
+	INIT_LIST_HEAD(&map->list);
+
+	return &map->map;
+}
+
+static void cgroup_storage_map_free(struct bpf_map *_map)
+{
+	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
+	struct list_head *storages = &map->list;
+	struct bpf_cgroup_storage *storage, *stmp;
+
+	mutex_lock(&cgroup_mutex);
+
+	list_for_each_entry_safe(storage, stmp, storages, list_map) {
+		bpf_cgroup_storage_unlink(storage);
+		bpf_cgroup_storage_free(storage);
+	}
+
+	mutex_unlock(&cgroup_mutex);
+
+	WARN_ON(!RB_EMPTY_ROOT(&map->root));
+	WARN_ON(!list_empty(&map->list));
+
+	kfree(map);
+}
+
+static int cgroup_storage_delete_elem(struct bpf_map *map, void *key)
+{
+	return -EINVAL;
+}
+
+static int cgroup_storage_check_btf(const struct bpf_map *map,
+				    const struct btf *btf,
+				    const struct btf_type *key_type,
+				    const struct btf_type *value_type)
+{
+	if (attach_type_isolated(map)) {
+		struct btf_member *m;
+		u32 offset, size;
+
+		/* Key is expected to be of struct bpf_cgroup_storage_key type,
+		 * which is:
+		 * struct bpf_cgroup_storage_key {
+		 *	__u64	cgroup_inode_id;
+		 *	__u32	attach_type;
+		 * };
+		 */
+
+		/*
+		 * Key_type must be a structure with two fields.
+		 */
+		if (BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ||
+		    BTF_INFO_VLEN(key_type->info) != 2)
+			return -EINVAL;
+
+		/*
+		 * The first field must be a 64 bit integer at 0 offset.
+		 */
+		m = (struct btf_member *)(key_type + 1);
+		size = sizeof_field(struct bpf_cgroup_storage_key, cgroup_inode_id);
+		if (!btf_member_is_reg_int(btf, key_type, m, 0, size))
+			return -EINVAL;
+
+		/*
+		 * The second field must be a 32 bit integer at 64 bit offset.
+		 */
+		m++;
+		offset = offsetof(struct bpf_cgroup_storage_key, attach_type);
+		size = sizeof_field(struct bpf_cgroup_storage_key, attach_type);
+		if (!btf_member_is_reg_int(btf, key_type, m, offset, size))
+			return -EINVAL;
+	} else {
+		u32 int_data;
+
+		/*
+		 * Key is expected to be u64, which stores the cgroup_inode_id
+		 */
+
+		if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
+			return -EINVAL;
+
+		int_data = *(u32 *)(key_type + 1);
+		if (BTF_INT_BITS(int_data) != 64 || BTF_INT_OFFSET(int_data))
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void cgroup_storage_seq_show_elem(struct bpf_map *map, void *key,
+					 struct seq_file *m)
+{
+	enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
+	struct bpf_cgroup_storage *storage;
+	int cpu;
+
+	rcu_read_lock();
+	storage = cgroup_storage_lookup(map_to_storage(map), key, false);
+	if (!storage) {
+		rcu_read_unlock();
+		return;
+	}
+
+	btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
+	stype = cgroup_storage_type(map);
+	if (stype == BPF_CGROUP_STORAGE_SHARED) {
+		seq_puts(m, ": ");
+		btf_type_seq_show(map->btf, map->btf_value_type_id,
+				  &READ_ONCE(storage->buf)->data[0], m);
+		seq_puts(m, "\n");
+	} else {
+		seq_puts(m, ": {\n");
+		for_each_possible_cpu(cpu) {
+			seq_printf(m, "\tcpu%d: ", cpu);
+			btf_type_seq_show(map->btf, map->btf_value_type_id,
+					  per_cpu_ptr(storage->percpu_buf, cpu),
+					  m);
+			seq_puts(m, "\n");
+		}
+		seq_puts(m, "}\n");
+	}
+	rcu_read_unlock();
+}
+
+static int cgroup_storage_map_btf_id;
+const struct bpf_map_ops cgroup_storage_map_ops = {
+	.map_alloc = cgroup_storage_map_alloc,
+	.map_free = cgroup_storage_map_free,
+	.map_get_next_key = cgroup_storage_get_next_key,
+	.map_lookup_elem = cgroup_storage_lookup_elem,
+	.map_update_elem = cgroup_storage_update_elem,
+	.map_delete_elem = cgroup_storage_delete_elem,
+	.map_check_btf = cgroup_storage_check_btf,
+	.map_seq_show_elem = cgroup_storage_seq_show_elem,
+	.map_btf_name = "bpf_cgroup_storage_map",
+	.map_btf_id = &cgroup_storage_map_btf_id,
+};
+
+int bpf_cgroup_storage_assign(struct bpf_prog_aux *aux, struct bpf_map *_map)
+{
+	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
+
+	if (aux->cgroup_storage[stype] &&
+	    aux->cgroup_storage[stype] != _map)
+		return -EBUSY;
+
+	aux->cgroup_storage[stype] = _map;
+	return 0;
+}
+
+static size_t bpf_cgroup_storage_calculate_size(struct bpf_map *map, u32 *pages)
+{
+	size_t size;
+
+	if (cgroup_storage_type(map) == BPF_CGROUP_STORAGE_SHARED) {
+		size = sizeof(struct bpf_storage_buffer) + map->value_size;
+		*pages = round_up(sizeof(struct bpf_cgroup_storage) + size,
+				  PAGE_SIZE) >> PAGE_SHIFT;
+	} else {
+		size = map->value_size;
+		*pages = round_up(round_up(size, 8) * num_possible_cpus(),
+				  PAGE_SIZE) >> PAGE_SHIFT;
+	}
+
+	return size;
+}
+
+struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog,
+					enum bpf_cgroup_storage_type stype)
+{
+	struct bpf_cgroup_storage *storage;
+	struct bpf_map *map;
+	gfp_t flags;
+	size_t size;
+	u32 pages;
+
+	map = prog->aux->cgroup_storage[stype];
+	if (!map)
+		return NULL;
+
+	size = bpf_cgroup_storage_calculate_size(map, &pages);
+
+	if (bpf_map_charge_memlock(map, pages))
+		return ERR_PTR(-EPERM);
+
+	storage = kmalloc_node(sizeof(struct bpf_cgroup_storage),
+			       __GFP_ZERO | GFP_USER, map->numa_node);
+	if (!storage)
+		goto enomem;
+
+	flags = __GFP_ZERO | GFP_USER;
+
+	if (stype == BPF_CGROUP_STORAGE_SHARED) {
+		storage->buf = kmalloc_node(size, flags, map->numa_node);
+		if (!storage->buf)
+			goto enomem;
+		check_and_init_map_lock(map, storage->buf->data);
+	} else {
+		storage->percpu_buf = __alloc_percpu_gfp(size, 8, flags);
+		if (!storage->percpu_buf)
+			goto enomem;
+	}
+
+	storage->map = (struct bpf_cgroup_storage_map *)map;
+
+	return storage;
+
+enomem:
+	bpf_map_uncharge_memlock(map, pages);
+	kfree(storage);
+	return ERR_PTR(-ENOMEM);
+}
+
+static void free_shared_cgroup_storage_rcu(struct rcu_head *rcu)
+{
+	struct bpf_cgroup_storage *storage =
+		container_of(rcu, struct bpf_cgroup_storage, rcu);
+
+	kfree(storage->buf);
+	kfree(storage);
+}
+
+static void free_percpu_cgroup_storage_rcu(struct rcu_head *rcu)
+{
+	struct bpf_cgroup_storage *storage =
+		container_of(rcu, struct bpf_cgroup_storage, rcu);
+
+	free_percpu(storage->percpu_buf);
+	kfree(storage);
+}
+
+void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
+{
+	enum bpf_cgroup_storage_type stype;
+	struct bpf_map *map;
+	u32 pages;
+
+	if (!storage)
+		return;
+
+	map = &storage->map->map;
+
+	bpf_cgroup_storage_calculate_size(map, &pages);
+	bpf_map_uncharge_memlock(map, pages);
+
+	stype = cgroup_storage_type(map);
+	if (stype == BPF_CGROUP_STORAGE_SHARED)
+		call_rcu(&storage->rcu, free_shared_cgroup_storage_rcu);
+	else
+		call_rcu(&storage->rcu, free_percpu_cgroup_storage_rcu);
+}
+
+void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
+			     struct cgroup *cgroup,
+			     enum bpf_attach_type type)
+{
+	struct bpf_cgroup_storage_map *map;
+
+	if (!storage)
+		return;
+
+	storage->key.attach_type = type;
+	storage->key.cgroup_inode_id = cgroup_id(cgroup);
+
+	map = storage->map;
+
+	spin_lock_bh(&map->lock);
+	WARN_ON(cgroup_storage_insert(map, storage));
+	list_add(&storage->list_map, &map->list);
+	list_add(&storage->list_cg, &cgroup->bpf.storages);
+	spin_unlock_bh(&map->lock);
+}
+
+void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage)
+{
+	struct bpf_cgroup_storage_map *map;
+	struct rb_root *root;
+
+	if (!storage)
+		return;
+
+	map = storage->map;
+
+	spin_lock_bh(&map->lock);
+	root = &map->root;
+	rb_erase(&storage->node, root);
+
+	list_del(&storage->list_map);
+	list_del(&storage->list_cg);
+	spin_unlock_bh(&map->lock);
+}
+
+#endif
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
new file mode 100644
index 000000000..3c2d8722d
--- /dev/null
+++ b/kernel/bpf/lpm_trie.c
@@ -0,0 +1,748 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Longest prefix match list implementation
+ *
+ * Copyright (c) 2016,2017 Daniel Mack
+ * Copyright (c) 2016 David Herrmann
+ */
+
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <net/ipv6.h>
+#include <uapi/linux/btf.h>
+
+/* Intermediate node */
+#define LPM_TREE_NODE_FLAG_IM BIT(0)
+
+struct lpm_trie_node;
+
+struct lpm_trie_node {
+	struct rcu_head rcu;
+	struct lpm_trie_node __rcu	*child[2];
+	u32				prefixlen;
+	u32				flags;
+	u8				data[];
+};
+
+struct lpm_trie {
+	struct bpf_map			map;
+	struct lpm_trie_node __rcu	*root;
+	size_t				n_entries;
+	size_t				max_prefixlen;
+	size_t				data_size;
+	spinlock_t			lock;
+};
+
+/* This trie implements a longest prefix match algorithm that can be used to
+ * match IP addresses to a stored set of ranges.
+ *
+ * Data stored in @data of struct bpf_lpm_key and struct lpm_trie_node is
+ * interpreted as big endian, so data[0] stores the most significant byte.
+ *
+ * Match ranges are internally stored in instances of struct lpm_trie_node
+ * which each contain their prefix length as well as two pointers that may
+ * lead to more nodes containing more specific matches. Each node also stores
+ * a value that is defined by and returned to userspace via the update_elem
+ * and lookup functions.
+ *
+ * For instance, let's start with a trie that was created with a prefix length
+ * of 32, so it can be used for IPv4 addresses, and one single element that
+ * matches 192.168.0.0/16. The data array would hence contain
+ * [0xc0, 0xa8, 0x00, 0x00] in big-endian notation. This documentation will
+ * stick to IP-address notation for readability though.
+ *
+ * As the trie is empty initially, the new node (1) will be places as root
+ * node, denoted as (R) in the example below. As there are no other node, both
+ * child pointers are %NULL.
+ *
+ *              +----------------+
+ *              |       (1)  (R) |
+ *              | 192.168.0.0/16 |
+ *              |    value: 1    |
+ *              |   [0]    [1]   |
+ *              +----------------+
+ *
+ * Next, let's add a new node (2) matching 192.168.0.0/24. As there is already
+ * a node with the same data and a smaller prefix (ie, a less specific one),
+ * node (2) will become a child of (1). In child index depends on the next bit
+ * that is outside of what (1) matches, and that bit is 0, so (2) will be
+ * child[0] of (1):
+ *
+ *              +----------------+
+ *              |       (1)  (R) |
+ *              | 192.168.0.0/16 |
+ *              |    value: 1    |
+ *              |   [0]    [1]   |
+ *              +----------------+
+ *                   |
+ *    +----------------+
+ *    |       (2)      |
+ *    | 192.168.0.0/24 |
+ *    |    value: 2    |
+ *    |   [0]    [1]   |
+ *    +----------------+
+ *
+ * The child[1] slot of (1) could be filled with another node which has bit #17
+ * (the next bit after the ones that (1) matches on) set to 1. For instance,
+ * 192.168.128.0/24:
+ *
+ *              +----------------+
+ *              |       (1)  (R) |
+ *              | 192.168.0.0/16 |
+ *              |    value: 1    |
+ *              |   [0]    [1]   |
+ *              +----------------+
+ *                   |      |
+ *    +----------------+  +------------------+
+ *    |       (2)      |  |        (3)       |
+ *    | 192.168.0.0/24 |  | 192.168.128.0/24 |
+ *    |    value: 2    |  |     value: 3     |
+ *    |   [0]    [1]   |  |    [0]    [1]    |
+ *    +----------------+  +------------------+
+ *
+ * Let's add another node (4) to the game for 192.168.1.0/24. In order to place
+ * it, node (1) is looked at first, and because (4) of the semantics laid out
+ * above (bit #17 is 0), it would normally be attached to (1) as child[0].
+ * However, that slot is already allocated, so a new node is needed in between.
+ * That node does not have a value attached to it and it will never be
+ * returned to users as result of a lookup. It is only there to differentiate
+ * the traversal further. It will get a prefix as wide as necessary to
+ * distinguish its two children:
+ *
+ *                      +----------------+
+ *                      |       (1)  (R) |
+ *                      | 192.168.0.0/16 |
+ *                      |    value: 1    |
+ *                      |   [0]    [1]   |
+ *                      +----------------+
+ *                           |      |
+ *            +----------------+  +------------------+
+ *            |       (4)  (I) |  |        (3)       |
+ *            | 192.168.0.0/23 |  | 192.168.128.0/24 |
+ *            |    value: ---  |  |     value: 3     |
+ *            |   [0]    [1]   |  |    [0]    [1]    |
+ *            +----------------+  +------------------+
+ *                 |      |
+ *  +----------------+  +----------------+
+ *  |       (2)      |  |       (5)      |
+ *  | 192.168.0.0/24 |  | 192.168.1.0/24 |
+ *  |    value: 2    |  |     value: 5   |
+ *  |   [0]    [1]   |  |   [0]    [1]   |
+ *  +----------------+  +----------------+
+ *
+ * 192.168.1.1/32 would be a child of (5) etc.
+ *
+ * An intermediate node will be turned into a 'real' node on demand. In the
+ * example above, (4) would be re-used if 192.168.0.0/23 is added to the trie.
+ *
+ * A fully populated trie would have a height of 32 nodes, as the trie was
+ * created with a prefix length of 32.
+ *
+ * The lookup starts at the root node. If the current node matches and if there
+ * is a child that can be used to become more specific, the trie is traversed
+ * downwards. The last node in the traversal that is a non-intermediate one is
+ * returned.
+ */
+
+static inline int extract_bit(const u8 *data, size_t index)
+{
+	return !!(data[index / 8] & (1 << (7 - (index % 8))));
+}
+
+/**
+ * longest_prefix_match() - determine the longest prefix
+ * @trie:	The trie to get internal sizes from
+ * @node:	The node to operate on
+ * @key:	The key to compare to @node
+ *
+ * Determine the longest prefix of @node that matches the bits in @key.
+ */
+static size_t longest_prefix_match(const struct lpm_trie *trie,
+				   const struct lpm_trie_node *node,
+				   const struct bpf_lpm_trie_key *key)
+{
+	u32 limit = min(node->prefixlen, key->prefixlen);
+	u32 prefixlen = 0, i = 0;
+
+	BUILD_BUG_ON(offsetof(struct lpm_trie_node, data) % sizeof(u32));
+	BUILD_BUG_ON(offsetof(struct bpf_lpm_trie_key, data) % sizeof(u32));
+
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(CONFIG_64BIT)
+
+	/* data_size >= 16 has very small probability.
+	 * We do not use a loop for optimal code generation.
+	 */
+	if (trie->data_size >= 8) {
+		u64 diff = be64_to_cpu(*(__be64 *)node->data ^
+				       *(__be64 *)key->data);
+
+		prefixlen = 64 - fls64(diff);
+		if (prefixlen >= limit)
+			return limit;
+		if (diff)
+			return prefixlen;
+		i = 8;
+	}
+#endif
+
+	while (trie->data_size >= i + 4) {
+		u32 diff = be32_to_cpu(*(__be32 *)&node->data[i] ^
+				       *(__be32 *)&key->data[i]);
+
+		prefixlen += 32 - fls(diff);
+		if (prefixlen >= limit)
+			return limit;
+		if (diff)
+			return prefixlen;
+		i += 4;
+	}
+
+	if (trie->data_size >= i + 2) {
+		u16 diff = be16_to_cpu(*(__be16 *)&node->data[i] ^
+				       *(__be16 *)&key->data[i]);
+
+		prefixlen += 16 - fls(diff);
+		if (prefixlen >= limit)
+			return limit;
+		if (diff)
+			return prefixlen;
+		i += 2;
+	}
+
+	if (trie->data_size >= i + 1) {
+		prefixlen += 8 - fls(node->data[i] ^ key->data[i]);
+
+		if (prefixlen >= limit)
+			return limit;
+	}
+
+	return prefixlen;
+}
+
+/* Called from syscall or from eBPF program */
+static void *trie_lookup_elem(struct bpf_map *map, void *_key)
+{
+	struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+	struct lpm_trie_node *node, *found = NULL;
+	struct bpf_lpm_trie_key *key = _key;
+
+	if (key->prefixlen > trie->max_prefixlen)
+		return NULL;
+
+	/* Start walking the trie from the root node ... */
+
+	for (node = rcu_dereference(trie->root); node;) {
+		unsigned int next_bit;
+		size_t matchlen;
+
+		/* Determine the longest prefix of @node that matches @key.
+		 * If it's the maximum possible prefix for this trie, we have
+		 * an exact match and can return it directly.
+		 */
+		matchlen = longest_prefix_match(trie, node, key);
+		if (matchlen == trie->max_prefixlen) {
+			found = node;
+			break;
+		}
+
+		/* If the number of bits that match is smaller than the prefix
+		 * length of @node, bail out and return the node we have seen
+		 * last in the traversal (ie, the parent).
+		 */
+		if (matchlen < node->prefixlen)
+			break;
+
+		/* Consider this node as return candidate unless it is an
+		 * artificially added intermediate one.
+		 */
+		if (!(node->flags & LPM_TREE_NODE_FLAG_IM))
+			found = node;
+
+		/* If the node match is fully satisfied, let's see if we can
+		 * become more specific. Determine the next bit in the key and
+		 * traverse down.
+		 */
+		next_bit = extract_bit(key->data, node->prefixlen);
+		node = rcu_dereference(node->child[next_bit]);
+	}
+
+	if (!found)
+		return NULL;
+
+	return found->data + trie->data_size;
+}
+
+static struct lpm_trie_node *lpm_trie_node_alloc(const struct lpm_trie *trie,
+						 const void *value)
+{
+	struct lpm_trie_node *node;
+	size_t size = sizeof(struct lpm_trie_node) + trie->data_size;
+
+	if (value)
+		size += trie->map.value_size;
+
+	node = kmalloc_node(size, GFP_ATOMIC | __GFP_NOWARN,
+			    trie->map.numa_node);
+	if (!node)
+		return NULL;
+
+	node->flags = 0;
+
+	if (value)
+		memcpy(node->data + trie->data_size, value,
+		       trie->map.value_size);
+
+	return node;
+}
+
+/* Called from syscall or from eBPF program */
+static int trie_update_elem(struct bpf_map *map,
+			    void *_key, void *value, u64 flags)
+{
+	struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+	struct lpm_trie_node *node, *im_node = NULL, *new_node = NULL;
+	struct lpm_trie_node __rcu **slot;
+	struct bpf_lpm_trie_key *key = _key;
+	unsigned long irq_flags;
+	unsigned int next_bit;
+	size_t matchlen = 0;
+	int ret = 0;
+
+	if (unlikely(flags > BPF_EXIST))
+		return -EINVAL;
+
+	if (key->prefixlen > trie->max_prefixlen)
+		return -EINVAL;
+
+	spin_lock_irqsave(&trie->lock, irq_flags);
+
+	/* Allocate and fill a new node */
+
+	if (trie->n_entries == trie->map.max_entries) {
+		ret = -ENOSPC;
+		goto out;
+	}
+
+	new_node = lpm_trie_node_alloc(trie, value);
+	if (!new_node) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	trie->n_entries++;
+
+	new_node->prefixlen = key->prefixlen;
+	RCU_INIT_POINTER(new_node->child[0], NULL);
+	RCU_INIT_POINTER(new_node->child[1], NULL);
+	memcpy(new_node->data, key->data, trie->data_size);
+
+	/* Now find a slot to attach the new node. To do that, walk the tree
+	 * from the root and match as many bits as possible for each node until
+	 * we either find an empty slot or a slot that needs to be replaced by
+	 * an intermediate node.
+	 */
+	slot = &trie->root;
+
+	while ((node = rcu_dereference_protected(*slot,
+					lockdep_is_held(&trie->lock)))) {
+		matchlen = longest_prefix_match(trie, node, key);
+
+		if (node->prefixlen != matchlen ||
+		    node->prefixlen == key->prefixlen ||
+		    node->prefixlen == trie->max_prefixlen)
+			break;
+
+		next_bit = extract_bit(key->data, node->prefixlen);
+		slot = &node->child[next_bit];
+	}
+
+	/* If the slot is empty (a free child pointer or an empty root),
+	 * simply assign the @new_node to that slot and be done.
+	 */
+	if (!node) {
+		rcu_assign_pointer(*slot, new_node);
+		goto out;
+	}
+
+	/* If the slot we picked already exists, replace it with @new_node
+	 * which already has the correct data array set.
+	 */
+	if (node->prefixlen == matchlen) {
+		new_node->child[0] = node->child[0];
+		new_node->child[1] = node->child[1];
+
+		if (!(node->flags & LPM_TREE_NODE_FLAG_IM))
+			trie->n_entries--;
+
+		rcu_assign_pointer(*slot, new_node);
+		kfree_rcu(node, rcu);
+
+		goto out;
+	}
+
+	/* If the new node matches the prefix completely, it must be inserted
+	 * as an ancestor. Simply insert it between @node and *@slot.
+	 */
+	if (matchlen == key->prefixlen) {
+		next_bit = extract_bit(node->data, matchlen);
+		rcu_assign_pointer(new_node->child[next_bit], node);
+		rcu_assign_pointer(*slot, new_node);
+		goto out;
+	}
+
+	im_node = lpm_trie_node_alloc(trie, NULL);
+	if (!im_node) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	im_node->prefixlen = matchlen;
+	im_node->flags |= LPM_TREE_NODE_FLAG_IM;
+	memcpy(im_node->data, node->data, trie->data_size);
+
+	/* Now determine which child to install in which slot */
+	if (extract_bit(key->data, matchlen)) {
+		rcu_assign_pointer(im_node->child[0], node);
+		rcu_assign_pointer(im_node->child[1], new_node);
+	} else {
+		rcu_assign_pointer(im_node->child[0], new_node);
+		rcu_assign_pointer(im_node->child[1], node);
+	}
+
+	/* Finally, assign the intermediate node to the determined spot */
+	rcu_assign_pointer(*slot, im_node);
+
+out:
+	if (ret) {
+		if (new_node)
+			trie->n_entries--;
+
+		kfree(new_node);
+		kfree(im_node);
+	}
+
+	spin_unlock_irqrestore(&trie->lock, irq_flags);
+
+	return ret;
+}
+
+/* Called from syscall or from eBPF program */
+static int trie_delete_elem(struct bpf_map *map, void *_key)
+{
+	struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+	struct bpf_lpm_trie_key *key = _key;
+	struct lpm_trie_node __rcu **trim, **trim2;
+	struct lpm_trie_node *node, *parent;
+	unsigned long irq_flags;
+	unsigned int next_bit;
+	size_t matchlen = 0;
+	int ret = 0;
+
+	if (key->prefixlen > trie->max_prefixlen)
+		return -EINVAL;
+
+	spin_lock_irqsave(&trie->lock, irq_flags);
+
+	/* Walk the tree looking for an exact key/length match and keeping
+	 * track of the path we traverse.  We will need to know the node
+	 * we wish to delete, and the slot that points to the node we want
+	 * to delete.  We may also need to know the nodes parent and the
+	 * slot that contains it.
+	 */
+	trim = &trie->root;
+	trim2 = trim;
+	parent = NULL;
+	while ((node = rcu_dereference_protected(
+		       *trim, lockdep_is_held(&trie->lock)))) {
+		matchlen = longest_prefix_match(trie, node, key);
+
+		if (node->prefixlen != matchlen ||
+		    node->prefixlen == key->prefixlen)
+			break;
+
+		parent = node;
+		trim2 = trim;
+		next_bit = extract_bit(key->data, node->prefixlen);
+		trim = &node->child[next_bit];
+	}
+
+	if (!node || node->prefixlen != key->prefixlen ||
+	    node->prefixlen != matchlen ||
+	    (node->flags & LPM_TREE_NODE_FLAG_IM)) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	trie->n_entries--;
+
+	/* If the node we are removing has two children, simply mark it
+	 * as intermediate and we are done.
+	 */
+	if (rcu_access_pointer(node->child[0]) &&
+	    rcu_access_pointer(node->child[1])) {
+		node->flags |= LPM_TREE_NODE_FLAG_IM;
+		goto out;
+	}
+
+	/* If the parent of the node we are about to delete is an intermediate
+	 * node, and the deleted node doesn't have any children, we can delete
+	 * the intermediate parent as well and promote its other child
+	 * up the tree.  Doing this maintains the invariant that all
+	 * intermediate nodes have exactly 2 children and that there are no
+	 * unnecessary intermediate nodes in the tree.
+	 */
+	if (parent && (parent->flags & LPM_TREE_NODE_FLAG_IM) &&
+	    !node->child[0] && !node->child[1]) {
+		if (node == rcu_access_pointer(parent->child[0]))
+			rcu_assign_pointer(
+				*trim2, rcu_access_pointer(parent->child[1]));
+		else
+			rcu_assign_pointer(
+				*trim2, rcu_access_pointer(parent->child[0]));
+		kfree_rcu(parent, rcu);
+		kfree_rcu(node, rcu);
+		goto out;
+	}
+
+	/* The node we are removing has either zero or one child. If there
+	 * is a child, move it into the removed node's slot then delete
+	 * the node.  Otherwise just clear the slot and delete the node.
+	 */
+	if (node->child[0])
+		rcu_assign_pointer(*trim, rcu_access_pointer(node->child[0]));
+	else if (node->child[1])
+		rcu_assign_pointer(*trim, rcu_access_pointer(node->child[1]));
+	else
+		RCU_INIT_POINTER(*trim, NULL);
+	kfree_rcu(node, rcu);
+
+out:
+	spin_unlock_irqrestore(&trie->lock, irq_flags);
+
+	return ret;
+}
+
+#define LPM_DATA_SIZE_MAX	256
+#define LPM_DATA_SIZE_MIN	1
+
+#define LPM_VAL_SIZE_MAX	(KMALLOC_MAX_SIZE - LPM_DATA_SIZE_MAX - \
+				 sizeof(struct lpm_trie_node))
+#define LPM_VAL_SIZE_MIN	1
+
+#define LPM_KEY_SIZE(X)		(sizeof(struct bpf_lpm_trie_key) + (X))
+#define LPM_KEY_SIZE_MAX	LPM_KEY_SIZE(LPM_DATA_SIZE_MAX)
+#define LPM_KEY_SIZE_MIN	LPM_KEY_SIZE(LPM_DATA_SIZE_MIN)
+
+#define LPM_CREATE_FLAG_MASK	(BPF_F_NO_PREALLOC | BPF_F_NUMA_NODE |	\
+				 BPF_F_ACCESS_MASK)
+
+static struct bpf_map *trie_alloc(union bpf_attr *attr)
+{
+	struct lpm_trie *trie;
+	u64 cost = sizeof(*trie), cost_per_node;
+	int ret;
+
+	if (!bpf_capable())
+		return ERR_PTR(-EPERM);
+
+	/* check sanity of attributes */
+	if (attr->max_entries == 0 ||
+	    !(attr->map_flags & BPF_F_NO_PREALLOC) ||
+	    attr->map_flags & ~LPM_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags) ||
+	    attr->key_size < LPM_KEY_SIZE_MIN ||
+	    attr->key_size > LPM_KEY_SIZE_MAX ||
+	    attr->value_size < LPM_VAL_SIZE_MIN ||
+	    attr->value_size > LPM_VAL_SIZE_MAX)
+		return ERR_PTR(-EINVAL);
+
+	trie = kzalloc(sizeof(*trie), GFP_USER | __GFP_NOWARN);
+	if (!trie)
+		return ERR_PTR(-ENOMEM);
+
+	/* copy mandatory map attributes */
+	bpf_map_init_from_attr(&trie->map, attr);
+	trie->data_size = attr->key_size -
+			  offsetof(struct bpf_lpm_trie_key, data);
+	trie->max_prefixlen = trie->data_size * 8;
+
+	cost_per_node = sizeof(struct lpm_trie_node) +
+			attr->value_size + trie->data_size;
+	cost += (u64) attr->max_entries * cost_per_node;
+
+	ret = bpf_map_charge_init(&trie->map.memory, cost);
+	if (ret)
+		goto out_err;
+
+	spin_lock_init(&trie->lock);
+
+	return &trie->map;
+out_err:
+	kfree(trie);
+	return ERR_PTR(ret);
+}
+
+static void trie_free(struct bpf_map *map)
+{
+	struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+	struct lpm_trie_node __rcu **slot;
+	struct lpm_trie_node *node;
+
+	/* Always start at the root and walk down to a node that has no
+	 * children. Then free that node, nullify its reference in the parent
+	 * and start over.
+	 */
+
+	for (;;) {
+		slot = &trie->root;
+
+		for (;;) {
+			node = rcu_dereference_protected(*slot, 1);
+			if (!node)
+				goto out;
+
+			if (rcu_access_pointer(node->child[0])) {
+				slot = &node->child[0];
+				continue;
+			}
+
+			if (rcu_access_pointer(node->child[1])) {
+				slot = &node->child[1];
+				continue;
+			}
+
+			kfree(node);
+			RCU_INIT_POINTER(*slot, NULL);
+			break;
+		}
+	}
+
+out:
+	kfree(trie);
+}
+
+static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key)
+{
+	struct lpm_trie_node *node, *next_node = NULL, *parent, *search_root;
+	struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+	struct bpf_lpm_trie_key *key = _key, *next_key = _next_key;
+	struct lpm_trie_node **node_stack = NULL;
+	int err = 0, stack_ptr = -1;
+	unsigned int next_bit;
+	size_t matchlen;
+
+	/* The get_next_key follows postorder. For the 4 node example in
+	 * the top of this file, the trie_get_next_key() returns the following
+	 * one after another:
+	 *   192.168.0.0/24
+	 *   192.168.1.0/24
+	 *   192.168.128.0/24
+	 *   192.168.0.0/16
+	 *
+	 * The idea is to return more specific keys before less specific ones.
+	 */
+
+	/* Empty trie */
+	search_root = rcu_dereference(trie->root);
+	if (!search_root)
+		return -ENOENT;
+
+	/* For invalid key, find the leftmost node in the trie */
+	if (!key || key->prefixlen > trie->max_prefixlen)
+		goto find_leftmost;
+
+	node_stack = kmalloc_array(trie->max_prefixlen,
+				   sizeof(struct lpm_trie_node *),
+				   GFP_ATOMIC | __GFP_NOWARN);
+	if (!node_stack)
+		return -ENOMEM;
+
+	/* Try to find the exact node for the given key */
+	for (node = search_root; node;) {
+		node_stack[++stack_ptr] = node;
+		matchlen = longest_prefix_match(trie, node, key);
+		if (node->prefixlen != matchlen ||
+		    node->prefixlen == key->prefixlen)
+			break;
+
+		next_bit = extract_bit(key->data, node->prefixlen);
+		node = rcu_dereference(node->child[next_bit]);
+	}
+	if (!node || node->prefixlen != key->prefixlen ||
+	    (node->flags & LPM_TREE_NODE_FLAG_IM))
+		goto find_leftmost;
+
+	/* The node with the exactly-matching key has been found,
+	 * find the first node in postorder after the matched node.
+	 */
+	node = node_stack[stack_ptr];
+	while (stack_ptr > 0) {
+		parent = node_stack[stack_ptr - 1];
+		if (rcu_dereference(parent->child[0]) == node) {
+			search_root = rcu_dereference(parent->child[1]);
+			if (search_root)
+				goto find_leftmost;
+		}
+		if (!(parent->flags & LPM_TREE_NODE_FLAG_IM)) {
+			next_node = parent;
+			goto do_copy;
+		}
+
+		node = parent;
+		stack_ptr--;
+	}
+
+	/* did not find anything */
+	err = -ENOENT;
+	goto free_stack;
+
+find_leftmost:
+	/* Find the leftmost non-intermediate node, all intermediate nodes
+	 * have exact two children, so this function will never return NULL.
+	 */
+	for (node = search_root; node;) {
+		if (node->flags & LPM_TREE_NODE_FLAG_IM) {
+			node = rcu_dereference(node->child[0]);
+		} else {
+			next_node = node;
+			node = rcu_dereference(node->child[0]);
+			if (!node)
+				node = rcu_dereference(next_node->child[1]);
+		}
+	}
+do_copy:
+	next_key->prefixlen = next_node->prefixlen;
+	memcpy((void *)next_key + offsetof(struct bpf_lpm_trie_key, data),
+	       next_node->data, trie->data_size);
+free_stack:
+	kfree(node_stack);
+	return err;
+}
+
+static int trie_check_btf(const struct bpf_map *map,
+			  const struct btf *btf,
+			  const struct btf_type *key_type,
+			  const struct btf_type *value_type)
+{
+	/* Keys must have struct bpf_lpm_trie_key embedded. */
+	return BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ?
+	       -EINVAL : 0;
+}
+
+static int trie_map_btf_id;
+const struct bpf_map_ops trie_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc = trie_alloc,
+	.map_free = trie_free,
+	.map_get_next_key = trie_get_next_key,
+	.map_lookup_elem = trie_lookup_elem,
+	.map_update_elem = trie_update_elem,
+	.map_delete_elem = trie_delete_elem,
+	.map_check_btf = trie_check_btf,
+	.map_btf_name = "lpm_trie",
+	.map_btf_id = &trie_map_btf_id,
+};
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c
new file mode 100644
index 000000000..39ab0b68c
--- /dev/null
+++ b/kernel/bpf/map_in_map.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Facebook
+ */
+#include <linux/slab.h>
+#include <linux/bpf.h>
+
+#include "map_in_map.h"
+
+struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
+{
+	struct bpf_map *inner_map, *inner_map_meta;
+	u32 inner_map_meta_size;
+	struct fd f;
+
+	f = fdget(inner_map_ufd);
+	inner_map = __bpf_map_get(f);
+	if (IS_ERR(inner_map))
+		return inner_map;
+
+	/* Does not support >1 level map-in-map */
+	if (inner_map->inner_map_meta) {
+		fdput(f);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!inner_map->ops->map_meta_equal) {
+		fdput(f);
+		return ERR_PTR(-ENOTSUPP);
+	}
+
+	if (map_value_has_spin_lock(inner_map)) {
+		fdput(f);
+		return ERR_PTR(-ENOTSUPP);
+	}
+
+	inner_map_meta_size = sizeof(*inner_map_meta);
+	/* In some cases verifier needs to access beyond just base map. */
+	if (inner_map->ops == &array_map_ops)
+		inner_map_meta_size = sizeof(struct bpf_array);
+
+	inner_map_meta = kzalloc(inner_map_meta_size, GFP_USER);
+	if (!inner_map_meta) {
+		fdput(f);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	inner_map_meta->map_type = inner_map->map_type;
+	inner_map_meta->key_size = inner_map->key_size;
+	inner_map_meta->value_size = inner_map->value_size;
+	inner_map_meta->map_flags = inner_map->map_flags;
+	inner_map_meta->max_entries = inner_map->max_entries;
+	inner_map_meta->spin_lock_off = inner_map->spin_lock_off;
+
+	/* Misc members not needed in bpf_map_meta_equal() check. */
+	inner_map_meta->ops = inner_map->ops;
+	if (inner_map->ops == &array_map_ops) {
+		inner_map_meta->bypass_spec_v1 = inner_map->bypass_spec_v1;
+		container_of(inner_map_meta, struct bpf_array, map)->index_mask =
+		     container_of(inner_map, struct bpf_array, map)->index_mask;
+	}
+
+	fdput(f);
+	return inner_map_meta;
+}
+
+void bpf_map_meta_free(struct bpf_map *map_meta)
+{
+	kfree(map_meta);
+}
+
+bool bpf_map_meta_equal(const struct bpf_map *meta0,
+			const struct bpf_map *meta1)
+{
+	/* No need to compare ops because it is covered by map_type */
+	return meta0->map_type == meta1->map_type &&
+		meta0->key_size == meta1->key_size &&
+		meta0->value_size == meta1->value_size &&
+		meta0->map_flags == meta1->map_flags;
+}
+
+void *bpf_map_fd_get_ptr(struct bpf_map *map,
+			 struct file *map_file /* not used */,
+			 int ufd)
+{
+	struct bpf_map *inner_map, *inner_map_meta;
+	struct fd f;
+
+	f = fdget(ufd);
+	inner_map = __bpf_map_get(f);
+	if (IS_ERR(inner_map))
+		return inner_map;
+
+	inner_map_meta = map->inner_map_meta;
+	if (inner_map_meta->ops->map_meta_equal(inner_map_meta, inner_map))
+		bpf_map_inc(inner_map);
+	else
+		inner_map = ERR_PTR(-EINVAL);
+
+	fdput(f);
+	return inner_map;
+}
+
+void bpf_map_fd_put_ptr(void *ptr)
+{
+	/* ptr->ops->map_free() has to go through one
+	 * rcu grace period by itself.
+	 */
+	bpf_map_put(ptr);
+}
+
+u32 bpf_map_fd_sys_lookup_elem(void *ptr)
+{
+	return ((struct bpf_map *)ptr)->id;
+}
diff --git a/kernel/bpf/map_in_map.h b/kernel/bpf/map_in_map.h
new file mode 100644
index 000000000..bcb7534af
--- /dev/null
+++ b/kernel/bpf/map_in_map.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2017 Facebook
+ */
+#ifndef __MAP_IN_MAP_H__
+#define __MAP_IN_MAP_H__
+
+#include <linux/types.h>
+
+struct file;
+struct bpf_map;
+
+struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd);
+void bpf_map_meta_free(struct bpf_map *map_meta);
+void *bpf_map_fd_get_ptr(struct bpf_map *map, struct file *map_file,
+			 int ufd);
+void bpf_map_fd_put_ptr(void *ptr);
+u32 bpf_map_fd_sys_lookup_elem(void *ptr);
+
+#endif
diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
new file mode 100644
index 000000000..6a9542af4
--- /dev/null
+++ b/kernel/bpf/map_iter.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 Facebook */
+#include <linux/bpf.h>
+#include <linux/fs.h>
+#include <linux/filter.h>
+#include <linux/kernel.h>
+#include <linux/btf_ids.h>
+
+struct bpf_iter_seq_map_info {
+	u32 map_id;
+};
+
+static void *bpf_map_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_map_info *info = seq->private;
+	struct bpf_map *map;
+
+	map = bpf_map_get_curr_or_next(&info->map_id);
+	if (!map)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	return map;
+}
+
+static void *bpf_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_map_info *info = seq->private;
+
+	++*pos;
+	++info->map_id;
+	bpf_map_put((struct bpf_map *)v);
+	return bpf_map_get_curr_or_next(&info->map_id);
+}
+
+struct bpf_iter__bpf_map {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct bpf_map *, map);
+};
+
+DEFINE_BPF_ITER_FUNC(bpf_map, struct bpf_iter_meta *meta, struct bpf_map *map)
+
+static int __bpf_map_seq_show(struct seq_file *seq, void *v, bool in_stop)
+{
+	struct bpf_iter__bpf_map ctx;
+	struct bpf_iter_meta meta;
+	struct bpf_prog *prog;
+	int ret = 0;
+
+	ctx.meta = &meta;
+	ctx.map = v;
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, in_stop);
+	if (prog)
+		ret = bpf_iter_run_prog(prog, &ctx);
+
+	return ret;
+}
+
+static int bpf_map_seq_show(struct seq_file *seq, void *v)
+{
+	return __bpf_map_seq_show(seq, v, false);
+}
+
+static void bpf_map_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__bpf_map_seq_show(seq, v, true);
+	else
+		bpf_map_put((struct bpf_map *)v);
+}
+
+static const struct seq_operations bpf_map_seq_ops = {
+	.start	= bpf_map_seq_start,
+	.next	= bpf_map_seq_next,
+	.stop	= bpf_map_seq_stop,
+	.show	= bpf_map_seq_show,
+};
+
+BTF_ID_LIST(btf_bpf_map_id)
+BTF_ID(struct, bpf_map)
+
+static const struct bpf_iter_seq_info bpf_map_seq_info = {
+	.seq_ops		= &bpf_map_seq_ops,
+	.init_seq_private	= NULL,
+	.fini_seq_private	= NULL,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_map_info),
+};
+
+static struct bpf_iter_reg bpf_map_reg_info = {
+	.target			= "bpf_map",
+	.ctx_arg_info_size	= 1,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__bpf_map, map),
+		  PTR_TO_BTF_ID_OR_NULL },
+	},
+	.seq_info		= &bpf_map_seq_info,
+};
+
+static int bpf_iter_attach_map(struct bpf_prog *prog,
+			       union bpf_iter_link_info *linfo,
+			       struct bpf_iter_aux_info *aux)
+{
+	u32 key_acc_size, value_acc_size, key_size, value_size;
+	struct bpf_map *map;
+	bool is_percpu = false;
+	int err = -EINVAL;
+
+	if (!linfo->map.map_fd)
+		return -EBADF;
+
+	map = bpf_map_get_with_uref(linfo->map.map_fd);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
+		is_percpu = true;
+	else if (map->map_type != BPF_MAP_TYPE_HASH &&
+		 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
+		 map->map_type != BPF_MAP_TYPE_ARRAY)
+		goto put_map;
+
+	key_acc_size = prog->aux->max_rdonly_access;
+	value_acc_size = prog->aux->max_rdwr_access;
+	key_size = map->key_size;
+	if (!is_percpu)
+		value_size = map->value_size;
+	else
+		value_size = round_up(map->value_size, 8) * num_possible_cpus();
+
+	if (key_acc_size > key_size || value_acc_size > value_size) {
+		err = -EACCES;
+		goto put_map;
+	}
+
+	aux->map = map;
+	return 0;
+
+put_map:
+	bpf_map_put_with_uref(map);
+	return err;
+}
+
+static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
+{
+	bpf_map_put_with_uref(aux->map);
+}
+
+void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,
+			      struct seq_file *seq)
+{
+	seq_printf(seq, "map_id:\t%u\n", aux->map->id);
+}
+
+int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,
+				struct bpf_link_info *info)
+{
+	info->iter.map.map_id = aux->map->id;
+	return 0;
+}
+
+DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta,
+		     struct bpf_map *map, void *key, void *value)
+
+static const struct bpf_iter_reg bpf_map_elem_reg_info = {
+	.target			= "bpf_map_elem",
+	.attach_target		= bpf_iter_attach_map,
+	.detach_target		= bpf_iter_detach_map,
+	.show_fdinfo		= bpf_iter_map_show_fdinfo,
+	.fill_link_info		= bpf_iter_map_fill_link_info,
+	.ctx_arg_info_size	= 2,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__bpf_map_elem, key),
+		  PTR_TO_RDONLY_BUF_OR_NULL },
+		{ offsetof(struct bpf_iter__bpf_map_elem, value),
+		  PTR_TO_RDWR_BUF_OR_NULL },
+	},
+};
+
+static int __init bpf_map_iter_init(void)
+{
+	int ret;
+
+	bpf_map_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_map_id;
+	ret = bpf_iter_reg_target(&bpf_map_reg_info);
+	if (ret)
+		return ret;
+
+	return bpf_iter_reg_target(&bpf_map_elem_reg_info);
+}
+
+late_initcall(bpf_map_iter_init);
diff --git a/kernel/bpf/net_namespace.c b/kernel/bpf/net_namespace.c
new file mode 100644
index 000000000..542f275bf
--- /dev/null
+++ b/kernel/bpf/net_namespace.c
@@ -0,0 +1,566 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <net/net_namespace.h>
+
+/*
+ * Functions to manage BPF programs attached to netns
+ */
+
+struct bpf_netns_link {
+	struct bpf_link	link;
+	enum bpf_attach_type type;
+	enum netns_bpf_attach_type netns_type;
+
+	/* We don't hold a ref to net in order to auto-detach the link
+	 * when netns is going away. Instead we rely on pernet
+	 * pre_exit callback to clear this pointer. Must be accessed
+	 * with netns_bpf_mutex held.
+	 */
+	struct net *net;
+	struct list_head node; /* node in list of links attached to net */
+};
+
+/* Protects updates to netns_bpf */
+DEFINE_MUTEX(netns_bpf_mutex);
+
+static void netns_bpf_attach_type_unneed(enum netns_bpf_attach_type type)
+{
+	switch (type) {
+#ifdef CONFIG_INET
+	case NETNS_BPF_SK_LOOKUP:
+		static_branch_dec(&bpf_sk_lookup_enabled);
+		break;
+#endif
+	default:
+		break;
+	}
+}
+
+static void netns_bpf_attach_type_need(enum netns_bpf_attach_type type)
+{
+	switch (type) {
+#ifdef CONFIG_INET
+	case NETNS_BPF_SK_LOOKUP:
+		static_branch_inc(&bpf_sk_lookup_enabled);
+		break;
+#endif
+	default:
+		break;
+	}
+}
+
+/* Must be called with netns_bpf_mutex held. */
+static void netns_bpf_run_array_detach(struct net *net,
+				       enum netns_bpf_attach_type type)
+{
+	struct bpf_prog_array *run_array;
+
+	run_array = rcu_replace_pointer(net->bpf.run_array[type], NULL,
+					lockdep_is_held(&netns_bpf_mutex));
+	bpf_prog_array_free(run_array);
+}
+
+static int link_index(struct net *net, enum netns_bpf_attach_type type,
+		      struct bpf_netns_link *link)
+{
+	struct bpf_netns_link *pos;
+	int i = 0;
+
+	list_for_each_entry(pos, &net->bpf.links[type], node) {
+		if (pos == link)
+			return i;
+		i++;
+	}
+	return -ENOENT;
+}
+
+static int link_count(struct net *net, enum netns_bpf_attach_type type)
+{
+	struct list_head *pos;
+	int i = 0;
+
+	list_for_each(pos, &net->bpf.links[type])
+		i++;
+	return i;
+}
+
+static void fill_prog_array(struct net *net, enum netns_bpf_attach_type type,
+			    struct bpf_prog_array *prog_array)
+{
+	struct bpf_netns_link *pos;
+	unsigned int i = 0;
+
+	list_for_each_entry(pos, &net->bpf.links[type], node) {
+		prog_array->items[i].prog = pos->link.prog;
+		i++;
+	}
+}
+
+static void bpf_netns_link_release(struct bpf_link *link)
+{
+	struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+	enum netns_bpf_attach_type type = net_link->netns_type;
+	struct bpf_prog_array *old_array, *new_array;
+	struct net *net;
+	int cnt, idx;
+
+	mutex_lock(&netns_bpf_mutex);
+
+	/* We can race with cleanup_net, but if we see a non-NULL
+	 * struct net pointer, pre_exit has not run yet and wait for
+	 * netns_bpf_mutex.
+	 */
+	net = net_link->net;
+	if (!net)
+		goto out_unlock;
+
+	/* Mark attach point as unused */
+	netns_bpf_attach_type_unneed(type);
+
+	/* Remember link position in case of safe delete */
+	idx = link_index(net, type, net_link);
+	list_del(&net_link->node);
+
+	cnt = link_count(net, type);
+	if (!cnt) {
+		netns_bpf_run_array_detach(net, type);
+		goto out_unlock;
+	}
+
+	old_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	new_array = bpf_prog_array_alloc(cnt, GFP_KERNEL);
+	if (!new_array) {
+		WARN_ON(bpf_prog_array_delete_safe_at(old_array, idx));
+		goto out_unlock;
+	}
+	fill_prog_array(net, type, new_array);
+	rcu_assign_pointer(net->bpf.run_array[type], new_array);
+	bpf_prog_array_free(old_array);
+
+out_unlock:
+	net_link->net = NULL;
+	mutex_unlock(&netns_bpf_mutex);
+}
+
+static int bpf_netns_link_detach(struct bpf_link *link)
+{
+	bpf_netns_link_release(link);
+	return 0;
+}
+
+static void bpf_netns_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+
+	kfree(net_link);
+}
+
+static int bpf_netns_link_update_prog(struct bpf_link *link,
+				      struct bpf_prog *new_prog,
+				      struct bpf_prog *old_prog)
+{
+	struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+	enum netns_bpf_attach_type type = net_link->netns_type;
+	struct bpf_prog_array *run_array;
+	struct net *net;
+	int idx, ret;
+
+	if (old_prog && old_prog != link->prog)
+		return -EPERM;
+	if (new_prog->type != link->prog->type)
+		return -EINVAL;
+
+	mutex_lock(&netns_bpf_mutex);
+
+	net = net_link->net;
+	if (!net || !check_net(net)) {
+		/* Link auto-detached or netns dying */
+		ret = -ENOLINK;
+		goto out_unlock;
+	}
+
+	run_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	idx = link_index(net, type, net_link);
+	ret = bpf_prog_array_update_at(run_array, idx, new_prog);
+	if (ret)
+		goto out_unlock;
+
+	old_prog = xchg(&link->prog, new_prog);
+	bpf_prog_put(old_prog);
+
+out_unlock:
+	mutex_unlock(&netns_bpf_mutex);
+	return ret;
+}
+
+static int bpf_netns_link_fill_info(const struct bpf_link *link,
+				    struct bpf_link_info *info)
+{
+	const struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+	unsigned int inum = 0;
+	struct net *net;
+
+	mutex_lock(&netns_bpf_mutex);
+	net = net_link->net;
+	if (net && check_net(net))
+		inum = net->ns.inum;
+	mutex_unlock(&netns_bpf_mutex);
+
+	info->netns.netns_ino = inum;
+	info->netns.attach_type = net_link->type;
+	return 0;
+}
+
+static void bpf_netns_link_show_fdinfo(const struct bpf_link *link,
+				       struct seq_file *seq)
+{
+	struct bpf_link_info info = {};
+
+	bpf_netns_link_fill_info(link, &info);
+	seq_printf(seq,
+		   "netns_ino:\t%u\n"
+		   "attach_type:\t%u\n",
+		   info.netns.netns_ino,
+		   info.netns.attach_type);
+}
+
+static const struct bpf_link_ops bpf_netns_link_ops = {
+	.release = bpf_netns_link_release,
+	.dealloc = bpf_netns_link_dealloc,
+	.detach = bpf_netns_link_detach,
+	.update_prog = bpf_netns_link_update_prog,
+	.fill_link_info = bpf_netns_link_fill_info,
+	.show_fdinfo = bpf_netns_link_show_fdinfo,
+};
+
+/* Must be called with netns_bpf_mutex held. */
+static int __netns_bpf_prog_query(const union bpf_attr *attr,
+				  union bpf_attr __user *uattr,
+				  struct net *net,
+				  enum netns_bpf_attach_type type)
+{
+	__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
+	struct bpf_prog_array *run_array;
+	u32 prog_cnt = 0, flags = 0;
+
+	run_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	if (run_array)
+		prog_cnt = bpf_prog_array_length(run_array);
+
+	if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
+		return -EFAULT;
+	if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
+		return -EFAULT;
+	if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
+		return 0;
+
+	return bpf_prog_array_copy_to_user(run_array, prog_ids,
+					   attr->query.prog_cnt);
+}
+
+int netns_bpf_prog_query(const union bpf_attr *attr,
+			 union bpf_attr __user *uattr)
+{
+	enum netns_bpf_attach_type type;
+	struct net *net;
+	int ret;
+
+	if (attr->query.query_flags)
+		return -EINVAL;
+
+	type = to_netns_bpf_attach_type(attr->query.attach_type);
+	if (type < 0)
+		return -EINVAL;
+
+	net = get_net_ns_by_fd(attr->query.target_fd);
+	if (IS_ERR(net))
+		return PTR_ERR(net);
+
+	mutex_lock(&netns_bpf_mutex);
+	ret = __netns_bpf_prog_query(attr, uattr, net, type);
+	mutex_unlock(&netns_bpf_mutex);
+
+	put_net(net);
+	return ret;
+}
+
+int netns_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	struct bpf_prog_array *run_array;
+	enum netns_bpf_attach_type type;
+	struct bpf_prog *attached;
+	struct net *net;
+	int ret;
+
+	if (attr->target_fd || attr->attach_flags || attr->replace_bpf_fd)
+		return -EINVAL;
+
+	type = to_netns_bpf_attach_type(attr->attach_type);
+	if (type < 0)
+		return -EINVAL;
+
+	net = current->nsproxy->net_ns;
+	mutex_lock(&netns_bpf_mutex);
+
+	/* Attaching prog directly is not compatible with links */
+	if (!list_empty(&net->bpf.links[type])) {
+		ret = -EEXIST;
+		goto out_unlock;
+	}
+
+	switch (type) {
+	case NETNS_BPF_FLOW_DISSECTOR:
+		ret = flow_dissector_bpf_prog_attach_check(net, prog);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	if (ret)
+		goto out_unlock;
+
+	attached = net->bpf.progs[type];
+	if (attached == prog) {
+		/* The same program cannot be attached twice */
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	run_array = rcu_dereference_protected(net->bpf.run_array[type],
+					      lockdep_is_held(&netns_bpf_mutex));
+	if (run_array) {
+		WRITE_ONCE(run_array->items[0].prog, prog);
+	} else {
+		run_array = bpf_prog_array_alloc(1, GFP_KERNEL);
+		if (!run_array) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		}
+		run_array->items[0].prog = prog;
+		rcu_assign_pointer(net->bpf.run_array[type], run_array);
+	}
+
+	net->bpf.progs[type] = prog;
+	if (attached)
+		bpf_prog_put(attached);
+
+out_unlock:
+	mutex_unlock(&netns_bpf_mutex);
+
+	return ret;
+}
+
+/* Must be called with netns_bpf_mutex held. */
+static int __netns_bpf_prog_detach(struct net *net,
+				   enum netns_bpf_attach_type type,
+				   struct bpf_prog *old)
+{
+	struct bpf_prog *attached;
+
+	/* Progs attached via links cannot be detached */
+	if (!list_empty(&net->bpf.links[type]))
+		return -EINVAL;
+
+	attached = net->bpf.progs[type];
+	if (!attached || attached != old)
+		return -ENOENT;
+	netns_bpf_run_array_detach(net, type);
+	net->bpf.progs[type] = NULL;
+	bpf_prog_put(attached);
+	return 0;
+}
+
+int netns_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
+{
+	enum netns_bpf_attach_type type;
+	struct bpf_prog *prog;
+	int ret;
+
+	if (attr->target_fd)
+		return -EINVAL;
+
+	type = to_netns_bpf_attach_type(attr->attach_type);
+	if (type < 0)
+		return -EINVAL;
+
+	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	mutex_lock(&netns_bpf_mutex);
+	ret = __netns_bpf_prog_detach(current->nsproxy->net_ns, type, prog);
+	mutex_unlock(&netns_bpf_mutex);
+
+	bpf_prog_put(prog);
+
+	return ret;
+}
+
+static int netns_bpf_max_progs(enum netns_bpf_attach_type type)
+{
+	switch (type) {
+	case NETNS_BPF_FLOW_DISSECTOR:
+		return 1;
+	case NETNS_BPF_SK_LOOKUP:
+		return 64;
+	default:
+		return 0;
+	}
+}
+
+static int netns_bpf_link_attach(struct net *net, struct bpf_link *link,
+				 enum netns_bpf_attach_type type)
+{
+	struct bpf_netns_link *net_link =
+		container_of(link, struct bpf_netns_link, link);
+	struct bpf_prog_array *run_array;
+	int cnt, err;
+
+	mutex_lock(&netns_bpf_mutex);
+
+	cnt = link_count(net, type);
+	if (cnt >= netns_bpf_max_progs(type)) {
+		err = -E2BIG;
+		goto out_unlock;
+	}
+	/* Links are not compatible with attaching prog directly */
+	if (net->bpf.progs[type]) {
+		err = -EEXIST;
+		goto out_unlock;
+	}
+
+	switch (type) {
+	case NETNS_BPF_FLOW_DISSECTOR:
+		err = flow_dissector_bpf_prog_attach_check(net, link->prog);
+		break;
+	case NETNS_BPF_SK_LOOKUP:
+		err = 0; /* nothing to check */
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+	if (err)
+		goto out_unlock;
+
+	run_array = bpf_prog_array_alloc(cnt + 1, GFP_KERNEL);
+	if (!run_array) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+
+	list_add_tail(&net_link->node, &net->bpf.links[type]);
+
+	fill_prog_array(net, type, run_array);
+	run_array = rcu_replace_pointer(net->bpf.run_array[type], run_array,
+					lockdep_is_held(&netns_bpf_mutex));
+	bpf_prog_array_free(run_array);
+
+	/* Mark attach point as used */
+	netns_bpf_attach_type_need(type);
+
+out_unlock:
+	mutex_unlock(&netns_bpf_mutex);
+	return err;
+}
+
+int netns_bpf_link_create(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	enum netns_bpf_attach_type netns_type;
+	struct bpf_link_primer link_primer;
+	struct bpf_netns_link *net_link;
+	enum bpf_attach_type type;
+	struct net *net;
+	int err;
+
+	if (attr->link_create.flags)
+		return -EINVAL;
+
+	type = attr->link_create.attach_type;
+	netns_type = to_netns_bpf_attach_type(type);
+	if (netns_type < 0)
+		return -EINVAL;
+
+	net = get_net_ns_by_fd(attr->link_create.target_fd);
+	if (IS_ERR(net))
+		return PTR_ERR(net);
+
+	net_link = kzalloc(sizeof(*net_link), GFP_USER);
+	if (!net_link) {
+		err = -ENOMEM;
+		goto out_put_net;
+	}
+	bpf_link_init(&net_link->link, BPF_LINK_TYPE_NETNS,
+		      &bpf_netns_link_ops, prog);
+	net_link->net = net;
+	net_link->type = type;
+	net_link->netns_type = netns_type;
+
+	err = bpf_link_prime(&net_link->link, &link_primer);
+	if (err) {
+		kfree(net_link);
+		goto out_put_net;
+	}
+
+	err = netns_bpf_link_attach(net, &net_link->link, netns_type);
+	if (err) {
+		bpf_link_cleanup(&link_primer);
+		goto out_put_net;
+	}
+
+	put_net(net);
+	return bpf_link_settle(&link_primer);
+
+out_put_net:
+	put_net(net);
+	return err;
+}
+
+static int __net_init netns_bpf_pernet_init(struct net *net)
+{
+	int type;
+
+	for (type = 0; type < MAX_NETNS_BPF_ATTACH_TYPE; type++)
+		INIT_LIST_HEAD(&net->bpf.links[type]);
+
+	return 0;
+}
+
+static void __net_exit netns_bpf_pernet_pre_exit(struct net *net)
+{
+	enum netns_bpf_attach_type type;
+	struct bpf_netns_link *net_link;
+
+	mutex_lock(&netns_bpf_mutex);
+	for (type = 0; type < MAX_NETNS_BPF_ATTACH_TYPE; type++) {
+		netns_bpf_run_array_detach(net, type);
+		list_for_each_entry(net_link, &net->bpf.links[type], node) {
+			net_link->net = NULL; /* auto-detach link */
+			netns_bpf_attach_type_unneed(type);
+		}
+		if (net->bpf.progs[type])
+			bpf_prog_put(net->bpf.progs[type]);
+	}
+	mutex_unlock(&netns_bpf_mutex);
+}
+
+static struct pernet_operations netns_bpf_pernet_ops __net_initdata = {
+	.init = netns_bpf_pernet_init,
+	.pre_exit = netns_bpf_pernet_pre_exit,
+};
+
+static int __init netns_bpf_init(void)
+{
+	return register_pernet_subsys(&netns_bpf_pernet_ops);
+}
+
+subsys_initcall(netns_bpf_init);
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
new file mode 100644
index 000000000..bd09290e3
--- /dev/null
+++ b/kernel/bpf/offload.c
@@ -0,0 +1,712 @@
+/*
+ * Copyright (C) 2017-2018 Netronome Systems, Inc.
+ *
+ * This software is licensed under the GNU General License Version 2,
+ * June 1991 as shown in the file COPYING in the top-level directory of this
+ * source tree.
+ *
+ * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
+ * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
+ * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
+ * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+ */
+
+#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
+#include <linux/bug.h>
+#include <linux/kdev_t.h>
+#include <linux/list.h>
+#include <linux/lockdep.h>
+#include <linux/netdevice.h>
+#include <linux/printk.h>
+#include <linux/proc_ns.h>
+#include <linux/rhashtable.h>
+#include <linux/rtnetlink.h>
+#include <linux/rwsem.h>
+
+/* Protects offdevs, members of bpf_offload_netdev and offload members
+ * of all progs.
+ * RTNL lock cannot be taken when holding this lock.
+ */
+static DECLARE_RWSEM(bpf_devs_lock);
+
+struct bpf_offload_dev {
+	const struct bpf_prog_offload_ops *ops;
+	struct list_head netdevs;
+	void *priv;
+};
+
+struct bpf_offload_netdev {
+	struct rhash_head l;
+	struct net_device *netdev;
+	struct bpf_offload_dev *offdev;
+	struct list_head progs;
+	struct list_head maps;
+	struct list_head offdev_netdevs;
+};
+
+static const struct rhashtable_params offdevs_params = {
+	.nelem_hint		= 4,
+	.key_len		= sizeof(struct net_device *),
+	.key_offset		= offsetof(struct bpf_offload_netdev, netdev),
+	.head_offset		= offsetof(struct bpf_offload_netdev, l),
+	.automatic_shrinking	= true,
+};
+
+static struct rhashtable offdevs;
+static bool offdevs_inited;
+
+static int bpf_dev_offload_check(struct net_device *netdev)
+{
+	if (!netdev)
+		return -EINVAL;
+	if (!netdev->netdev_ops->ndo_bpf)
+		return -EOPNOTSUPP;
+	return 0;
+}
+
+static struct bpf_offload_netdev *
+bpf_offload_find_netdev(struct net_device *netdev)
+{
+	lockdep_assert_held(&bpf_devs_lock);
+
+	if (!offdevs_inited)
+		return NULL;
+	return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
+}
+
+int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
+{
+	struct bpf_offload_netdev *ondev;
+	struct bpf_prog_offload *offload;
+	int err;
+
+	if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
+	    attr->prog_type != BPF_PROG_TYPE_XDP)
+		return -EINVAL;
+
+	if (attr->prog_flags)
+		return -EINVAL;
+
+	offload = kzalloc(sizeof(*offload), GFP_USER);
+	if (!offload)
+		return -ENOMEM;
+
+	offload->prog = prog;
+
+	offload->netdev = dev_get_by_index(current->nsproxy->net_ns,
+					   attr->prog_ifindex);
+	err = bpf_dev_offload_check(offload->netdev);
+	if (err)
+		goto err_maybe_put;
+
+	down_write(&bpf_devs_lock);
+	ondev = bpf_offload_find_netdev(offload->netdev);
+	if (!ondev) {
+		err = -EINVAL;
+		goto err_unlock;
+	}
+	offload->offdev = ondev->offdev;
+	prog->aux->offload = offload;
+	list_add_tail(&offload->offloads, &ondev->progs);
+	dev_put(offload->netdev);
+	up_write(&bpf_devs_lock);
+
+	return 0;
+err_unlock:
+	up_write(&bpf_devs_lock);
+err_maybe_put:
+	if (offload->netdev)
+		dev_put(offload->netdev);
+	kfree(offload);
+	return err;
+}
+
+int bpf_prog_offload_verifier_prep(struct bpf_prog *prog)
+{
+	struct bpf_prog_offload *offload;
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	offload = prog->aux->offload;
+	if (offload) {
+		ret = offload->offdev->ops->prepare(prog);
+		offload->dev_state = !ret;
+	}
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
+				 int insn_idx, int prev_insn_idx)
+{
+	struct bpf_prog_offload *offload;
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	offload = env->prog->aux->offload;
+	if (offload)
+		ret = offload->offdev->ops->insn_hook(env, insn_idx,
+						      prev_insn_idx);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+int bpf_prog_offload_finalize(struct bpf_verifier_env *env)
+{
+	struct bpf_prog_offload *offload;
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	offload = env->prog->aux->offload;
+	if (offload) {
+		if (offload->offdev->ops->finalize)
+			ret = offload->offdev->ops->finalize(env);
+		else
+			ret = 0;
+	}
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+void
+bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off,
+			      struct bpf_insn *insn)
+{
+	const struct bpf_prog_offload_ops *ops;
+	struct bpf_prog_offload *offload;
+	int ret = -EOPNOTSUPP;
+
+	down_read(&bpf_devs_lock);
+	offload = env->prog->aux->offload;
+	if (offload) {
+		ops = offload->offdev->ops;
+		if (!offload->opt_failed && ops->replace_insn)
+			ret = ops->replace_insn(env, off, insn);
+		offload->opt_failed |= ret;
+	}
+	up_read(&bpf_devs_lock);
+}
+
+void
+bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt)
+{
+	struct bpf_prog_offload *offload;
+	int ret = -EOPNOTSUPP;
+
+	down_read(&bpf_devs_lock);
+	offload = env->prog->aux->offload;
+	if (offload) {
+		if (!offload->opt_failed && offload->offdev->ops->remove_insns)
+			ret = offload->offdev->ops->remove_insns(env, off, cnt);
+		offload->opt_failed |= ret;
+	}
+	up_read(&bpf_devs_lock);
+}
+
+static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
+{
+	struct bpf_prog_offload *offload = prog->aux->offload;
+
+	if (offload->dev_state)
+		offload->offdev->ops->destroy(prog);
+
+	/* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */
+	bpf_prog_free_id(prog, true);
+
+	list_del_init(&offload->offloads);
+	kfree(offload);
+	prog->aux->offload = NULL;
+}
+
+void bpf_prog_offload_destroy(struct bpf_prog *prog)
+{
+	down_write(&bpf_devs_lock);
+	if (prog->aux->offload)
+		__bpf_prog_offload_destroy(prog);
+	up_write(&bpf_devs_lock);
+}
+
+static int bpf_prog_offload_translate(struct bpf_prog *prog)
+{
+	struct bpf_prog_offload *offload;
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	offload = prog->aux->offload;
+	if (offload)
+		ret = offload->offdev->ops->translate(prog);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+static unsigned int bpf_prog_warn_on_exec(const void *ctx,
+					  const struct bpf_insn *insn)
+{
+	WARN(1, "attempt to execute device eBPF program on the host!");
+	return 0;
+}
+
+int bpf_prog_offload_compile(struct bpf_prog *prog)
+{
+	prog->bpf_func = bpf_prog_warn_on_exec;
+
+	return bpf_prog_offload_translate(prog);
+}
+
+struct ns_get_path_bpf_prog_args {
+	struct bpf_prog *prog;
+	struct bpf_prog_info *info;
+};
+
+static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
+{
+	struct ns_get_path_bpf_prog_args *args = private_data;
+	struct bpf_prog_aux *aux = args->prog->aux;
+	struct ns_common *ns;
+	struct net *net;
+
+	rtnl_lock();
+	down_read(&bpf_devs_lock);
+
+	if (aux->offload) {
+		args->info->ifindex = aux->offload->netdev->ifindex;
+		net = dev_net(aux->offload->netdev);
+		get_net(net);
+		ns = &net->ns;
+	} else {
+		args->info->ifindex = 0;
+		ns = NULL;
+	}
+
+	up_read(&bpf_devs_lock);
+	rtnl_unlock();
+
+	return ns;
+}
+
+int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
+			       struct bpf_prog *prog)
+{
+	struct ns_get_path_bpf_prog_args args = {
+		.prog	= prog,
+		.info	= info,
+	};
+	struct bpf_prog_aux *aux = prog->aux;
+	struct inode *ns_inode;
+	struct path ns_path;
+	char __user *uinsns;
+	int res;
+	u32 ulen;
+
+	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
+	if (res) {
+		if (!info->ifindex)
+			return -ENODEV;
+		return res;
+	}
+
+	down_read(&bpf_devs_lock);
+
+	if (!aux->offload) {
+		up_read(&bpf_devs_lock);
+		return -ENODEV;
+	}
+
+	ulen = info->jited_prog_len;
+	info->jited_prog_len = aux->offload->jited_len;
+	if (info->jited_prog_len && ulen) {
+		uinsns = u64_to_user_ptr(info->jited_prog_insns);
+		ulen = min_t(u32, info->jited_prog_len, ulen);
+		if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
+			up_read(&bpf_devs_lock);
+			return -EFAULT;
+		}
+	}
+
+	up_read(&bpf_devs_lock);
+
+	ns_inode = ns_path.dentry->d_inode;
+	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
+	info->netns_ino = ns_inode->i_ino;
+	path_put(&ns_path);
+
+	return 0;
+}
+
+const struct bpf_prog_ops bpf_offload_prog_ops = {
+};
+
+static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
+			       enum bpf_netdev_command cmd)
+{
+	struct netdev_bpf data = {};
+	struct net_device *netdev;
+
+	ASSERT_RTNL();
+
+	data.command = cmd;
+	data.offmap = offmap;
+	/* Caller must make sure netdev is valid */
+	netdev = offmap->netdev;
+
+	return netdev->netdev_ops->ndo_bpf(netdev, &data);
+}
+
+struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
+{
+	struct net *net = current->nsproxy->net_ns;
+	struct bpf_offload_netdev *ondev;
+	struct bpf_offloaded_map *offmap;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return ERR_PTR(-EPERM);
+	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
+	    attr->map_type != BPF_MAP_TYPE_HASH)
+		return ERR_PTR(-EINVAL);
+
+	offmap = kzalloc(sizeof(*offmap), GFP_USER);
+	if (!offmap)
+		return ERR_PTR(-ENOMEM);
+
+	bpf_map_init_from_attr(&offmap->map, attr);
+
+	rtnl_lock();
+	down_write(&bpf_devs_lock);
+	offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
+	err = bpf_dev_offload_check(offmap->netdev);
+	if (err)
+		goto err_unlock;
+
+	ondev = bpf_offload_find_netdev(offmap->netdev);
+	if (!ondev) {
+		err = -EINVAL;
+		goto err_unlock;
+	}
+
+	err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
+	if (err)
+		goto err_unlock;
+
+	list_add_tail(&offmap->offloads, &ondev->maps);
+	up_write(&bpf_devs_lock);
+	rtnl_unlock();
+
+	return &offmap->map;
+
+err_unlock:
+	up_write(&bpf_devs_lock);
+	rtnl_unlock();
+	kfree(offmap);
+	return ERR_PTR(err);
+}
+
+static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
+{
+	WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
+	/* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
+	bpf_map_free_id(&offmap->map, true);
+	list_del_init(&offmap->offloads);
+	offmap->netdev = NULL;
+}
+
+void bpf_map_offload_map_free(struct bpf_map *map)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+
+	rtnl_lock();
+	down_write(&bpf_devs_lock);
+	if (offmap->netdev)
+		__bpf_map_offload_destroy(offmap);
+	up_write(&bpf_devs_lock);
+	rtnl_unlock();
+
+	kfree(offmap);
+}
+
+int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	if (offmap->netdev)
+		ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+int bpf_map_offload_update_elem(struct bpf_map *map,
+				void *key, void *value, u64 flags)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+	int ret = -ENODEV;
+
+	if (unlikely(flags > BPF_EXIST))
+		return -EINVAL;
+
+	down_read(&bpf_devs_lock);
+	if (offmap->netdev)
+		ret = offmap->dev_ops->map_update_elem(offmap, key, value,
+						       flags);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	if (offmap->netdev)
+		ret = offmap->dev_ops->map_delete_elem(offmap, key);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	if (offmap->netdev)
+		ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+struct ns_get_path_bpf_map_args {
+	struct bpf_offloaded_map *offmap;
+	struct bpf_map_info *info;
+};
+
+static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data)
+{
+	struct ns_get_path_bpf_map_args *args = private_data;
+	struct ns_common *ns;
+	struct net *net;
+
+	rtnl_lock();
+	down_read(&bpf_devs_lock);
+
+	if (args->offmap->netdev) {
+		args->info->ifindex = args->offmap->netdev->ifindex;
+		net = dev_net(args->offmap->netdev);
+		get_net(net);
+		ns = &net->ns;
+	} else {
+		args->info->ifindex = 0;
+		ns = NULL;
+	}
+
+	up_read(&bpf_devs_lock);
+	rtnl_unlock();
+
+	return ns;
+}
+
+int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
+{
+	struct ns_get_path_bpf_map_args args = {
+		.offmap	= map_to_offmap(map),
+		.info	= info,
+	};
+	struct inode *ns_inode;
+	struct path ns_path;
+	int res;
+
+	res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
+	if (res) {
+		if (!info->ifindex)
+			return -ENODEV;
+		return res;
+	}
+
+	ns_inode = ns_path.dentry->d_inode;
+	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
+	info->netns_ino = ns_inode->i_ino;
+	path_put(&ns_path);
+
+	return 0;
+}
+
+static bool __bpf_offload_dev_match(struct bpf_prog *prog,
+				    struct net_device *netdev)
+{
+	struct bpf_offload_netdev *ondev1, *ondev2;
+	struct bpf_prog_offload *offload;
+
+	if (!bpf_prog_is_dev_bound(prog->aux))
+		return false;
+
+	offload = prog->aux->offload;
+	if (!offload)
+		return false;
+	if (offload->netdev == netdev)
+		return true;
+
+	ondev1 = bpf_offload_find_netdev(offload->netdev);
+	ondev2 = bpf_offload_find_netdev(netdev);
+
+	return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
+}
+
+bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
+{
+	bool ret;
+
+	down_read(&bpf_devs_lock);
+	ret = __bpf_offload_dev_match(prog, netdev);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
+
+bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
+{
+	struct bpf_offloaded_map *offmap;
+	bool ret;
+
+	if (!bpf_map_is_dev_bound(map))
+		return bpf_map_offload_neutral(map);
+	offmap = map_to_offmap(map);
+
+	down_read(&bpf_devs_lock);
+	ret = __bpf_offload_dev_match(prog, offmap->netdev);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
+				    struct net_device *netdev)
+{
+	struct bpf_offload_netdev *ondev;
+	int err;
+
+	ondev = kzalloc(sizeof(*ondev), GFP_KERNEL);
+	if (!ondev)
+		return -ENOMEM;
+
+	ondev->netdev = netdev;
+	ondev->offdev = offdev;
+	INIT_LIST_HEAD(&ondev->progs);
+	INIT_LIST_HEAD(&ondev->maps);
+
+	down_write(&bpf_devs_lock);
+	err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params);
+	if (err) {
+		netdev_warn(netdev, "failed to register for BPF offload\n");
+		goto err_unlock_free;
+	}
+
+	list_add(&ondev->offdev_netdevs, &offdev->netdevs);
+	up_write(&bpf_devs_lock);
+	return 0;
+
+err_unlock_free:
+	up_write(&bpf_devs_lock);
+	kfree(ondev);
+	return err;
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);
+
+void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
+				       struct net_device *netdev)
+{
+	struct bpf_offload_netdev *ondev, *altdev;
+	struct bpf_offloaded_map *offmap, *mtmp;
+	struct bpf_prog_offload *offload, *ptmp;
+
+	ASSERT_RTNL();
+
+	down_write(&bpf_devs_lock);
+	ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
+	if (WARN_ON(!ondev))
+		goto unlock;
+
+	WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params));
+	list_del(&ondev->offdev_netdevs);
+
+	/* Try to move the objects to another netdev of the device */
+	altdev = list_first_entry_or_null(&offdev->netdevs,
+					  struct bpf_offload_netdev,
+					  offdev_netdevs);
+	if (altdev) {
+		list_for_each_entry(offload, &ondev->progs, offloads)
+			offload->netdev = altdev->netdev;
+		list_splice_init(&ondev->progs, &altdev->progs);
+
+		list_for_each_entry(offmap, &ondev->maps, offloads)
+			offmap->netdev = altdev->netdev;
+		list_splice_init(&ondev->maps, &altdev->maps);
+	} else {
+		list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads)
+			__bpf_prog_offload_destroy(offload->prog);
+		list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads)
+			__bpf_map_offload_destroy(offmap);
+	}
+
+	WARN_ON(!list_empty(&ondev->progs));
+	WARN_ON(!list_empty(&ondev->maps));
+	kfree(ondev);
+unlock:
+	up_write(&bpf_devs_lock);
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
+
+struct bpf_offload_dev *
+bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv)
+{
+	struct bpf_offload_dev *offdev;
+	int err;
+
+	down_write(&bpf_devs_lock);
+	if (!offdevs_inited) {
+		err = rhashtable_init(&offdevs, &offdevs_params);
+		if (err) {
+			up_write(&bpf_devs_lock);
+			return ERR_PTR(err);
+		}
+		offdevs_inited = true;
+	}
+	up_write(&bpf_devs_lock);
+
+	offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
+	if (!offdev)
+		return ERR_PTR(-ENOMEM);
+
+	offdev->ops = ops;
+	offdev->priv = priv;
+	INIT_LIST_HEAD(&offdev->netdevs);
+
+	return offdev;
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
+
+void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
+{
+	WARN_ON(!list_empty(&offdev->netdevs));
+	kfree(offdev);
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);
+
+void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev)
+{
+	return offdev->priv;
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_priv);
diff --git a/kernel/bpf/percpu_freelist.c b/kernel/bpf/percpu_freelist.c
new file mode 100644
index 000000000..bbab8bb4b
--- /dev/null
+++ b/kernel/bpf/percpu_freelist.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include "percpu_freelist.h"
+
+int pcpu_freelist_init(struct pcpu_freelist *s)
+{
+	int cpu;
+
+	s->freelist = alloc_percpu(struct pcpu_freelist_head);
+	if (!s->freelist)
+		return -ENOMEM;
+
+	for_each_possible_cpu(cpu) {
+		struct pcpu_freelist_head *head = per_cpu_ptr(s->freelist, cpu);
+
+		raw_spin_lock_init(&head->lock);
+		head->first = NULL;
+	}
+	raw_spin_lock_init(&s->extralist.lock);
+	s->extralist.first = NULL;
+	return 0;
+}
+
+void pcpu_freelist_destroy(struct pcpu_freelist *s)
+{
+	free_percpu(s->freelist);
+}
+
+static inline void pcpu_freelist_push_node(struct pcpu_freelist_head *head,
+					   struct pcpu_freelist_node *node)
+{
+	node->next = head->first;
+	head->first = node;
+}
+
+static inline void ___pcpu_freelist_push(struct pcpu_freelist_head *head,
+					 struct pcpu_freelist_node *node)
+{
+	raw_spin_lock(&head->lock);
+	pcpu_freelist_push_node(head, node);
+	raw_spin_unlock(&head->lock);
+}
+
+static inline bool pcpu_freelist_try_push_extra(struct pcpu_freelist *s,
+						struct pcpu_freelist_node *node)
+{
+	if (!raw_spin_trylock(&s->extralist.lock))
+		return false;
+
+	pcpu_freelist_push_node(&s->extralist, node);
+	raw_spin_unlock(&s->extralist.lock);
+	return true;
+}
+
+static inline void ___pcpu_freelist_push_nmi(struct pcpu_freelist *s,
+					     struct pcpu_freelist_node *node)
+{
+	int cpu, orig_cpu;
+
+	orig_cpu = cpu = raw_smp_processor_id();
+	while (1) {
+		struct pcpu_freelist_head *head;
+
+		head = per_cpu_ptr(s->freelist, cpu);
+		if (raw_spin_trylock(&head->lock)) {
+			pcpu_freelist_push_node(head, node);
+			raw_spin_unlock(&head->lock);
+			return;
+		}
+		cpu = cpumask_next(cpu, cpu_possible_mask);
+		if (cpu >= nr_cpu_ids)
+			cpu = 0;
+
+		/* cannot lock any per cpu lock, try extralist */
+		if (cpu == orig_cpu &&
+		    pcpu_freelist_try_push_extra(s, node))
+			return;
+	}
+}
+
+void __pcpu_freelist_push(struct pcpu_freelist *s,
+			struct pcpu_freelist_node *node)
+{
+	if (in_nmi())
+		___pcpu_freelist_push_nmi(s, node);
+	else
+		___pcpu_freelist_push(this_cpu_ptr(s->freelist), node);
+}
+
+void pcpu_freelist_push(struct pcpu_freelist *s,
+			struct pcpu_freelist_node *node)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__pcpu_freelist_push(s, node);
+	local_irq_restore(flags);
+}
+
+void pcpu_freelist_populate(struct pcpu_freelist *s, void *buf, u32 elem_size,
+			    u32 nr_elems)
+{
+	struct pcpu_freelist_head *head;
+	unsigned int cpu, cpu_idx, i, j, n, m;
+
+	n = nr_elems / num_possible_cpus();
+	m = nr_elems % num_possible_cpus();
+
+	cpu_idx = 0;
+	for_each_possible_cpu(cpu) {
+		head = per_cpu_ptr(s->freelist, cpu);
+		j = n + (cpu_idx < m ? 1 : 0);
+		for (i = 0; i < j; i++) {
+			/* No locking required as this is not visible yet. */
+			pcpu_freelist_push_node(head, buf);
+			buf += elem_size;
+		}
+		cpu_idx++;
+	}
+}
+
+static struct pcpu_freelist_node *___pcpu_freelist_pop(struct pcpu_freelist *s)
+{
+	struct pcpu_freelist_head *head;
+	struct pcpu_freelist_node *node;
+	int orig_cpu, cpu;
+
+	orig_cpu = cpu = raw_smp_processor_id();
+	while (1) {
+		head = per_cpu_ptr(s->freelist, cpu);
+		raw_spin_lock(&head->lock);
+		node = head->first;
+		if (node) {
+			head->first = node->next;
+			raw_spin_unlock(&head->lock);
+			return node;
+		}
+		raw_spin_unlock(&head->lock);
+		cpu = cpumask_next(cpu, cpu_possible_mask);
+		if (cpu >= nr_cpu_ids)
+			cpu = 0;
+		if (cpu == orig_cpu)
+			break;
+	}
+
+	/* per cpu lists are all empty, try extralist */
+	raw_spin_lock(&s->extralist.lock);
+	node = s->extralist.first;
+	if (node)
+		s->extralist.first = node->next;
+	raw_spin_unlock(&s->extralist.lock);
+	return node;
+}
+
+static struct pcpu_freelist_node *
+___pcpu_freelist_pop_nmi(struct pcpu_freelist *s)
+{
+	struct pcpu_freelist_head *head;
+	struct pcpu_freelist_node *node;
+	int orig_cpu, cpu;
+
+	orig_cpu = cpu = raw_smp_processor_id();
+	while (1) {
+		head = per_cpu_ptr(s->freelist, cpu);
+		if (raw_spin_trylock(&head->lock)) {
+			node = head->first;
+			if (node) {
+				head->first = node->next;
+				raw_spin_unlock(&head->lock);
+				return node;
+			}
+			raw_spin_unlock(&head->lock);
+		}
+		cpu = cpumask_next(cpu, cpu_possible_mask);
+		if (cpu >= nr_cpu_ids)
+			cpu = 0;
+		if (cpu == orig_cpu)
+			break;
+	}
+
+	/* cannot pop from per cpu lists, try extralist */
+	if (!raw_spin_trylock(&s->extralist.lock))
+		return NULL;
+	node = s->extralist.first;
+	if (node)
+		s->extralist.first = node->next;
+	raw_spin_unlock(&s->extralist.lock);
+	return node;
+}
+
+struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *s)
+{
+	if (in_nmi())
+		return ___pcpu_freelist_pop_nmi(s);
+	return ___pcpu_freelist_pop(s);
+}
+
+struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *s)
+{
+	struct pcpu_freelist_node *ret;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	ret = __pcpu_freelist_pop(s);
+	local_irq_restore(flags);
+	return ret;
+}
diff --git a/kernel/bpf/percpu_freelist.h b/kernel/bpf/percpu_freelist.h
new file mode 100644
index 000000000..3c76553cf
--- /dev/null
+++ b/kernel/bpf/percpu_freelist.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2016 Facebook
+ */
+#ifndef __PERCPU_FREELIST_H__
+#define __PERCPU_FREELIST_H__
+#include <linux/spinlock.h>
+#include <linux/percpu.h>
+
+struct pcpu_freelist_head {
+	struct pcpu_freelist_node *first;
+	raw_spinlock_t lock;
+};
+
+struct pcpu_freelist {
+	struct pcpu_freelist_head __percpu *freelist;
+	struct pcpu_freelist_head extralist;
+};
+
+struct pcpu_freelist_node {
+	struct pcpu_freelist_node *next;
+};
+
+/* pcpu_freelist_* do spin_lock_irqsave. */
+void pcpu_freelist_push(struct pcpu_freelist *, struct pcpu_freelist_node *);
+struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *);
+/* __pcpu_freelist_* do spin_lock only. caller must disable irqs. */
+void __pcpu_freelist_push(struct pcpu_freelist *, struct pcpu_freelist_node *);
+struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *);
+void pcpu_freelist_populate(struct pcpu_freelist *s, void *buf, u32 elem_size,
+			    u32 nr_elems);
+int pcpu_freelist_init(struct pcpu_freelist *);
+void pcpu_freelist_destroy(struct pcpu_freelist *s);
+#endif
diff --git a/kernel/bpf/preload/.gitignore b/kernel/bpf/preload/.gitignore
new file mode 100644
index 000000000..856a4c5ad
--- /dev/null
+++ b/kernel/bpf/preload/.gitignore
@@ -0,0 +1,4 @@
+/FEATURE-DUMP.libbpf
+/bpf_helper_defs.h
+/feature
+/bpf_preload_umd
diff --git a/kernel/bpf/preload/Kconfig b/kernel/bpf/preload/Kconfig
new file mode 100644
index 000000000..26bced262
--- /dev/null
+++ b/kernel/bpf/preload/Kconfig
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config USERMODE_DRIVER
+	bool
+	default n
+
+menuconfig BPF_PRELOAD
+	bool "Preload BPF file system with kernel specific program and map iterators"
+	depends on BPF
+	depends on BPF_SYSCALL
+	# The dependency on !COMPILE_TEST prevents it from being enabled
+	# in allmodconfig or allyesconfig configurations
+	depends on !COMPILE_TEST
+	select USERMODE_DRIVER
+	help
+	  This builds kernel module with several embedded BPF programs that are
+	  pinned into BPF FS mount point as human readable files that are
+	  useful in debugging and introspection of BPF programs and maps.
+
+if BPF_PRELOAD
+config BPF_PRELOAD_UMD
+	tristate "bpf_preload kernel module with user mode driver"
+	depends on CC_CAN_LINK
+	depends on m || CC_CAN_LINK_STATIC
+	default m
+	help
+	  This builds bpf_preload kernel module with embedded user mode driver.
+endif
diff --git a/kernel/bpf/preload/Makefile b/kernel/bpf/preload/Makefile
new file mode 100644
index 000000000..1951332dd
--- /dev/null
+++ b/kernel/bpf/preload/Makefile
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+
+LIBBPF_SRCS = $(srctree)/tools/lib/bpf/
+LIBBPF_A = $(obj)/libbpf.a
+LIBBPF_OUT = $(abspath $(obj))
+
+# Although not in use by libbpf's Makefile, set $(O) so that the "dummy" test
+# in tools/scripts/Makefile.include always succeeds when building the kernel
+# with $(O) pointing to a relative path, as in "make O=build bindeb-pkg".
+$(LIBBPF_A):
+	$(Q)$(MAKE) -C $(LIBBPF_SRCS) O=$(LIBBPF_OUT)/ OUTPUT=$(LIBBPF_OUT)/ $(LIBBPF_OUT)/libbpf.a
+
+userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi \
+	-I $(srctree)/tools/lib/ -Wno-unused-result
+
+userprogs := bpf_preload_umd
+
+clean-files := $(userprogs) bpf_helper_defs.h FEATURE-DUMP.libbpf staticobjs/ feature/
+
+bpf_preload_umd-objs := iterators/iterators.o
+bpf_preload_umd-userldlibs := $(LIBBPF_A) -lelf -lz
+
+$(obj)/bpf_preload_umd: $(LIBBPF_A)
+
+$(obj)/bpf_preload_umd_blob.o: $(obj)/bpf_preload_umd
+
+obj-$(CONFIG_BPF_PRELOAD_UMD) += bpf_preload.o
+bpf_preload-objs += bpf_preload_kern.o bpf_preload_umd_blob.o
diff --git a/kernel/bpf/preload/bpf_preload.h b/kernel/bpf/preload/bpf_preload.h
new file mode 100644
index 000000000..2f9932276
--- /dev/null
+++ b/kernel/bpf/preload/bpf_preload.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BPF_PRELOAD_H
+#define _BPF_PRELOAD_H
+
+#include <linux/usermode_driver.h>
+#include "iterators/bpf_preload_common.h"
+
+struct bpf_preload_ops {
+        struct umd_info info;
+	int (*preload)(struct bpf_preload_info *);
+	int (*finish)(void);
+	struct module *owner;
+};
+extern struct bpf_preload_ops *bpf_preload_ops;
+#define BPF_PRELOAD_LINKS 2
+#endif
diff --git a/kernel/bpf/preload/bpf_preload_kern.c b/kernel/bpf/preload/bpf_preload_kern.c
new file mode 100644
index 000000000..53736e52c
--- /dev/null
+++ b/kernel/bpf/preload/bpf_preload_kern.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pid.h>
+#include <linux/fs.h>
+#include <linux/sched/signal.h>
+#include "bpf_preload.h"
+
+extern char bpf_preload_umd_start;
+extern char bpf_preload_umd_end;
+
+static int preload(struct bpf_preload_info *obj);
+static int finish(void);
+
+static struct bpf_preload_ops umd_ops = {
+	.info.driver_name = "bpf_preload",
+	.preload = preload,
+	.finish = finish,
+	.owner = THIS_MODULE,
+};
+
+static int preload(struct bpf_preload_info *obj)
+{
+	int magic = BPF_PRELOAD_START;
+	loff_t pos = 0;
+	int i, err;
+	ssize_t n;
+
+	err = fork_usermode_driver(&umd_ops.info);
+	if (err)
+		return err;
+
+	/* send the start magic to let UMD proceed with loading BPF progs */
+	n = kernel_write(umd_ops.info.pipe_to_umh,
+			 &magic, sizeof(magic), &pos);
+	if (n != sizeof(magic))
+		return -EPIPE;
+
+	/* receive bpf_link IDs and names from UMD */
+	pos = 0;
+	for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
+		n = kernel_read(umd_ops.info.pipe_from_umh,
+				&obj[i], sizeof(*obj), &pos);
+		if (n != sizeof(*obj))
+			return -EPIPE;
+	}
+	return 0;
+}
+
+static int finish(void)
+{
+	int magic = BPF_PRELOAD_END;
+	struct pid *tgid;
+	loff_t pos = 0;
+	ssize_t n;
+
+	/* send the last magic to UMD. It will do a normal exit. */
+	n = kernel_write(umd_ops.info.pipe_to_umh,
+			 &magic, sizeof(magic), &pos);
+	if (n != sizeof(magic))
+		return -EPIPE;
+
+	tgid = umd_ops.info.tgid;
+	if (tgid) {
+		wait_event(tgid->wait_pidfd, thread_group_exited(tgid));
+		umd_cleanup_helper(&umd_ops.info);
+	}
+	return 0;
+}
+
+static int __init load_umd(void)
+{
+	int err;
+
+	err = umd_load_blob(&umd_ops.info, &bpf_preload_umd_start,
+			    &bpf_preload_umd_end - &bpf_preload_umd_start);
+	if (err)
+		return err;
+	bpf_preload_ops = &umd_ops;
+	return err;
+}
+
+static void __exit fini_umd(void)
+{
+	struct pid *tgid;
+
+	bpf_preload_ops = NULL;
+
+	/* kill UMD in case it's still there due to earlier error */
+	tgid = umd_ops.info.tgid;
+	if (tgid) {
+		kill_pid(tgid, SIGKILL, 1);
+
+		wait_event(tgid->wait_pidfd, thread_group_exited(tgid));
+		umd_cleanup_helper(&umd_ops.info);
+	}
+	umd_unload_blob(&umd_ops.info);
+}
+late_initcall(load_umd);
+module_exit(fini_umd);
+MODULE_LICENSE("GPL");
diff --git a/kernel/bpf/preload/bpf_preload_umd_blob.S b/kernel/bpf/preload/bpf_preload_umd_blob.S
new file mode 100644
index 000000000..f1f40223b
--- /dev/null
+++ b/kernel/bpf/preload/bpf_preload_umd_blob.S
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+	.section .init.rodata, "a"
+	.global bpf_preload_umd_start
+bpf_preload_umd_start:
+	.incbin "kernel/bpf/preload/bpf_preload_umd"
+	.global bpf_preload_umd_end
+bpf_preload_umd_end:
diff --git a/kernel/bpf/preload/iterators/.gitignore b/kernel/bpf/preload/iterators/.gitignore
new file mode 100644
index 000000000..ffdb70230
--- /dev/null
+++ b/kernel/bpf/preload/iterators/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/.output
diff --git a/kernel/bpf/preload/iterators/Makefile b/kernel/bpf/preload/iterators/Makefile
new file mode 100644
index 000000000..28fa8c144
--- /dev/null
+++ b/kernel/bpf/preload/iterators/Makefile
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0
+OUTPUT := .output
+CLANG ?= clang
+LLC ?= llc
+LLVM_STRIP ?= llvm-strip
+DEFAULT_BPFTOOL := $(OUTPUT)/sbin/bpftool
+BPFTOOL ?= $(DEFAULT_BPFTOOL)
+LIBBPF_SRC := $(abspath ../../../../tools/lib/bpf)
+BPFOBJ := $(OUTPUT)/libbpf.a
+BPF_INCLUDE := $(OUTPUT)
+INCLUDES := -I$(OUTPUT) -I$(BPF_INCLUDE) -I$(abspath ../../../../tools/lib)        \
+       -I$(abspath ../../../../tools/include/uapi)
+CFLAGS := -g -Wall
+
+abs_out := $(abspath $(OUTPUT))
+ifeq ($(V),1)
+Q =
+msg =
+else
+Q = @
+msg = @printf '  %-8s %s%s\n' "$(1)" "$(notdir $(2))" "$(if $(3), $(3))";
+MAKEFLAGS += --no-print-directory
+submake_extras := feature_display=0
+endif
+
+.DELETE_ON_ERROR:
+
+.PHONY: all clean
+
+all: iterators.skel.h
+
+clean:
+	$(call msg,CLEAN)
+	$(Q)rm -rf $(OUTPUT) iterators
+
+iterators.skel.h: $(OUTPUT)/iterators.bpf.o | $(BPFTOOL)
+	$(call msg,GEN-SKEL,$@)
+	$(Q)$(BPFTOOL) gen skeleton $< > $@
+
+
+$(OUTPUT)/iterators.bpf.o: iterators.bpf.c $(BPFOBJ) | $(OUTPUT)
+	$(call msg,BPF,$@)
+	$(Q)$(CLANG) -g -O2 -target bpf $(INCLUDES)			      \
+		 -c $(filter %.c,$^) -o $@ &&				      \
+	$(LLVM_STRIP) -g $@
+
+$(OUTPUT):
+	$(call msg,MKDIR,$@)
+	$(Q)mkdir -p $(OUTPUT)
+
+$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(OUTPUT)
+	$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC)			       \
+		    OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
+
+$(DEFAULT_BPFTOOL):
+	$(Q)$(MAKE) $(submake_extras) -C ../../../../tools/bpf/bpftool			      \
+		    prefix= OUTPUT=$(abs_out)/ DESTDIR=$(abs_out) install
diff --git a/kernel/bpf/preload/iterators/README b/kernel/bpf/preload/iterators/README
new file mode 100644
index 000000000..7fd6d39a9
--- /dev/null
+++ b/kernel/bpf/preload/iterators/README
@@ -0,0 +1,4 @@
+WARNING:
+If you change "iterators.bpf.c" do "make -j" in this directory to rebuild "iterators.skel.h".
+Make sure to have clang 10 installed.
+See Documentation/bpf/bpf_devel_QA.rst
diff --git a/kernel/bpf/preload/iterators/bpf_preload_common.h b/kernel/bpf/preload/iterators/bpf_preload_common.h
new file mode 100644
index 000000000..8464d1a48
--- /dev/null
+++ b/kernel/bpf/preload/iterators/bpf_preload_common.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BPF_PRELOAD_COMMON_H
+#define _BPF_PRELOAD_COMMON_H
+
+#define BPF_PRELOAD_START 0x5555
+#define BPF_PRELOAD_END 0xAAAA
+
+struct bpf_preload_info {
+	char link_name[16];
+	int link_id;
+};
+
+#endif
diff --git a/kernel/bpf/preload/iterators/iterators.bpf.c b/kernel/bpf/preload/iterators/iterators.bpf.c
new file mode 100644
index 000000000..52aa7b38e
--- /dev/null
+++ b/kernel/bpf/preload/iterators/iterators.bpf.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)
+struct seq_file;
+struct bpf_iter_meta {
+	struct seq_file *seq;
+	__u64 session_id;
+	__u64 seq_num;
+};
+
+struct bpf_map {
+	__u32 id;
+	char name[16];
+	__u32 max_entries;
+};
+
+struct bpf_iter__bpf_map {
+	struct bpf_iter_meta *meta;
+	struct bpf_map *map;
+};
+
+struct btf_type {
+	__u32 name_off;
+};
+
+struct btf_header {
+	__u32   str_len;
+};
+
+struct btf {
+	const char *strings;
+	struct btf_type **types;
+	struct btf_header hdr;
+};
+
+struct bpf_prog_aux {
+	__u32 id;
+	char name[16];
+	const char *attach_func_name;
+	struct bpf_prog *dst_prog;
+	struct bpf_func_info *func_info;
+	struct btf *btf;
+};
+
+struct bpf_prog {
+	struct bpf_prog_aux *aux;
+};
+
+struct bpf_iter__bpf_prog {
+	struct bpf_iter_meta *meta;
+	struct bpf_prog *prog;
+};
+#pragma clang attribute pop
+
+static const char *get_name(struct btf *btf, long btf_id, const char *fallback)
+{
+	struct btf_type **types, *t;
+	unsigned int name_off;
+	const char *str;
+
+	if (!btf)
+		return fallback;
+	str = btf->strings;
+	types = btf->types;
+	bpf_probe_read_kernel(&t, sizeof(t), types + btf_id);
+	name_off = BPF_CORE_READ(t, name_off);
+	if (name_off >= btf->hdr.str_len)
+		return fallback;
+	return str + name_off;
+}
+
+SEC("iter/bpf_map")
+int dump_bpf_map(struct bpf_iter__bpf_map *ctx)
+{
+	struct seq_file *seq = ctx->meta->seq;
+	__u64 seq_num = ctx->meta->seq_num;
+	struct bpf_map *map = ctx->map;
+
+	if (!map)
+		return 0;
+
+	if (seq_num == 0)
+		BPF_SEQ_PRINTF(seq, "  id name             max_entries\n");
+
+	BPF_SEQ_PRINTF(seq, "%4u %-16s%6d\n", map->id, map->name, map->max_entries);
+	return 0;
+}
+
+SEC("iter/bpf_prog")
+int dump_bpf_prog(struct bpf_iter__bpf_prog *ctx)
+{
+	struct seq_file *seq = ctx->meta->seq;
+	__u64 seq_num = ctx->meta->seq_num;
+	struct bpf_prog *prog = ctx->prog;
+	struct bpf_prog_aux *aux;
+
+	if (!prog)
+		return 0;
+
+	aux = prog->aux;
+	if (seq_num == 0)
+		BPF_SEQ_PRINTF(seq, "  id name             attached\n");
+
+	BPF_SEQ_PRINTF(seq, "%4u %-16s %s %s\n", aux->id,
+		       get_name(aux->btf, aux->func_info[0].type_id, aux->name),
+		       aux->attach_func_name, aux->dst_prog->aux->name);
+	return 0;
+}
+char LICENSE[] SEC("license") = "GPL";
diff --git a/kernel/bpf/preload/iterators/iterators.c b/kernel/bpf/preload/iterators/iterators.c
new file mode 100644
index 000000000..b7ff87939
--- /dev/null
+++ b/kernel/bpf/preload/iterators/iterators.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include <argp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/resource.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include <sys/mount.h>
+#include "iterators.skel.h"
+#include "bpf_preload_common.h"
+
+int to_kernel = -1;
+int from_kernel = 0;
+
+static int send_link_to_kernel(struct bpf_link *link, const char *link_name)
+{
+	struct bpf_preload_info obj = {};
+	struct bpf_link_info info = {};
+	__u32 info_len = sizeof(info);
+	int err;
+
+	err = bpf_obj_get_info_by_fd(bpf_link__fd(link), &info, &info_len);
+	if (err)
+		return err;
+	obj.link_id = info.id;
+	if (strlen(link_name) >= sizeof(obj.link_name))
+		return -E2BIG;
+	strcpy(obj.link_name, link_name);
+	if (write(to_kernel, &obj, sizeof(obj)) != sizeof(obj))
+		return -EPIPE;
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit rlim = { RLIM_INFINITY, RLIM_INFINITY };
+	struct iterators_bpf *skel;
+	int err, magic;
+	int debug_fd;
+
+	debug_fd = open("/dev/console", O_WRONLY | O_NOCTTY | O_CLOEXEC);
+	if (debug_fd < 0)
+		return 1;
+	to_kernel = dup(1);
+	close(1);
+	dup(debug_fd);
+	/* now stdin and stderr point to /dev/console */
+
+	read(from_kernel, &magic, sizeof(magic));
+	if (magic != BPF_PRELOAD_START) {
+		printf("bad start magic %d\n", magic);
+		return 1;
+	}
+	setrlimit(RLIMIT_MEMLOCK, &rlim);
+	/* libbpf opens BPF object and loads it into the kernel */
+	skel = iterators_bpf__open_and_load();
+	if (!skel) {
+		/* iterators.skel.h is little endian.
+		 * libbpf doesn't support automatic little->big conversion
+		 * of BPF bytecode yet.
+		 * The program load will fail in such case.
+		 */
+		printf("Failed load could be due to wrong endianness\n");
+		return 1;
+	}
+	err = iterators_bpf__attach(skel);
+	if (err)
+		goto cleanup;
+
+	/* send two bpf_link IDs with names to the kernel */
+	err = send_link_to_kernel(skel->links.dump_bpf_map, "maps.debug");
+	if (err)
+		goto cleanup;
+	err = send_link_to_kernel(skel->links.dump_bpf_prog, "progs.debug");
+	if (err)
+		goto cleanup;
+
+	/* The kernel will proceed with pinnging the links in bpffs.
+	 * UMD will wait on read from pipe.
+	 */
+	read(from_kernel, &magic, sizeof(magic));
+	if (magic != BPF_PRELOAD_END) {
+		printf("bad final magic %d\n", magic);
+		err = -EINVAL;
+	}
+cleanup:
+	iterators_bpf__destroy(skel);
+
+	return err != 0;
+}
diff --git a/kernel/bpf/preload/iterators/iterators.skel.h b/kernel/bpf/preload/iterators/iterators.skel.h
new file mode 100644
index 000000000..cf9a6a94b
--- /dev/null
+++ b/kernel/bpf/preload/iterators/iterators.skel.h
@@ -0,0 +1,412 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/* THIS FILE IS AUTOGENERATED! */
+#ifndef __ITERATORS_BPF_SKEL_H__
+#define __ITERATORS_BPF_SKEL_H__
+
+#include <stdlib.h>
+#include <bpf/libbpf.h>
+
+struct iterators_bpf {
+	struct bpf_object_skeleton *skeleton;
+	struct bpf_object *obj;
+	struct {
+		struct bpf_map *rodata;
+	} maps;
+	struct {
+		struct bpf_program *dump_bpf_map;
+		struct bpf_program *dump_bpf_prog;
+	} progs;
+	struct {
+		struct bpf_link *dump_bpf_map;
+		struct bpf_link *dump_bpf_prog;
+	} links;
+	struct iterators_bpf__rodata {
+		char dump_bpf_map____fmt[35];
+		char dump_bpf_map____fmt_1[14];
+		char dump_bpf_prog____fmt[32];
+		char dump_bpf_prog____fmt_2[17];
+	} *rodata;
+};
+
+static void
+iterators_bpf__destroy(struct iterators_bpf *obj)
+{
+	if (!obj)
+		return;
+	if (obj->skeleton)
+		bpf_object__destroy_skeleton(obj->skeleton);
+	free(obj);
+}
+
+static inline int
+iterators_bpf__create_skeleton(struct iterators_bpf *obj);
+
+static inline struct iterators_bpf *
+iterators_bpf__open_opts(const struct bpf_object_open_opts *opts)
+{
+	struct iterators_bpf *obj;
+
+	obj = (struct iterators_bpf *)calloc(1, sizeof(*obj));
+	if (!obj)
+		return NULL;
+	if (iterators_bpf__create_skeleton(obj))
+		goto err;
+	if (bpf_object__open_skeleton(obj->skeleton, opts))
+		goto err;
+
+	return obj;
+err:
+	iterators_bpf__destroy(obj);
+	return NULL;
+}
+
+static inline struct iterators_bpf *
+iterators_bpf__open(void)
+{
+	return iterators_bpf__open_opts(NULL);
+}
+
+static inline int
+iterators_bpf__load(struct iterators_bpf *obj)
+{
+	return bpf_object__load_skeleton(obj->skeleton);
+}
+
+static inline struct iterators_bpf *
+iterators_bpf__open_and_load(void)
+{
+	struct iterators_bpf *obj;
+
+	obj = iterators_bpf__open();
+	if (!obj)
+		return NULL;
+	if (iterators_bpf__load(obj)) {
+		iterators_bpf__destroy(obj);
+		return NULL;
+	}
+	return obj;
+}
+
+static inline int
+iterators_bpf__attach(struct iterators_bpf *obj)
+{
+	return bpf_object__attach_skeleton(obj->skeleton);
+}
+
+static inline void
+iterators_bpf__detach(struct iterators_bpf *obj)
+{
+	return bpf_object__detach_skeleton(obj->skeleton);
+}
+
+static inline int
+iterators_bpf__create_skeleton(struct iterators_bpf *obj)
+{
+	struct bpf_object_skeleton *s;
+
+	s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));
+	if (!s)
+		return -1;
+	obj->skeleton = s;
+
+	s->sz = sizeof(*s);
+	s->name = "iterators_bpf";
+	s->obj = &obj->obj;
+
+	/* maps */
+	s->map_cnt = 1;
+	s->map_skel_sz = sizeof(*s->maps);
+	s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);
+	if (!s->maps)
+		goto err;
+
+	s->maps[0].name = "iterator.rodata";
+	s->maps[0].map = &obj->maps.rodata;
+	s->maps[0].mmaped = (void **)&obj->rodata;
+
+	/* programs */
+	s->prog_cnt = 2;
+	s->prog_skel_sz = sizeof(*s->progs);
+	s->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);
+	if (!s->progs)
+		goto err;
+
+	s->progs[0].name = "dump_bpf_map";
+	s->progs[0].prog = &obj->progs.dump_bpf_map;
+	s->progs[0].link = &obj->links.dump_bpf_map;
+
+	s->progs[1].name = "dump_bpf_prog";
+	s->progs[1].prog = &obj->progs.dump_bpf_prog;
+	s->progs[1].link = &obj->links.dump_bpf_prog;
+
+	s->data_sz = 7176;
+	s->data = (void *)"\
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+\x0c\0\0\0\x1c\x03\0\0\0\0\0\0\0\0\0\0\x0c\0\0\0\x2c\x03\0\0\0\0\0\0\0\0\0\0\
+\x0c\0\0\0\x3c\x03\0\0\0\0\0\0\0\0\0\0\x0c\0\0\0\x4c\x03\0\0\0\0\0\0\0\0\0\0\
+\x0c\0\0\0\x5c\x03\0\0\0\0\0\0\0\0\0\0\x0c\0\0\0\x6c\x03\0\0\0\0\0\0\0\0\0\0\
+\x0c\0\0\0\x7c\x03\0\0\0\0\0\0\0\0\0\0\x0c\0\0\0\x8c\x03\0\0\0\0\0\0\0\0\0\0\
+\x0c\0\0\0\x9c\x03\0\0\0\0\0\0\0\0\0\0\x0c\0\0\0\xac\x03\0\0\0\0\0\0\0\0\0\0\
+\x0c\0\0\0\xbc\x03\0\0\0\0\0\0\0\0\0\0\x0c\0\0\0\xcc\x03\0\0\0\0\0\0\0\0\0\0\
+\x0c\0\0\0\xdc\x03\0\0\0\0\0\0\0\0\0\0\x0c\0\0\0\xec\x03\0\0\0\0\0\0\0\0\0\0\
+\x0c\0\0\0\xfc\x03\0\0\0\0\0\0\0\0\0\0\x0c\0\0\0\x0c\x04\0\0\0\0\0\0\0\0\0\0\
+\x0c\0\0\0\x1c\x04\0\0\0\0\0\0\0\0\0\0\x0c\0\0\0\x4d\x4e\x40\x41\x42\x43\x4c\0\
+\x2e\x74\x65\x78\x74\0\x2e\x72\x65\x6c\x2e\x42\x54\x46\x2e\x65\x78\x74\0\x64\
+\x75\x6d\x70\x5f\x62\x70\x66\x5f\x6d\x61\x70\x2e\x5f\x5f\x5f\x66\x6d\x74\0\x64\
+\x75\x6d\x70\x5f\x62\x70\x66\x5f\x70\x72\x6f\x67\x2e\x5f\x5f\x5f\x66\x6d\x74\0\
+\x64\x75\x6d\x70\x5f\x62\x70\x66\x5f\x6d\x61\x70\0\x2e\x72\x65\x6c\x69\x74\x65\
+\x72\x2f\x62\x70\x66\x5f\x6d\x61\x70\0\x64\x75\x6d\x70\x5f\x62\x70\x66\x5f\x70\
+\x72\x6f\x67\0\x2e\x72\x65\x6c\x69\x74\x65\x72\x2f\x62\x70\x66\x5f\x70\x72\x6f\
+\x67\0\x2e\x6c\x6c\x76\x6d\x5f\x61\x64\x64\x72\x73\x69\x67\0\x6c\x69\x63\x65\
+\x6e\x73\x65\0\x69\x74\x65\x72\x61\x74\x6f\x72\x73\x2e\x62\x70\x66\x2e\x63\0\
+\x2e\x73\x74\x72\x74\x61\x62\0\x2e\x73\x79\x6d\x74\x61\x62\0\x2e\x72\x6f\x64\
+\x61\x74\x61\0\x2e\x72\x65\x6c\x2e\x42\x54\x46\0\x4c\x49\x43\x45\x4e\x53\x45\0\
+\x4c\x42\x42\x31\x5f\x37\0\x4c\x42\x42\x31\x5f\x36\0\x4c\x42\x42\x30\x5f\x34\0\
+\x4c\x42\x42\x31\x5f\x33\0\x4c\x42\x42\x30\x5f\x33\0\x64\x75\x6d\x70\x5f\x62\
+\x70\x66\x5f\x70\x72\x6f\x67\x2e\x5f\x5f\x5f\x66\x6d\x74\x2e\x32\0\x64\x75\x6d\
+\x70\x5f\x62\x70\x66\x5f\x6d\x61\x70\x2e\x5f\x5f\x5f\x66\x6d\x74\x2e\x31\0\0\0\
+\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
+\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x01\0\0\0\x01\0\0\
+\0\x06\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x40\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
+\0\0\0\0\x04\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x4e\0\0\0\x01\0\0\0\x06\0\0\0\0\0\0\
+\0\0\0\0\0\0\0\0\0\x40\0\0\0\0\0\0\0\0\x01\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x08\0\0\
+\0\0\0\0\0\0\0\0\0\0\0\0\0\x6d\0\0\0\x01\0\0\0\x06\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
+\0\x40\x01\0\0\0\0\0\0\x08\x02\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x08\0\0\0\0\0\0\0\0\
+\0\0\0\0\0\0\0\xb1\0\0\0\x01\0\0\0\x02\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x48\x03\0\
+\0\0\0\0\0\x62\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x01\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
+\x89\0\0\0\x01\0\0\0\x03\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\xaa\x03\0\0\0\0\0\0\x04\
+\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x01\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\xbd\0\0\0\x01\
+\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\xae\x03\0\0\0\0\0\0\x3d\x09\0\0\0\0\0\0\
+\0\0\0\0\0\0\0\0\x01\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x0b\0\0\0\x01\0\0\0\0\0\0\0\
+\0\0\0\0\0\0\0\0\0\0\0\0\xeb\x0c\0\0\0\0\0\0\x2c\x04\0\0\0\0\0\0\0\0\0\0\0\0\0\
+\0\x01\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\xa9\0\0\0\x02\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
+\0\0\0\0\0\x18\x11\0\0\0\0\0\0\x98\x01\0\0\0\0\0\0\x0e\0\0\0\x0e\0\0\0\x08\0\0\
+\0\0\0\0\0\x18\0\0\0\0\0\0\0\x4a\0\0\0\x09\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
+\0\xb0\x12\0\0\0\0\0\0\x20\0\0\0\0\0\0\0\x08\0\0\0\x02\0\0\0\x08\0\0\0\0\0\0\0\
+\x10\0\0\0\0\0\0\0\x69\0\0\0\x09\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\xd0\x12\
+\0\0\0\0\0\0\x20\0\0\0\0\0\0\0\x08\0\0\0\x03\0\0\0\x08\0\0\0\0\0\0\0\x10\0\0\0\
+\0\0\0\0\xb9\0\0\0\x09\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\xf0\x12\0\0\0\0\0\
+\0\x50\0\0\0\0\0\0\0\x08\0\0\0\x06\0\0\0\x08\0\0\0\0\0\0\0\x10\0\0\0\0\0\0\0\
+\x07\0\0\0\x09\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x40\x13\0\0\0\0\0\0\xe0\
+\x03\0\0\0\0\0\0\x08\0\0\0\x07\0\0\0\x08\0\0\0\0\0\0\0\x10\0\0\0\0\0\0\0\x7b\0\
+\0\0\x03\x4c\xff\x6f\0\0\0\x80\0\0\0\0\0\0\0\0\0\0\0\0\x20\x17\0\0\0\0\0\0\x07\
+\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x01\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\xa1\0\0\0\x03\
+\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x27\x17\0\0\0\0\0\0\x1a\x01\0\0\0\0\0\0\
+\0\0\0\0\0\0\0\0\x01\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
+
+	return 0;
+err:
+	bpf_object__destroy_skeleton(s);
+	return -1;
+}
+
+#endif /* __ITERATORS_BPF_SKEL_H__ */
diff --git a/kernel/bpf/prog_iter.c b/kernel/bpf/prog_iter.c
new file mode 100644
index 000000000..53a73c841
--- /dev/null
+++ b/kernel/bpf/prog_iter.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 Facebook */
+#include <linux/bpf.h>
+#include <linux/fs.h>
+#include <linux/filter.h>
+#include <linux/kernel.h>
+#include <linux/btf_ids.h>
+
+struct bpf_iter_seq_prog_info {
+	u32 prog_id;
+};
+
+static void *bpf_prog_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_prog_info *info = seq->private;
+	struct bpf_prog *prog;
+
+	prog = bpf_prog_get_curr_or_next(&info->prog_id);
+	if (!prog)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	return prog;
+}
+
+static void *bpf_prog_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_prog_info *info = seq->private;
+
+	++*pos;
+	++info->prog_id;
+	bpf_prog_put((struct bpf_prog *)v);
+	return bpf_prog_get_curr_or_next(&info->prog_id);
+}
+
+struct bpf_iter__bpf_prog {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct bpf_prog *, prog);
+};
+
+DEFINE_BPF_ITER_FUNC(bpf_prog, struct bpf_iter_meta *meta, struct bpf_prog *prog)
+
+static int __bpf_prog_seq_show(struct seq_file *seq, void *v, bool in_stop)
+{
+	struct bpf_iter__bpf_prog ctx;
+	struct bpf_iter_meta meta;
+	struct bpf_prog *prog;
+	int ret = 0;
+
+	ctx.meta = &meta;
+	ctx.prog = v;
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, in_stop);
+	if (prog)
+		ret = bpf_iter_run_prog(prog, &ctx);
+
+	return ret;
+}
+
+static int bpf_prog_seq_show(struct seq_file *seq, void *v)
+{
+	return __bpf_prog_seq_show(seq, v, false);
+}
+
+static void bpf_prog_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__bpf_prog_seq_show(seq, v, true);
+	else
+		bpf_prog_put((struct bpf_prog *)v);
+}
+
+static const struct seq_operations bpf_prog_seq_ops = {
+	.start	= bpf_prog_seq_start,
+	.next	= bpf_prog_seq_next,
+	.stop	= bpf_prog_seq_stop,
+	.show	= bpf_prog_seq_show,
+};
+
+BTF_ID_LIST(btf_bpf_prog_id)
+BTF_ID(struct, bpf_prog)
+
+static const struct bpf_iter_seq_info bpf_prog_seq_info = {
+	.seq_ops		= &bpf_prog_seq_ops,
+	.init_seq_private	= NULL,
+	.fini_seq_private	= NULL,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_prog_info),
+};
+
+static struct bpf_iter_reg bpf_prog_reg_info = {
+	.target			= "bpf_prog",
+	.ctx_arg_info_size	= 1,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__bpf_prog, prog),
+		  PTR_TO_BTF_ID_OR_NULL },
+	},
+	.seq_info		= &bpf_prog_seq_info,
+};
+
+static int __init bpf_prog_iter_init(void)
+{
+	bpf_prog_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_prog_id;
+	return bpf_iter_reg_target(&bpf_prog_reg_info);
+}
+
+late_initcall(bpf_prog_iter_init);
diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c
new file mode 100644
index 000000000..a047a2053
--- /dev/null
+++ b/kernel/bpf/queue_stack_maps.c
@@ -0,0 +1,305 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * queue_stack_maps.c: BPF queue and stack maps
+ *
+ * Copyright (c) 2018 Politecnico di Torino
+ */
+#include <linux/bpf.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/capability.h>
+#include "percpu_freelist.h"
+
+#define QUEUE_STACK_CREATE_FLAG_MASK \
+	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
+
+struct bpf_queue_stack {
+	struct bpf_map map;
+	raw_spinlock_t lock;
+	u32 head, tail;
+	u32 size; /* max_entries + 1 */
+
+	char elements[] __aligned(8);
+};
+
+static struct bpf_queue_stack *bpf_queue_stack(struct bpf_map *map)
+{
+	return container_of(map, struct bpf_queue_stack, map);
+}
+
+static bool queue_stack_map_is_empty(struct bpf_queue_stack *qs)
+{
+	return qs->head == qs->tail;
+}
+
+static bool queue_stack_map_is_full(struct bpf_queue_stack *qs)
+{
+	u32 head = qs->head + 1;
+
+	if (unlikely(head >= qs->size))
+		head = 0;
+
+	return head == qs->tail;
+}
+
+/* Called from syscall */
+static int queue_stack_map_alloc_check(union bpf_attr *attr)
+{
+	if (!bpf_capable())
+		return -EPERM;
+
+	/* check sanity of attributes */
+	if (attr->max_entries == 0 || attr->key_size != 0 ||
+	    attr->value_size == 0 ||
+	    attr->map_flags & ~QUEUE_STACK_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags))
+		return -EINVAL;
+
+	if (attr->value_size > KMALLOC_MAX_SIZE)
+		/* if value_size is bigger, the user space won't be able to
+		 * access the elements.
+		 */
+		return -E2BIG;
+
+	return 0;
+}
+
+static struct bpf_map *queue_stack_map_alloc(union bpf_attr *attr)
+{
+	int ret, numa_node = bpf_map_attr_numa_node(attr);
+	struct bpf_map_memory mem = {0};
+	struct bpf_queue_stack *qs;
+	u64 size, queue_size, cost;
+
+	size = (u64) attr->max_entries + 1;
+	cost = queue_size = sizeof(*qs) + size * attr->value_size;
+
+	ret = bpf_map_charge_init(&mem, cost);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	qs = bpf_map_area_alloc(queue_size, numa_node);
+	if (!qs) {
+		bpf_map_charge_finish(&mem);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	memset(qs, 0, sizeof(*qs));
+
+	bpf_map_init_from_attr(&qs->map, attr);
+
+	bpf_map_charge_move(&qs->map.memory, &mem);
+	qs->size = size;
+
+	raw_spin_lock_init(&qs->lock);
+
+	return &qs->map;
+}
+
+/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
+static void queue_stack_map_free(struct bpf_map *map)
+{
+	struct bpf_queue_stack *qs = bpf_queue_stack(map);
+
+	bpf_map_area_free(qs);
+}
+
+static int __queue_map_get(struct bpf_map *map, void *value, bool delete)
+{
+	struct bpf_queue_stack *qs = bpf_queue_stack(map);
+	unsigned long flags;
+	int err = 0;
+	void *ptr;
+
+	if (in_nmi()) {
+		if (!raw_spin_trylock_irqsave(&qs->lock, flags))
+			return -EBUSY;
+	} else {
+		raw_spin_lock_irqsave(&qs->lock, flags);
+	}
+
+	if (queue_stack_map_is_empty(qs)) {
+		memset(value, 0, qs->map.value_size);
+		err = -ENOENT;
+		goto out;
+	}
+
+	ptr = &qs->elements[qs->tail * qs->map.value_size];
+	memcpy(value, ptr, qs->map.value_size);
+
+	if (delete) {
+		if (unlikely(++qs->tail >= qs->size))
+			qs->tail = 0;
+	}
+
+out:
+	raw_spin_unlock_irqrestore(&qs->lock, flags);
+	return err;
+}
+
+
+static int __stack_map_get(struct bpf_map *map, void *value, bool delete)
+{
+	struct bpf_queue_stack *qs = bpf_queue_stack(map);
+	unsigned long flags;
+	int err = 0;
+	void *ptr;
+	u32 index;
+
+	if (in_nmi()) {
+		if (!raw_spin_trylock_irqsave(&qs->lock, flags))
+			return -EBUSY;
+	} else {
+		raw_spin_lock_irqsave(&qs->lock, flags);
+	}
+
+	if (queue_stack_map_is_empty(qs)) {
+		memset(value, 0, qs->map.value_size);
+		err = -ENOENT;
+		goto out;
+	}
+
+	index = qs->head - 1;
+	if (unlikely(index >= qs->size))
+		index = qs->size - 1;
+
+	ptr = &qs->elements[index * qs->map.value_size];
+	memcpy(value, ptr, qs->map.value_size);
+
+	if (delete)
+		qs->head = index;
+
+out:
+	raw_spin_unlock_irqrestore(&qs->lock, flags);
+	return err;
+}
+
+/* Called from syscall or from eBPF program */
+static int queue_map_peek_elem(struct bpf_map *map, void *value)
+{
+	return __queue_map_get(map, value, false);
+}
+
+/* Called from syscall or from eBPF program */
+static int stack_map_peek_elem(struct bpf_map *map, void *value)
+{
+	return __stack_map_get(map, value, false);
+}
+
+/* Called from syscall or from eBPF program */
+static int queue_map_pop_elem(struct bpf_map *map, void *value)
+{
+	return __queue_map_get(map, value, true);
+}
+
+/* Called from syscall or from eBPF program */
+static int stack_map_pop_elem(struct bpf_map *map, void *value)
+{
+	return __stack_map_get(map, value, true);
+}
+
+/* Called from syscall or from eBPF program */
+static int queue_stack_map_push_elem(struct bpf_map *map, void *value,
+				     u64 flags)
+{
+	struct bpf_queue_stack *qs = bpf_queue_stack(map);
+	unsigned long irq_flags;
+	int err = 0;
+	void *dst;
+
+	/* BPF_EXIST is used to force making room for a new element in case the
+	 * map is full
+	 */
+	bool replace = (flags & BPF_EXIST);
+
+	/* Check supported flags for queue and stack maps */
+	if (flags & BPF_NOEXIST || flags > BPF_EXIST)
+		return -EINVAL;
+
+	if (in_nmi()) {
+		if (!raw_spin_trylock_irqsave(&qs->lock, irq_flags))
+			return -EBUSY;
+	} else {
+		raw_spin_lock_irqsave(&qs->lock, irq_flags);
+	}
+
+	if (queue_stack_map_is_full(qs)) {
+		if (!replace) {
+			err = -E2BIG;
+			goto out;
+		}
+		/* advance tail pointer to overwrite oldest element */
+		if (unlikely(++qs->tail >= qs->size))
+			qs->tail = 0;
+	}
+
+	dst = &qs->elements[qs->head * qs->map.value_size];
+	memcpy(dst, value, qs->map.value_size);
+
+	if (unlikely(++qs->head >= qs->size))
+		qs->head = 0;
+
+out:
+	raw_spin_unlock_irqrestore(&qs->lock, irq_flags);
+	return err;
+}
+
+/* Called from syscall or from eBPF program */
+static void *queue_stack_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	return NULL;
+}
+
+/* Called from syscall or from eBPF program */
+static int queue_stack_map_update_elem(struct bpf_map *map, void *key,
+				       void *value, u64 flags)
+{
+	return -EINVAL;
+}
+
+/* Called from syscall or from eBPF program */
+static int queue_stack_map_delete_elem(struct bpf_map *map, void *key)
+{
+	return -EINVAL;
+}
+
+/* Called from syscall */
+static int queue_stack_map_get_next_key(struct bpf_map *map, void *key,
+					void *next_key)
+{
+	return -EINVAL;
+}
+
+static int queue_map_btf_id;
+const struct bpf_map_ops queue_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = queue_stack_map_alloc_check,
+	.map_alloc = queue_stack_map_alloc,
+	.map_free = queue_stack_map_free,
+	.map_lookup_elem = queue_stack_map_lookup_elem,
+	.map_update_elem = queue_stack_map_update_elem,
+	.map_delete_elem = queue_stack_map_delete_elem,
+	.map_push_elem = queue_stack_map_push_elem,
+	.map_pop_elem = queue_map_pop_elem,
+	.map_peek_elem = queue_map_peek_elem,
+	.map_get_next_key = queue_stack_map_get_next_key,
+	.map_btf_name = "bpf_queue_stack",
+	.map_btf_id = &queue_map_btf_id,
+};
+
+static int stack_map_btf_id;
+const struct bpf_map_ops stack_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = queue_stack_map_alloc_check,
+	.map_alloc = queue_stack_map_alloc,
+	.map_free = queue_stack_map_free,
+	.map_lookup_elem = queue_stack_map_lookup_elem,
+	.map_update_elem = queue_stack_map_update_elem,
+	.map_delete_elem = queue_stack_map_delete_elem,
+	.map_push_elem = queue_stack_map_push_elem,
+	.map_pop_elem = stack_map_pop_elem,
+	.map_peek_elem = stack_map_peek_elem,
+	.map_get_next_key = queue_stack_map_get_next_key,
+	.map_btf_name = "bpf_queue_stack",
+	.map_btf_id = &stack_map_btf_id,
+};
diff --git a/kernel/bpf/reuseport_array.c b/kernel/bpf/reuseport_array.c
new file mode 100644
index 000000000..a55cd542f
--- /dev/null
+++ b/kernel/bpf/reuseport_array.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 Facebook
+ */
+#include <linux/bpf.h>
+#include <linux/err.h>
+#include <linux/sock_diag.h>
+#include <net/sock_reuseport.h>
+
+struct reuseport_array {
+	struct bpf_map map;
+	struct sock __rcu *ptrs[];
+};
+
+static struct reuseport_array *reuseport_array(struct bpf_map *map)
+{
+	return (struct reuseport_array *)map;
+}
+
+/* The caller must hold the reuseport_lock */
+void bpf_sk_reuseport_detach(struct sock *sk)
+{
+	uintptr_t sk_user_data;
+
+	write_lock_bh(&sk->sk_callback_lock);
+	sk_user_data = (uintptr_t)sk->sk_user_data;
+	if (sk_user_data & SK_USER_DATA_BPF) {
+		struct sock __rcu **socks;
+
+		socks = (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
+		WRITE_ONCE(sk->sk_user_data, NULL);
+		/*
+		 * Do not move this NULL assignment outside of
+		 * sk->sk_callback_lock because there is
+		 * a race with reuseport_array_free()
+		 * which does not hold the reuseport_lock.
+		 */
+		RCU_INIT_POINTER(*socks, NULL);
+	}
+	write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static int reuseport_array_alloc_check(union bpf_attr *attr)
+{
+	if (attr->value_size != sizeof(u32) &&
+	    attr->value_size != sizeof(u64))
+		return -EINVAL;
+
+	return array_map_alloc_check(attr);
+}
+
+static void *reuseport_array_lookup_elem(struct bpf_map *map, void *key)
+{
+	struct reuseport_array *array = reuseport_array(map);
+	u32 index = *(u32 *)key;
+
+	if (unlikely(index >= array->map.max_entries))
+		return NULL;
+
+	return rcu_dereference(array->ptrs[index]);
+}
+
+/* Called from syscall only */
+static int reuseport_array_delete_elem(struct bpf_map *map, void *key)
+{
+	struct reuseport_array *array = reuseport_array(map);
+	u32 index = *(u32 *)key;
+	struct sock *sk;
+	int err;
+
+	if (index >= map->max_entries)
+		return -E2BIG;
+
+	if (!rcu_access_pointer(array->ptrs[index]))
+		return -ENOENT;
+
+	spin_lock_bh(&reuseport_lock);
+
+	sk = rcu_dereference_protected(array->ptrs[index],
+				       lockdep_is_held(&reuseport_lock));
+	if (sk) {
+		write_lock_bh(&sk->sk_callback_lock);
+		WRITE_ONCE(sk->sk_user_data, NULL);
+		RCU_INIT_POINTER(array->ptrs[index], NULL);
+		write_unlock_bh(&sk->sk_callback_lock);
+		err = 0;
+	} else {
+		err = -ENOENT;
+	}
+
+	spin_unlock_bh(&reuseport_lock);
+
+	return err;
+}
+
+static void reuseport_array_free(struct bpf_map *map)
+{
+	struct reuseport_array *array = reuseport_array(map);
+	struct sock *sk;
+	u32 i;
+
+	/*
+	 * ops->map_*_elem() will not be able to access this
+	 * array now. Hence, this function only races with
+	 * bpf_sk_reuseport_detach() which was triggerred by
+	 * close() or disconnect().
+	 *
+	 * This function and bpf_sk_reuseport_detach() are
+	 * both removing sk from "array".  Who removes it
+	 * first does not matter.
+	 *
+	 * The only concern here is bpf_sk_reuseport_detach()
+	 * may access "array" which is being freed here.
+	 * bpf_sk_reuseport_detach() access this "array"
+	 * through sk->sk_user_data _and_ with sk->sk_callback_lock
+	 * held which is enough because this "array" is not freed
+	 * until all sk->sk_user_data has stopped referencing this "array".
+	 *
+	 * Hence, due to the above, taking "reuseport_lock" is not
+	 * needed here.
+	 */
+
+	/*
+	 * Since reuseport_lock is not taken, sk is accessed under
+	 * rcu_read_lock()
+	 */
+	rcu_read_lock();
+	for (i = 0; i < map->max_entries; i++) {
+		sk = rcu_dereference(array->ptrs[i]);
+		if (sk) {
+			write_lock_bh(&sk->sk_callback_lock);
+			/*
+			 * No need for WRITE_ONCE(). At this point,
+			 * no one is reading it without taking the
+			 * sk->sk_callback_lock.
+			 */
+			sk->sk_user_data = NULL;
+			write_unlock_bh(&sk->sk_callback_lock);
+			RCU_INIT_POINTER(array->ptrs[i], NULL);
+		}
+	}
+	rcu_read_unlock();
+
+	/*
+	 * Once reaching here, all sk->sk_user_data is not
+	 * referenceing this "array".  "array" can be freed now.
+	 */
+	bpf_map_area_free(array);
+}
+
+static struct bpf_map *reuseport_array_alloc(union bpf_attr *attr)
+{
+	int err, numa_node = bpf_map_attr_numa_node(attr);
+	struct reuseport_array *array;
+	struct bpf_map_memory mem;
+	u64 array_size;
+
+	if (!bpf_capable())
+		return ERR_PTR(-EPERM);
+
+	array_size = sizeof(*array);
+	array_size += (u64)attr->max_entries * sizeof(struct sock *);
+
+	err = bpf_map_charge_init(&mem, array_size);
+	if (err)
+		return ERR_PTR(err);
+
+	/* allocate all map elements and zero-initialize them */
+	array = bpf_map_area_alloc(array_size, numa_node);
+	if (!array) {
+		bpf_map_charge_finish(&mem);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* copy mandatory map attributes */
+	bpf_map_init_from_attr(&array->map, attr);
+	bpf_map_charge_move(&array->map.memory, &mem);
+
+	return &array->map;
+}
+
+int bpf_fd_reuseport_array_lookup_elem(struct bpf_map *map, void *key,
+				       void *value)
+{
+	struct sock *sk;
+	int err;
+
+	if (map->value_size != sizeof(u64))
+		return -ENOSPC;
+
+	rcu_read_lock();
+	sk = reuseport_array_lookup_elem(map, key);
+	if (sk) {
+		*(u64 *)value = __sock_gen_cookie(sk);
+		err = 0;
+	} else {
+		err = -ENOENT;
+	}
+	rcu_read_unlock();
+
+	return err;
+}
+
+static int
+reuseport_array_update_check(const struct reuseport_array *array,
+			     const struct sock *nsk,
+			     const struct sock *osk,
+			     const struct sock_reuseport *nsk_reuse,
+			     u32 map_flags)
+{
+	if (osk && map_flags == BPF_NOEXIST)
+		return -EEXIST;
+
+	if (!osk && map_flags == BPF_EXIST)
+		return -ENOENT;
+
+	if (nsk->sk_protocol != IPPROTO_UDP && nsk->sk_protocol != IPPROTO_TCP)
+		return -ENOTSUPP;
+
+	if (nsk->sk_family != AF_INET && nsk->sk_family != AF_INET6)
+		return -ENOTSUPP;
+
+	if (nsk->sk_type != SOCK_STREAM && nsk->sk_type != SOCK_DGRAM)
+		return -ENOTSUPP;
+
+	/*
+	 * sk must be hashed (i.e. listening in the TCP case or binded
+	 * in the UDP case) and
+	 * it must also be a SO_REUSEPORT sk (i.e. reuse cannot be NULL).
+	 *
+	 * Also, sk will be used in bpf helper that is protected by
+	 * rcu_read_lock().
+	 */
+	if (!sock_flag(nsk, SOCK_RCU_FREE) || !sk_hashed(nsk) || !nsk_reuse)
+		return -EINVAL;
+
+	/* READ_ONCE because the sk->sk_callback_lock may not be held here */
+	if (READ_ONCE(nsk->sk_user_data))
+		return -EBUSY;
+
+	return 0;
+}
+
+/*
+ * Called from syscall only.
+ * The "nsk" in the fd refcnt.
+ * The "osk" and "reuse" are protected by reuseport_lock.
+ */
+int bpf_fd_reuseport_array_update_elem(struct bpf_map *map, void *key,
+				       void *value, u64 map_flags)
+{
+	struct reuseport_array *array = reuseport_array(map);
+	struct sock *free_osk = NULL, *osk, *nsk;
+	struct sock_reuseport *reuse;
+	u32 index = *(u32 *)key;
+	uintptr_t sk_user_data;
+	struct socket *socket;
+	int err, fd;
+
+	if (map_flags > BPF_EXIST)
+		return -EINVAL;
+
+	if (index >= map->max_entries)
+		return -E2BIG;
+
+	if (map->value_size == sizeof(u64)) {
+		u64 fd64 = *(u64 *)value;
+
+		if (fd64 > S32_MAX)
+			return -EINVAL;
+		fd = fd64;
+	} else {
+		fd = *(int *)value;
+	}
+
+	socket = sockfd_lookup(fd, &err);
+	if (!socket)
+		return err;
+
+	nsk = socket->sk;
+	if (!nsk) {
+		err = -EINVAL;
+		goto put_file;
+	}
+
+	/* Quick checks before taking reuseport_lock */
+	err = reuseport_array_update_check(array, nsk,
+					   rcu_access_pointer(array->ptrs[index]),
+					   rcu_access_pointer(nsk->sk_reuseport_cb),
+					   map_flags);
+	if (err)
+		goto put_file;
+
+	spin_lock_bh(&reuseport_lock);
+	/*
+	 * Some of the checks only need reuseport_lock
+	 * but it is done under sk_callback_lock also
+	 * for simplicity reason.
+	 */
+	write_lock_bh(&nsk->sk_callback_lock);
+
+	osk = rcu_dereference_protected(array->ptrs[index],
+					lockdep_is_held(&reuseport_lock));
+	reuse = rcu_dereference_protected(nsk->sk_reuseport_cb,
+					  lockdep_is_held(&reuseport_lock));
+	err = reuseport_array_update_check(array, nsk, osk, reuse, map_flags);
+	if (err)
+		goto put_file_unlock;
+
+	sk_user_data = (uintptr_t)&array->ptrs[index] | SK_USER_DATA_NOCOPY |
+		SK_USER_DATA_BPF;
+	WRITE_ONCE(nsk->sk_user_data, (void *)sk_user_data);
+	rcu_assign_pointer(array->ptrs[index], nsk);
+	free_osk = osk;
+	err = 0;
+
+put_file_unlock:
+	write_unlock_bh(&nsk->sk_callback_lock);
+
+	if (free_osk) {
+		write_lock_bh(&free_osk->sk_callback_lock);
+		WRITE_ONCE(free_osk->sk_user_data, NULL);
+		write_unlock_bh(&free_osk->sk_callback_lock);
+	}
+
+	spin_unlock_bh(&reuseport_lock);
+put_file:
+	fput(socket->file);
+	return err;
+}
+
+/* Called from syscall */
+static int reuseport_array_get_next_key(struct bpf_map *map, void *key,
+					void *next_key)
+{
+	struct reuseport_array *array = reuseport_array(map);
+	u32 index = key ? *(u32 *)key : U32_MAX;
+	u32 *next = (u32 *)next_key;
+
+	if (index >= array->map.max_entries) {
+		*next = 0;
+		return 0;
+	}
+
+	if (index == array->map.max_entries - 1)
+		return -ENOENT;
+
+	*next = index + 1;
+	return 0;
+}
+
+static int reuseport_array_map_btf_id;
+const struct bpf_map_ops reuseport_array_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc_check = reuseport_array_alloc_check,
+	.map_alloc = reuseport_array_alloc,
+	.map_free = reuseport_array_free,
+	.map_lookup_elem = reuseport_array_lookup_elem,
+	.map_get_next_key = reuseport_array_get_next_key,
+	.map_delete_elem = reuseport_array_delete_elem,
+	.map_btf_name = "reuseport_array",
+	.map_btf_id = &reuseport_array_map_btf_id,
+};
diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c
new file mode 100644
index 000000000..1e4bf2352
--- /dev/null
+++ b/kernel/bpf/ringbuf.c
@@ -0,0 +1,496 @@
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/err.h>
+#include <linux/irq_work.h>
+#include <linux/slab.h>
+#include <linux/filter.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <linux/poll.h>
+#include <linux/kmemleak.h>
+#include <uapi/linux/btf.h>
+
+#define RINGBUF_CREATE_FLAG_MASK (BPF_F_NUMA_NODE)
+
+/* non-mmap()'able part of bpf_ringbuf (everything up to consumer page) */
+#define RINGBUF_PGOFF \
+	(offsetof(struct bpf_ringbuf, consumer_pos) >> PAGE_SHIFT)
+/* consumer page and producer page */
+#define RINGBUF_POS_PAGES 2
+
+#define RINGBUF_MAX_RECORD_SZ (UINT_MAX/4)
+
+/* Maximum size of ring buffer area is limited by 32-bit page offset within
+ * record header, counted in pages. Reserve 8 bits for extensibility, and take
+ * into account few extra pages for consumer/producer pages and
+ * non-mmap()'able parts. This gives 64GB limit, which seems plenty for single
+ * ring buffer.
+ */
+#define RINGBUF_MAX_DATA_SZ \
+	(((1ULL << 24) - RINGBUF_POS_PAGES - RINGBUF_PGOFF) * PAGE_SIZE)
+
+struct bpf_ringbuf {
+	wait_queue_head_t waitq;
+	struct irq_work work;
+	u64 mask;
+	struct page **pages;
+	int nr_pages;
+	spinlock_t spinlock ____cacheline_aligned_in_smp;
+	/* Consumer and producer counters are put into separate pages to allow
+	 * mapping consumer page as r/w, but restrict producer page to r/o.
+	 * This protects producer position from being modified by user-space
+	 * application and ruining in-kernel position tracking.
+	 */
+	unsigned long consumer_pos __aligned(PAGE_SIZE);
+	unsigned long producer_pos __aligned(PAGE_SIZE);
+	char data[] __aligned(PAGE_SIZE);
+};
+
+struct bpf_ringbuf_map {
+	struct bpf_map map;
+	struct bpf_map_memory memory;
+	struct bpf_ringbuf *rb;
+};
+
+/* 8-byte ring buffer record header structure */
+struct bpf_ringbuf_hdr {
+	u32 len;
+	u32 pg_off;
+};
+
+static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node)
+{
+	const gfp_t flags = GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN |
+			    __GFP_ZERO;
+	int nr_meta_pages = RINGBUF_PGOFF + RINGBUF_POS_PAGES;
+	int nr_data_pages = data_sz >> PAGE_SHIFT;
+	int nr_pages = nr_meta_pages + nr_data_pages;
+	struct page **pages, *page;
+	struct bpf_ringbuf *rb;
+	size_t array_size;
+	int i;
+
+	/* Each data page is mapped twice to allow "virtual"
+	 * continuous read of samples wrapping around the end of ring
+	 * buffer area:
+	 * ------------------------------------------------------
+	 * | meta pages |  real data pages  |  same data pages  |
+	 * ------------------------------------------------------
+	 * |            | 1 2 3 4 5 6 7 8 9 | 1 2 3 4 5 6 7 8 9 |
+	 * ------------------------------------------------------
+	 * |            | TA             DA | TA             DA |
+	 * ------------------------------------------------------
+	 *                               ^^^^^^^
+	 *                                  |
+	 * Here, no need to worry about special handling of wrapped-around
+	 * data due to double-mapped data pages. This works both in kernel and
+	 * when mmap()'ed in user-space, simplifying both kernel and
+	 * user-space implementations significantly.
+	 */
+	array_size = (nr_meta_pages + 2 * nr_data_pages) * sizeof(*pages);
+	if (array_size > PAGE_SIZE)
+		pages = vmalloc_node(array_size, numa_node);
+	else
+		pages = kmalloc_node(array_size, flags, numa_node);
+	if (!pages)
+		return NULL;
+
+	for (i = 0; i < nr_pages; i++) {
+		page = alloc_pages_node(numa_node, flags, 0);
+		if (!page) {
+			nr_pages = i;
+			goto err_free_pages;
+		}
+		pages[i] = page;
+		if (i >= nr_meta_pages)
+			pages[nr_data_pages + i] = page;
+	}
+
+	rb = vmap(pages, nr_meta_pages + 2 * nr_data_pages,
+		  VM_MAP | VM_USERMAP, PAGE_KERNEL);
+	if (rb) {
+		kmemleak_not_leak(pages);
+		rb->pages = pages;
+		rb->nr_pages = nr_pages;
+		return rb;
+	}
+
+err_free_pages:
+	for (i = 0; i < nr_pages; i++)
+		__free_page(pages[i]);
+	kvfree(pages);
+	return NULL;
+}
+
+static void bpf_ringbuf_notify(struct irq_work *work)
+{
+	struct bpf_ringbuf *rb = container_of(work, struct bpf_ringbuf, work);
+
+	wake_up_all(&rb->waitq);
+}
+
+static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node)
+{
+	struct bpf_ringbuf *rb;
+
+	rb = bpf_ringbuf_area_alloc(data_sz, numa_node);
+	if (!rb)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock_init(&rb->spinlock);
+	init_waitqueue_head(&rb->waitq);
+	init_irq_work(&rb->work, bpf_ringbuf_notify);
+
+	rb->mask = data_sz - 1;
+	rb->consumer_pos = 0;
+	rb->producer_pos = 0;
+
+	return rb;
+}
+
+static struct bpf_map *ringbuf_map_alloc(union bpf_attr *attr)
+{
+	struct bpf_ringbuf_map *rb_map;
+	u64 cost;
+	int err;
+
+	if (attr->map_flags & ~RINGBUF_CREATE_FLAG_MASK)
+		return ERR_PTR(-EINVAL);
+
+	if (attr->key_size || attr->value_size ||
+	    !is_power_of_2(attr->max_entries) ||
+	    !PAGE_ALIGNED(attr->max_entries))
+		return ERR_PTR(-EINVAL);
+
+#ifdef CONFIG_64BIT
+	/* on 32-bit arch, it's impossible to overflow record's hdr->pgoff */
+	if (attr->max_entries > RINGBUF_MAX_DATA_SZ)
+		return ERR_PTR(-E2BIG);
+#endif
+
+	rb_map = kzalloc(sizeof(*rb_map), GFP_USER);
+	if (!rb_map)
+		return ERR_PTR(-ENOMEM);
+
+	bpf_map_init_from_attr(&rb_map->map, attr);
+
+	cost = sizeof(struct bpf_ringbuf_map) +
+	       sizeof(struct bpf_ringbuf) +
+	       attr->max_entries;
+	err = bpf_map_charge_init(&rb_map->map.memory, cost);
+	if (err)
+		goto err_free_map;
+
+	rb_map->rb = bpf_ringbuf_alloc(attr->max_entries, rb_map->map.numa_node);
+	if (IS_ERR(rb_map->rb)) {
+		err = PTR_ERR(rb_map->rb);
+		goto err_uncharge;
+	}
+
+	return &rb_map->map;
+
+err_uncharge:
+	bpf_map_charge_finish(&rb_map->map.memory);
+err_free_map:
+	kfree(rb_map);
+	return ERR_PTR(err);
+}
+
+static void bpf_ringbuf_free(struct bpf_ringbuf *rb)
+{
+	/* copy pages pointer and nr_pages to local variable, as we are going
+	 * to unmap rb itself with vunmap() below
+	 */
+	struct page **pages = rb->pages;
+	int i, nr_pages = rb->nr_pages;
+
+	vunmap(rb);
+	for (i = 0; i < nr_pages; i++)
+		__free_page(pages[i]);
+	kvfree(pages);
+}
+
+static void ringbuf_map_free(struct bpf_map *map)
+{
+	struct bpf_ringbuf_map *rb_map;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+	bpf_ringbuf_free(rb_map->rb);
+	kfree(rb_map);
+}
+
+static void *ringbuf_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	return ERR_PTR(-ENOTSUPP);
+}
+
+static int ringbuf_map_update_elem(struct bpf_map *map, void *key, void *value,
+				   u64 flags)
+{
+	return -ENOTSUPP;
+}
+
+static int ringbuf_map_delete_elem(struct bpf_map *map, void *key)
+{
+	return -ENOTSUPP;
+}
+
+static int ringbuf_map_get_next_key(struct bpf_map *map, void *key,
+				    void *next_key)
+{
+	return -ENOTSUPP;
+}
+
+static int ringbuf_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
+{
+	struct bpf_ringbuf_map *rb_map;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+
+	if (vma->vm_flags & VM_WRITE) {
+		/* allow writable mapping for the consumer_pos only */
+		if (vma->vm_pgoff != 0 || vma->vm_end - vma->vm_start != PAGE_SIZE)
+			return -EPERM;
+	} else {
+		vma->vm_flags &= ~VM_MAYWRITE;
+	}
+	/* remap_vmalloc_range() checks size and offset constraints */
+	return remap_vmalloc_range(vma, rb_map->rb,
+				   vma->vm_pgoff + RINGBUF_PGOFF);
+}
+
+static unsigned long ringbuf_avail_data_sz(struct bpf_ringbuf *rb)
+{
+	unsigned long cons_pos, prod_pos;
+
+	cons_pos = smp_load_acquire(&rb->consumer_pos);
+	prod_pos = smp_load_acquire(&rb->producer_pos);
+	return prod_pos - cons_pos;
+}
+
+static __poll_t ringbuf_map_poll(struct bpf_map *map, struct file *filp,
+				 struct poll_table_struct *pts)
+{
+	struct bpf_ringbuf_map *rb_map;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+	poll_wait(filp, &rb_map->rb->waitq, pts);
+
+	if (ringbuf_avail_data_sz(rb_map->rb))
+		return EPOLLIN | EPOLLRDNORM;
+	return 0;
+}
+
+static int ringbuf_map_btf_id;
+const struct bpf_map_ops ringbuf_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc = ringbuf_map_alloc,
+	.map_free = ringbuf_map_free,
+	.map_mmap = ringbuf_map_mmap,
+	.map_poll = ringbuf_map_poll,
+	.map_lookup_elem = ringbuf_map_lookup_elem,
+	.map_update_elem = ringbuf_map_update_elem,
+	.map_delete_elem = ringbuf_map_delete_elem,
+	.map_get_next_key = ringbuf_map_get_next_key,
+	.map_btf_name = "bpf_ringbuf_map",
+	.map_btf_id = &ringbuf_map_btf_id,
+};
+
+/* Given pointer to ring buffer record metadata and struct bpf_ringbuf itself,
+ * calculate offset from record metadata to ring buffer in pages, rounded
+ * down. This page offset is stored as part of record metadata and allows to
+ * restore struct bpf_ringbuf * from record pointer. This page offset is
+ * stored at offset 4 of record metadata header.
+ */
+static size_t bpf_ringbuf_rec_pg_off(struct bpf_ringbuf *rb,
+				     struct bpf_ringbuf_hdr *hdr)
+{
+	return ((void *)hdr - (void *)rb) >> PAGE_SHIFT;
+}
+
+/* Given pointer to ring buffer record header, restore pointer to struct
+ * bpf_ringbuf itself by using page offset stored at offset 4
+ */
+static struct bpf_ringbuf *
+bpf_ringbuf_restore_from_rec(struct bpf_ringbuf_hdr *hdr)
+{
+	unsigned long addr = (unsigned long)(void *)hdr;
+	unsigned long off = (unsigned long)hdr->pg_off << PAGE_SHIFT;
+
+	return (void*)((addr & PAGE_MASK) - off);
+}
+
+static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size)
+{
+	unsigned long cons_pos, prod_pos, new_prod_pos, flags;
+	u32 len, pg_off;
+	struct bpf_ringbuf_hdr *hdr;
+
+	if (unlikely(size > RINGBUF_MAX_RECORD_SZ))
+		return NULL;
+
+	len = round_up(size + BPF_RINGBUF_HDR_SZ, 8);
+	if (len > rb->mask + 1)
+		return NULL;
+
+	cons_pos = smp_load_acquire(&rb->consumer_pos);
+
+	if (in_nmi()) {
+		if (!spin_trylock_irqsave(&rb->spinlock, flags))
+			return NULL;
+	} else {
+		spin_lock_irqsave(&rb->spinlock, flags);
+	}
+
+	prod_pos = rb->producer_pos;
+	new_prod_pos = prod_pos + len;
+
+	/* check for out of ringbuf space by ensuring producer position
+	 * doesn't advance more than (ringbuf_size - 1) ahead
+	 */
+	if (new_prod_pos - cons_pos > rb->mask) {
+		spin_unlock_irqrestore(&rb->spinlock, flags);
+		return NULL;
+	}
+
+	hdr = (void *)rb->data + (prod_pos & rb->mask);
+	pg_off = bpf_ringbuf_rec_pg_off(rb, hdr);
+	hdr->len = size | BPF_RINGBUF_BUSY_BIT;
+	hdr->pg_off = pg_off;
+
+	/* pairs with consumer's smp_load_acquire() */
+	smp_store_release(&rb->producer_pos, new_prod_pos);
+
+	spin_unlock_irqrestore(&rb->spinlock, flags);
+
+	return (void *)hdr + BPF_RINGBUF_HDR_SZ;
+}
+
+BPF_CALL_3(bpf_ringbuf_reserve, struct bpf_map *, map, u64, size, u64, flags)
+{
+	struct bpf_ringbuf_map *rb_map;
+
+	if (unlikely(flags))
+		return 0;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+	return (unsigned long)__bpf_ringbuf_reserve(rb_map->rb, size);
+}
+
+const struct bpf_func_proto bpf_ringbuf_reserve_proto = {
+	.func		= bpf_ringbuf_reserve,
+	.ret_type	= RET_PTR_TO_ALLOC_MEM_OR_NULL,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_CONST_ALLOC_SIZE_OR_ZERO,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+static void bpf_ringbuf_commit(void *sample, u64 flags, bool discard)
+{
+	unsigned long rec_pos, cons_pos;
+	struct bpf_ringbuf_hdr *hdr;
+	struct bpf_ringbuf *rb;
+	u32 new_len;
+
+	hdr = sample - BPF_RINGBUF_HDR_SZ;
+	rb = bpf_ringbuf_restore_from_rec(hdr);
+	new_len = hdr->len ^ BPF_RINGBUF_BUSY_BIT;
+	if (discard)
+		new_len |= BPF_RINGBUF_DISCARD_BIT;
+
+	/* update record header with correct final size prefix */
+	xchg(&hdr->len, new_len);
+
+	/* if consumer caught up and is waiting for our record, notify about
+	 * new data availability
+	 */
+	rec_pos = (void *)hdr - (void *)rb->data;
+	cons_pos = smp_load_acquire(&rb->consumer_pos) & rb->mask;
+
+	if (flags & BPF_RB_FORCE_WAKEUP)
+		irq_work_queue(&rb->work);
+	else if (cons_pos == rec_pos && !(flags & BPF_RB_NO_WAKEUP))
+		irq_work_queue(&rb->work);
+}
+
+BPF_CALL_2(bpf_ringbuf_submit, void *, sample, u64, flags)
+{
+	bpf_ringbuf_commit(sample, flags, false /* discard */);
+	return 0;
+}
+
+const struct bpf_func_proto bpf_ringbuf_submit_proto = {
+	.func		= bpf_ringbuf_submit,
+	.ret_type	= RET_VOID,
+	.arg1_type	= ARG_PTR_TO_ALLOC_MEM,
+	.arg2_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_ringbuf_discard, void *, sample, u64, flags)
+{
+	bpf_ringbuf_commit(sample, flags, true /* discard */);
+	return 0;
+}
+
+const struct bpf_func_proto bpf_ringbuf_discard_proto = {
+	.func		= bpf_ringbuf_discard,
+	.ret_type	= RET_VOID,
+	.arg1_type	= ARG_PTR_TO_ALLOC_MEM,
+	.arg2_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_4(bpf_ringbuf_output, struct bpf_map *, map, void *, data, u64, size,
+	   u64, flags)
+{
+	struct bpf_ringbuf_map *rb_map;
+	void *rec;
+
+	if (unlikely(flags & ~(BPF_RB_NO_WAKEUP | BPF_RB_FORCE_WAKEUP)))
+		return -EINVAL;
+
+	rb_map = container_of(map, struct bpf_ringbuf_map, map);
+	rec = __bpf_ringbuf_reserve(rb_map->rb, size);
+	if (!rec)
+		return -EAGAIN;
+
+	memcpy(rec, data, size);
+	bpf_ringbuf_commit(rec, flags, false /* discard */);
+	return 0;
+}
+
+const struct bpf_func_proto bpf_ringbuf_output_proto = {
+	.func		= bpf_ringbuf_output,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_ringbuf_query, struct bpf_map *, map, u64, flags)
+{
+	struct bpf_ringbuf *rb;
+
+	rb = container_of(map, struct bpf_ringbuf_map, map)->rb;
+
+	switch (flags) {
+	case BPF_RB_AVAIL_DATA:
+		return ringbuf_avail_data_sz(rb);
+	case BPF_RB_RING_SIZE:
+		return rb->mask + 1;
+	case BPF_RB_CONS_POS:
+		return smp_load_acquire(&rb->consumer_pos);
+	case BPF_RB_PROD_POS:
+		return smp_load_acquire(&rb->producer_pos);
+	default:
+		return 0;
+	}
+}
+
+const struct bpf_func_proto bpf_ringbuf_query_proto = {
+	.func		= bpf_ringbuf_query,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_ANYTHING,
+};
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
new file mode 100644
index 000000000..b8afea2ce
--- /dev/null
+++ b/kernel/bpf/stackmap.c
@@ -0,0 +1,877 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <linux/bpf.h>
+#include <linux/jhash.h>
+#include <linux/filter.h>
+#include <linux/kernel.h>
+#include <linux/stacktrace.h>
+#include <linux/perf_event.h>
+#include <linux/elf.h>
+#include <linux/pagemap.h>
+#include <linux/irq_work.h>
+#include <linux/btf_ids.h>
+#include "percpu_freelist.h"
+
+#define STACK_CREATE_FLAG_MASK					\
+	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY |	\
+	 BPF_F_STACK_BUILD_ID)
+
+struct stack_map_bucket {
+	struct pcpu_freelist_node fnode;
+	u32 hash;
+	u32 nr;
+	u64 data[];
+};
+
+struct bpf_stack_map {
+	struct bpf_map map;
+	void *elems;
+	struct pcpu_freelist freelist;
+	u32 n_buckets;
+	struct stack_map_bucket *buckets[];
+};
+
+/* irq_work to run up_read() for build_id lookup in nmi context */
+struct stack_map_irq_work {
+	struct irq_work irq_work;
+	struct mm_struct *mm;
+};
+
+static void do_up_read(struct irq_work *entry)
+{
+	struct stack_map_irq_work *work;
+
+	if (WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_RT)))
+		return;
+
+	work = container_of(entry, struct stack_map_irq_work, irq_work);
+	mmap_read_unlock_non_owner(work->mm);
+}
+
+static DEFINE_PER_CPU(struct stack_map_irq_work, up_read_work);
+
+static inline bool stack_map_use_build_id(struct bpf_map *map)
+{
+	return (map->map_flags & BPF_F_STACK_BUILD_ID);
+}
+
+static inline int stack_map_data_size(struct bpf_map *map)
+{
+	return stack_map_use_build_id(map) ?
+		sizeof(struct bpf_stack_build_id) : sizeof(u64);
+}
+
+static int prealloc_elems_and_freelist(struct bpf_stack_map *smap)
+{
+	u64 elem_size = sizeof(struct stack_map_bucket) +
+			(u64)smap->map.value_size;
+	int err;
+
+	smap->elems = bpf_map_area_alloc(elem_size * smap->map.max_entries,
+					 smap->map.numa_node);
+	if (!smap->elems)
+		return -ENOMEM;
+
+	err = pcpu_freelist_init(&smap->freelist);
+	if (err)
+		goto free_elems;
+
+	pcpu_freelist_populate(&smap->freelist, smap->elems, elem_size,
+			       smap->map.max_entries);
+	return 0;
+
+free_elems:
+	bpf_map_area_free(smap->elems);
+	return err;
+}
+
+/* Called from syscall */
+static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
+{
+	u32 value_size = attr->value_size;
+	struct bpf_stack_map *smap;
+	struct bpf_map_memory mem;
+	u64 cost, n_buckets;
+	int err;
+
+	if (!bpf_capable())
+		return ERR_PTR(-EPERM);
+
+	if (attr->map_flags & ~STACK_CREATE_FLAG_MASK)
+		return ERR_PTR(-EINVAL);
+
+	/* check sanity of attributes */
+	if (attr->max_entries == 0 || attr->key_size != 4 ||
+	    value_size < 8 || value_size % 8)
+		return ERR_PTR(-EINVAL);
+
+	BUILD_BUG_ON(sizeof(struct bpf_stack_build_id) % sizeof(u64));
+	if (attr->map_flags & BPF_F_STACK_BUILD_ID) {
+		if (value_size % sizeof(struct bpf_stack_build_id) ||
+		    value_size / sizeof(struct bpf_stack_build_id)
+		    > sysctl_perf_event_max_stack)
+			return ERR_PTR(-EINVAL);
+	} else if (value_size / 8 > sysctl_perf_event_max_stack)
+		return ERR_PTR(-EINVAL);
+
+	/* hash table size must be power of 2 */
+	n_buckets = roundup_pow_of_two(attr->max_entries);
+	if (!n_buckets)
+		return ERR_PTR(-E2BIG);
+
+	cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap);
+	err = bpf_map_charge_init(&mem, cost + attr->max_entries *
+			   (sizeof(struct stack_map_bucket) + (u64)value_size));
+	if (err)
+		return ERR_PTR(err);
+
+	smap = bpf_map_area_alloc(cost, bpf_map_attr_numa_node(attr));
+	if (!smap) {
+		bpf_map_charge_finish(&mem);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	bpf_map_init_from_attr(&smap->map, attr);
+	smap->map.value_size = value_size;
+	smap->n_buckets = n_buckets;
+
+	err = get_callchain_buffers(sysctl_perf_event_max_stack);
+	if (err)
+		goto free_charge;
+
+	err = prealloc_elems_and_freelist(smap);
+	if (err)
+		goto put_buffers;
+
+	bpf_map_charge_move(&smap->map.memory, &mem);
+
+	return &smap->map;
+
+put_buffers:
+	put_callchain_buffers();
+free_charge:
+	bpf_map_charge_finish(&mem);
+	bpf_map_area_free(smap);
+	return ERR_PTR(err);
+}
+
+#define BPF_BUILD_ID 3
+/*
+ * Parse build id from the note segment. This logic can be shared between
+ * 32-bit and 64-bit system, because Elf32_Nhdr and Elf64_Nhdr are
+ * identical.
+ */
+static inline int stack_map_parse_build_id(void *page_addr,
+					   unsigned char *build_id,
+					   void *note_start,
+					   Elf32_Word note_size)
+{
+	Elf32_Word note_offs = 0, new_offs;
+
+	/* check for overflow */
+	if (note_start < page_addr || note_start + note_size < note_start)
+		return -EINVAL;
+
+	/* only supports note that fits in the first page */
+	if (note_start + note_size > page_addr + PAGE_SIZE)
+		return -EINVAL;
+
+	while (note_offs + sizeof(Elf32_Nhdr) < note_size) {
+		Elf32_Nhdr *nhdr = (Elf32_Nhdr *)(note_start + note_offs);
+
+		if (nhdr->n_type == BPF_BUILD_ID &&
+		    nhdr->n_namesz == sizeof("GNU") &&
+		    nhdr->n_descsz > 0 &&
+		    nhdr->n_descsz <= BPF_BUILD_ID_SIZE) {
+			memcpy(build_id,
+			       note_start + note_offs +
+			       ALIGN(sizeof("GNU"), 4) + sizeof(Elf32_Nhdr),
+			       nhdr->n_descsz);
+			memset(build_id + nhdr->n_descsz, 0,
+			       BPF_BUILD_ID_SIZE - nhdr->n_descsz);
+			return 0;
+		}
+		new_offs = note_offs + sizeof(Elf32_Nhdr) +
+			ALIGN(nhdr->n_namesz, 4) + ALIGN(nhdr->n_descsz, 4);
+		if (new_offs <= note_offs)  /* overflow */
+			break;
+		note_offs = new_offs;
+	}
+	return -EINVAL;
+}
+
+/* Parse build ID from 32-bit ELF */
+static int stack_map_get_build_id_32(void *page_addr,
+				     unsigned char *build_id)
+{
+	Elf32_Ehdr *ehdr = (Elf32_Ehdr *)page_addr;
+	Elf32_Phdr *phdr;
+	int i;
+
+	/* only supports phdr that fits in one page */
+	if (ehdr->e_phnum >
+	    (PAGE_SIZE - sizeof(Elf32_Ehdr)) / sizeof(Elf32_Phdr))
+		return -EINVAL;
+
+	phdr = (Elf32_Phdr *)(page_addr + sizeof(Elf32_Ehdr));
+
+	for (i = 0; i < ehdr->e_phnum; ++i) {
+		if (phdr[i].p_type == PT_NOTE &&
+		    !stack_map_parse_build_id(page_addr, build_id,
+					      page_addr + phdr[i].p_offset,
+					      phdr[i].p_filesz))
+			return 0;
+	}
+	return -EINVAL;
+}
+
+/* Parse build ID from 64-bit ELF */
+static int stack_map_get_build_id_64(void *page_addr,
+				     unsigned char *build_id)
+{
+	Elf64_Ehdr *ehdr = (Elf64_Ehdr *)page_addr;
+	Elf64_Phdr *phdr;
+	int i;
+
+	/* only supports phdr that fits in one page */
+	if (ehdr->e_phnum >
+	    (PAGE_SIZE - sizeof(Elf64_Ehdr)) / sizeof(Elf64_Phdr))
+		return -EINVAL;
+
+	phdr = (Elf64_Phdr *)(page_addr + sizeof(Elf64_Ehdr));
+
+	for (i = 0; i < ehdr->e_phnum; ++i) {
+		if (phdr[i].p_type == PT_NOTE &&
+		    !stack_map_parse_build_id(page_addr, build_id,
+					      page_addr + phdr[i].p_offset,
+					      phdr[i].p_filesz))
+			return 0;
+	}
+	return -EINVAL;
+}
+
+/* Parse build ID of ELF file mapped to vma */
+static int stack_map_get_build_id(struct vm_area_struct *vma,
+				  unsigned char *build_id)
+{
+	Elf32_Ehdr *ehdr;
+	struct page *page;
+	void *page_addr;
+	int ret;
+
+	/* only works for page backed storage  */
+	if (!vma->vm_file)
+		return -EINVAL;
+
+	page = find_get_page(vma->vm_file->f_mapping, 0);
+	if (!page)
+		return -EFAULT;	/* page not mapped */
+
+	ret = -EINVAL;
+	page_addr = kmap_atomic(page);
+	ehdr = (Elf32_Ehdr *)page_addr;
+
+	/* compare magic x7f "ELF" */
+	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0)
+		goto out;
+
+	/* only support executable file and shared object file */
+	if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN)
+		goto out;
+
+	if (ehdr->e_ident[EI_CLASS] == ELFCLASS32)
+		ret = stack_map_get_build_id_32(page_addr, build_id);
+	else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
+		ret = stack_map_get_build_id_64(page_addr, build_id);
+out:
+	kunmap_atomic(page_addr);
+	put_page(page);
+	return ret;
+}
+
+static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
+					  u64 *ips, u32 trace_nr, bool user)
+{
+	int i;
+	struct vm_area_struct *vma;
+	bool irq_work_busy = false;
+	struct stack_map_irq_work *work = NULL;
+
+	if (irqs_disabled()) {
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+			work = this_cpu_ptr(&up_read_work);
+			if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY) {
+				/* cannot queue more up_read, fallback */
+				irq_work_busy = true;
+			}
+		} else {
+			/*
+			 * PREEMPT_RT does not allow to trylock mmap sem in
+			 * interrupt disabled context. Force the fallback code.
+			 */
+			irq_work_busy = true;
+		}
+	}
+
+	/*
+	 * We cannot do up_read() when the irq is disabled, because of
+	 * risk to deadlock with rq_lock. To do build_id lookup when the
+	 * irqs are disabled, we need to run up_read() in irq_work. We use
+	 * a percpu variable to do the irq_work. If the irq_work is
+	 * already used by another lookup, we fall back to report ips.
+	 *
+	 * Same fallback is used for kernel stack (!user) on a stackmap
+	 * with build_id.
+	 */
+	if (!user || !current || !current->mm || irq_work_busy ||
+	    !mmap_read_trylock_non_owner(current->mm)) {
+		/* cannot access current->mm, fall back to ips */
+		for (i = 0; i < trace_nr; i++) {
+			id_offs[i].status = BPF_STACK_BUILD_ID_IP;
+			id_offs[i].ip = ips[i];
+			memset(id_offs[i].build_id, 0, BPF_BUILD_ID_SIZE);
+		}
+		return;
+	}
+
+	for (i = 0; i < trace_nr; i++) {
+		vma = find_vma(current->mm, ips[i]);
+		if (!vma || stack_map_get_build_id(vma, id_offs[i].build_id)) {
+			/* per entry fall back to ips */
+			id_offs[i].status = BPF_STACK_BUILD_ID_IP;
+			id_offs[i].ip = ips[i];
+			memset(id_offs[i].build_id, 0, BPF_BUILD_ID_SIZE);
+			continue;
+		}
+		id_offs[i].offset = (vma->vm_pgoff << PAGE_SHIFT) + ips[i]
+			- vma->vm_start;
+		id_offs[i].status = BPF_STACK_BUILD_ID_VALID;
+	}
+
+	if (!work) {
+		mmap_read_unlock_non_owner(current->mm);
+	} else {
+		work->mm = current->mm;
+		irq_work_queue(&work->irq_work);
+	}
+}
+
+static struct perf_callchain_entry *
+get_callchain_entry_for_task(struct task_struct *task, u32 max_depth)
+{
+#ifdef CONFIG_STACKTRACE
+	struct perf_callchain_entry *entry;
+	int rctx;
+
+	entry = get_callchain_entry(&rctx);
+
+	if (!entry)
+		return NULL;
+
+	entry->nr = stack_trace_save_tsk(task, (unsigned long *)entry->ip,
+					 max_depth, 0);
+
+	/* stack_trace_save_tsk() works on unsigned long array, while
+	 * perf_callchain_entry uses u64 array. For 32-bit systems, it is
+	 * necessary to fix this mismatch.
+	 */
+	if (__BITS_PER_LONG != 64) {
+		unsigned long *from = (unsigned long *) entry->ip;
+		u64 *to = entry->ip;
+		int i;
+
+		/* copy data from the end to avoid using extra buffer */
+		for (i = entry->nr - 1; i >= 0; i--)
+			to[i] = (u64)(from[i]);
+	}
+
+	put_callchain_entry(rctx);
+
+	return entry;
+#else /* CONFIG_STACKTRACE */
+	return NULL;
+#endif
+}
+
+static long __bpf_get_stackid(struct bpf_map *map,
+			      struct perf_callchain_entry *trace, u64 flags)
+{
+	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+	struct stack_map_bucket *bucket, *new_bucket, *old_bucket;
+	u32 skip = flags & BPF_F_SKIP_FIELD_MASK;
+	u32 hash, id, trace_nr, trace_len;
+	bool user = flags & BPF_F_USER_STACK;
+	u64 *ips;
+	bool hash_matches;
+
+	if (trace->nr <= skip)
+		/* skipping more than usable stack trace */
+		return -EFAULT;
+
+	trace_nr = trace->nr - skip;
+	trace_len = trace_nr * sizeof(u64);
+	ips = trace->ip + skip;
+	hash = jhash2((u32 *)ips, trace_len / sizeof(u32), 0);
+	id = hash & (smap->n_buckets - 1);
+	bucket = READ_ONCE(smap->buckets[id]);
+
+	hash_matches = bucket && bucket->hash == hash;
+	/* fast cmp */
+	if (hash_matches && flags & BPF_F_FAST_STACK_CMP)
+		return id;
+
+	if (stack_map_use_build_id(map)) {
+		/* for build_id+offset, pop a bucket before slow cmp */
+		new_bucket = (struct stack_map_bucket *)
+			pcpu_freelist_pop(&smap->freelist);
+		if (unlikely(!new_bucket))
+			return -ENOMEM;
+		new_bucket->nr = trace_nr;
+		stack_map_get_build_id_offset(
+			(struct bpf_stack_build_id *)new_bucket->data,
+			ips, trace_nr, user);
+		trace_len = trace_nr * sizeof(struct bpf_stack_build_id);
+		if (hash_matches && bucket->nr == trace_nr &&
+		    memcmp(bucket->data, new_bucket->data, trace_len) == 0) {
+			pcpu_freelist_push(&smap->freelist, &new_bucket->fnode);
+			return id;
+		}
+		if (bucket && !(flags & BPF_F_REUSE_STACKID)) {
+			pcpu_freelist_push(&smap->freelist, &new_bucket->fnode);
+			return -EEXIST;
+		}
+	} else {
+		if (hash_matches && bucket->nr == trace_nr &&
+		    memcmp(bucket->data, ips, trace_len) == 0)
+			return id;
+		if (bucket && !(flags & BPF_F_REUSE_STACKID))
+			return -EEXIST;
+
+		new_bucket = (struct stack_map_bucket *)
+			pcpu_freelist_pop(&smap->freelist);
+		if (unlikely(!new_bucket))
+			return -ENOMEM;
+		memcpy(new_bucket->data, ips, trace_len);
+	}
+
+	new_bucket->hash = hash;
+	new_bucket->nr = trace_nr;
+
+	old_bucket = xchg(&smap->buckets[id], new_bucket);
+	if (old_bucket)
+		pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);
+	return id;
+}
+
+BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map,
+	   u64, flags)
+{
+	u32 max_depth = map->value_size / stack_map_data_size(map);
+	u32 skip = flags & BPF_F_SKIP_FIELD_MASK;
+	bool user = flags & BPF_F_USER_STACK;
+	struct perf_callchain_entry *trace;
+	bool kernel = !user;
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))
+		return -EINVAL;
+
+	max_depth += skip;
+	if (max_depth > sysctl_perf_event_max_stack)
+		max_depth = sysctl_perf_event_max_stack;
+
+	trace = get_perf_callchain(regs, 0, kernel, user, max_depth,
+				   false, false);
+
+	if (unlikely(!trace))
+		/* couldn't fetch the stack trace */
+		return -EFAULT;
+
+	return __bpf_get_stackid(map, trace, flags);
+}
+
+const struct bpf_func_proto bpf_get_stackid_proto = {
+	.func		= bpf_get_stackid,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_CONST_MAP_PTR,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+static __u64 count_kernel_ip(struct perf_callchain_entry *trace)
+{
+	__u64 nr_kernel = 0;
+
+	while (nr_kernel < trace->nr) {
+		if (trace->ip[nr_kernel] == PERF_CONTEXT_USER)
+			break;
+		nr_kernel++;
+	}
+	return nr_kernel;
+}
+
+BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx,
+	   struct bpf_map *, map, u64, flags)
+{
+	struct perf_event *event = ctx->event;
+	struct perf_callchain_entry *trace;
+	bool kernel, user;
+	__u64 nr_kernel;
+	int ret;
+
+	/* perf_sample_data doesn't have callchain, use bpf_get_stackid */
+	if (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY))
+		return bpf_get_stackid((unsigned long)(ctx->regs),
+				       (unsigned long) map, flags, 0, 0);
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))
+		return -EINVAL;
+
+	user = flags & BPF_F_USER_STACK;
+	kernel = !user;
+
+	trace = ctx->data->callchain;
+	if (unlikely(!trace))
+		return -EFAULT;
+
+	nr_kernel = count_kernel_ip(trace);
+
+	if (kernel) {
+		__u64 nr = trace->nr;
+
+		trace->nr = nr_kernel;
+		ret = __bpf_get_stackid(map, trace, flags);
+
+		/* restore nr */
+		trace->nr = nr;
+	} else { /* user */
+		u64 skip = flags & BPF_F_SKIP_FIELD_MASK;
+
+		skip += nr_kernel;
+		if (skip > BPF_F_SKIP_FIELD_MASK)
+			return -EFAULT;
+
+		flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip;
+		ret = __bpf_get_stackid(map, trace, flags);
+	}
+	return ret;
+}
+
+const struct bpf_func_proto bpf_get_stackid_proto_pe = {
+	.func		= bpf_get_stackid_pe,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_CONST_MAP_PTR,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task,
+			    struct perf_callchain_entry *trace_in,
+			    void *buf, u32 size, u64 flags)
+{
+	u32 trace_nr, copy_len, elem_size, num_elem, max_depth;
+	bool user_build_id = flags & BPF_F_USER_BUILD_ID;
+	bool crosstask = task && task != current;
+	u32 skip = flags & BPF_F_SKIP_FIELD_MASK;
+	bool user = flags & BPF_F_USER_STACK;
+	struct perf_callchain_entry *trace;
+	bool kernel = !user;
+	int err = -EINVAL;
+	u64 *ips;
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_USER_BUILD_ID)))
+		goto clear;
+	if (kernel && user_build_id)
+		goto clear;
+
+	elem_size = (user && user_build_id) ? sizeof(struct bpf_stack_build_id)
+					    : sizeof(u64);
+	if (unlikely(size % elem_size))
+		goto clear;
+
+	/* cannot get valid user stack for task without user_mode regs */
+	if (task && user && !user_mode(regs))
+		goto err_fault;
+
+	/* get_perf_callchain does not support crosstask user stack walking
+	 * but returns an empty stack instead of NULL.
+	 */
+	if (crosstask && user) {
+		err = -EOPNOTSUPP;
+		goto clear;
+	}
+
+	num_elem = size / elem_size;
+	max_depth = num_elem + skip;
+	if (sysctl_perf_event_max_stack < max_depth)
+		max_depth = sysctl_perf_event_max_stack;
+
+	if (trace_in)
+		trace = trace_in;
+	else if (kernel && task)
+		trace = get_callchain_entry_for_task(task, max_depth);
+	else
+		trace = get_perf_callchain(regs, 0, kernel, user, max_depth,
+					   crosstask, false);
+	if (unlikely(!trace))
+		goto err_fault;
+
+	if (trace->nr < skip)
+		goto err_fault;
+
+	trace_nr = trace->nr - skip;
+	trace_nr = (trace_nr <= num_elem) ? trace_nr : num_elem;
+	copy_len = trace_nr * elem_size;
+
+	ips = trace->ip + skip;
+	if (user && user_build_id)
+		stack_map_get_build_id_offset(buf, ips, trace_nr, user);
+	else
+		memcpy(buf, ips, copy_len);
+
+	if (size > copy_len)
+		memset(buf + copy_len, 0, size - copy_len);
+	return copy_len;
+
+err_fault:
+	err = -EFAULT;
+clear:
+	memset(buf, 0, size);
+	return err;
+}
+
+BPF_CALL_4(bpf_get_stack, struct pt_regs *, regs, void *, buf, u32, size,
+	   u64, flags)
+{
+	return __bpf_get_stack(regs, NULL, NULL, buf, size, flags);
+}
+
+const struct bpf_func_proto bpf_get_stack_proto = {
+	.func		= bpf_get_stack,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_4(bpf_get_task_stack, struct task_struct *, task, void *, buf,
+	   u32, size, u64, flags)
+{
+	struct pt_regs *regs;
+	long res = -EINVAL;
+
+	if (!try_get_task_stack(task))
+		return -EFAULT;
+
+	regs = task_pt_regs(task);
+	if (regs)
+		res = __bpf_get_stack(regs, task, NULL, buf, size, flags);
+	put_task_stack(task);
+
+	return res;
+}
+
+BTF_ID_LIST_SINGLE(bpf_get_task_stack_btf_ids, struct, task_struct)
+
+const struct bpf_func_proto bpf_get_task_stack_proto = {
+	.func		= bpf_get_task_stack,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &bpf_get_task_stack_btf_ids[0],
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data_kern *, ctx,
+	   void *, buf, u32, size, u64, flags)
+{
+	struct pt_regs *regs = (struct pt_regs *)(ctx->regs);
+	struct perf_event *event = ctx->event;
+	struct perf_callchain_entry *trace;
+	bool kernel, user;
+	int err = -EINVAL;
+	__u64 nr_kernel;
+
+	if (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY))
+		return __bpf_get_stack(regs, NULL, NULL, buf, size, flags);
+
+	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |
+			       BPF_F_USER_BUILD_ID)))
+		goto clear;
+
+	user = flags & BPF_F_USER_STACK;
+	kernel = !user;
+
+	err = -EFAULT;
+	trace = ctx->data->callchain;
+	if (unlikely(!trace))
+		goto clear;
+
+	nr_kernel = count_kernel_ip(trace);
+
+	if (kernel) {
+		__u64 nr = trace->nr;
+
+		trace->nr = nr_kernel;
+		err = __bpf_get_stack(regs, NULL, trace, buf, size, flags);
+
+		/* restore nr */
+		trace->nr = nr;
+	} else { /* user */
+		u64 skip = flags & BPF_F_SKIP_FIELD_MASK;
+
+		skip += nr_kernel;
+		if (skip > BPF_F_SKIP_FIELD_MASK)
+			goto clear;
+
+		flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip;
+		err = __bpf_get_stack(regs, NULL, trace, buf, size, flags);
+	}
+	return err;
+
+clear:
+	memset(buf, 0, size);
+	return err;
+
+}
+
+const struct bpf_func_proto bpf_get_stack_proto_pe = {
+	.func		= bpf_get_stack_pe,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
+	.arg4_type	= ARG_ANYTHING,
+};
+
+/* Called from eBPF program */
+static void *stack_map_lookup_elem(struct bpf_map *map, void *key)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+/* Called from syscall */
+int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
+{
+	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+	struct stack_map_bucket *bucket, *old_bucket;
+	u32 id = *(u32 *)key, trace_len;
+
+	if (unlikely(id >= smap->n_buckets))
+		return -ENOENT;
+
+	bucket = xchg(&smap->buckets[id], NULL);
+	if (!bucket)
+		return -ENOENT;
+
+	trace_len = bucket->nr * stack_map_data_size(map);
+	memcpy(value, bucket->data, trace_len);
+	memset(value + trace_len, 0, map->value_size - trace_len);
+
+	old_bucket = xchg(&smap->buckets[id], bucket);
+	if (old_bucket)
+		pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);
+	return 0;
+}
+
+static int stack_map_get_next_key(struct bpf_map *map, void *key,
+				  void *next_key)
+{
+	struct bpf_stack_map *smap = container_of(map,
+						  struct bpf_stack_map, map);
+	u32 id;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	if (!key) {
+		id = 0;
+	} else {
+		id = *(u32 *)key;
+		if (id >= smap->n_buckets || !smap->buckets[id])
+			id = 0;
+		else
+			id++;
+	}
+
+	while (id < smap->n_buckets && !smap->buckets[id])
+		id++;
+
+	if (id >= smap->n_buckets)
+		return -ENOENT;
+
+	*(u32 *)next_key = id;
+	return 0;
+}
+
+static int stack_map_update_elem(struct bpf_map *map, void *key, void *value,
+				 u64 map_flags)
+{
+	return -EINVAL;
+}
+
+/* Called from syscall or from eBPF program */
+static int stack_map_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+	struct stack_map_bucket *old_bucket;
+	u32 id = *(u32 *)key;
+
+	if (unlikely(id >= smap->n_buckets))
+		return -E2BIG;
+
+	old_bucket = xchg(&smap->buckets[id], NULL);
+	if (old_bucket) {
+		pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);
+		return 0;
+	} else {
+		return -ENOENT;
+	}
+}
+
+/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
+static void stack_map_free(struct bpf_map *map)
+{
+	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);
+
+	bpf_map_area_free(smap->elems);
+	pcpu_freelist_destroy(&smap->freelist);
+	bpf_map_area_free(smap);
+	put_callchain_buffers();
+}
+
+static int stack_trace_map_btf_id;
+const struct bpf_map_ops stack_trace_map_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc = stack_map_alloc,
+	.map_free = stack_map_free,
+	.map_get_next_key = stack_map_get_next_key,
+	.map_lookup_elem = stack_map_lookup_elem,
+	.map_update_elem = stack_map_update_elem,
+	.map_delete_elem = stack_map_delete_elem,
+	.map_check_btf = map_check_no_btf,
+	.map_btf_name = "bpf_stack_map",
+	.map_btf_id = &stack_trace_map_btf_id,
+};
+
+static int __init stack_map_init(void)
+{
+	int cpu;
+	struct stack_map_irq_work *work;
+
+	for_each_possible_cpu(cpu) {
+		work = per_cpu_ptr(&up_read_work, cpu);
+		init_irq_work(&work->irq_work, do_up_read);
+	}
+	return 0;
+}
+subsys_initcall(stack_map_init);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
new file mode 100644
index 000000000..aaad2dce2
--- /dev/null
+++ b/kernel/bpf/syscall.c
@@ -0,0 +1,4525 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ */
+#include <linux/bpf.h>
+#include <linux/bpf_trace.h>
+#include <linux/bpf_lirc.h>
+#include <linux/bpf_verifier.h>
+#include <linux/btf.h>
+#include <linux/syscalls.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/vmalloc.h>
+#include <linux/mmzone.h>
+#include <linux/anon_inodes.h>
+#include <linux/fdtable.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/license.h>
+#include <linux/filter.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/idr.h>
+#include <linux/cred.h>
+#include <linux/timekeeping.h>
+#include <linux/ctype.h>
+#include <linux/nospec.h>
+#include <linux/audit.h>
+#include <uapi/linux/btf.h>
+#include <linux/pgtable.h>
+#include <linux/bpf_lsm.h>
+#include <linux/poll.h>
+#include <linux/bpf-netns.h>
+#include <linux/rcupdate_trace.h>
+
+#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
+			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
+			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
+#define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
+#define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
+#define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
+			IS_FD_HASH(map))
+
+#define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
+
+DEFINE_PER_CPU(int, bpf_prog_active);
+static DEFINE_IDR(prog_idr);
+static DEFINE_SPINLOCK(prog_idr_lock);
+static DEFINE_IDR(map_idr);
+static DEFINE_SPINLOCK(map_idr_lock);
+static DEFINE_IDR(link_idr);
+static DEFINE_SPINLOCK(link_idr_lock);
+
+int sysctl_unprivileged_bpf_disabled __read_mostly =
+	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
+
+static const struct bpf_map_ops * const bpf_map_types[] = {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
+#define BPF_MAP_TYPE(_id, _ops) \
+	[_id] = &_ops,
+#define BPF_LINK_TYPE(_id, _name)
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+#undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
+};
+
+/*
+ * If we're handed a bigger struct than we know of, ensure all the unknown bits
+ * are 0 - i.e. new user-space does not rely on any kernel feature extensions
+ * we don't know about yet.
+ *
+ * There is a ToCToU between this function call and the following
+ * copy_from_user() call. However, this is not a concern since this function is
+ * meant to be a future-proofing of bits.
+ */
+int bpf_check_uarg_tail_zero(void __user *uaddr,
+			     size_t expected_size,
+			     size_t actual_size)
+{
+	unsigned char __user *addr = uaddr + expected_size;
+	int res;
+
+	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
+		return -E2BIG;
+
+	if (actual_size <= expected_size)
+		return 0;
+
+	res = check_zeroed_user(addr, actual_size - expected_size);
+	if (res < 0)
+		return res;
+	return res ? 0 : -E2BIG;
+}
+
+const struct bpf_map_ops bpf_map_offload_ops = {
+	.map_meta_equal = bpf_map_meta_equal,
+	.map_alloc = bpf_map_offload_map_alloc,
+	.map_free = bpf_map_offload_map_free,
+	.map_check_btf = map_check_no_btf,
+};
+
+static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
+{
+	const struct bpf_map_ops *ops;
+	u32 type = attr->map_type;
+	struct bpf_map *map;
+	int err;
+
+	if (type >= ARRAY_SIZE(bpf_map_types))
+		return ERR_PTR(-EINVAL);
+	type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
+	ops = bpf_map_types[type];
+	if (!ops)
+		return ERR_PTR(-EINVAL);
+
+	if (ops->map_alloc_check) {
+		err = ops->map_alloc_check(attr);
+		if (err)
+			return ERR_PTR(err);
+	}
+	if (attr->map_ifindex)
+		ops = &bpf_map_offload_ops;
+	map = ops->map_alloc(attr);
+	if (IS_ERR(map))
+		return map;
+	map->ops = ops;
+	map->map_type = type;
+	return map;
+}
+
+static void bpf_map_write_active_inc(struct bpf_map *map)
+{
+	atomic64_inc(&map->writecnt);
+}
+
+static void bpf_map_write_active_dec(struct bpf_map *map)
+{
+	atomic64_dec(&map->writecnt);
+}
+
+bool bpf_map_write_active(const struct bpf_map *map)
+{
+	return atomic64_read(&map->writecnt) != 0;
+}
+
+static u32 bpf_map_value_size(struct bpf_map *map)
+{
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
+		return round_up(map->value_size, 8) * num_possible_cpus();
+	else if (IS_FD_MAP(map))
+		return sizeof(u32);
+	else
+		return  map->value_size;
+}
+
+static void maybe_wait_bpf_programs(struct bpf_map *map)
+{
+	/* Wait for any running BPF programs to complete so that
+	 * userspace, when we return to it, knows that all programs
+	 * that could be running use the new map value.
+	 */
+	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
+	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
+		synchronize_rcu();
+}
+
+static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
+				void *value, __u64 flags)
+{
+	int err;
+
+	/* Need to create a kthread, thus must support schedule */
+	if (bpf_map_is_dev_bound(map)) {
+		return bpf_map_offload_update_elem(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
+		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		return map->ops->map_update_elem(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
+		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
+		return sock_map_update_elem_sys(map, key, value, flags);
+	} else if (IS_FD_PROG_ARRAY(map)) {
+		return bpf_fd_array_map_update_elem(map, f.file, key, value,
+						    flags);
+	}
+
+	bpf_disable_instrumentation();
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+		err = bpf_percpu_hash_update(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		err = bpf_percpu_array_update(map, key, value, flags);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
+		err = bpf_percpu_cgroup_storage_update(map, key, value,
+						       flags);
+	} else if (IS_FD_ARRAY(map)) {
+		rcu_read_lock();
+		err = bpf_fd_array_map_update_elem(map, f.file, key, value,
+						   flags);
+		rcu_read_unlock();
+	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
+		rcu_read_lock();
+		err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
+						  flags);
+		rcu_read_unlock();
+	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
+		/* rcu_read_lock() is not needed */
+		err = bpf_fd_reuseport_array_update_elem(map, key, value,
+							 flags);
+	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
+		   map->map_type == BPF_MAP_TYPE_STACK) {
+		err = map->ops->map_push_elem(map, value, flags);
+	} else {
+		rcu_read_lock();
+		err = map->ops->map_update_elem(map, key, value, flags);
+		rcu_read_unlock();
+	}
+	bpf_enable_instrumentation();
+	maybe_wait_bpf_programs(map);
+
+	return err;
+}
+
+static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
+			      __u64 flags)
+{
+	void *ptr;
+	int err;
+
+	if (bpf_map_is_dev_bound(map))
+		return bpf_map_offload_lookup_elem(map, key, value);
+
+	bpf_disable_instrumentation();
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+		err = bpf_percpu_hash_copy(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+		err = bpf_percpu_array_copy(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
+		err = bpf_percpu_cgroup_storage_copy(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
+		err = bpf_stackmap_copy(map, key, value);
+	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
+		err = bpf_fd_array_map_lookup_elem(map, key, value);
+	} else if (IS_FD_HASH(map)) {
+		err = bpf_fd_htab_map_lookup_elem(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
+		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
+		   map->map_type == BPF_MAP_TYPE_STACK) {
+		err = map->ops->map_peek_elem(map, value);
+	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		/* struct_ops map requires directly updating "value" */
+		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
+	} else {
+		rcu_read_lock();
+		if (map->ops->map_lookup_elem_sys_only)
+			ptr = map->ops->map_lookup_elem_sys_only(map, key);
+		else
+			ptr = map->ops->map_lookup_elem(map, key);
+		if (IS_ERR(ptr)) {
+			err = PTR_ERR(ptr);
+		} else if (!ptr) {
+			err = -ENOENT;
+		} else {
+			err = 0;
+			if (flags & BPF_F_LOCK)
+				/* lock 'ptr' and copy everything but lock */
+				copy_map_value_locked(map, value, ptr, true);
+			else
+				copy_map_value(map, value, ptr);
+			/* mask lock, since value wasn't zero inited */
+			check_and_init_map_lock(map, value);
+		}
+		rcu_read_unlock();
+	}
+
+	bpf_enable_instrumentation();
+	maybe_wait_bpf_programs(map);
+
+	return err;
+}
+
+static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
+{
+	/* We really just want to fail instead of triggering OOM killer
+	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
+	 * which is used for lower order allocation requests.
+	 *
+	 * It has been observed that higher order allocation requests done by
+	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
+	 * to reclaim memory from the page cache, thus we set
+	 * __GFP_RETRY_MAYFAIL to avoid such situations.
+	 */
+
+	const gfp_t gfp = __GFP_NOWARN | __GFP_ZERO;
+	unsigned int flags = 0;
+	unsigned long align = 1;
+	void *area;
+
+	if (size >= SIZE_MAX)
+		return NULL;
+
+	/* kmalloc()'ed memory can't be mmap()'ed */
+	if (mmapable) {
+		BUG_ON(!PAGE_ALIGNED(size));
+		align = SHMLBA;
+		flags = VM_USERMAP;
+	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
+		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
+				    numa_node);
+		if (area != NULL)
+			return area;
+	}
+
+	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
+			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
+			flags, numa_node, __builtin_return_address(0));
+}
+
+void *bpf_map_area_alloc(u64 size, int numa_node)
+{
+	return __bpf_map_area_alloc(size, numa_node, false);
+}
+
+void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
+{
+	return __bpf_map_area_alloc(size, numa_node, true);
+}
+
+void bpf_map_area_free(void *area)
+{
+	kvfree(area);
+}
+
+static u32 bpf_map_flags_retain_permanent(u32 flags)
+{
+	/* Some map creation flags are not tied to the map object but
+	 * rather to the map fd instead, so they have no meaning upon
+	 * map object inspection since multiple file descriptors with
+	 * different (access) properties can exist here. Thus, given
+	 * this has zero meaning for the map itself, lets clear these
+	 * from here.
+	 */
+	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
+}
+
+void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
+{
+	map->map_type = attr->map_type;
+	map->key_size = attr->key_size;
+	map->value_size = attr->value_size;
+	map->max_entries = attr->max_entries;
+	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
+	map->numa_node = bpf_map_attr_numa_node(attr);
+}
+
+static int bpf_charge_memlock(struct user_struct *user, u32 pages)
+{
+	unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+
+	if (atomic_long_add_return(pages, &user->locked_vm) > memlock_limit) {
+		atomic_long_sub(pages, &user->locked_vm);
+		return -EPERM;
+	}
+	return 0;
+}
+
+static void bpf_uncharge_memlock(struct user_struct *user, u32 pages)
+{
+	if (user)
+		atomic_long_sub(pages, &user->locked_vm);
+}
+
+int bpf_map_charge_init(struct bpf_map_memory *mem, u64 size)
+{
+	u32 pages = round_up(size, PAGE_SIZE) >> PAGE_SHIFT;
+	struct user_struct *user;
+	int ret;
+
+	if (size >= U32_MAX - PAGE_SIZE)
+		return -E2BIG;
+
+	user = get_current_user();
+	ret = bpf_charge_memlock(user, pages);
+	if (ret) {
+		free_uid(user);
+		return ret;
+	}
+
+	mem->pages = pages;
+	mem->user = user;
+
+	return 0;
+}
+
+void bpf_map_charge_finish(struct bpf_map_memory *mem)
+{
+	bpf_uncharge_memlock(mem->user, mem->pages);
+	free_uid(mem->user);
+}
+
+void bpf_map_charge_move(struct bpf_map_memory *dst,
+			 struct bpf_map_memory *src)
+{
+	*dst = *src;
+
+	/* Make sure src will not be used for the redundant uncharging. */
+	memset(src, 0, sizeof(struct bpf_map_memory));
+}
+
+int bpf_map_charge_memlock(struct bpf_map *map, u32 pages)
+{
+	int ret;
+
+	ret = bpf_charge_memlock(map->memory.user, pages);
+	if (ret)
+		return ret;
+	map->memory.pages += pages;
+	return ret;
+}
+
+void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages)
+{
+	bpf_uncharge_memlock(map->memory.user, pages);
+	map->memory.pages -= pages;
+}
+
+static int bpf_map_alloc_id(struct bpf_map *map)
+{
+	int id;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock_bh(&map_idr_lock);
+	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
+	if (id > 0)
+		map->id = id;
+	spin_unlock_bh(&map_idr_lock);
+	idr_preload_end();
+
+	if (WARN_ON_ONCE(!id))
+		return -ENOSPC;
+
+	return id > 0 ? 0 : id;
+}
+
+void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
+{
+	unsigned long flags;
+
+	/* Offloaded maps are removed from the IDR store when their device
+	 * disappears - even if someone holds an fd to them they are unusable,
+	 * the memory is gone, all ops will fail; they are simply waiting for
+	 * refcnt to drop to be freed.
+	 */
+	if (!map->id)
+		return;
+
+	if (do_idr_lock)
+		spin_lock_irqsave(&map_idr_lock, flags);
+	else
+		__acquire(&map_idr_lock);
+
+	idr_remove(&map_idr, map->id);
+	map->id = 0;
+
+	if (do_idr_lock)
+		spin_unlock_irqrestore(&map_idr_lock, flags);
+	else
+		__release(&map_idr_lock);
+}
+
+/* called from workqueue */
+static void bpf_map_free_deferred(struct work_struct *work)
+{
+	struct bpf_map *map = container_of(work, struct bpf_map, work);
+	struct bpf_map_memory mem;
+
+	bpf_map_charge_move(&mem, &map->memory);
+	security_bpf_map_free(map);
+	/* implementation dependent freeing */
+	map->ops->map_free(map);
+	bpf_map_charge_finish(&mem);
+}
+
+static void bpf_map_put_uref(struct bpf_map *map)
+{
+	if (atomic64_dec_and_test(&map->usercnt)) {
+		if (map->ops->map_release_uref)
+			map->ops->map_release_uref(map);
+	}
+}
+
+/* decrement map refcnt and schedule it for freeing via workqueue
+ * (unrelying map implementation ops->map_free() might sleep)
+ */
+static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
+{
+	if (atomic64_dec_and_test(&map->refcnt)) {
+		/* bpf_map_free_id() must be called first */
+		bpf_map_free_id(map, do_idr_lock);
+		btf_put(map->btf);
+		INIT_WORK(&map->work, bpf_map_free_deferred);
+		schedule_work(&map->work);
+	}
+}
+
+void bpf_map_put(struct bpf_map *map)
+{
+	__bpf_map_put(map, true);
+}
+EXPORT_SYMBOL_GPL(bpf_map_put);
+
+void bpf_map_put_with_uref(struct bpf_map *map)
+{
+	bpf_map_put_uref(map);
+	bpf_map_put(map);
+}
+
+static int bpf_map_release(struct inode *inode, struct file *filp)
+{
+	struct bpf_map *map = filp->private_data;
+
+	if (map->ops->map_release)
+		map->ops->map_release(map, filp);
+
+	bpf_map_put_with_uref(map);
+	return 0;
+}
+
+static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
+{
+	fmode_t mode = f.file->f_mode;
+
+	/* Our file permissions may have been overridden by global
+	 * map permissions facing syscall side.
+	 */
+	if (READ_ONCE(map->frozen))
+		mode &= ~FMODE_CAN_WRITE;
+	return mode;
+}
+
+#ifdef CONFIG_PROC_FS
+static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
+{
+	const struct bpf_map *map = filp->private_data;
+	const struct bpf_array *array;
+	u32 type = 0, jited = 0;
+
+	if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
+		array = container_of(map, struct bpf_array, map);
+		spin_lock(&array->aux->owner.lock);
+		type  = array->aux->owner.type;
+		jited = array->aux->owner.jited;
+		spin_unlock(&array->aux->owner.lock);
+	}
+
+	seq_printf(m,
+		   "map_type:\t%u\n"
+		   "key_size:\t%u\n"
+		   "value_size:\t%u\n"
+		   "max_entries:\t%u\n"
+		   "map_flags:\t%#x\n"
+		   "memlock:\t%llu\n"
+		   "map_id:\t%u\n"
+		   "frozen:\t%u\n",
+		   map->map_type,
+		   map->key_size,
+		   map->value_size,
+		   map->max_entries,
+		   map->map_flags,
+		   map->memory.pages * 1ULL << PAGE_SHIFT,
+		   map->id,
+		   READ_ONCE(map->frozen));
+	if (type) {
+		seq_printf(m, "owner_prog_type:\t%u\n", type);
+		seq_printf(m, "owner_jited:\t%u\n", jited);
+	}
+}
+#endif
+
+static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
+			      loff_t *ppos)
+{
+	/* We need this handler such that alloc_file() enables
+	 * f_mode with FMODE_CAN_READ.
+	 */
+	return -EINVAL;
+}
+
+static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
+			       size_t siz, loff_t *ppos)
+{
+	/* We need this handler such that alloc_file() enables
+	 * f_mode with FMODE_CAN_WRITE.
+	 */
+	return -EINVAL;
+}
+
+/* called for any extra memory-mapped regions (except initial) */
+static void bpf_map_mmap_open(struct vm_area_struct *vma)
+{
+	struct bpf_map *map = vma->vm_file->private_data;
+
+	if (vma->vm_flags & VM_MAYWRITE)
+		bpf_map_write_active_inc(map);
+}
+
+/* called for all unmapped memory region (including initial) */
+static void bpf_map_mmap_close(struct vm_area_struct *vma)
+{
+	struct bpf_map *map = vma->vm_file->private_data;
+
+	if (vma->vm_flags & VM_MAYWRITE)
+		bpf_map_write_active_dec(map);
+}
+
+static const struct vm_operations_struct bpf_map_default_vmops = {
+	.open		= bpf_map_mmap_open,
+	.close		= bpf_map_mmap_close,
+};
+
+static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct bpf_map *map = filp->private_data;
+	int err;
+
+	if (!map->ops->map_mmap || map_value_has_spin_lock(map))
+		return -ENOTSUPP;
+
+	if (!(vma->vm_flags & VM_SHARED))
+		return -EINVAL;
+
+	mutex_lock(&map->freeze_mutex);
+
+	if (vma->vm_flags & VM_WRITE) {
+		if (map->frozen) {
+			err = -EPERM;
+			goto out;
+		}
+		/* map is meant to be read-only, so do not allow mapping as
+		 * writable, because it's possible to leak a writable page
+		 * reference and allows user-space to still modify it after
+		 * freezing, while verifier will assume contents do not change
+		 */
+		if (map->map_flags & BPF_F_RDONLY_PROG) {
+			err = -EACCES;
+			goto out;
+		}
+	}
+
+	/* set default open/close callbacks */
+	vma->vm_ops = &bpf_map_default_vmops;
+	vma->vm_private_data = map;
+	vma->vm_flags &= ~VM_MAYEXEC;
+	if (!(vma->vm_flags & VM_WRITE))
+		/* disallow re-mapping with PROT_WRITE */
+		vma->vm_flags &= ~VM_MAYWRITE;
+
+	err = map->ops->map_mmap(map, vma);
+	if (err)
+		goto out;
+
+	if (vma->vm_flags & VM_MAYWRITE)
+		bpf_map_write_active_inc(map);
+out:
+	mutex_unlock(&map->freeze_mutex);
+	return err;
+}
+
+static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
+{
+	struct bpf_map *map = filp->private_data;
+
+	if (map->ops->map_poll)
+		return map->ops->map_poll(map, filp, pts);
+
+	return EPOLLERR;
+}
+
+const struct file_operations bpf_map_fops = {
+#ifdef CONFIG_PROC_FS
+	.show_fdinfo	= bpf_map_show_fdinfo,
+#endif
+	.release	= bpf_map_release,
+	.read		= bpf_dummy_read,
+	.write		= bpf_dummy_write,
+	.mmap		= bpf_map_mmap,
+	.poll		= bpf_map_poll,
+};
+
+int bpf_map_new_fd(struct bpf_map *map, int flags)
+{
+	int ret;
+
+	ret = security_bpf_map(map, OPEN_FMODE(flags));
+	if (ret < 0)
+		return ret;
+
+	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
+				flags | O_CLOEXEC);
+}
+
+int bpf_get_file_flag(int flags)
+{
+	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
+		return -EINVAL;
+	if (flags & BPF_F_RDONLY)
+		return O_RDONLY;
+	if (flags & BPF_F_WRONLY)
+		return O_WRONLY;
+	return O_RDWR;
+}
+
+/* helper macro to check that unused fields 'union bpf_attr' are zero */
+#define CHECK_ATTR(CMD) \
+	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
+		   sizeof(attr->CMD##_LAST_FIELD), 0, \
+		   sizeof(*attr) - \
+		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
+		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
+
+/* dst and src must have at least "size" number of bytes.
+ * Return strlen on success and < 0 on error.
+ */
+int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
+{
+	const char *end = src + size;
+	const char *orig_src = src;
+
+	memset(dst, 0, size);
+	/* Copy all isalnum(), '_' and '.' chars. */
+	while (src < end && *src) {
+		if (!isalnum(*src) &&
+		    *src != '_' && *src != '.')
+			return -EINVAL;
+		*dst++ = *src++;
+	}
+
+	/* No '\0' found in "size" number of bytes */
+	if (src == end)
+		return -EINVAL;
+
+	return src - orig_src;
+}
+
+int map_check_no_btf(const struct bpf_map *map,
+		     const struct btf *btf,
+		     const struct btf_type *key_type,
+		     const struct btf_type *value_type)
+{
+	return -ENOTSUPP;
+}
+
+static int map_check_btf(struct bpf_map *map, const struct btf *btf,
+			 u32 btf_key_id, u32 btf_value_id)
+{
+	const struct btf_type *key_type, *value_type;
+	u32 key_size, value_size;
+	int ret = 0;
+
+	/* Some maps allow key to be unspecified. */
+	if (btf_key_id) {
+		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
+		if (!key_type || key_size != map->key_size)
+			return -EINVAL;
+	} else {
+		key_type = btf_type_by_id(btf, 0);
+		if (!map->ops->map_check_btf)
+			return -EINVAL;
+	}
+
+	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
+	if (!value_type || value_size != map->value_size)
+		return -EINVAL;
+
+	map->spin_lock_off = btf_find_spin_lock(btf, value_type);
+
+	if (map_value_has_spin_lock(map)) {
+		if (map->map_flags & BPF_F_RDONLY_PROG)
+			return -EACCES;
+		if (map->map_type != BPF_MAP_TYPE_HASH &&
+		    map->map_type != BPF_MAP_TYPE_ARRAY &&
+		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
+		    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
+		    map->map_type != BPF_MAP_TYPE_INODE_STORAGE)
+			return -ENOTSUPP;
+		if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
+		    map->value_size) {
+			WARN_ONCE(1,
+				  "verifier bug spin_lock_off %d value_size %d\n",
+				  map->spin_lock_off, map->value_size);
+			return -EFAULT;
+		}
+	}
+
+	if (map->ops->map_check_btf)
+		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
+
+	return ret;
+}
+
+#define BPF_MAP_CREATE_LAST_FIELD btf_vmlinux_value_type_id
+/* called via syscall */
+static int map_create(union bpf_attr *attr)
+{
+	int numa_node = bpf_map_attr_numa_node(attr);
+	struct bpf_map_memory mem;
+	struct bpf_map *map;
+	int f_flags;
+	int err;
+
+	err = CHECK_ATTR(BPF_MAP_CREATE);
+	if (err)
+		return -EINVAL;
+
+	if (attr->btf_vmlinux_value_type_id) {
+		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
+		    attr->btf_key_type_id || attr->btf_value_type_id)
+			return -EINVAL;
+	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
+		return -EINVAL;
+	}
+
+	f_flags = bpf_get_file_flag(attr->map_flags);
+	if (f_flags < 0)
+		return f_flags;
+
+	if (numa_node != NUMA_NO_NODE &&
+	    ((unsigned int)numa_node >= nr_node_ids ||
+	     !node_online(numa_node)))
+		return -EINVAL;
+
+	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
+	map = find_and_alloc_map(attr);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	err = bpf_obj_name_cpy(map->name, attr->map_name,
+			       sizeof(attr->map_name));
+	if (err < 0)
+		goto free_map;
+
+	atomic64_set(&map->refcnt, 1);
+	atomic64_set(&map->usercnt, 1);
+	mutex_init(&map->freeze_mutex);
+
+	map->spin_lock_off = -EINVAL;
+	if (attr->btf_key_type_id || attr->btf_value_type_id ||
+	    /* Even the map's value is a kernel's struct,
+	     * the bpf_prog.o must have BTF to begin with
+	     * to figure out the corresponding kernel's
+	     * counter part.  Thus, attr->btf_fd has
+	     * to be valid also.
+	     */
+	    attr->btf_vmlinux_value_type_id) {
+		struct btf *btf;
+
+		btf = btf_get_by_fd(attr->btf_fd);
+		if (IS_ERR(btf)) {
+			err = PTR_ERR(btf);
+			goto free_map;
+		}
+		map->btf = btf;
+
+		if (attr->btf_value_type_id) {
+			err = map_check_btf(map, btf, attr->btf_key_type_id,
+					    attr->btf_value_type_id);
+			if (err)
+				goto free_map;
+		}
+
+		map->btf_key_type_id = attr->btf_key_type_id;
+		map->btf_value_type_id = attr->btf_value_type_id;
+		map->btf_vmlinux_value_type_id =
+			attr->btf_vmlinux_value_type_id;
+	}
+
+	err = security_bpf_map_alloc(map);
+	if (err)
+		goto free_map;
+
+	err = bpf_map_alloc_id(map);
+	if (err)
+		goto free_map_sec;
+
+	err = bpf_map_new_fd(map, f_flags);
+	if (err < 0) {
+		/* failed to allocate fd.
+		 * bpf_map_put_with_uref() is needed because the above
+		 * bpf_map_alloc_id() has published the map
+		 * to the userspace and the userspace may
+		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
+		 */
+		bpf_map_put_with_uref(map);
+		return err;
+	}
+
+	return err;
+
+free_map_sec:
+	security_bpf_map_free(map);
+free_map:
+	btf_put(map->btf);
+	bpf_map_charge_move(&mem, &map->memory);
+	map->ops->map_free(map);
+	bpf_map_charge_finish(&mem);
+	return err;
+}
+
+/* if error is returned, fd is released.
+ * On success caller should complete fd access with matching fdput()
+ */
+struct bpf_map *__bpf_map_get(struct fd f)
+{
+	if (!f.file)
+		return ERR_PTR(-EBADF);
+	if (f.file->f_op != &bpf_map_fops) {
+		fdput(f);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return f.file->private_data;
+}
+
+void bpf_map_inc(struct bpf_map *map)
+{
+	atomic64_inc(&map->refcnt);
+}
+EXPORT_SYMBOL_GPL(bpf_map_inc);
+
+void bpf_map_inc_with_uref(struct bpf_map *map)
+{
+	atomic64_inc(&map->refcnt);
+	atomic64_inc(&map->usercnt);
+}
+EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
+
+struct bpf_map *bpf_map_get(u32 ufd)
+{
+	struct fd f = fdget(ufd);
+	struct bpf_map *map;
+
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return map;
+
+	bpf_map_inc(map);
+	fdput(f);
+
+	return map;
+}
+
+struct bpf_map *bpf_map_get_with_uref(u32 ufd)
+{
+	struct fd f = fdget(ufd);
+	struct bpf_map *map;
+
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return map;
+
+	bpf_map_inc_with_uref(map);
+	fdput(f);
+
+	return map;
+}
+
+/* map_idr_lock should have been held */
+static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
+{
+	int refold;
+
+	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
+	if (!refold)
+		return ERR_PTR(-ENOENT);
+	if (uref)
+		atomic64_inc(&map->usercnt);
+
+	return map;
+}
+
+struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
+{
+	spin_lock_bh(&map_idr_lock);
+	map = __bpf_map_inc_not_zero(map, false);
+	spin_unlock_bh(&map_idr_lock);
+
+	return map;
+}
+EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
+
+int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
+{
+	return -ENOTSUPP;
+}
+
+static void *__bpf_copy_key(void __user *ukey, u64 key_size)
+{
+	if (key_size)
+		return memdup_user(ukey, key_size);
+
+	if (ukey)
+		return ERR_PTR(-EINVAL);
+
+	return NULL;
+}
+
+/* last field in 'union bpf_attr' used by this command */
+#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
+
+static int map_lookup_elem(union bpf_attr *attr)
+{
+	void __user *ukey = u64_to_user_ptr(attr->key);
+	void __user *uvalue = u64_to_user_ptr(attr->value);
+	int ufd = attr->map_fd;
+	struct bpf_map *map;
+	void *key, *value;
+	u32 value_size;
+	struct fd f;
+	int err;
+
+	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
+		return -EINVAL;
+
+	if (attr->flags & ~BPF_F_LOCK)
+		return -EINVAL;
+
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	if ((attr->flags & BPF_F_LOCK) &&
+	    !map_value_has_spin_lock(map)) {
+		err = -EINVAL;
+		goto err_put;
+	}
+
+	key = __bpf_copy_key(ukey, map->key_size);
+	if (IS_ERR(key)) {
+		err = PTR_ERR(key);
+		goto err_put;
+	}
+
+	value_size = bpf_map_value_size(map);
+
+	err = -ENOMEM;
+	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
+	if (!value)
+		goto free_key;
+
+	err = bpf_map_copy_value(map, key, value, attr->flags);
+	if (err)
+		goto free_value;
+
+	err = -EFAULT;
+	if (copy_to_user(uvalue, value, value_size) != 0)
+		goto free_value;
+
+	err = 0;
+
+free_value:
+	kfree(value);
+free_key:
+	kfree(key);
+err_put:
+	fdput(f);
+	return err;
+}
+
+
+#define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
+
+static int map_update_elem(union bpf_attr *attr)
+{
+	void __user *ukey = u64_to_user_ptr(attr->key);
+	void __user *uvalue = u64_to_user_ptr(attr->value);
+	int ufd = attr->map_fd;
+	struct bpf_map *map;
+	void *key, *value;
+	u32 value_size;
+	struct fd f;
+	int err;
+
+	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
+		return -EINVAL;
+
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+	bpf_map_write_active_inc(map);
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	if ((attr->flags & BPF_F_LOCK) &&
+	    !map_value_has_spin_lock(map)) {
+		err = -EINVAL;
+		goto err_put;
+	}
+
+	key = __bpf_copy_key(ukey, map->key_size);
+	if (IS_ERR(key)) {
+		err = PTR_ERR(key);
+		goto err_put;
+	}
+
+	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
+	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
+		value_size = round_up(map->value_size, 8) * num_possible_cpus();
+	else
+		value_size = map->value_size;
+
+	err = -ENOMEM;
+	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
+	if (!value)
+		goto free_key;
+
+	err = -EFAULT;
+	if (copy_from_user(value, uvalue, value_size) != 0)
+		goto free_value;
+
+	err = bpf_map_update_value(map, f, key, value, attr->flags);
+
+free_value:
+	kfree(value);
+free_key:
+	kfree(key);
+err_put:
+	bpf_map_write_active_dec(map);
+	fdput(f);
+	return err;
+}
+
+#define BPF_MAP_DELETE_ELEM_LAST_FIELD key
+
+static int map_delete_elem(union bpf_attr *attr)
+{
+	void __user *ukey = u64_to_user_ptr(attr->key);
+	int ufd = attr->map_fd;
+	struct bpf_map *map;
+	struct fd f;
+	void *key;
+	int err;
+
+	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
+		return -EINVAL;
+
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+	bpf_map_write_active_inc(map);
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	key = __bpf_copy_key(ukey, map->key_size);
+	if (IS_ERR(key)) {
+		err = PTR_ERR(key);
+		goto err_put;
+	}
+
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_delete_elem(map, key);
+		goto out;
+	} else if (IS_FD_PROG_ARRAY(map) ||
+		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		/* These maps require sleepable context */
+		err = map->ops->map_delete_elem(map, key);
+		goto out;
+	}
+
+	bpf_disable_instrumentation();
+	rcu_read_lock();
+	err = map->ops->map_delete_elem(map, key);
+	rcu_read_unlock();
+	bpf_enable_instrumentation();
+	maybe_wait_bpf_programs(map);
+out:
+	kfree(key);
+err_put:
+	bpf_map_write_active_dec(map);
+	fdput(f);
+	return err;
+}
+
+/* last field in 'union bpf_attr' used by this command */
+#define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
+
+static int map_get_next_key(union bpf_attr *attr)
+{
+	void __user *ukey = u64_to_user_ptr(attr->key);
+	void __user *unext_key = u64_to_user_ptr(attr->next_key);
+	int ufd = attr->map_fd;
+	struct bpf_map *map;
+	void *key, *next_key;
+	struct fd f;
+	int err;
+
+	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
+		return -EINVAL;
+
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	if (ukey) {
+		key = __bpf_copy_key(ukey, map->key_size);
+		if (IS_ERR(key)) {
+			err = PTR_ERR(key);
+			goto err_put;
+		}
+	} else {
+		key = NULL;
+	}
+
+	err = -ENOMEM;
+	next_key = kmalloc(map->key_size, GFP_USER);
+	if (!next_key)
+		goto free_key;
+
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_get_next_key(map, key, next_key);
+		goto out;
+	}
+
+	rcu_read_lock();
+	err = map->ops->map_get_next_key(map, key, next_key);
+	rcu_read_unlock();
+out:
+	if (err)
+		goto free_next_key;
+
+	err = -EFAULT;
+	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
+		goto free_next_key;
+
+	err = 0;
+
+free_next_key:
+	kfree(next_key);
+free_key:
+	kfree(key);
+err_put:
+	fdput(f);
+	return err;
+}
+
+int generic_map_delete_batch(struct bpf_map *map,
+			     const union bpf_attr *attr,
+			     union bpf_attr __user *uattr)
+{
+	void __user *keys = u64_to_user_ptr(attr->batch.keys);
+	u32 cp, max_count;
+	int err = 0;
+	void *key;
+
+	if (attr->batch.elem_flags & ~BPF_F_LOCK)
+		return -EINVAL;
+
+	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
+	    !map_value_has_spin_lock(map)) {
+		return -EINVAL;
+	}
+
+	max_count = attr->batch.count;
+	if (!max_count)
+		return 0;
+
+	key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
+	if (!key)
+		return -ENOMEM;
+
+	for (cp = 0; cp < max_count; cp++) {
+		err = -EFAULT;
+		if (copy_from_user(key, keys + cp * map->key_size,
+				   map->key_size))
+			break;
+
+		if (bpf_map_is_dev_bound(map)) {
+			err = bpf_map_offload_delete_elem(map, key);
+			break;
+		}
+
+		bpf_disable_instrumentation();
+		rcu_read_lock();
+		err = map->ops->map_delete_elem(map, key);
+		rcu_read_unlock();
+		bpf_enable_instrumentation();
+		maybe_wait_bpf_programs(map);
+		if (err)
+			break;
+		cond_resched();
+	}
+	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
+		err = -EFAULT;
+
+	kfree(key);
+	return err;
+}
+
+int generic_map_update_batch(struct bpf_map *map,
+			     const union bpf_attr *attr,
+			     union bpf_attr __user *uattr)
+{
+	void __user *values = u64_to_user_ptr(attr->batch.values);
+	void __user *keys = u64_to_user_ptr(attr->batch.keys);
+	u32 value_size, cp, max_count;
+	int ufd = attr->batch.map_fd;
+	void *key, *value;
+	struct fd f;
+	int err = 0;
+
+	if (attr->batch.elem_flags & ~BPF_F_LOCK)
+		return -EINVAL;
+
+	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
+	    !map_value_has_spin_lock(map)) {
+		return -EINVAL;
+	}
+
+	value_size = bpf_map_value_size(map);
+
+	max_count = attr->batch.count;
+	if (!max_count)
+		return 0;
+
+	key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
+	if (!key)
+		return -ENOMEM;
+
+	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
+	if (!value) {
+		kfree(key);
+		return -ENOMEM;
+	}
+
+	f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */
+	for (cp = 0; cp < max_count; cp++) {
+		err = -EFAULT;
+		if (copy_from_user(key, keys + cp * map->key_size,
+		    map->key_size) ||
+		    copy_from_user(value, values + cp * value_size, value_size))
+			break;
+
+		err = bpf_map_update_value(map, f, key, value,
+					   attr->batch.elem_flags);
+
+		if (err)
+			break;
+		cond_resched();
+	}
+
+	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
+		err = -EFAULT;
+
+	kfree(value);
+	kfree(key);
+	fdput(f);
+	return err;
+}
+
+#define MAP_LOOKUP_RETRIES 3
+
+int generic_map_lookup_batch(struct bpf_map *map,
+				    const union bpf_attr *attr,
+				    union bpf_attr __user *uattr)
+{
+	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
+	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
+	void __user *values = u64_to_user_ptr(attr->batch.values);
+	void __user *keys = u64_to_user_ptr(attr->batch.keys);
+	void *buf, *buf_prevkey, *prev_key, *key, *value;
+	int err, retry = MAP_LOOKUP_RETRIES;
+	u32 value_size, cp, max_count;
+
+	if (attr->batch.elem_flags & ~BPF_F_LOCK)
+		return -EINVAL;
+
+	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
+	    !map_value_has_spin_lock(map))
+		return -EINVAL;
+
+	value_size = bpf_map_value_size(map);
+
+	max_count = attr->batch.count;
+	if (!max_count)
+		return 0;
+
+	if (put_user(0, &uattr->batch.count))
+		return -EFAULT;
+
+	buf_prevkey = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
+	if (!buf_prevkey)
+		return -ENOMEM;
+
+	buf = kmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
+	if (!buf) {
+		kfree(buf_prevkey);
+		return -ENOMEM;
+	}
+
+	err = -EFAULT;
+	prev_key = NULL;
+	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
+		goto free_buf;
+	key = buf;
+	value = key + map->key_size;
+	if (ubatch)
+		prev_key = buf_prevkey;
+
+	for (cp = 0; cp < max_count;) {
+		rcu_read_lock();
+		err = map->ops->map_get_next_key(map, prev_key, key);
+		rcu_read_unlock();
+		if (err)
+			break;
+		err = bpf_map_copy_value(map, key, value,
+					 attr->batch.elem_flags);
+
+		if (err == -ENOENT) {
+			if (retry) {
+				retry--;
+				continue;
+			}
+			err = -EINTR;
+			break;
+		}
+
+		if (err)
+			goto free_buf;
+
+		if (copy_to_user(keys + cp * map->key_size, key,
+				 map->key_size)) {
+			err = -EFAULT;
+			goto free_buf;
+		}
+		if (copy_to_user(values + cp * value_size, value, value_size)) {
+			err = -EFAULT;
+			goto free_buf;
+		}
+
+		if (!prev_key)
+			prev_key = buf_prevkey;
+
+		swap(prev_key, key);
+		retry = MAP_LOOKUP_RETRIES;
+		cp++;
+		cond_resched();
+	}
+
+	if (err == -EFAULT)
+		goto free_buf;
+
+	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
+		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
+		err = -EFAULT;
+
+free_buf:
+	kfree(buf_prevkey);
+	kfree(buf);
+	return err;
+}
+
+#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD value
+
+static int map_lookup_and_delete_elem(union bpf_attr *attr)
+{
+	void __user *ukey = u64_to_user_ptr(attr->key);
+	void __user *uvalue = u64_to_user_ptr(attr->value);
+	int ufd = attr->map_fd;
+	struct bpf_map *map;
+	void *key, *value;
+	u32 value_size;
+	struct fd f;
+	int err;
+
+	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
+		return -EINVAL;
+
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+	bpf_map_write_active_inc(map);
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
+	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	key = __bpf_copy_key(ukey, map->key_size);
+	if (IS_ERR(key)) {
+		err = PTR_ERR(key);
+		goto err_put;
+	}
+
+	value_size = map->value_size;
+
+	err = -ENOMEM;
+	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
+	if (!value)
+		goto free_key;
+
+	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
+	    map->map_type == BPF_MAP_TYPE_STACK) {
+		err = map->ops->map_pop_elem(map, value);
+	} else {
+		err = -ENOTSUPP;
+	}
+
+	if (err)
+		goto free_value;
+
+	if (copy_to_user(uvalue, value, value_size) != 0) {
+		err = -EFAULT;
+		goto free_value;
+	}
+
+	err = 0;
+
+free_value:
+	kfree(value);
+free_key:
+	kfree(key);
+err_put:
+	bpf_map_write_active_dec(map);
+	fdput(f);
+	return err;
+}
+
+#define BPF_MAP_FREEZE_LAST_FIELD map_fd
+
+static int map_freeze(const union bpf_attr *attr)
+{
+	int err = 0, ufd = attr->map_fd;
+	struct bpf_map *map;
+	struct fd f;
+
+	if (CHECK_ATTR(BPF_MAP_FREEZE))
+		return -EINVAL;
+
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		fdput(f);
+		return -ENOTSUPP;
+	}
+
+	mutex_lock(&map->freeze_mutex);
+	if (bpf_map_write_active(map)) {
+		err = -EBUSY;
+		goto err_put;
+	}
+	if (READ_ONCE(map->frozen)) {
+		err = -EBUSY;
+		goto err_put;
+	}
+	if (!bpf_capable()) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	WRITE_ONCE(map->frozen, true);
+err_put:
+	mutex_unlock(&map->freeze_mutex);
+	fdput(f);
+	return err;
+}
+
+static const struct bpf_prog_ops * const bpf_prog_types[] = {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	[_id] = & _name ## _prog_ops,
+#define BPF_MAP_TYPE(_id, _ops)
+#define BPF_LINK_TYPE(_id, _name)
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+#undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
+};
+
+static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
+{
+	const struct bpf_prog_ops *ops;
+
+	if (type >= ARRAY_SIZE(bpf_prog_types))
+		return -EINVAL;
+	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
+	ops = bpf_prog_types[type];
+	if (!ops)
+		return -EINVAL;
+
+	if (!bpf_prog_is_dev_bound(prog->aux))
+		prog->aux->ops = ops;
+	else
+		prog->aux->ops = &bpf_offload_prog_ops;
+	prog->type = type;
+	return 0;
+}
+
+enum bpf_audit {
+	BPF_AUDIT_LOAD,
+	BPF_AUDIT_UNLOAD,
+	BPF_AUDIT_MAX,
+};
+
+static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
+	[BPF_AUDIT_LOAD]   = "LOAD",
+	[BPF_AUDIT_UNLOAD] = "UNLOAD",
+};
+
+static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
+{
+	struct audit_context *ctx = NULL;
+	struct audit_buffer *ab;
+
+	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
+		return;
+	if (audit_enabled == AUDIT_OFF)
+		return;
+	if (op == BPF_AUDIT_LOAD)
+		ctx = audit_context();
+	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
+	if (unlikely(!ab))
+		return;
+	audit_log_format(ab, "prog-id=%u op=%s",
+			 prog->aux->id, bpf_audit_str[op]);
+	audit_log_end(ab);
+}
+
+int __bpf_prog_charge(struct user_struct *user, u32 pages)
+{
+	unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+	unsigned long user_bufs;
+
+	if (user) {
+		user_bufs = atomic_long_add_return(pages, &user->locked_vm);
+		if (user_bufs > memlock_limit) {
+			atomic_long_sub(pages, &user->locked_vm);
+			return -EPERM;
+		}
+	}
+
+	return 0;
+}
+
+void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
+{
+	if (user)
+		atomic_long_sub(pages, &user->locked_vm);
+}
+
+static int bpf_prog_charge_memlock(struct bpf_prog *prog)
+{
+	struct user_struct *user = get_current_user();
+	int ret;
+
+	ret = __bpf_prog_charge(user, prog->pages);
+	if (ret) {
+		free_uid(user);
+		return ret;
+	}
+
+	prog->aux->user = user;
+	return 0;
+}
+
+static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
+{
+	struct user_struct *user = prog->aux->user;
+
+	__bpf_prog_uncharge(user, prog->pages);
+	free_uid(user);
+}
+
+static int bpf_prog_alloc_id(struct bpf_prog *prog)
+{
+	int id;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock_bh(&prog_idr_lock);
+	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
+	if (id > 0)
+		prog->aux->id = id;
+	spin_unlock_bh(&prog_idr_lock);
+	idr_preload_end();
+
+	/* id is in [1, INT_MAX) */
+	if (WARN_ON_ONCE(!id))
+		return -ENOSPC;
+
+	return id > 0 ? 0 : id;
+}
+
+void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
+{
+	/* cBPF to eBPF migrations are currently not in the idr store.
+	 * Offloaded programs are removed from the store when their device
+	 * disappears - even if someone grabs an fd to them they are unusable,
+	 * simply waiting for refcnt to drop to be freed.
+	 */
+	if (!prog->aux->id)
+		return;
+
+	if (do_idr_lock)
+		spin_lock_bh(&prog_idr_lock);
+	else
+		__acquire(&prog_idr_lock);
+
+	idr_remove(&prog_idr, prog->aux->id);
+	prog->aux->id = 0;
+
+	if (do_idr_lock)
+		spin_unlock_bh(&prog_idr_lock);
+	else
+		__release(&prog_idr_lock);
+}
+
+static void __bpf_prog_put_rcu(struct rcu_head *rcu)
+{
+	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
+
+	kvfree(aux->func_info);
+	kfree(aux->func_info_aux);
+	bpf_prog_uncharge_memlock(aux->prog);
+	security_bpf_prog_free(aux);
+	bpf_prog_free(aux->prog);
+}
+
+static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
+{
+	bpf_prog_kallsyms_del_all(prog);
+	btf_put(prog->aux->btf);
+	bpf_prog_free_linfo(prog);
+
+	if (deferred) {
+		if (prog->aux->sleepable)
+			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
+		else
+			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
+	} else {
+		__bpf_prog_put_rcu(&prog->aux->rcu);
+	}
+}
+
+static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
+{
+	if (atomic64_dec_and_test(&prog->aux->refcnt)) {
+		perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
+		bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
+		/* bpf_prog_free_id() must be called first */
+		bpf_prog_free_id(prog, do_idr_lock);
+		__bpf_prog_put_noref(prog, true);
+	}
+}
+
+void bpf_prog_put(struct bpf_prog *prog)
+{
+	__bpf_prog_put(prog, true);
+}
+EXPORT_SYMBOL_GPL(bpf_prog_put);
+
+static int bpf_prog_release(struct inode *inode, struct file *filp)
+{
+	struct bpf_prog *prog = filp->private_data;
+
+	bpf_prog_put(prog);
+	return 0;
+}
+
+static void bpf_prog_get_stats(const struct bpf_prog *prog,
+			       struct bpf_prog_stats *stats)
+{
+	u64 nsecs = 0, cnt = 0;
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		const struct bpf_prog_stats *st;
+		unsigned int start;
+		u64 tnsecs, tcnt;
+
+		st = per_cpu_ptr(prog->aux->stats, cpu);
+		do {
+			start = u64_stats_fetch_begin_irq(&st->syncp);
+			tnsecs = st->nsecs;
+			tcnt = st->cnt;
+		} while (u64_stats_fetch_retry_irq(&st->syncp, start));
+		nsecs += tnsecs;
+		cnt += tcnt;
+	}
+	stats->nsecs = nsecs;
+	stats->cnt = cnt;
+}
+
+#ifdef CONFIG_PROC_FS
+static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
+{
+	const struct bpf_prog *prog = filp->private_data;
+	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
+	struct bpf_prog_stats stats;
+
+	bpf_prog_get_stats(prog, &stats);
+	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
+	seq_printf(m,
+		   "prog_type:\t%u\n"
+		   "prog_jited:\t%u\n"
+		   "prog_tag:\t%s\n"
+		   "memlock:\t%llu\n"
+		   "prog_id:\t%u\n"
+		   "run_time_ns:\t%llu\n"
+		   "run_cnt:\t%llu\n",
+		   prog->type,
+		   prog->jited,
+		   prog_tag,
+		   prog->pages * 1ULL << PAGE_SHIFT,
+		   prog->aux->id,
+		   stats.nsecs,
+		   stats.cnt);
+}
+#endif
+
+const struct file_operations bpf_prog_fops = {
+#ifdef CONFIG_PROC_FS
+	.show_fdinfo	= bpf_prog_show_fdinfo,
+#endif
+	.release	= bpf_prog_release,
+	.read		= bpf_dummy_read,
+	.write		= bpf_dummy_write,
+};
+
+int bpf_prog_new_fd(struct bpf_prog *prog)
+{
+	int ret;
+
+	ret = security_bpf_prog(prog);
+	if (ret < 0)
+		return ret;
+
+	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
+				O_RDWR | O_CLOEXEC);
+}
+
+static struct bpf_prog *____bpf_prog_get(struct fd f)
+{
+	if (!f.file)
+		return ERR_PTR(-EBADF);
+	if (f.file->f_op != &bpf_prog_fops) {
+		fdput(f);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return f.file->private_data;
+}
+
+void bpf_prog_add(struct bpf_prog *prog, int i)
+{
+	atomic64_add(i, &prog->aux->refcnt);
+}
+EXPORT_SYMBOL_GPL(bpf_prog_add);
+
+void bpf_prog_sub(struct bpf_prog *prog, int i)
+{
+	/* Only to be used for undoing previous bpf_prog_add() in some
+	 * error path. We still know that another entity in our call
+	 * path holds a reference to the program, thus atomic_sub() can
+	 * be safely used in such cases!
+	 */
+	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
+}
+EXPORT_SYMBOL_GPL(bpf_prog_sub);
+
+void bpf_prog_inc(struct bpf_prog *prog)
+{
+	atomic64_inc(&prog->aux->refcnt);
+}
+EXPORT_SYMBOL_GPL(bpf_prog_inc);
+
+/* prog_idr_lock should have been held */
+struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
+{
+	int refold;
+
+	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
+
+	if (!refold)
+		return ERR_PTR(-ENOENT);
+
+	return prog;
+}
+EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
+
+bool bpf_prog_get_ok(struct bpf_prog *prog,
+			    enum bpf_prog_type *attach_type, bool attach_drv)
+{
+	/* not an attachment, just a refcount inc, always allow */
+	if (!attach_type)
+		return true;
+
+	if (prog->type != *attach_type)
+		return false;
+	if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
+		return false;
+
+	return true;
+}
+
+static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
+				       bool attach_drv)
+{
+	struct fd f = fdget(ufd);
+	struct bpf_prog *prog;
+
+	prog = ____bpf_prog_get(f);
+	if (IS_ERR(prog))
+		return prog;
+	if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
+		prog = ERR_PTR(-EINVAL);
+		goto out;
+	}
+
+	bpf_prog_inc(prog);
+out:
+	fdput(f);
+	return prog;
+}
+
+struct bpf_prog *bpf_prog_get(u32 ufd)
+{
+	return __bpf_prog_get(ufd, NULL, false);
+}
+
+struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
+				       bool attach_drv)
+{
+	return __bpf_prog_get(ufd, &type, attach_drv);
+}
+EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
+
+/* Initially all BPF programs could be loaded w/o specifying
+ * expected_attach_type. Later for some of them specifying expected_attach_type
+ * at load time became required so that program could be validated properly.
+ * Programs of types that are allowed to be loaded both w/ and w/o (for
+ * backward compatibility) expected_attach_type, should have the default attach
+ * type assigned to expected_attach_type for the latter case, so that it can be
+ * validated later at attach time.
+ *
+ * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
+ * prog type requires it but has some attach types that have to be backward
+ * compatible.
+ */
+static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
+{
+	switch (attr->prog_type) {
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
+		 * exist so checking for non-zero is the way to go here.
+		 */
+		if (!attr->expected_attach_type)
+			attr->expected_attach_type =
+				BPF_CGROUP_INET_SOCK_CREATE;
+		break;
+	}
+}
+
+static int
+bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
+			   enum bpf_attach_type expected_attach_type,
+			   u32 btf_id, u32 prog_fd)
+{
+	if (btf_id) {
+		if (btf_id > BTF_MAX_TYPE)
+			return -EINVAL;
+
+		switch (prog_type) {
+		case BPF_PROG_TYPE_TRACING:
+		case BPF_PROG_TYPE_LSM:
+		case BPF_PROG_TYPE_STRUCT_OPS:
+		case BPF_PROG_TYPE_EXT:
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (prog_fd && prog_type != BPF_PROG_TYPE_TRACING &&
+	    prog_type != BPF_PROG_TYPE_EXT)
+		return -EINVAL;
+
+	switch (prog_type) {
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+		switch (expected_attach_type) {
+		case BPF_CGROUP_INET_SOCK_CREATE:
+		case BPF_CGROUP_INET_SOCK_RELEASE:
+		case BPF_CGROUP_INET4_POST_BIND:
+		case BPF_CGROUP_INET6_POST_BIND:
+			return 0;
+		default:
+			return -EINVAL;
+		}
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+		switch (expected_attach_type) {
+		case BPF_CGROUP_INET4_BIND:
+		case BPF_CGROUP_INET6_BIND:
+		case BPF_CGROUP_INET4_CONNECT:
+		case BPF_CGROUP_INET6_CONNECT:
+		case BPF_CGROUP_INET4_GETPEERNAME:
+		case BPF_CGROUP_INET6_GETPEERNAME:
+		case BPF_CGROUP_INET4_GETSOCKNAME:
+		case BPF_CGROUP_INET6_GETSOCKNAME:
+		case BPF_CGROUP_UDP4_SENDMSG:
+		case BPF_CGROUP_UDP6_SENDMSG:
+		case BPF_CGROUP_UDP4_RECVMSG:
+		case BPF_CGROUP_UDP6_RECVMSG:
+			return 0;
+		default:
+			return -EINVAL;
+		}
+	case BPF_PROG_TYPE_CGROUP_SKB:
+		switch (expected_attach_type) {
+		case BPF_CGROUP_INET_INGRESS:
+		case BPF_CGROUP_INET_EGRESS:
+			return 0;
+		default:
+			return -EINVAL;
+		}
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+		switch (expected_attach_type) {
+		case BPF_CGROUP_SETSOCKOPT:
+		case BPF_CGROUP_GETSOCKOPT:
+			return 0;
+		default:
+			return -EINVAL;
+		}
+	case BPF_PROG_TYPE_SK_LOOKUP:
+		if (expected_attach_type == BPF_SK_LOOKUP)
+			return 0;
+		return -EINVAL;
+	case BPF_PROG_TYPE_EXT:
+		if (expected_attach_type)
+			return -EINVAL;
+		fallthrough;
+	default:
+		return 0;
+	}
+}
+
+static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
+{
+	switch (prog_type) {
+	case BPF_PROG_TYPE_SCHED_CLS:
+	case BPF_PROG_TYPE_SCHED_ACT:
+	case BPF_PROG_TYPE_XDP:
+	case BPF_PROG_TYPE_LWT_IN:
+	case BPF_PROG_TYPE_LWT_OUT:
+	case BPF_PROG_TYPE_LWT_XMIT:
+	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
+	case BPF_PROG_TYPE_SK_SKB:
+	case BPF_PROG_TYPE_SK_MSG:
+	case BPF_PROG_TYPE_LIRC_MODE2:
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
+	case BPF_PROG_TYPE_SOCK_OPS:
+	case BPF_PROG_TYPE_EXT: /* extends any prog */
+		return true;
+	case BPF_PROG_TYPE_CGROUP_SKB:
+		/* always unpriv */
+	case BPF_PROG_TYPE_SK_REUSEPORT:
+		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
+	default:
+		return false;
+	}
+}
+
+static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
+{
+	switch (prog_type) {
+	case BPF_PROG_TYPE_KPROBE:
+	case BPF_PROG_TYPE_TRACEPOINT:
+	case BPF_PROG_TYPE_PERF_EVENT:
+	case BPF_PROG_TYPE_RAW_TRACEPOINT:
+	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
+	case BPF_PROG_TYPE_TRACING:
+	case BPF_PROG_TYPE_LSM:
+	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
+	case BPF_PROG_TYPE_EXT: /* extends any prog */
+		return true;
+	default:
+		return false;
+	}
+}
+
+/* last field in 'union bpf_attr' used by this command */
+#define	BPF_PROG_LOAD_LAST_FIELD attach_prog_fd
+
+static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
+{
+	enum bpf_prog_type type = attr->prog_type;
+	struct bpf_prog *prog;
+	int err;
+	char license[128];
+	bool is_gpl;
+
+	if (CHECK_ATTR(BPF_PROG_LOAD))
+		return -EINVAL;
+
+	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
+				 BPF_F_ANY_ALIGNMENT |
+				 BPF_F_TEST_STATE_FREQ |
+				 BPF_F_SLEEPABLE |
+				 BPF_F_TEST_RND_HI32))
+		return -EINVAL;
+
+	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
+	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
+	    !bpf_capable())
+		return -EPERM;
+
+	/* copy eBPF program license from user space */
+	if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
+			      sizeof(license) - 1) < 0)
+		return -EFAULT;
+	license[sizeof(license) - 1] = 0;
+
+	/* eBPF programs must be GPL compatible to use GPL-ed functions */
+	is_gpl = license_is_gpl_compatible(license);
+
+	if (attr->insn_cnt == 0 ||
+	    attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
+		return -E2BIG;
+	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
+	    type != BPF_PROG_TYPE_CGROUP_SKB &&
+	    !bpf_capable())
+		return -EPERM;
+
+	if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (is_perfmon_prog_type(type) && !perfmon_capable())
+		return -EPERM;
+
+	bpf_prog_load_fixup_attach_type(attr);
+	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
+				       attr->attach_btf_id,
+				       attr->attach_prog_fd))
+		return -EINVAL;
+
+	/* plain bpf_prog allocation */
+	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
+	if (!prog)
+		return -ENOMEM;
+
+	prog->expected_attach_type = attr->expected_attach_type;
+	prog->aux->attach_btf_id = attr->attach_btf_id;
+	if (attr->attach_prog_fd) {
+		struct bpf_prog *dst_prog;
+
+		dst_prog = bpf_prog_get(attr->attach_prog_fd);
+		if (IS_ERR(dst_prog)) {
+			err = PTR_ERR(dst_prog);
+			goto free_prog_nouncharge;
+		}
+		prog->aux->dst_prog = dst_prog;
+	}
+
+	prog->aux->offload_requested = !!attr->prog_ifindex;
+	prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
+
+	err = security_bpf_prog_alloc(prog->aux);
+	if (err)
+		goto free_prog_nouncharge;
+
+	err = bpf_prog_charge_memlock(prog);
+	if (err)
+		goto free_prog_sec;
+
+	prog->len = attr->insn_cnt;
+
+	err = -EFAULT;
+	if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
+			   bpf_prog_insn_size(prog)) != 0)
+		goto free_prog;
+
+	prog->orig_prog = NULL;
+	prog->jited = 0;
+
+	atomic64_set(&prog->aux->refcnt, 1);
+	prog->gpl_compatible = is_gpl ? 1 : 0;
+
+	if (bpf_prog_is_dev_bound(prog->aux)) {
+		err = bpf_prog_offload_init(prog, attr);
+		if (err)
+			goto free_prog;
+	}
+
+	/* find program type: socket_filter vs tracing_filter */
+	err = find_prog_type(type, prog);
+	if (err < 0)
+		goto free_prog;
+
+	prog->aux->load_time = ktime_get_boottime_ns();
+	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
+			       sizeof(attr->prog_name));
+	if (err < 0)
+		goto free_prog;
+
+	/* run eBPF verifier */
+	err = bpf_check(&prog, attr, uattr);
+	if (err < 0)
+		goto free_used_maps;
+
+	prog = bpf_prog_select_runtime(prog, &err);
+	if (err < 0)
+		goto free_used_maps;
+
+	err = bpf_prog_alloc_id(prog);
+	if (err)
+		goto free_used_maps;
+
+	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
+	 * effectively publicly exposed. However, retrieving via
+	 * bpf_prog_get_fd_by_id() will take another reference,
+	 * therefore it cannot be gone underneath us.
+	 *
+	 * Only for the time /after/ successful bpf_prog_new_fd()
+	 * and before returning to userspace, we might just hold
+	 * one reference and any parallel close on that fd could
+	 * rip everything out. Hence, below notifications must
+	 * happen before bpf_prog_new_fd().
+	 *
+	 * Also, any failure handling from this point onwards must
+	 * be using bpf_prog_put() given the program is exposed.
+	 */
+	bpf_prog_kallsyms_add(prog);
+	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
+	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
+
+	err = bpf_prog_new_fd(prog);
+	if (err < 0)
+		bpf_prog_put(prog);
+	return err;
+
+free_used_maps:
+	/* In case we have subprogs, we need to wait for a grace
+	 * period before we can tear down JIT memory since symbols
+	 * are already exposed under kallsyms.
+	 */
+	__bpf_prog_put_noref(prog, prog->aux->func_cnt);
+	return err;
+free_prog:
+	bpf_prog_uncharge_memlock(prog);
+free_prog_sec:
+	security_bpf_prog_free(prog->aux);
+free_prog_nouncharge:
+	bpf_prog_free(prog);
+	return err;
+}
+
+#define BPF_OBJ_LAST_FIELD file_flags
+
+static int bpf_obj_pin(const union bpf_attr *attr)
+{
+	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
+		return -EINVAL;
+
+	return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
+}
+
+static int bpf_obj_get(const union bpf_attr *attr)
+{
+	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
+	    attr->file_flags & ~BPF_OBJ_FLAG_MASK)
+		return -EINVAL;
+
+	return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
+				attr->file_flags);
+}
+
+void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
+		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
+{
+	atomic64_set(&link->refcnt, 1);
+	link->type = type;
+	link->id = 0;
+	link->ops = ops;
+	link->prog = prog;
+}
+
+static void bpf_link_free_id(int id)
+{
+	if (!id)
+		return;
+
+	spin_lock_bh(&link_idr_lock);
+	idr_remove(&link_idr, id);
+	spin_unlock_bh(&link_idr_lock);
+}
+
+/* Clean up bpf_link and corresponding anon_inode file and FD. After
+ * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
+ * anon_inode's release() call. This helper marksbpf_link as
+ * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
+ * is not decremented, it's the responsibility of a calling code that failed
+ * to complete bpf_link initialization.
+ */
+void bpf_link_cleanup(struct bpf_link_primer *primer)
+{
+	primer->link->prog = NULL;
+	bpf_link_free_id(primer->id);
+	fput(primer->file);
+	put_unused_fd(primer->fd);
+}
+
+void bpf_link_inc(struct bpf_link *link)
+{
+	atomic64_inc(&link->refcnt);
+}
+
+/* bpf_link_free is guaranteed to be called from process context */
+static void bpf_link_free(struct bpf_link *link)
+{
+	bpf_link_free_id(link->id);
+	if (link->prog) {
+		/* detach BPF program, clean up used resources */
+		link->ops->release(link);
+		bpf_prog_put(link->prog);
+	}
+	/* free bpf_link and its containing memory */
+	link->ops->dealloc(link);
+}
+
+static void bpf_link_put_deferred(struct work_struct *work)
+{
+	struct bpf_link *link = container_of(work, struct bpf_link, work);
+
+	bpf_link_free(link);
+}
+
+/* bpf_link_put can be called from atomic context, but ensures that resources
+ * are freed from process context
+ */
+void bpf_link_put(struct bpf_link *link)
+{
+	if (!atomic64_dec_and_test(&link->refcnt))
+		return;
+
+	if (in_atomic()) {
+		INIT_WORK(&link->work, bpf_link_put_deferred);
+		schedule_work(&link->work);
+	} else {
+		bpf_link_free(link);
+	}
+}
+
+static int bpf_link_release(struct inode *inode, struct file *filp)
+{
+	struct bpf_link *link = filp->private_data;
+
+	bpf_link_put(link);
+	return 0;
+}
+
+#ifdef CONFIG_PROC_FS
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
+#define BPF_MAP_TYPE(_id, _ops)
+#define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
+static const char *bpf_link_type_strs[] = {
+	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
+#include <linux/bpf_types.h>
+};
+#undef BPF_PROG_TYPE
+#undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
+
+static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
+{
+	const struct bpf_link *link = filp->private_data;
+	const struct bpf_prog *prog = link->prog;
+	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
+
+	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
+	seq_printf(m,
+		   "link_type:\t%s\n"
+		   "link_id:\t%u\n"
+		   "prog_tag:\t%s\n"
+		   "prog_id:\t%u\n",
+		   bpf_link_type_strs[link->type],
+		   link->id,
+		   prog_tag,
+		   prog->aux->id);
+	if (link->ops->show_fdinfo)
+		link->ops->show_fdinfo(link, m);
+}
+#endif
+
+static const struct file_operations bpf_link_fops = {
+#ifdef CONFIG_PROC_FS
+	.show_fdinfo	= bpf_link_show_fdinfo,
+#endif
+	.release	= bpf_link_release,
+	.read		= bpf_dummy_read,
+	.write		= bpf_dummy_write,
+};
+
+static int bpf_link_alloc_id(struct bpf_link *link)
+{
+	int id;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock_bh(&link_idr_lock);
+	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
+	spin_unlock_bh(&link_idr_lock);
+	idr_preload_end();
+
+	return id;
+}
+
+/* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
+ * reserving unused FD and allocating ID from link_idr. This is to be paired
+ * with bpf_link_settle() to install FD and ID and expose bpf_link to
+ * user-space, if bpf_link is successfully attached. If not, bpf_link and
+ * pre-allocated resources are to be freed with bpf_cleanup() call. All the
+ * transient state is passed around in struct bpf_link_primer.
+ * This is preferred way to create and initialize bpf_link, especially when
+ * there are complicated and expensive operations inbetween creating bpf_link
+ * itself and attaching it to BPF hook. By using bpf_link_prime() and
+ * bpf_link_settle() kernel code using bpf_link doesn't have to perform
+ * expensive (and potentially failing) roll back operations in a rare case
+ * that file, FD, or ID can't be allocated.
+ */
+int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
+{
+	struct file *file;
+	int fd, id;
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0)
+		return fd;
+
+
+	id = bpf_link_alloc_id(link);
+	if (id < 0) {
+		put_unused_fd(fd);
+		return id;
+	}
+
+	file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
+	if (IS_ERR(file)) {
+		bpf_link_free_id(id);
+		put_unused_fd(fd);
+		return PTR_ERR(file);
+	}
+
+	primer->link = link;
+	primer->file = file;
+	primer->fd = fd;
+	primer->id = id;
+	return 0;
+}
+
+int bpf_link_settle(struct bpf_link_primer *primer)
+{
+	/* make bpf_link fetchable by ID */
+	spin_lock_bh(&link_idr_lock);
+	primer->link->id = primer->id;
+	spin_unlock_bh(&link_idr_lock);
+	/* make bpf_link fetchable by FD */
+	fd_install(primer->fd, primer->file);
+	/* pass through installed FD */
+	return primer->fd;
+}
+
+int bpf_link_new_fd(struct bpf_link *link)
+{
+	return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
+}
+
+struct bpf_link *bpf_link_get_from_fd(u32 ufd)
+{
+	struct fd f = fdget(ufd);
+	struct bpf_link *link;
+
+	if (!f.file)
+		return ERR_PTR(-EBADF);
+	if (f.file->f_op != &bpf_link_fops) {
+		fdput(f);
+		return ERR_PTR(-EINVAL);
+	}
+
+	link = f.file->private_data;
+	bpf_link_inc(link);
+	fdput(f);
+
+	return link;
+}
+
+struct bpf_tracing_link {
+	struct bpf_link link;
+	enum bpf_attach_type attach_type;
+	struct bpf_trampoline *trampoline;
+	struct bpf_prog *tgt_prog;
+};
+
+static void bpf_tracing_link_release(struct bpf_link *link)
+{
+	struct bpf_tracing_link *tr_link =
+		container_of(link, struct bpf_tracing_link, link);
+
+	WARN_ON_ONCE(bpf_trampoline_unlink_prog(link->prog,
+						tr_link->trampoline));
+
+	bpf_trampoline_put(tr_link->trampoline);
+
+	/* tgt_prog is NULL if target is a kernel function */
+	if (tr_link->tgt_prog)
+		bpf_prog_put(tr_link->tgt_prog);
+}
+
+static void bpf_tracing_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_tracing_link *tr_link =
+		container_of(link, struct bpf_tracing_link, link);
+
+	kfree(tr_link);
+}
+
+static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
+					 struct seq_file *seq)
+{
+	struct bpf_tracing_link *tr_link =
+		container_of(link, struct bpf_tracing_link, link);
+
+	seq_printf(seq,
+		   "attach_type:\t%d\n",
+		   tr_link->attach_type);
+}
+
+static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
+					   struct bpf_link_info *info)
+{
+	struct bpf_tracing_link *tr_link =
+		container_of(link, struct bpf_tracing_link, link);
+
+	info->tracing.attach_type = tr_link->attach_type;
+
+	return 0;
+}
+
+static const struct bpf_link_ops bpf_tracing_link_lops = {
+	.release = bpf_tracing_link_release,
+	.dealloc = bpf_tracing_link_dealloc,
+	.show_fdinfo = bpf_tracing_link_show_fdinfo,
+	.fill_link_info = bpf_tracing_link_fill_link_info,
+};
+
+static int bpf_tracing_prog_attach(struct bpf_prog *prog,
+				   int tgt_prog_fd,
+				   u32 btf_id)
+{
+	struct bpf_link_primer link_primer;
+	struct bpf_prog *tgt_prog = NULL;
+	struct bpf_trampoline *tr = NULL;
+	struct bpf_tracing_link *link;
+	u64 key = 0;
+	int err;
+
+	switch (prog->type) {
+	case BPF_PROG_TYPE_TRACING:
+		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
+		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
+		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+		break;
+	case BPF_PROG_TYPE_EXT:
+		if (prog->expected_attach_type != 0) {
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+		break;
+	case BPF_PROG_TYPE_LSM:
+		if (prog->expected_attach_type != BPF_LSM_MAC) {
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+		break;
+	default:
+		err = -EINVAL;
+		goto out_put_prog;
+	}
+
+	if (!!tgt_prog_fd != !!btf_id) {
+		err = -EINVAL;
+		goto out_put_prog;
+	}
+
+	if (tgt_prog_fd) {
+		/* For now we only allow new targets for BPF_PROG_TYPE_EXT */
+		if (prog->type != BPF_PROG_TYPE_EXT) {
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+
+		tgt_prog = bpf_prog_get(tgt_prog_fd);
+		if (IS_ERR(tgt_prog)) {
+			err = PTR_ERR(tgt_prog);
+			tgt_prog = NULL;
+			goto out_put_prog;
+		}
+
+		key = bpf_trampoline_compute_key(tgt_prog, btf_id);
+	}
+
+	link = kzalloc(sizeof(*link), GFP_USER);
+	if (!link) {
+		err = -ENOMEM;
+		goto out_put_prog;
+	}
+	bpf_link_init(&link->link, BPF_LINK_TYPE_TRACING,
+		      &bpf_tracing_link_lops, prog);
+	link->attach_type = prog->expected_attach_type;
+
+	mutex_lock(&prog->aux->dst_mutex);
+
+	/* There are a few possible cases here:
+	 *
+	 * - if prog->aux->dst_trampoline is set, the program was just loaded
+	 *   and not yet attached to anything, so we can use the values stored
+	 *   in prog->aux
+	 *
+	 * - if prog->aux->dst_trampoline is NULL, the program has already been
+         *   attached to a target and its initial target was cleared (below)
+	 *
+	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
+	 *   target_btf_id using the link_create API.
+	 *
+	 * - if tgt_prog == NULL when this function was called using the old
+         *   raw_tracepoint_open API, and we need a target from prog->aux
+         *
+         * The combination of no saved target in prog->aux, and no target
+         * specified on load is illegal, and we reject that here.
+	 */
+	if (!prog->aux->dst_trampoline && !tgt_prog) {
+		err = -ENOENT;
+		goto out_unlock;
+	}
+
+	if (!prog->aux->dst_trampoline ||
+	    (key && key != prog->aux->dst_trampoline->key)) {
+		/* If there is no saved target, or the specified target is
+		 * different from the destination specified at load time, we
+		 * need a new trampoline and a check for compatibility
+		 */
+		struct bpf_attach_target_info tgt_info = {};
+
+		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
+					      &tgt_info);
+		if (err)
+			goto out_unlock;
+
+		tr = bpf_trampoline_get(key, &tgt_info);
+		if (!tr) {
+			err = -ENOMEM;
+			goto out_unlock;
+		}
+	} else {
+		/* The caller didn't specify a target, or the target was the
+		 * same as the destination supplied during program load. This
+		 * means we can reuse the trampoline and reference from program
+		 * load time, and there is no need to allocate a new one. This
+		 * can only happen once for any program, as the saved values in
+		 * prog->aux are cleared below.
+		 */
+		tr = prog->aux->dst_trampoline;
+		tgt_prog = prog->aux->dst_prog;
+	}
+
+	err = bpf_link_prime(&link->link, &link_primer);
+	if (err)
+		goto out_unlock;
+
+	err = bpf_trampoline_link_prog(prog, tr);
+	if (err) {
+		bpf_link_cleanup(&link_primer);
+		link = NULL;
+		goto out_unlock;
+	}
+
+	link->tgt_prog = tgt_prog;
+	link->trampoline = tr;
+
+	/* Always clear the trampoline and target prog from prog->aux to make
+	 * sure the original attach destination is not kept alive after a
+	 * program is (re-)attached to another target.
+	 */
+	if (prog->aux->dst_prog &&
+	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
+		/* got extra prog ref from syscall, or attaching to different prog */
+		bpf_prog_put(prog->aux->dst_prog);
+	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
+		/* we allocated a new trampoline, so free the old one */
+		bpf_trampoline_put(prog->aux->dst_trampoline);
+
+	prog->aux->dst_prog = NULL;
+	prog->aux->dst_trampoline = NULL;
+	mutex_unlock(&prog->aux->dst_mutex);
+
+	return bpf_link_settle(&link_primer);
+out_unlock:
+	if (tr && tr != prog->aux->dst_trampoline)
+		bpf_trampoline_put(tr);
+	mutex_unlock(&prog->aux->dst_mutex);
+	kfree(link);
+out_put_prog:
+	if (tgt_prog_fd && tgt_prog)
+		bpf_prog_put(tgt_prog);
+	return err;
+}
+
+struct bpf_raw_tp_link {
+	struct bpf_link link;
+	struct bpf_raw_event_map *btp;
+};
+
+static void bpf_raw_tp_link_release(struct bpf_link *link)
+{
+	struct bpf_raw_tp_link *raw_tp =
+		container_of(link, struct bpf_raw_tp_link, link);
+
+	bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
+	bpf_put_raw_tracepoint(raw_tp->btp);
+}
+
+static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_raw_tp_link *raw_tp =
+		container_of(link, struct bpf_raw_tp_link, link);
+
+	kfree(raw_tp);
+}
+
+static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
+					struct seq_file *seq)
+{
+	struct bpf_raw_tp_link *raw_tp_link =
+		container_of(link, struct bpf_raw_tp_link, link);
+
+	seq_printf(seq,
+		   "tp_name:\t%s\n",
+		   raw_tp_link->btp->tp->name);
+}
+
+static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
+					  struct bpf_link_info *info)
+{
+	struct bpf_raw_tp_link *raw_tp_link =
+		container_of(link, struct bpf_raw_tp_link, link);
+	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
+	const char *tp_name = raw_tp_link->btp->tp->name;
+	u32 ulen = info->raw_tracepoint.tp_name_len;
+	size_t tp_len = strlen(tp_name);
+
+	if (!ulen ^ !ubuf)
+		return -EINVAL;
+
+	info->raw_tracepoint.tp_name_len = tp_len + 1;
+
+	if (!ubuf)
+		return 0;
+
+	if (ulen >= tp_len + 1) {
+		if (copy_to_user(ubuf, tp_name, tp_len + 1))
+			return -EFAULT;
+	} else {
+		char zero = '\0';
+
+		if (copy_to_user(ubuf, tp_name, ulen - 1))
+			return -EFAULT;
+		if (put_user(zero, ubuf + ulen - 1))
+			return -EFAULT;
+		return -ENOSPC;
+	}
+
+	return 0;
+}
+
+static const struct bpf_link_ops bpf_raw_tp_link_lops = {
+	.release = bpf_raw_tp_link_release,
+	.dealloc = bpf_raw_tp_link_dealloc,
+	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
+	.fill_link_info = bpf_raw_tp_link_fill_link_info,
+};
+
+#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
+
+static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
+{
+	struct bpf_link_primer link_primer;
+	struct bpf_raw_tp_link *link;
+	struct bpf_raw_event_map *btp;
+	struct bpf_prog *prog;
+	const char *tp_name;
+	char buf[128];
+	int err;
+
+	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
+		return -EINVAL;
+
+	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	switch (prog->type) {
+	case BPF_PROG_TYPE_TRACING:
+	case BPF_PROG_TYPE_EXT:
+	case BPF_PROG_TYPE_LSM:
+		if (attr->raw_tracepoint.name) {
+			/* The attach point for this category of programs
+			 * should be specified via btf_id during program load.
+			 */
+			err = -EINVAL;
+			goto out_put_prog;
+		}
+		if (prog->type == BPF_PROG_TYPE_TRACING &&
+		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
+			tp_name = prog->aux->attach_func_name;
+			break;
+		}
+		err = bpf_tracing_prog_attach(prog, 0, 0);
+		if (err >= 0)
+			return err;
+		goto out_put_prog;
+	case BPF_PROG_TYPE_RAW_TRACEPOINT:
+	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
+		if (strncpy_from_user(buf,
+				      u64_to_user_ptr(attr->raw_tracepoint.name),
+				      sizeof(buf) - 1) < 0) {
+			err = -EFAULT;
+			goto out_put_prog;
+		}
+		buf[sizeof(buf) - 1] = 0;
+		tp_name = buf;
+		break;
+	default:
+		err = -EINVAL;
+		goto out_put_prog;
+	}
+
+	btp = bpf_get_raw_tracepoint(tp_name);
+	if (!btp) {
+		err = -ENOENT;
+		goto out_put_prog;
+	}
+
+	link = kzalloc(sizeof(*link), GFP_USER);
+	if (!link) {
+		err = -ENOMEM;
+		goto out_put_btp;
+	}
+	bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
+		      &bpf_raw_tp_link_lops, prog);
+	link->btp = btp;
+
+	err = bpf_link_prime(&link->link, &link_primer);
+	if (err) {
+		kfree(link);
+		goto out_put_btp;
+	}
+
+	err = bpf_probe_register(link->btp, prog);
+	if (err) {
+		bpf_link_cleanup(&link_primer);
+		goto out_put_btp;
+	}
+
+	return bpf_link_settle(&link_primer);
+
+out_put_btp:
+	bpf_put_raw_tracepoint(btp);
+out_put_prog:
+	bpf_prog_put(prog);
+	return err;
+}
+
+static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
+					     enum bpf_attach_type attach_type)
+{
+	switch (prog->type) {
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+	case BPF_PROG_TYPE_SK_LOOKUP:
+		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
+	case BPF_PROG_TYPE_CGROUP_SKB:
+		if (!capable(CAP_NET_ADMIN))
+			/* cg-skb progs can be loaded by unpriv user.
+			 * check permissions at attach time.
+			 */
+			return -EPERM;
+		return prog->enforce_expected_attach_type &&
+			prog->expected_attach_type != attach_type ?
+			-EINVAL : 0;
+	default:
+		return 0;
+	}
+}
+
+static enum bpf_prog_type
+attach_type_to_prog_type(enum bpf_attach_type attach_type)
+{
+	switch (attach_type) {
+	case BPF_CGROUP_INET_INGRESS:
+	case BPF_CGROUP_INET_EGRESS:
+		return BPF_PROG_TYPE_CGROUP_SKB;
+	case BPF_CGROUP_INET_SOCK_CREATE:
+	case BPF_CGROUP_INET_SOCK_RELEASE:
+	case BPF_CGROUP_INET4_POST_BIND:
+	case BPF_CGROUP_INET6_POST_BIND:
+		return BPF_PROG_TYPE_CGROUP_SOCK;
+	case BPF_CGROUP_INET4_BIND:
+	case BPF_CGROUP_INET6_BIND:
+	case BPF_CGROUP_INET4_CONNECT:
+	case BPF_CGROUP_INET6_CONNECT:
+	case BPF_CGROUP_INET4_GETPEERNAME:
+	case BPF_CGROUP_INET6_GETPEERNAME:
+	case BPF_CGROUP_INET4_GETSOCKNAME:
+	case BPF_CGROUP_INET6_GETSOCKNAME:
+	case BPF_CGROUP_UDP4_SENDMSG:
+	case BPF_CGROUP_UDP6_SENDMSG:
+	case BPF_CGROUP_UDP4_RECVMSG:
+	case BPF_CGROUP_UDP6_RECVMSG:
+		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
+	case BPF_CGROUP_SOCK_OPS:
+		return BPF_PROG_TYPE_SOCK_OPS;
+	case BPF_CGROUP_DEVICE:
+		return BPF_PROG_TYPE_CGROUP_DEVICE;
+	case BPF_SK_MSG_VERDICT:
+		return BPF_PROG_TYPE_SK_MSG;
+	case BPF_SK_SKB_STREAM_PARSER:
+	case BPF_SK_SKB_STREAM_VERDICT:
+		return BPF_PROG_TYPE_SK_SKB;
+	case BPF_LIRC_MODE2:
+		return BPF_PROG_TYPE_LIRC_MODE2;
+	case BPF_FLOW_DISSECTOR:
+		return BPF_PROG_TYPE_FLOW_DISSECTOR;
+	case BPF_CGROUP_SYSCTL:
+		return BPF_PROG_TYPE_CGROUP_SYSCTL;
+	case BPF_CGROUP_GETSOCKOPT:
+	case BPF_CGROUP_SETSOCKOPT:
+		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
+	case BPF_TRACE_ITER:
+		return BPF_PROG_TYPE_TRACING;
+	case BPF_SK_LOOKUP:
+		return BPF_PROG_TYPE_SK_LOOKUP;
+	case BPF_XDP:
+		return BPF_PROG_TYPE_XDP;
+	default:
+		return BPF_PROG_TYPE_UNSPEC;
+	}
+}
+
+#define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd
+
+#define BPF_F_ATTACH_MASK \
+	(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)
+
+static int bpf_prog_attach(const union bpf_attr *attr)
+{
+	enum bpf_prog_type ptype;
+	struct bpf_prog *prog;
+	int ret;
+
+	if (CHECK_ATTR(BPF_PROG_ATTACH))
+		return -EINVAL;
+
+	if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
+		return -EINVAL;
+
+	ptype = attach_type_to_prog_type(attr->attach_type);
+	if (ptype == BPF_PROG_TYPE_UNSPEC)
+		return -EINVAL;
+
+	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
+		bpf_prog_put(prog);
+		return -EINVAL;
+	}
+
+	switch (ptype) {
+	case BPF_PROG_TYPE_SK_SKB:
+	case BPF_PROG_TYPE_SK_MSG:
+		ret = sock_map_get_from_fd(attr, prog);
+		break;
+	case BPF_PROG_TYPE_LIRC_MODE2:
+		ret = lirc_prog_attach(attr, prog);
+		break;
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+		ret = netns_bpf_prog_attach(attr, prog);
+		break;
+	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SKB:
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
+	case BPF_PROG_TYPE_SOCK_OPS:
+		ret = cgroup_bpf_prog_attach(attr, ptype, prog);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		bpf_prog_put(prog);
+	return ret;
+}
+
+#define BPF_PROG_DETACH_LAST_FIELD attach_type
+
+static int bpf_prog_detach(const union bpf_attr *attr)
+{
+	enum bpf_prog_type ptype;
+
+	if (CHECK_ATTR(BPF_PROG_DETACH))
+		return -EINVAL;
+
+	ptype = attach_type_to_prog_type(attr->attach_type);
+
+	switch (ptype) {
+	case BPF_PROG_TYPE_SK_MSG:
+	case BPF_PROG_TYPE_SK_SKB:
+		return sock_map_prog_detach(attr, ptype);
+	case BPF_PROG_TYPE_LIRC_MODE2:
+		return lirc_prog_detach(attr);
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+		return netns_bpf_prog_detach(attr, ptype);
+	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SKB:
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
+	case BPF_PROG_TYPE_SOCK_OPS:
+		return cgroup_bpf_prog_detach(attr, ptype);
+	default:
+		return -EINVAL;
+	}
+}
+
+#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
+
+static int bpf_prog_query(const union bpf_attr *attr,
+			  union bpf_attr __user *uattr)
+{
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+	if (CHECK_ATTR(BPF_PROG_QUERY))
+		return -EINVAL;
+	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
+		return -EINVAL;
+
+	switch (attr->query.attach_type) {
+	case BPF_CGROUP_INET_INGRESS:
+	case BPF_CGROUP_INET_EGRESS:
+	case BPF_CGROUP_INET_SOCK_CREATE:
+	case BPF_CGROUP_INET_SOCK_RELEASE:
+	case BPF_CGROUP_INET4_BIND:
+	case BPF_CGROUP_INET6_BIND:
+	case BPF_CGROUP_INET4_POST_BIND:
+	case BPF_CGROUP_INET6_POST_BIND:
+	case BPF_CGROUP_INET4_CONNECT:
+	case BPF_CGROUP_INET6_CONNECT:
+	case BPF_CGROUP_INET4_GETPEERNAME:
+	case BPF_CGROUP_INET6_GETPEERNAME:
+	case BPF_CGROUP_INET4_GETSOCKNAME:
+	case BPF_CGROUP_INET6_GETSOCKNAME:
+	case BPF_CGROUP_UDP4_SENDMSG:
+	case BPF_CGROUP_UDP6_SENDMSG:
+	case BPF_CGROUP_UDP4_RECVMSG:
+	case BPF_CGROUP_UDP6_RECVMSG:
+	case BPF_CGROUP_SOCK_OPS:
+	case BPF_CGROUP_DEVICE:
+	case BPF_CGROUP_SYSCTL:
+	case BPF_CGROUP_GETSOCKOPT:
+	case BPF_CGROUP_SETSOCKOPT:
+		return cgroup_bpf_prog_query(attr, uattr);
+	case BPF_LIRC_MODE2:
+		return lirc_prog_query(attr, uattr);
+	case BPF_FLOW_DISSECTOR:
+	case BPF_SK_LOOKUP:
+		return netns_bpf_prog_query(attr, uattr);
+	default:
+		return -EINVAL;
+	}
+}
+
+#define BPF_PROG_TEST_RUN_LAST_FIELD test.cpu
+
+static int bpf_prog_test_run(const union bpf_attr *attr,
+			     union bpf_attr __user *uattr)
+{
+	struct bpf_prog *prog;
+	int ret = -ENOTSUPP;
+
+	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
+		return -EINVAL;
+
+	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
+	    (!attr->test.ctx_size_in && attr->test.ctx_in))
+		return -EINVAL;
+
+	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
+	    (!attr->test.ctx_size_out && attr->test.ctx_out))
+		return -EINVAL;
+
+	prog = bpf_prog_get(attr->test.prog_fd);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	if (prog->aux->ops->test_run)
+		ret = prog->aux->ops->test_run(prog, attr, uattr);
+
+	bpf_prog_put(prog);
+	return ret;
+}
+
+#define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
+
+static int bpf_obj_get_next_id(const union bpf_attr *attr,
+			       union bpf_attr __user *uattr,
+			       struct idr *idr,
+			       spinlock_t *lock)
+{
+	u32 next_id = attr->start_id;
+	int err = 0;
+
+	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
+		return -EINVAL;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	next_id++;
+	spin_lock_bh(lock);
+	if (!idr_get_next(idr, &next_id))
+		err = -ENOENT;
+	spin_unlock_bh(lock);
+
+	if (!err)
+		err = put_user(next_id, &uattr->next_id);
+
+	return err;
+}
+
+struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
+{
+	struct bpf_map *map;
+
+	spin_lock_bh(&map_idr_lock);
+again:
+	map = idr_get_next(&map_idr, id);
+	if (map) {
+		map = __bpf_map_inc_not_zero(map, false);
+		if (IS_ERR(map)) {
+			(*id)++;
+			goto again;
+		}
+	}
+	spin_unlock_bh(&map_idr_lock);
+
+	return map;
+}
+
+struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
+{
+	struct bpf_prog *prog;
+
+	spin_lock_bh(&prog_idr_lock);
+again:
+	prog = idr_get_next(&prog_idr, id);
+	if (prog) {
+		prog = bpf_prog_inc_not_zero(prog);
+		if (IS_ERR(prog)) {
+			(*id)++;
+			goto again;
+		}
+	}
+	spin_unlock_bh(&prog_idr_lock);
+
+	return prog;
+}
+
+#define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
+
+struct bpf_prog *bpf_prog_by_id(u32 id)
+{
+	struct bpf_prog *prog;
+
+	if (!id)
+		return ERR_PTR(-ENOENT);
+
+	spin_lock_bh(&prog_idr_lock);
+	prog = idr_find(&prog_idr, id);
+	if (prog)
+		prog = bpf_prog_inc_not_zero(prog);
+	else
+		prog = ERR_PTR(-ENOENT);
+	spin_unlock_bh(&prog_idr_lock);
+	return prog;
+}
+
+static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
+{
+	struct bpf_prog *prog;
+	u32 id = attr->prog_id;
+	int fd;
+
+	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
+		return -EINVAL;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	prog = bpf_prog_by_id(id);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	fd = bpf_prog_new_fd(prog);
+	if (fd < 0)
+		bpf_prog_put(prog);
+
+	return fd;
+}
+
+#define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
+
+static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
+{
+	struct bpf_map *map;
+	u32 id = attr->map_id;
+	int f_flags;
+	int fd;
+
+	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
+	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
+		return -EINVAL;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	f_flags = bpf_get_file_flag(attr->open_flags);
+	if (f_flags < 0)
+		return f_flags;
+
+	spin_lock_bh(&map_idr_lock);
+	map = idr_find(&map_idr, id);
+	if (map)
+		map = __bpf_map_inc_not_zero(map, true);
+	else
+		map = ERR_PTR(-ENOENT);
+	spin_unlock_bh(&map_idr_lock);
+
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	fd = bpf_map_new_fd(map, f_flags);
+	if (fd < 0)
+		bpf_map_put_with_uref(map);
+
+	return fd;
+}
+
+static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
+					      unsigned long addr, u32 *off,
+					      u32 *type)
+{
+	const struct bpf_map *map;
+	int i;
+
+	mutex_lock(&prog->aux->used_maps_mutex);
+	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
+		map = prog->aux->used_maps[i];
+		if (map == (void *)addr) {
+			*type = BPF_PSEUDO_MAP_FD;
+			goto out;
+		}
+		if (!map->ops->map_direct_value_meta)
+			continue;
+		if (!map->ops->map_direct_value_meta(map, addr, off)) {
+			*type = BPF_PSEUDO_MAP_VALUE;
+			goto out;
+		}
+	}
+	map = NULL;
+
+out:
+	mutex_unlock(&prog->aux->used_maps_mutex);
+	return map;
+}
+
+static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
+					      const struct cred *f_cred)
+{
+	const struct bpf_map *map;
+	struct bpf_insn *insns;
+	u32 off, type;
+	u64 imm;
+	u8 code;
+	int i;
+
+	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
+			GFP_USER);
+	if (!insns)
+		return insns;
+
+	for (i = 0; i < prog->len; i++) {
+		code = insns[i].code;
+
+		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
+			insns[i].code = BPF_JMP | BPF_CALL;
+			insns[i].imm = BPF_FUNC_tail_call;
+			/* fall-through */
+		}
+		if (code == (BPF_JMP | BPF_CALL) ||
+		    code == (BPF_JMP | BPF_CALL_ARGS)) {
+			if (code == (BPF_JMP | BPF_CALL_ARGS))
+				insns[i].code = BPF_JMP | BPF_CALL;
+			if (!bpf_dump_raw_ok(f_cred))
+				insns[i].imm = 0;
+			continue;
+		}
+		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
+			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
+			continue;
+		}
+
+		if (code != (BPF_LD | BPF_IMM | BPF_DW))
+			continue;
+
+		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
+		map = bpf_map_from_imm(prog, imm, &off, &type);
+		if (map) {
+			insns[i].src_reg = type;
+			insns[i].imm = map->id;
+			insns[i + 1].imm = off;
+			continue;
+		}
+	}
+
+	return insns;
+}
+
+static int set_info_rec_size(struct bpf_prog_info *info)
+{
+	/*
+	 * Ensure info.*_rec_size is the same as kernel expected size
+	 *
+	 * or
+	 *
+	 * Only allow zero *_rec_size if both _rec_size and _cnt are
+	 * zero.  In this case, the kernel will set the expected
+	 * _rec_size back to the info.
+	 */
+
+	if ((info->nr_func_info || info->func_info_rec_size) &&
+	    info->func_info_rec_size != sizeof(struct bpf_func_info))
+		return -EINVAL;
+
+	if ((info->nr_line_info || info->line_info_rec_size) &&
+	    info->line_info_rec_size != sizeof(struct bpf_line_info))
+		return -EINVAL;
+
+	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
+	    info->jited_line_info_rec_size != sizeof(__u64))
+		return -EINVAL;
+
+	info->func_info_rec_size = sizeof(struct bpf_func_info);
+	info->line_info_rec_size = sizeof(struct bpf_line_info);
+	info->jited_line_info_rec_size = sizeof(__u64);
+
+	return 0;
+}
+
+static int bpf_prog_get_info_by_fd(struct file *file,
+				   struct bpf_prog *prog,
+				   const union bpf_attr *attr,
+				   union bpf_attr __user *uattr)
+{
+	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
+	struct bpf_prog_info info;
+	u32 info_len = attr->info.info_len;
+	struct bpf_prog_stats stats;
+	char __user *uinsns;
+	u32 ulen;
+	int err;
+
+	err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
+	if (err)
+		return err;
+	info_len = min_t(u32, sizeof(info), info_len);
+
+	memset(&info, 0, sizeof(info));
+	if (copy_from_user(&info, uinfo, info_len))
+		return -EFAULT;
+
+	info.type = prog->type;
+	info.id = prog->aux->id;
+	info.load_time = prog->aux->load_time;
+	info.created_by_uid = from_kuid_munged(current_user_ns(),
+					       prog->aux->user->uid);
+	info.gpl_compatible = prog->gpl_compatible;
+
+	memcpy(info.tag, prog->tag, sizeof(prog->tag));
+	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
+
+	mutex_lock(&prog->aux->used_maps_mutex);
+	ulen = info.nr_map_ids;
+	info.nr_map_ids = prog->aux->used_map_cnt;
+	ulen = min_t(u32, info.nr_map_ids, ulen);
+	if (ulen) {
+		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
+		u32 i;
+
+		for (i = 0; i < ulen; i++)
+			if (put_user(prog->aux->used_maps[i]->id,
+				     &user_map_ids[i])) {
+				mutex_unlock(&prog->aux->used_maps_mutex);
+				return -EFAULT;
+			}
+	}
+	mutex_unlock(&prog->aux->used_maps_mutex);
+
+	err = set_info_rec_size(&info);
+	if (err)
+		return err;
+
+	bpf_prog_get_stats(prog, &stats);
+	info.run_time_ns = stats.nsecs;
+	info.run_cnt = stats.cnt;
+
+	if (!bpf_capable()) {
+		info.jited_prog_len = 0;
+		info.xlated_prog_len = 0;
+		info.nr_jited_ksyms = 0;
+		info.nr_jited_func_lens = 0;
+		info.nr_func_info = 0;
+		info.nr_line_info = 0;
+		info.nr_jited_line_info = 0;
+		goto done;
+	}
+
+	ulen = info.xlated_prog_len;
+	info.xlated_prog_len = bpf_prog_insn_size(prog);
+	if (info.xlated_prog_len && ulen) {
+		struct bpf_insn *insns_sanitized;
+		bool fault;
+
+		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
+			info.xlated_prog_insns = 0;
+			goto done;
+		}
+		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
+		if (!insns_sanitized)
+			return -ENOMEM;
+		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
+		ulen = min_t(u32, info.xlated_prog_len, ulen);
+		fault = copy_to_user(uinsns, insns_sanitized, ulen);
+		kfree(insns_sanitized);
+		if (fault)
+			return -EFAULT;
+	}
+
+	if (bpf_prog_is_dev_bound(prog->aux)) {
+		err = bpf_prog_offload_info_fill(&info, prog);
+		if (err)
+			return err;
+		goto done;
+	}
+
+	/* NOTE: the following code is supposed to be skipped for offload.
+	 * bpf_prog_offload_info_fill() is the place to fill similar fields
+	 * for offload.
+	 */
+	ulen = info.jited_prog_len;
+	if (prog->aux->func_cnt) {
+		u32 i;
+
+		info.jited_prog_len = 0;
+		for (i = 0; i < prog->aux->func_cnt; i++)
+			info.jited_prog_len += prog->aux->func[i]->jited_len;
+	} else {
+		info.jited_prog_len = prog->jited_len;
+	}
+
+	if (info.jited_prog_len && ulen) {
+		if (bpf_dump_raw_ok(file->f_cred)) {
+			uinsns = u64_to_user_ptr(info.jited_prog_insns);
+			ulen = min_t(u32, info.jited_prog_len, ulen);
+
+			/* for multi-function programs, copy the JITed
+			 * instructions for all the functions
+			 */
+			if (prog->aux->func_cnt) {
+				u32 len, free, i;
+				u8 *img;
+
+				free = ulen;
+				for (i = 0; i < prog->aux->func_cnt; i++) {
+					len = prog->aux->func[i]->jited_len;
+					len = min_t(u32, len, free);
+					img = (u8 *) prog->aux->func[i]->bpf_func;
+					if (copy_to_user(uinsns, img, len))
+						return -EFAULT;
+					uinsns += len;
+					free -= len;
+					if (!free)
+						break;
+				}
+			} else {
+				if (copy_to_user(uinsns, prog->bpf_func, ulen))
+					return -EFAULT;
+			}
+		} else {
+			info.jited_prog_insns = 0;
+		}
+	}
+
+	ulen = info.nr_jited_ksyms;
+	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
+	if (ulen) {
+		if (bpf_dump_raw_ok(file->f_cred)) {
+			unsigned long ksym_addr;
+			u64 __user *user_ksyms;
+			u32 i;
+
+			/* copy the address of the kernel symbol
+			 * corresponding to each function
+			 */
+			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
+			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
+			if (prog->aux->func_cnt) {
+				for (i = 0; i < ulen; i++) {
+					ksym_addr = (unsigned long)
+						prog->aux->func[i]->bpf_func;
+					if (put_user((u64) ksym_addr,
+						     &user_ksyms[i]))
+						return -EFAULT;
+				}
+			} else {
+				ksym_addr = (unsigned long) prog->bpf_func;
+				if (put_user((u64) ksym_addr, &user_ksyms[0]))
+					return -EFAULT;
+			}
+		} else {
+			info.jited_ksyms = 0;
+		}
+	}
+
+	ulen = info.nr_jited_func_lens;
+	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
+	if (ulen) {
+		if (bpf_dump_raw_ok(file->f_cred)) {
+			u32 __user *user_lens;
+			u32 func_len, i;
+
+			/* copy the JITed image lengths for each function */
+			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
+			user_lens = u64_to_user_ptr(info.jited_func_lens);
+			if (prog->aux->func_cnt) {
+				for (i = 0; i < ulen; i++) {
+					func_len =
+						prog->aux->func[i]->jited_len;
+					if (put_user(func_len, &user_lens[i]))
+						return -EFAULT;
+				}
+			} else {
+				func_len = prog->jited_len;
+				if (put_user(func_len, &user_lens[0]))
+					return -EFAULT;
+			}
+		} else {
+			info.jited_func_lens = 0;
+		}
+	}
+
+	if (prog->aux->btf)
+		info.btf_id = btf_id(prog->aux->btf);
+
+	ulen = info.nr_func_info;
+	info.nr_func_info = prog->aux->func_info_cnt;
+	if (info.nr_func_info && ulen) {
+		char __user *user_finfo;
+
+		user_finfo = u64_to_user_ptr(info.func_info);
+		ulen = min_t(u32, info.nr_func_info, ulen);
+		if (copy_to_user(user_finfo, prog->aux->func_info,
+				 info.func_info_rec_size * ulen))
+			return -EFAULT;
+	}
+
+	ulen = info.nr_line_info;
+	info.nr_line_info = prog->aux->nr_linfo;
+	if (info.nr_line_info && ulen) {
+		__u8 __user *user_linfo;
+
+		user_linfo = u64_to_user_ptr(info.line_info);
+		ulen = min_t(u32, info.nr_line_info, ulen);
+		if (copy_to_user(user_linfo, prog->aux->linfo,
+				 info.line_info_rec_size * ulen))
+			return -EFAULT;
+	}
+
+	ulen = info.nr_jited_line_info;
+	if (prog->aux->jited_linfo)
+		info.nr_jited_line_info = prog->aux->nr_linfo;
+	else
+		info.nr_jited_line_info = 0;
+	if (info.nr_jited_line_info && ulen) {
+		if (bpf_dump_raw_ok(file->f_cred)) {
+			__u64 __user *user_linfo;
+			u32 i;
+
+			user_linfo = u64_to_user_ptr(info.jited_line_info);
+			ulen = min_t(u32, info.nr_jited_line_info, ulen);
+			for (i = 0; i < ulen; i++) {
+				if (put_user((__u64)(long)prog->aux->jited_linfo[i],
+					     &user_linfo[i]))
+					return -EFAULT;
+			}
+		} else {
+			info.jited_line_info = 0;
+		}
+	}
+
+	ulen = info.nr_prog_tags;
+	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
+	if (ulen) {
+		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
+		u32 i;
+
+		user_prog_tags = u64_to_user_ptr(info.prog_tags);
+		ulen = min_t(u32, info.nr_prog_tags, ulen);
+		if (prog->aux->func_cnt) {
+			for (i = 0; i < ulen; i++) {
+				if (copy_to_user(user_prog_tags[i],
+						 prog->aux->func[i]->tag,
+						 BPF_TAG_SIZE))
+					return -EFAULT;
+			}
+		} else {
+			if (copy_to_user(user_prog_tags[0],
+					 prog->tag, BPF_TAG_SIZE))
+				return -EFAULT;
+		}
+	}
+
+done:
+	if (copy_to_user(uinfo, &info, info_len) ||
+	    put_user(info_len, &uattr->info.info_len))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int bpf_map_get_info_by_fd(struct file *file,
+				  struct bpf_map *map,
+				  const union bpf_attr *attr,
+				  union bpf_attr __user *uattr)
+{
+	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
+	struct bpf_map_info info;
+	u32 info_len = attr->info.info_len;
+	int err;
+
+	err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
+	if (err)
+		return err;
+	info_len = min_t(u32, sizeof(info), info_len);
+
+	memset(&info, 0, sizeof(info));
+	info.type = map->map_type;
+	info.id = map->id;
+	info.key_size = map->key_size;
+	info.value_size = map->value_size;
+	info.max_entries = map->max_entries;
+	info.map_flags = map->map_flags;
+	memcpy(info.name, map->name, sizeof(map->name));
+
+	if (map->btf) {
+		info.btf_id = btf_id(map->btf);
+		info.btf_key_type_id = map->btf_key_type_id;
+		info.btf_value_type_id = map->btf_value_type_id;
+	}
+	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
+
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_info_fill(&info, map);
+		if (err)
+			return err;
+	}
+
+	if (copy_to_user(uinfo, &info, info_len) ||
+	    put_user(info_len, &uattr->info.info_len))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int bpf_btf_get_info_by_fd(struct file *file,
+				  struct btf *btf,
+				  const union bpf_attr *attr,
+				  union bpf_attr __user *uattr)
+{
+	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
+	u32 info_len = attr->info.info_len;
+	int err;
+
+	err = bpf_check_uarg_tail_zero(uinfo, sizeof(*uinfo), info_len);
+	if (err)
+		return err;
+
+	return btf_get_info_by_fd(btf, attr, uattr);
+}
+
+static int bpf_link_get_info_by_fd(struct file *file,
+				  struct bpf_link *link,
+				  const union bpf_attr *attr,
+				  union bpf_attr __user *uattr)
+{
+	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
+	struct bpf_link_info info;
+	u32 info_len = attr->info.info_len;
+	int err;
+
+	err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
+	if (err)
+		return err;
+	info_len = min_t(u32, sizeof(info), info_len);
+
+	memset(&info, 0, sizeof(info));
+	if (copy_from_user(&info, uinfo, info_len))
+		return -EFAULT;
+
+	info.type = link->type;
+	info.id = link->id;
+	info.prog_id = link->prog->aux->id;
+
+	if (link->ops->fill_link_info) {
+		err = link->ops->fill_link_info(link, &info);
+		if (err)
+			return err;
+	}
+
+	if (copy_to_user(uinfo, &info, info_len) ||
+	    put_user(info_len, &uattr->info.info_len))
+		return -EFAULT;
+
+	return 0;
+}
+
+
+#define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
+
+static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
+				  union bpf_attr __user *uattr)
+{
+	int ufd = attr->info.bpf_fd;
+	struct fd f;
+	int err;
+
+	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
+		return -EINVAL;
+
+	f = fdget(ufd);
+	if (!f.file)
+		return -EBADFD;
+
+	if (f.file->f_op == &bpf_prog_fops)
+		err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
+					      uattr);
+	else if (f.file->f_op == &bpf_map_fops)
+		err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
+					     uattr);
+	else if (f.file->f_op == &btf_fops)
+		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
+	else if (f.file->f_op == &bpf_link_fops)
+		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
+					      attr, uattr);
+	else
+		err = -EINVAL;
+
+	fdput(f);
+	return err;
+}
+
+#define BPF_BTF_LOAD_LAST_FIELD btf_log_level
+
+static int bpf_btf_load(const union bpf_attr *attr)
+{
+	if (CHECK_ATTR(BPF_BTF_LOAD))
+		return -EINVAL;
+
+	if (!bpf_capable())
+		return -EPERM;
+
+	return btf_new_fd(attr);
+}
+
+#define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
+
+static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
+{
+	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
+		return -EINVAL;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	return btf_get_fd_by_id(attr->btf_id);
+}
+
+static int bpf_task_fd_query_copy(const union bpf_attr *attr,
+				    union bpf_attr __user *uattr,
+				    u32 prog_id, u32 fd_type,
+				    const char *buf, u64 probe_offset,
+				    u64 probe_addr)
+{
+	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
+	u32 len = buf ? strlen(buf) : 0, input_len;
+	int err = 0;
+
+	if (put_user(len, &uattr->task_fd_query.buf_len))
+		return -EFAULT;
+	input_len = attr->task_fd_query.buf_len;
+	if (input_len && ubuf) {
+		if (!len) {
+			/* nothing to copy, just make ubuf NULL terminated */
+			char zero = '\0';
+
+			if (put_user(zero, ubuf))
+				return -EFAULT;
+		} else if (input_len >= len + 1) {
+			/* ubuf can hold the string with NULL terminator */
+			if (copy_to_user(ubuf, buf, len + 1))
+				return -EFAULT;
+		} else {
+			/* ubuf cannot hold the string with NULL terminator,
+			 * do a partial copy with NULL terminator.
+			 */
+			char zero = '\0';
+
+			err = -ENOSPC;
+			if (copy_to_user(ubuf, buf, input_len - 1))
+				return -EFAULT;
+			if (put_user(zero, ubuf + input_len - 1))
+				return -EFAULT;
+		}
+	}
+
+	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
+	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
+	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
+	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
+		return -EFAULT;
+
+	return err;
+}
+
+#define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
+
+static int bpf_task_fd_query(const union bpf_attr *attr,
+			     union bpf_attr __user *uattr)
+{
+	pid_t pid = attr->task_fd_query.pid;
+	u32 fd = attr->task_fd_query.fd;
+	const struct perf_event *event;
+	struct files_struct *files;
+	struct task_struct *task;
+	struct file *file;
+	int err;
+
+	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
+		return -EINVAL;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (attr->task_fd_query.flags != 0)
+		return -EINVAL;
+
+	rcu_read_lock();
+	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
+	rcu_read_unlock();
+	if (!task)
+		return -ENOENT;
+
+	files = get_files_struct(task);
+	put_task_struct(task);
+	if (!files)
+		return -ENOENT;
+
+	err = 0;
+	spin_lock(&files->file_lock);
+	file = fcheck_files(files, fd);
+	if (!file)
+		err = -EBADF;
+	else
+		get_file(file);
+	spin_unlock(&files->file_lock);
+	put_files_struct(files);
+
+	if (err)
+		goto out;
+
+	if (file->f_op == &bpf_link_fops) {
+		struct bpf_link *link = file->private_data;
+
+		if (link->ops == &bpf_raw_tp_link_lops) {
+			struct bpf_raw_tp_link *raw_tp =
+				container_of(link, struct bpf_raw_tp_link, link);
+			struct bpf_raw_event_map *btp = raw_tp->btp;
+
+			err = bpf_task_fd_query_copy(attr, uattr,
+						     raw_tp->link.prog->aux->id,
+						     BPF_FD_TYPE_RAW_TRACEPOINT,
+						     btp->tp->name, 0, 0);
+			goto put_file;
+		}
+		goto out_not_supp;
+	}
+
+	event = perf_get_event(file);
+	if (!IS_ERR(event)) {
+		u64 probe_offset, probe_addr;
+		u32 prog_id, fd_type;
+		const char *buf;
+
+		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
+					      &buf, &probe_offset,
+					      &probe_addr);
+		if (!err)
+			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
+						     fd_type, buf,
+						     probe_offset,
+						     probe_addr);
+		goto put_file;
+	}
+
+out_not_supp:
+	err = -ENOTSUPP;
+put_file:
+	fput(file);
+out:
+	return err;
+}
+
+#define BPF_MAP_BATCH_LAST_FIELD batch.flags
+
+#define BPF_DO_BATCH(fn)			\
+	do {					\
+		if (!fn) {			\
+			err = -ENOTSUPP;	\
+			goto err_put;		\
+		}				\
+		err = fn(map, attr, uattr);	\
+	} while (0)
+
+static int bpf_map_do_batch(const union bpf_attr *attr,
+			    union bpf_attr __user *uattr,
+			    int cmd)
+{
+	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
+			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
+	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
+	struct bpf_map *map;
+	int err, ufd;
+	struct fd f;
+
+	if (CHECK_ATTR(BPF_MAP_BATCH))
+		return -EINVAL;
+
+	ufd = attr->batch.map_fd;
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+	if (has_write)
+		bpf_map_write_active_inc(map);
+	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
+		err = -EPERM;
+		goto err_put;
+	}
+	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	if (cmd == BPF_MAP_LOOKUP_BATCH)
+		BPF_DO_BATCH(map->ops->map_lookup_batch);
+	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
+		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch);
+	else if (cmd == BPF_MAP_UPDATE_BATCH)
+		BPF_DO_BATCH(map->ops->map_update_batch);
+	else
+		BPF_DO_BATCH(map->ops->map_delete_batch);
+err_put:
+	if (has_write)
+		bpf_map_write_active_dec(map);
+	fdput(f);
+	return err;
+}
+
+static int tracing_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	if (attr->link_create.attach_type != prog->expected_attach_type)
+		return -EINVAL;
+
+	if (prog->expected_attach_type == BPF_TRACE_ITER)
+		return bpf_iter_link_attach(attr, prog);
+	else if (prog->type == BPF_PROG_TYPE_EXT)
+		return bpf_tracing_prog_attach(prog,
+					       attr->link_create.target_fd,
+					       attr->link_create.target_btf_id);
+	return -EINVAL;
+}
+
+#define BPF_LINK_CREATE_LAST_FIELD link_create.iter_info_len
+static int link_create(union bpf_attr *attr)
+{
+	enum bpf_prog_type ptype;
+	struct bpf_prog *prog;
+	int ret;
+
+	if (CHECK_ATTR(BPF_LINK_CREATE))
+		return -EINVAL;
+
+	prog = bpf_prog_get(attr->link_create.prog_fd);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	ret = bpf_prog_attach_check_attach_type(prog,
+						attr->link_create.attach_type);
+	if (ret)
+		goto out;
+
+	if (prog->type == BPF_PROG_TYPE_EXT) {
+		ret = tracing_bpf_link_attach(attr, prog);
+		goto out;
+	}
+
+	ptype = attach_type_to_prog_type(attr->link_create.attach_type);
+	if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	switch (ptype) {
+	case BPF_PROG_TYPE_CGROUP_SKB:
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+	case BPF_PROG_TYPE_SOCK_OPS:
+	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+		ret = cgroup_bpf_link_attach(attr, prog);
+		break;
+	case BPF_PROG_TYPE_TRACING:
+		ret = tracing_bpf_link_attach(attr, prog);
+		break;
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+	case BPF_PROG_TYPE_SK_LOOKUP:
+		ret = netns_bpf_link_create(attr, prog);
+		break;
+#ifdef CONFIG_NET
+	case BPF_PROG_TYPE_XDP:
+		ret = bpf_xdp_link_attach(attr, prog);
+		break;
+#endif
+	default:
+		ret = -EINVAL;
+	}
+
+out:
+	if (ret < 0)
+		bpf_prog_put(prog);
+	return ret;
+}
+
+#define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
+
+static int link_update(union bpf_attr *attr)
+{
+	struct bpf_prog *old_prog = NULL, *new_prog;
+	struct bpf_link *link;
+	u32 flags;
+	int ret;
+
+	if (CHECK_ATTR(BPF_LINK_UPDATE))
+		return -EINVAL;
+
+	flags = attr->link_update.flags;
+	if (flags & ~BPF_F_REPLACE)
+		return -EINVAL;
+
+	link = bpf_link_get_from_fd(attr->link_update.link_fd);
+	if (IS_ERR(link))
+		return PTR_ERR(link);
+
+	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
+	if (IS_ERR(new_prog)) {
+		ret = PTR_ERR(new_prog);
+		goto out_put_link;
+	}
+
+	if (flags & BPF_F_REPLACE) {
+		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
+		if (IS_ERR(old_prog)) {
+			ret = PTR_ERR(old_prog);
+			old_prog = NULL;
+			goto out_put_progs;
+		}
+	} else if (attr->link_update.old_prog_fd) {
+		ret = -EINVAL;
+		goto out_put_progs;
+	}
+
+	if (link->ops->update_prog)
+		ret = link->ops->update_prog(link, new_prog, old_prog);
+	else
+		ret = -EINVAL;
+
+out_put_progs:
+	if (old_prog)
+		bpf_prog_put(old_prog);
+	if (ret)
+		bpf_prog_put(new_prog);
+out_put_link:
+	bpf_link_put(link);
+	return ret;
+}
+
+#define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
+
+static int link_detach(union bpf_attr *attr)
+{
+	struct bpf_link *link;
+	int ret;
+
+	if (CHECK_ATTR(BPF_LINK_DETACH))
+		return -EINVAL;
+
+	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
+	if (IS_ERR(link))
+		return PTR_ERR(link);
+
+	if (link->ops->detach)
+		ret = link->ops->detach(link);
+	else
+		ret = -EOPNOTSUPP;
+
+	bpf_link_put(link);
+	return ret;
+}
+
+static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
+{
+	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
+}
+
+struct bpf_link *bpf_link_by_id(u32 id)
+{
+	struct bpf_link *link;
+
+	if (!id)
+		return ERR_PTR(-ENOENT);
+
+	spin_lock_bh(&link_idr_lock);
+	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
+	link = idr_find(&link_idr, id);
+	if (link) {
+		if (link->id)
+			link = bpf_link_inc_not_zero(link);
+		else
+			link = ERR_PTR(-EAGAIN);
+	} else {
+		link = ERR_PTR(-ENOENT);
+	}
+	spin_unlock_bh(&link_idr_lock);
+	return link;
+}
+
+#define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
+
+static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
+{
+	struct bpf_link *link;
+	u32 id = attr->link_id;
+	int fd;
+
+	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
+		return -EINVAL;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	link = bpf_link_by_id(id);
+	if (IS_ERR(link))
+		return PTR_ERR(link);
+
+	fd = bpf_link_new_fd(link);
+	if (fd < 0)
+		bpf_link_put(link);
+
+	return fd;
+}
+
+DEFINE_MUTEX(bpf_stats_enabled_mutex);
+
+static int bpf_stats_release(struct inode *inode, struct file *file)
+{
+	mutex_lock(&bpf_stats_enabled_mutex);
+	static_key_slow_dec(&bpf_stats_enabled_key.key);
+	mutex_unlock(&bpf_stats_enabled_mutex);
+	return 0;
+}
+
+static const struct file_operations bpf_stats_fops = {
+	.release = bpf_stats_release,
+};
+
+static int bpf_enable_runtime_stats(void)
+{
+	int fd;
+
+	mutex_lock(&bpf_stats_enabled_mutex);
+
+	/* Set a very high limit to avoid overflow */
+	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
+		mutex_unlock(&bpf_stats_enabled_mutex);
+		return -EBUSY;
+	}
+
+	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
+	if (fd >= 0)
+		static_key_slow_inc(&bpf_stats_enabled_key.key);
+
+	mutex_unlock(&bpf_stats_enabled_mutex);
+	return fd;
+}
+
+#define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
+
+static int bpf_enable_stats(union bpf_attr *attr)
+{
+
+	if (CHECK_ATTR(BPF_ENABLE_STATS))
+		return -EINVAL;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	switch (attr->enable_stats.type) {
+	case BPF_STATS_RUN_TIME:
+		return bpf_enable_runtime_stats();
+	default:
+		break;
+	}
+	return -EINVAL;
+}
+
+#define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
+
+static int bpf_iter_create(union bpf_attr *attr)
+{
+	struct bpf_link *link;
+	int err;
+
+	if (CHECK_ATTR(BPF_ITER_CREATE))
+		return -EINVAL;
+
+	if (attr->iter_create.flags)
+		return -EINVAL;
+
+	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
+	if (IS_ERR(link))
+		return PTR_ERR(link);
+
+	err = bpf_iter_new_fd(link);
+	bpf_link_put(link);
+
+	return err;
+}
+
+#define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
+
+static int bpf_prog_bind_map(union bpf_attr *attr)
+{
+	struct bpf_prog *prog;
+	struct bpf_map *map;
+	struct bpf_map **used_maps_old, **used_maps_new;
+	int i, ret = 0;
+
+	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
+		return -EINVAL;
+
+	if (attr->prog_bind_map.flags)
+		return -EINVAL;
+
+	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
+	if (IS_ERR(prog))
+		return PTR_ERR(prog);
+
+	map = bpf_map_get(attr->prog_bind_map.map_fd);
+	if (IS_ERR(map)) {
+		ret = PTR_ERR(map);
+		goto out_prog_put;
+	}
+
+	mutex_lock(&prog->aux->used_maps_mutex);
+
+	used_maps_old = prog->aux->used_maps;
+
+	for (i = 0; i < prog->aux->used_map_cnt; i++)
+		if (used_maps_old[i] == map) {
+			bpf_map_put(map);
+			goto out_unlock;
+		}
+
+	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
+				      sizeof(used_maps_new[0]),
+				      GFP_KERNEL);
+	if (!used_maps_new) {
+		ret = -ENOMEM;
+		goto out_unlock;
+	}
+
+	memcpy(used_maps_new, used_maps_old,
+	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
+	used_maps_new[prog->aux->used_map_cnt] = map;
+
+	prog->aux->used_map_cnt++;
+	prog->aux->used_maps = used_maps_new;
+
+	kfree(used_maps_old);
+
+out_unlock:
+	mutex_unlock(&prog->aux->used_maps_mutex);
+
+	if (ret)
+		bpf_map_put(map);
+out_prog_put:
+	bpf_prog_put(prog);
+	return ret;
+}
+
+SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
+{
+	union bpf_attr attr;
+	int err;
+
+	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
+		return -EPERM;
+
+	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
+	if (err)
+		return err;
+	size = min_t(u32, size, sizeof(attr));
+
+	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
+	memset(&attr, 0, sizeof(attr));
+	if (copy_from_user(&attr, uattr, size) != 0)
+		return -EFAULT;
+
+	err = security_bpf(cmd, &attr, size);
+	if (err < 0)
+		return err;
+
+	switch (cmd) {
+	case BPF_MAP_CREATE:
+		err = map_create(&attr);
+		break;
+	case BPF_MAP_LOOKUP_ELEM:
+		err = map_lookup_elem(&attr);
+		break;
+	case BPF_MAP_UPDATE_ELEM:
+		err = map_update_elem(&attr);
+		break;
+	case BPF_MAP_DELETE_ELEM:
+		err = map_delete_elem(&attr);
+		break;
+	case BPF_MAP_GET_NEXT_KEY:
+		err = map_get_next_key(&attr);
+		break;
+	case BPF_MAP_FREEZE:
+		err = map_freeze(&attr);
+		break;
+	case BPF_PROG_LOAD:
+		err = bpf_prog_load(&attr, uattr);
+		break;
+	case BPF_OBJ_PIN:
+		err = bpf_obj_pin(&attr);
+		break;
+	case BPF_OBJ_GET:
+		err = bpf_obj_get(&attr);
+		break;
+	case BPF_PROG_ATTACH:
+		err = bpf_prog_attach(&attr);
+		break;
+	case BPF_PROG_DETACH:
+		err = bpf_prog_detach(&attr);
+		break;
+	case BPF_PROG_QUERY:
+		err = bpf_prog_query(&attr, uattr);
+		break;
+	case BPF_PROG_TEST_RUN:
+		err = bpf_prog_test_run(&attr, uattr);
+		break;
+	case BPF_PROG_GET_NEXT_ID:
+		err = bpf_obj_get_next_id(&attr, uattr,
+					  &prog_idr, &prog_idr_lock);
+		break;
+	case BPF_MAP_GET_NEXT_ID:
+		err = bpf_obj_get_next_id(&attr, uattr,
+					  &map_idr, &map_idr_lock);
+		break;
+	case BPF_BTF_GET_NEXT_ID:
+		err = bpf_obj_get_next_id(&attr, uattr,
+					  &btf_idr, &btf_idr_lock);
+		break;
+	case BPF_PROG_GET_FD_BY_ID:
+		err = bpf_prog_get_fd_by_id(&attr);
+		break;
+	case BPF_MAP_GET_FD_BY_ID:
+		err = bpf_map_get_fd_by_id(&attr);
+		break;
+	case BPF_OBJ_GET_INFO_BY_FD:
+		err = bpf_obj_get_info_by_fd(&attr, uattr);
+		break;
+	case BPF_RAW_TRACEPOINT_OPEN:
+		err = bpf_raw_tracepoint_open(&attr);
+		break;
+	case BPF_BTF_LOAD:
+		err = bpf_btf_load(&attr);
+		break;
+	case BPF_BTF_GET_FD_BY_ID:
+		err = bpf_btf_get_fd_by_id(&attr);
+		break;
+	case BPF_TASK_FD_QUERY:
+		err = bpf_task_fd_query(&attr, uattr);
+		break;
+	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
+		err = map_lookup_and_delete_elem(&attr);
+		break;
+	case BPF_MAP_LOOKUP_BATCH:
+		err = bpf_map_do_batch(&attr, uattr, BPF_MAP_LOOKUP_BATCH);
+		break;
+	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
+		err = bpf_map_do_batch(&attr, uattr,
+				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
+		break;
+	case BPF_MAP_UPDATE_BATCH:
+		err = bpf_map_do_batch(&attr, uattr, BPF_MAP_UPDATE_BATCH);
+		break;
+	case BPF_MAP_DELETE_BATCH:
+		err = bpf_map_do_batch(&attr, uattr, BPF_MAP_DELETE_BATCH);
+		break;
+	case BPF_LINK_CREATE:
+		err = link_create(&attr);
+		break;
+	case BPF_LINK_UPDATE:
+		err = link_update(&attr);
+		break;
+	case BPF_LINK_GET_FD_BY_ID:
+		err = bpf_link_get_fd_by_id(&attr);
+		break;
+	case BPF_LINK_GET_NEXT_ID:
+		err = bpf_obj_get_next_id(&attr, uattr,
+					  &link_idr, &link_idr_lock);
+		break;
+	case BPF_ENABLE_STATS:
+		err = bpf_enable_stats(&attr);
+		break;
+	case BPF_ITER_CREATE:
+		err = bpf_iter_create(&attr);
+		break;
+	case BPF_LINK_DETACH:
+		err = link_detach(&attr);
+		break;
+	case BPF_PROG_BIND_MAP:
+		err = bpf_prog_bind_map(&attr);
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+
+	return err;
+}
diff --git a/kernel/bpf/sysfs_btf.c b/kernel/bpf/sysfs_btf.c
new file mode 100644
index 000000000..11b338088
--- /dev/null
+++ b/kernel/bpf/sysfs_btf.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Provide kernel BTF information for introspection and use by eBPF tools.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/init.h>
+#include <linux/sysfs.h>
+
+/* See scripts/link-vmlinux.sh, gen_btf() func for details */
+extern char __weak __start_BTF[];
+extern char __weak __stop_BTF[];
+
+static ssize_t
+btf_vmlinux_read(struct file *file, struct kobject *kobj,
+		 struct bin_attribute *bin_attr,
+		 char *buf, loff_t off, size_t len)
+{
+	memcpy(buf, __start_BTF + off, len);
+	return len;
+}
+
+static struct bin_attribute bin_attr_btf_vmlinux __ro_after_init = {
+	.attr = { .name = "vmlinux", .mode = 0444, },
+	.read = btf_vmlinux_read,
+};
+
+static struct kobject *btf_kobj;
+
+static int __init btf_vmlinux_init(void)
+{
+	bin_attr_btf_vmlinux.size = __stop_BTF - __start_BTF;
+
+	if (!__start_BTF || bin_attr_btf_vmlinux.size == 0)
+		return 0;
+
+	btf_kobj = kobject_create_and_add("btf", kernel_kobj);
+	if (!btf_kobj)
+		return -ENOMEM;
+
+	return sysfs_create_bin_file(btf_kobj, &bin_attr_btf_vmlinux);
+}
+
+subsys_initcall(btf_vmlinux_init);
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
new file mode 100644
index 000000000..f3d3a562a
--- /dev/null
+++ b/kernel/bpf/task_iter.c
@@ -0,0 +1,361 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2020 Facebook */
+
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/pid_namespace.h>
+#include <linux/fs.h>
+#include <linux/fdtable.h>
+#include <linux/filter.h>
+#include <linux/btf_ids.h>
+
+struct bpf_iter_seq_task_common {
+	struct pid_namespace *ns;
+};
+
+struct bpf_iter_seq_task_info {
+	/* The first field must be struct bpf_iter_seq_task_common.
+	 * this is assumed by {init, fini}_seq_pidns() callback functions.
+	 */
+	struct bpf_iter_seq_task_common common;
+	u32 tid;
+};
+
+static struct task_struct *task_seq_get_next(struct pid_namespace *ns,
+					     u32 *tid,
+					     bool skip_if_dup_files)
+{
+	struct task_struct *task = NULL;
+	struct pid *pid;
+
+	rcu_read_lock();
+retry:
+	pid = find_ge_pid(*tid, ns);
+	if (pid) {
+		*tid = pid_nr_ns(pid, ns);
+		task = get_pid_task(pid, PIDTYPE_PID);
+		if (!task) {
+			++*tid;
+			goto retry;
+		} else if (skip_if_dup_files && task->tgid != task->pid &&
+			   task->files == task->group_leader->files) {
+			put_task_struct(task);
+			task = NULL;
+			++*tid;
+			goto retry;
+		}
+	}
+	rcu_read_unlock();
+
+	return task;
+}
+
+static void *task_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_task_info *info = seq->private;
+	struct task_struct *task;
+
+	task = task_seq_get_next(info->common.ns, &info->tid, false);
+	if (!task)
+		return NULL;
+
+	if (*pos == 0)
+		++*pos;
+	return task;
+}
+
+static void *task_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_task_info *info = seq->private;
+	struct task_struct *task;
+
+	++*pos;
+	++info->tid;
+	put_task_struct((struct task_struct *)v);
+	task = task_seq_get_next(info->common.ns, &info->tid, false);
+	if (!task)
+		return NULL;
+
+	return task;
+}
+
+struct bpf_iter__task {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct task_struct *, task);
+};
+
+DEFINE_BPF_ITER_FUNC(task, struct bpf_iter_meta *meta, struct task_struct *task)
+
+static int __task_seq_show(struct seq_file *seq, struct task_struct *task,
+			   bool in_stop)
+{
+	struct bpf_iter_meta meta;
+	struct bpf_iter__task ctx;
+	struct bpf_prog *prog;
+
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, in_stop);
+	if (!prog)
+		return 0;
+
+	meta.seq = seq;
+	ctx.meta = &meta;
+	ctx.task = task;
+	return bpf_iter_run_prog(prog, &ctx);
+}
+
+static int task_seq_show(struct seq_file *seq, void *v)
+{
+	return __task_seq_show(seq, v, false);
+}
+
+static void task_seq_stop(struct seq_file *seq, void *v)
+{
+	if (!v)
+		(void)__task_seq_show(seq, v, true);
+	else
+		put_task_struct((struct task_struct *)v);
+}
+
+static const struct seq_operations task_seq_ops = {
+	.start	= task_seq_start,
+	.next	= task_seq_next,
+	.stop	= task_seq_stop,
+	.show	= task_seq_show,
+};
+
+struct bpf_iter_seq_task_file_info {
+	/* The first field must be struct bpf_iter_seq_task_common.
+	 * this is assumed by {init, fini}_seq_pidns() callback functions.
+	 */
+	struct bpf_iter_seq_task_common common;
+	struct task_struct *task;
+	struct files_struct *files;
+	u32 tid;
+	u32 fd;
+};
+
+static struct file *
+task_file_seq_get_next(struct bpf_iter_seq_task_file_info *info)
+{
+	struct pid_namespace *ns = info->common.ns;
+	u32 curr_tid = info->tid, max_fds;
+	struct files_struct *curr_files;
+	struct task_struct *curr_task;
+	int curr_fd = info->fd;
+
+	/* If this function returns a non-NULL file object,
+	 * it held a reference to the task/files_struct/file.
+	 * Otherwise, it does not hold any reference.
+	 */
+again:
+	if (info->task) {
+		curr_task = info->task;
+		curr_files = info->files;
+		curr_fd = info->fd;
+	} else {
+		curr_task = task_seq_get_next(ns, &curr_tid, true);
+		if (!curr_task) {
+			info->task = NULL;
+			info->files = NULL;
+			info->tid = curr_tid;
+			return NULL;
+		}
+
+		curr_files = get_files_struct(curr_task);
+		if (!curr_files) {
+			put_task_struct(curr_task);
+			curr_tid = curr_tid + 1;
+			info->fd = 0;
+			goto again;
+		}
+
+		info->files = curr_files;
+		info->task = curr_task;
+		if (curr_tid == info->tid) {
+			curr_fd = info->fd;
+		} else {
+			info->tid = curr_tid;
+			curr_fd = 0;
+		}
+	}
+
+	rcu_read_lock();
+	max_fds = files_fdtable(curr_files)->max_fds;
+	for (; curr_fd < max_fds; curr_fd++) {
+		struct file *f;
+
+		f = fcheck_files(curr_files, curr_fd);
+		if (!f)
+			continue;
+		if (!get_file_rcu(f))
+			continue;
+
+		/* set info->fd */
+		info->fd = curr_fd;
+		rcu_read_unlock();
+		return f;
+	}
+
+	/* the current task is done, go to the next task */
+	rcu_read_unlock();
+	put_files_struct(curr_files);
+	put_task_struct(curr_task);
+	info->task = NULL;
+	info->files = NULL;
+	info->fd = 0;
+	curr_tid = ++(info->tid);
+	goto again;
+}
+
+static void *task_file_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct bpf_iter_seq_task_file_info *info = seq->private;
+	struct file *file;
+
+	info->task = NULL;
+	info->files = NULL;
+	file = task_file_seq_get_next(info);
+	if (file && *pos == 0)
+		++*pos;
+
+	return file;
+}
+
+static void *task_file_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct bpf_iter_seq_task_file_info *info = seq->private;
+
+	++*pos;
+	++info->fd;
+	fput((struct file *)v);
+	return task_file_seq_get_next(info);
+}
+
+struct bpf_iter__task_file {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct task_struct *, task);
+	u32 fd __aligned(8);
+	__bpf_md_ptr(struct file *, file);
+};
+
+DEFINE_BPF_ITER_FUNC(task_file, struct bpf_iter_meta *meta,
+		     struct task_struct *task, u32 fd,
+		     struct file *file)
+
+static int __task_file_seq_show(struct seq_file *seq, struct file *file,
+				bool in_stop)
+{
+	struct bpf_iter_seq_task_file_info *info = seq->private;
+	struct bpf_iter__task_file ctx;
+	struct bpf_iter_meta meta;
+	struct bpf_prog *prog;
+
+	meta.seq = seq;
+	prog = bpf_iter_get_info(&meta, in_stop);
+	if (!prog)
+		return 0;
+
+	ctx.meta = &meta;
+	ctx.task = info->task;
+	ctx.fd = info->fd;
+	ctx.file = file;
+	return bpf_iter_run_prog(prog, &ctx);
+}
+
+static int task_file_seq_show(struct seq_file *seq, void *v)
+{
+	return __task_file_seq_show(seq, v, false);
+}
+
+static void task_file_seq_stop(struct seq_file *seq, void *v)
+{
+	struct bpf_iter_seq_task_file_info *info = seq->private;
+
+	if (!v) {
+		(void)__task_file_seq_show(seq, v, true);
+	} else {
+		fput((struct file *)v);
+		put_files_struct(info->files);
+		put_task_struct(info->task);
+		info->files = NULL;
+		info->task = NULL;
+	}
+}
+
+static int init_seq_pidns(void *priv_data, struct bpf_iter_aux_info *aux)
+{
+	struct bpf_iter_seq_task_common *common = priv_data;
+
+	common->ns = get_pid_ns(task_active_pid_ns(current));
+	return 0;
+}
+
+static void fini_seq_pidns(void *priv_data)
+{
+	struct bpf_iter_seq_task_common *common = priv_data;
+
+	put_pid_ns(common->ns);
+}
+
+static const struct seq_operations task_file_seq_ops = {
+	.start	= task_file_seq_start,
+	.next	= task_file_seq_next,
+	.stop	= task_file_seq_stop,
+	.show	= task_file_seq_show,
+};
+
+BTF_ID_LIST(btf_task_file_ids)
+BTF_ID(struct, task_struct)
+BTF_ID(struct, file)
+
+static const struct bpf_iter_seq_info task_seq_info = {
+	.seq_ops		= &task_seq_ops,
+	.init_seq_private	= init_seq_pidns,
+	.fini_seq_private	= fini_seq_pidns,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_task_info),
+};
+
+static struct bpf_iter_reg task_reg_info = {
+	.target			= "task",
+	.ctx_arg_info_size	= 1,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__task, task),
+		  PTR_TO_BTF_ID_OR_NULL },
+	},
+	.seq_info		= &task_seq_info,
+};
+
+static const struct bpf_iter_seq_info task_file_seq_info = {
+	.seq_ops		= &task_file_seq_ops,
+	.init_seq_private	= init_seq_pidns,
+	.fini_seq_private	= fini_seq_pidns,
+	.seq_priv_size		= sizeof(struct bpf_iter_seq_task_file_info),
+};
+
+static struct bpf_iter_reg task_file_reg_info = {
+	.target			= "task_file",
+	.ctx_arg_info_size	= 2,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__task_file, task),
+		  PTR_TO_BTF_ID_OR_NULL },
+		{ offsetof(struct bpf_iter__task_file, file),
+		  PTR_TO_BTF_ID_OR_NULL },
+	},
+	.seq_info		= &task_file_seq_info,
+};
+
+static int __init task_iter_init(void)
+{
+	int ret;
+
+	task_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0];
+	ret = bpf_iter_reg_target(&task_reg_info);
+	if (ret)
+		return ret;
+
+	task_file_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0];
+	task_file_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[1];
+	return bpf_iter_reg_target(&task_file_reg_info);
+}
+late_initcall(task_iter_init);
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
new file mode 100644
index 000000000..ceac5281b
--- /dev/null
+++ b/kernel/bpf/tnum.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* tnum: tracked (or tristate) numbers
+ *
+ * A tnum tracks knowledge about the bits of a value.  Each bit can be either
+ * known (0 or 1), or unknown (x).  Arithmetic operations on tnums will
+ * propagate the unknown bits such that the tnum result represents all the
+ * possible results for possible values of the operands.
+ */
+#include <linux/kernel.h>
+#include <linux/tnum.h>
+
+#define TNUM(_v, _m)	(struct tnum){.value = _v, .mask = _m}
+/* A completely unknown value */
+const struct tnum tnum_unknown = { .value = 0, .mask = -1 };
+
+struct tnum tnum_const(u64 value)
+{
+	return TNUM(value, 0);
+}
+
+struct tnum tnum_range(u64 min, u64 max)
+{
+	u64 chi = min ^ max, delta;
+	u8 bits = fls64(chi);
+
+	/* special case, needed because 1ULL << 64 is undefined */
+	if (bits > 63)
+		return tnum_unknown;
+	/* e.g. if chi = 4, bits = 3, delta = (1<<3) - 1 = 7.
+	 * if chi = 0, bits = 0, delta = (1<<0) - 1 = 0, so we return
+	 *  constant min (since min == max).
+	 */
+	delta = (1ULL << bits) - 1;
+	return TNUM(min & ~delta, delta);
+}
+
+struct tnum tnum_lshift(struct tnum a, u8 shift)
+{
+	return TNUM(a.value << shift, a.mask << shift);
+}
+
+struct tnum tnum_rshift(struct tnum a, u8 shift)
+{
+	return TNUM(a.value >> shift, a.mask >> shift);
+}
+
+struct tnum tnum_arshift(struct tnum a, u8 min_shift, u8 insn_bitness)
+{
+	/* if a.value is negative, arithmetic shifting by minimum shift
+	 * will have larger negative offset compared to more shifting.
+	 * If a.value is nonnegative, arithmetic shifting by minimum shift
+	 * will have larger positive offset compare to more shifting.
+	 */
+	if (insn_bitness == 32)
+		return TNUM((u32)(((s32)a.value) >> min_shift),
+			    (u32)(((s32)a.mask)  >> min_shift));
+	else
+		return TNUM((s64)a.value >> min_shift,
+			    (s64)a.mask  >> min_shift);
+}
+
+struct tnum tnum_add(struct tnum a, struct tnum b)
+{
+	u64 sm, sv, sigma, chi, mu;
+
+	sm = a.mask + b.mask;
+	sv = a.value + b.value;
+	sigma = sm + sv;
+	chi = sigma ^ sv;
+	mu = chi | a.mask | b.mask;
+	return TNUM(sv & ~mu, mu);
+}
+
+struct tnum tnum_sub(struct tnum a, struct tnum b)
+{
+	u64 dv, alpha, beta, chi, mu;
+
+	dv = a.value - b.value;
+	alpha = dv + a.mask;
+	beta = dv - b.mask;
+	chi = alpha ^ beta;
+	mu = chi | a.mask | b.mask;
+	return TNUM(dv & ~mu, mu);
+}
+
+struct tnum tnum_and(struct tnum a, struct tnum b)
+{
+	u64 alpha, beta, v;
+
+	alpha = a.value | a.mask;
+	beta = b.value | b.mask;
+	v = a.value & b.value;
+	return TNUM(v, alpha & beta & ~v);
+}
+
+struct tnum tnum_or(struct tnum a, struct tnum b)
+{
+	u64 v, mu;
+
+	v = a.value | b.value;
+	mu = a.mask | b.mask;
+	return TNUM(v, mu & ~v);
+}
+
+struct tnum tnum_xor(struct tnum a, struct tnum b)
+{
+	u64 v, mu;
+
+	v = a.value ^ b.value;
+	mu = a.mask | b.mask;
+	return TNUM(v & ~mu, mu);
+}
+
+/* half-multiply add: acc += (unknown * mask * value).
+ * An intermediate step in the multiply algorithm.
+ */
+static struct tnum hma(struct tnum acc, u64 value, u64 mask)
+{
+	while (mask) {
+		if (mask & 1)
+			acc = tnum_add(acc, TNUM(0, value));
+		mask >>= 1;
+		value <<= 1;
+	}
+	return acc;
+}
+
+struct tnum tnum_mul(struct tnum a, struct tnum b)
+{
+	struct tnum acc;
+	u64 pi;
+
+	pi = a.value * b.value;
+	acc = hma(TNUM(pi, 0), a.mask, b.mask | b.value);
+	return hma(acc, b.mask, a.value);
+}
+
+/* Note that if a and b disagree - i.e. one has a 'known 1' where the other has
+ * a 'known 0' - this will return a 'known 1' for that bit.
+ */
+struct tnum tnum_intersect(struct tnum a, struct tnum b)
+{
+	u64 v, mu;
+
+	v = a.value | b.value;
+	mu = a.mask & b.mask;
+	return TNUM(v & ~mu, mu);
+}
+
+struct tnum tnum_cast(struct tnum a, u8 size)
+{
+	a.value &= (1ULL << (size * 8)) - 1;
+	a.mask &= (1ULL << (size * 8)) - 1;
+	return a;
+}
+
+bool tnum_is_aligned(struct tnum a, u64 size)
+{
+	if (!size)
+		return true;
+	return !((a.value | a.mask) & (size - 1));
+}
+
+bool tnum_in(struct tnum a, struct tnum b)
+{
+	if (b.mask & ~a.mask)
+		return false;
+	b.value &= ~a.mask;
+	return a.value == b.value;
+}
+
+int tnum_strn(char *str, size_t size, struct tnum a)
+{
+	return snprintf(str, size, "(%#llx; %#llx)", a.value, a.mask);
+}
+EXPORT_SYMBOL_GPL(tnum_strn);
+
+int tnum_sbin(char *str, size_t size, struct tnum a)
+{
+	size_t n;
+
+	for (n = 64; n; n--) {
+		if (n < size) {
+			if (a.mask & 1)
+				str[n - 1] = 'x';
+			else if (a.value & 1)
+				str[n - 1] = '1';
+			else
+				str[n - 1] = '0';
+		}
+		a.mask >>= 1;
+		a.value >>= 1;
+	}
+	str[min(size - 1, (size_t)64)] = 0;
+	return 64;
+}
+
+struct tnum tnum_subreg(struct tnum a)
+{
+	return tnum_cast(a, 4);
+}
+
+struct tnum tnum_clear_subreg(struct tnum a)
+{
+	return tnum_lshift(tnum_rshift(a, 32), 32);
+}
+
+struct tnum tnum_const_subreg(struct tnum a, u32 value)
+{
+	return tnum_or(tnum_clear_subreg(a), tnum_const(value));
+}
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
new file mode 100644
index 000000000..87becf77c
--- /dev/null
+++ b/kernel/bpf/trampoline.c
@@ -0,0 +1,577 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2019 Facebook */
+#include <linux/hash.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/ftrace.h>
+#include <linux/rbtree_latch.h>
+#include <linux/perf_event.h>
+#include <linux/btf.h>
+#include <linux/rcupdate_trace.h>
+#include <linux/rcupdate_wait.h>
+
+/* dummy _ops. The verifier will operate on target program's ops. */
+const struct bpf_verifier_ops bpf_extension_verifier_ops = {
+};
+const struct bpf_prog_ops bpf_extension_prog_ops = {
+};
+
+/* btf_vmlinux has ~22k attachable functions. 1k htab is enough. */
+#define TRAMPOLINE_HASH_BITS 10
+#define TRAMPOLINE_TABLE_SIZE (1 << TRAMPOLINE_HASH_BITS)
+
+static struct hlist_head trampoline_table[TRAMPOLINE_TABLE_SIZE];
+
+/* serializes access to trampoline_table */
+static DEFINE_MUTEX(trampoline_mutex);
+
+void *bpf_jit_alloc_exec_page(void)
+{
+	void *image;
+
+	image = bpf_jit_alloc_exec(PAGE_SIZE);
+	if (!image)
+		return NULL;
+
+	set_vm_flush_reset_perms(image);
+	/* Keep image as writeable. The alternative is to keep flipping ro/rw
+	 * everytime new program is attached or detached.
+	 */
+	set_memory_x((long)image, 1);
+	return image;
+}
+
+void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym)
+{
+	ksym->start = (unsigned long) data;
+	ksym->end = ksym->start + PAGE_SIZE;
+	bpf_ksym_add(ksym);
+	perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,
+			   PAGE_SIZE, false, ksym->name);
+}
+
+void bpf_image_ksym_del(struct bpf_ksym *ksym)
+{
+	bpf_ksym_del(ksym);
+	perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,
+			   PAGE_SIZE, true, ksym->name);
+}
+
+static struct bpf_trampoline *bpf_trampoline_lookup(u64 key)
+{
+	struct bpf_trampoline *tr;
+	struct hlist_head *head;
+	int i;
+
+	mutex_lock(&trampoline_mutex);
+	head = &trampoline_table[hash_64(key, TRAMPOLINE_HASH_BITS)];
+	hlist_for_each_entry(tr, head, hlist) {
+		if (tr->key == key) {
+			refcount_inc(&tr->refcnt);
+			goto out;
+		}
+	}
+	tr = kzalloc(sizeof(*tr), GFP_KERNEL);
+	if (!tr)
+		goto out;
+
+	tr->key = key;
+	INIT_HLIST_NODE(&tr->hlist);
+	hlist_add_head(&tr->hlist, head);
+	refcount_set(&tr->refcnt, 1);
+	mutex_init(&tr->mutex);
+	for (i = 0; i < BPF_TRAMP_MAX; i++)
+		INIT_HLIST_HEAD(&tr->progs_hlist[i]);
+out:
+	mutex_unlock(&trampoline_mutex);
+	return tr;
+}
+
+static int is_ftrace_location(void *ip)
+{
+	long addr;
+
+	addr = ftrace_location((long)ip);
+	if (!addr)
+		return 0;
+	if (WARN_ON_ONCE(addr != (long)ip))
+		return -EFAULT;
+	return 1;
+}
+
+static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr)
+{
+	void *ip = tr->func.addr;
+	int ret;
+
+	if (tr->func.ftrace_managed)
+		ret = unregister_ftrace_direct((long)ip, (long)old_addr);
+	else
+		ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, old_addr, NULL);
+	return ret;
+}
+
+static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_addr)
+{
+	void *ip = tr->func.addr;
+	int ret;
+
+	if (tr->func.ftrace_managed)
+		ret = modify_ftrace_direct((long)ip, (long)old_addr, (long)new_addr);
+	else
+		ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, old_addr, new_addr);
+	return ret;
+}
+
+/* first time registering */
+static int register_fentry(struct bpf_trampoline *tr, void *new_addr)
+{
+	void *ip = tr->func.addr;
+	int ret;
+
+	ret = is_ftrace_location(ip);
+	if (ret < 0)
+		return ret;
+	tr->func.ftrace_managed = ret;
+
+	if (tr->func.ftrace_managed)
+		ret = register_ftrace_direct((long)ip, (long)new_addr);
+	else
+		ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, NULL, new_addr);
+	return ret;
+}
+
+static struct bpf_tramp_progs *
+bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total)
+{
+	const struct bpf_prog_aux *aux;
+	struct bpf_tramp_progs *tprogs;
+	struct bpf_prog **progs;
+	int kind;
+
+	*total = 0;
+	tprogs = kcalloc(BPF_TRAMP_MAX, sizeof(*tprogs), GFP_KERNEL);
+	if (!tprogs)
+		return ERR_PTR(-ENOMEM);
+
+	for (kind = 0; kind < BPF_TRAMP_MAX; kind++) {
+		tprogs[kind].nr_progs = tr->progs_cnt[kind];
+		*total += tr->progs_cnt[kind];
+		progs = tprogs[kind].progs;
+
+		hlist_for_each_entry(aux, &tr->progs_hlist[kind], tramp_hlist)
+			*progs++ = aux->prog;
+	}
+	return tprogs;
+}
+
+static void __bpf_tramp_image_put_deferred(struct work_struct *work)
+{
+	struct bpf_tramp_image *im;
+
+	im = container_of(work, struct bpf_tramp_image, work);
+	bpf_image_ksym_del(&im->ksym);
+	bpf_jit_free_exec(im->image);
+	bpf_jit_uncharge_modmem(1);
+	percpu_ref_exit(&im->pcref);
+	kfree_rcu(im, rcu);
+}
+
+/* callback, fexit step 3 or fentry step 2 */
+static void __bpf_tramp_image_put_rcu(struct rcu_head *rcu)
+{
+	struct bpf_tramp_image *im;
+
+	im = container_of(rcu, struct bpf_tramp_image, rcu);
+	INIT_WORK(&im->work, __bpf_tramp_image_put_deferred);
+	schedule_work(&im->work);
+}
+
+/* callback, fexit step 2. Called after percpu_ref_kill confirms. */
+static void __bpf_tramp_image_release(struct percpu_ref *pcref)
+{
+	struct bpf_tramp_image *im;
+
+	im = container_of(pcref, struct bpf_tramp_image, pcref);
+	call_rcu_tasks(&im->rcu, __bpf_tramp_image_put_rcu);
+}
+
+/* callback, fexit or fentry step 1 */
+static void __bpf_tramp_image_put_rcu_tasks(struct rcu_head *rcu)
+{
+	struct bpf_tramp_image *im;
+
+	im = container_of(rcu, struct bpf_tramp_image, rcu);
+	if (im->ip_after_call)
+		/* the case of fmod_ret/fexit trampoline and CONFIG_PREEMPTION=y */
+		percpu_ref_kill(&im->pcref);
+	else
+		/* the case of fentry trampoline */
+		call_rcu_tasks(&im->rcu, __bpf_tramp_image_put_rcu);
+}
+
+static void bpf_tramp_image_put(struct bpf_tramp_image *im)
+{
+	/* The trampoline image that calls original function is using:
+	 * rcu_read_lock_trace to protect sleepable bpf progs
+	 * rcu_read_lock to protect normal bpf progs
+	 * percpu_ref to protect trampoline itself
+	 * rcu tasks to protect trampoline asm not covered by percpu_ref
+	 * (which are few asm insns before __bpf_tramp_enter and
+	 *  after __bpf_tramp_exit)
+	 *
+	 * The trampoline is unreachable before bpf_tramp_image_put().
+	 *
+	 * First, patch the trampoline to avoid calling into fexit progs.
+	 * The progs will be freed even if the original function is still
+	 * executing or sleeping.
+	 * In case of CONFIG_PREEMPT=y use call_rcu_tasks() to wait on
+	 * first few asm instructions to execute and call into
+	 * __bpf_tramp_enter->percpu_ref_get.
+	 * Then use percpu_ref_kill to wait for the trampoline and the original
+	 * function to finish.
+	 * Then use call_rcu_tasks() to make sure few asm insns in
+	 * the trampoline epilogue are done as well.
+	 *
+	 * In !PREEMPT case the task that got interrupted in the first asm
+	 * insns won't go through an RCU quiescent state which the
+	 * percpu_ref_kill will be waiting for. Hence the first
+	 * call_rcu_tasks() is not necessary.
+	 */
+	if (im->ip_after_call) {
+		int err = bpf_arch_text_poke(im->ip_after_call, BPF_MOD_JUMP,
+					     NULL, im->ip_epilogue);
+		WARN_ON(err);
+		if (IS_ENABLED(CONFIG_PREEMPTION))
+			call_rcu_tasks(&im->rcu, __bpf_tramp_image_put_rcu_tasks);
+		else
+			percpu_ref_kill(&im->pcref);
+		return;
+	}
+
+	/* The trampoline without fexit and fmod_ret progs doesn't call original
+	 * function and doesn't use percpu_ref.
+	 * Use call_rcu_tasks_trace() to wait for sleepable progs to finish.
+	 * Then use call_rcu_tasks() to wait for the rest of trampoline asm
+	 * and normal progs.
+	 */
+	call_rcu_tasks_trace(&im->rcu, __bpf_tramp_image_put_rcu_tasks);
+}
+
+static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key, u32 idx)
+{
+	struct bpf_tramp_image *im;
+	struct bpf_ksym *ksym;
+	void *image;
+	int err = -ENOMEM;
+
+	im = kzalloc(sizeof(*im), GFP_KERNEL);
+	if (!im)
+		goto out;
+
+	err = bpf_jit_charge_modmem(1);
+	if (err)
+		goto out_free_im;
+
+	err = -ENOMEM;
+	im->image = image = bpf_jit_alloc_exec_page();
+	if (!image)
+		goto out_uncharge;
+
+	err = percpu_ref_init(&im->pcref, __bpf_tramp_image_release, 0, GFP_KERNEL);
+	if (err)
+		goto out_free_image;
+
+	ksym = &im->ksym;
+	INIT_LIST_HEAD_RCU(&ksym->lnode);
+	snprintf(ksym->name, KSYM_NAME_LEN, "bpf_trampoline_%llu_%u", key, idx);
+	bpf_image_ksym_add(image, ksym);
+	return im;
+
+out_free_image:
+	bpf_jit_free_exec(im->image);
+out_uncharge:
+	bpf_jit_uncharge_modmem(1);
+out_free_im:
+	kfree(im);
+out:
+	return ERR_PTR(err);
+}
+
+static int bpf_trampoline_update(struct bpf_trampoline *tr)
+{
+	struct bpf_tramp_image *im;
+	struct bpf_tramp_progs *tprogs;
+	u32 flags = BPF_TRAMP_F_RESTORE_REGS;
+	int err, total;
+
+	tprogs = bpf_trampoline_get_progs(tr, &total);
+	if (IS_ERR(tprogs))
+		return PTR_ERR(tprogs);
+
+	if (total == 0) {
+		err = unregister_fentry(tr, tr->cur_image->image);
+		bpf_tramp_image_put(tr->cur_image);
+		tr->cur_image = NULL;
+		tr->selector = 0;
+		goto out;
+	}
+
+	im = bpf_tramp_image_alloc(tr->key, tr->selector);
+	if (IS_ERR(im)) {
+		err = PTR_ERR(im);
+		goto out;
+	}
+
+	if (tprogs[BPF_TRAMP_FEXIT].nr_progs ||
+	    tprogs[BPF_TRAMP_MODIFY_RETURN].nr_progs)
+		flags = BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_SKIP_FRAME;
+
+	err = arch_prepare_bpf_trampoline(im, im->image, im->image + PAGE_SIZE,
+					  &tr->func.model, flags, tprogs,
+					  tr->func.addr);
+	if (err < 0)
+		goto out;
+
+	WARN_ON(tr->cur_image && tr->selector == 0);
+	WARN_ON(!tr->cur_image && tr->selector);
+	if (tr->cur_image)
+		/* progs already running at this address */
+		err = modify_fentry(tr, tr->cur_image->image, im->image);
+	else
+		/* first time registering */
+		err = register_fentry(tr, im->image);
+	if (err)
+		goto out;
+	if (tr->cur_image)
+		bpf_tramp_image_put(tr->cur_image);
+	tr->cur_image = im;
+	tr->selector++;
+out:
+	kfree(tprogs);
+	return err;
+}
+
+static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog)
+{
+	switch (prog->expected_attach_type) {
+	case BPF_TRACE_FENTRY:
+		return BPF_TRAMP_FENTRY;
+	case BPF_MODIFY_RETURN:
+		return BPF_TRAMP_MODIFY_RETURN;
+	case BPF_TRACE_FEXIT:
+		return BPF_TRAMP_FEXIT;
+	case BPF_LSM_MAC:
+		if (!prog->aux->attach_func_proto->type)
+			/* The function returns void, we cannot modify its
+			 * return value.
+			 */
+			return BPF_TRAMP_FEXIT;
+		else
+			return BPF_TRAMP_MODIFY_RETURN;
+	default:
+		return BPF_TRAMP_REPLACE;
+	}
+}
+
+int bpf_trampoline_link_prog(struct bpf_prog *prog, struct bpf_trampoline *tr)
+{
+	enum bpf_tramp_prog_type kind;
+	int err = 0;
+	int cnt = 0, i;
+
+	kind = bpf_attach_type_to_tramp(prog);
+	mutex_lock(&tr->mutex);
+	if (tr->extension_prog) {
+		/* cannot attach fentry/fexit if extension prog is attached.
+		 * cannot overwrite extension prog either.
+		 */
+		err = -EBUSY;
+		goto out;
+	}
+
+	for (i = 0; i < BPF_TRAMP_MAX; i++)
+		cnt += tr->progs_cnt[i];
+
+	if (kind == BPF_TRAMP_REPLACE) {
+		/* Cannot attach extension if fentry/fexit are in use. */
+		if (cnt) {
+			err = -EBUSY;
+			goto out;
+		}
+		tr->extension_prog = prog;
+		err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL,
+					 prog->bpf_func);
+		goto out;
+	}
+	if (cnt >= BPF_MAX_TRAMP_PROGS) {
+		err = -E2BIG;
+		goto out;
+	}
+	if (!hlist_unhashed(&prog->aux->tramp_hlist)) {
+		/* prog already linked */
+		err = -EBUSY;
+		goto out;
+	}
+	hlist_add_head(&prog->aux->tramp_hlist, &tr->progs_hlist[kind]);
+	tr->progs_cnt[kind]++;
+	err = bpf_trampoline_update(tr);
+	if (err) {
+		hlist_del(&prog->aux->tramp_hlist);
+		tr->progs_cnt[kind]--;
+	}
+out:
+	mutex_unlock(&tr->mutex);
+	return err;
+}
+
+/* bpf_trampoline_unlink_prog() should never fail. */
+int bpf_trampoline_unlink_prog(struct bpf_prog *prog, struct bpf_trampoline *tr)
+{
+	enum bpf_tramp_prog_type kind;
+	int err;
+
+	kind = bpf_attach_type_to_tramp(prog);
+	mutex_lock(&tr->mutex);
+	if (kind == BPF_TRAMP_REPLACE) {
+		WARN_ON_ONCE(!tr->extension_prog);
+		err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP,
+					 tr->extension_prog->bpf_func, NULL);
+		tr->extension_prog = NULL;
+		goto out;
+	}
+	hlist_del(&prog->aux->tramp_hlist);
+	tr->progs_cnt[kind]--;
+	err = bpf_trampoline_update(tr);
+out:
+	mutex_unlock(&tr->mutex);
+	return err;
+}
+
+struct bpf_trampoline *bpf_trampoline_get(u64 key,
+					  struct bpf_attach_target_info *tgt_info)
+{
+	struct bpf_trampoline *tr;
+
+	tr = bpf_trampoline_lookup(key);
+	if (!tr)
+		return NULL;
+
+	mutex_lock(&tr->mutex);
+	if (tr->func.addr)
+		goto out;
+
+	memcpy(&tr->func.model, &tgt_info->fmodel, sizeof(tgt_info->fmodel));
+	tr->func.addr = (void *)tgt_info->tgt_addr;
+out:
+	mutex_unlock(&tr->mutex);
+	return tr;
+}
+
+void bpf_trampoline_put(struct bpf_trampoline *tr)
+{
+	int i;
+
+	if (!tr)
+		return;
+	mutex_lock(&trampoline_mutex);
+	if (!refcount_dec_and_test(&tr->refcnt))
+		goto out;
+	WARN_ON_ONCE(mutex_is_locked(&tr->mutex));
+
+	for (i = 0; i < BPF_TRAMP_MAX; i++)
+		if (WARN_ON_ONCE(!hlist_empty(&tr->progs_hlist[i])))
+			goto out;
+
+	/* This code will be executed even when the last bpf_tramp_image
+	 * is alive. All progs are detached from the trampoline and the
+	 * trampoline image is patched with jmp into epilogue to skip
+	 * fexit progs. The fentry-only trampoline will be freed via
+	 * multiple rcu callbacks.
+	 */
+	hlist_del(&tr->hlist);
+	kfree(tr);
+out:
+	mutex_unlock(&trampoline_mutex);
+}
+
+/* The logic is similar to BPF_PROG_RUN, but with an explicit
+ * rcu_read_lock() and migrate_disable() which are required
+ * for the trampoline. The macro is split into
+ * call _bpf_prog_enter
+ * call prog->bpf_func
+ * call __bpf_prog_exit
+ */
+u64 notrace __bpf_prog_enter(void)
+	__acquires(RCU)
+{
+	u64 start = 0;
+
+	rcu_read_lock();
+	migrate_disable();
+	if (static_branch_unlikely(&bpf_stats_enabled_key))
+		start = sched_clock();
+	return start;
+}
+
+void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start)
+	__releases(RCU)
+{
+	struct bpf_prog_stats *stats;
+
+	if (static_branch_unlikely(&bpf_stats_enabled_key) &&
+	    /* static_key could be enabled in __bpf_prog_enter
+	     * and disabled in __bpf_prog_exit.
+	     * And vice versa.
+	     * Hence check that 'start' is not zero.
+	     */
+	    start) {
+		stats = this_cpu_ptr(prog->aux->stats);
+		u64_stats_update_begin(&stats->syncp);
+		stats->cnt++;
+		stats->nsecs += sched_clock() - start;
+		u64_stats_update_end(&stats->syncp);
+	}
+	migrate_enable();
+	rcu_read_unlock();
+}
+
+void notrace __bpf_prog_enter_sleepable(void)
+{
+	rcu_read_lock_trace();
+	might_fault();
+}
+
+void notrace __bpf_prog_exit_sleepable(void)
+{
+	rcu_read_unlock_trace();
+}
+
+void notrace __bpf_tramp_enter(struct bpf_tramp_image *tr)
+{
+	percpu_ref_get(&tr->pcref);
+}
+
+void notrace __bpf_tramp_exit(struct bpf_tramp_image *tr)
+{
+	percpu_ref_put(&tr->pcref);
+}
+
+int __weak
+arch_prepare_bpf_trampoline(struct bpf_tramp_image *tr, void *image, void *image_end,
+			    const struct btf_func_model *m, u32 flags,
+			    struct bpf_tramp_progs *tprogs,
+			    void *orig_call)
+{
+	return -ENOTSUPP;
+}
+
+static int __init init_trampolines(void)
+{
+	int i;
+
+	for (i = 0; i < TRAMPOLINE_TABLE_SIZE; i++)
+		INIT_HLIST_HEAD(&trampoline_table[i]);
+	return 0;
+}
+late_initcall(init_trampolines);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
new file mode 100644
index 000000000..fce2345f6
--- /dev/null
+++ b/kernel/bpf/verifier.c
@@ -0,0 +1,12742 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016 Facebook
+ * Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
+ */
+#include <uapi/linux/btf.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/bpf_verifier.h>
+#include <linux/filter.h>
+#include <net/netlink.h>
+#include <linux/file.h>
+#include <linux/vmalloc.h>
+#include <linux/stringify.h>
+#include <linux/bsearch.h>
+#include <linux/sort.h>
+#include <linux/perf_event.h>
+#include <linux/ctype.h>
+#include <linux/error-injection.h>
+#include <linux/bpf_lsm.h>
+#include <linux/btf_ids.h>
+
+#include "disasm.h"
+
+static const struct bpf_verifier_ops * const bpf_verifier_ops[] = {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	[_id] = & _name ## _verifier_ops,
+#define BPF_MAP_TYPE(_id, _ops)
+#define BPF_LINK_TYPE(_id, _name)
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+#undef BPF_MAP_TYPE
+#undef BPF_LINK_TYPE
+};
+
+/* bpf_check() is a static code analyzer that walks eBPF program
+ * instruction by instruction and updates register/stack state.
+ * All paths of conditional branches are analyzed until 'bpf_exit' insn.
+ *
+ * The first pass is depth-first-search to check that the program is a DAG.
+ * It rejects the following programs:
+ * - larger than BPF_MAXINSNS insns
+ * - if loop is present (detected via back-edge)
+ * - unreachable insns exist (shouldn't be a forest. program = one function)
+ * - out of bounds or malformed jumps
+ * The second pass is all possible path descent from the 1st insn.
+ * Since it's analyzing all pathes through the program, the length of the
+ * analysis is limited to 64k insn, which may be hit even if total number of
+ * insn is less then 4K, but there are too many branches that change stack/regs.
+ * Number of 'branches to be analyzed' is limited to 1k
+ *
+ * On entry to each instruction, each register has a type, and the instruction
+ * changes the types of the registers depending on instruction semantics.
+ * If instruction is BPF_MOV64_REG(BPF_REG_1, BPF_REG_5), then type of R5 is
+ * copied to R1.
+ *
+ * All registers are 64-bit.
+ * R0 - return register
+ * R1-R5 argument passing registers
+ * R6-R9 callee saved registers
+ * R10 - frame pointer read-only
+ *
+ * At the start of BPF program the register R1 contains a pointer to bpf_context
+ * and has type PTR_TO_CTX.
+ *
+ * Verifier tracks arithmetic operations on pointers in case:
+ *    BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+ *    BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -20),
+ * 1st insn copies R10 (which has FRAME_PTR) type into R1
+ * and 2nd arithmetic instruction is pattern matched to recognize
+ * that it wants to construct a pointer to some element within stack.
+ * So after 2nd insn, the register R1 has type PTR_TO_STACK
+ * (and -20 constant is saved for further stack bounds checking).
+ * Meaning that this reg is a pointer to stack plus known immediate constant.
+ *
+ * Most of the time the registers have SCALAR_VALUE type, which
+ * means the register has some value, but it's not a valid pointer.
+ * (like pointer plus pointer becomes SCALAR_VALUE type)
+ *
+ * When verifier sees load or store instructions the type of base register
+ * can be: PTR_TO_MAP_VALUE, PTR_TO_CTX, PTR_TO_STACK, PTR_TO_SOCKET. These are
+ * four pointer types recognized by check_mem_access() function.
+ *
+ * PTR_TO_MAP_VALUE means that this register is pointing to 'map element value'
+ * and the range of [ptr, ptr + map's value_size) is accessible.
+ *
+ * registers used to pass values to function calls are checked against
+ * function argument constraints.
+ *
+ * ARG_PTR_TO_MAP_KEY is one of such argument constraints.
+ * It means that the register type passed to this function must be
+ * PTR_TO_STACK and it will be used inside the function as
+ * 'pointer to map element key'
+ *
+ * For example the argument constraints for bpf_map_lookup_elem():
+ *   .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
+ *   .arg1_type = ARG_CONST_MAP_PTR,
+ *   .arg2_type = ARG_PTR_TO_MAP_KEY,
+ *
+ * ret_type says that this function returns 'pointer to map elem value or null'
+ * function expects 1st argument to be a const pointer to 'struct bpf_map' and
+ * 2nd argument should be a pointer to stack, which will be used inside
+ * the helper function as a pointer to map element key.
+ *
+ * On the kernel side the helper function looks like:
+ * u64 bpf_map_lookup_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+ * {
+ *    struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
+ *    void *key = (void *) (unsigned long) r2;
+ *    void *value;
+ *
+ *    here kernel can access 'key' and 'map' pointers safely, knowing that
+ *    [key, key + map->key_size) bytes are valid and were initialized on
+ *    the stack of eBPF program.
+ * }
+ *
+ * Corresponding eBPF program may look like:
+ *    BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),  // after this insn R2 type is FRAME_PTR
+ *    BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), // after this insn R2 type is PTR_TO_STACK
+ *    BPF_LD_MAP_FD(BPF_REG_1, map_fd),      // after this insn R1 type is CONST_PTR_TO_MAP
+ *    BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+ * here verifier looks at prototype of map_lookup_elem() and sees:
+ * .arg1_type == ARG_CONST_MAP_PTR and R1->type == CONST_PTR_TO_MAP, which is ok,
+ * Now verifier knows that this map has key of R1->map_ptr->key_size bytes
+ *
+ * Then .arg2_type == ARG_PTR_TO_MAP_KEY and R2->type == PTR_TO_STACK, ok so far,
+ * Now verifier checks that [R2, R2 + map's key_size) are within stack limits
+ * and were initialized prior to this call.
+ * If it's ok, then verifier allows this BPF_CALL insn and looks at
+ * .ret_type which is RET_PTR_TO_MAP_VALUE_OR_NULL, so it sets
+ * R0->type = PTR_TO_MAP_VALUE_OR_NULL which means bpf_map_lookup_elem() function
+ * returns ether pointer to map value or NULL.
+ *
+ * When type PTR_TO_MAP_VALUE_OR_NULL passes through 'if (reg != 0) goto +off'
+ * insn, the register holding that pointer in the true branch changes state to
+ * PTR_TO_MAP_VALUE and the same register changes state to CONST_IMM in the false
+ * branch. See check_cond_jmp_op().
+ *
+ * After the call R0 is set to return type of the function and registers R1-R5
+ * are set to NOT_INIT to indicate that they are no longer readable.
+ *
+ * The following reference types represent a potential reference to a kernel
+ * resource which, after first being allocated, must be checked and freed by
+ * the BPF program:
+ * - PTR_TO_SOCKET_OR_NULL, PTR_TO_SOCKET
+ *
+ * When the verifier sees a helper call return a reference type, it allocates a
+ * pointer id for the reference and stores it in the current function state.
+ * Similar to the way that PTR_TO_MAP_VALUE_OR_NULL is converted into
+ * PTR_TO_MAP_VALUE, PTR_TO_SOCKET_OR_NULL becomes PTR_TO_SOCKET when the type
+ * passes through a NULL-check conditional. For the branch wherein the state is
+ * changed to CONST_IMM, the verifier releases the reference.
+ *
+ * For each helper function that allocates a reference, such as
+ * bpf_sk_lookup_tcp(), there is a corresponding release function, such as
+ * bpf_sk_release(). When a reference type passes into the release function,
+ * the verifier also releases the reference. If any unchecked or unreleased
+ * reference remains at the end of the program, the verifier rejects it.
+ */
+
+/* verifier_state + insn_idx are pushed to stack when branch is encountered */
+struct bpf_verifier_stack_elem {
+	/* verifer state is 'st'
+	 * before processing instruction 'insn_idx'
+	 * and after processing instruction 'prev_insn_idx'
+	 */
+	struct bpf_verifier_state st;
+	int insn_idx;
+	int prev_insn_idx;
+	struct bpf_verifier_stack_elem *next;
+	/* length of verifier log at the time this state was pushed on stack */
+	u32 log_pos;
+};
+
+#define BPF_COMPLEXITY_LIMIT_JMP_SEQ	8192
+#define BPF_COMPLEXITY_LIMIT_STATES	64
+
+#define BPF_MAP_KEY_POISON	(1ULL << 63)
+#define BPF_MAP_KEY_SEEN	(1ULL << 62)
+
+#define BPF_MAP_PTR_UNPRIV	1UL
+#define BPF_MAP_PTR_POISON	((void *)((0xeB9FUL << 1) +	\
+					  POISON_POINTER_DELTA))
+#define BPF_MAP_PTR(X)		((struct bpf_map *)((X) & ~BPF_MAP_PTR_UNPRIV))
+
+static bool bpf_map_ptr_poisoned(const struct bpf_insn_aux_data *aux)
+{
+	return BPF_MAP_PTR(aux->map_ptr_state) == BPF_MAP_PTR_POISON;
+}
+
+static bool bpf_map_ptr_unpriv(const struct bpf_insn_aux_data *aux)
+{
+	return aux->map_ptr_state & BPF_MAP_PTR_UNPRIV;
+}
+
+static void bpf_map_ptr_store(struct bpf_insn_aux_data *aux,
+			      const struct bpf_map *map, bool unpriv)
+{
+	BUILD_BUG_ON((unsigned long)BPF_MAP_PTR_POISON & BPF_MAP_PTR_UNPRIV);
+	unpriv |= bpf_map_ptr_unpriv(aux);
+	aux->map_ptr_state = (unsigned long)map |
+			     (unpriv ? BPF_MAP_PTR_UNPRIV : 0UL);
+}
+
+static bool bpf_map_key_poisoned(const struct bpf_insn_aux_data *aux)
+{
+	return aux->map_key_state & BPF_MAP_KEY_POISON;
+}
+
+static bool bpf_map_key_unseen(const struct bpf_insn_aux_data *aux)
+{
+	return !(aux->map_key_state & BPF_MAP_KEY_SEEN);
+}
+
+static u64 bpf_map_key_immediate(const struct bpf_insn_aux_data *aux)
+{
+	return aux->map_key_state & ~(BPF_MAP_KEY_SEEN | BPF_MAP_KEY_POISON);
+}
+
+static void bpf_map_key_store(struct bpf_insn_aux_data *aux, u64 state)
+{
+	bool poisoned = bpf_map_key_poisoned(aux);
+
+	aux->map_key_state = state | BPF_MAP_KEY_SEEN |
+			     (poisoned ? BPF_MAP_KEY_POISON : 0ULL);
+}
+
+struct bpf_call_arg_meta {
+	struct bpf_map *map_ptr;
+	bool raw_mode;
+	bool pkt_access;
+	int regno;
+	int access_size;
+	int mem_size;
+	u64 msize_max_value;
+	int ref_obj_id;
+	int func_id;
+	u32 btf_id;
+	u32 ret_btf_id;
+};
+
+struct btf *btf_vmlinux;
+
+static DEFINE_MUTEX(bpf_verifier_lock);
+
+static const struct bpf_line_info *
+find_linfo(const struct bpf_verifier_env *env, u32 insn_off)
+{
+	const struct bpf_line_info *linfo;
+	const struct bpf_prog *prog;
+	u32 i, nr_linfo;
+
+	prog = env->prog;
+	nr_linfo = prog->aux->nr_linfo;
+
+	if (!nr_linfo || insn_off >= prog->len)
+		return NULL;
+
+	linfo = prog->aux->linfo;
+	for (i = 1; i < nr_linfo; i++)
+		if (insn_off < linfo[i].insn_off)
+			break;
+
+	return &linfo[i - 1];
+}
+
+void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
+		       va_list args)
+{
+	unsigned int n;
+
+	n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args);
+
+	WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1,
+		  "verifier log line truncated - local buffer too short\n");
+
+	n = min(log->len_total - log->len_used - 1, n);
+	log->kbuf[n] = '\0';
+
+	if (log->level == BPF_LOG_KERNEL) {
+		pr_err("BPF:%s\n", log->kbuf);
+		return;
+	}
+	if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1))
+		log->len_used += n;
+	else
+		log->ubuf = NULL;
+}
+
+static void bpf_vlog_reset(struct bpf_verifier_log *log, u32 new_pos)
+{
+	char zero = 0;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+
+	log->len_used = new_pos;
+	if (put_user(zero, log->ubuf + new_pos))
+		log->ubuf = NULL;
+}
+
+/* log_level controls verbosity level of eBPF verifier.
+ * bpf_verifier_log_write() is used to dump the verification trace to the log,
+ * so the user can figure out what's wrong with the program
+ */
+__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
+					   const char *fmt, ...)
+{
+	va_list args;
+
+	if (!bpf_verifier_log_needed(&env->log))
+		return;
+
+	va_start(args, fmt);
+	bpf_verifier_vlog(&env->log, fmt, args);
+	va_end(args);
+}
+EXPORT_SYMBOL_GPL(bpf_verifier_log_write);
+
+__printf(2, 3) static void verbose(void *private_data, const char *fmt, ...)
+{
+	struct bpf_verifier_env *env = private_data;
+	va_list args;
+
+	if (!bpf_verifier_log_needed(&env->log))
+		return;
+
+	va_start(args, fmt);
+	bpf_verifier_vlog(&env->log, fmt, args);
+	va_end(args);
+}
+
+__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
+			    const char *fmt, ...)
+{
+	va_list args;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+
+	va_start(args, fmt);
+	bpf_verifier_vlog(log, fmt, args);
+	va_end(args);
+}
+
+static const char *ltrim(const char *s)
+{
+	while (isspace(*s))
+		s++;
+
+	return s;
+}
+
+__printf(3, 4) static void verbose_linfo(struct bpf_verifier_env *env,
+					 u32 insn_off,
+					 const char *prefix_fmt, ...)
+{
+	const struct bpf_line_info *linfo;
+
+	if (!bpf_verifier_log_needed(&env->log))
+		return;
+
+	linfo = find_linfo(env, insn_off);
+	if (!linfo || linfo == env->prev_linfo)
+		return;
+
+	if (prefix_fmt) {
+		va_list args;
+
+		va_start(args, prefix_fmt);
+		bpf_verifier_vlog(&env->log, prefix_fmt, args);
+		va_end(args);
+	}
+
+	verbose(env, "%s\n",
+		ltrim(btf_name_by_offset(env->prog->aux->btf,
+					 linfo->line_off)));
+
+	env->prev_linfo = linfo;
+}
+
+static bool type_is_pkt_pointer(enum bpf_reg_type type)
+{
+	return type == PTR_TO_PACKET ||
+	       type == PTR_TO_PACKET_META;
+}
+
+static bool type_is_sk_pointer(enum bpf_reg_type type)
+{
+	return type == PTR_TO_SOCKET ||
+		type == PTR_TO_SOCK_COMMON ||
+		type == PTR_TO_TCP_SOCK ||
+		type == PTR_TO_XDP_SOCK;
+}
+
+static bool reg_type_not_null(enum bpf_reg_type type)
+{
+	return type == PTR_TO_SOCKET ||
+		type == PTR_TO_TCP_SOCK ||
+		type == PTR_TO_MAP_VALUE ||
+		type == PTR_TO_SOCK_COMMON;
+}
+
+static bool reg_type_may_be_null(enum bpf_reg_type type)
+{
+	return type == PTR_TO_MAP_VALUE_OR_NULL ||
+	       type == PTR_TO_SOCKET_OR_NULL ||
+	       type == PTR_TO_SOCK_COMMON_OR_NULL ||
+	       type == PTR_TO_TCP_SOCK_OR_NULL ||
+	       type == PTR_TO_BTF_ID_OR_NULL ||
+	       type == PTR_TO_MEM_OR_NULL ||
+	       type == PTR_TO_RDONLY_BUF_OR_NULL ||
+	       type == PTR_TO_RDWR_BUF_OR_NULL;
+}
+
+static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
+{
+	return reg->type == PTR_TO_MAP_VALUE &&
+		map_value_has_spin_lock(reg->map_ptr);
+}
+
+static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type)
+{
+	return type == PTR_TO_SOCKET ||
+		type == PTR_TO_SOCKET_OR_NULL ||
+		type == PTR_TO_TCP_SOCK ||
+		type == PTR_TO_TCP_SOCK_OR_NULL ||
+		type == PTR_TO_MEM ||
+		type == PTR_TO_MEM_OR_NULL;
+}
+
+static bool arg_type_may_be_refcounted(enum bpf_arg_type type)
+{
+	return type == ARG_PTR_TO_SOCK_COMMON;
+}
+
+static bool arg_type_may_be_null(enum bpf_arg_type type)
+{
+	return type == ARG_PTR_TO_MAP_VALUE_OR_NULL ||
+	       type == ARG_PTR_TO_MEM_OR_NULL ||
+	       type == ARG_PTR_TO_CTX_OR_NULL ||
+	       type == ARG_PTR_TO_SOCKET_OR_NULL ||
+	       type == ARG_PTR_TO_ALLOC_MEM_OR_NULL;
+}
+
+/* Determine whether the function releases some resources allocated by another
+ * function call. The first reference type argument will be assumed to be
+ * released by release_reference().
+ */
+static bool is_release_function(enum bpf_func_id func_id)
+{
+	return func_id == BPF_FUNC_sk_release ||
+	       func_id == BPF_FUNC_ringbuf_submit ||
+	       func_id == BPF_FUNC_ringbuf_discard;
+}
+
+static bool may_be_acquire_function(enum bpf_func_id func_id)
+{
+	return func_id == BPF_FUNC_sk_lookup_tcp ||
+		func_id == BPF_FUNC_sk_lookup_udp ||
+		func_id == BPF_FUNC_skc_lookup_tcp ||
+		func_id == BPF_FUNC_map_lookup_elem ||
+	        func_id == BPF_FUNC_ringbuf_reserve;
+}
+
+static bool is_acquire_function(enum bpf_func_id func_id,
+				const struct bpf_map *map)
+{
+	enum bpf_map_type map_type = map ? map->map_type : BPF_MAP_TYPE_UNSPEC;
+
+	if (func_id == BPF_FUNC_sk_lookup_tcp ||
+	    func_id == BPF_FUNC_sk_lookup_udp ||
+	    func_id == BPF_FUNC_skc_lookup_tcp ||
+	    func_id == BPF_FUNC_ringbuf_reserve)
+		return true;
+
+	if (func_id == BPF_FUNC_map_lookup_elem &&
+	    (map_type == BPF_MAP_TYPE_SOCKMAP ||
+	     map_type == BPF_MAP_TYPE_SOCKHASH))
+		return true;
+
+	return false;
+}
+
+static bool is_ptr_cast_function(enum bpf_func_id func_id)
+{
+	return func_id == BPF_FUNC_tcp_sock ||
+		func_id == BPF_FUNC_sk_fullsock ||
+		func_id == BPF_FUNC_skc_to_tcp_sock ||
+		func_id == BPF_FUNC_skc_to_tcp6_sock ||
+		func_id == BPF_FUNC_skc_to_udp6_sock ||
+		func_id == BPF_FUNC_skc_to_tcp_timewait_sock ||
+		func_id == BPF_FUNC_skc_to_tcp_request_sock;
+}
+
+/* string representation of 'enum bpf_reg_type' */
+static const char * const reg_type_str[] = {
+	[NOT_INIT]		= "?",
+	[SCALAR_VALUE]		= "inv",
+	[PTR_TO_CTX]		= "ctx",
+	[CONST_PTR_TO_MAP]	= "map_ptr",
+	[PTR_TO_MAP_VALUE]	= "map_value",
+	[PTR_TO_MAP_VALUE_OR_NULL] = "map_value_or_null",
+	[PTR_TO_STACK]		= "fp",
+	[PTR_TO_PACKET]		= "pkt",
+	[PTR_TO_PACKET_META]	= "pkt_meta",
+	[PTR_TO_PACKET_END]	= "pkt_end",
+	[PTR_TO_FLOW_KEYS]	= "flow_keys",
+	[PTR_TO_SOCKET]		= "sock",
+	[PTR_TO_SOCKET_OR_NULL] = "sock_or_null",
+	[PTR_TO_SOCK_COMMON]	= "sock_common",
+	[PTR_TO_SOCK_COMMON_OR_NULL] = "sock_common_or_null",
+	[PTR_TO_TCP_SOCK]	= "tcp_sock",
+	[PTR_TO_TCP_SOCK_OR_NULL] = "tcp_sock_or_null",
+	[PTR_TO_TP_BUFFER]	= "tp_buffer",
+	[PTR_TO_XDP_SOCK]	= "xdp_sock",
+	[PTR_TO_BTF_ID]		= "ptr_",
+	[PTR_TO_BTF_ID_OR_NULL]	= "ptr_or_null_",
+	[PTR_TO_PERCPU_BTF_ID]	= "percpu_ptr_",
+	[PTR_TO_MEM]		= "mem",
+	[PTR_TO_MEM_OR_NULL]	= "mem_or_null",
+	[PTR_TO_RDONLY_BUF]	= "rdonly_buf",
+	[PTR_TO_RDONLY_BUF_OR_NULL] = "rdonly_buf_or_null",
+	[PTR_TO_RDWR_BUF]	= "rdwr_buf",
+	[PTR_TO_RDWR_BUF_OR_NULL] = "rdwr_buf_or_null",
+};
+
+static char slot_type_char[] = {
+	[STACK_INVALID]	= '?',
+	[STACK_SPILL]	= 'r',
+	[STACK_MISC]	= 'm',
+	[STACK_ZERO]	= '0',
+};
+
+static void print_liveness(struct bpf_verifier_env *env,
+			   enum bpf_reg_liveness live)
+{
+	if (live & (REG_LIVE_READ | REG_LIVE_WRITTEN | REG_LIVE_DONE))
+	    verbose(env, "_");
+	if (live & REG_LIVE_READ)
+		verbose(env, "r");
+	if (live & REG_LIVE_WRITTEN)
+		verbose(env, "w");
+	if (live & REG_LIVE_DONE)
+		verbose(env, "D");
+}
+
+static struct bpf_func_state *func(struct bpf_verifier_env *env,
+				   const struct bpf_reg_state *reg)
+{
+	struct bpf_verifier_state *cur = env->cur_state;
+
+	return cur->frame[reg->frameno];
+}
+
+const char *kernel_type_name(u32 id)
+{
+	return btf_name_by_offset(btf_vmlinux,
+				  btf_type_by_id(btf_vmlinux, id)->name_off);
+}
+
+/* The reg state of a pointer or a bounded scalar was saved when
+ * it was spilled to the stack.
+ */
+static bool is_spilled_reg(const struct bpf_stack_state *stack)
+{
+	return stack->slot_type[BPF_REG_SIZE - 1] == STACK_SPILL;
+}
+
+static void scrub_spilled_slot(u8 *stype)
+{
+	if (*stype != STACK_INVALID)
+		*stype = STACK_MISC;
+}
+
+static void print_verifier_state(struct bpf_verifier_env *env,
+				 const struct bpf_func_state *state)
+{
+	const struct bpf_reg_state *reg;
+	enum bpf_reg_type t;
+	int i;
+
+	if (state->frameno)
+		verbose(env, " frame%d:", state->frameno);
+	for (i = 0; i < MAX_BPF_REG; i++) {
+		reg = &state->regs[i];
+		t = reg->type;
+		if (t == NOT_INIT)
+			continue;
+		verbose(env, " R%d", i);
+		print_liveness(env, reg->live);
+		verbose(env, "=%s", reg_type_str[t]);
+		if (t == SCALAR_VALUE && reg->precise)
+			verbose(env, "P");
+		if ((t == SCALAR_VALUE || t == PTR_TO_STACK) &&
+		    tnum_is_const(reg->var_off)) {
+			/* reg->off should be 0 for SCALAR_VALUE */
+			verbose(env, "%lld", reg->var_off.value + reg->off);
+		} else {
+			if (t == PTR_TO_BTF_ID ||
+			    t == PTR_TO_BTF_ID_OR_NULL ||
+			    t == PTR_TO_PERCPU_BTF_ID)
+				verbose(env, "%s", kernel_type_name(reg->btf_id));
+			verbose(env, "(id=%d", reg->id);
+			if (reg_type_may_be_refcounted_or_null(t))
+				verbose(env, ",ref_obj_id=%d", reg->ref_obj_id);
+			if (t != SCALAR_VALUE)
+				verbose(env, ",off=%d", reg->off);
+			if (type_is_pkt_pointer(t))
+				verbose(env, ",r=%d", reg->range);
+			else if (t == CONST_PTR_TO_MAP ||
+				 t == PTR_TO_MAP_VALUE ||
+				 t == PTR_TO_MAP_VALUE_OR_NULL)
+				verbose(env, ",ks=%d,vs=%d",
+					reg->map_ptr->key_size,
+					reg->map_ptr->value_size);
+			if (tnum_is_const(reg->var_off)) {
+				/* Typically an immediate SCALAR_VALUE, but
+				 * could be a pointer whose offset is too big
+				 * for reg->off
+				 */
+				verbose(env, ",imm=%llx", reg->var_off.value);
+			} else {
+				if (reg->smin_value != reg->umin_value &&
+				    reg->smin_value != S64_MIN)
+					verbose(env, ",smin_value=%lld",
+						(long long)reg->smin_value);
+				if (reg->smax_value != reg->umax_value &&
+				    reg->smax_value != S64_MAX)
+					verbose(env, ",smax_value=%lld",
+						(long long)reg->smax_value);
+				if (reg->umin_value != 0)
+					verbose(env, ",umin_value=%llu",
+						(unsigned long long)reg->umin_value);
+				if (reg->umax_value != U64_MAX)
+					verbose(env, ",umax_value=%llu",
+						(unsigned long long)reg->umax_value);
+				if (!tnum_is_unknown(reg->var_off)) {
+					char tn_buf[48];
+
+					tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+					verbose(env, ",var_off=%s", tn_buf);
+				}
+				if (reg->s32_min_value != reg->smin_value &&
+				    reg->s32_min_value != S32_MIN)
+					verbose(env, ",s32_min_value=%d",
+						(int)(reg->s32_min_value));
+				if (reg->s32_max_value != reg->smax_value &&
+				    reg->s32_max_value != S32_MAX)
+					verbose(env, ",s32_max_value=%d",
+						(int)(reg->s32_max_value));
+				if (reg->u32_min_value != reg->umin_value &&
+				    reg->u32_min_value != U32_MIN)
+					verbose(env, ",u32_min_value=%d",
+						(int)(reg->u32_min_value));
+				if (reg->u32_max_value != reg->umax_value &&
+				    reg->u32_max_value != U32_MAX)
+					verbose(env, ",u32_max_value=%d",
+						(int)(reg->u32_max_value));
+			}
+			verbose(env, ")");
+		}
+	}
+	for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
+		char types_buf[BPF_REG_SIZE + 1];
+		bool valid = false;
+		int j;
+
+		for (j = 0; j < BPF_REG_SIZE; j++) {
+			if (state->stack[i].slot_type[j] != STACK_INVALID)
+				valid = true;
+			types_buf[j] = slot_type_char[
+					state->stack[i].slot_type[j]];
+		}
+		types_buf[BPF_REG_SIZE] = 0;
+		if (!valid)
+			continue;
+		verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
+		print_liveness(env, state->stack[i].spilled_ptr.live);
+		if (is_spilled_reg(&state->stack[i])) {
+			reg = &state->stack[i].spilled_ptr;
+			t = reg->type;
+			verbose(env, "=%s", reg_type_str[t]);
+			if (t == SCALAR_VALUE && reg->precise)
+				verbose(env, "P");
+			if (t == SCALAR_VALUE && tnum_is_const(reg->var_off))
+				verbose(env, "%lld", reg->var_off.value + reg->off);
+		} else {
+			verbose(env, "=%s", types_buf);
+		}
+	}
+	if (state->acquired_refs && state->refs[0].id) {
+		verbose(env, " refs=%d", state->refs[0].id);
+		for (i = 1; i < state->acquired_refs; i++)
+			if (state->refs[i].id)
+				verbose(env, ",%d", state->refs[i].id);
+	}
+	verbose(env, "\n");
+}
+
+#define COPY_STATE_FN(NAME, COUNT, FIELD, SIZE)				\
+static int copy_##NAME##_state(struct bpf_func_state *dst,		\
+			       const struct bpf_func_state *src)	\
+{									\
+	if (!src->FIELD)						\
+		return 0;						\
+	if (WARN_ON_ONCE(dst->COUNT < src->COUNT)) {			\
+		/* internal bug, make state invalid to reject the program */ \
+		memset(dst, 0, sizeof(*dst));				\
+		return -EFAULT;						\
+	}								\
+	memcpy(dst->FIELD, src->FIELD,					\
+	       sizeof(*src->FIELD) * (src->COUNT / SIZE));		\
+	return 0;							\
+}
+/* copy_reference_state() */
+COPY_STATE_FN(reference, acquired_refs, refs, 1)
+/* copy_stack_state() */
+COPY_STATE_FN(stack, allocated_stack, stack, BPF_REG_SIZE)
+#undef COPY_STATE_FN
+
+#define REALLOC_STATE_FN(NAME, COUNT, FIELD, SIZE)			\
+static int realloc_##NAME##_state(struct bpf_func_state *state, int size, \
+				  bool copy_old)			\
+{									\
+	u32 old_size = state->COUNT;					\
+	struct bpf_##NAME##_state *new_##FIELD;				\
+	int slot = size / SIZE;						\
+									\
+	if (size <= old_size || !size) {				\
+		if (copy_old)						\
+			return 0;					\
+		state->COUNT = slot * SIZE;				\
+		if (!size && old_size) {				\
+			kfree(state->FIELD);				\
+			state->FIELD = NULL;				\
+		}							\
+		return 0;						\
+	}								\
+	new_##FIELD = kmalloc_array(slot, sizeof(struct bpf_##NAME##_state), \
+				    GFP_KERNEL);			\
+	if (!new_##FIELD)						\
+		return -ENOMEM;						\
+	if (copy_old) {							\
+		if (state->FIELD)					\
+			memcpy(new_##FIELD, state->FIELD,		\
+			       sizeof(*new_##FIELD) * (old_size / SIZE)); \
+		memset(new_##FIELD + old_size / SIZE, 0,		\
+		       sizeof(*new_##FIELD) * (size - old_size) / SIZE); \
+	}								\
+	state->COUNT = slot * SIZE;					\
+	kfree(state->FIELD);						\
+	state->FIELD = new_##FIELD;					\
+	return 0;							\
+}
+/* realloc_reference_state() */
+REALLOC_STATE_FN(reference, acquired_refs, refs, 1)
+/* realloc_stack_state() */
+REALLOC_STATE_FN(stack, allocated_stack, stack, BPF_REG_SIZE)
+#undef REALLOC_STATE_FN
+
+/* do_check() starts with zero-sized stack in struct bpf_verifier_state to
+ * make it consume minimal amount of memory. check_stack_write() access from
+ * the program calls into realloc_func_state() to grow the stack size.
+ * Note there is a non-zero 'parent' pointer inside bpf_verifier_state
+ * which realloc_stack_state() copies over. It points to previous
+ * bpf_verifier_state which is never reallocated.
+ */
+static int realloc_func_state(struct bpf_func_state *state, int stack_size,
+			      int refs_size, bool copy_old)
+{
+	int err = realloc_reference_state(state, refs_size, copy_old);
+	if (err)
+		return err;
+	return realloc_stack_state(state, stack_size, copy_old);
+}
+
+/* Acquire a pointer id from the env and update the state->refs to include
+ * this new pointer reference.
+ * On success, returns a valid pointer id to associate with the register
+ * On failure, returns a negative errno.
+ */
+static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx)
+{
+	struct bpf_func_state *state = cur_func(env);
+	int new_ofs = state->acquired_refs;
+	int id, err;
+
+	err = realloc_reference_state(state, state->acquired_refs + 1, true);
+	if (err)
+		return err;
+	id = ++env->id_gen;
+	state->refs[new_ofs].id = id;
+	state->refs[new_ofs].insn_idx = insn_idx;
+
+	return id;
+}
+
+/* release function corresponding to acquire_reference_state(). Idempotent. */
+static int release_reference_state(struct bpf_func_state *state, int ptr_id)
+{
+	int i, last_idx;
+
+	last_idx = state->acquired_refs - 1;
+	for (i = 0; i < state->acquired_refs; i++) {
+		if (state->refs[i].id == ptr_id) {
+			if (last_idx && i != last_idx)
+				memcpy(&state->refs[i], &state->refs[last_idx],
+				       sizeof(*state->refs));
+			memset(&state->refs[last_idx], 0, sizeof(*state->refs));
+			state->acquired_refs--;
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static int transfer_reference_state(struct bpf_func_state *dst,
+				    struct bpf_func_state *src)
+{
+	int err = realloc_reference_state(dst, src->acquired_refs, false);
+	if (err)
+		return err;
+	err = copy_reference_state(dst, src);
+	if (err)
+		return err;
+	return 0;
+}
+
+static void free_func_state(struct bpf_func_state *state)
+{
+	if (!state)
+		return;
+	kfree(state->refs);
+	kfree(state->stack);
+	kfree(state);
+}
+
+static void clear_jmp_history(struct bpf_verifier_state *state)
+{
+	kfree(state->jmp_history);
+	state->jmp_history = NULL;
+	state->jmp_history_cnt = 0;
+}
+
+static void free_verifier_state(struct bpf_verifier_state *state,
+				bool free_self)
+{
+	int i;
+
+	for (i = 0; i <= state->curframe; i++) {
+		free_func_state(state->frame[i]);
+		state->frame[i] = NULL;
+	}
+	clear_jmp_history(state);
+	if (free_self)
+		kfree(state);
+}
+
+/* copy verifier state from src to dst growing dst stack space
+ * when necessary to accommodate larger src stack
+ */
+static int copy_func_state(struct bpf_func_state *dst,
+			   const struct bpf_func_state *src)
+{
+	int err;
+
+	err = realloc_func_state(dst, src->allocated_stack, src->acquired_refs,
+				 false);
+	if (err)
+		return err;
+	memcpy(dst, src, offsetof(struct bpf_func_state, acquired_refs));
+	err = copy_reference_state(dst, src);
+	if (err)
+		return err;
+	return copy_stack_state(dst, src);
+}
+
+static int copy_verifier_state(struct bpf_verifier_state *dst_state,
+			       const struct bpf_verifier_state *src)
+{
+	struct bpf_func_state *dst;
+	u32 jmp_sz = sizeof(struct bpf_idx_pair) * src->jmp_history_cnt;
+	int i, err;
+
+	if (dst_state->jmp_history_cnt < src->jmp_history_cnt) {
+		kfree(dst_state->jmp_history);
+		dst_state->jmp_history = kmalloc(jmp_sz, GFP_USER);
+		if (!dst_state->jmp_history)
+			return -ENOMEM;
+	}
+	memcpy(dst_state->jmp_history, src->jmp_history, jmp_sz);
+	dst_state->jmp_history_cnt = src->jmp_history_cnt;
+
+	/* if dst has more stack frames then src frame, free them */
+	for (i = src->curframe + 1; i <= dst_state->curframe; i++) {
+		free_func_state(dst_state->frame[i]);
+		dst_state->frame[i] = NULL;
+	}
+	dst_state->speculative = src->speculative;
+	dst_state->curframe = src->curframe;
+	dst_state->active_spin_lock = src->active_spin_lock;
+	dst_state->branches = src->branches;
+	dst_state->parent = src->parent;
+	dst_state->first_insn_idx = src->first_insn_idx;
+	dst_state->last_insn_idx = src->last_insn_idx;
+	for (i = 0; i <= src->curframe; i++) {
+		dst = dst_state->frame[i];
+		if (!dst) {
+			dst = kzalloc(sizeof(*dst), GFP_KERNEL);
+			if (!dst)
+				return -ENOMEM;
+			dst_state->frame[i] = dst;
+		}
+		err = copy_func_state(dst, src->frame[i]);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
+static void update_branch_counts(struct bpf_verifier_env *env, struct bpf_verifier_state *st)
+{
+	while (st) {
+		u32 br = --st->branches;
+
+		/* WARN_ON(br > 1) technically makes sense here,
+		 * but see comment in push_stack(), hence:
+		 */
+		WARN_ONCE((int)br < 0,
+			  "BUG update_branch_counts:branches_to_explore=%d\n",
+			  br);
+		if (br)
+			break;
+		st = st->parent;
+	}
+}
+
+static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx,
+		     int *insn_idx, bool pop_log)
+{
+	struct bpf_verifier_state *cur = env->cur_state;
+	struct bpf_verifier_stack_elem *elem, *head = env->head;
+	int err;
+
+	if (env->head == NULL)
+		return -ENOENT;
+
+	if (cur) {
+		err = copy_verifier_state(cur, &head->st);
+		if (err)
+			return err;
+	}
+	if (pop_log)
+		bpf_vlog_reset(&env->log, head->log_pos);
+	if (insn_idx)
+		*insn_idx = head->insn_idx;
+	if (prev_insn_idx)
+		*prev_insn_idx = head->prev_insn_idx;
+	elem = head->next;
+	free_verifier_state(&head->st, false);
+	kfree(head);
+	env->head = elem;
+	env->stack_size--;
+	return 0;
+}
+
+static struct bpf_verifier_state *push_stack(struct bpf_verifier_env *env,
+					     int insn_idx, int prev_insn_idx,
+					     bool speculative)
+{
+	struct bpf_verifier_state *cur = env->cur_state;
+	struct bpf_verifier_stack_elem *elem;
+	int err;
+
+	elem = kzalloc(sizeof(struct bpf_verifier_stack_elem), GFP_KERNEL);
+	if (!elem)
+		goto err;
+
+	elem->insn_idx = insn_idx;
+	elem->prev_insn_idx = prev_insn_idx;
+	elem->next = env->head;
+	elem->log_pos = env->log.len_used;
+	env->head = elem;
+	env->stack_size++;
+	err = copy_verifier_state(&elem->st, cur);
+	if (err)
+		goto err;
+	elem->st.speculative |= speculative;
+	if (env->stack_size > BPF_COMPLEXITY_LIMIT_JMP_SEQ) {
+		verbose(env, "The sequence of %d jumps is too complex.\n",
+			env->stack_size);
+		goto err;
+	}
+	if (elem->st.parent) {
+		++elem->st.parent->branches;
+		/* WARN_ON(branches > 2) technically makes sense here,
+		 * but
+		 * 1. speculative states will bump 'branches' for non-branch
+		 * instructions
+		 * 2. is_state_visited() heuristics may decide not to create
+		 * a new state for a sequence of branches and all such current
+		 * and cloned states will be pointing to a single parent state
+		 * which might have large 'branches' count.
+		 */
+	}
+	return &elem->st;
+err:
+	free_verifier_state(env->cur_state, true);
+	env->cur_state = NULL;
+	/* pop all elements and return */
+	while (!pop_stack(env, NULL, NULL, false));
+	return NULL;
+}
+
+#define CALLER_SAVED_REGS 6
+static const int caller_saved[CALLER_SAVED_REGS] = {
+	BPF_REG_0, BPF_REG_1, BPF_REG_2, BPF_REG_3, BPF_REG_4, BPF_REG_5
+};
+
+static void __mark_reg_not_init(const struct bpf_verifier_env *env,
+				struct bpf_reg_state *reg);
+
+/* This helper doesn't clear reg->id */
+static void ___mark_reg_known(struct bpf_reg_state *reg, u64 imm)
+{
+	reg->var_off = tnum_const(imm);
+	reg->smin_value = (s64)imm;
+	reg->smax_value = (s64)imm;
+	reg->umin_value = imm;
+	reg->umax_value = imm;
+
+	reg->s32_min_value = (s32)imm;
+	reg->s32_max_value = (s32)imm;
+	reg->u32_min_value = (u32)imm;
+	reg->u32_max_value = (u32)imm;
+}
+
+/* Mark the unknown part of a register (variable offset or scalar value) as
+ * known to have the value @imm.
+ */
+static void __mark_reg_known(struct bpf_reg_state *reg, u64 imm)
+{
+	/* Clear id, off, and union(map_ptr, range) */
+	memset(((u8 *)reg) + sizeof(reg->type), 0,
+	       offsetof(struct bpf_reg_state, var_off) - sizeof(reg->type));
+	___mark_reg_known(reg, imm);
+}
+
+static void __mark_reg32_known(struct bpf_reg_state *reg, u64 imm)
+{
+	reg->var_off = tnum_const_subreg(reg->var_off, imm);
+	reg->s32_min_value = (s32)imm;
+	reg->s32_max_value = (s32)imm;
+	reg->u32_min_value = (u32)imm;
+	reg->u32_max_value = (u32)imm;
+}
+
+/* Mark the 'variable offset' part of a register as zero.  This should be
+ * used only on registers holding a pointer type.
+ */
+static void __mark_reg_known_zero(struct bpf_reg_state *reg)
+{
+	__mark_reg_known(reg, 0);
+}
+
+static void __mark_reg_const_zero(struct bpf_reg_state *reg)
+{
+	__mark_reg_known(reg, 0);
+	reg->type = SCALAR_VALUE;
+}
+
+static void mark_reg_known_zero(struct bpf_verifier_env *env,
+				struct bpf_reg_state *regs, u32 regno)
+{
+	if (WARN_ON(regno >= MAX_BPF_REG)) {
+		verbose(env, "mark_reg_known_zero(regs, %u)\n", regno);
+		/* Something bad happened, let's kill all regs */
+		for (regno = 0; regno < MAX_BPF_REG; regno++)
+			__mark_reg_not_init(env, regs + regno);
+		return;
+	}
+	__mark_reg_known_zero(regs + regno);
+}
+
+static bool reg_is_pkt_pointer(const struct bpf_reg_state *reg)
+{
+	return type_is_pkt_pointer(reg->type);
+}
+
+static bool reg_is_pkt_pointer_any(const struct bpf_reg_state *reg)
+{
+	return reg_is_pkt_pointer(reg) ||
+	       reg->type == PTR_TO_PACKET_END;
+}
+
+/* Unmodified PTR_TO_PACKET[_META,_END] register from ctx access. */
+static bool reg_is_init_pkt_pointer(const struct bpf_reg_state *reg,
+				    enum bpf_reg_type which)
+{
+	/* The register can already have a range from prior markings.
+	 * This is fine as long as it hasn't been advanced from its
+	 * origin.
+	 */
+	return reg->type == which &&
+	       reg->id == 0 &&
+	       reg->off == 0 &&
+	       tnum_equals_const(reg->var_off, 0);
+}
+
+/* Reset the min/max bounds of a register */
+static void __mark_reg_unbounded(struct bpf_reg_state *reg)
+{
+	reg->smin_value = S64_MIN;
+	reg->smax_value = S64_MAX;
+	reg->umin_value = 0;
+	reg->umax_value = U64_MAX;
+
+	reg->s32_min_value = S32_MIN;
+	reg->s32_max_value = S32_MAX;
+	reg->u32_min_value = 0;
+	reg->u32_max_value = U32_MAX;
+}
+
+static void __mark_reg64_unbounded(struct bpf_reg_state *reg)
+{
+	reg->smin_value = S64_MIN;
+	reg->smax_value = S64_MAX;
+	reg->umin_value = 0;
+	reg->umax_value = U64_MAX;
+}
+
+static void __mark_reg32_unbounded(struct bpf_reg_state *reg)
+{
+	reg->s32_min_value = S32_MIN;
+	reg->s32_max_value = S32_MAX;
+	reg->u32_min_value = 0;
+	reg->u32_max_value = U32_MAX;
+}
+
+static void __update_reg32_bounds(struct bpf_reg_state *reg)
+{
+	struct tnum var32_off = tnum_subreg(reg->var_off);
+
+	/* min signed is max(sign bit) | min(other bits) */
+	reg->s32_min_value = max_t(s32, reg->s32_min_value,
+			var32_off.value | (var32_off.mask & S32_MIN));
+	/* max signed is min(sign bit) | max(other bits) */
+	reg->s32_max_value = min_t(s32, reg->s32_max_value,
+			var32_off.value | (var32_off.mask & S32_MAX));
+	reg->u32_min_value = max_t(u32, reg->u32_min_value, (u32)var32_off.value);
+	reg->u32_max_value = min(reg->u32_max_value,
+				 (u32)(var32_off.value | var32_off.mask));
+}
+
+static void __update_reg64_bounds(struct bpf_reg_state *reg)
+{
+	/* min signed is max(sign bit) | min(other bits) */
+	reg->smin_value = max_t(s64, reg->smin_value,
+				reg->var_off.value | (reg->var_off.mask & S64_MIN));
+	/* max signed is min(sign bit) | max(other bits) */
+	reg->smax_value = min_t(s64, reg->smax_value,
+				reg->var_off.value | (reg->var_off.mask & S64_MAX));
+	reg->umin_value = max(reg->umin_value, reg->var_off.value);
+	reg->umax_value = min(reg->umax_value,
+			      reg->var_off.value | reg->var_off.mask);
+}
+
+static void __update_reg_bounds(struct bpf_reg_state *reg)
+{
+	__update_reg32_bounds(reg);
+	__update_reg64_bounds(reg);
+}
+
+/* Uses signed min/max values to inform unsigned, and vice-versa */
+static void __reg32_deduce_bounds(struct bpf_reg_state *reg)
+{
+	/* Learn sign from signed bounds.
+	 * If we cannot cross the sign boundary, then signed and unsigned bounds
+	 * are the same, so combine.  This works even in the negative case, e.g.
+	 * -3 s<= x s<= -1 implies 0xf...fd u<= x u<= 0xf...ff.
+	 */
+	if (reg->s32_min_value >= 0 || reg->s32_max_value < 0) {
+		reg->s32_min_value = reg->u32_min_value =
+			max_t(u32, reg->s32_min_value, reg->u32_min_value);
+		reg->s32_max_value = reg->u32_max_value =
+			min_t(u32, reg->s32_max_value, reg->u32_max_value);
+		return;
+	}
+	/* Learn sign from unsigned bounds.  Signed bounds cross the sign
+	 * boundary, so we must be careful.
+	 */
+	if ((s32)reg->u32_max_value >= 0) {
+		/* Positive.  We can't learn anything from the smin, but smax
+		 * is positive, hence safe.
+		 */
+		reg->s32_min_value = reg->u32_min_value;
+		reg->s32_max_value = reg->u32_max_value =
+			min_t(u32, reg->s32_max_value, reg->u32_max_value);
+	} else if ((s32)reg->u32_min_value < 0) {
+		/* Negative.  We can't learn anything from the smax, but smin
+		 * is negative, hence safe.
+		 */
+		reg->s32_min_value = reg->u32_min_value =
+			max_t(u32, reg->s32_min_value, reg->u32_min_value);
+		reg->s32_max_value = reg->u32_max_value;
+	}
+}
+
+static void __reg64_deduce_bounds(struct bpf_reg_state *reg)
+{
+	/* Learn sign from signed bounds.
+	 * If we cannot cross the sign boundary, then signed and unsigned bounds
+	 * are the same, so combine.  This works even in the negative case, e.g.
+	 * -3 s<= x s<= -1 implies 0xf...fd u<= x u<= 0xf...ff.
+	 */
+	if (reg->smin_value >= 0 || reg->smax_value < 0) {
+		reg->smin_value = reg->umin_value = max_t(u64, reg->smin_value,
+							  reg->umin_value);
+		reg->smax_value = reg->umax_value = min_t(u64, reg->smax_value,
+							  reg->umax_value);
+		return;
+	}
+	/* Learn sign from unsigned bounds.  Signed bounds cross the sign
+	 * boundary, so we must be careful.
+	 */
+	if ((s64)reg->umax_value >= 0) {
+		/* Positive.  We can't learn anything from the smin, but smax
+		 * is positive, hence safe.
+		 */
+		reg->smin_value = reg->umin_value;
+		reg->smax_value = reg->umax_value = min_t(u64, reg->smax_value,
+							  reg->umax_value);
+	} else if ((s64)reg->umin_value < 0) {
+		/* Negative.  We can't learn anything from the smax, but smin
+		 * is negative, hence safe.
+		 */
+		reg->smin_value = reg->umin_value = max_t(u64, reg->smin_value,
+							  reg->umin_value);
+		reg->smax_value = reg->umax_value;
+	}
+}
+
+static void __reg_deduce_bounds(struct bpf_reg_state *reg)
+{
+	__reg32_deduce_bounds(reg);
+	__reg64_deduce_bounds(reg);
+}
+
+/* Attempts to improve var_off based on unsigned min/max information */
+static void __reg_bound_offset(struct bpf_reg_state *reg)
+{
+	struct tnum var64_off = tnum_intersect(reg->var_off,
+					       tnum_range(reg->umin_value,
+							  reg->umax_value));
+	struct tnum var32_off = tnum_intersect(tnum_subreg(reg->var_off),
+						tnum_range(reg->u32_min_value,
+							   reg->u32_max_value));
+
+	reg->var_off = tnum_or(tnum_clear_subreg(var64_off), var32_off);
+}
+
+static void reg_bounds_sync(struct bpf_reg_state *reg)
+{
+	/* We might have learned new bounds from the var_off. */
+	__update_reg_bounds(reg);
+	/* We might have learned something about the sign bit. */
+	__reg_deduce_bounds(reg);
+	/* We might have learned some bits from the bounds. */
+	__reg_bound_offset(reg);
+	/* Intersecting with the old var_off might have improved our bounds
+	 * slightly, e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc),
+	 * then new var_off is (0; 0x7f...fc) which improves our umax.
+	 */
+	__update_reg_bounds(reg);
+}
+
+static bool __reg32_bound_s64(s32 a)
+{
+	return a >= 0 && a <= S32_MAX;
+}
+
+static void __reg_assign_32_into_64(struct bpf_reg_state *reg)
+{
+	reg->umin_value = reg->u32_min_value;
+	reg->umax_value = reg->u32_max_value;
+
+	/* Attempt to pull 32-bit signed bounds into 64-bit bounds but must
+	 * be positive otherwise set to worse case bounds and refine later
+	 * from tnum.
+	 */
+	if (__reg32_bound_s64(reg->s32_min_value) &&
+	    __reg32_bound_s64(reg->s32_max_value)) {
+		reg->smin_value = reg->s32_min_value;
+		reg->smax_value = reg->s32_max_value;
+	} else {
+		reg->smin_value = 0;
+		reg->smax_value = U32_MAX;
+	}
+}
+
+static void __reg_combine_32_into_64(struct bpf_reg_state *reg)
+{
+	/* special case when 64-bit register has upper 32-bit register
+	 * zeroed. Typically happens after zext or <<32, >>32 sequence
+	 * allowing us to use 32-bit bounds directly,
+	 */
+	if (tnum_equals_const(tnum_clear_subreg(reg->var_off), 0)) {
+		__reg_assign_32_into_64(reg);
+	} else {
+		/* Otherwise the best we can do is push lower 32bit known and
+		 * unknown bits into register (var_off set from jmp logic)
+		 * then learn as much as possible from the 64-bit tnum
+		 * known and unknown bits. The previous smin/smax bounds are
+		 * invalid here because of jmp32 compare so mark them unknown
+		 * so they do not impact tnum bounds calculation.
+		 */
+		__mark_reg64_unbounded(reg);
+	}
+	reg_bounds_sync(reg);
+}
+
+static bool __reg64_bound_s32(s64 a)
+{
+	return a >= S32_MIN && a <= S32_MAX;
+}
+
+static bool __reg64_bound_u32(u64 a)
+{
+	return a >= U32_MIN && a <= U32_MAX;
+}
+
+static void __reg_combine_64_into_32(struct bpf_reg_state *reg)
+{
+	__mark_reg32_unbounded(reg);
+	if (__reg64_bound_s32(reg->smin_value) && __reg64_bound_s32(reg->smax_value)) {
+		reg->s32_min_value = (s32)reg->smin_value;
+		reg->s32_max_value = (s32)reg->smax_value;
+	}
+	if (__reg64_bound_u32(reg->umin_value) && __reg64_bound_u32(reg->umax_value)) {
+		reg->u32_min_value = (u32)reg->umin_value;
+		reg->u32_max_value = (u32)reg->umax_value;
+	}
+	reg_bounds_sync(reg);
+}
+
+/* Mark a register as having a completely unknown (scalar) value. */
+static void __mark_reg_unknown(const struct bpf_verifier_env *env,
+			       struct bpf_reg_state *reg)
+{
+	/*
+	 * Clear type, id, off, and union(map_ptr, range) and
+	 * padding between 'type' and union
+	 */
+	memset(reg, 0, offsetof(struct bpf_reg_state, var_off));
+	reg->type = SCALAR_VALUE;
+	reg->var_off = tnum_unknown;
+	reg->frameno = 0;
+	reg->precise = !env->bpf_capable;
+	__mark_reg_unbounded(reg);
+}
+
+static void mark_reg_unknown(struct bpf_verifier_env *env,
+			     struct bpf_reg_state *regs, u32 regno)
+{
+	if (WARN_ON(regno >= MAX_BPF_REG)) {
+		verbose(env, "mark_reg_unknown(regs, %u)\n", regno);
+		/* Something bad happened, let's kill all regs except FP */
+		for (regno = 0; regno < BPF_REG_FP; regno++)
+			__mark_reg_not_init(env, regs + regno);
+		return;
+	}
+	__mark_reg_unknown(env, regs + regno);
+}
+
+static void __mark_reg_not_init(const struct bpf_verifier_env *env,
+				struct bpf_reg_state *reg)
+{
+	__mark_reg_unknown(env, reg);
+	reg->type = NOT_INIT;
+}
+
+static void mark_reg_not_init(struct bpf_verifier_env *env,
+			      struct bpf_reg_state *regs, u32 regno)
+{
+	if (WARN_ON(regno >= MAX_BPF_REG)) {
+		verbose(env, "mark_reg_not_init(regs, %u)\n", regno);
+		/* Something bad happened, let's kill all regs except FP */
+		for (regno = 0; regno < BPF_REG_FP; regno++)
+			__mark_reg_not_init(env, regs + regno);
+		return;
+	}
+	__mark_reg_not_init(env, regs + regno);
+}
+
+static void mark_btf_ld_reg(struct bpf_verifier_env *env,
+			    struct bpf_reg_state *regs, u32 regno,
+			    enum bpf_reg_type reg_type, u32 btf_id)
+{
+	if (reg_type == SCALAR_VALUE) {
+		mark_reg_unknown(env, regs, regno);
+		return;
+	}
+	mark_reg_known_zero(env, regs, regno);
+	regs[regno].type = PTR_TO_BTF_ID;
+	regs[regno].btf_id = btf_id;
+}
+
+#define DEF_NOT_SUBREG	(0)
+static void init_reg_state(struct bpf_verifier_env *env,
+			   struct bpf_func_state *state)
+{
+	struct bpf_reg_state *regs = state->regs;
+	int i;
+
+	for (i = 0; i < MAX_BPF_REG; i++) {
+		mark_reg_not_init(env, regs, i);
+		regs[i].live = REG_LIVE_NONE;
+		regs[i].parent = NULL;
+		regs[i].subreg_def = DEF_NOT_SUBREG;
+	}
+
+	/* frame pointer */
+	regs[BPF_REG_FP].type = PTR_TO_STACK;
+	mark_reg_known_zero(env, regs, BPF_REG_FP);
+	regs[BPF_REG_FP].frameno = state->frameno;
+}
+
+#define BPF_MAIN_FUNC (-1)
+static void init_func_state(struct bpf_verifier_env *env,
+			    struct bpf_func_state *state,
+			    int callsite, int frameno, int subprogno)
+{
+	state->callsite = callsite;
+	state->frameno = frameno;
+	state->subprogno = subprogno;
+	init_reg_state(env, state);
+}
+
+enum reg_arg_type {
+	SRC_OP,		/* register is used as source operand */
+	DST_OP,		/* register is used as destination operand */
+	DST_OP_NO_MARK	/* same as above, check only, don't mark */
+};
+
+static int cmp_subprogs(const void *a, const void *b)
+{
+	return ((struct bpf_subprog_info *)a)->start -
+	       ((struct bpf_subprog_info *)b)->start;
+}
+
+static int find_subprog(struct bpf_verifier_env *env, int off)
+{
+	struct bpf_subprog_info *p;
+
+	p = bsearch(&off, env->subprog_info, env->subprog_cnt,
+		    sizeof(env->subprog_info[0]), cmp_subprogs);
+	if (!p)
+		return -ENOENT;
+	return p - env->subprog_info;
+
+}
+
+static int add_subprog(struct bpf_verifier_env *env, int off)
+{
+	int insn_cnt = env->prog->len;
+	int ret;
+
+	if (off >= insn_cnt || off < 0) {
+		verbose(env, "call to invalid destination\n");
+		return -EINVAL;
+	}
+	ret = find_subprog(env, off);
+	if (ret >= 0)
+		return 0;
+	if (env->subprog_cnt >= BPF_MAX_SUBPROGS) {
+		verbose(env, "too many subprograms\n");
+		return -E2BIG;
+	}
+	env->subprog_info[env->subprog_cnt++].start = off;
+	sort(env->subprog_info, env->subprog_cnt,
+	     sizeof(env->subprog_info[0]), cmp_subprogs, NULL);
+	return 0;
+}
+
+static int check_subprogs(struct bpf_verifier_env *env)
+{
+	int i, ret, subprog_start, subprog_end, off, cur_subprog = 0;
+	struct bpf_subprog_info *subprog = env->subprog_info;
+	struct bpf_insn *insn = env->prog->insnsi;
+	int insn_cnt = env->prog->len;
+
+	/* Add entry function. */
+	ret = add_subprog(env, 0);
+	if (ret < 0)
+		return ret;
+
+	/* determine subprog starts. The end is one before the next starts */
+	for (i = 0; i < insn_cnt; i++) {
+		if (insn[i].code != (BPF_JMP | BPF_CALL))
+			continue;
+		if (insn[i].src_reg != BPF_PSEUDO_CALL)
+			continue;
+		if (!env->bpf_capable) {
+			verbose(env,
+				"function calls to other bpf functions are allowed for CAP_BPF and CAP_SYS_ADMIN\n");
+			return -EPERM;
+		}
+		ret = add_subprog(env, i + insn[i].imm + 1);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Add a fake 'exit' subprog which could simplify subprog iteration
+	 * logic. 'subprog_cnt' should not be increased.
+	 */
+	subprog[env->subprog_cnt].start = insn_cnt;
+
+	if (env->log.level & BPF_LOG_LEVEL2)
+		for (i = 0; i < env->subprog_cnt; i++)
+			verbose(env, "func#%d @%d\n", i, subprog[i].start);
+
+	/* now check that all jumps are within the same subprog */
+	subprog_start = subprog[cur_subprog].start;
+	subprog_end = subprog[cur_subprog + 1].start;
+	for (i = 0; i < insn_cnt; i++) {
+		u8 code = insn[i].code;
+
+		if (code == (BPF_JMP | BPF_CALL) &&
+		    insn[i].imm == BPF_FUNC_tail_call &&
+		    insn[i].src_reg != BPF_PSEUDO_CALL)
+			subprog[cur_subprog].has_tail_call = true;
+		if (BPF_CLASS(code) == BPF_LD &&
+		    (BPF_MODE(code) == BPF_ABS || BPF_MODE(code) == BPF_IND))
+			subprog[cur_subprog].has_ld_abs = true;
+		if (BPF_CLASS(code) != BPF_JMP && BPF_CLASS(code) != BPF_JMP32)
+			goto next;
+		if (BPF_OP(code) == BPF_EXIT || BPF_OP(code) == BPF_CALL)
+			goto next;
+		off = i + insn[i].off + 1;
+		if (off < subprog_start || off >= subprog_end) {
+			verbose(env, "jump out of range from insn %d to %d\n", i, off);
+			return -EINVAL;
+		}
+next:
+		if (i == subprog_end - 1) {
+			/* to avoid fall-through from one subprog into another
+			 * the last insn of the subprog should be either exit
+			 * or unconditional jump back
+			 */
+			if (code != (BPF_JMP | BPF_EXIT) &&
+			    code != (BPF_JMP | BPF_JA)) {
+				verbose(env, "last insn is not an exit or jmp\n");
+				return -EINVAL;
+			}
+			subprog_start = subprog_end;
+			cur_subprog++;
+			if (cur_subprog < env->subprog_cnt)
+				subprog_end = subprog[cur_subprog + 1].start;
+		}
+	}
+	return 0;
+}
+
+/* Parentage chain of this register (or stack slot) should take care of all
+ * issues like callee-saved registers, stack slot allocation time, etc.
+ */
+static int mark_reg_read(struct bpf_verifier_env *env,
+			 const struct bpf_reg_state *state,
+			 struct bpf_reg_state *parent, u8 flag)
+{
+	bool writes = parent == state->parent; /* Observe write marks */
+	int cnt = 0;
+
+	while (parent) {
+		/* if read wasn't screened by an earlier write ... */
+		if (writes && state->live & REG_LIVE_WRITTEN)
+			break;
+		if (parent->live & REG_LIVE_DONE) {
+			verbose(env, "verifier BUG type %s var_off %lld off %d\n",
+				reg_type_str[parent->type],
+				parent->var_off.value, parent->off);
+			return -EFAULT;
+		}
+		/* The first condition is more likely to be true than the
+		 * second, checked it first.
+		 */
+		if ((parent->live & REG_LIVE_READ) == flag ||
+		    parent->live & REG_LIVE_READ64)
+			/* The parentage chain never changes and
+			 * this parent was already marked as LIVE_READ.
+			 * There is no need to keep walking the chain again and
+			 * keep re-marking all parents as LIVE_READ.
+			 * This case happens when the same register is read
+			 * multiple times without writes into it in-between.
+			 * Also, if parent has the stronger REG_LIVE_READ64 set,
+			 * then no need to set the weak REG_LIVE_READ32.
+			 */
+			break;
+		/* ... then we depend on parent's value */
+		parent->live |= flag;
+		/* REG_LIVE_READ64 overrides REG_LIVE_READ32. */
+		if (flag == REG_LIVE_READ64)
+			parent->live &= ~REG_LIVE_READ32;
+		state = parent;
+		parent = state->parent;
+		writes = true;
+		cnt++;
+	}
+
+	if (env->longest_mark_read_walk < cnt)
+		env->longest_mark_read_walk = cnt;
+	return 0;
+}
+
+/* This function is supposed to be used by the following 32-bit optimization
+ * code only. It returns TRUE if the source or destination register operates
+ * on 64-bit, otherwise return FALSE.
+ */
+static bool is_reg64(struct bpf_verifier_env *env, struct bpf_insn *insn,
+		     u32 regno, struct bpf_reg_state *reg, enum reg_arg_type t)
+{
+	u8 code, class, op;
+
+	code = insn->code;
+	class = BPF_CLASS(code);
+	op = BPF_OP(code);
+	if (class == BPF_JMP) {
+		/* BPF_EXIT for "main" will reach here. Return TRUE
+		 * conservatively.
+		 */
+		if (op == BPF_EXIT)
+			return true;
+		if (op == BPF_CALL) {
+			/* BPF to BPF call will reach here because of marking
+			 * caller saved clobber with DST_OP_NO_MARK for which we
+			 * don't care the register def because they are anyway
+			 * marked as NOT_INIT already.
+			 */
+			if (insn->src_reg == BPF_PSEUDO_CALL)
+				return false;
+			/* Helper call will reach here because of arg type
+			 * check, conservatively return TRUE.
+			 */
+			if (t == SRC_OP)
+				return true;
+
+			return false;
+		}
+	}
+
+	if (class == BPF_ALU64 || class == BPF_JMP ||
+	    /* BPF_END always use BPF_ALU class. */
+	    (class == BPF_ALU && op == BPF_END && insn->imm == 64))
+		return true;
+
+	if (class == BPF_ALU || class == BPF_JMP32)
+		return false;
+
+	if (class == BPF_LDX) {
+		if (t != SRC_OP)
+			return BPF_SIZE(code) == BPF_DW;
+		/* LDX source must be ptr. */
+		return true;
+	}
+
+	if (class == BPF_STX) {
+		if (reg->type != SCALAR_VALUE)
+			return true;
+		return BPF_SIZE(code) == BPF_DW;
+	}
+
+	if (class == BPF_LD) {
+		u8 mode = BPF_MODE(code);
+
+		/* LD_IMM64 */
+		if (mode == BPF_IMM)
+			return true;
+
+		/* Both LD_IND and LD_ABS return 32-bit data. */
+		if (t != SRC_OP)
+			return  false;
+
+		/* Implicit ctx ptr. */
+		if (regno == BPF_REG_6)
+			return true;
+
+		/* Explicit source could be any width. */
+		return true;
+	}
+
+	if (class == BPF_ST)
+		/* The only source register for BPF_ST is a ptr. */
+		return true;
+
+	/* Conservatively return true at default. */
+	return true;
+}
+
+/* Return TRUE if INSN doesn't have explicit value define. */
+static bool insn_no_def(struct bpf_insn *insn)
+{
+	u8 class = BPF_CLASS(insn->code);
+
+	return (class == BPF_JMP || class == BPF_JMP32 ||
+		class == BPF_STX || class == BPF_ST);
+}
+
+/* Return TRUE if INSN has defined any 32-bit value explicitly. */
+static bool insn_has_def32(struct bpf_verifier_env *env, struct bpf_insn *insn)
+{
+	if (insn_no_def(insn))
+		return false;
+
+	return !is_reg64(env, insn, insn->dst_reg, NULL, DST_OP);
+}
+
+static void mark_insn_zext(struct bpf_verifier_env *env,
+			   struct bpf_reg_state *reg)
+{
+	s32 def_idx = reg->subreg_def;
+
+	if (def_idx == DEF_NOT_SUBREG)
+		return;
+
+	env->insn_aux_data[def_idx - 1].zext_dst = true;
+	/* The dst will be zero extended, so won't be sub-register anymore. */
+	reg->subreg_def = DEF_NOT_SUBREG;
+}
+
+static int check_reg_arg(struct bpf_verifier_env *env, u32 regno,
+			 enum reg_arg_type t)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	struct bpf_insn *insn = env->prog->insnsi + env->insn_idx;
+	struct bpf_reg_state *reg, *regs = state->regs;
+	bool rw64;
+
+	if (regno >= MAX_BPF_REG) {
+		verbose(env, "R%d is invalid\n", regno);
+		return -EINVAL;
+	}
+
+	reg = &regs[regno];
+	rw64 = is_reg64(env, insn, regno, reg, t);
+	if (t == SRC_OP) {
+		/* check whether register used as source operand can be read */
+		if (reg->type == NOT_INIT) {
+			verbose(env, "R%d !read_ok\n", regno);
+			return -EACCES;
+		}
+		/* We don't need to worry about FP liveness because it's read-only */
+		if (regno == BPF_REG_FP)
+			return 0;
+
+		if (rw64)
+			mark_insn_zext(env, reg);
+
+		return mark_reg_read(env, reg, reg->parent,
+				     rw64 ? REG_LIVE_READ64 : REG_LIVE_READ32);
+	} else {
+		/* check whether register used as dest operand can be written to */
+		if (regno == BPF_REG_FP) {
+			verbose(env, "frame pointer is read only\n");
+			return -EACCES;
+		}
+		reg->live |= REG_LIVE_WRITTEN;
+		reg->subreg_def = rw64 ? DEF_NOT_SUBREG : env->insn_idx + 1;
+		if (t == DST_OP)
+			mark_reg_unknown(env, regs, regno);
+	}
+	return 0;
+}
+
+/* for any branch, call, exit record the history of jmps in the given state */
+static int push_jmp_history(struct bpf_verifier_env *env,
+			    struct bpf_verifier_state *cur)
+{
+	u32 cnt = cur->jmp_history_cnt;
+	struct bpf_idx_pair *p;
+
+	cnt++;
+	p = krealloc(cur->jmp_history, cnt * sizeof(*p), GFP_USER);
+	if (!p)
+		return -ENOMEM;
+	p[cnt - 1].idx = env->insn_idx;
+	p[cnt - 1].prev_idx = env->prev_insn_idx;
+	cur->jmp_history = p;
+	cur->jmp_history_cnt = cnt;
+	return 0;
+}
+
+/* Backtrack one insn at a time. If idx is not at the top of recorded
+ * history then previous instruction came from straight line execution.
+ */
+static int get_prev_insn_idx(struct bpf_verifier_state *st, int i,
+			     u32 *history)
+{
+	u32 cnt = *history;
+
+	if (cnt && st->jmp_history[cnt - 1].idx == i) {
+		i = st->jmp_history[cnt - 1].prev_idx;
+		(*history)--;
+	} else {
+		i--;
+	}
+	return i;
+}
+
+/* For given verifier state backtrack_insn() is called from the last insn to
+ * the first insn. Its purpose is to compute a bitmask of registers and
+ * stack slots that needs precision in the parent verifier state.
+ */
+static int backtrack_insn(struct bpf_verifier_env *env, int idx,
+			  u32 *reg_mask, u64 *stack_mask)
+{
+	const struct bpf_insn_cbs cbs = {
+		.cb_print	= verbose,
+		.private_data	= env,
+	};
+	struct bpf_insn *insn = env->prog->insnsi + idx;
+	u8 class = BPF_CLASS(insn->code);
+	u8 opcode = BPF_OP(insn->code);
+	u8 mode = BPF_MODE(insn->code);
+	u32 dreg = 1u << insn->dst_reg;
+	u32 sreg = 1u << insn->src_reg;
+	u32 spi;
+
+	if (insn->code == 0)
+		return 0;
+	if (env->log.level & BPF_LOG_LEVEL) {
+		verbose(env, "regs=%x stack=%llx before ", *reg_mask, *stack_mask);
+		verbose(env, "%d: ", idx);
+		print_bpf_insn(&cbs, insn, env->allow_ptr_leaks);
+	}
+
+	if (class == BPF_ALU || class == BPF_ALU64) {
+		if (!(*reg_mask & dreg))
+			return 0;
+		if (opcode == BPF_END || opcode == BPF_NEG) {
+			/* sreg is reserved and unused
+			 * dreg still need precision before this insn
+			 */
+			return 0;
+		} else if (opcode == BPF_MOV) {
+			if (BPF_SRC(insn->code) == BPF_X) {
+				/* dreg = sreg
+				 * dreg needs precision after this insn
+				 * sreg needs precision before this insn
+				 */
+				*reg_mask &= ~dreg;
+				*reg_mask |= sreg;
+			} else {
+				/* dreg = K
+				 * dreg needs precision after this insn.
+				 * Corresponding register is already marked
+				 * as precise=true in this verifier state.
+				 * No further markings in parent are necessary
+				 */
+				*reg_mask &= ~dreg;
+			}
+		} else {
+			if (BPF_SRC(insn->code) == BPF_X) {
+				/* dreg += sreg
+				 * both dreg and sreg need precision
+				 * before this insn
+				 */
+				*reg_mask |= sreg;
+			} /* else dreg += K
+			   * dreg still needs precision before this insn
+			   */
+		}
+	} else if (class == BPF_LDX) {
+		if (!(*reg_mask & dreg))
+			return 0;
+		*reg_mask &= ~dreg;
+
+		/* scalars can only be spilled into stack w/o losing precision.
+		 * Load from any other memory can be zero extended.
+		 * The desire to keep that precision is already indicated
+		 * by 'precise' mark in corresponding register of this state.
+		 * No further tracking necessary.
+		 */
+		if (insn->src_reg != BPF_REG_FP)
+			return 0;
+
+		/* dreg = *(u64 *)[fp - off] was a fill from the stack.
+		 * that [fp - off] slot contains scalar that needs to be
+		 * tracked with precision
+		 */
+		spi = (-insn->off - 1) / BPF_REG_SIZE;
+		if (spi >= 64) {
+			verbose(env, "BUG spi %d\n", spi);
+			WARN_ONCE(1, "verifier backtracking bug");
+			return -EFAULT;
+		}
+		*stack_mask |= 1ull << spi;
+	} else if (class == BPF_STX || class == BPF_ST) {
+		if (*reg_mask & dreg)
+			/* stx & st shouldn't be using _scalar_ dst_reg
+			 * to access memory. It means backtracking
+			 * encountered a case of pointer subtraction.
+			 */
+			return -ENOTSUPP;
+		/* scalars can only be spilled into stack */
+		if (insn->dst_reg != BPF_REG_FP)
+			return 0;
+		spi = (-insn->off - 1) / BPF_REG_SIZE;
+		if (spi >= 64) {
+			verbose(env, "BUG spi %d\n", spi);
+			WARN_ONCE(1, "verifier backtracking bug");
+			return -EFAULT;
+		}
+		if (!(*stack_mask & (1ull << spi)))
+			return 0;
+		*stack_mask &= ~(1ull << spi);
+		if (class == BPF_STX)
+			*reg_mask |= sreg;
+	} else if (class == BPF_JMP || class == BPF_JMP32) {
+		if (opcode == BPF_CALL) {
+			if (insn->src_reg == BPF_PSEUDO_CALL)
+				return -ENOTSUPP;
+			/* regular helper call sets R0 */
+			*reg_mask &= ~1;
+			if (*reg_mask & 0x3f) {
+				/* if backtracing was looking for registers R1-R5
+				 * they should have been found already.
+				 */
+				verbose(env, "BUG regs %x\n", *reg_mask);
+				WARN_ONCE(1, "verifier backtracking bug");
+				return -EFAULT;
+			}
+		} else if (opcode == BPF_EXIT) {
+			return -ENOTSUPP;
+		} else if (BPF_SRC(insn->code) == BPF_X) {
+			if (!(*reg_mask & (dreg | sreg)))
+				return 0;
+			/* dreg <cond> sreg
+			 * Both dreg and sreg need precision before
+			 * this insn. If only sreg was marked precise
+			 * before it would be equally necessary to
+			 * propagate it to dreg.
+			 */
+			*reg_mask |= (sreg | dreg);
+			 /* else dreg <cond> K
+			  * Only dreg still needs precision before
+			  * this insn, so for the K-based conditional
+			  * there is nothing new to be marked.
+			  */
+		}
+	} else if (class == BPF_LD) {
+		if (!(*reg_mask & dreg))
+			return 0;
+		*reg_mask &= ~dreg;
+		/* It's ld_imm64 or ld_abs or ld_ind.
+		 * For ld_imm64 no further tracking of precision
+		 * into parent is necessary
+		 */
+		if (mode == BPF_IND || mode == BPF_ABS)
+			/* to be analyzed */
+			return -ENOTSUPP;
+	}
+	return 0;
+}
+
+/* the scalar precision tracking algorithm:
+ * . at the start all registers have precise=false.
+ * . scalar ranges are tracked as normal through alu and jmp insns.
+ * . once precise value of the scalar register is used in:
+ *   .  ptr + scalar alu
+ *   . if (scalar cond K|scalar)
+ *   .  helper_call(.., scalar, ...) where ARG_CONST is expected
+ *   backtrack through the verifier states and mark all registers and
+ *   stack slots with spilled constants that these scalar regisers
+ *   should be precise.
+ * . during state pruning two registers (or spilled stack slots)
+ *   are equivalent if both are not precise.
+ *
+ * Note the verifier cannot simply walk register parentage chain,
+ * since many different registers and stack slots could have been
+ * used to compute single precise scalar.
+ *
+ * The approach of starting with precise=true for all registers and then
+ * backtrack to mark a register as not precise when the verifier detects
+ * that program doesn't care about specific value (e.g., when helper
+ * takes register as ARG_ANYTHING parameter) is not safe.
+ *
+ * It's ok to walk single parentage chain of the verifier states.
+ * It's possible that this backtracking will go all the way till 1st insn.
+ * All other branches will be explored for needing precision later.
+ *
+ * The backtracking needs to deal with cases like:
+ *   R8=map_value(id=0,off=0,ks=4,vs=1952,imm=0) R9_w=map_value(id=0,off=40,ks=4,vs=1952,imm=0)
+ * r9 -= r8
+ * r5 = r9
+ * if r5 > 0x79f goto pc+7
+ *    R5_w=inv(id=0,umax_value=1951,var_off=(0x0; 0x7ff))
+ * r5 += 1
+ * ...
+ * call bpf_perf_event_output#25
+ *   where .arg5_type = ARG_CONST_SIZE_OR_ZERO
+ *
+ * and this case:
+ * r6 = 1
+ * call foo // uses callee's r6 inside to compute r0
+ * r0 += r6
+ * if r0 == 0 goto
+ *
+ * to track above reg_mask/stack_mask needs to be independent for each frame.
+ *
+ * Also if parent's curframe > frame where backtracking started,
+ * the verifier need to mark registers in both frames, otherwise callees
+ * may incorrectly prune callers. This is similar to
+ * commit 7640ead93924 ("bpf: verifier: make sure callees don't prune with caller differences")
+ *
+ * For now backtracking falls back into conservative marking.
+ */
+static void mark_all_scalars_precise(struct bpf_verifier_env *env,
+				     struct bpf_verifier_state *st)
+{
+	struct bpf_func_state *func;
+	struct bpf_reg_state *reg;
+	int i, j;
+
+	/* big hammer: mark all scalars precise in this path.
+	 * pop_stack may still get !precise scalars.
+	 * We also skip current state and go straight to first parent state,
+	 * because precision markings in current non-checkpointed state are
+	 * not needed. See why in the comment in __mark_chain_precision below.
+	 */
+	for (st = st->parent; st; st = st->parent) {
+		for (i = 0; i <= st->curframe; i++) {
+			func = st->frame[i];
+			for (j = 0; j < BPF_REG_FP; j++) {
+				reg = &func->regs[j];
+				if (reg->type != SCALAR_VALUE)
+					continue;
+				reg->precise = true;
+			}
+			for (j = 0; j < func->allocated_stack / BPF_REG_SIZE; j++) {
+				if (!is_spilled_reg(&func->stack[j]))
+					continue;
+				reg = &func->stack[j].spilled_ptr;
+				if (reg->type != SCALAR_VALUE)
+					continue;
+				reg->precise = true;
+			}
+		}
+	}
+}
+
+static void mark_all_scalars_imprecise(struct bpf_verifier_env *env, struct bpf_verifier_state *st)
+{
+	struct bpf_func_state *func;
+	struct bpf_reg_state *reg;
+	int i, j;
+
+	for (i = 0; i <= st->curframe; i++) {
+		func = st->frame[i];
+		for (j = 0; j < BPF_REG_FP; j++) {
+			reg = &func->regs[j];
+			if (reg->type != SCALAR_VALUE)
+				continue;
+			reg->precise = false;
+		}
+		for (j = 0; j < func->allocated_stack / BPF_REG_SIZE; j++) {
+			if (!is_spilled_reg(&func->stack[j]))
+				continue;
+			reg = &func->stack[j].spilled_ptr;
+			if (reg->type != SCALAR_VALUE)
+				continue;
+			reg->precise = false;
+		}
+	}
+}
+
+/*
+ * __mark_chain_precision() backtracks BPF program instruction sequence and
+ * chain of verifier states making sure that register *regno* (if regno >= 0)
+ * and/or stack slot *spi* (if spi >= 0) are marked as precisely tracked
+ * SCALARS, as well as any other registers and slots that contribute to
+ * a tracked state of given registers/stack slots, depending on specific BPF
+ * assembly instructions (see backtrack_insns() for exact instruction handling
+ * logic). This backtracking relies on recorded jmp_history and is able to
+ * traverse entire chain of parent states. This process ends only when all the
+ * necessary registers/slots and their transitive dependencies are marked as
+ * precise.
+ *
+ * One important and subtle aspect is that precise marks *do not matter* in
+ * the currently verified state (current state). It is important to understand
+ * why this is the case.
+ *
+ * First, note that current state is the state that is not yet "checkpointed",
+ * i.e., it is not yet put into env->explored_states, and it has no children
+ * states as well. It's ephemeral, and can end up either a) being discarded if
+ * compatible explored state is found at some point or BPF_EXIT instruction is
+ * reached or b) checkpointed and put into env->explored_states, branching out
+ * into one or more children states.
+ *
+ * In the former case, precise markings in current state are completely
+ * ignored by state comparison code (see regsafe() for details). Only
+ * checkpointed ("old") state precise markings are important, and if old
+ * state's register/slot is precise, regsafe() assumes current state's
+ * register/slot as precise and checks value ranges exactly and precisely. If
+ * states turn out to be compatible, current state's necessary precise
+ * markings and any required parent states' precise markings are enforced
+ * after the fact with propagate_precision() logic, after the fact. But it's
+ * important to realize that in this case, even after marking current state
+ * registers/slots as precise, we immediately discard current state. So what
+ * actually matters is any of the precise markings propagated into current
+ * state's parent states, which are always checkpointed (due to b) case above).
+ * As such, for scenario a) it doesn't matter if current state has precise
+ * markings set or not.
+ *
+ * Now, for the scenario b), checkpointing and forking into child(ren)
+ * state(s). Note that before current state gets to checkpointing step, any
+ * processed instruction always assumes precise SCALAR register/slot
+ * knowledge: if precise value or range is useful to prune jump branch, BPF
+ * verifier takes this opportunity enthusiastically. Similarly, when
+ * register's value is used to calculate offset or memory address, exact
+ * knowledge of SCALAR range is assumed, checked, and enforced. So, similar to
+ * what we mentioned above about state comparison ignoring precise markings
+ * during state comparison, BPF verifier ignores and also assumes precise
+ * markings *at will* during instruction verification process. But as verifier
+ * assumes precision, it also propagates any precision dependencies across
+ * parent states, which are not yet finalized, so can be further restricted
+ * based on new knowledge gained from restrictions enforced by their children
+ * states. This is so that once those parent states are finalized, i.e., when
+ * they have no more active children state, state comparison logic in
+ * is_state_visited() would enforce strict and precise SCALAR ranges, if
+ * required for correctness.
+ *
+ * To build a bit more intuition, note also that once a state is checkpointed,
+ * the path we took to get to that state is not important. This is crucial
+ * property for state pruning. When state is checkpointed and finalized at
+ * some instruction index, it can be correctly and safely used to "short
+ * circuit" any *compatible* state that reaches exactly the same instruction
+ * index. I.e., if we jumped to that instruction from a completely different
+ * code path than original finalized state was derived from, it doesn't
+ * matter, current state can be discarded because from that instruction
+ * forward having a compatible state will ensure we will safely reach the
+ * exit. States describe preconditions for further exploration, but completely
+ * forget the history of how we got here.
+ *
+ * This also means that even if we needed precise SCALAR range to get to
+ * finalized state, but from that point forward *that same* SCALAR register is
+ * never used in a precise context (i.e., it's precise value is not needed for
+ * correctness), it's correct and safe to mark such register as "imprecise"
+ * (i.e., precise marking set to false). This is what we rely on when we do
+ * not set precise marking in current state. If no child state requires
+ * precision for any given SCALAR register, it's safe to dictate that it can
+ * be imprecise. If any child state does require this register to be precise,
+ * we'll mark it precise later retroactively during precise markings
+ * propagation from child state to parent states.
+ *
+ * Skipping precise marking setting in current state is a mild version of
+ * relying on the above observation. But we can utilize this property even
+ * more aggressively by proactively forgetting any precise marking in the
+ * current state (which we inherited from the parent state), right before we
+ * checkpoint it and branch off into new child state. This is done by
+ * mark_all_scalars_imprecise() to hopefully get more permissive and generic
+ * finalized states which help in short circuiting more future states.
+ */
+static int __mark_chain_precision(struct bpf_verifier_env *env, int frame, int regno,
+				  int spi)
+{
+	struct bpf_verifier_state *st = env->cur_state;
+	int first_idx = st->first_insn_idx;
+	int last_idx = env->insn_idx;
+	struct bpf_func_state *func;
+	struct bpf_reg_state *reg;
+	u32 reg_mask = regno >= 0 ? 1u << regno : 0;
+	u64 stack_mask = spi >= 0 ? 1ull << spi : 0;
+	bool skip_first = true;
+	bool new_marks = false;
+	int i, err;
+
+	if (!env->bpf_capable)
+		return 0;
+
+	/* Do sanity checks against current state of register and/or stack
+	 * slot, but don't set precise flag in current state, as precision
+	 * tracking in the current state is unnecessary.
+	 */
+	func = st->frame[frame];
+	if (regno >= 0) {
+		reg = &func->regs[regno];
+		if (reg->type != SCALAR_VALUE) {
+			WARN_ONCE(1, "backtracing misuse");
+			return -EFAULT;
+		}
+		new_marks = true;
+	}
+
+	while (spi >= 0) {
+		if (!is_spilled_reg(&func->stack[spi])) {
+			stack_mask = 0;
+			break;
+		}
+		reg = &func->stack[spi].spilled_ptr;
+		if (reg->type != SCALAR_VALUE) {
+			stack_mask = 0;
+			break;
+		}
+		new_marks = true;
+		break;
+	}
+
+	if (!new_marks)
+		return 0;
+	if (!reg_mask && !stack_mask)
+		return 0;
+
+	for (;;) {
+		DECLARE_BITMAP(mask, 64);
+		u32 history = st->jmp_history_cnt;
+
+		if (env->log.level & BPF_LOG_LEVEL)
+			verbose(env, "last_idx %d first_idx %d\n", last_idx, first_idx);
+
+		if (last_idx < 0) {
+			/* we are at the entry into subprog, which
+			 * is expected for global funcs, but only if
+			 * requested precise registers are R1-R5
+			 * (which are global func's input arguments)
+			 */
+			if (st->curframe == 0 &&
+			    st->frame[0]->subprogno > 0 &&
+			    st->frame[0]->callsite == BPF_MAIN_FUNC &&
+			    stack_mask == 0 && (reg_mask & ~0x3e) == 0) {
+				bitmap_from_u64(mask, reg_mask);
+				for_each_set_bit(i, mask, 32) {
+					reg = &st->frame[0]->regs[i];
+					if (reg->type != SCALAR_VALUE) {
+						reg_mask &= ~(1u << i);
+						continue;
+					}
+					reg->precise = true;
+				}
+				return 0;
+			}
+
+			verbose(env, "BUG backtracing func entry subprog %d reg_mask %x stack_mask %llx\n",
+				st->frame[0]->subprogno, reg_mask, stack_mask);
+			WARN_ONCE(1, "verifier backtracking bug");
+			return -EFAULT;
+		}
+
+		for (i = last_idx;;) {
+			if (skip_first) {
+				err = 0;
+				skip_first = false;
+			} else {
+				err = backtrack_insn(env, i, &reg_mask, &stack_mask);
+			}
+			if (err == -ENOTSUPP) {
+				mark_all_scalars_precise(env, st);
+				return 0;
+			} else if (err) {
+				return err;
+			}
+			if (!reg_mask && !stack_mask)
+				/* Found assignment(s) into tracked register in this state.
+				 * Since this state is already marked, just return.
+				 * Nothing to be tracked further in the parent state.
+				 */
+				return 0;
+			if (i == first_idx)
+				break;
+			i = get_prev_insn_idx(st, i, &history);
+			if (i >= env->prog->len) {
+				/* This can happen if backtracking reached insn 0
+				 * and there are still reg_mask or stack_mask
+				 * to backtrack.
+				 * It means the backtracking missed the spot where
+				 * particular register was initialized with a constant.
+				 */
+				verbose(env, "BUG backtracking idx %d\n", i);
+				WARN_ONCE(1, "verifier backtracking bug");
+				return -EFAULT;
+			}
+		}
+		st = st->parent;
+		if (!st)
+			break;
+
+		new_marks = false;
+		func = st->frame[frame];
+		bitmap_from_u64(mask, reg_mask);
+		for_each_set_bit(i, mask, 32) {
+			reg = &func->regs[i];
+			if (reg->type != SCALAR_VALUE) {
+				reg_mask &= ~(1u << i);
+				continue;
+			}
+			if (!reg->precise)
+				new_marks = true;
+			reg->precise = true;
+		}
+
+		bitmap_from_u64(mask, stack_mask);
+		for_each_set_bit(i, mask, 64) {
+			if (i >= func->allocated_stack / BPF_REG_SIZE) {
+				/* the sequence of instructions:
+				 * 2: (bf) r3 = r10
+				 * 3: (7b) *(u64 *)(r3 -8) = r0
+				 * 4: (79) r4 = *(u64 *)(r10 -8)
+				 * doesn't contain jmps. It's backtracked
+				 * as a single block.
+				 * During backtracking insn 3 is not recognized as
+				 * stack access, so at the end of backtracking
+				 * stack slot fp-8 is still marked in stack_mask.
+				 * However the parent state may not have accessed
+				 * fp-8 and it's "unallocated" stack space.
+				 * In such case fallback to conservative.
+				 */
+				mark_all_scalars_precise(env, st);
+				return 0;
+			}
+
+			if (!is_spilled_reg(&func->stack[i])) {
+				stack_mask &= ~(1ull << i);
+				continue;
+			}
+			reg = &func->stack[i].spilled_ptr;
+			if (reg->type != SCALAR_VALUE) {
+				stack_mask &= ~(1ull << i);
+				continue;
+			}
+			if (!reg->precise)
+				new_marks = true;
+			reg->precise = true;
+		}
+		if (env->log.level & BPF_LOG_LEVEL) {
+			print_verifier_state(env, func);
+			verbose(env, "parent %s regs=%x stack=%llx marks\n",
+				new_marks ? "didn't have" : "already had",
+				reg_mask, stack_mask);
+		}
+
+		if (!reg_mask && !stack_mask)
+			break;
+		if (!new_marks)
+			break;
+
+		last_idx = st->last_insn_idx;
+		first_idx = st->first_insn_idx;
+	}
+	return 0;
+}
+
+static int mark_chain_precision(struct bpf_verifier_env *env, int regno)
+{
+	return __mark_chain_precision(env, env->cur_state->curframe, regno, -1);
+}
+
+static int mark_chain_precision_frame(struct bpf_verifier_env *env, int frame, int regno)
+{
+	return __mark_chain_precision(env, frame, regno, -1);
+}
+
+static int mark_chain_precision_stack_frame(struct bpf_verifier_env *env, int frame, int spi)
+{
+	return __mark_chain_precision(env, frame, -1, spi);
+}
+
+static bool is_spillable_regtype(enum bpf_reg_type type)
+{
+	switch (type) {
+	case PTR_TO_MAP_VALUE:
+	case PTR_TO_MAP_VALUE_OR_NULL:
+	case PTR_TO_STACK:
+	case PTR_TO_CTX:
+	case PTR_TO_PACKET:
+	case PTR_TO_PACKET_META:
+	case PTR_TO_PACKET_END:
+	case PTR_TO_FLOW_KEYS:
+	case CONST_PTR_TO_MAP:
+	case PTR_TO_SOCKET:
+	case PTR_TO_SOCKET_OR_NULL:
+	case PTR_TO_SOCK_COMMON:
+	case PTR_TO_SOCK_COMMON_OR_NULL:
+	case PTR_TO_TCP_SOCK:
+	case PTR_TO_TCP_SOCK_OR_NULL:
+	case PTR_TO_XDP_SOCK:
+	case PTR_TO_BTF_ID:
+	case PTR_TO_BTF_ID_OR_NULL:
+	case PTR_TO_RDONLY_BUF:
+	case PTR_TO_RDONLY_BUF_OR_NULL:
+	case PTR_TO_RDWR_BUF:
+	case PTR_TO_RDWR_BUF_OR_NULL:
+	case PTR_TO_PERCPU_BTF_ID:
+	case PTR_TO_MEM:
+	case PTR_TO_MEM_OR_NULL:
+		return true;
+	default:
+		return false;
+	}
+}
+
+/* Does this register contain a constant zero? */
+static bool register_is_null(struct bpf_reg_state *reg)
+{
+	return reg->type == SCALAR_VALUE && tnum_equals_const(reg->var_off, 0);
+}
+
+static bool register_is_const(struct bpf_reg_state *reg)
+{
+	return reg->type == SCALAR_VALUE && tnum_is_const(reg->var_off);
+}
+
+static bool __is_scalar_unbounded(struct bpf_reg_state *reg)
+{
+	return tnum_is_unknown(reg->var_off) &&
+	       reg->smin_value == S64_MIN && reg->smax_value == S64_MAX &&
+	       reg->umin_value == 0 && reg->umax_value == U64_MAX &&
+	       reg->s32_min_value == S32_MIN && reg->s32_max_value == S32_MAX &&
+	       reg->u32_min_value == 0 && reg->u32_max_value == U32_MAX;
+}
+
+static bool register_is_bounded(struct bpf_reg_state *reg)
+{
+	return reg->type == SCALAR_VALUE && !__is_scalar_unbounded(reg);
+}
+
+static bool __is_pointer_value(bool allow_ptr_leaks,
+			       const struct bpf_reg_state *reg)
+{
+	if (allow_ptr_leaks)
+		return false;
+
+	return reg->type != SCALAR_VALUE;
+}
+
+/* Copy src state preserving dst->parent and dst->live fields */
+static void copy_register_state(struct bpf_reg_state *dst, const struct bpf_reg_state *src)
+{
+	struct bpf_reg_state *parent = dst->parent;
+	enum bpf_reg_liveness live = dst->live;
+
+	*dst = *src;
+	dst->parent = parent;
+	dst->live = live;
+}
+
+static void save_register_state(struct bpf_func_state *state,
+				int spi, struct bpf_reg_state *reg,
+				int size)
+{
+	int i;
+
+	copy_register_state(&state->stack[spi].spilled_ptr, reg);
+	if (size == BPF_REG_SIZE)
+		state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
+
+	for (i = BPF_REG_SIZE; i > BPF_REG_SIZE - size; i--)
+		state->stack[spi].slot_type[i - 1] = STACK_SPILL;
+
+	/* size < 8 bytes spill */
+	for (; i; i--)
+		scrub_spilled_slot(&state->stack[spi].slot_type[i - 1]);
+}
+
+static bool is_bpf_st_mem(struct bpf_insn *insn)
+{
+	return BPF_CLASS(insn->code) == BPF_ST && BPF_MODE(insn->code) == BPF_MEM;
+}
+
+/* check_stack_{read,write}_fixed_off functions track spill/fill of registers,
+ * stack boundary and alignment are checked in check_mem_access()
+ */
+static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
+				       /* stack frame we're writing to */
+				       struct bpf_func_state *state,
+				       int off, int size, int value_regno,
+				       int insn_idx)
+{
+	struct bpf_func_state *cur; /* state of the current function */
+	int i, slot = -off - 1, spi = slot / BPF_REG_SIZE, err;
+	struct bpf_insn *insn = &env->prog->insnsi[insn_idx];
+	struct bpf_reg_state *reg = NULL;
+	u32 dst_reg = insn->dst_reg;
+
+	err = realloc_func_state(state, round_up(slot + 1, BPF_REG_SIZE),
+				 state->acquired_refs, true);
+	if (err)
+		return err;
+	/* caller checked that off % size == 0 and -MAX_BPF_STACK <= off < 0,
+	 * so it's aligned access and [off, off + size) are within stack limits
+	 */
+	if (!env->allow_ptr_leaks &&
+	    is_spilled_reg(&state->stack[spi]) &&
+	    size != BPF_REG_SIZE) {
+		verbose(env, "attempt to corrupt spilled pointer on stack\n");
+		return -EACCES;
+	}
+
+	cur = env->cur_state->frame[env->cur_state->curframe];
+	if (value_regno >= 0)
+		reg = &cur->regs[value_regno];
+	if (!env->bypass_spec_v4) {
+		bool sanitize = reg && is_spillable_regtype(reg->type);
+
+		for (i = 0; i < size; i++) {
+			u8 type = state->stack[spi].slot_type[i];
+
+			if (type != STACK_MISC && type != STACK_ZERO) {
+				sanitize = true;
+				break;
+			}
+		}
+
+		if (sanitize)
+			env->insn_aux_data[insn_idx].sanitize_stack_spill = true;
+	}
+
+	if (reg && !(off % BPF_REG_SIZE) && register_is_bounded(reg) &&
+	    !register_is_null(reg) && env->bpf_capable) {
+		if (dst_reg != BPF_REG_FP) {
+			/* The backtracking logic can only recognize explicit
+			 * stack slot address like [fp - 8]. Other spill of
+			 * scalar via different register has to be conervative.
+			 * Backtrack from here and mark all registers as precise
+			 * that contributed into 'reg' being a constant.
+			 */
+			err = mark_chain_precision(env, value_regno);
+			if (err)
+				return err;
+		}
+		save_register_state(state, spi, reg, size);
+		/* Break the relation on a narrowing spill. */
+		if (fls64(reg->umax_value) > BITS_PER_BYTE * size)
+			state->stack[spi].spilled_ptr.id = 0;
+	} else if (!reg && !(off % BPF_REG_SIZE) && is_bpf_st_mem(insn) &&
+		   insn->imm != 0 && env->bpf_capable) {
+		struct bpf_reg_state fake_reg = {};
+
+		__mark_reg_known(&fake_reg, insn->imm);
+		fake_reg.type = SCALAR_VALUE;
+		save_register_state(state, spi, &fake_reg, size);
+	} else if (reg && is_spillable_regtype(reg->type)) {
+		/* register containing pointer is being spilled into stack */
+		if (size != BPF_REG_SIZE) {
+			verbose_linfo(env, insn_idx, "; ");
+			verbose(env, "invalid size of register spill\n");
+			return -EACCES;
+		}
+		if (state != cur && reg->type == PTR_TO_STACK) {
+			verbose(env, "cannot spill pointers to stack into stack frame of the caller\n");
+			return -EINVAL;
+		}
+		save_register_state(state, spi, reg, size);
+	} else {
+		u8 type = STACK_MISC;
+
+		/* regular write of data into stack destroys any spilled ptr */
+		state->stack[spi].spilled_ptr.type = NOT_INIT;
+		/* Mark slots as STACK_MISC if they belonged to spilled ptr. */
+		if (is_spilled_reg(&state->stack[spi]))
+			for (i = 0; i < BPF_REG_SIZE; i++)
+				scrub_spilled_slot(&state->stack[spi].slot_type[i]);
+
+		/* only mark the slot as written if all 8 bytes were written
+		 * otherwise read propagation may incorrectly stop too soon
+		 * when stack slots are partially written.
+		 * This heuristic means that read propagation will be
+		 * conservative, since it will add reg_live_read marks
+		 * to stack slots all the way to first state when programs
+		 * writes+reads less than 8 bytes
+		 */
+		if (size == BPF_REG_SIZE)
+			state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
+
+		/* when we zero initialize stack slots mark them as such */
+		if ((reg && register_is_null(reg)) ||
+		    (!reg && is_bpf_st_mem(insn) && insn->imm == 0)) {
+			/* backtracking doesn't work for STACK_ZERO yet. */
+			err = mark_chain_precision(env, value_regno);
+			if (err)
+				return err;
+			type = STACK_ZERO;
+		}
+
+		/* Mark slots affected by this stack write. */
+		for (i = 0; i < size; i++)
+			state->stack[spi].slot_type[(slot - i) % BPF_REG_SIZE] =
+				type;
+	}
+	return 0;
+}
+
+/* Write the stack: 'stack[ptr_regno + off] = value_regno'. 'ptr_regno' is
+ * known to contain a variable offset.
+ * This function checks whether the write is permitted and conservatively
+ * tracks the effects of the write, considering that each stack slot in the
+ * dynamic range is potentially written to.
+ *
+ * 'off' includes 'regno->off'.
+ * 'value_regno' can be -1, meaning that an unknown value is being written to
+ * the stack.
+ *
+ * Spilled pointers in range are not marked as written because we don't know
+ * what's going to be actually written. This means that read propagation for
+ * future reads cannot be terminated by this write.
+ *
+ * For privileged programs, uninitialized stack slots are considered
+ * initialized by this write (even though we don't know exactly what offsets
+ * are going to be written to). The idea is that we don't want the verifier to
+ * reject future reads that access slots written to through variable offsets.
+ */
+static int check_stack_write_var_off(struct bpf_verifier_env *env,
+				     /* func where register points to */
+				     struct bpf_func_state *state,
+				     int ptr_regno, int off, int size,
+				     int value_regno, int insn_idx)
+{
+	struct bpf_func_state *cur; /* state of the current function */
+	int min_off, max_off;
+	int i, err;
+	struct bpf_reg_state *ptr_reg = NULL, *value_reg = NULL;
+	bool writing_zero = false;
+	/* set if the fact that we're writing a zero is used to let any
+	 * stack slots remain STACK_ZERO
+	 */
+	bool zero_used = false;
+
+	cur = env->cur_state->frame[env->cur_state->curframe];
+	ptr_reg = &cur->regs[ptr_regno];
+	min_off = ptr_reg->smin_value + off;
+	max_off = ptr_reg->smax_value + off + size;
+	if (value_regno >= 0)
+		value_reg = &cur->regs[value_regno];
+	if (value_reg && register_is_null(value_reg))
+		writing_zero = true;
+
+	err = realloc_func_state(state, round_up(-min_off, BPF_REG_SIZE),
+				 state->acquired_refs, true);
+	if (err)
+		return err;
+
+
+	/* Variable offset writes destroy any spilled pointers in range. */
+	for (i = min_off; i < max_off; i++) {
+		u8 new_type, *stype;
+		int slot, spi;
+
+		slot = -i - 1;
+		spi = slot / BPF_REG_SIZE;
+		stype = &state->stack[spi].slot_type[slot % BPF_REG_SIZE];
+
+		if (!env->allow_ptr_leaks && *stype != STACK_MISC && *stype != STACK_ZERO) {
+			/* Reject the write if range we may write to has not
+			 * been initialized beforehand. If we didn't reject
+			 * here, the ptr status would be erased below (even
+			 * though not all slots are actually overwritten),
+			 * possibly opening the door to leaks.
+			 *
+			 * We do however catch STACK_INVALID case below, and
+			 * only allow reading possibly uninitialized memory
+			 * later for CAP_PERFMON, as the write may not happen to
+			 * that slot.
+			 */
+			verbose(env, "spilled ptr in range of var-offset stack write; insn %d, ptr off: %d",
+				insn_idx, i);
+			return -EINVAL;
+		}
+
+		/* Erase all spilled pointers. */
+		state->stack[spi].spilled_ptr.type = NOT_INIT;
+
+		/* Update the slot type. */
+		new_type = STACK_MISC;
+		if (writing_zero && *stype == STACK_ZERO) {
+			new_type = STACK_ZERO;
+			zero_used = true;
+		}
+		/* If the slot is STACK_INVALID, we check whether it's OK to
+		 * pretend that it will be initialized by this write. The slot
+		 * might not actually be written to, and so if we mark it as
+		 * initialized future reads might leak uninitialized memory.
+		 * For privileged programs, we will accept such reads to slots
+		 * that may or may not be written because, if we're reject
+		 * them, the error would be too confusing.
+		 */
+		if (*stype == STACK_INVALID && !env->allow_uninit_stack) {
+			verbose(env, "uninit stack in range of var-offset write prohibited for !root; insn %d, off: %d",
+					insn_idx, i);
+			return -EINVAL;
+		}
+		*stype = new_type;
+	}
+	if (zero_used) {
+		/* backtracking doesn't work for STACK_ZERO yet. */
+		err = mark_chain_precision(env, value_regno);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
+/* When register 'dst_regno' is assigned some values from stack[min_off,
+ * max_off), we set the register's type according to the types of the
+ * respective stack slots. If all the stack values are known to be zeros, then
+ * so is the destination reg. Otherwise, the register is considered to be
+ * SCALAR. This function does not deal with register filling; the caller must
+ * ensure that all spilled registers in the stack range have been marked as
+ * read.
+ */
+static void mark_reg_stack_read(struct bpf_verifier_env *env,
+				/* func where src register points to */
+				struct bpf_func_state *ptr_state,
+				int min_off, int max_off, int dst_regno)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	int i, slot, spi;
+	u8 *stype;
+	int zeros = 0;
+
+	for (i = min_off; i < max_off; i++) {
+		slot = -i - 1;
+		spi = slot / BPF_REG_SIZE;
+		stype = ptr_state->stack[spi].slot_type;
+		if (stype[slot % BPF_REG_SIZE] != STACK_ZERO)
+			break;
+		zeros++;
+	}
+	if (zeros == max_off - min_off) {
+		/* any access_size read into register is zero extended,
+		 * so the whole register == const_zero
+		 */
+		__mark_reg_const_zero(&state->regs[dst_regno]);
+		/* backtracking doesn't support STACK_ZERO yet,
+		 * so mark it precise here, so that later
+		 * backtracking can stop here.
+		 * Backtracking may not need this if this register
+		 * doesn't participate in pointer adjustment.
+		 * Forward propagation of precise flag is not
+		 * necessary either. This mark is only to stop
+		 * backtracking. Any register that contributed
+		 * to const 0 was marked precise before spill.
+		 */
+		state->regs[dst_regno].precise = true;
+	} else {
+		/* have read misc data from the stack */
+		mark_reg_unknown(env, state->regs, dst_regno);
+	}
+	state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
+}
+
+/* Read the stack at 'off' and put the results into the register indicated by
+ * 'dst_regno'. It handles reg filling if the addressed stack slot is a
+ * spilled reg.
+ *
+ * 'dst_regno' can be -1, meaning that the read value is not going to a
+ * register.
+ *
+ * The access is assumed to be within the current stack bounds.
+ */
+static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
+				      /* func where src register points to */
+				      struct bpf_func_state *reg_state,
+				      int off, int size, int dst_regno)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	int i, slot = -off - 1, spi = slot / BPF_REG_SIZE;
+	struct bpf_reg_state *reg;
+	u8 *stype, type;
+
+	stype = reg_state->stack[spi].slot_type;
+	reg = &reg_state->stack[spi].spilled_ptr;
+
+	if (is_spilled_reg(&reg_state->stack[spi])) {
+		u8 spill_size = 1;
+
+		for (i = BPF_REG_SIZE - 1; i > 0 && stype[i - 1] == STACK_SPILL; i--)
+			spill_size++;
+
+		if (size != BPF_REG_SIZE || spill_size != BPF_REG_SIZE) {
+			if (reg->type != SCALAR_VALUE) {
+				verbose_linfo(env, env->insn_idx, "; ");
+				verbose(env, "invalid size of register fill\n");
+				return -EACCES;
+			}
+
+			mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
+			if (dst_regno < 0)
+				return 0;
+
+			if (!(off % BPF_REG_SIZE) && size == spill_size) {
+				/* The earlier check_reg_arg() has decided the
+				 * subreg_def for this insn.  Save it first.
+				 */
+				s32 subreg_def = state->regs[dst_regno].subreg_def;
+
+				copy_register_state(&state->regs[dst_regno], reg);
+				state->regs[dst_regno].subreg_def = subreg_def;
+			} else {
+				for (i = 0; i < size; i++) {
+					type = stype[(slot - i) % BPF_REG_SIZE];
+					if (type == STACK_SPILL)
+						continue;
+					if (type == STACK_MISC)
+						continue;
+					verbose(env, "invalid read from stack off %d+%d size %d\n",
+						off, i, size);
+					return -EACCES;
+				}
+				mark_reg_unknown(env, state->regs, dst_regno);
+			}
+			state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
+			return 0;
+		}
+
+		if (dst_regno >= 0) {
+			/* restore register state from stack */
+			copy_register_state(&state->regs[dst_regno], reg);
+			/* mark reg as written since spilled pointer state likely
+			 * has its liveness marks cleared by is_state_visited()
+			 * which resets stack/reg liveness for state transitions
+			 */
+			state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
+		} else if (__is_pointer_value(env->allow_ptr_leaks, reg)) {
+			/* If dst_regno==-1, the caller is asking us whether
+			 * it is acceptable to use this value as a SCALAR_VALUE
+			 * (e.g. for XADD).
+			 * We must not allow unprivileged callers to do that
+			 * with spilled pointers.
+			 */
+			verbose(env, "leaking pointer from stack off %d\n",
+				off);
+			return -EACCES;
+		}
+		mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
+	} else {
+		for (i = 0; i < size; i++) {
+			type = stype[(slot - i) % BPF_REG_SIZE];
+			if (type == STACK_MISC)
+				continue;
+			if (type == STACK_ZERO)
+				continue;
+			verbose(env, "invalid read from stack off %d+%d size %d\n",
+				off, i, size);
+			return -EACCES;
+		}
+		mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
+		if (dst_regno >= 0)
+			mark_reg_stack_read(env, reg_state, off, off + size, dst_regno);
+	}
+	return 0;
+}
+
+enum stack_access_src {
+	ACCESS_DIRECT = 1,  /* the access is performed by an instruction */
+	ACCESS_HELPER = 2,  /* the access is performed by a helper */
+};
+
+static int check_stack_range_initialized(struct bpf_verifier_env *env,
+					 int regno, int off, int access_size,
+					 bool zero_size_allowed,
+					 enum stack_access_src type,
+					 struct bpf_call_arg_meta *meta);
+
+static struct bpf_reg_state *reg_state(struct bpf_verifier_env *env, int regno)
+{
+	return cur_regs(env) + regno;
+}
+
+/* Read the stack at 'ptr_regno + off' and put the result into the register
+ * 'dst_regno'.
+ * 'off' includes the pointer register's fixed offset(i.e. 'ptr_regno.off'),
+ * but not its variable offset.
+ * 'size' is assumed to be <= reg size and the access is assumed to be aligned.
+ *
+ * As opposed to check_stack_read_fixed_off, this function doesn't deal with
+ * filling registers (i.e. reads of spilled register cannot be detected when
+ * the offset is not fixed). We conservatively mark 'dst_regno' as containing
+ * SCALAR_VALUE. That's why we assert that the 'ptr_regno' has a variable
+ * offset; for a fixed offset check_stack_read_fixed_off should be used
+ * instead.
+ */
+static int check_stack_read_var_off(struct bpf_verifier_env *env,
+				    int ptr_regno, int off, int size, int dst_regno)
+{
+	/* The state of the source register. */
+	struct bpf_reg_state *reg = reg_state(env, ptr_regno);
+	struct bpf_func_state *ptr_state = func(env, reg);
+	int err;
+	int min_off, max_off;
+
+	/* Note that we pass a NULL meta, so raw access will not be permitted.
+	 */
+	err = check_stack_range_initialized(env, ptr_regno, off, size,
+					    false, ACCESS_DIRECT, NULL);
+	if (err)
+		return err;
+
+	min_off = reg->smin_value + off;
+	max_off = reg->smax_value + off;
+	mark_reg_stack_read(env, ptr_state, min_off, max_off + size, dst_regno);
+	return 0;
+}
+
+/* check_stack_read dispatches to check_stack_read_fixed_off or
+ * check_stack_read_var_off.
+ *
+ * The caller must ensure that the offset falls within the allocated stack
+ * bounds.
+ *
+ * 'dst_regno' is a register which will receive the value from the stack. It
+ * can be -1, meaning that the read value is not going to a register.
+ */
+static int check_stack_read(struct bpf_verifier_env *env,
+			    int ptr_regno, int off, int size,
+			    int dst_regno)
+{
+	struct bpf_reg_state *reg = reg_state(env, ptr_regno);
+	struct bpf_func_state *state = func(env, reg);
+	int err;
+	/* Some accesses are only permitted with a static offset. */
+	bool var_off = !tnum_is_const(reg->var_off);
+
+	/* The offset is required to be static when reads don't go to a
+	 * register, in order to not leak pointers (see
+	 * check_stack_read_fixed_off).
+	 */
+	if (dst_regno < 0 && var_off) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env, "variable offset stack pointer cannot be passed into helper function; var_off=%s off=%d size=%d\n",
+			tn_buf, off, size);
+		return -EACCES;
+	}
+	/* Variable offset is prohibited for unprivileged mode for simplicity
+	 * since it requires corresponding support in Spectre masking for stack
+	 * ALU. See also retrieve_ptr_limit(). The check in
+	 * check_stack_access_for_ptr_arithmetic() called by
+	 * adjust_ptr_min_max_vals() prevents users from creating stack pointers
+	 * with variable offsets, therefore no check is required here. Further,
+	 * just checking it here would be insufficient as speculative stack
+	 * writes could still lead to unsafe speculative behaviour.
+	 */
+	if (!var_off) {
+		off += reg->var_off.value;
+		err = check_stack_read_fixed_off(env, state, off, size,
+						 dst_regno);
+	} else {
+		/* Variable offset stack reads need more conservative handling
+		 * than fixed offset ones. Note that dst_regno >= 0 on this
+		 * branch.
+		 */
+		err = check_stack_read_var_off(env, ptr_regno, off, size,
+					       dst_regno);
+	}
+	return err;
+}
+
+
+/* check_stack_write dispatches to check_stack_write_fixed_off or
+ * check_stack_write_var_off.
+ *
+ * 'ptr_regno' is the register used as a pointer into the stack.
+ * 'off' includes 'ptr_regno->off', but not its variable offset (if any).
+ * 'value_regno' is the register whose value we're writing to the stack. It can
+ * be -1, meaning that we're not writing from a register.
+ *
+ * The caller must ensure that the offset falls within the maximum stack size.
+ */
+static int check_stack_write(struct bpf_verifier_env *env,
+			     int ptr_regno, int off, int size,
+			     int value_regno, int insn_idx)
+{
+	struct bpf_reg_state *reg = reg_state(env, ptr_regno);
+	struct bpf_func_state *state = func(env, reg);
+	int err;
+
+	if (tnum_is_const(reg->var_off)) {
+		off += reg->var_off.value;
+		err = check_stack_write_fixed_off(env, state, off, size,
+						  value_regno, insn_idx);
+	} else {
+		/* Variable offset stack reads need more conservative handling
+		 * than fixed offset ones.
+		 */
+		err = check_stack_write_var_off(env, state,
+						ptr_regno, off, size,
+						value_regno, insn_idx);
+	}
+	return err;
+}
+
+static int check_map_access_type(struct bpf_verifier_env *env, u32 regno,
+				 int off, int size, enum bpf_access_type type)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_map *map = regs[regno].map_ptr;
+	u32 cap = bpf_map_flags_to_cap(map);
+
+	if (type == BPF_WRITE && !(cap & BPF_MAP_CAN_WRITE)) {
+		verbose(env, "write into map forbidden, value_size=%d off=%d size=%d\n",
+			map->value_size, off, size);
+		return -EACCES;
+	}
+
+	if (type == BPF_READ && !(cap & BPF_MAP_CAN_READ)) {
+		verbose(env, "read from map forbidden, value_size=%d off=%d size=%d\n",
+			map->value_size, off, size);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
+/* check read/write into memory region (e.g., map value, ringbuf sample, etc) */
+static int __check_mem_access(struct bpf_verifier_env *env, int regno,
+			      int off, int size, u32 mem_size,
+			      bool zero_size_allowed)
+{
+	bool size_ok = size > 0 || (size == 0 && zero_size_allowed);
+	struct bpf_reg_state *reg;
+
+	if (off >= 0 && size_ok && (u64)off + size <= mem_size)
+		return 0;
+
+	reg = &cur_regs(env)[regno];
+	switch (reg->type) {
+	case PTR_TO_MAP_VALUE:
+		verbose(env, "invalid access to map value, value_size=%d off=%d size=%d\n",
+			mem_size, off, size);
+		break;
+	case PTR_TO_PACKET:
+	case PTR_TO_PACKET_META:
+	case PTR_TO_PACKET_END:
+		verbose(env, "invalid access to packet, off=%d size=%d, R%d(id=%d,off=%d,r=%d)\n",
+			off, size, regno, reg->id, off, mem_size);
+		break;
+	case PTR_TO_MEM:
+	default:
+		verbose(env, "invalid access to memory, mem_size=%u off=%d size=%d\n",
+			mem_size, off, size);
+	}
+
+	return -EACCES;
+}
+
+/* check read/write into a memory region with possible variable offset */
+static int check_mem_region_access(struct bpf_verifier_env *env, u32 regno,
+				   int off, int size, u32 mem_size,
+				   bool zero_size_allowed)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	struct bpf_reg_state *reg = &state->regs[regno];
+	int err;
+
+	/* We may have adjusted the register pointing to memory region, so we
+	 * need to try adding each of min_value and max_value to off
+	 * to make sure our theoretical access will be safe.
+	 */
+	if (env->log.level & BPF_LOG_LEVEL)
+		print_verifier_state(env, state);
+
+	/* The minimum value is only important with signed
+	 * comparisons where we can't assume the floor of a
+	 * value is 0.  If we are using signed variables for our
+	 * index'es we need to make sure that whatever we use
+	 * will have a set floor within our range.
+	 */
+	if (reg->smin_value < 0 &&
+	    (reg->smin_value == S64_MIN ||
+	     (off + reg->smin_value != (s64)(s32)(off + reg->smin_value)) ||
+	      reg->smin_value + off < 0)) {
+		verbose(env, "R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n",
+			regno);
+		return -EACCES;
+	}
+	err = __check_mem_access(env, regno, reg->smin_value + off, size,
+				 mem_size, zero_size_allowed);
+	if (err) {
+		verbose(env, "R%d min value is outside of the allowed memory range\n",
+			regno);
+		return err;
+	}
+
+	/* If we haven't set a max value then we need to bail since we can't be
+	 * sure we won't do bad things.
+	 * If reg->umax_value + off could overflow, treat that as unbounded too.
+	 */
+	if (reg->umax_value >= BPF_MAX_VAR_OFF) {
+		verbose(env, "R%d unbounded memory access, make sure to bounds check any such access\n",
+			regno);
+		return -EACCES;
+	}
+	err = __check_mem_access(env, regno, reg->umax_value + off, size,
+				 mem_size, zero_size_allowed);
+	if (err) {
+		verbose(env, "R%d max value is outside of the allowed memory range\n",
+			regno);
+		return err;
+	}
+
+	return 0;
+}
+
+/* check read/write into a map element with possible variable offset */
+static int check_map_access(struct bpf_verifier_env *env, u32 regno,
+			    int off, int size, bool zero_size_allowed)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	struct bpf_reg_state *reg = &state->regs[regno];
+	struct bpf_map *map = reg->map_ptr;
+	int err;
+
+	err = check_mem_region_access(env, regno, off, size, map->value_size,
+				      zero_size_allowed);
+	if (err)
+		return err;
+
+	if (map_value_has_spin_lock(map)) {
+		u32 lock = map->spin_lock_off;
+
+		/* if any part of struct bpf_spin_lock can be touched by
+		 * load/store reject this program.
+		 * To check that [x1, x2) overlaps with [y1, y2)
+		 * it is sufficient to check x1 < y2 && y1 < x2.
+		 */
+		if (reg->smin_value + off < lock + sizeof(struct bpf_spin_lock) &&
+		     lock < reg->umax_value + off + size) {
+			verbose(env, "bpf_spin_lock cannot be accessed directly by load/store\n");
+			return -EACCES;
+		}
+	}
+	return err;
+}
+
+#define MAX_PACKET_OFF 0xffff
+
+static enum bpf_prog_type resolve_prog_type(struct bpf_prog *prog)
+{
+	return prog->aux->dst_prog ? prog->aux->dst_prog->type : prog->type;
+}
+
+static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
+				       const struct bpf_call_arg_meta *meta,
+				       enum bpf_access_type t)
+{
+	enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
+
+	switch (prog_type) {
+	/* Program types only with direct read access go here! */
+	case BPF_PROG_TYPE_LWT_IN:
+	case BPF_PROG_TYPE_LWT_OUT:
+	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
+	case BPF_PROG_TYPE_SK_REUSEPORT:
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+	case BPF_PROG_TYPE_CGROUP_SKB:
+		if (t == BPF_WRITE)
+			return false;
+		fallthrough;
+
+	/* Program types with direct read + write access go here! */
+	case BPF_PROG_TYPE_SCHED_CLS:
+	case BPF_PROG_TYPE_SCHED_ACT:
+	case BPF_PROG_TYPE_XDP:
+	case BPF_PROG_TYPE_LWT_XMIT:
+	case BPF_PROG_TYPE_SK_SKB:
+	case BPF_PROG_TYPE_SK_MSG:
+		if (meta)
+			return meta->pkt_access;
+
+		env->seen_direct_write = true;
+		return true;
+
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+		if (t == BPF_WRITE)
+			env->seen_direct_write = true;
+
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off,
+			       int size, bool zero_size_allowed)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_reg_state *reg = &regs[regno];
+	int err;
+
+	/* We may have added a variable offset to the packet pointer; but any
+	 * reg->range we have comes after that.  We are only checking the fixed
+	 * offset.
+	 */
+
+	/* We don't allow negative numbers, because we aren't tracking enough
+	 * detail to prove they're safe.
+	 */
+	if (reg->smin_value < 0) {
+		verbose(env, "R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n",
+			regno);
+		return -EACCES;
+	}
+
+	err = reg->range < 0 ? -EINVAL :
+	      __check_mem_access(env, regno, off, size, reg->range,
+				 zero_size_allowed);
+	if (err) {
+		verbose(env, "R%d offset is outside of the packet\n", regno);
+		return err;
+	}
+
+	/* __check_mem_access has made sure "off + size - 1" is within u16.
+	 * reg->umax_value can't be bigger than MAX_PACKET_OFF which is 0xffff,
+	 * otherwise find_good_pkt_pointers would have refused to set range info
+	 * that __check_mem_access would have rejected this pkt access.
+	 * Therefore, "off + reg->umax_value + size - 1" won't overflow u32.
+	 */
+	env->prog->aux->max_pkt_offset =
+		max_t(u32, env->prog->aux->max_pkt_offset,
+		      off + reg->umax_value + size - 1);
+
+	return err;
+}
+
+/* check access to 'struct bpf_context' fields.  Supports fixed offsets only */
+static int check_ctx_access(struct bpf_verifier_env *env, int insn_idx, int off, int size,
+			    enum bpf_access_type t, enum bpf_reg_type *reg_type,
+			    u32 *btf_id)
+{
+	struct bpf_insn_access_aux info = {
+		.reg_type = *reg_type,
+		.log = &env->log,
+	};
+
+	if (env->ops->is_valid_access &&
+	    env->ops->is_valid_access(off, size, t, env->prog, &info)) {
+		/* A non zero info.ctx_field_size indicates that this field is a
+		 * candidate for later verifier transformation to load the whole
+		 * field and then apply a mask when accessed with a narrower
+		 * access than actual ctx access size. A zero info.ctx_field_size
+		 * will only allow for whole field access and rejects any other
+		 * type of narrower access.
+		 */
+		*reg_type = info.reg_type;
+
+		if (*reg_type == PTR_TO_BTF_ID || *reg_type == PTR_TO_BTF_ID_OR_NULL)
+			*btf_id = info.btf_id;
+		else
+			env->insn_aux_data[insn_idx].ctx_field_size = info.ctx_field_size;
+		/* remember the offset of last byte accessed in ctx */
+		if (env->prog->aux->max_ctx_offset < off + size)
+			env->prog->aux->max_ctx_offset = off + size;
+		return 0;
+	}
+
+	verbose(env, "invalid bpf_context access off=%d size=%d\n", off, size);
+	return -EACCES;
+}
+
+static int check_flow_keys_access(struct bpf_verifier_env *env, int off,
+				  int size)
+{
+	if (size < 0 || off < 0 ||
+	    (u64)off + size > sizeof(struct bpf_flow_keys)) {
+		verbose(env, "invalid access to flow keys off=%d size=%d\n",
+			off, size);
+		return -EACCES;
+	}
+	return 0;
+}
+
+static int check_sock_access(struct bpf_verifier_env *env, int insn_idx,
+			     u32 regno, int off, int size,
+			     enum bpf_access_type t)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_reg_state *reg = &regs[regno];
+	struct bpf_insn_access_aux info = {};
+	bool valid;
+
+	if (reg->smin_value < 0) {
+		verbose(env, "R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n",
+			regno);
+		return -EACCES;
+	}
+
+	switch (reg->type) {
+	case PTR_TO_SOCK_COMMON:
+		valid = bpf_sock_common_is_valid_access(off, size, t, &info);
+		break;
+	case PTR_TO_SOCKET:
+		valid = bpf_sock_is_valid_access(off, size, t, &info);
+		break;
+	case PTR_TO_TCP_SOCK:
+		valid = bpf_tcp_sock_is_valid_access(off, size, t, &info);
+		break;
+	case PTR_TO_XDP_SOCK:
+		valid = bpf_xdp_sock_is_valid_access(off, size, t, &info);
+		break;
+	default:
+		valid = false;
+	}
+
+
+	if (valid) {
+		env->insn_aux_data[insn_idx].ctx_field_size =
+			info.ctx_field_size;
+		return 0;
+	}
+
+	verbose(env, "R%d invalid %s access off=%d size=%d\n",
+		regno, reg_type_str[reg->type], off, size);
+
+	return -EACCES;
+}
+
+static bool is_pointer_value(struct bpf_verifier_env *env, int regno)
+{
+	return __is_pointer_value(env->allow_ptr_leaks, reg_state(env, regno));
+}
+
+static bool is_ctx_reg(struct bpf_verifier_env *env, int regno)
+{
+	const struct bpf_reg_state *reg = reg_state(env, regno);
+
+	return reg->type == PTR_TO_CTX;
+}
+
+static bool is_sk_reg(struct bpf_verifier_env *env, int regno)
+{
+	const struct bpf_reg_state *reg = reg_state(env, regno);
+
+	return type_is_sk_pointer(reg->type);
+}
+
+static bool is_pkt_reg(struct bpf_verifier_env *env, int regno)
+{
+	const struct bpf_reg_state *reg = reg_state(env, regno);
+
+	return type_is_pkt_pointer(reg->type);
+}
+
+static bool is_flow_key_reg(struct bpf_verifier_env *env, int regno)
+{
+	const struct bpf_reg_state *reg = reg_state(env, regno);
+
+	/* Separate to is_ctx_reg() since we still want to allow BPF_ST here. */
+	return reg->type == PTR_TO_FLOW_KEYS;
+}
+
+static int check_pkt_ptr_alignment(struct bpf_verifier_env *env,
+				   const struct bpf_reg_state *reg,
+				   int off, int size, bool strict)
+{
+	struct tnum reg_off;
+	int ip_align;
+
+	/* Byte size accesses are always allowed. */
+	if (!strict || size == 1)
+		return 0;
+
+	/* For platforms that do not have a Kconfig enabling
+	 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS the value of
+	 * NET_IP_ALIGN is universally set to '2'.  And on platforms
+	 * that do set CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, we get
+	 * to this code only in strict mode where we want to emulate
+	 * the NET_IP_ALIGN==2 checking.  Therefore use an
+	 * unconditional IP align value of '2'.
+	 */
+	ip_align = 2;
+
+	reg_off = tnum_add(reg->var_off, tnum_const(ip_align + reg->off + off));
+	if (!tnum_is_aligned(reg_off, size)) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env,
+			"misaligned packet access off %d+%s+%d+%d size %d\n",
+			ip_align, tn_buf, reg->off, off, size);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
+static int check_generic_ptr_alignment(struct bpf_verifier_env *env,
+				       const struct bpf_reg_state *reg,
+				       const char *pointer_desc,
+				       int off, int size, bool strict)
+{
+	struct tnum reg_off;
+
+	/* Byte size accesses are always allowed. */
+	if (!strict || size == 1)
+		return 0;
+
+	reg_off = tnum_add(reg->var_off, tnum_const(reg->off + off));
+	if (!tnum_is_aligned(reg_off, size)) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env, "misaligned %saccess off %s+%d+%d size %d\n",
+			pointer_desc, tn_buf, reg->off, off, size);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
+static int check_ptr_alignment(struct bpf_verifier_env *env,
+			       const struct bpf_reg_state *reg, int off,
+			       int size, bool strict_alignment_once)
+{
+	bool strict = env->strict_alignment || strict_alignment_once;
+	const char *pointer_desc = "";
+
+	switch (reg->type) {
+	case PTR_TO_PACKET:
+	case PTR_TO_PACKET_META:
+		/* Special case, because of NET_IP_ALIGN. Given metadata sits
+		 * right in front, treat it the very same way.
+		 */
+		return check_pkt_ptr_alignment(env, reg, off, size, strict);
+	case PTR_TO_FLOW_KEYS:
+		pointer_desc = "flow keys ";
+		break;
+	case PTR_TO_MAP_VALUE:
+		pointer_desc = "value ";
+		break;
+	case PTR_TO_CTX:
+		pointer_desc = "context ";
+		break;
+	case PTR_TO_STACK:
+		pointer_desc = "stack ";
+		/* The stack spill tracking logic in check_stack_write_fixed_off()
+		 * and check_stack_read_fixed_off() relies on stack accesses being
+		 * aligned.
+		 */
+		strict = true;
+		break;
+	case PTR_TO_SOCKET:
+		pointer_desc = "sock ";
+		break;
+	case PTR_TO_SOCK_COMMON:
+		pointer_desc = "sock_common ";
+		break;
+	case PTR_TO_TCP_SOCK:
+		pointer_desc = "tcp_sock ";
+		break;
+	case PTR_TO_XDP_SOCK:
+		pointer_desc = "xdp_sock ";
+		break;
+	default:
+		break;
+	}
+	return check_generic_ptr_alignment(env, reg, pointer_desc, off, size,
+					   strict);
+}
+
+static int update_stack_depth(struct bpf_verifier_env *env,
+			      const struct bpf_func_state *func,
+			      int off)
+{
+	u16 stack = env->subprog_info[func->subprogno].stack_depth;
+
+	if (stack >= -off)
+		return 0;
+
+	/* update known max for given subprogram */
+	env->subprog_info[func->subprogno].stack_depth = -off;
+	return 0;
+}
+
+/* starting from main bpf function walk all instructions of the function
+ * and recursively walk all callees that given function can call.
+ * Ignore jump and exit insns.
+ * Since recursion is prevented by check_cfg() this algorithm
+ * only needs a local stack of MAX_CALL_FRAMES to remember callsites
+ */
+static int check_max_stack_depth(struct bpf_verifier_env *env)
+{
+	int depth = 0, frame = 0, idx = 0, i = 0, subprog_end;
+	struct bpf_subprog_info *subprog = env->subprog_info;
+	struct bpf_insn *insn = env->prog->insnsi;
+	bool tail_call_reachable = false;
+	int ret_insn[MAX_CALL_FRAMES];
+	int ret_prog[MAX_CALL_FRAMES];
+	int j;
+
+process_func:
+	/* protect against potential stack overflow that might happen when
+	 * bpf2bpf calls get combined with tailcalls. Limit the caller's stack
+	 * depth for such case down to 256 so that the worst case scenario
+	 * would result in 8k stack size (32 which is tailcall limit * 256 =
+	 * 8k).
+	 *
+	 * To get the idea what might happen, see an example:
+	 * func1 -> sub rsp, 128
+	 *  subfunc1 -> sub rsp, 256
+	 *  tailcall1 -> add rsp, 256
+	 *   func2 -> sub rsp, 192 (total stack size = 128 + 192 = 320)
+	 *   subfunc2 -> sub rsp, 64
+	 *   subfunc22 -> sub rsp, 128
+	 *   tailcall2 -> add rsp, 128
+	 *    func3 -> sub rsp, 32 (total stack size 128 + 192 + 64 + 32 = 416)
+	 *
+	 * tailcall will unwind the current stack frame but it will not get rid
+	 * of caller's stack as shown on the example above.
+	 */
+	if (idx && subprog[idx].has_tail_call && depth >= 256) {
+		verbose(env,
+			"tail_calls are not allowed when call stack of previous frames is %d bytes. Too large\n",
+			depth);
+		return -EACCES;
+	}
+	/* round up to 32-bytes, since this is granularity
+	 * of interpreter stack size
+	 */
+	depth += round_up(max_t(u32, subprog[idx].stack_depth, 1), 32);
+	if (depth > MAX_BPF_STACK) {
+		verbose(env, "combined stack size of %d calls is %d. Too large\n",
+			frame + 1, depth);
+		return -EACCES;
+	}
+continue_func:
+	subprog_end = subprog[idx + 1].start;
+	for (; i < subprog_end; i++) {
+		if (insn[i].code != (BPF_JMP | BPF_CALL))
+			continue;
+		if (insn[i].src_reg != BPF_PSEUDO_CALL)
+			continue;
+		/* remember insn and function to return to */
+		ret_insn[frame] = i + 1;
+		ret_prog[frame] = idx;
+
+		/* find the callee */
+		i = i + insn[i].imm + 1;
+		idx = find_subprog(env, i);
+		if (idx < 0) {
+			WARN_ONCE(1, "verifier bug. No program starts at insn %d\n",
+				  i);
+			return -EFAULT;
+		}
+
+		if (subprog[idx].has_tail_call)
+			tail_call_reachable = true;
+
+		frame++;
+		if (frame >= MAX_CALL_FRAMES) {
+			verbose(env, "the call stack of %d frames is too deep !\n",
+				frame);
+			return -E2BIG;
+		}
+		goto process_func;
+	}
+	/* if tail call got detected across bpf2bpf calls then mark each of the
+	 * currently present subprog frames as tail call reachable subprogs;
+	 * this info will be utilized by JIT so that we will be preserving the
+	 * tail call counter throughout bpf2bpf calls combined with tailcalls
+	 */
+	if (tail_call_reachable)
+		for (j = 0; j < frame; j++)
+			subprog[ret_prog[j]].tail_call_reachable = true;
+	if (subprog[0].tail_call_reachable)
+		env->prog->aux->tail_call_reachable = true;
+
+	/* end of for() loop means the last insn of the 'subprog'
+	 * was reached. Doesn't matter whether it was JA or EXIT
+	 */
+	if (frame == 0)
+		return 0;
+	depth -= round_up(max_t(u32, subprog[idx].stack_depth, 1), 32);
+	frame--;
+	i = ret_insn[frame];
+	idx = ret_prog[frame];
+	goto continue_func;
+}
+
+#ifndef CONFIG_BPF_JIT_ALWAYS_ON
+static int get_callee_stack_depth(struct bpf_verifier_env *env,
+				  const struct bpf_insn *insn, int idx)
+{
+	int start = idx + insn->imm + 1, subprog;
+
+	subprog = find_subprog(env, start);
+	if (subprog < 0) {
+		WARN_ONCE(1, "verifier bug. No program starts at insn %d\n",
+			  start);
+		return -EFAULT;
+	}
+	return env->subprog_info[subprog].stack_depth;
+}
+#endif
+
+int check_ctx_reg(struct bpf_verifier_env *env,
+		  const struct bpf_reg_state *reg, int regno)
+{
+	/* Access to ctx or passing it to a helper is only allowed in
+	 * its original, unmodified form.
+	 */
+
+	if (reg->off) {
+		verbose(env, "dereference of modified ctx ptr R%d off=%d disallowed\n",
+			regno, reg->off);
+		return -EACCES;
+	}
+
+	if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env, "variable ctx access var_off=%s disallowed\n", tn_buf);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
+static int __check_buffer_access(struct bpf_verifier_env *env,
+				 const char *buf_info,
+				 const struct bpf_reg_state *reg,
+				 int regno, int off, int size)
+{
+	if (off < 0) {
+		verbose(env,
+			"R%d invalid %s buffer access: off=%d, size=%d\n",
+			regno, buf_info, off, size);
+		return -EACCES;
+	}
+	if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env,
+			"R%d invalid variable buffer offset: off=%d, var_off=%s\n",
+			regno, off, tn_buf);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
+static int check_tp_buffer_access(struct bpf_verifier_env *env,
+				  const struct bpf_reg_state *reg,
+				  int regno, int off, int size)
+{
+	int err;
+
+	err = __check_buffer_access(env, "tracepoint", reg, regno, off, size);
+	if (err)
+		return err;
+
+	if (off + size > env->prog->aux->max_tp_access)
+		env->prog->aux->max_tp_access = off + size;
+
+	return 0;
+}
+
+static int check_buffer_access(struct bpf_verifier_env *env,
+			       const struct bpf_reg_state *reg,
+			       int regno, int off, int size,
+			       bool zero_size_allowed,
+			       const char *buf_info,
+			       u32 *max_access)
+{
+	int err;
+
+	err = __check_buffer_access(env, buf_info, reg, regno, off, size);
+	if (err)
+		return err;
+
+	if (off + size > *max_access)
+		*max_access = off + size;
+
+	return 0;
+}
+
+/* BPF architecture zero extends alu32 ops into 64-bit registesr */
+static void zext_32_to_64(struct bpf_reg_state *reg)
+{
+	reg->var_off = tnum_subreg(reg->var_off);
+	__reg_assign_32_into_64(reg);
+}
+
+/* truncate register to smaller size (in bytes)
+ * must be called with size < BPF_REG_SIZE
+ */
+static void coerce_reg_to_size(struct bpf_reg_state *reg, int size)
+{
+	u64 mask;
+
+	/* clear high bits in bit representation */
+	reg->var_off = tnum_cast(reg->var_off, size);
+
+	/* fix arithmetic bounds */
+	mask = ((u64)1 << (size * 8)) - 1;
+	if ((reg->umin_value & ~mask) == (reg->umax_value & ~mask)) {
+		reg->umin_value &= mask;
+		reg->umax_value &= mask;
+	} else {
+		reg->umin_value = 0;
+		reg->umax_value = mask;
+	}
+	reg->smin_value = reg->umin_value;
+	reg->smax_value = reg->umax_value;
+
+	/* If size is smaller than 32bit register the 32bit register
+	 * values are also truncated so we push 64-bit bounds into
+	 * 32-bit bounds. Above were truncated < 32-bits already.
+	 */
+	if (size >= 4)
+		return;
+	__reg_combine_64_into_32(reg);
+}
+
+static bool bpf_map_is_rdonly(const struct bpf_map *map)
+{
+	/* A map is considered read-only if the following condition are true:
+	 *
+	 * 1) BPF program side cannot change any of the map content. The
+	 *    BPF_F_RDONLY_PROG flag is throughout the lifetime of a map
+	 *    and was set at map creation time.
+	 * 2) The map value(s) have been initialized from user space by a
+	 *    loader and then "frozen", such that no new map update/delete
+	 *    operations from syscall side are possible for the rest of
+	 *    the map's lifetime from that point onwards.
+	 * 3) Any parallel/pending map update/delete operations from syscall
+	 *    side have been completed. Only after that point, it's safe to
+	 *    assume that map value(s) are immutable.
+	 */
+	return (map->map_flags & BPF_F_RDONLY_PROG) &&
+	       READ_ONCE(map->frozen) &&
+	       !bpf_map_write_active(map);
+}
+
+static int bpf_map_direct_read(struct bpf_map *map, int off, int size, u64 *val)
+{
+	void *ptr;
+	u64 addr;
+	int err;
+
+	err = map->ops->map_direct_value_addr(map, &addr, off);
+	if (err)
+		return err;
+	ptr = (void *)(long)addr + off;
+
+	switch (size) {
+	case sizeof(u8):
+		*val = (u64)*(u8 *)ptr;
+		break;
+	case sizeof(u16):
+		*val = (u64)*(u16 *)ptr;
+		break;
+	case sizeof(u32):
+		*val = (u64)*(u32 *)ptr;
+		break;
+	case sizeof(u64):
+		*val = *(u64 *)ptr;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
+				   struct bpf_reg_state *regs,
+				   int regno, int off, int size,
+				   enum bpf_access_type atype,
+				   int value_regno)
+{
+	struct bpf_reg_state *reg = regs + regno;
+	const struct btf_type *t = btf_type_by_id(btf_vmlinux, reg->btf_id);
+	const char *tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+	u32 btf_id;
+	int ret;
+
+	if (off < 0) {
+		verbose(env,
+			"R%d is ptr_%s invalid negative access: off=%d\n",
+			regno, tname, off);
+		return -EACCES;
+	}
+	if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env,
+			"R%d is ptr_%s invalid variable offset: off=%d, var_off=%s\n",
+			regno, tname, off, tn_buf);
+		return -EACCES;
+	}
+
+	if (env->ops->btf_struct_access) {
+		ret = env->ops->btf_struct_access(&env->log, t, off, size,
+						  atype, &btf_id);
+	} else {
+		if (atype != BPF_READ) {
+			verbose(env, "only read is supported\n");
+			return -EACCES;
+		}
+
+		ret = btf_struct_access(&env->log, t, off, size, atype,
+					&btf_id);
+	}
+
+	if (ret < 0)
+		return ret;
+
+	if (atype == BPF_READ && value_regno >= 0)
+		mark_btf_ld_reg(env, regs, value_regno, ret, btf_id);
+
+	return 0;
+}
+
+static int check_ptr_to_map_access(struct bpf_verifier_env *env,
+				   struct bpf_reg_state *regs,
+				   int regno, int off, int size,
+				   enum bpf_access_type atype,
+				   int value_regno)
+{
+	struct bpf_reg_state *reg = regs + regno;
+	struct bpf_map *map = reg->map_ptr;
+	const struct btf_type *t;
+	const char *tname;
+	u32 btf_id;
+	int ret;
+
+	if (!btf_vmlinux) {
+		verbose(env, "map_ptr access not supported without CONFIG_DEBUG_INFO_BTF\n");
+		return -ENOTSUPP;
+	}
+
+	if (!map->ops->map_btf_id || !*map->ops->map_btf_id) {
+		verbose(env, "map_ptr access not supported for map type %d\n",
+			map->map_type);
+		return -ENOTSUPP;
+	}
+
+	t = btf_type_by_id(btf_vmlinux, *map->ops->map_btf_id);
+	tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+
+	if (!env->allow_ptr_to_map_access) {
+		verbose(env,
+			"%s access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN\n",
+			tname);
+		return -EPERM;
+	}
+
+	if (off < 0) {
+		verbose(env, "R%d is %s invalid negative access: off=%d\n",
+			regno, tname, off);
+		return -EACCES;
+	}
+
+	if (atype != BPF_READ) {
+		verbose(env, "only read from %s is supported\n", tname);
+		return -EACCES;
+	}
+
+	ret = btf_struct_access(&env->log, t, off, size, atype, &btf_id);
+	if (ret < 0)
+		return ret;
+
+	if (value_regno >= 0)
+		mark_btf_ld_reg(env, regs, value_regno, ret, btf_id);
+
+	return 0;
+}
+
+/* Check that the stack access at the given offset is within bounds. The
+ * maximum valid offset is -1.
+ *
+ * The minimum valid offset is -MAX_BPF_STACK for writes, and
+ * -state->allocated_stack for reads.
+ */
+static int check_stack_slot_within_bounds(int off,
+					  struct bpf_func_state *state,
+					  enum bpf_access_type t)
+{
+	int min_valid_off;
+
+	if (t == BPF_WRITE)
+		min_valid_off = -MAX_BPF_STACK;
+	else
+		min_valid_off = -state->allocated_stack;
+
+	if (off < min_valid_off || off > -1)
+		return -EACCES;
+	return 0;
+}
+
+/* Check that the stack access at 'regno + off' falls within the maximum stack
+ * bounds.
+ *
+ * 'off' includes `regno->offset`, but not its dynamic part (if any).
+ */
+static int check_stack_access_within_bounds(
+		struct bpf_verifier_env *env,
+		int regno, int off, int access_size,
+		enum stack_access_src src, enum bpf_access_type type)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_reg_state *reg = regs + regno;
+	struct bpf_func_state *state = func(env, reg);
+	int min_off, max_off;
+	int err;
+	char *err_extra;
+
+	if (src == ACCESS_HELPER)
+		/* We don't know if helpers are reading or writing (or both). */
+		err_extra = " indirect access to";
+	else if (type == BPF_READ)
+		err_extra = " read from";
+	else
+		err_extra = " write to";
+
+	if (tnum_is_const(reg->var_off)) {
+		min_off = reg->var_off.value + off;
+		max_off = min_off + access_size;
+	} else {
+		if (reg->smax_value >= BPF_MAX_VAR_OFF ||
+		    reg->smin_value <= -BPF_MAX_VAR_OFF) {
+			verbose(env, "invalid unbounded variable-offset%s stack R%d\n",
+				err_extra, regno);
+			return -EACCES;
+		}
+		min_off = reg->smin_value + off;
+		max_off = reg->smax_value + off + access_size;
+	}
+
+	err = check_stack_slot_within_bounds(min_off, state, type);
+	if (!err && max_off > 0)
+		err = -EINVAL; /* out of stack access into non-negative offsets */
+
+	if (err) {
+		if (tnum_is_const(reg->var_off)) {
+			verbose(env, "invalid%s stack R%d off=%d size=%d\n",
+				err_extra, regno, off, access_size);
+		} else {
+			char tn_buf[48];
+
+			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+			verbose(env, "invalid variable-offset%s stack R%d var_off=%s size=%d\n",
+				err_extra, regno, tn_buf, access_size);
+		}
+	}
+	return err;
+}
+
+/* check whether memory at (regno + off) is accessible for t = (read | write)
+ * if t==write, value_regno is a register which value is stored into memory
+ * if t==read, value_regno is a register which will receive the value from memory
+ * if t==write && value_regno==-1, some unknown value is stored into memory
+ * if t==read && value_regno==-1, don't care what we read from memory
+ */
+static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regno,
+			    int off, int bpf_size, enum bpf_access_type t,
+			    int value_regno, bool strict_alignment_once)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_reg_state *reg = regs + regno;
+	struct bpf_func_state *state;
+	int size, err = 0;
+
+	size = bpf_size_to_bytes(bpf_size);
+	if (size < 0)
+		return size;
+
+	/* alignment checks will add in reg->off themselves */
+	err = check_ptr_alignment(env, reg, off, size, strict_alignment_once);
+	if (err)
+		return err;
+
+	/* for access checks, reg->off is just part of off */
+	off += reg->off;
+
+	if (reg->type == PTR_TO_MAP_VALUE) {
+		if (t == BPF_WRITE && value_regno >= 0 &&
+		    is_pointer_value(env, value_regno)) {
+			verbose(env, "R%d leaks addr into map\n", value_regno);
+			return -EACCES;
+		}
+		err = check_map_access_type(env, regno, off, size, t);
+		if (err)
+			return err;
+		err = check_map_access(env, regno, off, size, false);
+		if (!err && t == BPF_READ && value_regno >= 0) {
+			struct bpf_map *map = reg->map_ptr;
+
+			/* if map is read-only, track its contents as scalars */
+			if (tnum_is_const(reg->var_off) &&
+			    bpf_map_is_rdonly(map) &&
+			    map->ops->map_direct_value_addr) {
+				int map_off = off + reg->var_off.value;
+				u64 val = 0;
+
+				err = bpf_map_direct_read(map, map_off, size,
+							  &val);
+				if (err)
+					return err;
+
+				regs[value_regno].type = SCALAR_VALUE;
+				__mark_reg_known(&regs[value_regno], val);
+			} else {
+				mark_reg_unknown(env, regs, value_regno);
+			}
+		}
+	} else if (reg->type == PTR_TO_MEM) {
+		if (t == BPF_WRITE && value_regno >= 0 &&
+		    is_pointer_value(env, value_regno)) {
+			verbose(env, "R%d leaks addr into mem\n", value_regno);
+			return -EACCES;
+		}
+		err = check_mem_region_access(env, regno, off, size,
+					      reg->mem_size, false);
+		if (!err && t == BPF_READ && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
+	} else if (reg->type == PTR_TO_CTX) {
+		enum bpf_reg_type reg_type = SCALAR_VALUE;
+		u32 btf_id = 0;
+
+		if (t == BPF_WRITE && value_regno >= 0 &&
+		    is_pointer_value(env, value_regno)) {
+			verbose(env, "R%d leaks addr into ctx\n", value_regno);
+			return -EACCES;
+		}
+
+		err = check_ctx_reg(env, reg, regno);
+		if (err < 0)
+			return err;
+
+		err = check_ctx_access(env, insn_idx, off, size, t, &reg_type, &btf_id);
+		if (err)
+			verbose_linfo(env, insn_idx, "; ");
+		if (!err && t == BPF_READ && value_regno >= 0) {
+			/* ctx access returns either a scalar, or a
+			 * PTR_TO_PACKET[_META,_END]. In the latter
+			 * case, we know the offset is zero.
+			 */
+			if (reg_type == SCALAR_VALUE) {
+				mark_reg_unknown(env, regs, value_regno);
+			} else {
+				mark_reg_known_zero(env, regs,
+						    value_regno);
+				if (reg_type_may_be_null(reg_type))
+					regs[value_regno].id = ++env->id_gen;
+				/* A load of ctx field could have different
+				 * actual load size with the one encoded in the
+				 * insn. When the dst is PTR, it is for sure not
+				 * a sub-register.
+				 */
+				regs[value_regno].subreg_def = DEF_NOT_SUBREG;
+				if (reg_type == PTR_TO_BTF_ID ||
+				    reg_type == PTR_TO_BTF_ID_OR_NULL)
+					regs[value_regno].btf_id = btf_id;
+			}
+			regs[value_regno].type = reg_type;
+		}
+
+	} else if (reg->type == PTR_TO_STACK) {
+		/* Basic bounds checks. */
+		err = check_stack_access_within_bounds(env, regno, off, size, ACCESS_DIRECT, t);
+		if (err)
+			return err;
+
+		state = func(env, reg);
+		err = update_stack_depth(env, state, off);
+		if (err)
+			return err;
+
+		if (t == BPF_READ)
+			err = check_stack_read(env, regno, off, size,
+					       value_regno);
+		else
+			err = check_stack_write(env, regno, off, size,
+						value_regno, insn_idx);
+	} else if (reg_is_pkt_pointer(reg)) {
+		if (t == BPF_WRITE && !may_access_direct_pkt_data(env, NULL, t)) {
+			verbose(env, "cannot write into packet\n");
+			return -EACCES;
+		}
+		if (t == BPF_WRITE && value_regno >= 0 &&
+		    is_pointer_value(env, value_regno)) {
+			verbose(env, "R%d leaks addr into packet\n",
+				value_regno);
+			return -EACCES;
+		}
+		err = check_packet_access(env, regno, off, size, false);
+		if (!err && t == BPF_READ && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
+	} else if (reg->type == PTR_TO_FLOW_KEYS) {
+		if (t == BPF_WRITE && value_regno >= 0 &&
+		    is_pointer_value(env, value_regno)) {
+			verbose(env, "R%d leaks addr into flow keys\n",
+				value_regno);
+			return -EACCES;
+		}
+
+		err = check_flow_keys_access(env, off, size);
+		if (!err && t == BPF_READ && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
+	} else if (type_is_sk_pointer(reg->type)) {
+		if (t == BPF_WRITE) {
+			verbose(env, "R%d cannot write into %s\n",
+				regno, reg_type_str[reg->type]);
+			return -EACCES;
+		}
+		err = check_sock_access(env, insn_idx, regno, off, size, t);
+		if (!err && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
+	} else if (reg->type == PTR_TO_TP_BUFFER) {
+		err = check_tp_buffer_access(env, reg, regno, off, size);
+		if (!err && t == BPF_READ && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
+	} else if (reg->type == PTR_TO_BTF_ID) {
+		err = check_ptr_to_btf_access(env, regs, regno, off, size, t,
+					      value_regno);
+	} else if (reg->type == CONST_PTR_TO_MAP) {
+		err = check_ptr_to_map_access(env, regs, regno, off, size, t,
+					      value_regno);
+	} else if (reg->type == PTR_TO_RDONLY_BUF) {
+		if (t == BPF_WRITE) {
+			verbose(env, "R%d cannot write into %s\n",
+				regno, reg_type_str[reg->type]);
+			return -EACCES;
+		}
+		err = check_buffer_access(env, reg, regno, off, size, false,
+					  "rdonly",
+					  &env->prog->aux->max_rdonly_access);
+		if (!err && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
+	} else if (reg->type == PTR_TO_RDWR_BUF) {
+		err = check_buffer_access(env, reg, regno, off, size, false,
+					  "rdwr",
+					  &env->prog->aux->max_rdwr_access);
+		if (!err && t == BPF_READ && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
+	} else {
+		verbose(env, "R%d invalid mem access '%s'\n", regno,
+			reg_type_str[reg->type]);
+		return -EACCES;
+	}
+
+	if (!err && size < BPF_REG_SIZE && value_regno >= 0 && t == BPF_READ &&
+	    regs[value_regno].type == SCALAR_VALUE) {
+		/* b/h/w load zero-extends, mark upper bits as known 0 */
+		coerce_reg_to_size(&regs[value_regno], size);
+	}
+	return err;
+}
+
+static int check_xadd(struct bpf_verifier_env *env, int insn_idx, struct bpf_insn *insn)
+{
+	int err;
+
+	if ((BPF_SIZE(insn->code) != BPF_W && BPF_SIZE(insn->code) != BPF_DW) ||
+	    insn->imm != 0) {
+		verbose(env, "BPF_XADD uses reserved fields\n");
+		return -EINVAL;
+	}
+
+	/* check src1 operand */
+	err = check_reg_arg(env, insn->src_reg, SRC_OP);
+	if (err)
+		return err;
+
+	/* check src2 operand */
+	err = check_reg_arg(env, insn->dst_reg, SRC_OP);
+	if (err)
+		return err;
+
+	if (is_pointer_value(env, insn->src_reg)) {
+		verbose(env, "R%d leaks addr into mem\n", insn->src_reg);
+		return -EACCES;
+	}
+
+	if (is_ctx_reg(env, insn->dst_reg) ||
+	    is_pkt_reg(env, insn->dst_reg) ||
+	    is_flow_key_reg(env, insn->dst_reg) ||
+	    is_sk_reg(env, insn->dst_reg)) {
+		verbose(env, "BPF_XADD stores into R%d %s is not allowed\n",
+			insn->dst_reg,
+			reg_type_str[reg_state(env, insn->dst_reg)->type]);
+		return -EACCES;
+	}
+
+	/* check whether atomic_add can read the memory */
+	err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off,
+			       BPF_SIZE(insn->code), BPF_READ, -1, true);
+	if (err)
+		return err;
+
+	/* check whether atomic_add can write into the same memory */
+	return check_mem_access(env, insn_idx, insn->dst_reg, insn->off,
+				BPF_SIZE(insn->code), BPF_WRITE, -1, true);
+}
+
+/* When register 'regno' is used to read the stack (either directly or through
+ * a helper function) make sure that it's within stack boundary and, depending
+ * on the access type, that all elements of the stack are initialized.
+ *
+ * 'off' includes 'regno->off', but not its dynamic part (if any).
+ *
+ * All registers that have been spilled on the stack in the slots within the
+ * read offsets are marked as read.
+ */
+static int check_stack_range_initialized(
+		struct bpf_verifier_env *env, int regno, int off,
+		int access_size, bool zero_size_allowed,
+		enum stack_access_src type, struct bpf_call_arg_meta *meta)
+{
+	struct bpf_reg_state *reg = reg_state(env, regno);
+	struct bpf_func_state *state = func(env, reg);
+	int err, min_off, max_off, i, j, slot, spi;
+	char *err_extra = type == ACCESS_HELPER ? " indirect" : "";
+	enum bpf_access_type bounds_check_type;
+	/* Some accesses can write anything into the stack, others are
+	 * read-only.
+	 */
+	bool clobber = false;
+
+	if (access_size == 0 && !zero_size_allowed) {
+		verbose(env, "invalid zero-sized read\n");
+		return -EACCES;
+	}
+
+	if (type == ACCESS_HELPER) {
+		/* The bounds checks for writes are more permissive than for
+		 * reads. However, if raw_mode is not set, we'll do extra
+		 * checks below.
+		 */
+		bounds_check_type = BPF_WRITE;
+		clobber = true;
+	} else {
+		bounds_check_type = BPF_READ;
+	}
+	err = check_stack_access_within_bounds(env, regno, off, access_size,
+					       type, bounds_check_type);
+	if (err)
+		return err;
+
+
+	if (tnum_is_const(reg->var_off)) {
+		min_off = max_off = reg->var_off.value + off;
+	} else {
+		/* Variable offset is prohibited for unprivileged mode for
+		 * simplicity since it requires corresponding support in
+		 * Spectre masking for stack ALU.
+		 * See also retrieve_ptr_limit().
+		 */
+		if (!env->bypass_spec_v1) {
+			char tn_buf[48];
+
+			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+			verbose(env, "R%d%s variable offset stack access prohibited for !root, var_off=%s\n",
+				regno, err_extra, tn_buf);
+			return -EACCES;
+		}
+		/* Only initialized buffer on stack is allowed to be accessed
+		 * with variable offset. With uninitialized buffer it's hard to
+		 * guarantee that whole memory is marked as initialized on
+		 * helper return since specific bounds are unknown what may
+		 * cause uninitialized stack leaking.
+		 */
+		if (meta && meta->raw_mode)
+			meta = NULL;
+
+		min_off = reg->smin_value + off;
+		max_off = reg->smax_value + off;
+	}
+
+	if (meta && meta->raw_mode) {
+		meta->access_size = access_size;
+		meta->regno = regno;
+		return 0;
+	}
+
+	for (i = min_off; i < max_off + access_size; i++) {
+		u8 *stype;
+
+		slot = -i - 1;
+		spi = slot / BPF_REG_SIZE;
+		if (state->allocated_stack <= slot)
+			goto err;
+		stype = &state->stack[spi].slot_type[slot % BPF_REG_SIZE];
+		if (*stype == STACK_MISC)
+			goto mark;
+		if (*stype == STACK_ZERO) {
+			if (clobber) {
+				/* helper can write anything into the stack */
+				*stype = STACK_MISC;
+			}
+			goto mark;
+		}
+
+		if (is_spilled_reg(&state->stack[spi]) &&
+		    state->stack[spi].spilled_ptr.type == PTR_TO_BTF_ID)
+			goto mark;
+
+		if (is_spilled_reg(&state->stack[spi]) &&
+		    (state->stack[spi].spilled_ptr.type == SCALAR_VALUE ||
+		     env->allow_ptr_leaks)) {
+			if (clobber) {
+				__mark_reg_unknown(env, &state->stack[spi].spilled_ptr);
+				for (j = 0; j < BPF_REG_SIZE; j++)
+					scrub_spilled_slot(&state->stack[spi].slot_type[j]);
+			}
+			goto mark;
+		}
+
+err:
+		if (tnum_is_const(reg->var_off)) {
+			verbose(env, "invalid%s read from stack R%d off %d+%d size %d\n",
+				err_extra, regno, min_off, i - min_off, access_size);
+		} else {
+			char tn_buf[48];
+
+			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+			verbose(env, "invalid%s read from stack R%d var_off %s+%d size %d\n",
+				err_extra, regno, tn_buf, i - min_off, access_size);
+		}
+		return -EACCES;
+mark:
+		/* reading any byte out of 8-byte 'spill_slot' will cause
+		 * the whole slot to be marked as 'read'
+		 */
+		mark_reg_read(env, &state->stack[spi].spilled_ptr,
+			      state->stack[spi].spilled_ptr.parent,
+			      REG_LIVE_READ64);
+	}
+	return update_stack_depth(env, state, min_off);
+}
+
+static int check_helper_mem_access(struct bpf_verifier_env *env, int regno,
+				   int access_size, bool zero_size_allowed,
+				   struct bpf_call_arg_meta *meta)
+{
+	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+
+	switch (reg->type) {
+	case PTR_TO_PACKET:
+	case PTR_TO_PACKET_META:
+		return check_packet_access(env, regno, reg->off, access_size,
+					   zero_size_allowed);
+	case PTR_TO_MAP_VALUE:
+		if (check_map_access_type(env, regno, reg->off, access_size,
+					  meta && meta->raw_mode ? BPF_WRITE :
+					  BPF_READ))
+			return -EACCES;
+		return check_map_access(env, regno, reg->off, access_size,
+					zero_size_allowed);
+	case PTR_TO_MEM:
+		return check_mem_region_access(env, regno, reg->off,
+					       access_size, reg->mem_size,
+					       zero_size_allowed);
+	case PTR_TO_RDONLY_BUF:
+		if (meta && meta->raw_mode)
+			return -EACCES;
+		return check_buffer_access(env, reg, regno, reg->off,
+					   access_size, zero_size_allowed,
+					   "rdonly",
+					   &env->prog->aux->max_rdonly_access);
+	case PTR_TO_RDWR_BUF:
+		return check_buffer_access(env, reg, regno, reg->off,
+					   access_size, zero_size_allowed,
+					   "rdwr",
+					   &env->prog->aux->max_rdwr_access);
+	case PTR_TO_STACK:
+		return check_stack_range_initialized(
+				env,
+				regno, reg->off, access_size,
+				zero_size_allowed, ACCESS_HELPER, meta);
+	default: /* scalar_value or invalid ptr */
+		/* Allow zero-byte read from NULL, regardless of pointer type */
+		if (zero_size_allowed && access_size == 0 &&
+		    register_is_null(reg))
+			return 0;
+
+		verbose(env, "R%d type=%s expected=%s\n", regno,
+			reg_type_str[reg->type],
+			reg_type_str[PTR_TO_STACK]);
+		return -EACCES;
+	}
+}
+
+/* Implementation details:
+ * bpf_map_lookup returns PTR_TO_MAP_VALUE_OR_NULL
+ * Two bpf_map_lookups (even with the same key) will have different reg->id.
+ * For traditional PTR_TO_MAP_VALUE the verifier clears reg->id after
+ * value_or_null->value transition, since the verifier only cares about
+ * the range of access to valid map value pointer and doesn't care about actual
+ * address of the map element.
+ * For maps with 'struct bpf_spin_lock' inside map value the verifier keeps
+ * reg->id > 0 after value_or_null->value transition. By doing so
+ * two bpf_map_lookups will be considered two different pointers that
+ * point to different bpf_spin_locks.
+ * The verifier allows taking only one bpf_spin_lock at a time to avoid
+ * dead-locks.
+ * Since only one bpf_spin_lock is allowed the checks are simpler than
+ * reg_is_refcounted() logic. The verifier needs to remember only
+ * one spin_lock instead of array of acquired_refs.
+ * cur_state->active_spin_lock remembers which map value element got locked
+ * and clears it after bpf_spin_unlock.
+ */
+static int process_spin_lock(struct bpf_verifier_env *env, int regno,
+			     bool is_lock)
+{
+	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	struct bpf_verifier_state *cur = env->cur_state;
+	bool is_const = tnum_is_const(reg->var_off);
+	struct bpf_map *map = reg->map_ptr;
+	u64 val = reg->var_off.value;
+
+	if (!is_const) {
+		verbose(env,
+			"R%d doesn't have constant offset. bpf_spin_lock has to be at the constant offset\n",
+			regno);
+		return -EINVAL;
+	}
+	if (!map->btf) {
+		verbose(env,
+			"map '%s' has to have BTF in order to use bpf_spin_lock\n",
+			map->name);
+		return -EINVAL;
+	}
+	if (!map_value_has_spin_lock(map)) {
+		if (map->spin_lock_off == -E2BIG)
+			verbose(env,
+				"map '%s' has more than one 'struct bpf_spin_lock'\n",
+				map->name);
+		else if (map->spin_lock_off == -ENOENT)
+			verbose(env,
+				"map '%s' doesn't have 'struct bpf_spin_lock'\n",
+				map->name);
+		else
+			verbose(env,
+				"map '%s' is not a struct type or bpf_spin_lock is mangled\n",
+				map->name);
+		return -EINVAL;
+	}
+	if (map->spin_lock_off != val + reg->off) {
+		verbose(env, "off %lld doesn't point to 'struct bpf_spin_lock'\n",
+			val + reg->off);
+		return -EINVAL;
+	}
+	if (is_lock) {
+		if (cur->active_spin_lock) {
+			verbose(env,
+				"Locking two bpf_spin_locks are not allowed\n");
+			return -EINVAL;
+		}
+		cur->active_spin_lock = reg->id;
+	} else {
+		if (!cur->active_spin_lock) {
+			verbose(env, "bpf_spin_unlock without taking a lock\n");
+			return -EINVAL;
+		}
+		if (cur->active_spin_lock != reg->id) {
+			verbose(env, "bpf_spin_unlock of different lock\n");
+			return -EINVAL;
+		}
+		cur->active_spin_lock = 0;
+	}
+	return 0;
+}
+
+static bool arg_type_is_mem_ptr(enum bpf_arg_type type)
+{
+	return type == ARG_PTR_TO_MEM ||
+	       type == ARG_PTR_TO_MEM_OR_NULL ||
+	       type == ARG_PTR_TO_UNINIT_MEM;
+}
+
+static bool arg_type_is_mem_size(enum bpf_arg_type type)
+{
+	return type == ARG_CONST_SIZE ||
+	       type == ARG_CONST_SIZE_OR_ZERO;
+}
+
+static bool arg_type_is_alloc_size(enum bpf_arg_type type)
+{
+	return type == ARG_CONST_ALLOC_SIZE_OR_ZERO;
+}
+
+static bool arg_type_is_int_ptr(enum bpf_arg_type type)
+{
+	return type == ARG_PTR_TO_INT ||
+	       type == ARG_PTR_TO_LONG;
+}
+
+static int int_ptr_type_to_size(enum bpf_arg_type type)
+{
+	if (type == ARG_PTR_TO_INT)
+		return sizeof(u32);
+	else if (type == ARG_PTR_TO_LONG)
+		return sizeof(u64);
+
+	return -EINVAL;
+}
+
+static int resolve_map_arg_type(struct bpf_verifier_env *env,
+				 const struct bpf_call_arg_meta *meta,
+				 enum bpf_arg_type *arg_type)
+{
+	if (!meta->map_ptr) {
+		/* kernel subsystem misconfigured verifier */
+		verbose(env, "invalid map_ptr to access map->type\n");
+		return -EACCES;
+	}
+
+	switch (meta->map_ptr->map_type) {
+	case BPF_MAP_TYPE_SOCKMAP:
+	case BPF_MAP_TYPE_SOCKHASH:
+		if (*arg_type == ARG_PTR_TO_MAP_VALUE) {
+			*arg_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON;
+		} else {
+			verbose(env, "invalid arg_type for sockmap/sockhash\n");
+			return -EINVAL;
+		}
+		break;
+
+	default:
+		break;
+	}
+	return 0;
+}
+
+struct bpf_reg_types {
+	const enum bpf_reg_type types[10];
+	u32 *btf_id;
+};
+
+static const struct bpf_reg_types map_key_value_types = {
+	.types = {
+		PTR_TO_STACK,
+		PTR_TO_PACKET,
+		PTR_TO_PACKET_META,
+		PTR_TO_MAP_VALUE,
+	},
+};
+
+static const struct bpf_reg_types sock_types = {
+	.types = {
+		PTR_TO_SOCK_COMMON,
+		PTR_TO_SOCKET,
+		PTR_TO_TCP_SOCK,
+		PTR_TO_XDP_SOCK,
+	},
+};
+
+#ifdef CONFIG_NET
+static const struct bpf_reg_types btf_id_sock_common_types = {
+	.types = {
+		PTR_TO_SOCK_COMMON,
+		PTR_TO_SOCKET,
+		PTR_TO_TCP_SOCK,
+		PTR_TO_XDP_SOCK,
+		PTR_TO_BTF_ID,
+	},
+	.btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
+};
+#endif
+
+static const struct bpf_reg_types mem_types = {
+	.types = {
+		PTR_TO_STACK,
+		PTR_TO_PACKET,
+		PTR_TO_PACKET_META,
+		PTR_TO_MAP_VALUE,
+		PTR_TO_MEM,
+		PTR_TO_RDONLY_BUF,
+		PTR_TO_RDWR_BUF,
+	},
+};
+
+static const struct bpf_reg_types int_ptr_types = {
+	.types = {
+		PTR_TO_STACK,
+		PTR_TO_PACKET,
+		PTR_TO_PACKET_META,
+		PTR_TO_MAP_VALUE,
+	},
+};
+
+static const struct bpf_reg_types fullsock_types = { .types = { PTR_TO_SOCKET } };
+static const struct bpf_reg_types scalar_types = { .types = { SCALAR_VALUE } };
+static const struct bpf_reg_types context_types = { .types = { PTR_TO_CTX } };
+static const struct bpf_reg_types alloc_mem_types = { .types = { PTR_TO_MEM } };
+static const struct bpf_reg_types const_map_ptr_types = { .types = { CONST_PTR_TO_MAP } };
+static const struct bpf_reg_types btf_ptr_types = { .types = { PTR_TO_BTF_ID } };
+static const struct bpf_reg_types spin_lock_types = { .types = { PTR_TO_MAP_VALUE } };
+static const struct bpf_reg_types percpu_btf_ptr_types = { .types = { PTR_TO_PERCPU_BTF_ID } };
+
+static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = {
+	[ARG_PTR_TO_MAP_KEY]		= &map_key_value_types,
+	[ARG_PTR_TO_MAP_VALUE]		= &map_key_value_types,
+	[ARG_PTR_TO_UNINIT_MAP_VALUE]	= &map_key_value_types,
+	[ARG_PTR_TO_MAP_VALUE_OR_NULL]	= &map_key_value_types,
+	[ARG_CONST_SIZE]		= &scalar_types,
+	[ARG_CONST_SIZE_OR_ZERO]	= &scalar_types,
+	[ARG_CONST_ALLOC_SIZE_OR_ZERO]	= &scalar_types,
+	[ARG_CONST_MAP_PTR]		= &const_map_ptr_types,
+	[ARG_PTR_TO_CTX]		= &context_types,
+	[ARG_PTR_TO_CTX_OR_NULL]	= &context_types,
+	[ARG_PTR_TO_SOCK_COMMON]	= &sock_types,
+#ifdef CONFIG_NET
+	[ARG_PTR_TO_BTF_ID_SOCK_COMMON]	= &btf_id_sock_common_types,
+#endif
+	[ARG_PTR_TO_SOCKET]		= &fullsock_types,
+	[ARG_PTR_TO_SOCKET_OR_NULL]	= &fullsock_types,
+	[ARG_PTR_TO_BTF_ID]		= &btf_ptr_types,
+	[ARG_PTR_TO_SPIN_LOCK]		= &spin_lock_types,
+	[ARG_PTR_TO_MEM]		= &mem_types,
+	[ARG_PTR_TO_MEM_OR_NULL]	= &mem_types,
+	[ARG_PTR_TO_UNINIT_MEM]		= &mem_types,
+	[ARG_PTR_TO_ALLOC_MEM]		= &alloc_mem_types,
+	[ARG_PTR_TO_ALLOC_MEM_OR_NULL]	= &alloc_mem_types,
+	[ARG_PTR_TO_INT]		= &int_ptr_types,
+	[ARG_PTR_TO_LONG]		= &int_ptr_types,
+	[ARG_PTR_TO_PERCPU_BTF_ID]	= &percpu_btf_ptr_types,
+};
+
+static int check_reg_type(struct bpf_verifier_env *env, u32 regno,
+			  enum bpf_arg_type arg_type,
+			  const u32 *arg_btf_id)
+{
+	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	enum bpf_reg_type expected, type = reg->type;
+	const struct bpf_reg_types *compatible;
+	int i, j;
+
+	compatible = compatible_reg_types[arg_type];
+	if (!compatible) {
+		verbose(env, "verifier internal error: unsupported arg type %d\n", arg_type);
+		return -EFAULT;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(compatible->types); i++) {
+		expected = compatible->types[i];
+		if (expected == NOT_INIT)
+			break;
+
+		if (type == expected)
+			goto found;
+	}
+
+	verbose(env, "R%d type=%s expected=", regno, reg_type_str[type]);
+	for (j = 0; j + 1 < i; j++)
+		verbose(env, "%s, ", reg_type_str[compatible->types[j]]);
+	verbose(env, "%s\n", reg_type_str[compatible->types[j]]);
+	return -EACCES;
+
+found:
+	if (type == PTR_TO_BTF_ID) {
+		if (!arg_btf_id) {
+			if (!compatible->btf_id) {
+				verbose(env, "verifier internal error: missing arg compatible BTF ID\n");
+				return -EFAULT;
+			}
+			arg_btf_id = compatible->btf_id;
+		}
+
+		if (!btf_struct_ids_match(&env->log, reg->off, reg->btf_id,
+					  *arg_btf_id)) {
+			verbose(env, "R%d is of type %s but %s is expected\n",
+				regno, kernel_type_name(reg->btf_id),
+				kernel_type_name(*arg_btf_id));
+			return -EACCES;
+		}
+
+		if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+			verbose(env, "R%d is a pointer to in-kernel struct with non-zero offset\n",
+				regno);
+			return -EACCES;
+		}
+	}
+
+	return 0;
+}
+
+static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
+			  struct bpf_call_arg_meta *meta,
+			  const struct bpf_func_proto *fn)
+{
+	u32 regno = BPF_REG_1 + arg;
+	struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+	enum bpf_arg_type arg_type = fn->arg_type[arg];
+	enum bpf_reg_type type = reg->type;
+	int err = 0;
+
+	if (arg_type == ARG_DONTCARE)
+		return 0;
+
+	err = check_reg_arg(env, regno, SRC_OP);
+	if (err)
+		return err;
+
+	if (arg_type == ARG_ANYTHING) {
+		if (is_pointer_value(env, regno)) {
+			verbose(env, "R%d leaks addr into helper function\n",
+				regno);
+			return -EACCES;
+		}
+		return 0;
+	}
+
+	if (type_is_pkt_pointer(type) &&
+	    !may_access_direct_pkt_data(env, meta, BPF_READ)) {
+		verbose(env, "helper access to the packet is not allowed\n");
+		return -EACCES;
+	}
+
+	if (arg_type == ARG_PTR_TO_MAP_VALUE ||
+	    arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE ||
+	    arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL) {
+		err = resolve_map_arg_type(env, meta, &arg_type);
+		if (err)
+			return err;
+	}
+
+	if (register_is_null(reg) && arg_type_may_be_null(arg_type))
+		/* A NULL register has a SCALAR_VALUE type, so skip
+		 * type checking.
+		 */
+		goto skip_type_check;
+
+	err = check_reg_type(env, regno, arg_type, fn->arg_btf_id[arg]);
+	if (err)
+		return err;
+
+	if (type == PTR_TO_CTX) {
+		err = check_ctx_reg(env, reg, regno);
+		if (err < 0)
+			return err;
+	}
+
+skip_type_check:
+	if (reg->ref_obj_id) {
+		if (meta->ref_obj_id) {
+			verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n",
+				regno, reg->ref_obj_id,
+				meta->ref_obj_id);
+			return -EFAULT;
+		}
+		meta->ref_obj_id = reg->ref_obj_id;
+	}
+
+	if (arg_type == ARG_CONST_MAP_PTR) {
+		/* bpf_map_xxx(map_ptr) call: remember that map_ptr */
+		meta->map_ptr = reg->map_ptr;
+	} else if (arg_type == ARG_PTR_TO_MAP_KEY) {
+		/* bpf_map_xxx(..., map_ptr, ..., key) call:
+		 * check that [key, key + map->key_size) are within
+		 * stack limits and initialized
+		 */
+		if (!meta->map_ptr) {
+			/* in function declaration map_ptr must come before
+			 * map_key, so that it's verified and known before
+			 * we have to check map_key here. Otherwise it means
+			 * that kernel subsystem misconfigured verifier
+			 */
+			verbose(env, "invalid map_ptr to access map->key\n");
+			return -EACCES;
+		}
+		err = check_helper_mem_access(env, regno,
+					      meta->map_ptr->key_size, false,
+					      NULL);
+	} else if (arg_type == ARG_PTR_TO_MAP_VALUE ||
+		   (arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL &&
+		    !register_is_null(reg)) ||
+		   arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE) {
+		/* bpf_map_xxx(..., map_ptr, ..., value) call:
+		 * check [value, value + map->value_size) validity
+		 */
+		if (!meta->map_ptr) {
+			/* kernel subsystem misconfigured verifier */
+			verbose(env, "invalid map_ptr to access map->value\n");
+			return -EACCES;
+		}
+		meta->raw_mode = (arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE);
+		err = check_helper_mem_access(env, regno,
+					      meta->map_ptr->value_size, false,
+					      meta);
+	} else if (arg_type == ARG_PTR_TO_PERCPU_BTF_ID) {
+		if (!reg->btf_id) {
+			verbose(env, "Helper has invalid btf_id in R%d\n", regno);
+			return -EACCES;
+		}
+		meta->ret_btf_id = reg->btf_id;
+	} else if (arg_type == ARG_PTR_TO_SPIN_LOCK) {
+		if (meta->func_id == BPF_FUNC_spin_lock) {
+			if (process_spin_lock(env, regno, true))
+				return -EACCES;
+		} else if (meta->func_id == BPF_FUNC_spin_unlock) {
+			if (process_spin_lock(env, regno, false))
+				return -EACCES;
+		} else {
+			verbose(env, "verifier internal error\n");
+			return -EFAULT;
+		}
+	} else if (arg_type_is_mem_ptr(arg_type)) {
+		/* The access to this pointer is only checked when we hit the
+		 * next is_mem_size argument below.
+		 */
+		meta->raw_mode = (arg_type == ARG_PTR_TO_UNINIT_MEM);
+	} else if (arg_type_is_mem_size(arg_type)) {
+		bool zero_size_allowed = (arg_type == ARG_CONST_SIZE_OR_ZERO);
+
+		/* This is used to refine r0 return value bounds for helpers
+		 * that enforce this value as an upper bound on return values.
+		 * See do_refine_retval_range() for helpers that can refine
+		 * the return value. C type of helper is u32 so we pull register
+		 * bound from umax_value however, if negative verifier errors
+		 * out. Only upper bounds can be learned because retval is an
+		 * int type and negative retvals are allowed.
+		 */
+		meta->msize_max_value = reg->umax_value;
+
+		/* The register is SCALAR_VALUE; the access check
+		 * happens using its boundaries.
+		 */
+		if (!tnum_is_const(reg->var_off))
+			/* For unprivileged variable accesses, disable raw
+			 * mode so that the program is required to
+			 * initialize all the memory that the helper could
+			 * just partially fill up.
+			 */
+			meta = NULL;
+
+		if (reg->smin_value < 0) {
+			verbose(env, "R%d min value is negative, either use unsigned or 'var &= const'\n",
+				regno);
+			return -EACCES;
+		}
+
+		if (reg->umin_value == 0) {
+			err = check_helper_mem_access(env, regno - 1, 0,
+						      zero_size_allowed,
+						      meta);
+			if (err)
+				return err;
+		}
+
+		if (reg->umax_value >= BPF_MAX_VAR_SIZ) {
+			verbose(env, "R%d unbounded memory access, use 'var &= const' or 'if (var < const)'\n",
+				regno);
+			return -EACCES;
+		}
+		err = check_helper_mem_access(env, regno - 1,
+					      reg->umax_value,
+					      zero_size_allowed, meta);
+		if (!err)
+			err = mark_chain_precision(env, regno);
+	} else if (arg_type_is_alloc_size(arg_type)) {
+		if (!tnum_is_const(reg->var_off)) {
+			verbose(env, "R%d unbounded size, use 'var &= const' or 'if (var < const)'\n",
+				regno);
+			return -EACCES;
+		}
+		meta->mem_size = reg->var_off.value;
+	} else if (arg_type_is_int_ptr(arg_type)) {
+		int size = int_ptr_type_to_size(arg_type);
+
+		err = check_helper_mem_access(env, regno, size, false, meta);
+		if (err)
+			return err;
+		err = check_ptr_alignment(env, reg, 0, size, true);
+	}
+
+	return err;
+}
+
+static bool may_update_sockmap(struct bpf_verifier_env *env, int func_id)
+{
+	enum bpf_attach_type eatype = env->prog->expected_attach_type;
+	enum bpf_prog_type type = resolve_prog_type(env->prog);
+
+	if (func_id != BPF_FUNC_map_update_elem)
+		return false;
+
+	/* It's not possible to get access to a locked struct sock in these
+	 * contexts, so updating is safe.
+	 */
+	switch (type) {
+	case BPF_PROG_TYPE_TRACING:
+		if (eatype == BPF_TRACE_ITER)
+			return true;
+		break;
+	case BPF_PROG_TYPE_SOCKET_FILTER:
+	case BPF_PROG_TYPE_SCHED_CLS:
+	case BPF_PROG_TYPE_SCHED_ACT:
+	case BPF_PROG_TYPE_XDP:
+	case BPF_PROG_TYPE_SK_REUSEPORT:
+	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+	case BPF_PROG_TYPE_SK_LOOKUP:
+		return true;
+	default:
+		break;
+	}
+
+	verbose(env, "cannot update sockmap in this context\n");
+	return false;
+}
+
+static bool allow_tail_call_in_subprogs(struct bpf_verifier_env *env)
+{
+	return env->prog->jit_requested && IS_ENABLED(CONFIG_X86_64);
+}
+
+static int check_map_func_compatibility(struct bpf_verifier_env *env,
+					struct bpf_map *map, int func_id)
+{
+	if (!map)
+		return 0;
+
+	/* We need a two way check, first is from map perspective ... */
+	switch (map->map_type) {
+	case BPF_MAP_TYPE_PROG_ARRAY:
+		if (func_id != BPF_FUNC_tail_call)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
+		if (func_id != BPF_FUNC_perf_event_read &&
+		    func_id != BPF_FUNC_perf_event_output &&
+		    func_id != BPF_FUNC_skb_output &&
+		    func_id != BPF_FUNC_perf_event_read_value &&
+		    func_id != BPF_FUNC_xdp_output)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_RINGBUF:
+		if (func_id != BPF_FUNC_ringbuf_output &&
+		    func_id != BPF_FUNC_ringbuf_reserve &&
+		    func_id != BPF_FUNC_ringbuf_query)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_STACK_TRACE:
+		if (func_id != BPF_FUNC_get_stackid)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_CGROUP_ARRAY:
+		if (func_id != BPF_FUNC_skb_under_cgroup &&
+		    func_id != BPF_FUNC_current_task_under_cgroup)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_CGROUP_STORAGE:
+	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
+		if (func_id != BPF_FUNC_get_local_storage)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_DEVMAP:
+	case BPF_MAP_TYPE_DEVMAP_HASH:
+		if (func_id != BPF_FUNC_redirect_map &&
+		    func_id != BPF_FUNC_map_lookup_elem)
+			goto error;
+		break;
+	/* Restrict bpf side of cpumap and xskmap, open when use-cases
+	 * appear.
+	 */
+	case BPF_MAP_TYPE_CPUMAP:
+		if (func_id != BPF_FUNC_redirect_map)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_XSKMAP:
+		if (func_id != BPF_FUNC_redirect_map &&
+		    func_id != BPF_FUNC_map_lookup_elem)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
+	case BPF_MAP_TYPE_HASH_OF_MAPS:
+		if (func_id != BPF_FUNC_map_lookup_elem)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_SOCKMAP:
+		if (func_id != BPF_FUNC_sk_redirect_map &&
+		    func_id != BPF_FUNC_sock_map_update &&
+		    func_id != BPF_FUNC_map_delete_elem &&
+		    func_id != BPF_FUNC_msg_redirect_map &&
+		    func_id != BPF_FUNC_sk_select_reuseport &&
+		    func_id != BPF_FUNC_map_lookup_elem &&
+		    !may_update_sockmap(env, func_id))
+			goto error;
+		break;
+	case BPF_MAP_TYPE_SOCKHASH:
+		if (func_id != BPF_FUNC_sk_redirect_hash &&
+		    func_id != BPF_FUNC_sock_hash_update &&
+		    func_id != BPF_FUNC_map_delete_elem &&
+		    func_id != BPF_FUNC_msg_redirect_hash &&
+		    func_id != BPF_FUNC_sk_select_reuseport &&
+		    func_id != BPF_FUNC_map_lookup_elem &&
+		    !may_update_sockmap(env, func_id))
+			goto error;
+		break;
+	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
+		if (func_id != BPF_FUNC_sk_select_reuseport)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_QUEUE:
+	case BPF_MAP_TYPE_STACK:
+		if (func_id != BPF_FUNC_map_peek_elem &&
+		    func_id != BPF_FUNC_map_pop_elem &&
+		    func_id != BPF_FUNC_map_push_elem)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_SK_STORAGE:
+		if (func_id != BPF_FUNC_sk_storage_get &&
+		    func_id != BPF_FUNC_sk_storage_delete)
+			goto error;
+		break;
+	case BPF_MAP_TYPE_INODE_STORAGE:
+		if (func_id != BPF_FUNC_inode_storage_get &&
+		    func_id != BPF_FUNC_inode_storage_delete)
+			goto error;
+		break;
+	default:
+		break;
+	}
+
+	/* ... and second from the function itself. */
+	switch (func_id) {
+	case BPF_FUNC_tail_call:
+		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
+			goto error;
+		if (env->subprog_cnt > 1 && !allow_tail_call_in_subprogs(env)) {
+			verbose(env, "tail_calls are not allowed in non-JITed programs with bpf-to-bpf calls\n");
+			return -EINVAL;
+		}
+		break;
+	case BPF_FUNC_perf_event_read:
+	case BPF_FUNC_perf_event_output:
+	case BPF_FUNC_perf_event_read_value:
+	case BPF_FUNC_skb_output:
+	case BPF_FUNC_xdp_output:
+		if (map->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY)
+			goto error;
+		break;
+	case BPF_FUNC_ringbuf_output:
+	case BPF_FUNC_ringbuf_reserve:
+	case BPF_FUNC_ringbuf_query:
+		if (map->map_type != BPF_MAP_TYPE_RINGBUF)
+			goto error;
+		break;
+	case BPF_FUNC_get_stackid:
+		if (map->map_type != BPF_MAP_TYPE_STACK_TRACE)
+			goto error;
+		break;
+	case BPF_FUNC_current_task_under_cgroup:
+	case BPF_FUNC_skb_under_cgroup:
+		if (map->map_type != BPF_MAP_TYPE_CGROUP_ARRAY)
+			goto error;
+		break;
+	case BPF_FUNC_redirect_map:
+		if (map->map_type != BPF_MAP_TYPE_DEVMAP &&
+		    map->map_type != BPF_MAP_TYPE_DEVMAP_HASH &&
+		    map->map_type != BPF_MAP_TYPE_CPUMAP &&
+		    map->map_type != BPF_MAP_TYPE_XSKMAP)
+			goto error;
+		break;
+	case BPF_FUNC_sk_redirect_map:
+	case BPF_FUNC_msg_redirect_map:
+	case BPF_FUNC_sock_map_update:
+		if (map->map_type != BPF_MAP_TYPE_SOCKMAP)
+			goto error;
+		break;
+	case BPF_FUNC_sk_redirect_hash:
+	case BPF_FUNC_msg_redirect_hash:
+	case BPF_FUNC_sock_hash_update:
+		if (map->map_type != BPF_MAP_TYPE_SOCKHASH)
+			goto error;
+		break;
+	case BPF_FUNC_get_local_storage:
+		if (map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
+		    map->map_type != BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
+			goto error;
+		break;
+	case BPF_FUNC_sk_select_reuseport:
+		if (map->map_type != BPF_MAP_TYPE_REUSEPORT_SOCKARRAY &&
+		    map->map_type != BPF_MAP_TYPE_SOCKMAP &&
+		    map->map_type != BPF_MAP_TYPE_SOCKHASH)
+			goto error;
+		break;
+	case BPF_FUNC_map_peek_elem:
+	case BPF_FUNC_map_pop_elem:
+	case BPF_FUNC_map_push_elem:
+		if (map->map_type != BPF_MAP_TYPE_QUEUE &&
+		    map->map_type != BPF_MAP_TYPE_STACK)
+			goto error;
+		break;
+	case BPF_FUNC_sk_storage_get:
+	case BPF_FUNC_sk_storage_delete:
+		if (map->map_type != BPF_MAP_TYPE_SK_STORAGE)
+			goto error;
+		break;
+	case BPF_FUNC_inode_storage_get:
+	case BPF_FUNC_inode_storage_delete:
+		if (map->map_type != BPF_MAP_TYPE_INODE_STORAGE)
+			goto error;
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+error:
+	verbose(env, "cannot pass map_type %d into func %s#%d\n",
+		map->map_type, func_id_name(func_id), func_id);
+	return -EINVAL;
+}
+
+static bool check_raw_mode_ok(const struct bpf_func_proto *fn)
+{
+	int count = 0;
+
+	if (fn->arg1_type == ARG_PTR_TO_UNINIT_MEM)
+		count++;
+	if (fn->arg2_type == ARG_PTR_TO_UNINIT_MEM)
+		count++;
+	if (fn->arg3_type == ARG_PTR_TO_UNINIT_MEM)
+		count++;
+	if (fn->arg4_type == ARG_PTR_TO_UNINIT_MEM)
+		count++;
+	if (fn->arg5_type == ARG_PTR_TO_UNINIT_MEM)
+		count++;
+
+	/* We only support one arg being in raw mode at the moment,
+	 * which is sufficient for the helper functions we have
+	 * right now.
+	 */
+	return count <= 1;
+}
+
+static bool check_args_pair_invalid(enum bpf_arg_type arg_curr,
+				    enum bpf_arg_type arg_next)
+{
+	return (arg_type_is_mem_ptr(arg_curr) &&
+	        !arg_type_is_mem_size(arg_next)) ||
+	       (!arg_type_is_mem_ptr(arg_curr) &&
+		arg_type_is_mem_size(arg_next));
+}
+
+static bool check_arg_pair_ok(const struct bpf_func_proto *fn)
+{
+	/* bpf_xxx(..., buf, len) call will access 'len'
+	 * bytes from memory 'buf'. Both arg types need
+	 * to be paired, so make sure there's no buggy
+	 * helper function specification.
+	 */
+	if (arg_type_is_mem_size(fn->arg1_type) ||
+	    arg_type_is_mem_ptr(fn->arg5_type)  ||
+	    check_args_pair_invalid(fn->arg1_type, fn->arg2_type) ||
+	    check_args_pair_invalid(fn->arg2_type, fn->arg3_type) ||
+	    check_args_pair_invalid(fn->arg3_type, fn->arg4_type) ||
+	    check_args_pair_invalid(fn->arg4_type, fn->arg5_type))
+		return false;
+
+	return true;
+}
+
+static bool check_refcount_ok(const struct bpf_func_proto *fn, int func_id)
+{
+	int count = 0;
+
+	if (arg_type_may_be_refcounted(fn->arg1_type))
+		count++;
+	if (arg_type_may_be_refcounted(fn->arg2_type))
+		count++;
+	if (arg_type_may_be_refcounted(fn->arg3_type))
+		count++;
+	if (arg_type_may_be_refcounted(fn->arg4_type))
+		count++;
+	if (arg_type_may_be_refcounted(fn->arg5_type))
+		count++;
+
+	/* A reference acquiring function cannot acquire
+	 * another refcounted ptr.
+	 */
+	if (may_be_acquire_function(func_id) && count)
+		return false;
+
+	/* We only support one arg being unreferenced at the moment,
+	 * which is sufficient for the helper functions we have right now.
+	 */
+	return count <= 1;
+}
+
+static bool check_btf_id_ok(const struct bpf_func_proto *fn)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(fn->arg_type); i++) {
+		if (fn->arg_type[i] == ARG_PTR_TO_BTF_ID && !fn->arg_btf_id[i])
+			return false;
+
+		if (fn->arg_type[i] != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i])
+			return false;
+	}
+
+	return true;
+}
+
+static int check_func_proto(const struct bpf_func_proto *fn, int func_id)
+{
+	return check_raw_mode_ok(fn) &&
+	       check_arg_pair_ok(fn) &&
+	       check_btf_id_ok(fn) &&
+	       check_refcount_ok(fn, func_id) ? 0 : -EINVAL;
+}
+
+/* Packet data might have moved, any old PTR_TO_PACKET[_META,_END]
+ * are now invalid, so turn them into unknown SCALAR_VALUE.
+ */
+static void clear_all_pkt_pointers(struct bpf_verifier_env *env)
+{
+	struct bpf_func_state *state;
+	struct bpf_reg_state *reg;
+
+	bpf_for_each_reg_in_vstate(env->cur_state, state, reg, ({
+		if (reg_is_pkt_pointer_any(reg))
+			__mark_reg_unknown(env, reg);
+	}));
+}
+
+enum {
+	AT_PKT_END = -1,
+	BEYOND_PKT_END = -2,
+};
+
+static void mark_pkt_end(struct bpf_verifier_state *vstate, int regn, bool range_open)
+{
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	struct bpf_reg_state *reg = &state->regs[regn];
+
+	if (reg->type != PTR_TO_PACKET)
+		/* PTR_TO_PACKET_META is not supported yet */
+		return;
+
+	/* The 'reg' is pkt > pkt_end or pkt >= pkt_end.
+	 * How far beyond pkt_end it goes is unknown.
+	 * if (!range_open) it's the case of pkt >= pkt_end
+	 * if (range_open) it's the case of pkt > pkt_end
+	 * hence this pointer is at least 1 byte bigger than pkt_end
+	 */
+	if (range_open)
+		reg->range = BEYOND_PKT_END;
+	else
+		reg->range = AT_PKT_END;
+}
+
+/* The pointer with the specified id has released its reference to kernel
+ * resources. Identify all copies of the same pointer and clear the reference.
+ */
+static int release_reference(struct bpf_verifier_env *env,
+			     int ref_obj_id)
+{
+	struct bpf_func_state *state;
+	struct bpf_reg_state *reg;
+	int err;
+
+	err = release_reference_state(cur_func(env), ref_obj_id);
+	if (err)
+		return err;
+
+	bpf_for_each_reg_in_vstate(env->cur_state, state, reg, ({
+		if (reg->ref_obj_id == ref_obj_id) {
+			if (!env->allow_ptr_leaks)
+				__mark_reg_not_init(env, reg);
+			else
+				__mark_reg_unknown(env, reg);
+		}
+	}));
+
+	return 0;
+}
+
+static void clear_caller_saved_regs(struct bpf_verifier_env *env,
+				    struct bpf_reg_state *regs)
+{
+	int i;
+
+	/* after the call registers r0 - r5 were scratched */
+	for (i = 0; i < CALLER_SAVED_REGS; i++) {
+		mark_reg_not_init(env, regs, caller_saved[i]);
+		check_reg_arg(env, caller_saved[i], DST_OP_NO_MARK);
+	}
+}
+
+static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
+			   int *insn_idx)
+{
+	struct bpf_verifier_state *state = env->cur_state;
+	struct bpf_func_info_aux *func_info_aux;
+	struct bpf_func_state *caller, *callee;
+	int i, err, subprog, target_insn;
+	bool is_global = false;
+
+	if (state->curframe + 1 >= MAX_CALL_FRAMES) {
+		verbose(env, "the call stack of %d frames is too deep\n",
+			state->curframe + 2);
+		return -E2BIG;
+	}
+
+	target_insn = *insn_idx + insn->imm;
+	subprog = find_subprog(env, target_insn + 1);
+	if (subprog < 0) {
+		verbose(env, "verifier bug. No program starts at insn %d\n",
+			target_insn + 1);
+		return -EFAULT;
+	}
+
+	caller = state->frame[state->curframe];
+	if (state->frame[state->curframe + 1]) {
+		verbose(env, "verifier bug. Frame %d already allocated\n",
+			state->curframe + 1);
+		return -EFAULT;
+	}
+
+	func_info_aux = env->prog->aux->func_info_aux;
+	if (func_info_aux)
+		is_global = func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
+	err = btf_check_func_arg_match(env, subprog, caller->regs);
+	if (err == -EFAULT)
+		return err;
+	if (is_global) {
+		if (err) {
+			verbose(env, "Caller passes invalid args into func#%d\n",
+				subprog);
+			return err;
+		} else {
+			if (env->log.level & BPF_LOG_LEVEL)
+				verbose(env,
+					"Func#%d is global and valid. Skipping.\n",
+					subprog);
+			clear_caller_saved_regs(env, caller->regs);
+
+			/* All global functions return a 64-bit SCALAR_VALUE */
+			mark_reg_unknown(env, caller->regs, BPF_REG_0);
+			caller->regs[BPF_REG_0].subreg_def = DEF_NOT_SUBREG;
+
+			/* continue with next insn after call */
+			return 0;
+		}
+	}
+
+	callee = kzalloc(sizeof(*callee), GFP_KERNEL);
+	if (!callee)
+		return -ENOMEM;
+	state->frame[state->curframe + 1] = callee;
+
+	/* callee cannot access r0, r6 - r9 for reading and has to write
+	 * into its own stack before reading from it.
+	 * callee can read/write into caller's stack
+	 */
+	init_func_state(env, callee,
+			/* remember the callsite, it will be used by bpf_exit */
+			*insn_idx /* callsite */,
+			state->curframe + 1 /* frameno within this callchain */,
+			subprog /* subprog number within this prog */);
+
+	/* Transfer references to the callee */
+	err = transfer_reference_state(callee, caller);
+	if (err)
+		return err;
+
+	/* copy r1 - r5 args that callee can access.  The copy includes parent
+	 * pointers, which connects us up to the liveness chain
+	 */
+	for (i = BPF_REG_1; i <= BPF_REG_5; i++)
+		callee->regs[i] = caller->regs[i];
+
+	clear_caller_saved_regs(env, caller->regs);
+
+	/* only increment it after check_reg_arg() finished */
+	state->curframe++;
+
+	/* and go analyze first insn of the callee */
+	*insn_idx = target_insn;
+
+	if (env->log.level & BPF_LOG_LEVEL) {
+		verbose(env, "caller:\n");
+		print_verifier_state(env, caller);
+		verbose(env, "callee:\n");
+		print_verifier_state(env, callee);
+	}
+	return 0;
+}
+
+static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
+{
+	struct bpf_verifier_state *state = env->cur_state;
+	struct bpf_func_state *caller, *callee;
+	struct bpf_reg_state *r0;
+	int err;
+
+	callee = state->frame[state->curframe];
+	r0 = &callee->regs[BPF_REG_0];
+	if (r0->type == PTR_TO_STACK) {
+		/* technically it's ok to return caller's stack pointer
+		 * (or caller's caller's pointer) back to the caller,
+		 * since these pointers are valid. Only current stack
+		 * pointer will be invalid as soon as function exits,
+		 * but let's be conservative
+		 */
+		verbose(env, "cannot return stack pointer to the caller\n");
+		return -EINVAL;
+	}
+
+	state->curframe--;
+	caller = state->frame[state->curframe];
+	/* return to the caller whatever r0 had in the callee */
+	caller->regs[BPF_REG_0] = *r0;
+
+	/* Transfer references to the caller */
+	err = transfer_reference_state(caller, callee);
+	if (err)
+		return err;
+
+	*insn_idx = callee->callsite + 1;
+	if (env->log.level & BPF_LOG_LEVEL) {
+		verbose(env, "returning from callee:\n");
+		print_verifier_state(env, callee);
+		verbose(env, "to caller at %d:\n", *insn_idx);
+		print_verifier_state(env, caller);
+	}
+	/* clear everything in the callee */
+	free_func_state(callee);
+	state->frame[state->curframe + 1] = NULL;
+	return 0;
+}
+
+static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
+				   int func_id,
+				   struct bpf_call_arg_meta *meta)
+{
+	struct bpf_reg_state *ret_reg = &regs[BPF_REG_0];
+
+	if (ret_type != RET_INTEGER ||
+	    (func_id != BPF_FUNC_get_stack &&
+	     func_id != BPF_FUNC_probe_read_str &&
+	     func_id != BPF_FUNC_probe_read_kernel_str &&
+	     func_id != BPF_FUNC_probe_read_user_str))
+		return;
+
+	ret_reg->smax_value = meta->msize_max_value;
+	ret_reg->s32_max_value = meta->msize_max_value;
+	ret_reg->smin_value = -MAX_ERRNO;
+	ret_reg->s32_min_value = -MAX_ERRNO;
+	reg_bounds_sync(ret_reg);
+}
+
+static int
+record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
+		int func_id, int insn_idx)
+{
+	struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
+	struct bpf_map *map = meta->map_ptr;
+
+	if (func_id != BPF_FUNC_tail_call &&
+	    func_id != BPF_FUNC_map_lookup_elem &&
+	    func_id != BPF_FUNC_map_update_elem &&
+	    func_id != BPF_FUNC_map_delete_elem &&
+	    func_id != BPF_FUNC_map_push_elem &&
+	    func_id != BPF_FUNC_map_pop_elem &&
+	    func_id != BPF_FUNC_map_peek_elem)
+		return 0;
+
+	if (map == NULL) {
+		verbose(env, "kernel subsystem misconfigured verifier\n");
+		return -EINVAL;
+	}
+
+	/* In case of read-only, some additional restrictions
+	 * need to be applied in order to prevent altering the
+	 * state of the map from program side.
+	 */
+	if ((map->map_flags & BPF_F_RDONLY_PROG) &&
+	    (func_id == BPF_FUNC_map_delete_elem ||
+	     func_id == BPF_FUNC_map_update_elem ||
+	     func_id == BPF_FUNC_map_push_elem ||
+	     func_id == BPF_FUNC_map_pop_elem)) {
+		verbose(env, "write into map forbidden\n");
+		return -EACCES;
+	}
+
+	if (!BPF_MAP_PTR(aux->map_ptr_state))
+		bpf_map_ptr_store(aux, meta->map_ptr,
+				  !meta->map_ptr->bypass_spec_v1);
+	else if (BPF_MAP_PTR(aux->map_ptr_state) != meta->map_ptr)
+		bpf_map_ptr_store(aux, BPF_MAP_PTR_POISON,
+				  !meta->map_ptr->bypass_spec_v1);
+	return 0;
+}
+
+static int
+record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
+		int func_id, int insn_idx)
+{
+	struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
+	struct bpf_reg_state *regs = cur_regs(env), *reg;
+	struct bpf_map *map = meta->map_ptr;
+	u64 val, max;
+	int err;
+
+	if (func_id != BPF_FUNC_tail_call)
+		return 0;
+	if (!map || map->map_type != BPF_MAP_TYPE_PROG_ARRAY) {
+		verbose(env, "kernel subsystem misconfigured verifier\n");
+		return -EINVAL;
+	}
+
+	reg = &regs[BPF_REG_3];
+	val = reg->var_off.value;
+	max = map->max_entries;
+
+	if (!(register_is_const(reg) && val < max)) {
+		bpf_map_key_store(aux, BPF_MAP_KEY_POISON);
+		return 0;
+	}
+
+	err = mark_chain_precision(env, BPF_REG_3);
+	if (err)
+		return err;
+	if (bpf_map_key_unseen(aux))
+		bpf_map_key_store(aux, val);
+	else if (!bpf_map_key_poisoned(aux) &&
+		  bpf_map_key_immediate(aux) != val)
+		bpf_map_key_store(aux, BPF_MAP_KEY_POISON);
+	return 0;
+}
+
+static int check_reference_leak(struct bpf_verifier_env *env)
+{
+	struct bpf_func_state *state = cur_func(env);
+	int i;
+
+	for (i = 0; i < state->acquired_refs; i++) {
+		verbose(env, "Unreleased reference id=%d alloc_insn=%d\n",
+			state->refs[i].id, state->refs[i].insn_idx);
+	}
+	return state->acquired_refs ? -EINVAL : 0;
+}
+
+static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
+{
+	const struct bpf_func_proto *fn = NULL;
+	struct bpf_reg_state *regs;
+	struct bpf_call_arg_meta meta;
+	bool changes_data;
+	int i, err;
+
+	/* find function prototype */
+	if (func_id < 0 || func_id >= __BPF_FUNC_MAX_ID) {
+		verbose(env, "invalid func %s#%d\n", func_id_name(func_id),
+			func_id);
+		return -EINVAL;
+	}
+
+	if (env->ops->get_func_proto)
+		fn = env->ops->get_func_proto(func_id, env->prog);
+	if (!fn) {
+		verbose(env, "unknown func %s#%d\n", func_id_name(func_id),
+			func_id);
+		return -EINVAL;
+	}
+
+	/* eBPF programs must be GPL compatible to use GPL-ed functions */
+	if (!env->prog->gpl_compatible && fn->gpl_only) {
+		verbose(env, "cannot call GPL-restricted function from non-GPL compatible program\n");
+		return -EINVAL;
+	}
+
+	if (fn->allowed && !fn->allowed(env->prog)) {
+		verbose(env, "helper call is not allowed in probe\n");
+		return -EINVAL;
+	}
+
+	/* With LD_ABS/IND some JITs save/restore skb from r1. */
+	changes_data = bpf_helper_changes_pkt_data(fn->func);
+	if (changes_data && fn->arg1_type != ARG_PTR_TO_CTX) {
+		verbose(env, "kernel subsystem misconfigured func %s#%d: r1 != ctx\n",
+			func_id_name(func_id), func_id);
+		return -EINVAL;
+	}
+
+	memset(&meta, 0, sizeof(meta));
+	meta.pkt_access = fn->pkt_access;
+
+	err = check_func_proto(fn, func_id);
+	if (err) {
+		verbose(env, "kernel subsystem misconfigured func %s#%d\n",
+			func_id_name(func_id), func_id);
+		return err;
+	}
+
+	meta.func_id = func_id;
+	/* check args */
+	for (i = 0; i < 5; i++) {
+		err = check_func_arg(env, i, &meta, fn);
+		if (err)
+			return err;
+	}
+
+	err = record_func_map(env, &meta, func_id, insn_idx);
+	if (err)
+		return err;
+
+	err = record_func_key(env, &meta, func_id, insn_idx);
+	if (err)
+		return err;
+
+	/* Mark slots with STACK_MISC in case of raw mode, stack offset
+	 * is inferred from register state.
+	 */
+	for (i = 0; i < meta.access_size; i++) {
+		err = check_mem_access(env, insn_idx, meta.regno, i, BPF_B,
+				       BPF_WRITE, -1, false);
+		if (err)
+			return err;
+	}
+
+	if (func_id == BPF_FUNC_tail_call) {
+		err = check_reference_leak(env);
+		if (err) {
+			verbose(env, "tail_call would lead to reference leak\n");
+			return err;
+		}
+	} else if (is_release_function(func_id)) {
+		err = release_reference(env, meta.ref_obj_id);
+		if (err) {
+			verbose(env, "func %s#%d reference has not been acquired before\n",
+				func_id_name(func_id), func_id);
+			return err;
+		}
+	}
+
+	regs = cur_regs(env);
+
+	/* check that flags argument in get_local_storage(map, flags) is 0,
+	 * this is required because get_local_storage() can't return an error.
+	 */
+	if (func_id == BPF_FUNC_get_local_storage &&
+	    !register_is_null(&regs[BPF_REG_2])) {
+		verbose(env, "get_local_storage() doesn't support non-zero flags\n");
+		return -EINVAL;
+	}
+
+	/* reset caller saved regs */
+	for (i = 0; i < CALLER_SAVED_REGS; i++) {
+		mark_reg_not_init(env, regs, caller_saved[i]);
+		check_reg_arg(env, caller_saved[i], DST_OP_NO_MARK);
+	}
+
+	/* helper call returns 64-bit value. */
+	regs[BPF_REG_0].subreg_def = DEF_NOT_SUBREG;
+
+	/* update return register (already marked as written above) */
+	if (fn->ret_type == RET_INTEGER) {
+		/* sets type to SCALAR_VALUE */
+		mark_reg_unknown(env, regs, BPF_REG_0);
+	} else if (fn->ret_type == RET_VOID) {
+		regs[BPF_REG_0].type = NOT_INIT;
+	} else if (fn->ret_type == RET_PTR_TO_MAP_VALUE_OR_NULL ||
+		   fn->ret_type == RET_PTR_TO_MAP_VALUE) {
+		/* There is no offset yet applied, variable or fixed */
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		/* remember map_ptr, so that check_map_access()
+		 * can check 'value_size' boundary of memory access
+		 * to map element returned from bpf_map_lookup_elem()
+		 */
+		if (meta.map_ptr == NULL) {
+			verbose(env,
+				"kernel subsystem misconfigured verifier\n");
+			return -EINVAL;
+		}
+		regs[BPF_REG_0].map_ptr = meta.map_ptr;
+		if (fn->ret_type == RET_PTR_TO_MAP_VALUE) {
+			regs[BPF_REG_0].type = PTR_TO_MAP_VALUE;
+			if (map_value_has_spin_lock(meta.map_ptr))
+				regs[BPF_REG_0].id = ++env->id_gen;
+		} else {
+			regs[BPF_REG_0].type = PTR_TO_MAP_VALUE_OR_NULL;
+		}
+	} else if (fn->ret_type == RET_PTR_TO_SOCKET_OR_NULL) {
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL;
+	} else if (fn->ret_type == RET_PTR_TO_SOCK_COMMON_OR_NULL) {
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].type = PTR_TO_SOCK_COMMON_OR_NULL;
+	} else if (fn->ret_type == RET_PTR_TO_TCP_SOCK_OR_NULL) {
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].type = PTR_TO_TCP_SOCK_OR_NULL;
+	} else if (fn->ret_type == RET_PTR_TO_ALLOC_MEM_OR_NULL) {
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].type = PTR_TO_MEM_OR_NULL;
+		regs[BPF_REG_0].mem_size = meta.mem_size;
+	} else if (fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL ||
+		   fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID) {
+		const struct btf_type *t;
+
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		t = btf_type_skip_modifiers(btf_vmlinux, meta.ret_btf_id, NULL);
+		if (!btf_type_is_struct(t)) {
+			u32 tsize;
+			const struct btf_type *ret;
+			const char *tname;
+
+			/* resolve the type size of ksym. */
+			ret = btf_resolve_size(btf_vmlinux, t, &tsize);
+			if (IS_ERR(ret)) {
+				tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+				verbose(env, "unable to resolve the size of type '%s': %ld\n",
+					tname, PTR_ERR(ret));
+				return -EINVAL;
+			}
+			regs[BPF_REG_0].type =
+				fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
+				PTR_TO_MEM : PTR_TO_MEM_OR_NULL;
+			regs[BPF_REG_0].mem_size = tsize;
+		} else {
+			regs[BPF_REG_0].type =
+				fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
+				PTR_TO_BTF_ID : PTR_TO_BTF_ID_OR_NULL;
+			regs[BPF_REG_0].btf_id = meta.ret_btf_id;
+		}
+	} else if (fn->ret_type == RET_PTR_TO_BTF_ID_OR_NULL) {
+		int ret_btf_id;
+
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].type = PTR_TO_BTF_ID_OR_NULL;
+		ret_btf_id = *fn->ret_btf_id;
+		if (ret_btf_id == 0) {
+			verbose(env, "invalid return type %d of func %s#%d\n",
+				fn->ret_type, func_id_name(func_id), func_id);
+			return -EINVAL;
+		}
+		regs[BPF_REG_0].btf_id = ret_btf_id;
+	} else {
+		verbose(env, "unknown return type %d of func %s#%d\n",
+			fn->ret_type, func_id_name(func_id), func_id);
+		return -EINVAL;
+	}
+
+	if (reg_type_may_be_null(regs[BPF_REG_0].type))
+		regs[BPF_REG_0].id = ++env->id_gen;
+
+	if (is_ptr_cast_function(func_id)) {
+		/* For release_reference() */
+		regs[BPF_REG_0].ref_obj_id = meta.ref_obj_id;
+	} else if (is_acquire_function(func_id, meta.map_ptr)) {
+		int id = acquire_reference_state(env, insn_idx);
+
+		if (id < 0)
+			return id;
+		/* For mark_ptr_or_null_reg() */
+		regs[BPF_REG_0].id = id;
+		/* For release_reference() */
+		regs[BPF_REG_0].ref_obj_id = id;
+	}
+
+	do_refine_retval_range(regs, fn->ret_type, func_id, &meta);
+
+	err = check_map_func_compatibility(env, meta.map_ptr, func_id);
+	if (err)
+		return err;
+
+	if ((func_id == BPF_FUNC_get_stack ||
+	     func_id == BPF_FUNC_get_task_stack) &&
+	    !env->prog->has_callchain_buf) {
+		const char *err_str;
+
+#ifdef CONFIG_PERF_EVENTS
+		err = get_callchain_buffers(sysctl_perf_event_max_stack);
+		err_str = "cannot get callchain buffer for func %s#%d\n";
+#else
+		err = -ENOTSUPP;
+		err_str = "func %s#%d not supported without CONFIG_PERF_EVENTS\n";
+#endif
+		if (err) {
+			verbose(env, err_str, func_id_name(func_id), func_id);
+			return err;
+		}
+
+		env->prog->has_callchain_buf = true;
+	}
+
+	if (func_id == BPF_FUNC_get_stackid || func_id == BPF_FUNC_get_stack)
+		env->prog->call_get_stack = true;
+
+	if (changes_data)
+		clear_all_pkt_pointers(env);
+	return 0;
+}
+
+static bool signed_add_overflows(s64 a, s64 b)
+{
+	/* Do the add in u64, where overflow is well-defined */
+	s64 res = (s64)((u64)a + (u64)b);
+
+	if (b < 0)
+		return res > a;
+	return res < a;
+}
+
+static bool signed_add32_overflows(s32 a, s32 b)
+{
+	/* Do the add in u32, where overflow is well-defined */
+	s32 res = (s32)((u32)a + (u32)b);
+
+	if (b < 0)
+		return res > a;
+	return res < a;
+}
+
+static bool signed_sub_overflows(s64 a, s64 b)
+{
+	/* Do the sub in u64, where overflow is well-defined */
+	s64 res = (s64)((u64)a - (u64)b);
+
+	if (b < 0)
+		return res < a;
+	return res > a;
+}
+
+static bool signed_sub32_overflows(s32 a, s32 b)
+{
+	/* Do the sub in u32, where overflow is well-defined */
+	s32 res = (s32)((u32)a - (u32)b);
+
+	if (b < 0)
+		return res < a;
+	return res > a;
+}
+
+static bool check_reg_sane_offset(struct bpf_verifier_env *env,
+				  const struct bpf_reg_state *reg,
+				  enum bpf_reg_type type)
+{
+	bool known = tnum_is_const(reg->var_off);
+	s64 val = reg->var_off.value;
+	s64 smin = reg->smin_value;
+
+	if (known && (val >= BPF_MAX_VAR_OFF || val <= -BPF_MAX_VAR_OFF)) {
+		verbose(env, "math between %s pointer and %lld is not allowed\n",
+			reg_type_str[type], val);
+		return false;
+	}
+
+	if (reg->off >= BPF_MAX_VAR_OFF || reg->off <= -BPF_MAX_VAR_OFF) {
+		verbose(env, "%s pointer offset %d is not allowed\n",
+			reg_type_str[type], reg->off);
+		return false;
+	}
+
+	if (smin == S64_MIN) {
+		verbose(env, "math between %s pointer and register with unbounded min value is not allowed\n",
+			reg_type_str[type]);
+		return false;
+	}
+
+	if (smin >= BPF_MAX_VAR_OFF || smin <= -BPF_MAX_VAR_OFF) {
+		verbose(env, "value %lld makes %s pointer be out of bounds\n",
+			smin, reg_type_str[type]);
+		return false;
+	}
+
+	return true;
+}
+
+static struct bpf_insn_aux_data *cur_aux(struct bpf_verifier_env *env)
+{
+	return &env->insn_aux_data[env->insn_idx];
+}
+
+enum {
+	REASON_BOUNDS	= -1,
+	REASON_TYPE	= -2,
+	REASON_PATHS	= -3,
+	REASON_LIMIT	= -4,
+	REASON_STACK	= -5,
+};
+
+static int retrieve_ptr_limit(const struct bpf_reg_state *ptr_reg,
+			      u32 *alu_limit, bool mask_to_left)
+{
+	u32 max = 0, ptr_limit = 0;
+
+	switch (ptr_reg->type) {
+	case PTR_TO_STACK:
+		/* Offset 0 is out-of-bounds, but acceptable start for the
+		 * left direction, see BPF_REG_FP. Also, unknown scalar
+		 * offset where we would need to deal with min/max bounds is
+		 * currently prohibited for unprivileged.
+		 */
+		max = MAX_BPF_STACK + mask_to_left;
+		ptr_limit = -(ptr_reg->var_off.value + ptr_reg->off);
+		break;
+	case PTR_TO_MAP_VALUE:
+		max = ptr_reg->map_ptr->value_size;
+		ptr_limit = (mask_to_left ?
+			     ptr_reg->smin_value :
+			     ptr_reg->umax_value) + ptr_reg->off;
+		break;
+	default:
+		return REASON_TYPE;
+	}
+
+	if (ptr_limit >= max)
+		return REASON_LIMIT;
+	*alu_limit = ptr_limit;
+	return 0;
+}
+
+static bool can_skip_alu_sanitation(const struct bpf_verifier_env *env,
+				    const struct bpf_insn *insn)
+{
+	return env->bypass_spec_v1 || BPF_SRC(insn->code) == BPF_K;
+}
+
+static int update_alu_sanitation_state(struct bpf_insn_aux_data *aux,
+				       u32 alu_state, u32 alu_limit)
+{
+	/* If we arrived here from different branches with different
+	 * state or limits to sanitize, then this won't work.
+	 */
+	if (aux->alu_state &&
+	    (aux->alu_state != alu_state ||
+	     aux->alu_limit != alu_limit))
+		return REASON_PATHS;
+
+	/* Corresponding fixup done in fixup_bpf_calls(). */
+	aux->alu_state = alu_state;
+	aux->alu_limit = alu_limit;
+	return 0;
+}
+
+static int sanitize_val_alu(struct bpf_verifier_env *env,
+			    struct bpf_insn *insn)
+{
+	struct bpf_insn_aux_data *aux = cur_aux(env);
+
+	if (can_skip_alu_sanitation(env, insn))
+		return 0;
+
+	return update_alu_sanitation_state(aux, BPF_ALU_NON_POINTER, 0);
+}
+
+static bool sanitize_needed(u8 opcode)
+{
+	return opcode == BPF_ADD || opcode == BPF_SUB;
+}
+
+struct bpf_sanitize_info {
+	struct bpf_insn_aux_data aux;
+	bool mask_to_left;
+};
+
+static struct bpf_verifier_state *
+sanitize_speculative_path(struct bpf_verifier_env *env,
+			  const struct bpf_insn *insn,
+			  u32 next_idx, u32 curr_idx)
+{
+	struct bpf_verifier_state *branch;
+	struct bpf_reg_state *regs;
+
+	branch = push_stack(env, next_idx, curr_idx, true);
+	if (branch && insn) {
+		regs = branch->frame[branch->curframe]->regs;
+		if (BPF_SRC(insn->code) == BPF_K) {
+			mark_reg_unknown(env, regs, insn->dst_reg);
+		} else if (BPF_SRC(insn->code) == BPF_X) {
+			mark_reg_unknown(env, regs, insn->dst_reg);
+			mark_reg_unknown(env, regs, insn->src_reg);
+		}
+	}
+	return branch;
+}
+
+static int sanitize_ptr_alu(struct bpf_verifier_env *env,
+			    struct bpf_insn *insn,
+			    const struct bpf_reg_state *ptr_reg,
+			    const struct bpf_reg_state *off_reg,
+			    struct bpf_reg_state *dst_reg,
+			    struct bpf_sanitize_info *info,
+			    const bool commit_window)
+{
+	struct bpf_insn_aux_data *aux = commit_window ? cur_aux(env) : &info->aux;
+	struct bpf_verifier_state *vstate = env->cur_state;
+	bool off_is_imm = tnum_is_const(off_reg->var_off);
+	bool off_is_neg = off_reg->smin_value < 0;
+	bool ptr_is_dst_reg = ptr_reg == dst_reg;
+	u8 opcode = BPF_OP(insn->code);
+	u32 alu_state, alu_limit;
+	struct bpf_reg_state tmp;
+	bool ret;
+	int err;
+
+	if (can_skip_alu_sanitation(env, insn))
+		return 0;
+
+	/* We already marked aux for masking from non-speculative
+	 * paths, thus we got here in the first place. We only care
+	 * to explore bad access from here.
+	 */
+	if (vstate->speculative)
+		goto do_sim;
+
+	if (!commit_window) {
+		if (!tnum_is_const(off_reg->var_off) &&
+		    (off_reg->smin_value < 0) != (off_reg->smax_value < 0))
+			return REASON_BOUNDS;
+
+		info->mask_to_left = (opcode == BPF_ADD &&  off_is_neg) ||
+				     (opcode == BPF_SUB && !off_is_neg);
+	}
+
+	err = retrieve_ptr_limit(ptr_reg, &alu_limit, info->mask_to_left);
+	if (err < 0)
+		return err;
+
+	if (commit_window) {
+		/* In commit phase we narrow the masking window based on
+		 * the observed pointer move after the simulated operation.
+		 */
+		alu_state = info->aux.alu_state;
+		alu_limit = abs(info->aux.alu_limit - alu_limit);
+	} else {
+		alu_state  = off_is_neg ? BPF_ALU_NEG_VALUE : 0;
+		alu_state |= off_is_imm ? BPF_ALU_IMMEDIATE : 0;
+		alu_state |= ptr_is_dst_reg ?
+			     BPF_ALU_SANITIZE_SRC : BPF_ALU_SANITIZE_DST;
+
+		/* Limit pruning on unknown scalars to enable deep search for
+		 * potential masking differences from other program paths.
+		 */
+		if (!off_is_imm)
+			env->explore_alu_limits = true;
+	}
+
+	err = update_alu_sanitation_state(aux, alu_state, alu_limit);
+	if (err < 0)
+		return err;
+do_sim:
+	/* If we're in commit phase, we're done here given we already
+	 * pushed the truncated dst_reg into the speculative verification
+	 * stack.
+	 *
+	 * Also, when register is a known constant, we rewrite register-based
+	 * operation to immediate-based, and thus do not need masking (and as
+	 * a consequence, do not need to simulate the zero-truncation either).
+	 */
+	if (commit_window || off_is_imm)
+		return 0;
+
+	/* Simulate and find potential out-of-bounds access under
+	 * speculative execution from truncation as a result of
+	 * masking when off was not within expected range. If off
+	 * sits in dst, then we temporarily need to move ptr there
+	 * to simulate dst (== 0) +/-= ptr. Needed, for example,
+	 * for cases where we use K-based arithmetic in one direction
+	 * and truncated reg-based in the other in order to explore
+	 * bad access.
+	 */
+	if (!ptr_is_dst_reg) {
+		tmp = *dst_reg;
+		copy_register_state(dst_reg, ptr_reg);
+	}
+	ret = sanitize_speculative_path(env, NULL, env->insn_idx + 1,
+					env->insn_idx);
+	if (!ptr_is_dst_reg && ret)
+		*dst_reg = tmp;
+	return !ret ? REASON_STACK : 0;
+}
+
+static void sanitize_mark_insn_seen(struct bpf_verifier_env *env)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+
+	/* If we simulate paths under speculation, we don't update the
+	 * insn as 'seen' such that when we verify unreachable paths in
+	 * the non-speculative domain, sanitize_dead_code() can still
+	 * rewrite/sanitize them.
+	 */
+	if (!vstate->speculative)
+		env->insn_aux_data[env->insn_idx].seen = env->pass_cnt;
+}
+
+static int sanitize_err(struct bpf_verifier_env *env,
+			const struct bpf_insn *insn, int reason,
+			const struct bpf_reg_state *off_reg,
+			const struct bpf_reg_state *dst_reg)
+{
+	static const char *err = "pointer arithmetic with it prohibited for !root";
+	const char *op = BPF_OP(insn->code) == BPF_ADD ? "add" : "sub";
+	u32 dst = insn->dst_reg, src = insn->src_reg;
+
+	switch (reason) {
+	case REASON_BOUNDS:
+		verbose(env, "R%d has unknown scalar with mixed signed bounds, %s\n",
+			off_reg == dst_reg ? dst : src, err);
+		break;
+	case REASON_TYPE:
+		verbose(env, "R%d has pointer with unsupported alu operation, %s\n",
+			off_reg == dst_reg ? src : dst, err);
+		break;
+	case REASON_PATHS:
+		verbose(env, "R%d tried to %s from different maps, paths or scalars, %s\n",
+			dst, op, err);
+		break;
+	case REASON_LIMIT:
+		verbose(env, "R%d tried to %s beyond pointer bounds, %s\n",
+			dst, op, err);
+		break;
+	case REASON_STACK:
+		verbose(env, "R%d could not be pushed for speculative verification, %s\n",
+			dst, err);
+		break;
+	default:
+		verbose(env, "verifier internal error: unknown reason (%d)\n",
+			reason);
+		break;
+	}
+
+	return -EACCES;
+}
+
+/* check that stack access falls within stack limits and that 'reg' doesn't
+ * have a variable offset.
+ *
+ * Variable offset is prohibited for unprivileged mode for simplicity since it
+ * requires corresponding support in Spectre masking for stack ALU.  See also
+ * retrieve_ptr_limit().
+ *
+ *
+ * 'off' includes 'reg->off'.
+ */
+static int check_stack_access_for_ptr_arithmetic(
+				struct bpf_verifier_env *env,
+				int regno,
+				const struct bpf_reg_state *reg,
+				int off)
+{
+	if (!tnum_is_const(reg->var_off)) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env, "R%d variable stack access prohibited for !root, var_off=%s off=%d\n",
+			regno, tn_buf, off);
+		return -EACCES;
+	}
+
+	if (off >= 0 || off < -MAX_BPF_STACK) {
+		verbose(env, "R%d stack pointer arithmetic goes out of range, "
+			"prohibited for !root; off=%d\n", regno, off);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
+static int sanitize_check_bounds(struct bpf_verifier_env *env,
+				 const struct bpf_insn *insn,
+				 const struct bpf_reg_state *dst_reg)
+{
+	u32 dst = insn->dst_reg;
+
+	/* For unprivileged we require that resulting offset must be in bounds
+	 * in order to be able to sanitize access later on.
+	 */
+	if (env->bypass_spec_v1)
+		return 0;
+
+	switch (dst_reg->type) {
+	case PTR_TO_STACK:
+		if (check_stack_access_for_ptr_arithmetic(env, dst, dst_reg,
+					dst_reg->off + dst_reg->var_off.value))
+			return -EACCES;
+		break;
+	case PTR_TO_MAP_VALUE:
+		if (check_map_access(env, dst, dst_reg->off, 1, false)) {
+			verbose(env, "R%d pointer arithmetic of map value goes out of range, "
+				"prohibited for !root\n", dst);
+			return -EACCES;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+/* Handles arithmetic on a pointer and a scalar: computes new min/max and var_off.
+ * Caller should also handle BPF_MOV case separately.
+ * If we return -EACCES, caller may want to try again treating pointer as a
+ * scalar.  So we only emit a diagnostic if !env->allow_ptr_leaks.
+ */
+static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
+				   struct bpf_insn *insn,
+				   const struct bpf_reg_state *ptr_reg,
+				   const struct bpf_reg_state *off_reg)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	struct bpf_reg_state *regs = state->regs, *dst_reg;
+	bool known = tnum_is_const(off_reg->var_off);
+	s64 smin_val = off_reg->smin_value, smax_val = off_reg->smax_value,
+	    smin_ptr = ptr_reg->smin_value, smax_ptr = ptr_reg->smax_value;
+	u64 umin_val = off_reg->umin_value, umax_val = off_reg->umax_value,
+	    umin_ptr = ptr_reg->umin_value, umax_ptr = ptr_reg->umax_value;
+	struct bpf_sanitize_info info = {};
+	u8 opcode = BPF_OP(insn->code);
+	u32 dst = insn->dst_reg;
+	int ret;
+
+	dst_reg = &regs[dst];
+
+	if ((known && (smin_val != smax_val || umin_val != umax_val)) ||
+	    smin_val > smax_val || umin_val > umax_val) {
+		/* Taint dst register if offset had invalid bounds derived from
+		 * e.g. dead branches.
+		 */
+		__mark_reg_unknown(env, dst_reg);
+		return 0;
+	}
+
+	if (BPF_CLASS(insn->code) != BPF_ALU64) {
+		/* 32-bit ALU ops on pointers produce (meaningless) scalars */
+		if (opcode == BPF_SUB && env->allow_ptr_leaks) {
+			__mark_reg_unknown(env, dst_reg);
+			return 0;
+		}
+
+		verbose(env,
+			"R%d 32-bit pointer arithmetic prohibited\n",
+			dst);
+		return -EACCES;
+	}
+
+	switch (ptr_reg->type) {
+	case PTR_TO_MAP_VALUE_OR_NULL:
+		verbose(env, "R%d pointer arithmetic on %s prohibited, null-check it first\n",
+			dst, reg_type_str[ptr_reg->type]);
+		return -EACCES;
+	case CONST_PTR_TO_MAP:
+		/* smin_val represents the known value */
+		if (known && smin_val == 0 && opcode == BPF_ADD)
+			break;
+		fallthrough;
+	case PTR_TO_PACKET_END:
+	case PTR_TO_SOCKET:
+	case PTR_TO_SOCK_COMMON:
+	case PTR_TO_TCP_SOCK:
+	case PTR_TO_XDP_SOCK:
+reject:
+		verbose(env, "R%d pointer arithmetic on %s prohibited\n",
+			dst, reg_type_str[ptr_reg->type]);
+		return -EACCES;
+	default:
+		if (reg_type_may_be_null(ptr_reg->type))
+			goto reject;
+		break;
+	}
+
+	/* In case of 'scalar += pointer', dst_reg inherits pointer type and id.
+	 * The id may be overwritten later if we create a new variable offset.
+	 */
+	dst_reg->type = ptr_reg->type;
+	dst_reg->id = ptr_reg->id;
+
+	if (!check_reg_sane_offset(env, off_reg, ptr_reg->type) ||
+	    !check_reg_sane_offset(env, ptr_reg, ptr_reg->type))
+		return -EINVAL;
+
+	/* pointer types do not carry 32-bit bounds at the moment. */
+	__mark_reg32_unbounded(dst_reg);
+
+	if (sanitize_needed(opcode)) {
+		ret = sanitize_ptr_alu(env, insn, ptr_reg, off_reg, dst_reg,
+				       &info, false);
+		if (ret < 0)
+			return sanitize_err(env, insn, ret, off_reg, dst_reg);
+	}
+
+	switch (opcode) {
+	case BPF_ADD:
+		/* We can take a fixed offset as long as it doesn't overflow
+		 * the s32 'off' field
+		 */
+		if (known && (ptr_reg->off + smin_val ==
+			      (s64)(s32)(ptr_reg->off + smin_val))) {
+			/* pointer += K.  Accumulate it into fixed offset */
+			dst_reg->smin_value = smin_ptr;
+			dst_reg->smax_value = smax_ptr;
+			dst_reg->umin_value = umin_ptr;
+			dst_reg->umax_value = umax_ptr;
+			dst_reg->var_off = ptr_reg->var_off;
+			dst_reg->off = ptr_reg->off + smin_val;
+			dst_reg->raw = ptr_reg->raw;
+			break;
+		}
+		/* A new variable offset is created.  Note that off_reg->off
+		 * == 0, since it's a scalar.
+		 * dst_reg gets the pointer type and since some positive
+		 * integer value was added to the pointer, give it a new 'id'
+		 * if it's a PTR_TO_PACKET.
+		 * this creates a new 'base' pointer, off_reg (variable) gets
+		 * added into the variable offset, and we copy the fixed offset
+		 * from ptr_reg.
+		 */
+		if (signed_add_overflows(smin_ptr, smin_val) ||
+		    signed_add_overflows(smax_ptr, smax_val)) {
+			dst_reg->smin_value = S64_MIN;
+			dst_reg->smax_value = S64_MAX;
+		} else {
+			dst_reg->smin_value = smin_ptr + smin_val;
+			dst_reg->smax_value = smax_ptr + smax_val;
+		}
+		if (umin_ptr + umin_val < umin_ptr ||
+		    umax_ptr + umax_val < umax_ptr) {
+			dst_reg->umin_value = 0;
+			dst_reg->umax_value = U64_MAX;
+		} else {
+			dst_reg->umin_value = umin_ptr + umin_val;
+			dst_reg->umax_value = umax_ptr + umax_val;
+		}
+		dst_reg->var_off = tnum_add(ptr_reg->var_off, off_reg->var_off);
+		dst_reg->off = ptr_reg->off;
+		dst_reg->raw = ptr_reg->raw;
+		if (reg_is_pkt_pointer(ptr_reg)) {
+			dst_reg->id = ++env->id_gen;
+			/* something was added to pkt_ptr, set range to zero */
+			dst_reg->raw = 0;
+		}
+		break;
+	case BPF_SUB:
+		if (dst_reg == off_reg) {
+			/* scalar -= pointer.  Creates an unknown scalar */
+			verbose(env, "R%d tried to subtract pointer from scalar\n",
+				dst);
+			return -EACCES;
+		}
+		/* We don't allow subtraction from FP, because (according to
+		 * test_verifier.c test "invalid fp arithmetic", JITs might not
+		 * be able to deal with it.
+		 */
+		if (ptr_reg->type == PTR_TO_STACK) {
+			verbose(env, "R%d subtraction from stack pointer prohibited\n",
+				dst);
+			return -EACCES;
+		}
+		if (known && (ptr_reg->off - smin_val ==
+			      (s64)(s32)(ptr_reg->off - smin_val))) {
+			/* pointer -= K.  Subtract it from fixed offset */
+			dst_reg->smin_value = smin_ptr;
+			dst_reg->smax_value = smax_ptr;
+			dst_reg->umin_value = umin_ptr;
+			dst_reg->umax_value = umax_ptr;
+			dst_reg->var_off = ptr_reg->var_off;
+			dst_reg->id = ptr_reg->id;
+			dst_reg->off = ptr_reg->off - smin_val;
+			dst_reg->raw = ptr_reg->raw;
+			break;
+		}
+		/* A new variable offset is created.  If the subtrahend is known
+		 * nonnegative, then any reg->range we had before is still good.
+		 */
+		if (signed_sub_overflows(smin_ptr, smax_val) ||
+		    signed_sub_overflows(smax_ptr, smin_val)) {
+			/* Overflow possible, we know nothing */
+			dst_reg->smin_value = S64_MIN;
+			dst_reg->smax_value = S64_MAX;
+		} else {
+			dst_reg->smin_value = smin_ptr - smax_val;
+			dst_reg->smax_value = smax_ptr - smin_val;
+		}
+		if (umin_ptr < umax_val) {
+			/* Overflow possible, we know nothing */
+			dst_reg->umin_value = 0;
+			dst_reg->umax_value = U64_MAX;
+		} else {
+			/* Cannot overflow (as long as bounds are consistent) */
+			dst_reg->umin_value = umin_ptr - umax_val;
+			dst_reg->umax_value = umax_ptr - umin_val;
+		}
+		dst_reg->var_off = tnum_sub(ptr_reg->var_off, off_reg->var_off);
+		dst_reg->off = ptr_reg->off;
+		dst_reg->raw = ptr_reg->raw;
+		if (reg_is_pkt_pointer(ptr_reg)) {
+			dst_reg->id = ++env->id_gen;
+			/* something was added to pkt_ptr, set range to zero */
+			if (smin_val < 0)
+				dst_reg->raw = 0;
+		}
+		break;
+	case BPF_AND:
+	case BPF_OR:
+	case BPF_XOR:
+		/* bitwise ops on pointers are troublesome, prohibit. */
+		verbose(env, "R%d bitwise operator %s on pointer prohibited\n",
+			dst, bpf_alu_string[opcode >> 4]);
+		return -EACCES;
+	default:
+		/* other operators (e.g. MUL,LSH) produce non-pointer results */
+		verbose(env, "R%d pointer arithmetic with %s operator prohibited\n",
+			dst, bpf_alu_string[opcode >> 4]);
+		return -EACCES;
+	}
+
+	if (!check_reg_sane_offset(env, dst_reg, ptr_reg->type))
+		return -EINVAL;
+	reg_bounds_sync(dst_reg);
+	if (sanitize_check_bounds(env, insn, dst_reg) < 0)
+		return -EACCES;
+	if (sanitize_needed(opcode)) {
+		ret = sanitize_ptr_alu(env, insn, dst_reg, off_reg, dst_reg,
+				       &info, true);
+		if (ret < 0)
+			return sanitize_err(env, insn, ret, off_reg, dst_reg);
+	}
+
+	return 0;
+}
+
+static void scalar32_min_max_add(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	s32 smin_val = src_reg->s32_min_value;
+	s32 smax_val = src_reg->s32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (signed_add32_overflows(dst_reg->s32_min_value, smin_val) ||
+	    signed_add32_overflows(dst_reg->s32_max_value, smax_val)) {
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		dst_reg->s32_min_value += smin_val;
+		dst_reg->s32_max_value += smax_val;
+	}
+	if (dst_reg->u32_min_value + umin_val < umin_val ||
+	    dst_reg->u32_max_value + umax_val < umax_val) {
+		dst_reg->u32_min_value = 0;
+		dst_reg->u32_max_value = U32_MAX;
+	} else {
+		dst_reg->u32_min_value += umin_val;
+		dst_reg->u32_max_value += umax_val;
+	}
+}
+
+static void scalar_min_max_add(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	s64 smin_val = src_reg->smin_value;
+	s64 smax_val = src_reg->smax_value;
+	u64 umin_val = src_reg->umin_value;
+	u64 umax_val = src_reg->umax_value;
+
+	if (signed_add_overflows(dst_reg->smin_value, smin_val) ||
+	    signed_add_overflows(dst_reg->smax_value, smax_val)) {
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		dst_reg->smin_value += smin_val;
+		dst_reg->smax_value += smax_val;
+	}
+	if (dst_reg->umin_value + umin_val < umin_val ||
+	    dst_reg->umax_value + umax_val < umax_val) {
+		dst_reg->umin_value = 0;
+		dst_reg->umax_value = U64_MAX;
+	} else {
+		dst_reg->umin_value += umin_val;
+		dst_reg->umax_value += umax_val;
+	}
+}
+
+static void scalar32_min_max_sub(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	s32 smin_val = src_reg->s32_min_value;
+	s32 smax_val = src_reg->s32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (signed_sub32_overflows(dst_reg->s32_min_value, smax_val) ||
+	    signed_sub32_overflows(dst_reg->s32_max_value, smin_val)) {
+		/* Overflow possible, we know nothing */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		dst_reg->s32_min_value -= smax_val;
+		dst_reg->s32_max_value -= smin_val;
+	}
+	if (dst_reg->u32_min_value < umax_val) {
+		/* Overflow possible, we know nothing */
+		dst_reg->u32_min_value = 0;
+		dst_reg->u32_max_value = U32_MAX;
+	} else {
+		/* Cannot overflow (as long as bounds are consistent) */
+		dst_reg->u32_min_value -= umax_val;
+		dst_reg->u32_max_value -= umin_val;
+	}
+}
+
+static void scalar_min_max_sub(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	s64 smin_val = src_reg->smin_value;
+	s64 smax_val = src_reg->smax_value;
+	u64 umin_val = src_reg->umin_value;
+	u64 umax_val = src_reg->umax_value;
+
+	if (signed_sub_overflows(dst_reg->smin_value, smax_val) ||
+	    signed_sub_overflows(dst_reg->smax_value, smin_val)) {
+		/* Overflow possible, we know nothing */
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		dst_reg->smin_value -= smax_val;
+		dst_reg->smax_value -= smin_val;
+	}
+	if (dst_reg->umin_value < umax_val) {
+		/* Overflow possible, we know nothing */
+		dst_reg->umin_value = 0;
+		dst_reg->umax_value = U64_MAX;
+	} else {
+		/* Cannot overflow (as long as bounds are consistent) */
+		dst_reg->umin_value -= umax_val;
+		dst_reg->umax_value -= umin_val;
+	}
+}
+
+static void scalar32_min_max_mul(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	s32 smin_val = src_reg->s32_min_value;
+	u32 umin_val = src_reg->u32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (smin_val < 0 || dst_reg->s32_min_value < 0) {
+		/* Ain't nobody got time to multiply that sign */
+		__mark_reg32_unbounded(dst_reg);
+		return;
+	}
+	/* Both values are positive, so we can work with unsigned and
+	 * copy the result to signed (unless it exceeds S32_MAX).
+	 */
+	if (umax_val > U16_MAX || dst_reg->u32_max_value > U16_MAX) {
+		/* Potential overflow, we know nothing */
+		__mark_reg32_unbounded(dst_reg);
+		return;
+	}
+	dst_reg->u32_min_value *= umin_val;
+	dst_reg->u32_max_value *= umax_val;
+	if (dst_reg->u32_max_value > S32_MAX) {
+		/* Overflow possible, we know nothing */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	}
+}
+
+static void scalar_min_max_mul(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	s64 smin_val = src_reg->smin_value;
+	u64 umin_val = src_reg->umin_value;
+	u64 umax_val = src_reg->umax_value;
+
+	if (smin_val < 0 || dst_reg->smin_value < 0) {
+		/* Ain't nobody got time to multiply that sign */
+		__mark_reg64_unbounded(dst_reg);
+		return;
+	}
+	/* Both values are positive, so we can work with unsigned and
+	 * copy the result to signed (unless it exceeds S64_MAX).
+	 */
+	if (umax_val > U32_MAX || dst_reg->umax_value > U32_MAX) {
+		/* Potential overflow, we know nothing */
+		__mark_reg64_unbounded(dst_reg);
+		return;
+	}
+	dst_reg->umin_value *= umin_val;
+	dst_reg->umax_value *= umax_val;
+	if (dst_reg->umax_value > S64_MAX) {
+		/* Overflow possible, we know nothing */
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		dst_reg->smin_value = dst_reg->umin_value;
+		dst_reg->smax_value = dst_reg->umax_value;
+	}
+}
+
+static void scalar32_min_max_and(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_subreg_is_const(src_reg->var_off);
+	bool dst_known = tnum_subreg_is_const(dst_reg->var_off);
+	struct tnum var32_off = tnum_subreg(dst_reg->var_off);
+	s32 smin_val = src_reg->s32_min_value;
+	u32 umax_val = src_reg->u32_max_value;
+
+	if (src_known && dst_known) {
+		__mark_reg32_known(dst_reg, var32_off.value);
+		return;
+	}
+
+	/* We get our minimum from the var_off, since that's inherently
+	 * bitwise.  Our maximum is the minimum of the operands' maxima.
+	 */
+	dst_reg->u32_min_value = var32_off.value;
+	dst_reg->u32_max_value = min(dst_reg->u32_max_value, umax_val);
+	if (dst_reg->s32_min_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ANDing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		/* ANDing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	}
+}
+
+static void scalar_min_max_and(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_is_const(src_reg->var_off);
+	bool dst_known = tnum_is_const(dst_reg->var_off);
+	s64 smin_val = src_reg->smin_value;
+	u64 umax_val = src_reg->umax_value;
+
+	if (src_known && dst_known) {
+		__mark_reg_known(dst_reg, dst_reg->var_off.value);
+		return;
+	}
+
+	/* We get our minimum from the var_off, since that's inherently
+	 * bitwise.  Our maximum is the minimum of the operands' maxima.
+	 */
+	dst_reg->umin_value = dst_reg->var_off.value;
+	dst_reg->umax_value = min(dst_reg->umax_value, umax_val);
+	if (dst_reg->smin_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ANDing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		/* ANDing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->smin_value = dst_reg->umin_value;
+		dst_reg->smax_value = dst_reg->umax_value;
+	}
+	/* We may learn something more from the var_off */
+	__update_reg_bounds(dst_reg);
+}
+
+static void scalar32_min_max_or(struct bpf_reg_state *dst_reg,
+				struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_subreg_is_const(src_reg->var_off);
+	bool dst_known = tnum_subreg_is_const(dst_reg->var_off);
+	struct tnum var32_off = tnum_subreg(dst_reg->var_off);
+	s32 smin_val = src_reg->s32_min_value;
+	u32 umin_val = src_reg->u32_min_value;
+
+	if (src_known && dst_known) {
+		__mark_reg32_known(dst_reg, var32_off.value);
+		return;
+	}
+
+	/* We get our maximum from the var_off, and our minimum is the
+	 * maximum of the operands' minima
+	 */
+	dst_reg->u32_min_value = max(dst_reg->u32_min_value, umin_val);
+	dst_reg->u32_max_value = var32_off.value | var32_off.mask;
+	if (dst_reg->s32_min_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ORing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	} else {
+		/* ORing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	}
+}
+
+static void scalar_min_max_or(struct bpf_reg_state *dst_reg,
+			      struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_is_const(src_reg->var_off);
+	bool dst_known = tnum_is_const(dst_reg->var_off);
+	s64 smin_val = src_reg->smin_value;
+	u64 umin_val = src_reg->umin_value;
+
+	if (src_known && dst_known) {
+		__mark_reg_known(dst_reg, dst_reg->var_off.value);
+		return;
+	}
+
+	/* We get our maximum from the var_off, and our minimum is the
+	 * maximum of the operands' minima
+	 */
+	dst_reg->umin_value = max(dst_reg->umin_value, umin_val);
+	dst_reg->umax_value = dst_reg->var_off.value | dst_reg->var_off.mask;
+	if (dst_reg->smin_value < 0 || smin_val < 0) {
+		/* Lose signed bounds when ORing negative numbers,
+		 * ain't nobody got time for that.
+		 */
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	} else {
+		/* ORing two positives gives a positive, so safe to
+		 * cast result into s64.
+		 */
+		dst_reg->smin_value = dst_reg->umin_value;
+		dst_reg->smax_value = dst_reg->umax_value;
+	}
+	/* We may learn something more from the var_off */
+	__update_reg_bounds(dst_reg);
+}
+
+static void scalar32_min_max_xor(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_subreg_is_const(src_reg->var_off);
+	bool dst_known = tnum_subreg_is_const(dst_reg->var_off);
+	struct tnum var32_off = tnum_subreg(dst_reg->var_off);
+	s32 smin_val = src_reg->s32_min_value;
+
+	if (src_known && dst_known) {
+		__mark_reg32_known(dst_reg, var32_off.value);
+		return;
+	}
+
+	/* We get both minimum and maximum from the var32_off. */
+	dst_reg->u32_min_value = var32_off.value;
+	dst_reg->u32_max_value = var32_off.value | var32_off.mask;
+
+	if (dst_reg->s32_min_value >= 0 && smin_val >= 0) {
+		/* XORing two positive sign numbers gives a positive,
+		 * so safe to cast u32 result into s32.
+		 */
+		dst_reg->s32_min_value = dst_reg->u32_min_value;
+		dst_reg->s32_max_value = dst_reg->u32_max_value;
+	} else {
+		dst_reg->s32_min_value = S32_MIN;
+		dst_reg->s32_max_value = S32_MAX;
+	}
+}
+
+static void scalar_min_max_xor(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	bool src_known = tnum_is_const(src_reg->var_off);
+	bool dst_known = tnum_is_const(dst_reg->var_off);
+	s64 smin_val = src_reg->smin_value;
+
+	if (src_known && dst_known) {
+		/* dst_reg->var_off.value has been updated earlier */
+		__mark_reg_known(dst_reg, dst_reg->var_off.value);
+		return;
+	}
+
+	/* We get both minimum and maximum from the var_off. */
+	dst_reg->umin_value = dst_reg->var_off.value;
+	dst_reg->umax_value = dst_reg->var_off.value | dst_reg->var_off.mask;
+
+	if (dst_reg->smin_value >= 0 && smin_val >= 0) {
+		/* XORing two positive sign numbers gives a positive,
+		 * so safe to cast u64 result into s64.
+		 */
+		dst_reg->smin_value = dst_reg->umin_value;
+		dst_reg->smax_value = dst_reg->umax_value;
+	} else {
+		dst_reg->smin_value = S64_MIN;
+		dst_reg->smax_value = S64_MAX;
+	}
+
+	__update_reg_bounds(dst_reg);
+}
+
+static void __scalar32_min_max_lsh(struct bpf_reg_state *dst_reg,
+				   u64 umin_val, u64 umax_val)
+{
+	/* We lose all sign bit information (except what we can pick
+	 * up from var_off)
+	 */
+	dst_reg->s32_min_value = S32_MIN;
+	dst_reg->s32_max_value = S32_MAX;
+	/* If we might shift our top bit out, then we know nothing */
+	if (umax_val > 31 || dst_reg->u32_max_value > 1ULL << (31 - umax_val)) {
+		dst_reg->u32_min_value = 0;
+		dst_reg->u32_max_value = U32_MAX;
+	} else {
+		dst_reg->u32_min_value <<= umin_val;
+		dst_reg->u32_max_value <<= umax_val;
+	}
+}
+
+static void scalar32_min_max_lsh(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	u32 umax_val = src_reg->u32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+	/* u32 alu operation will zext upper bits */
+	struct tnum subreg = tnum_subreg(dst_reg->var_off);
+
+	__scalar32_min_max_lsh(dst_reg, umin_val, umax_val);
+	dst_reg->var_off = tnum_subreg(tnum_lshift(subreg, umin_val));
+	/* Not required but being careful mark reg64 bounds as unknown so
+	 * that we are forced to pick them up from tnum and zext later and
+	 * if some path skips this step we are still safe.
+	 */
+	__mark_reg64_unbounded(dst_reg);
+	__update_reg32_bounds(dst_reg);
+}
+
+static void __scalar64_min_max_lsh(struct bpf_reg_state *dst_reg,
+				   u64 umin_val, u64 umax_val)
+{
+	/* Special case <<32 because it is a common compiler pattern to sign
+	 * extend subreg by doing <<32 s>>32. In this case if 32bit bounds are
+	 * positive we know this shift will also be positive so we can track
+	 * bounds correctly. Otherwise we lose all sign bit information except
+	 * what we can pick up from var_off. Perhaps we can generalize this
+	 * later to shifts of any length.
+	 */
+	if (umin_val == 32 && umax_val == 32 && dst_reg->s32_max_value >= 0)
+		dst_reg->smax_value = (s64)dst_reg->s32_max_value << 32;
+	else
+		dst_reg->smax_value = S64_MAX;
+
+	if (umin_val == 32 && umax_val == 32 && dst_reg->s32_min_value >= 0)
+		dst_reg->smin_value = (s64)dst_reg->s32_min_value << 32;
+	else
+		dst_reg->smin_value = S64_MIN;
+
+	/* If we might shift our top bit out, then we know nothing */
+	if (dst_reg->umax_value > 1ULL << (63 - umax_val)) {
+		dst_reg->umin_value = 0;
+		dst_reg->umax_value = U64_MAX;
+	} else {
+		dst_reg->umin_value <<= umin_val;
+		dst_reg->umax_value <<= umax_val;
+	}
+}
+
+static void scalar_min_max_lsh(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	u64 umax_val = src_reg->umax_value;
+	u64 umin_val = src_reg->umin_value;
+
+	/* scalar64 calc uses 32bit unshifted bounds so must be called first */
+	__scalar64_min_max_lsh(dst_reg, umin_val, umax_val);
+	__scalar32_min_max_lsh(dst_reg, umin_val, umax_val);
+
+	dst_reg->var_off = tnum_lshift(dst_reg->var_off, umin_val);
+	/* We may learn something more from the var_off */
+	__update_reg_bounds(dst_reg);
+}
+
+static void scalar32_min_max_rsh(struct bpf_reg_state *dst_reg,
+				 struct bpf_reg_state *src_reg)
+{
+	struct tnum subreg = tnum_subreg(dst_reg->var_off);
+	u32 umax_val = src_reg->u32_max_value;
+	u32 umin_val = src_reg->u32_min_value;
+
+	/* BPF_RSH is an unsigned shift.  If the value in dst_reg might
+	 * be negative, then either:
+	 * 1) src_reg might be zero, so the sign bit of the result is
+	 *    unknown, so we lose our signed bounds
+	 * 2) it's known negative, thus the unsigned bounds capture the
+	 *    signed bounds
+	 * 3) the signed bounds cross zero, so they tell us nothing
+	 *    about the result
+	 * If the value in dst_reg is known nonnegative, then again the
+	 * unsigned bounts capture the signed bounds.
+	 * Thus, in all cases it suffices to blow away our signed bounds
+	 * and rely on inferring new ones from the unsigned bounds and
+	 * var_off of the result.
+	 */
+	dst_reg->s32_min_value = S32_MIN;
+	dst_reg->s32_max_value = S32_MAX;
+
+	dst_reg->var_off = tnum_rshift(subreg, umin_val);
+	dst_reg->u32_min_value >>= umax_val;
+	dst_reg->u32_max_value >>= umin_val;
+
+	__mark_reg64_unbounded(dst_reg);
+	__update_reg32_bounds(dst_reg);
+}
+
+static void scalar_min_max_rsh(struct bpf_reg_state *dst_reg,
+			       struct bpf_reg_state *src_reg)
+{
+	u64 umax_val = src_reg->umax_value;
+	u64 umin_val = src_reg->umin_value;
+
+	/* BPF_RSH is an unsigned shift.  If the value in dst_reg might
+	 * be negative, then either:
+	 * 1) src_reg might be zero, so the sign bit of the result is
+	 *    unknown, so we lose our signed bounds
+	 * 2) it's known negative, thus the unsigned bounds capture the
+	 *    signed bounds
+	 * 3) the signed bounds cross zero, so they tell us nothing
+	 *    about the result
+	 * If the value in dst_reg is known nonnegative, then again the
+	 * unsigned bounts capture the signed bounds.
+	 * Thus, in all cases it suffices to blow away our signed bounds
+	 * and rely on inferring new ones from the unsigned bounds and
+	 * var_off of the result.
+	 */
+	dst_reg->smin_value = S64_MIN;
+	dst_reg->smax_value = S64_MAX;
+	dst_reg->var_off = tnum_rshift(dst_reg->var_off, umin_val);
+	dst_reg->umin_value >>= umax_val;
+	dst_reg->umax_value >>= umin_val;
+
+	/* Its not easy to operate on alu32 bounds here because it depends
+	 * on bits being shifted in. Take easy way out and mark unbounded
+	 * so we can recalculate later from tnum.
+	 */
+	__mark_reg32_unbounded(dst_reg);
+	__update_reg_bounds(dst_reg);
+}
+
+static void scalar32_min_max_arsh(struct bpf_reg_state *dst_reg,
+				  struct bpf_reg_state *src_reg)
+{
+	u64 umin_val = src_reg->u32_min_value;
+
+	/* Upon reaching here, src_known is true and
+	 * umax_val is equal to umin_val.
+	 */
+	dst_reg->s32_min_value = (u32)(((s32)dst_reg->s32_min_value) >> umin_val);
+	dst_reg->s32_max_value = (u32)(((s32)dst_reg->s32_max_value) >> umin_val);
+
+	dst_reg->var_off = tnum_arshift(tnum_subreg(dst_reg->var_off), umin_val, 32);
+
+	/* blow away the dst_reg umin_value/umax_value and rely on
+	 * dst_reg var_off to refine the result.
+	 */
+	dst_reg->u32_min_value = 0;
+	dst_reg->u32_max_value = U32_MAX;
+
+	__mark_reg64_unbounded(dst_reg);
+	__update_reg32_bounds(dst_reg);
+}
+
+static void scalar_min_max_arsh(struct bpf_reg_state *dst_reg,
+				struct bpf_reg_state *src_reg)
+{
+	u64 umin_val = src_reg->umin_value;
+
+	/* Upon reaching here, src_known is true and umax_val is equal
+	 * to umin_val.
+	 */
+	dst_reg->smin_value >>= umin_val;
+	dst_reg->smax_value >>= umin_val;
+
+	dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val, 64);
+
+	/* blow away the dst_reg umin_value/umax_value and rely on
+	 * dst_reg var_off to refine the result.
+	 */
+	dst_reg->umin_value = 0;
+	dst_reg->umax_value = U64_MAX;
+
+	/* Its not easy to operate on alu32 bounds here because it depends
+	 * on bits being shifted in from upper 32-bits. Take easy way out
+	 * and mark unbounded so we can recalculate later from tnum.
+	 */
+	__mark_reg32_unbounded(dst_reg);
+	__update_reg_bounds(dst_reg);
+}
+
+/* WARNING: This function does calculations on 64-bit values, but the actual
+ * execution may occur on 32-bit values. Therefore, things like bitshifts
+ * need extra checks in the 32-bit case.
+ */
+static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
+				      struct bpf_insn *insn,
+				      struct bpf_reg_state *dst_reg,
+				      struct bpf_reg_state src_reg)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	u8 opcode = BPF_OP(insn->code);
+	bool src_known;
+	s64 smin_val, smax_val;
+	u64 umin_val, umax_val;
+	s32 s32_min_val, s32_max_val;
+	u32 u32_min_val, u32_max_val;
+	u64 insn_bitness = (BPF_CLASS(insn->code) == BPF_ALU64) ? 64 : 32;
+	bool alu32 = (BPF_CLASS(insn->code) != BPF_ALU64);
+	int ret;
+
+	smin_val = src_reg.smin_value;
+	smax_val = src_reg.smax_value;
+	umin_val = src_reg.umin_value;
+	umax_val = src_reg.umax_value;
+
+	s32_min_val = src_reg.s32_min_value;
+	s32_max_val = src_reg.s32_max_value;
+	u32_min_val = src_reg.u32_min_value;
+	u32_max_val = src_reg.u32_max_value;
+
+	if (alu32) {
+		src_known = tnum_subreg_is_const(src_reg.var_off);
+		if ((src_known &&
+		     (s32_min_val != s32_max_val || u32_min_val != u32_max_val)) ||
+		    s32_min_val > s32_max_val || u32_min_val > u32_max_val) {
+			/* Taint dst register if offset had invalid bounds
+			 * derived from e.g. dead branches.
+			 */
+			__mark_reg_unknown(env, dst_reg);
+			return 0;
+		}
+	} else {
+		src_known = tnum_is_const(src_reg.var_off);
+		if ((src_known &&
+		     (smin_val != smax_val || umin_val != umax_val)) ||
+		    smin_val > smax_val || umin_val > umax_val) {
+			/* Taint dst register if offset had invalid bounds
+			 * derived from e.g. dead branches.
+			 */
+			__mark_reg_unknown(env, dst_reg);
+			return 0;
+		}
+	}
+
+	if (!src_known &&
+	    opcode != BPF_ADD && opcode != BPF_SUB && opcode != BPF_AND) {
+		__mark_reg_unknown(env, dst_reg);
+		return 0;
+	}
+
+	if (sanitize_needed(opcode)) {
+		ret = sanitize_val_alu(env, insn);
+		if (ret < 0)
+			return sanitize_err(env, insn, ret, NULL, NULL);
+	}
+
+	/* Calculate sign/unsigned bounds and tnum for alu32 and alu64 bit ops.
+	 * There are two classes of instructions: The first class we track both
+	 * alu32 and alu64 sign/unsigned bounds independently this provides the
+	 * greatest amount of precision when alu operations are mixed with jmp32
+	 * operations. These operations are BPF_ADD, BPF_SUB, BPF_MUL, BPF_ADD,
+	 * and BPF_OR. This is possible because these ops have fairly easy to
+	 * understand and calculate behavior in both 32-bit and 64-bit alu ops.
+	 * See alu32 verifier tests for examples. The second class of
+	 * operations, BPF_LSH, BPF_RSH, and BPF_ARSH, however are not so easy
+	 * with regards to tracking sign/unsigned bounds because the bits may
+	 * cross subreg boundaries in the alu64 case. When this happens we mark
+	 * the reg unbounded in the subreg bound space and use the resulting
+	 * tnum to calculate an approximation of the sign/unsigned bounds.
+	 */
+	switch (opcode) {
+	case BPF_ADD:
+		scalar32_min_max_add(dst_reg, &src_reg);
+		scalar_min_max_add(dst_reg, &src_reg);
+		dst_reg->var_off = tnum_add(dst_reg->var_off, src_reg.var_off);
+		break;
+	case BPF_SUB:
+		scalar32_min_max_sub(dst_reg, &src_reg);
+		scalar_min_max_sub(dst_reg, &src_reg);
+		dst_reg->var_off = tnum_sub(dst_reg->var_off, src_reg.var_off);
+		break;
+	case BPF_MUL:
+		dst_reg->var_off = tnum_mul(dst_reg->var_off, src_reg.var_off);
+		scalar32_min_max_mul(dst_reg, &src_reg);
+		scalar_min_max_mul(dst_reg, &src_reg);
+		break;
+	case BPF_AND:
+		dst_reg->var_off = tnum_and(dst_reg->var_off, src_reg.var_off);
+		scalar32_min_max_and(dst_reg, &src_reg);
+		scalar_min_max_and(dst_reg, &src_reg);
+		break;
+	case BPF_OR:
+		dst_reg->var_off = tnum_or(dst_reg->var_off, src_reg.var_off);
+		scalar32_min_max_or(dst_reg, &src_reg);
+		scalar_min_max_or(dst_reg, &src_reg);
+		break;
+	case BPF_XOR:
+		dst_reg->var_off = tnum_xor(dst_reg->var_off, src_reg.var_off);
+		scalar32_min_max_xor(dst_reg, &src_reg);
+		scalar_min_max_xor(dst_reg, &src_reg);
+		break;
+	case BPF_LSH:
+		if (umax_val >= insn_bitness) {
+			/* Shifts greater than 31 or 63 are undefined.
+			 * This includes shifts by a negative number.
+			 */
+			mark_reg_unknown(env, regs, insn->dst_reg);
+			break;
+		}
+		if (alu32)
+			scalar32_min_max_lsh(dst_reg, &src_reg);
+		else
+			scalar_min_max_lsh(dst_reg, &src_reg);
+		break;
+	case BPF_RSH:
+		if (umax_val >= insn_bitness) {
+			/* Shifts greater than 31 or 63 are undefined.
+			 * This includes shifts by a negative number.
+			 */
+			mark_reg_unknown(env, regs, insn->dst_reg);
+			break;
+		}
+		if (alu32)
+			scalar32_min_max_rsh(dst_reg, &src_reg);
+		else
+			scalar_min_max_rsh(dst_reg, &src_reg);
+		break;
+	case BPF_ARSH:
+		if (umax_val >= insn_bitness) {
+			/* Shifts greater than 31 or 63 are undefined.
+			 * This includes shifts by a negative number.
+			 */
+			mark_reg_unknown(env, regs, insn->dst_reg);
+			break;
+		}
+		if (alu32)
+			scalar32_min_max_arsh(dst_reg, &src_reg);
+		else
+			scalar_min_max_arsh(dst_reg, &src_reg);
+		break;
+	default:
+		mark_reg_unknown(env, regs, insn->dst_reg);
+		break;
+	}
+
+	/* ALU32 ops are zero extended into 64bit register */
+	if (alu32)
+		zext_32_to_64(dst_reg);
+	reg_bounds_sync(dst_reg);
+	return 0;
+}
+
+/* Handles ALU ops other than BPF_END, BPF_NEG and BPF_MOV: computes new min/max
+ * and var_off.
+ */
+static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
+				   struct bpf_insn *insn)
+{
+	struct bpf_verifier_state *vstate = env->cur_state;
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	struct bpf_reg_state *regs = state->regs, *dst_reg, *src_reg;
+	struct bpf_reg_state *ptr_reg = NULL, off_reg = {0};
+	u8 opcode = BPF_OP(insn->code);
+	int err;
+
+	dst_reg = &regs[insn->dst_reg];
+	src_reg = NULL;
+	if (dst_reg->type != SCALAR_VALUE)
+		ptr_reg = dst_reg;
+	else
+		/* Make sure ID is cleared otherwise dst_reg min/max could be
+		 * incorrectly propagated into other registers by find_equal_scalars()
+		 */
+		dst_reg->id = 0;
+	if (BPF_SRC(insn->code) == BPF_X) {
+		src_reg = &regs[insn->src_reg];
+		if (src_reg->type != SCALAR_VALUE) {
+			if (dst_reg->type != SCALAR_VALUE) {
+				/* Combining two pointers by any ALU op yields
+				 * an arbitrary scalar. Disallow all math except
+				 * pointer subtraction
+				 */
+				if (opcode == BPF_SUB && env->allow_ptr_leaks) {
+					mark_reg_unknown(env, regs, insn->dst_reg);
+					return 0;
+				}
+				verbose(env, "R%d pointer %s pointer prohibited\n",
+					insn->dst_reg,
+					bpf_alu_string[opcode >> 4]);
+				return -EACCES;
+			} else {
+				/* scalar += pointer
+				 * This is legal, but we have to reverse our
+				 * src/dest handling in computing the range
+				 */
+				err = mark_chain_precision(env, insn->dst_reg);
+				if (err)
+					return err;
+				return adjust_ptr_min_max_vals(env, insn,
+							       src_reg, dst_reg);
+			}
+		} else if (ptr_reg) {
+			/* pointer += scalar */
+			err = mark_chain_precision(env, insn->src_reg);
+			if (err)
+				return err;
+			return adjust_ptr_min_max_vals(env, insn,
+						       dst_reg, src_reg);
+		} else if (dst_reg->precise) {
+			/* if dst_reg is precise, src_reg should be precise as well */
+			err = mark_chain_precision(env, insn->src_reg);
+			if (err)
+				return err;
+		}
+	} else {
+		/* Pretend the src is a reg with a known value, since we only
+		 * need to be able to read from this state.
+		 */
+		off_reg.type = SCALAR_VALUE;
+		__mark_reg_known(&off_reg, insn->imm);
+		src_reg = &off_reg;
+		if (ptr_reg) /* pointer += K */
+			return adjust_ptr_min_max_vals(env, insn,
+						       ptr_reg, src_reg);
+	}
+
+	/* Got here implies adding two SCALAR_VALUEs */
+	if (WARN_ON_ONCE(ptr_reg)) {
+		print_verifier_state(env, state);
+		verbose(env, "verifier internal error: unexpected ptr_reg\n");
+		return -EINVAL;
+	}
+	if (WARN_ON(!src_reg)) {
+		print_verifier_state(env, state);
+		verbose(env, "verifier internal error: no src_reg\n");
+		return -EINVAL;
+	}
+	return adjust_scalar_min_max_vals(env, insn, dst_reg, *src_reg);
+}
+
+/* check validity of 32-bit and 64-bit arithmetic operations */
+static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	u8 opcode = BPF_OP(insn->code);
+	int err;
+
+	if (opcode == BPF_END || opcode == BPF_NEG) {
+		if (opcode == BPF_NEG) {
+			if (BPF_SRC(insn->code) != 0 ||
+			    insn->src_reg != BPF_REG_0 ||
+			    insn->off != 0 || insn->imm != 0) {
+				verbose(env, "BPF_NEG uses reserved fields\n");
+				return -EINVAL;
+			}
+		} else {
+			if (insn->src_reg != BPF_REG_0 || insn->off != 0 ||
+			    (insn->imm != 16 && insn->imm != 32 && insn->imm != 64) ||
+			    BPF_CLASS(insn->code) == BPF_ALU64) {
+				verbose(env, "BPF_END uses reserved fields\n");
+				return -EINVAL;
+			}
+		}
+
+		/* check src operand */
+		err = check_reg_arg(env, insn->dst_reg, SRC_OP);
+		if (err)
+			return err;
+
+		if (is_pointer_value(env, insn->dst_reg)) {
+			verbose(env, "R%d pointer arithmetic prohibited\n",
+				insn->dst_reg);
+			return -EACCES;
+		}
+
+		/* check dest operand */
+		err = check_reg_arg(env, insn->dst_reg, DST_OP);
+		if (err)
+			return err;
+
+	} else if (opcode == BPF_MOV) {
+
+		if (BPF_SRC(insn->code) == BPF_X) {
+			if (insn->imm != 0 || insn->off != 0) {
+				verbose(env, "BPF_MOV uses reserved fields\n");
+				return -EINVAL;
+			}
+
+			/* check src operand */
+			err = check_reg_arg(env, insn->src_reg, SRC_OP);
+			if (err)
+				return err;
+		} else {
+			if (insn->src_reg != BPF_REG_0 || insn->off != 0) {
+				verbose(env, "BPF_MOV uses reserved fields\n");
+				return -EINVAL;
+			}
+		}
+
+		/* check dest operand, mark as required later */
+		err = check_reg_arg(env, insn->dst_reg, DST_OP_NO_MARK);
+		if (err)
+			return err;
+
+		if (BPF_SRC(insn->code) == BPF_X) {
+			struct bpf_reg_state *src_reg = regs + insn->src_reg;
+			struct bpf_reg_state *dst_reg = regs + insn->dst_reg;
+
+			if (BPF_CLASS(insn->code) == BPF_ALU64) {
+				/* case: R1 = R2
+				 * copy register state to dest reg
+				 */
+				if (src_reg->type == SCALAR_VALUE && !src_reg->id)
+					/* Assign src and dst registers the same ID
+					 * that will be used by find_equal_scalars()
+					 * to propagate min/max range.
+					 */
+					src_reg->id = ++env->id_gen;
+				copy_register_state(dst_reg, src_reg);
+				dst_reg->live |= REG_LIVE_WRITTEN;
+				dst_reg->subreg_def = DEF_NOT_SUBREG;
+			} else {
+				/* R1 = (u32) R2 */
+				if (is_pointer_value(env, insn->src_reg)) {
+					verbose(env,
+						"R%d partial copy of pointer\n",
+						insn->src_reg);
+					return -EACCES;
+				} else if (src_reg->type == SCALAR_VALUE) {
+					copy_register_state(dst_reg, src_reg);
+					/* Make sure ID is cleared otherwise
+					 * dst_reg min/max could be incorrectly
+					 * propagated into src_reg by find_equal_scalars()
+					 */
+					dst_reg->id = 0;
+					dst_reg->live |= REG_LIVE_WRITTEN;
+					dst_reg->subreg_def = env->insn_idx + 1;
+				} else {
+					mark_reg_unknown(env, regs,
+							 insn->dst_reg);
+				}
+				zext_32_to_64(dst_reg);
+				reg_bounds_sync(dst_reg);
+			}
+		} else {
+			/* case: R = imm
+			 * remember the value we stored into this reg
+			 */
+			/* clear any state __mark_reg_known doesn't set */
+			mark_reg_unknown(env, regs, insn->dst_reg);
+			regs[insn->dst_reg].type = SCALAR_VALUE;
+			if (BPF_CLASS(insn->code) == BPF_ALU64) {
+				__mark_reg_known(regs + insn->dst_reg,
+						 insn->imm);
+			} else {
+				__mark_reg_known(regs + insn->dst_reg,
+						 (u32)insn->imm);
+			}
+		}
+
+	} else if (opcode > BPF_END) {
+		verbose(env, "invalid BPF_ALU opcode %x\n", opcode);
+		return -EINVAL;
+
+	} else {	/* all other ALU ops: and, sub, xor, add, ... */
+
+		if (BPF_SRC(insn->code) == BPF_X) {
+			if (insn->imm != 0 || insn->off != 0) {
+				verbose(env, "BPF_ALU uses reserved fields\n");
+				return -EINVAL;
+			}
+			/* check src1 operand */
+			err = check_reg_arg(env, insn->src_reg, SRC_OP);
+			if (err)
+				return err;
+		} else {
+			if (insn->src_reg != BPF_REG_0 || insn->off != 0) {
+				verbose(env, "BPF_ALU uses reserved fields\n");
+				return -EINVAL;
+			}
+		}
+
+		/* check src2 operand */
+		err = check_reg_arg(env, insn->dst_reg, SRC_OP);
+		if (err)
+			return err;
+
+		if ((opcode == BPF_MOD || opcode == BPF_DIV) &&
+		    BPF_SRC(insn->code) == BPF_K && insn->imm == 0) {
+			verbose(env, "div by zero\n");
+			return -EINVAL;
+		}
+
+		if ((opcode == BPF_LSH || opcode == BPF_RSH ||
+		     opcode == BPF_ARSH) && BPF_SRC(insn->code) == BPF_K) {
+			int size = BPF_CLASS(insn->code) == BPF_ALU64 ? 64 : 32;
+
+			if (insn->imm < 0 || insn->imm >= size) {
+				verbose(env, "invalid shift %d\n", insn->imm);
+				return -EINVAL;
+			}
+		}
+
+		/* check dest operand */
+		err = check_reg_arg(env, insn->dst_reg, DST_OP_NO_MARK);
+		if (err)
+			return err;
+
+		return adjust_reg_min_max_vals(env, insn);
+	}
+
+	return 0;
+}
+
+static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
+				   struct bpf_reg_state *dst_reg,
+				   enum bpf_reg_type type,
+				   bool range_right_open)
+{
+	struct bpf_func_state *state;
+	struct bpf_reg_state *reg;
+	int new_range;
+
+	if (dst_reg->off < 0 ||
+	    (dst_reg->off == 0 && range_right_open))
+		/* This doesn't give us any range */
+		return;
+
+	if (dst_reg->umax_value > MAX_PACKET_OFF ||
+	    dst_reg->umax_value + dst_reg->off > MAX_PACKET_OFF)
+		/* Risk of overflow.  For instance, ptr + (1<<63) may be less
+		 * than pkt_end, but that's because it's also less than pkt.
+		 */
+		return;
+
+	new_range = dst_reg->off;
+	if (range_right_open)
+		new_range++;
+
+	/* Examples for register markings:
+	 *
+	 * pkt_data in dst register:
+	 *
+	 *   r2 = r3;
+	 *   r2 += 8;
+	 *   if (r2 > pkt_end) goto <handle exception>
+	 *   <access okay>
+	 *
+	 *   r2 = r3;
+	 *   r2 += 8;
+	 *   if (r2 < pkt_end) goto <access okay>
+	 *   <handle exception>
+	 *
+	 *   Where:
+	 *     r2 == dst_reg, pkt_end == src_reg
+	 *     r2=pkt(id=n,off=8,r=0)
+	 *     r3=pkt(id=n,off=0,r=0)
+	 *
+	 * pkt_data in src register:
+	 *
+	 *   r2 = r3;
+	 *   r2 += 8;
+	 *   if (pkt_end >= r2) goto <access okay>
+	 *   <handle exception>
+	 *
+	 *   r2 = r3;
+	 *   r2 += 8;
+	 *   if (pkt_end <= r2) goto <handle exception>
+	 *   <access okay>
+	 *
+	 *   Where:
+	 *     pkt_end == dst_reg, r2 == src_reg
+	 *     r2=pkt(id=n,off=8,r=0)
+	 *     r3=pkt(id=n,off=0,r=0)
+	 *
+	 * Find register r3 and mark its range as r3=pkt(id=n,off=0,r=8)
+	 * or r3=pkt(id=n,off=0,r=8-1), so that range of bytes [r3, r3 + 8)
+	 * and [r3, r3 + 8-1) respectively is safe to access depending on
+	 * the check.
+	 */
+
+	/* If our ids match, then we must have the same max_value.  And we
+	 * don't care about the other reg's fixed offset, since if it's too big
+	 * the range won't allow anything.
+	 * dst_reg->off is known < MAX_PACKET_OFF, therefore it fits in a u16.
+	 */
+	bpf_for_each_reg_in_vstate(vstate, state, reg, ({
+		if (reg->type == type && reg->id == dst_reg->id)
+			/* keep the maximum range already checked */
+			reg->range = max(reg->range, new_range);
+	}));
+}
+
+static int is_branch32_taken(struct bpf_reg_state *reg, u32 val, u8 opcode)
+{
+	struct tnum subreg = tnum_subreg(reg->var_off);
+	s32 sval = (s32)val;
+
+	switch (opcode) {
+	case BPF_JEQ:
+		if (tnum_is_const(subreg))
+			return !!tnum_equals_const(subreg, val);
+		break;
+	case BPF_JNE:
+		if (tnum_is_const(subreg))
+			return !tnum_equals_const(subreg, val);
+		break;
+	case BPF_JSET:
+		if ((~subreg.mask & subreg.value) & val)
+			return 1;
+		if (!((subreg.mask | subreg.value) & val))
+			return 0;
+		break;
+	case BPF_JGT:
+		if (reg->u32_min_value > val)
+			return 1;
+		else if (reg->u32_max_value <= val)
+			return 0;
+		break;
+	case BPF_JSGT:
+		if (reg->s32_min_value > sval)
+			return 1;
+		else if (reg->s32_max_value <= sval)
+			return 0;
+		break;
+	case BPF_JLT:
+		if (reg->u32_max_value < val)
+			return 1;
+		else if (reg->u32_min_value >= val)
+			return 0;
+		break;
+	case BPF_JSLT:
+		if (reg->s32_max_value < sval)
+			return 1;
+		else if (reg->s32_min_value >= sval)
+			return 0;
+		break;
+	case BPF_JGE:
+		if (reg->u32_min_value >= val)
+			return 1;
+		else if (reg->u32_max_value < val)
+			return 0;
+		break;
+	case BPF_JSGE:
+		if (reg->s32_min_value >= sval)
+			return 1;
+		else if (reg->s32_max_value < sval)
+			return 0;
+		break;
+	case BPF_JLE:
+		if (reg->u32_max_value <= val)
+			return 1;
+		else if (reg->u32_min_value > val)
+			return 0;
+		break;
+	case BPF_JSLE:
+		if (reg->s32_max_value <= sval)
+			return 1;
+		else if (reg->s32_min_value > sval)
+			return 0;
+		break;
+	}
+
+	return -1;
+}
+
+
+static int is_branch64_taken(struct bpf_reg_state *reg, u64 val, u8 opcode)
+{
+	s64 sval = (s64)val;
+
+	switch (opcode) {
+	case BPF_JEQ:
+		if (tnum_is_const(reg->var_off))
+			return !!tnum_equals_const(reg->var_off, val);
+		break;
+	case BPF_JNE:
+		if (tnum_is_const(reg->var_off))
+			return !tnum_equals_const(reg->var_off, val);
+		break;
+	case BPF_JSET:
+		if ((~reg->var_off.mask & reg->var_off.value) & val)
+			return 1;
+		if (!((reg->var_off.mask | reg->var_off.value) & val))
+			return 0;
+		break;
+	case BPF_JGT:
+		if (reg->umin_value > val)
+			return 1;
+		else if (reg->umax_value <= val)
+			return 0;
+		break;
+	case BPF_JSGT:
+		if (reg->smin_value > sval)
+			return 1;
+		else if (reg->smax_value <= sval)
+			return 0;
+		break;
+	case BPF_JLT:
+		if (reg->umax_value < val)
+			return 1;
+		else if (reg->umin_value >= val)
+			return 0;
+		break;
+	case BPF_JSLT:
+		if (reg->smax_value < sval)
+			return 1;
+		else if (reg->smin_value >= sval)
+			return 0;
+		break;
+	case BPF_JGE:
+		if (reg->umin_value >= val)
+			return 1;
+		else if (reg->umax_value < val)
+			return 0;
+		break;
+	case BPF_JSGE:
+		if (reg->smin_value >= sval)
+			return 1;
+		else if (reg->smax_value < sval)
+			return 0;
+		break;
+	case BPF_JLE:
+		if (reg->umax_value <= val)
+			return 1;
+		else if (reg->umin_value > val)
+			return 0;
+		break;
+	case BPF_JSLE:
+		if (reg->smax_value <= sval)
+			return 1;
+		else if (reg->smin_value > sval)
+			return 0;
+		break;
+	}
+
+	return -1;
+}
+
+/* compute branch direction of the expression "if (reg opcode val) goto target;"
+ * and return:
+ *  1 - branch will be taken and "goto target" will be executed
+ *  0 - branch will not be taken and fall-through to next insn
+ * -1 - unknown. Example: "if (reg < 5)" is unknown when register value
+ *      range [0,10]
+ */
+static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode,
+			   bool is_jmp32)
+{
+	if (__is_pointer_value(false, reg)) {
+		if (!reg_type_not_null(reg->type))
+			return -1;
+
+		/* If pointer is valid tests against zero will fail so we can
+		 * use this to direct branch taken.
+		 */
+		if (val != 0)
+			return -1;
+
+		switch (opcode) {
+		case BPF_JEQ:
+			return 0;
+		case BPF_JNE:
+			return 1;
+		default:
+			return -1;
+		}
+	}
+
+	if (is_jmp32)
+		return is_branch32_taken(reg, val, opcode);
+	return is_branch64_taken(reg, val, opcode);
+}
+
+static int flip_opcode(u32 opcode)
+{
+	/* How can we transform "a <op> b" into "b <op> a"? */
+	static const u8 opcode_flip[16] = {
+		/* these stay the same */
+		[BPF_JEQ  >> 4] = BPF_JEQ,
+		[BPF_JNE  >> 4] = BPF_JNE,
+		[BPF_JSET >> 4] = BPF_JSET,
+		/* these swap "lesser" and "greater" (L and G in the opcodes) */
+		[BPF_JGE  >> 4] = BPF_JLE,
+		[BPF_JGT  >> 4] = BPF_JLT,
+		[BPF_JLE  >> 4] = BPF_JGE,
+		[BPF_JLT  >> 4] = BPF_JGT,
+		[BPF_JSGE >> 4] = BPF_JSLE,
+		[BPF_JSGT >> 4] = BPF_JSLT,
+		[BPF_JSLE >> 4] = BPF_JSGE,
+		[BPF_JSLT >> 4] = BPF_JSGT
+	};
+	return opcode_flip[opcode >> 4];
+}
+
+static int is_pkt_ptr_branch_taken(struct bpf_reg_state *dst_reg,
+				   struct bpf_reg_state *src_reg,
+				   u8 opcode)
+{
+	struct bpf_reg_state *pkt;
+
+	if (src_reg->type == PTR_TO_PACKET_END) {
+		pkt = dst_reg;
+	} else if (dst_reg->type == PTR_TO_PACKET_END) {
+		pkt = src_reg;
+		opcode = flip_opcode(opcode);
+	} else {
+		return -1;
+	}
+
+	if (pkt->range >= 0)
+		return -1;
+
+	switch (opcode) {
+	case BPF_JLE:
+		/* pkt <= pkt_end */
+		fallthrough;
+	case BPF_JGT:
+		/* pkt > pkt_end */
+		if (pkt->range == BEYOND_PKT_END)
+			/* pkt has at last one extra byte beyond pkt_end */
+			return opcode == BPF_JGT;
+		break;
+	case BPF_JLT:
+		/* pkt < pkt_end */
+		fallthrough;
+	case BPF_JGE:
+		/* pkt >= pkt_end */
+		if (pkt->range == BEYOND_PKT_END || pkt->range == AT_PKT_END)
+			return opcode == BPF_JGE;
+		break;
+	}
+	return -1;
+}
+
+/* Adjusts the register min/max values in the case that the dst_reg is the
+ * variable register that we are working on, and src_reg is a constant or we're
+ * simply doing a BPF_K check.
+ * In JEQ/JNE cases we also adjust the var_off values.
+ */
+static void reg_set_min_max(struct bpf_reg_state *true_reg,
+			    struct bpf_reg_state *false_reg,
+			    u64 val, u32 val32,
+			    u8 opcode, bool is_jmp32)
+{
+	struct tnum false_32off = tnum_subreg(false_reg->var_off);
+	struct tnum false_64off = false_reg->var_off;
+	struct tnum true_32off = tnum_subreg(true_reg->var_off);
+	struct tnum true_64off = true_reg->var_off;
+	s64 sval = (s64)val;
+	s32 sval32 = (s32)val32;
+
+	/* If the dst_reg is a pointer, we can't learn anything about its
+	 * variable offset from the compare (unless src_reg were a pointer into
+	 * the same object, but we don't bother with that.
+	 * Since false_reg and true_reg have the same type by construction, we
+	 * only need to check one of them for pointerness.
+	 */
+	if (__is_pointer_value(false, false_reg))
+		return;
+
+	switch (opcode) {
+	/* JEQ/JNE comparison doesn't change the register equivalence.
+	 *
+	 * r1 = r2;
+	 * if (r1 == 42) goto label;
+	 * ...
+	 * label: // here both r1 and r2 are known to be 42.
+	 *
+	 * Hence when marking register as known preserve it's ID.
+	 */
+	case BPF_JEQ:
+		if (is_jmp32) {
+			__mark_reg32_known(true_reg, val32);
+			true_32off = tnum_subreg(true_reg->var_off);
+		} else {
+			___mark_reg_known(true_reg, val);
+			true_64off = true_reg->var_off;
+		}
+		break;
+	case BPF_JNE:
+		if (is_jmp32) {
+			__mark_reg32_known(false_reg, val32);
+			false_32off = tnum_subreg(false_reg->var_off);
+		} else {
+			___mark_reg_known(false_reg, val);
+			false_64off = false_reg->var_off;
+		}
+		break;
+	case BPF_JSET:
+		if (is_jmp32) {
+			false_32off = tnum_and(false_32off, tnum_const(~val32));
+			if (is_power_of_2(val32))
+				true_32off = tnum_or(true_32off,
+						     tnum_const(val32));
+		} else {
+			false_64off = tnum_and(false_64off, tnum_const(~val));
+			if (is_power_of_2(val))
+				true_64off = tnum_or(true_64off,
+						     tnum_const(val));
+		}
+		break;
+	case BPF_JGE:
+	case BPF_JGT:
+	{
+		if (is_jmp32) {
+			u32 false_umax = opcode == BPF_JGT ? val32  : val32 - 1;
+			u32 true_umin = opcode == BPF_JGT ? val32 + 1 : val32;
+
+			false_reg->u32_max_value = min(false_reg->u32_max_value,
+						       false_umax);
+			true_reg->u32_min_value = max(true_reg->u32_min_value,
+						      true_umin);
+		} else {
+			u64 false_umax = opcode == BPF_JGT ? val    : val - 1;
+			u64 true_umin = opcode == BPF_JGT ? val + 1 : val;
+
+			false_reg->umax_value = min(false_reg->umax_value, false_umax);
+			true_reg->umin_value = max(true_reg->umin_value, true_umin);
+		}
+		break;
+	}
+	case BPF_JSGE:
+	case BPF_JSGT:
+	{
+		if (is_jmp32) {
+			s32 false_smax = opcode == BPF_JSGT ? sval32    : sval32 - 1;
+			s32 true_smin = opcode == BPF_JSGT ? sval32 + 1 : sval32;
+
+			false_reg->s32_max_value = min(false_reg->s32_max_value, false_smax);
+			true_reg->s32_min_value = max(true_reg->s32_min_value, true_smin);
+		} else {
+			s64 false_smax = opcode == BPF_JSGT ? sval    : sval - 1;
+			s64 true_smin = opcode == BPF_JSGT ? sval + 1 : sval;
+
+			false_reg->smax_value = min(false_reg->smax_value, false_smax);
+			true_reg->smin_value = max(true_reg->smin_value, true_smin);
+		}
+		break;
+	}
+	case BPF_JLE:
+	case BPF_JLT:
+	{
+		if (is_jmp32) {
+			u32 false_umin = opcode == BPF_JLT ? val32  : val32 + 1;
+			u32 true_umax = opcode == BPF_JLT ? val32 - 1 : val32;
+
+			false_reg->u32_min_value = max(false_reg->u32_min_value,
+						       false_umin);
+			true_reg->u32_max_value = min(true_reg->u32_max_value,
+						      true_umax);
+		} else {
+			u64 false_umin = opcode == BPF_JLT ? val    : val + 1;
+			u64 true_umax = opcode == BPF_JLT ? val - 1 : val;
+
+			false_reg->umin_value = max(false_reg->umin_value, false_umin);
+			true_reg->umax_value = min(true_reg->umax_value, true_umax);
+		}
+		break;
+	}
+	case BPF_JSLE:
+	case BPF_JSLT:
+	{
+		if (is_jmp32) {
+			s32 false_smin = opcode == BPF_JSLT ? sval32    : sval32 + 1;
+			s32 true_smax = opcode == BPF_JSLT ? sval32 - 1 : sval32;
+
+			false_reg->s32_min_value = max(false_reg->s32_min_value, false_smin);
+			true_reg->s32_max_value = min(true_reg->s32_max_value, true_smax);
+		} else {
+			s64 false_smin = opcode == BPF_JSLT ? sval    : sval + 1;
+			s64 true_smax = opcode == BPF_JSLT ? sval - 1 : sval;
+
+			false_reg->smin_value = max(false_reg->smin_value, false_smin);
+			true_reg->smax_value = min(true_reg->smax_value, true_smax);
+		}
+		break;
+	}
+	default:
+		return;
+	}
+
+	if (is_jmp32) {
+		false_reg->var_off = tnum_or(tnum_clear_subreg(false_64off),
+					     tnum_subreg(false_32off));
+		true_reg->var_off = tnum_or(tnum_clear_subreg(true_64off),
+					    tnum_subreg(true_32off));
+		__reg_combine_32_into_64(false_reg);
+		__reg_combine_32_into_64(true_reg);
+	} else {
+		false_reg->var_off = false_64off;
+		true_reg->var_off = true_64off;
+		__reg_combine_64_into_32(false_reg);
+		__reg_combine_64_into_32(true_reg);
+	}
+}
+
+/* Same as above, but for the case that dst_reg holds a constant and src_reg is
+ * the variable reg.
+ */
+static void reg_set_min_max_inv(struct bpf_reg_state *true_reg,
+				struct bpf_reg_state *false_reg,
+				u64 val, u32 val32,
+				u8 opcode, bool is_jmp32)
+{
+	opcode = flip_opcode(opcode);
+	/* This uses zero as "not present in table"; luckily the zero opcode,
+	 * BPF_JA, can't get here.
+	 */
+	if (opcode)
+		reg_set_min_max(true_reg, false_reg, val, val32, opcode, is_jmp32);
+}
+
+/* Regs are known to be equal, so intersect their min/max/var_off */
+static void __reg_combine_min_max(struct bpf_reg_state *src_reg,
+				  struct bpf_reg_state *dst_reg)
+{
+	src_reg->umin_value = dst_reg->umin_value = max(src_reg->umin_value,
+							dst_reg->umin_value);
+	src_reg->umax_value = dst_reg->umax_value = min(src_reg->umax_value,
+							dst_reg->umax_value);
+	src_reg->smin_value = dst_reg->smin_value = max(src_reg->smin_value,
+							dst_reg->smin_value);
+	src_reg->smax_value = dst_reg->smax_value = min(src_reg->smax_value,
+							dst_reg->smax_value);
+	src_reg->var_off = dst_reg->var_off = tnum_intersect(src_reg->var_off,
+							     dst_reg->var_off);
+	reg_bounds_sync(src_reg);
+	reg_bounds_sync(dst_reg);
+}
+
+static void reg_combine_min_max(struct bpf_reg_state *true_src,
+				struct bpf_reg_state *true_dst,
+				struct bpf_reg_state *false_src,
+				struct bpf_reg_state *false_dst,
+				u8 opcode)
+{
+	switch (opcode) {
+	case BPF_JEQ:
+		__reg_combine_min_max(true_src, true_dst);
+		break;
+	case BPF_JNE:
+		__reg_combine_min_max(false_src, false_dst);
+		break;
+	}
+}
+
+static void mark_ptr_or_null_reg(struct bpf_func_state *state,
+				 struct bpf_reg_state *reg, u32 id,
+				 bool is_null)
+{
+	if (reg_type_may_be_null(reg->type) && reg->id == id &&
+	    !WARN_ON_ONCE(!reg->id)) {
+		if (WARN_ON_ONCE(reg->smin_value || reg->smax_value ||
+				 !tnum_equals_const(reg->var_off, 0) ||
+				 reg->off)) {
+			/* Old offset (both fixed and variable parts) should
+			 * have been known-zero, because we don't allow pointer
+			 * arithmetic on pointers that might be NULL. If we
+			 * see this happening, don't convert the register.
+			 */
+			return;
+		}
+		if (is_null) {
+			reg->type = SCALAR_VALUE;
+		} else if (reg->type == PTR_TO_MAP_VALUE_OR_NULL) {
+			const struct bpf_map *map = reg->map_ptr;
+
+			if (map->inner_map_meta) {
+				reg->type = CONST_PTR_TO_MAP;
+				reg->map_ptr = map->inner_map_meta;
+			} else if (map->map_type == BPF_MAP_TYPE_XSKMAP) {
+				reg->type = PTR_TO_XDP_SOCK;
+			} else if (map->map_type == BPF_MAP_TYPE_SOCKMAP ||
+				   map->map_type == BPF_MAP_TYPE_SOCKHASH) {
+				reg->type = PTR_TO_SOCKET;
+			} else {
+				reg->type = PTR_TO_MAP_VALUE;
+			}
+		} else if (reg->type == PTR_TO_SOCKET_OR_NULL) {
+			reg->type = PTR_TO_SOCKET;
+		} else if (reg->type == PTR_TO_SOCK_COMMON_OR_NULL) {
+			reg->type = PTR_TO_SOCK_COMMON;
+		} else if (reg->type == PTR_TO_TCP_SOCK_OR_NULL) {
+			reg->type = PTR_TO_TCP_SOCK;
+		} else if (reg->type == PTR_TO_BTF_ID_OR_NULL) {
+			reg->type = PTR_TO_BTF_ID;
+		} else if (reg->type == PTR_TO_MEM_OR_NULL) {
+			reg->type = PTR_TO_MEM;
+		} else if (reg->type == PTR_TO_RDONLY_BUF_OR_NULL) {
+			reg->type = PTR_TO_RDONLY_BUF;
+		} else if (reg->type == PTR_TO_RDWR_BUF_OR_NULL) {
+			reg->type = PTR_TO_RDWR_BUF;
+		}
+		if (is_null) {
+			/* We don't need id and ref_obj_id from this point
+			 * onwards anymore, thus we should better reset it,
+			 * so that state pruning has chances to take effect.
+			 */
+			reg->id = 0;
+			reg->ref_obj_id = 0;
+		} else if (!reg_may_point_to_spin_lock(reg)) {
+			/* For not-NULL ptr, reg->ref_obj_id will be reset
+			 * in release_reference().
+			 *
+			 * reg->id is still used by spin_lock ptr. Other
+			 * than spin_lock ptr type, reg->id can be reset.
+			 */
+			reg->id = 0;
+		}
+	}
+}
+
+/* The logic is similar to find_good_pkt_pointers(), both could eventually
+ * be folded together at some point.
+ */
+static void mark_ptr_or_null_regs(struct bpf_verifier_state *vstate, u32 regno,
+				  bool is_null)
+{
+	struct bpf_func_state *state = vstate->frame[vstate->curframe];
+	struct bpf_reg_state *regs = state->regs, *reg;
+	u32 ref_obj_id = regs[regno].ref_obj_id;
+	u32 id = regs[regno].id;
+
+	if (ref_obj_id && ref_obj_id == id && is_null)
+		/* regs[regno] is in the " == NULL" branch.
+		 * No one could have freed the reference state before
+		 * doing the NULL check.
+		 */
+		WARN_ON_ONCE(release_reference_state(state, id));
+
+	bpf_for_each_reg_in_vstate(vstate, state, reg, ({
+		mark_ptr_or_null_reg(state, reg, id, is_null);
+	}));
+}
+
+static bool try_match_pkt_pointers(const struct bpf_insn *insn,
+				   struct bpf_reg_state *dst_reg,
+				   struct bpf_reg_state *src_reg,
+				   struct bpf_verifier_state *this_branch,
+				   struct bpf_verifier_state *other_branch)
+{
+	if (BPF_SRC(insn->code) != BPF_X)
+		return false;
+
+	/* Pointers are always 64-bit. */
+	if (BPF_CLASS(insn->code) == BPF_JMP32)
+		return false;
+
+	switch (BPF_OP(insn->code)) {
+	case BPF_JGT:
+		if ((dst_reg->type == PTR_TO_PACKET &&
+		     src_reg->type == PTR_TO_PACKET_END) ||
+		    (dst_reg->type == PTR_TO_PACKET_META &&
+		     reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) {
+			/* pkt_data' > pkt_end, pkt_meta' > pkt_data */
+			find_good_pkt_pointers(this_branch, dst_reg,
+					       dst_reg->type, false);
+			mark_pkt_end(other_branch, insn->dst_reg, true);
+		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
+			    src_reg->type == PTR_TO_PACKET) ||
+			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
+			    src_reg->type == PTR_TO_PACKET_META)) {
+			/* pkt_end > pkt_data', pkt_data > pkt_meta' */
+			find_good_pkt_pointers(other_branch, src_reg,
+					       src_reg->type, true);
+			mark_pkt_end(this_branch, insn->src_reg, false);
+		} else {
+			return false;
+		}
+		break;
+	case BPF_JLT:
+		if ((dst_reg->type == PTR_TO_PACKET &&
+		     src_reg->type == PTR_TO_PACKET_END) ||
+		    (dst_reg->type == PTR_TO_PACKET_META &&
+		     reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) {
+			/* pkt_data' < pkt_end, pkt_meta' < pkt_data */
+			find_good_pkt_pointers(other_branch, dst_reg,
+					       dst_reg->type, true);
+			mark_pkt_end(this_branch, insn->dst_reg, false);
+		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
+			    src_reg->type == PTR_TO_PACKET) ||
+			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
+			    src_reg->type == PTR_TO_PACKET_META)) {
+			/* pkt_end < pkt_data', pkt_data > pkt_meta' */
+			find_good_pkt_pointers(this_branch, src_reg,
+					       src_reg->type, false);
+			mark_pkt_end(other_branch, insn->src_reg, true);
+		} else {
+			return false;
+		}
+		break;
+	case BPF_JGE:
+		if ((dst_reg->type == PTR_TO_PACKET &&
+		     src_reg->type == PTR_TO_PACKET_END) ||
+		    (dst_reg->type == PTR_TO_PACKET_META &&
+		     reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) {
+			/* pkt_data' >= pkt_end, pkt_meta' >= pkt_data */
+			find_good_pkt_pointers(this_branch, dst_reg,
+					       dst_reg->type, true);
+			mark_pkt_end(other_branch, insn->dst_reg, false);
+		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
+			    src_reg->type == PTR_TO_PACKET) ||
+			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
+			    src_reg->type == PTR_TO_PACKET_META)) {
+			/* pkt_end >= pkt_data', pkt_data >= pkt_meta' */
+			find_good_pkt_pointers(other_branch, src_reg,
+					       src_reg->type, false);
+			mark_pkt_end(this_branch, insn->src_reg, true);
+		} else {
+			return false;
+		}
+		break;
+	case BPF_JLE:
+		if ((dst_reg->type == PTR_TO_PACKET &&
+		     src_reg->type == PTR_TO_PACKET_END) ||
+		    (dst_reg->type == PTR_TO_PACKET_META &&
+		     reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) {
+			/* pkt_data' <= pkt_end, pkt_meta' <= pkt_data */
+			find_good_pkt_pointers(other_branch, dst_reg,
+					       dst_reg->type, false);
+			mark_pkt_end(this_branch, insn->dst_reg, true);
+		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
+			    src_reg->type == PTR_TO_PACKET) ||
+			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
+			    src_reg->type == PTR_TO_PACKET_META)) {
+			/* pkt_end <= pkt_data', pkt_data <= pkt_meta' */
+			find_good_pkt_pointers(this_branch, src_reg,
+					       src_reg->type, true);
+			mark_pkt_end(other_branch, insn->src_reg, false);
+		} else {
+			return false;
+		}
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+static void find_equal_scalars(struct bpf_verifier_state *vstate,
+			       struct bpf_reg_state *known_reg)
+{
+	struct bpf_func_state *state;
+	struct bpf_reg_state *reg;
+
+	bpf_for_each_reg_in_vstate(vstate, state, reg, ({
+		if (reg->type == SCALAR_VALUE && reg->id == known_reg->id)
+			copy_register_state(reg, known_reg);
+	}));
+}
+
+static int check_cond_jmp_op(struct bpf_verifier_env *env,
+			     struct bpf_insn *insn, int *insn_idx)
+{
+	struct bpf_verifier_state *this_branch = env->cur_state;
+	struct bpf_verifier_state *other_branch;
+	struct bpf_reg_state *regs = this_branch->frame[this_branch->curframe]->regs;
+	struct bpf_reg_state *dst_reg, *other_branch_regs, *src_reg = NULL;
+	u8 opcode = BPF_OP(insn->code);
+	bool is_jmp32;
+	int pred = -1;
+	int err;
+
+	/* Only conditional jumps are expected to reach here. */
+	if (opcode == BPF_JA || opcode > BPF_JSLE) {
+		verbose(env, "invalid BPF_JMP/JMP32 opcode %x\n", opcode);
+		return -EINVAL;
+	}
+
+	if (BPF_SRC(insn->code) == BPF_X) {
+		if (insn->imm != 0) {
+			verbose(env, "BPF_JMP/JMP32 uses reserved fields\n");
+			return -EINVAL;
+		}
+
+		/* check src1 operand */
+		err = check_reg_arg(env, insn->src_reg, SRC_OP);
+		if (err)
+			return err;
+
+		if (is_pointer_value(env, insn->src_reg)) {
+			verbose(env, "R%d pointer comparison prohibited\n",
+				insn->src_reg);
+			return -EACCES;
+		}
+		src_reg = &regs[insn->src_reg];
+	} else {
+		if (insn->src_reg != BPF_REG_0) {
+			verbose(env, "BPF_JMP/JMP32 uses reserved fields\n");
+			return -EINVAL;
+		}
+	}
+
+	/* check src2 operand */
+	err = check_reg_arg(env, insn->dst_reg, SRC_OP);
+	if (err)
+		return err;
+
+	dst_reg = &regs[insn->dst_reg];
+	is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
+
+	if (BPF_SRC(insn->code) == BPF_K) {
+		pred = is_branch_taken(dst_reg, insn->imm, opcode, is_jmp32);
+	} else if (src_reg->type == SCALAR_VALUE &&
+		   is_jmp32 && tnum_is_const(tnum_subreg(src_reg->var_off))) {
+		pred = is_branch_taken(dst_reg,
+				       tnum_subreg(src_reg->var_off).value,
+				       opcode,
+				       is_jmp32);
+	} else if (src_reg->type == SCALAR_VALUE &&
+		   !is_jmp32 && tnum_is_const(src_reg->var_off)) {
+		pred = is_branch_taken(dst_reg,
+				       src_reg->var_off.value,
+				       opcode,
+				       is_jmp32);
+	} else if (reg_is_pkt_pointer_any(dst_reg) &&
+		   reg_is_pkt_pointer_any(src_reg) &&
+		   !is_jmp32) {
+		pred = is_pkt_ptr_branch_taken(dst_reg, src_reg, opcode);
+	}
+
+	if (pred >= 0) {
+		/* If we get here with a dst_reg pointer type it is because
+		 * above is_branch_taken() special cased the 0 comparison.
+		 */
+		if (!__is_pointer_value(false, dst_reg))
+			err = mark_chain_precision(env, insn->dst_reg);
+		if (BPF_SRC(insn->code) == BPF_X && !err &&
+		    !__is_pointer_value(false, src_reg))
+			err = mark_chain_precision(env, insn->src_reg);
+		if (err)
+			return err;
+	}
+
+	if (pred == 1) {
+		/* Only follow the goto, ignore fall-through. If needed, push
+		 * the fall-through branch for simulation under speculative
+		 * execution.
+		 */
+		if (!env->bypass_spec_v1 &&
+		    !sanitize_speculative_path(env, insn, *insn_idx + 1,
+					       *insn_idx))
+			return -EFAULT;
+		*insn_idx += insn->off;
+		return 0;
+	} else if (pred == 0) {
+		/* Only follow the fall-through branch, since that's where the
+		 * program will go. If needed, push the goto branch for
+		 * simulation under speculative execution.
+		 */
+		if (!env->bypass_spec_v1 &&
+		    !sanitize_speculative_path(env, insn,
+					       *insn_idx + insn->off + 1,
+					       *insn_idx))
+			return -EFAULT;
+		return 0;
+	}
+
+	other_branch = push_stack(env, *insn_idx + insn->off + 1, *insn_idx,
+				  false);
+	if (!other_branch)
+		return -EFAULT;
+	other_branch_regs = other_branch->frame[other_branch->curframe]->regs;
+
+	/* detect if we are comparing against a constant value so we can adjust
+	 * our min/max values for our dst register.
+	 * this is only legit if both are scalars (or pointers to the same
+	 * object, I suppose, but we don't support that right now), because
+	 * otherwise the different base pointers mean the offsets aren't
+	 * comparable.
+	 */
+	if (BPF_SRC(insn->code) == BPF_X) {
+		struct bpf_reg_state *src_reg = &regs[insn->src_reg];
+
+		if (dst_reg->type == SCALAR_VALUE &&
+		    src_reg->type == SCALAR_VALUE) {
+			if (tnum_is_const(src_reg->var_off) ||
+			    (is_jmp32 &&
+			     tnum_is_const(tnum_subreg(src_reg->var_off))))
+				reg_set_min_max(&other_branch_regs[insn->dst_reg],
+						dst_reg,
+						src_reg->var_off.value,
+						tnum_subreg(src_reg->var_off).value,
+						opcode, is_jmp32);
+			else if (tnum_is_const(dst_reg->var_off) ||
+				 (is_jmp32 &&
+				  tnum_is_const(tnum_subreg(dst_reg->var_off))))
+				reg_set_min_max_inv(&other_branch_regs[insn->src_reg],
+						    src_reg,
+						    dst_reg->var_off.value,
+						    tnum_subreg(dst_reg->var_off).value,
+						    opcode, is_jmp32);
+			else if (!is_jmp32 &&
+				 (opcode == BPF_JEQ || opcode == BPF_JNE))
+				/* Comparing for equality, we can combine knowledge */
+				reg_combine_min_max(&other_branch_regs[insn->src_reg],
+						    &other_branch_regs[insn->dst_reg],
+						    src_reg, dst_reg, opcode);
+			if (src_reg->id &&
+			    !WARN_ON_ONCE(src_reg->id != other_branch_regs[insn->src_reg].id)) {
+				find_equal_scalars(this_branch, src_reg);
+				find_equal_scalars(other_branch, &other_branch_regs[insn->src_reg]);
+			}
+
+		}
+	} else if (dst_reg->type == SCALAR_VALUE) {
+		reg_set_min_max(&other_branch_regs[insn->dst_reg],
+					dst_reg, insn->imm, (u32)insn->imm,
+					opcode, is_jmp32);
+	}
+
+	if (dst_reg->type == SCALAR_VALUE && dst_reg->id &&
+	    !WARN_ON_ONCE(dst_reg->id != other_branch_regs[insn->dst_reg].id)) {
+		find_equal_scalars(this_branch, dst_reg);
+		find_equal_scalars(other_branch, &other_branch_regs[insn->dst_reg]);
+	}
+
+	/* detect if R == 0 where R is returned from bpf_map_lookup_elem().
+	 * NOTE: these optimizations below are related with pointer comparison
+	 *       which will never be JMP32.
+	 */
+	if (!is_jmp32 && BPF_SRC(insn->code) == BPF_K &&
+	    insn->imm == 0 && (opcode == BPF_JEQ || opcode == BPF_JNE) &&
+	    reg_type_may_be_null(dst_reg->type)) {
+		/* Mark all identical registers in each branch as either
+		 * safe or unknown depending R == 0 or R != 0 conditional.
+		 */
+		mark_ptr_or_null_regs(this_branch, insn->dst_reg,
+				      opcode == BPF_JNE);
+		mark_ptr_or_null_regs(other_branch, insn->dst_reg,
+				      opcode == BPF_JEQ);
+	} else if (!try_match_pkt_pointers(insn, dst_reg, &regs[insn->src_reg],
+					   this_branch, other_branch) &&
+		   is_pointer_value(env, insn->dst_reg)) {
+		verbose(env, "R%d pointer comparison prohibited\n",
+			insn->dst_reg);
+		return -EACCES;
+	}
+	if (env->log.level & BPF_LOG_LEVEL)
+		print_verifier_state(env, this_branch->frame[this_branch->curframe]);
+	return 0;
+}
+
+/* verify BPF_LD_IMM64 instruction */
+static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
+{
+	struct bpf_insn_aux_data *aux = cur_aux(env);
+	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_reg_state *dst_reg;
+	struct bpf_map *map;
+	int err;
+
+	if (BPF_SIZE(insn->code) != BPF_DW) {
+		verbose(env, "invalid BPF_LD_IMM insn\n");
+		return -EINVAL;
+	}
+	if (insn->off != 0) {
+		verbose(env, "BPF_LD_IMM64 uses reserved fields\n");
+		return -EINVAL;
+	}
+
+	err = check_reg_arg(env, insn->dst_reg, DST_OP);
+	if (err)
+		return err;
+
+	dst_reg = &regs[insn->dst_reg];
+	if (insn->src_reg == 0) {
+		u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;
+
+		dst_reg->type = SCALAR_VALUE;
+		__mark_reg_known(&regs[insn->dst_reg], imm);
+		return 0;
+	}
+
+	if (insn->src_reg == BPF_PSEUDO_BTF_ID) {
+		mark_reg_known_zero(env, regs, insn->dst_reg);
+
+		dst_reg->type = aux->btf_var.reg_type;
+		switch (dst_reg->type) {
+		case PTR_TO_MEM:
+			dst_reg->mem_size = aux->btf_var.mem_size;
+			break;
+		case PTR_TO_BTF_ID:
+		case PTR_TO_PERCPU_BTF_ID:
+			dst_reg->btf_id = aux->btf_var.btf_id;
+			break;
+		default:
+			verbose(env, "bpf verifier is misconfigured\n");
+			return -EFAULT;
+		}
+		return 0;
+	}
+
+	map = env->used_maps[aux->map_index];
+	mark_reg_known_zero(env, regs, insn->dst_reg);
+	dst_reg->map_ptr = map;
+
+	if (insn->src_reg == BPF_PSEUDO_MAP_VALUE) {
+		dst_reg->type = PTR_TO_MAP_VALUE;
+		dst_reg->off = aux->map_off;
+		if (map_value_has_spin_lock(map))
+			dst_reg->id = ++env->id_gen;
+	} else if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+		dst_reg->type = CONST_PTR_TO_MAP;
+	} else {
+		verbose(env, "bpf verifier is misconfigured\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static bool may_access_skb(enum bpf_prog_type type)
+{
+	switch (type) {
+	case BPF_PROG_TYPE_SOCKET_FILTER:
+	case BPF_PROG_TYPE_SCHED_CLS:
+	case BPF_PROG_TYPE_SCHED_ACT:
+		return true;
+	default:
+		return false;
+	}
+}
+
+/* verify safety of LD_ABS|LD_IND instructions:
+ * - they can only appear in the programs where ctx == skb
+ * - since they are wrappers of function calls, they scratch R1-R5 registers,
+ *   preserve R6-R9, and store return value into R0
+ *
+ * Implicit input:
+ *   ctx == skb == R6 == CTX
+ *
+ * Explicit input:
+ *   SRC == any register
+ *   IMM == 32-bit immediate
+ *
+ * Output:
+ *   R0 - 8/16/32-bit skb data converted to cpu endianness
+ */
+static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	static const int ctx_reg = BPF_REG_6;
+	u8 mode = BPF_MODE(insn->code);
+	int i, err;
+
+	if (!may_access_skb(resolve_prog_type(env->prog))) {
+		verbose(env, "BPF_LD_[ABS|IND] instructions not allowed for this program type\n");
+		return -EINVAL;
+	}
+
+	if (!env->ops->gen_ld_abs) {
+		verbose(env, "bpf verifier is misconfigured\n");
+		return -EINVAL;
+	}
+
+	if (insn->dst_reg != BPF_REG_0 || insn->off != 0 ||
+	    BPF_SIZE(insn->code) == BPF_DW ||
+	    (mode == BPF_ABS && insn->src_reg != BPF_REG_0)) {
+		verbose(env, "BPF_LD_[ABS|IND] uses reserved fields\n");
+		return -EINVAL;
+	}
+
+	/* check whether implicit source operand (register R6) is readable */
+	err = check_reg_arg(env, ctx_reg, SRC_OP);
+	if (err)
+		return err;
+
+	/* Disallow usage of BPF_LD_[ABS|IND] with reference tracking, as
+	 * gen_ld_abs() may terminate the program at runtime, leading to
+	 * reference leak.
+	 */
+	err = check_reference_leak(env);
+	if (err) {
+		verbose(env, "BPF_LD_[ABS|IND] cannot be mixed with socket references\n");
+		return err;
+	}
+
+	if (env->cur_state->active_spin_lock) {
+		verbose(env, "BPF_LD_[ABS|IND] cannot be used inside bpf_spin_lock-ed region\n");
+		return -EINVAL;
+	}
+
+	if (regs[ctx_reg].type != PTR_TO_CTX) {
+		verbose(env,
+			"at the time of BPF_LD_ABS|IND R6 != pointer to skb\n");
+		return -EINVAL;
+	}
+
+	if (mode == BPF_IND) {
+		/* check explicit source operand */
+		err = check_reg_arg(env, insn->src_reg, SRC_OP);
+		if (err)
+			return err;
+	}
+
+	err = check_ctx_reg(env, &regs[ctx_reg], ctx_reg);
+	if (err < 0)
+		return err;
+
+	/* reset caller saved regs to unreadable */
+	for (i = 0; i < CALLER_SAVED_REGS; i++) {
+		mark_reg_not_init(env, regs, caller_saved[i]);
+		check_reg_arg(env, caller_saved[i], DST_OP_NO_MARK);
+	}
+
+	/* mark destination R0 register as readable, since it contains
+	 * the value fetched from the packet.
+	 * Already marked as written above.
+	 */
+	mark_reg_unknown(env, regs, BPF_REG_0);
+	/* ld_abs load up to 32-bit skb data. */
+	regs[BPF_REG_0].subreg_def = env->insn_idx + 1;
+	return 0;
+}
+
+static int check_return_code(struct bpf_verifier_env *env)
+{
+	struct tnum enforce_attach_type_range = tnum_unknown;
+	const struct bpf_prog *prog = env->prog;
+	struct bpf_reg_state *reg;
+	struct tnum range = tnum_range(0, 1);
+	enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
+	int err;
+	const bool is_subprog = env->cur_state->frame[0]->subprogno;
+
+	/* LSM and struct_ops func-ptr's return type could be "void" */
+	if (!is_subprog &&
+	    (prog_type == BPF_PROG_TYPE_STRUCT_OPS ||
+	     prog_type == BPF_PROG_TYPE_LSM) &&
+	    !prog->aux->attach_func_proto->type)
+		return 0;
+
+	/* eBPF calling convetion is such that R0 is used
+	 * to return the value from eBPF program.
+	 * Make sure that it's readable at this time
+	 * of bpf_exit, which means that program wrote
+	 * something into it earlier
+	 */
+	err = check_reg_arg(env, BPF_REG_0, SRC_OP);
+	if (err)
+		return err;
+
+	if (is_pointer_value(env, BPF_REG_0)) {
+		verbose(env, "R0 leaks addr as return value\n");
+		return -EACCES;
+	}
+
+	reg = cur_regs(env) + BPF_REG_0;
+	if (is_subprog) {
+		if (reg->type != SCALAR_VALUE) {
+			verbose(env, "At subprogram exit the register R0 is not a scalar value (%s)\n",
+				reg_type_str[reg->type]);
+			return -EINVAL;
+		}
+		return 0;
+	}
+
+	switch (prog_type) {
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+		if (env->prog->expected_attach_type == BPF_CGROUP_UDP4_RECVMSG ||
+		    env->prog->expected_attach_type == BPF_CGROUP_UDP6_RECVMSG ||
+		    env->prog->expected_attach_type == BPF_CGROUP_INET4_GETPEERNAME ||
+		    env->prog->expected_attach_type == BPF_CGROUP_INET6_GETPEERNAME ||
+		    env->prog->expected_attach_type == BPF_CGROUP_INET4_GETSOCKNAME ||
+		    env->prog->expected_attach_type == BPF_CGROUP_INET6_GETSOCKNAME)
+			range = tnum_range(1, 1);
+		break;
+	case BPF_PROG_TYPE_CGROUP_SKB:
+		if (env->prog->expected_attach_type == BPF_CGROUP_INET_EGRESS) {
+			range = tnum_range(0, 3);
+			enforce_attach_type_range = tnum_range(2, 3);
+		}
+		break;
+	case BPF_PROG_TYPE_CGROUP_SOCK:
+	case BPF_PROG_TYPE_SOCK_OPS:
+	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
+	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+		break;
+	case BPF_PROG_TYPE_RAW_TRACEPOINT:
+		if (!env->prog->aux->attach_btf_id)
+			return 0;
+		range = tnum_const(0);
+		break;
+	case BPF_PROG_TYPE_TRACING:
+		switch (env->prog->expected_attach_type) {
+		case BPF_TRACE_FENTRY:
+		case BPF_TRACE_FEXIT:
+			range = tnum_const(0);
+			break;
+		case BPF_TRACE_RAW_TP:
+		case BPF_MODIFY_RETURN:
+			return 0;
+		case BPF_TRACE_ITER:
+			break;
+		default:
+			return -ENOTSUPP;
+		}
+		break;
+	case BPF_PROG_TYPE_SK_LOOKUP:
+		range = tnum_range(SK_DROP, SK_PASS);
+		break;
+	case BPF_PROG_TYPE_EXT:
+		/* freplace program can return anything as its return value
+		 * depends on the to-be-replaced kernel func or bpf program.
+		 */
+	default:
+		return 0;
+	}
+
+	if (reg->type != SCALAR_VALUE) {
+		verbose(env, "At program exit the register R0 is not a known value (%s)\n",
+			reg_type_str[reg->type]);
+		return -EINVAL;
+	}
+
+	if (!tnum_in(range, reg->var_off)) {
+		char tn_buf[48];
+
+		verbose(env, "At program exit the register R0 ");
+		if (!tnum_is_unknown(reg->var_off)) {
+			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+			verbose(env, "has value %s", tn_buf);
+		} else {
+			verbose(env, "has unknown scalar value");
+		}
+		tnum_strn(tn_buf, sizeof(tn_buf), range);
+		verbose(env, " should have been in %s\n", tn_buf);
+		return -EINVAL;
+	}
+
+	if (!tnum_is_unknown(enforce_attach_type_range) &&
+	    tnum_in(enforce_attach_type_range, reg->var_off))
+		env->prog->enforce_expected_attach_type = 1;
+	return 0;
+}
+
+/* non-recursive DFS pseudo code
+ * 1  procedure DFS-iterative(G,v):
+ * 2      label v as discovered
+ * 3      let S be a stack
+ * 4      S.push(v)
+ * 5      while S is not empty
+ * 6            t <- S.pop()
+ * 7            if t is what we're looking for:
+ * 8                return t
+ * 9            for all edges e in G.adjacentEdges(t) do
+ * 10               if edge e is already labelled
+ * 11                   continue with the next edge
+ * 12               w <- G.adjacentVertex(t,e)
+ * 13               if vertex w is not discovered and not explored
+ * 14                   label e as tree-edge
+ * 15                   label w as discovered
+ * 16                   S.push(w)
+ * 17                   continue at 5
+ * 18               else if vertex w is discovered
+ * 19                   label e as back-edge
+ * 20               else
+ * 21                   // vertex w is explored
+ * 22                   label e as forward- or cross-edge
+ * 23           label t as explored
+ * 24           S.pop()
+ *
+ * convention:
+ * 0x10 - discovered
+ * 0x11 - discovered and fall-through edge labelled
+ * 0x12 - discovered and fall-through and branch edges labelled
+ * 0x20 - explored
+ */
+
+enum {
+	DISCOVERED = 0x10,
+	EXPLORED = 0x20,
+	FALLTHROUGH = 1,
+	BRANCH = 2,
+};
+
+static u32 state_htab_size(struct bpf_verifier_env *env)
+{
+	return env->prog->len;
+}
+
+static struct bpf_verifier_state_list **explored_state(
+					struct bpf_verifier_env *env,
+					int idx)
+{
+	struct bpf_verifier_state *cur = env->cur_state;
+	struct bpf_func_state *state = cur->frame[cur->curframe];
+
+	return &env->explored_states[(idx ^ state->callsite) % state_htab_size(env)];
+}
+
+static void init_explored_state(struct bpf_verifier_env *env, int idx)
+{
+	env->insn_aux_data[idx].prune_point = true;
+}
+
+/* t, w, e - match pseudo-code above:
+ * t - index of current instruction
+ * w - next instruction
+ * e - edge
+ */
+static int push_insn(int t, int w, int e, struct bpf_verifier_env *env,
+		     bool loop_ok)
+{
+	int *insn_stack = env->cfg.insn_stack;
+	int *insn_state = env->cfg.insn_state;
+
+	if (e == FALLTHROUGH && insn_state[t] >= (DISCOVERED | FALLTHROUGH))
+		return 0;
+
+	if (e == BRANCH && insn_state[t] >= (DISCOVERED | BRANCH))
+		return 0;
+
+	if (w < 0 || w >= env->prog->len) {
+		verbose_linfo(env, t, "%d: ", t);
+		verbose(env, "jump out of range from insn %d to %d\n", t, w);
+		return -EINVAL;
+	}
+
+	if (e == BRANCH)
+		/* mark branch target for state pruning */
+		init_explored_state(env, w);
+
+	if (insn_state[w] == 0) {
+		/* tree-edge */
+		insn_state[t] = DISCOVERED | e;
+		insn_state[w] = DISCOVERED;
+		if (env->cfg.cur_stack >= env->prog->len)
+			return -E2BIG;
+		insn_stack[env->cfg.cur_stack++] = w;
+		return 1;
+	} else if ((insn_state[w] & 0xF0) == DISCOVERED) {
+		if (loop_ok && env->bpf_capable)
+			return 0;
+		verbose_linfo(env, t, "%d: ", t);
+		verbose_linfo(env, w, "%d: ", w);
+		verbose(env, "back-edge from insn %d to %d\n", t, w);
+		return -EINVAL;
+	} else if (insn_state[w] == EXPLORED) {
+		/* forward- or cross-edge */
+		insn_state[t] = DISCOVERED | e;
+	} else {
+		verbose(env, "insn state internal bug\n");
+		return -EFAULT;
+	}
+	return 0;
+}
+
+/* non-recursive depth-first-search to detect loops in BPF program
+ * loop == back-edge in directed graph
+ */
+static int check_cfg(struct bpf_verifier_env *env)
+{
+	struct bpf_insn *insns = env->prog->insnsi;
+	int insn_cnt = env->prog->len;
+	int *insn_stack, *insn_state;
+	int ret = 0;
+	int i, t;
+
+	insn_state = env->cfg.insn_state = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
+	if (!insn_state)
+		return -ENOMEM;
+
+	insn_stack = env->cfg.insn_stack = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
+	if (!insn_stack) {
+		kvfree(insn_state);
+		return -ENOMEM;
+	}
+
+	insn_state[0] = DISCOVERED; /* mark 1st insn as discovered */
+	insn_stack[0] = 0; /* 0 is the first instruction */
+	env->cfg.cur_stack = 1;
+
+peek_stack:
+	if (env->cfg.cur_stack == 0)
+		goto check_state;
+	t = insn_stack[env->cfg.cur_stack - 1];
+
+	if (BPF_CLASS(insns[t].code) == BPF_JMP ||
+	    BPF_CLASS(insns[t].code) == BPF_JMP32) {
+		u8 opcode = BPF_OP(insns[t].code);
+
+		if (opcode == BPF_EXIT) {
+			goto mark_explored;
+		} else if (opcode == BPF_CALL) {
+			ret = push_insn(t, t + 1, FALLTHROUGH, env, false);
+			if (ret == 1)
+				goto peek_stack;
+			else if (ret < 0)
+				goto err_free;
+			if (t + 1 < insn_cnt)
+				init_explored_state(env, t + 1);
+			if (insns[t].src_reg == BPF_PSEUDO_CALL) {
+				init_explored_state(env, t);
+				ret = push_insn(t, t + insns[t].imm + 1, BRANCH,
+						env, false);
+				if (ret == 1)
+					goto peek_stack;
+				else if (ret < 0)
+					goto err_free;
+			}
+		} else if (opcode == BPF_JA) {
+			if (BPF_SRC(insns[t].code) != BPF_K) {
+				ret = -EINVAL;
+				goto err_free;
+			}
+			/* unconditional jump with single edge */
+			ret = push_insn(t, t + insns[t].off + 1,
+					FALLTHROUGH, env, true);
+			if (ret == 1)
+				goto peek_stack;
+			else if (ret < 0)
+				goto err_free;
+			/* unconditional jmp is not a good pruning point,
+			 * but it's marked, since backtracking needs
+			 * to record jmp history in is_state_visited().
+			 */
+			init_explored_state(env, t + insns[t].off + 1);
+			/* tell verifier to check for equivalent states
+			 * after every call and jump
+			 */
+			if (t + 1 < insn_cnt)
+				init_explored_state(env, t + 1);
+		} else {
+			/* conditional jump with two edges */
+			init_explored_state(env, t);
+			ret = push_insn(t, t + 1, FALLTHROUGH, env, true);
+			if (ret == 1)
+				goto peek_stack;
+			else if (ret < 0)
+				goto err_free;
+
+			ret = push_insn(t, t + insns[t].off + 1, BRANCH, env, true);
+			if (ret == 1)
+				goto peek_stack;
+			else if (ret < 0)
+				goto err_free;
+		}
+	} else {
+		/* all other non-branch instructions with single
+		 * fall-through edge
+		 */
+		ret = push_insn(t, t + 1, FALLTHROUGH, env, false);
+		if (ret == 1)
+			goto peek_stack;
+		else if (ret < 0)
+			goto err_free;
+	}
+
+mark_explored:
+	insn_state[t] = EXPLORED;
+	if (env->cfg.cur_stack-- <= 0) {
+		verbose(env, "pop stack internal bug\n");
+		ret = -EFAULT;
+		goto err_free;
+	}
+	goto peek_stack;
+
+check_state:
+	for (i = 0; i < insn_cnt; i++) {
+		if (insn_state[i] != EXPLORED) {
+			verbose(env, "unreachable insn %d\n", i);
+			ret = -EINVAL;
+			goto err_free;
+		}
+	}
+	ret = 0; /* cfg looks good */
+
+err_free:
+	kvfree(insn_state);
+	kvfree(insn_stack);
+	env->cfg.insn_state = env->cfg.insn_stack = NULL;
+	return ret;
+}
+
+static int check_abnormal_return(struct bpf_verifier_env *env)
+{
+	int i;
+
+	for (i = 1; i < env->subprog_cnt; i++) {
+		if (env->subprog_info[i].has_ld_abs) {
+			verbose(env, "LD_ABS is not allowed in subprogs without BTF\n");
+			return -EINVAL;
+		}
+		if (env->subprog_info[i].has_tail_call) {
+			verbose(env, "tail_call is not allowed in subprogs without BTF\n");
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+/* The minimum supported BTF func info size */
+#define MIN_BPF_FUNCINFO_SIZE	8
+#define MAX_FUNCINFO_REC_SIZE	252
+
+static int check_btf_func(struct bpf_verifier_env *env,
+			  const union bpf_attr *attr,
+			  union bpf_attr __user *uattr)
+{
+	const struct btf_type *type, *func_proto, *ret_type;
+	u32 i, nfuncs, urec_size, min_size;
+	u32 krec_size = sizeof(struct bpf_func_info);
+	struct bpf_func_info *krecord;
+	struct bpf_func_info_aux *info_aux = NULL;
+	struct bpf_prog *prog;
+	const struct btf *btf;
+	void __user *urecord;
+	u32 prev_offset = 0;
+	bool scalar_return;
+	int ret = -ENOMEM;
+
+	nfuncs = attr->func_info_cnt;
+	if (!nfuncs) {
+		if (check_abnormal_return(env))
+			return -EINVAL;
+		return 0;
+	}
+
+	if (nfuncs != env->subprog_cnt) {
+		verbose(env, "number of funcs in func_info doesn't match number of subprogs\n");
+		return -EINVAL;
+	}
+
+	urec_size = attr->func_info_rec_size;
+	if (urec_size < MIN_BPF_FUNCINFO_SIZE ||
+	    urec_size > MAX_FUNCINFO_REC_SIZE ||
+	    urec_size % sizeof(u32)) {
+		verbose(env, "invalid func info rec size %u\n", urec_size);
+		return -EINVAL;
+	}
+
+	prog = env->prog;
+	btf = prog->aux->btf;
+
+	urecord = u64_to_user_ptr(attr->func_info);
+	min_size = min_t(u32, krec_size, urec_size);
+
+	krecord = kvcalloc(nfuncs, krec_size, GFP_KERNEL | __GFP_NOWARN);
+	if (!krecord)
+		return -ENOMEM;
+	info_aux = kcalloc(nfuncs, sizeof(*info_aux), GFP_KERNEL | __GFP_NOWARN);
+	if (!info_aux)
+		goto err_free;
+
+	for (i = 0; i < nfuncs; i++) {
+		ret = bpf_check_uarg_tail_zero(urecord, krec_size, urec_size);
+		if (ret) {
+			if (ret == -E2BIG) {
+				verbose(env, "nonzero tailing record in func info");
+				/* set the size kernel expects so loader can zero
+				 * out the rest of the record.
+				 */
+				if (put_user(min_size, &uattr->func_info_rec_size))
+					ret = -EFAULT;
+			}
+			goto err_free;
+		}
+
+		if (copy_from_user(&krecord[i], urecord, min_size)) {
+			ret = -EFAULT;
+			goto err_free;
+		}
+
+		/* check insn_off */
+		ret = -EINVAL;
+		if (i == 0) {
+			if (krecord[i].insn_off) {
+				verbose(env,
+					"nonzero insn_off %u for the first func info record",
+					krecord[i].insn_off);
+				goto err_free;
+			}
+		} else if (krecord[i].insn_off <= prev_offset) {
+			verbose(env,
+				"same or smaller insn offset (%u) than previous func info record (%u)",
+				krecord[i].insn_off, prev_offset);
+			goto err_free;
+		}
+
+		if (env->subprog_info[i].start != krecord[i].insn_off) {
+			verbose(env, "func_info BTF section doesn't match subprog layout in BPF program\n");
+			goto err_free;
+		}
+
+		/* check type_id */
+		type = btf_type_by_id(btf, krecord[i].type_id);
+		if (!type || !btf_type_is_func(type)) {
+			verbose(env, "invalid type id %d in func info",
+				krecord[i].type_id);
+			goto err_free;
+		}
+		info_aux[i].linkage = BTF_INFO_VLEN(type->info);
+
+		func_proto = btf_type_by_id(btf, type->type);
+		if (unlikely(!func_proto || !btf_type_is_func_proto(func_proto)))
+			/* btf_func_check() already verified it during BTF load */
+			goto err_free;
+		ret_type = btf_type_skip_modifiers(btf, func_proto->type, NULL);
+		scalar_return =
+			btf_type_is_small_int(ret_type) || btf_type_is_enum(ret_type);
+		if (i && !scalar_return && env->subprog_info[i].has_ld_abs) {
+			verbose(env, "LD_ABS is only allowed in functions that return 'int'.\n");
+			goto err_free;
+		}
+		if (i && !scalar_return && env->subprog_info[i].has_tail_call) {
+			verbose(env, "tail_call is only allowed in functions that return 'int'.\n");
+			goto err_free;
+		}
+
+		prev_offset = krecord[i].insn_off;
+		urecord += urec_size;
+	}
+
+	prog->aux->func_info = krecord;
+	prog->aux->func_info_cnt = nfuncs;
+	prog->aux->func_info_aux = info_aux;
+	return 0;
+
+err_free:
+	kvfree(krecord);
+	kfree(info_aux);
+	return ret;
+}
+
+static void adjust_btf_func(struct bpf_verifier_env *env)
+{
+	struct bpf_prog_aux *aux = env->prog->aux;
+	int i;
+
+	if (!aux->func_info)
+		return;
+
+	for (i = 0; i < env->subprog_cnt; i++)
+		aux->func_info[i].insn_off = env->subprog_info[i].start;
+}
+
+#define MIN_BPF_LINEINFO_SIZE	(offsetof(struct bpf_line_info, line_col) + \
+		sizeof(((struct bpf_line_info *)(0))->line_col))
+#define MAX_LINEINFO_REC_SIZE	MAX_FUNCINFO_REC_SIZE
+
+static int check_btf_line(struct bpf_verifier_env *env,
+			  const union bpf_attr *attr,
+			  union bpf_attr __user *uattr)
+{
+	u32 i, s, nr_linfo, ncopy, expected_size, rec_size, prev_offset = 0;
+	struct bpf_subprog_info *sub;
+	struct bpf_line_info *linfo;
+	struct bpf_prog *prog;
+	const struct btf *btf;
+	void __user *ulinfo;
+	int err;
+
+	nr_linfo = attr->line_info_cnt;
+	if (!nr_linfo)
+		return 0;
+	if (nr_linfo > INT_MAX / sizeof(struct bpf_line_info))
+		return -EINVAL;
+
+	rec_size = attr->line_info_rec_size;
+	if (rec_size < MIN_BPF_LINEINFO_SIZE ||
+	    rec_size > MAX_LINEINFO_REC_SIZE ||
+	    rec_size & (sizeof(u32) - 1))
+		return -EINVAL;
+
+	/* Need to zero it in case the userspace may
+	 * pass in a smaller bpf_line_info object.
+	 */
+	linfo = kvcalloc(nr_linfo, sizeof(struct bpf_line_info),
+			 GFP_KERNEL | __GFP_NOWARN);
+	if (!linfo)
+		return -ENOMEM;
+
+	prog = env->prog;
+	btf = prog->aux->btf;
+
+	s = 0;
+	sub = env->subprog_info;
+	ulinfo = u64_to_user_ptr(attr->line_info);
+	expected_size = sizeof(struct bpf_line_info);
+	ncopy = min_t(u32, expected_size, rec_size);
+	for (i = 0; i < nr_linfo; i++) {
+		err = bpf_check_uarg_tail_zero(ulinfo, expected_size, rec_size);
+		if (err) {
+			if (err == -E2BIG) {
+				verbose(env, "nonzero tailing record in line_info");
+				if (put_user(expected_size,
+					     &uattr->line_info_rec_size))
+					err = -EFAULT;
+			}
+			goto err_free;
+		}
+
+		if (copy_from_user(&linfo[i], ulinfo, ncopy)) {
+			err = -EFAULT;
+			goto err_free;
+		}
+
+		/*
+		 * Check insn_off to ensure
+		 * 1) strictly increasing AND
+		 * 2) bounded by prog->len
+		 *
+		 * The linfo[0].insn_off == 0 check logically falls into
+		 * the later "missing bpf_line_info for func..." case
+		 * because the first linfo[0].insn_off must be the
+		 * first sub also and the first sub must have
+		 * subprog_info[0].start == 0.
+		 */
+		if ((i && linfo[i].insn_off <= prev_offset) ||
+		    linfo[i].insn_off >= prog->len) {
+			verbose(env, "Invalid line_info[%u].insn_off:%u (prev_offset:%u prog->len:%u)\n",
+				i, linfo[i].insn_off, prev_offset,
+				prog->len);
+			err = -EINVAL;
+			goto err_free;
+		}
+
+		if (!prog->insnsi[linfo[i].insn_off].code) {
+			verbose(env,
+				"Invalid insn code at line_info[%u].insn_off\n",
+				i);
+			err = -EINVAL;
+			goto err_free;
+		}
+
+		if (!btf_name_by_offset(btf, linfo[i].line_off) ||
+		    !btf_name_by_offset(btf, linfo[i].file_name_off)) {
+			verbose(env, "Invalid line_info[%u].line_off or .file_name_off\n", i);
+			err = -EINVAL;
+			goto err_free;
+		}
+
+		if (s != env->subprog_cnt) {
+			if (linfo[i].insn_off == sub[s].start) {
+				sub[s].linfo_idx = i;
+				s++;
+			} else if (sub[s].start < linfo[i].insn_off) {
+				verbose(env, "missing bpf_line_info for func#%u\n", s);
+				err = -EINVAL;
+				goto err_free;
+			}
+		}
+
+		prev_offset = linfo[i].insn_off;
+		ulinfo += rec_size;
+	}
+
+	if (s != env->subprog_cnt) {
+		verbose(env, "missing bpf_line_info for %u funcs starting from func#%u\n",
+			env->subprog_cnt - s, s);
+		err = -EINVAL;
+		goto err_free;
+	}
+
+	prog->aux->linfo = linfo;
+	prog->aux->nr_linfo = nr_linfo;
+
+	return 0;
+
+err_free:
+	kvfree(linfo);
+	return err;
+}
+
+static int check_btf_info(struct bpf_verifier_env *env,
+			  const union bpf_attr *attr,
+			  union bpf_attr __user *uattr)
+{
+	struct btf *btf;
+	int err;
+
+	if (!attr->func_info_cnt && !attr->line_info_cnt) {
+		if (check_abnormal_return(env))
+			return -EINVAL;
+		return 0;
+	}
+
+	btf = btf_get_by_fd(attr->prog_btf_fd);
+	if (IS_ERR(btf))
+		return PTR_ERR(btf);
+	env->prog->aux->btf = btf;
+
+	err = check_btf_func(env, attr, uattr);
+	if (err)
+		return err;
+
+	err = check_btf_line(env, attr, uattr);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+/* check %cur's range satisfies %old's */
+static bool range_within(struct bpf_reg_state *old,
+			 struct bpf_reg_state *cur)
+{
+	return old->umin_value <= cur->umin_value &&
+	       old->umax_value >= cur->umax_value &&
+	       old->smin_value <= cur->smin_value &&
+	       old->smax_value >= cur->smax_value &&
+	       old->u32_min_value <= cur->u32_min_value &&
+	       old->u32_max_value >= cur->u32_max_value &&
+	       old->s32_min_value <= cur->s32_min_value &&
+	       old->s32_max_value >= cur->s32_max_value;
+}
+
+/* If in the old state two registers had the same id, then they need to have
+ * the same id in the new state as well.  But that id could be different from
+ * the old state, so we need to track the mapping from old to new ids.
+ * Once we have seen that, say, a reg with old id 5 had new id 9, any subsequent
+ * regs with old id 5 must also have new id 9 for the new state to be safe.  But
+ * regs with a different old id could still have new id 9, we don't care about
+ * that.
+ * So we look through our idmap to see if this old id has been seen before.  If
+ * so, we require the new id to match; otherwise, we add the id pair to the map.
+ */
+static bool check_ids(u32 old_id, u32 cur_id, struct bpf_id_pair *idmap)
+{
+	unsigned int i;
+
+	for (i = 0; i < BPF_ID_MAP_SIZE; i++) {
+		if (!idmap[i].old) {
+			/* Reached an empty slot; haven't seen this id before */
+			idmap[i].old = old_id;
+			idmap[i].cur = cur_id;
+			return true;
+		}
+		if (idmap[i].old == old_id)
+			return idmap[i].cur == cur_id;
+	}
+	/* We ran out of idmap slots, which should be impossible */
+	WARN_ON_ONCE(1);
+	return false;
+}
+
+static void clean_func_state(struct bpf_verifier_env *env,
+			     struct bpf_func_state *st)
+{
+	enum bpf_reg_liveness live;
+	int i, j;
+
+	for (i = 0; i < BPF_REG_FP; i++) {
+		live = st->regs[i].live;
+		/* liveness must not touch this register anymore */
+		st->regs[i].live |= REG_LIVE_DONE;
+		if (!(live & REG_LIVE_READ))
+			/* since the register is unused, clear its state
+			 * to make further comparison simpler
+			 */
+			__mark_reg_not_init(env, &st->regs[i]);
+	}
+
+	for (i = 0; i < st->allocated_stack / BPF_REG_SIZE; i++) {
+		live = st->stack[i].spilled_ptr.live;
+		/* liveness must not touch this stack slot anymore */
+		st->stack[i].spilled_ptr.live |= REG_LIVE_DONE;
+		if (!(live & REG_LIVE_READ)) {
+			__mark_reg_not_init(env, &st->stack[i].spilled_ptr);
+			for (j = 0; j < BPF_REG_SIZE; j++)
+				st->stack[i].slot_type[j] = STACK_INVALID;
+		}
+	}
+}
+
+static void clean_verifier_state(struct bpf_verifier_env *env,
+				 struct bpf_verifier_state *st)
+{
+	int i;
+
+	if (st->frame[0]->regs[0].live & REG_LIVE_DONE)
+		/* all regs in this state in all frames were already marked */
+		return;
+
+	for (i = 0; i <= st->curframe; i++)
+		clean_func_state(env, st->frame[i]);
+}
+
+/* the parentage chains form a tree.
+ * the verifier states are added to state lists at given insn and
+ * pushed into state stack for future exploration.
+ * when the verifier reaches bpf_exit insn some of the verifer states
+ * stored in the state lists have their final liveness state already,
+ * but a lot of states will get revised from liveness point of view when
+ * the verifier explores other branches.
+ * Example:
+ * 1: r0 = 1
+ * 2: if r1 == 100 goto pc+1
+ * 3: r0 = 2
+ * 4: exit
+ * when the verifier reaches exit insn the register r0 in the state list of
+ * insn 2 will be seen as !REG_LIVE_READ. Then the verifier pops the other_branch
+ * of insn 2 and goes exploring further. At the insn 4 it will walk the
+ * parentage chain from insn 4 into insn 2 and will mark r0 as REG_LIVE_READ.
+ *
+ * Since the verifier pushes the branch states as it sees them while exploring
+ * the program the condition of walking the branch instruction for the second
+ * time means that all states below this branch were already explored and
+ * their final liveness markes are already propagated.
+ * Hence when the verifier completes the search of state list in is_state_visited()
+ * we can call this clean_live_states() function to mark all liveness states
+ * as REG_LIVE_DONE to indicate that 'parent' pointers of 'struct bpf_reg_state'
+ * will not be used.
+ * This function also clears the registers and stack for states that !READ
+ * to simplify state merging.
+ *
+ * Important note here that walking the same branch instruction in the callee
+ * doesn't meant that the states are DONE. The verifier has to compare
+ * the callsites
+ */
+static void clean_live_states(struct bpf_verifier_env *env, int insn,
+			      struct bpf_verifier_state *cur)
+{
+	struct bpf_verifier_state_list *sl;
+	int i;
+
+	sl = *explored_state(env, insn);
+	while (sl) {
+		if (sl->state.branches)
+			goto next;
+		if (sl->state.insn_idx != insn ||
+		    sl->state.curframe != cur->curframe)
+			goto next;
+		for (i = 0; i <= cur->curframe; i++)
+			if (sl->state.frame[i]->callsite != cur->frame[i]->callsite)
+				goto next;
+		clean_verifier_state(env, &sl->state);
+next:
+		sl = sl->next;
+	}
+}
+
+/* Returns true if (rold safe implies rcur safe) */
+static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold,
+		    struct bpf_reg_state *rcur, struct bpf_id_pair *idmap)
+{
+	bool equal;
+
+	if (!(rold->live & REG_LIVE_READ))
+		/* explored state didn't use this */
+		return true;
+
+	equal = memcmp(rold, rcur, offsetof(struct bpf_reg_state, parent)) == 0;
+
+	if (rold->type == PTR_TO_STACK)
+		/* two stack pointers are equal only if they're pointing to
+		 * the same stack frame, since fp-8 in foo != fp-8 in bar
+		 */
+		return equal && rold->frameno == rcur->frameno;
+
+	if (equal)
+		return true;
+
+	if (rold->type == NOT_INIT)
+		/* explored state can't have used this */
+		return true;
+	if (rcur->type == NOT_INIT)
+		return false;
+	switch (rold->type) {
+	case SCALAR_VALUE:
+		if (env->explore_alu_limits)
+			return false;
+		if (rcur->type == SCALAR_VALUE) {
+			if (!rold->precise)
+				return true;
+			/* new val must satisfy old val knowledge */
+			return range_within(rold, rcur) &&
+			       tnum_in(rold->var_off, rcur->var_off);
+		} else {
+			/* We're trying to use a pointer in place of a scalar.
+			 * Even if the scalar was unbounded, this could lead to
+			 * pointer leaks because scalars are allowed to leak
+			 * while pointers are not. We could make this safe in
+			 * special cases if root is calling us, but it's
+			 * probably not worth the hassle.
+			 */
+			return false;
+		}
+	case PTR_TO_MAP_VALUE:
+		/* If the new min/max/var_off satisfy the old ones and
+		 * everything else matches, we are OK.
+		 * 'id' is not compared, since it's only used for maps with
+		 * bpf_spin_lock inside map element and in such cases if
+		 * the rest of the prog is valid for one map element then
+		 * it's valid for all map elements regardless of the key
+		 * used in bpf_map_lookup()
+		 */
+		return memcmp(rold, rcur, offsetof(struct bpf_reg_state, id)) == 0 &&
+		       range_within(rold, rcur) &&
+		       tnum_in(rold->var_off, rcur->var_off);
+	case PTR_TO_MAP_VALUE_OR_NULL:
+		/* a PTR_TO_MAP_VALUE could be safe to use as a
+		 * PTR_TO_MAP_VALUE_OR_NULL into the same map.
+		 * However, if the old PTR_TO_MAP_VALUE_OR_NULL then got NULL-
+		 * checked, doing so could have affected others with the same
+		 * id, and we can't check for that because we lost the id when
+		 * we converted to a PTR_TO_MAP_VALUE.
+		 */
+		if (rcur->type != PTR_TO_MAP_VALUE_OR_NULL)
+			return false;
+		if (memcmp(rold, rcur, offsetof(struct bpf_reg_state, id)))
+			return false;
+		/* Check our ids match any regs they're supposed to */
+		return check_ids(rold->id, rcur->id, idmap);
+	case PTR_TO_PACKET_META:
+	case PTR_TO_PACKET:
+		if (rcur->type != rold->type)
+			return false;
+		/* We must have at least as much range as the old ptr
+		 * did, so that any accesses which were safe before are
+		 * still safe.  This is true even if old range < old off,
+		 * since someone could have accessed through (ptr - k), or
+		 * even done ptr -= k in a register, to get a safe access.
+		 */
+		if (rold->range > rcur->range)
+			return false;
+		/* If the offsets don't match, we can't trust our alignment;
+		 * nor can we be sure that we won't fall out of range.
+		 */
+		if (rold->off != rcur->off)
+			return false;
+		/* id relations must be preserved */
+		if (rold->id && !check_ids(rold->id, rcur->id, idmap))
+			return false;
+		/* new val must satisfy old val knowledge */
+		return range_within(rold, rcur) &&
+		       tnum_in(rold->var_off, rcur->var_off);
+	case PTR_TO_CTX:
+	case CONST_PTR_TO_MAP:
+	case PTR_TO_PACKET_END:
+	case PTR_TO_FLOW_KEYS:
+	case PTR_TO_SOCKET:
+	case PTR_TO_SOCKET_OR_NULL:
+	case PTR_TO_SOCK_COMMON:
+	case PTR_TO_SOCK_COMMON_OR_NULL:
+	case PTR_TO_TCP_SOCK:
+	case PTR_TO_TCP_SOCK_OR_NULL:
+	case PTR_TO_XDP_SOCK:
+		/* Only valid matches are exact, which memcmp() above
+		 * would have accepted
+		 */
+	default:
+		/* Don't know what's going on, just say it's not safe */
+		return false;
+	}
+
+	/* Shouldn't get here; if we do, say it's not safe */
+	WARN_ON_ONCE(1);
+	return false;
+}
+
+static bool stacksafe(struct bpf_verifier_env *env, struct bpf_func_state *old,
+		      struct bpf_func_state *cur, struct bpf_id_pair *idmap)
+{
+	int i, spi;
+
+	/* walk slots of the explored stack and ignore any additional
+	 * slots in the current stack, since explored(safe) state
+	 * didn't use them
+	 */
+	for (i = 0; i < old->allocated_stack; i++) {
+		spi = i / BPF_REG_SIZE;
+
+		if (!(old->stack[spi].spilled_ptr.live & REG_LIVE_READ)) {
+			i += BPF_REG_SIZE - 1;
+			/* explored state didn't use this */
+			continue;
+		}
+
+		if (old->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_INVALID)
+			continue;
+
+		/* explored stack has more populated slots than current stack
+		 * and these slots were used
+		 */
+		if (i >= cur->allocated_stack)
+			return false;
+
+		/* if old state was safe with misc data in the stack
+		 * it will be safe with zero-initialized stack.
+		 * The opposite is not true
+		 */
+		if (old->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_MISC &&
+		    cur->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_ZERO)
+			continue;
+		if (old->stack[spi].slot_type[i % BPF_REG_SIZE] !=
+		    cur->stack[spi].slot_type[i % BPF_REG_SIZE])
+			/* Ex: old explored (safe) state has STACK_SPILL in
+			 * this stack slot, but current has STACK_MISC ->
+			 * this verifier states are not equivalent,
+			 * return false to continue verification of this path
+			 */
+			return false;
+		if (i % BPF_REG_SIZE != BPF_REG_SIZE - 1)
+			continue;
+		if (!is_spilled_reg(&old->stack[spi]))
+			continue;
+		if (!regsafe(env, &old->stack[spi].spilled_ptr,
+			     &cur->stack[spi].spilled_ptr, idmap))
+			/* when explored and current stack slot are both storing
+			 * spilled registers, check that stored pointers types
+			 * are the same as well.
+			 * Ex: explored safe path could have stored
+			 * (bpf_reg_state) {.type = PTR_TO_STACK, .off = -8}
+			 * but current path has stored:
+			 * (bpf_reg_state) {.type = PTR_TO_STACK, .off = -16}
+			 * such verifier states are not equivalent.
+			 * return false to continue verification of this path
+			 */
+			return false;
+	}
+	return true;
+}
+
+static bool refsafe(struct bpf_func_state *old, struct bpf_func_state *cur)
+{
+	if (old->acquired_refs != cur->acquired_refs)
+		return false;
+	return !memcmp(old->refs, cur->refs,
+		       sizeof(*old->refs) * old->acquired_refs);
+}
+
+/* compare two verifier states
+ *
+ * all states stored in state_list are known to be valid, since
+ * verifier reached 'bpf_exit' instruction through them
+ *
+ * this function is called when verifier exploring different branches of
+ * execution popped from the state stack. If it sees an old state that has
+ * more strict register state and more strict stack state then this execution
+ * branch doesn't need to be explored further, since verifier already
+ * concluded that more strict state leads to valid finish.
+ *
+ * Therefore two states are equivalent if register state is more conservative
+ * and explored stack state is more conservative than the current one.
+ * Example:
+ *       explored                   current
+ * (slot1=INV slot2=MISC) == (slot1=MISC slot2=MISC)
+ * (slot1=MISC slot2=MISC) != (slot1=INV slot2=MISC)
+ *
+ * In other words if current stack state (one being explored) has more
+ * valid slots than old one that already passed validation, it means
+ * the verifier can stop exploring and conclude that current state is valid too
+ *
+ * Similarly with registers. If explored state has register type as invalid
+ * whereas register type in current state is meaningful, it means that
+ * the current state will reach 'bpf_exit' instruction safely
+ */
+static bool func_states_equal(struct bpf_verifier_env *env, struct bpf_func_state *old,
+			      struct bpf_func_state *cur)
+{
+	int i;
+
+	memset(env->idmap_scratch, 0, sizeof(env->idmap_scratch));
+	for (i = 0; i < MAX_BPF_REG; i++)
+		if (!regsafe(env, &old->regs[i], &cur->regs[i],
+			     env->idmap_scratch))
+			return false;
+
+	if (!stacksafe(env, old, cur, env->idmap_scratch))
+		return false;
+
+	if (!refsafe(old, cur))
+		return false;
+
+	return true;
+}
+
+static bool states_equal(struct bpf_verifier_env *env,
+			 struct bpf_verifier_state *old,
+			 struct bpf_verifier_state *cur)
+{
+	int i;
+
+	if (old->curframe != cur->curframe)
+		return false;
+
+	/* Verification state from speculative execution simulation
+	 * must never prune a non-speculative execution one.
+	 */
+	if (old->speculative && !cur->speculative)
+		return false;
+
+	if (old->active_spin_lock != cur->active_spin_lock)
+		return false;
+
+	/* for states to be equal callsites have to be the same
+	 * and all frame states need to be equivalent
+	 */
+	for (i = 0; i <= old->curframe; i++) {
+		if (old->frame[i]->callsite != cur->frame[i]->callsite)
+			return false;
+		if (!func_states_equal(env, old->frame[i], cur->frame[i]))
+			return false;
+	}
+	return true;
+}
+
+/* Return 0 if no propagation happened. Return negative error code if error
+ * happened. Otherwise, return the propagated bit.
+ */
+static int propagate_liveness_reg(struct bpf_verifier_env *env,
+				  struct bpf_reg_state *reg,
+				  struct bpf_reg_state *parent_reg)
+{
+	u8 parent_flag = parent_reg->live & REG_LIVE_READ;
+	u8 flag = reg->live & REG_LIVE_READ;
+	int err;
+
+	/* When comes here, read flags of PARENT_REG or REG could be any of
+	 * REG_LIVE_READ64, REG_LIVE_READ32, REG_LIVE_NONE. There is no need
+	 * of propagation if PARENT_REG has strongest REG_LIVE_READ64.
+	 */
+	if (parent_flag == REG_LIVE_READ64 ||
+	    /* Or if there is no read flag from REG. */
+	    !flag ||
+	    /* Or if the read flag from REG is the same as PARENT_REG. */
+	    parent_flag == flag)
+		return 0;
+
+	err = mark_reg_read(env, reg, parent_reg, flag);
+	if (err)
+		return err;
+
+	return flag;
+}
+
+/* A write screens off any subsequent reads; but write marks come from the
+ * straight-line code between a state and its parent.  When we arrive at an
+ * equivalent state (jump target or such) we didn't arrive by the straight-line
+ * code, so read marks in the state must propagate to the parent regardless
+ * of the state's write marks. That's what 'parent == state->parent' comparison
+ * in mark_reg_read() is for.
+ */
+static int propagate_liveness(struct bpf_verifier_env *env,
+			      const struct bpf_verifier_state *vstate,
+			      struct bpf_verifier_state *vparent)
+{
+	struct bpf_reg_state *state_reg, *parent_reg;
+	struct bpf_func_state *state, *parent;
+	int i, frame, err = 0;
+
+	if (vparent->curframe != vstate->curframe) {
+		WARN(1, "propagate_live: parent frame %d current frame %d\n",
+		     vparent->curframe, vstate->curframe);
+		return -EFAULT;
+	}
+	/* Propagate read liveness of registers... */
+	BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG);
+	for (frame = 0; frame <= vstate->curframe; frame++) {
+		parent = vparent->frame[frame];
+		state = vstate->frame[frame];
+		parent_reg = parent->regs;
+		state_reg = state->regs;
+		/* We don't need to worry about FP liveness, it's read-only */
+		for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) {
+			err = propagate_liveness_reg(env, &state_reg[i],
+						     &parent_reg[i]);
+			if (err < 0)
+				return err;
+			if (err == REG_LIVE_READ64)
+				mark_insn_zext(env, &parent_reg[i]);
+		}
+
+		/* Propagate stack slots. */
+		for (i = 0; i < state->allocated_stack / BPF_REG_SIZE &&
+			    i < parent->allocated_stack / BPF_REG_SIZE; i++) {
+			parent_reg = &parent->stack[i].spilled_ptr;
+			state_reg = &state->stack[i].spilled_ptr;
+			err = propagate_liveness_reg(env, state_reg,
+						     parent_reg);
+			if (err < 0)
+				return err;
+		}
+	}
+	return 0;
+}
+
+/* find precise scalars in the previous equivalent state and
+ * propagate them into the current state
+ */
+static int propagate_precision(struct bpf_verifier_env *env,
+			       const struct bpf_verifier_state *old)
+{
+	struct bpf_reg_state *state_reg;
+	struct bpf_func_state *state;
+	int i, err = 0, fr;
+
+	for (fr = old->curframe; fr >= 0; fr--) {
+		state = old->frame[fr];
+		state_reg = state->regs;
+		for (i = 0; i < BPF_REG_FP; i++, state_reg++) {
+			if (state_reg->type != SCALAR_VALUE ||
+			    !state_reg->precise ||
+			    !(state_reg->live & REG_LIVE_READ))
+				continue;
+			if (env->log.level & BPF_LOG_LEVEL2)
+				verbose(env, "frame %d: propagating r%d\n", fr, i);
+			err = mark_chain_precision_frame(env, fr, i);
+			if (err < 0)
+				return err;
+		}
+
+		for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
+			if (!is_spilled_reg(&state->stack[i]))
+				continue;
+			state_reg = &state->stack[i].spilled_ptr;
+			if (state_reg->type != SCALAR_VALUE ||
+			    !state_reg->precise ||
+			    !(state_reg->live & REG_LIVE_READ))
+				continue;
+			if (env->log.level & BPF_LOG_LEVEL2)
+				verbose(env, "frame %d: propagating fp%d\n",
+					fr, (-i - 1) * BPF_REG_SIZE);
+			err = mark_chain_precision_stack_frame(env, fr, i);
+			if (err < 0)
+				return err;
+		}
+	}
+	return 0;
+}
+
+static bool states_maybe_looping(struct bpf_verifier_state *old,
+				 struct bpf_verifier_state *cur)
+{
+	struct bpf_func_state *fold, *fcur;
+	int i, fr = cur->curframe;
+
+	if (old->curframe != fr)
+		return false;
+
+	fold = old->frame[fr];
+	fcur = cur->frame[fr];
+	for (i = 0; i < MAX_BPF_REG; i++)
+		if (memcmp(&fold->regs[i], &fcur->regs[i],
+			   offsetof(struct bpf_reg_state, parent)))
+			return false;
+	return true;
+}
+
+
+static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
+{
+	struct bpf_verifier_state_list *new_sl;
+	struct bpf_verifier_state_list *sl, **pprev;
+	struct bpf_verifier_state *cur = env->cur_state, *new;
+	int i, j, err, states_cnt = 0;
+	bool add_new_state = env->test_state_freq ? true : false;
+
+	cur->last_insn_idx = env->prev_insn_idx;
+	if (!env->insn_aux_data[insn_idx].prune_point)
+		/* this 'insn_idx' instruction wasn't marked, so we will not
+		 * be doing state search here
+		 */
+		return 0;
+
+	/* bpf progs typically have pruning point every 4 instructions
+	 * http://vger.kernel.org/bpfconf2019.html#session-1
+	 * Do not add new state for future pruning if the verifier hasn't seen
+	 * at least 2 jumps and at least 8 instructions.
+	 * This heuristics helps decrease 'total_states' and 'peak_states' metric.
+	 * In tests that amounts to up to 50% reduction into total verifier
+	 * memory consumption and 20% verifier time speedup.
+	 */
+	if (env->jmps_processed - env->prev_jmps_processed >= 2 &&
+	    env->insn_processed - env->prev_insn_processed >= 8)
+		add_new_state = true;
+
+	pprev = explored_state(env, insn_idx);
+	sl = *pprev;
+
+	clean_live_states(env, insn_idx, cur);
+
+	while (sl) {
+		states_cnt++;
+		if (sl->state.insn_idx != insn_idx)
+			goto next;
+		if (sl->state.branches) {
+			if (states_maybe_looping(&sl->state, cur) &&
+			    states_equal(env, &sl->state, cur)) {
+				verbose_linfo(env, insn_idx, "; ");
+				verbose(env, "infinite loop detected at insn %d\n", insn_idx);
+				return -EINVAL;
+			}
+			/* if the verifier is processing a loop, avoid adding new state
+			 * too often, since different loop iterations have distinct
+			 * states and may not help future pruning.
+			 * This threshold shouldn't be too low to make sure that
+			 * a loop with large bound will be rejected quickly.
+			 * The most abusive loop will be:
+			 * r1 += 1
+			 * if r1 < 1000000 goto pc-2
+			 * 1M insn_procssed limit / 100 == 10k peak states.
+			 * This threshold shouldn't be too high either, since states
+			 * at the end of the loop are likely to be useful in pruning.
+			 */
+			if (env->jmps_processed - env->prev_jmps_processed < 20 &&
+			    env->insn_processed - env->prev_insn_processed < 100)
+				add_new_state = false;
+			goto miss;
+		}
+		if (states_equal(env, &sl->state, cur)) {
+			sl->hit_cnt++;
+			/* reached equivalent register/stack state,
+			 * prune the search.
+			 * Registers read by the continuation are read by us.
+			 * If we have any write marks in env->cur_state, they
+			 * will prevent corresponding reads in the continuation
+			 * from reaching our parent (an explored_state).  Our
+			 * own state will get the read marks recorded, but
+			 * they'll be immediately forgotten as we're pruning
+			 * this state and will pop a new one.
+			 */
+			err = propagate_liveness(env, &sl->state, cur);
+
+			/* if previous state reached the exit with precision and
+			 * current state is equivalent to it (except precsion marks)
+			 * the precision needs to be propagated back in
+			 * the current state.
+			 */
+			err = err ? : push_jmp_history(env, cur);
+			err = err ? : propagate_precision(env, &sl->state);
+			if (err)
+				return err;
+			return 1;
+		}
+miss:
+		/* when new state is not going to be added do not increase miss count.
+		 * Otherwise several loop iterations will remove the state
+		 * recorded earlier. The goal of these heuristics is to have
+		 * states from some iterations of the loop (some in the beginning
+		 * and some at the end) to help pruning.
+		 */
+		if (add_new_state)
+			sl->miss_cnt++;
+		/* heuristic to determine whether this state is beneficial
+		 * to keep checking from state equivalence point of view.
+		 * Higher numbers increase max_states_per_insn and verification time,
+		 * but do not meaningfully decrease insn_processed.
+		 */
+		if (sl->miss_cnt > sl->hit_cnt * 3 + 3) {
+			/* the state is unlikely to be useful. Remove it to
+			 * speed up verification
+			 */
+			*pprev = sl->next;
+			if (sl->state.frame[0]->regs[0].live & REG_LIVE_DONE) {
+				u32 br = sl->state.branches;
+
+				WARN_ONCE(br,
+					  "BUG live_done but branches_to_explore %d\n",
+					  br);
+				free_verifier_state(&sl->state, false);
+				kfree(sl);
+				env->peak_states--;
+			} else {
+				/* cannot free this state, since parentage chain may
+				 * walk it later. Add it for free_list instead to
+				 * be freed at the end of verification
+				 */
+				sl->next = env->free_list;
+				env->free_list = sl;
+			}
+			sl = *pprev;
+			continue;
+		}
+next:
+		pprev = &sl->next;
+		sl = *pprev;
+	}
+
+	if (env->max_states_per_insn < states_cnt)
+		env->max_states_per_insn = states_cnt;
+
+	if (!env->bpf_capable && states_cnt > BPF_COMPLEXITY_LIMIT_STATES)
+		return push_jmp_history(env, cur);
+
+	if (!add_new_state)
+		return push_jmp_history(env, cur);
+
+	/* There were no equivalent states, remember the current one.
+	 * Technically the current state is not proven to be safe yet,
+	 * but it will either reach outer most bpf_exit (which means it's safe)
+	 * or it will be rejected. When there are no loops the verifier won't be
+	 * seeing this tuple (frame[0].callsite, frame[1].callsite, .. insn_idx)
+	 * again on the way to bpf_exit.
+	 * When looping the sl->state.branches will be > 0 and this state
+	 * will not be considered for equivalence until branches == 0.
+	 */
+	new_sl = kzalloc(sizeof(struct bpf_verifier_state_list), GFP_KERNEL);
+	if (!new_sl)
+		return -ENOMEM;
+	env->total_states++;
+	env->peak_states++;
+	env->prev_jmps_processed = env->jmps_processed;
+	env->prev_insn_processed = env->insn_processed;
+
+	/* forget precise markings we inherited, see __mark_chain_precision */
+	if (env->bpf_capable)
+		mark_all_scalars_imprecise(env, cur);
+
+	/* add new state to the head of linked list */
+	new = &new_sl->state;
+	err = copy_verifier_state(new, cur);
+	if (err) {
+		free_verifier_state(new, false);
+		kfree(new_sl);
+		return err;
+	}
+	new->insn_idx = insn_idx;
+	WARN_ONCE(new->branches != 1,
+		  "BUG is_state_visited:branches_to_explore=%d insn %d\n", new->branches, insn_idx);
+
+	cur->parent = new;
+	cur->first_insn_idx = insn_idx;
+	clear_jmp_history(cur);
+	new_sl->next = *explored_state(env, insn_idx);
+	*explored_state(env, insn_idx) = new_sl;
+	/* connect new state to parentage chain. Current frame needs all
+	 * registers connected. Only r6 - r9 of the callers are alive (pushed
+	 * to the stack implicitly by JITs) so in callers' frames connect just
+	 * r6 - r9 as an optimization. Callers will have r1 - r5 connected to
+	 * the state of the call instruction (with WRITTEN set), and r0 comes
+	 * from callee with its full parentage chain, anyway.
+	 */
+	/* clear write marks in current state: the writes we did are not writes
+	 * our child did, so they don't screen off its reads from us.
+	 * (There are no read marks in current state, because reads always mark
+	 * their parent and current state never has children yet.  Only
+	 * explored_states can get read marks.)
+	 */
+	for (j = 0; j <= cur->curframe; j++) {
+		for (i = j < cur->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++)
+			cur->frame[j]->regs[i].parent = &new->frame[j]->regs[i];
+		for (i = 0; i < BPF_REG_FP; i++)
+			cur->frame[j]->regs[i].live = REG_LIVE_NONE;
+	}
+
+	/* all stack frames are accessible from callee, clear them all */
+	for (j = 0; j <= cur->curframe; j++) {
+		struct bpf_func_state *frame = cur->frame[j];
+		struct bpf_func_state *newframe = new->frame[j];
+
+		for (i = 0; i < frame->allocated_stack / BPF_REG_SIZE; i++) {
+			frame->stack[i].spilled_ptr.live = REG_LIVE_NONE;
+			frame->stack[i].spilled_ptr.parent =
+						&newframe->stack[i].spilled_ptr;
+		}
+	}
+	return 0;
+}
+
+/* Return true if it's OK to have the same insn return a different type. */
+static bool reg_type_mismatch_ok(enum bpf_reg_type type)
+{
+	switch (type) {
+	case PTR_TO_CTX:
+	case PTR_TO_SOCKET:
+	case PTR_TO_SOCKET_OR_NULL:
+	case PTR_TO_SOCK_COMMON:
+	case PTR_TO_SOCK_COMMON_OR_NULL:
+	case PTR_TO_TCP_SOCK:
+	case PTR_TO_TCP_SOCK_OR_NULL:
+	case PTR_TO_XDP_SOCK:
+	case PTR_TO_BTF_ID:
+	case PTR_TO_BTF_ID_OR_NULL:
+		return false;
+	default:
+		return true;
+	}
+}
+
+/* If an instruction was previously used with particular pointer types, then we
+ * need to be careful to avoid cases such as the below, where it may be ok
+ * for one branch accessing the pointer, but not ok for the other branch:
+ *
+ * R1 = sock_ptr
+ * goto X;
+ * ...
+ * R1 = some_other_valid_ptr;
+ * goto X;
+ * ...
+ * R2 = *(u32 *)(R1 + 0);
+ */
+static bool reg_type_mismatch(enum bpf_reg_type src, enum bpf_reg_type prev)
+{
+	return src != prev && (!reg_type_mismatch_ok(src) ||
+			       !reg_type_mismatch_ok(prev));
+}
+
+static int do_check(struct bpf_verifier_env *env)
+{
+	bool pop_log = !(env->log.level & BPF_LOG_LEVEL2);
+	struct bpf_verifier_state *state = env->cur_state;
+	struct bpf_insn *insns = env->prog->insnsi;
+	struct bpf_reg_state *regs;
+	int insn_cnt = env->prog->len;
+	bool do_print_state = false;
+	int prev_insn_idx = -1;
+
+	for (;;) {
+		struct bpf_insn *insn;
+		u8 class;
+		int err;
+
+		env->prev_insn_idx = prev_insn_idx;
+		if (env->insn_idx >= insn_cnt) {
+			verbose(env, "invalid insn idx %d insn_cnt %d\n",
+				env->insn_idx, insn_cnt);
+			return -EFAULT;
+		}
+
+		insn = &insns[env->insn_idx];
+		class = BPF_CLASS(insn->code);
+
+		if (++env->insn_processed > BPF_COMPLEXITY_LIMIT_INSNS) {
+			verbose(env,
+				"BPF program is too large. Processed %d insn\n",
+				env->insn_processed);
+			return -E2BIG;
+		}
+
+		err = is_state_visited(env, env->insn_idx);
+		if (err < 0)
+			return err;
+		if (err == 1) {
+			/* found equivalent state, can prune the search */
+			if (env->log.level & BPF_LOG_LEVEL) {
+				if (do_print_state)
+					verbose(env, "\nfrom %d to %d%s: safe\n",
+						env->prev_insn_idx, env->insn_idx,
+						env->cur_state->speculative ?
+						" (speculative execution)" : "");
+				else
+					verbose(env, "%d: safe\n", env->insn_idx);
+			}
+			goto process_bpf_exit;
+		}
+
+		if (signal_pending(current))
+			return -EAGAIN;
+
+		if (need_resched())
+			cond_resched();
+
+		if (env->log.level & BPF_LOG_LEVEL2 ||
+		    (env->log.level & BPF_LOG_LEVEL && do_print_state)) {
+			if (env->log.level & BPF_LOG_LEVEL2)
+				verbose(env, "%d:", env->insn_idx);
+			else
+				verbose(env, "\nfrom %d to %d%s:",
+					env->prev_insn_idx, env->insn_idx,
+					env->cur_state->speculative ?
+					" (speculative execution)" : "");
+			print_verifier_state(env, state->frame[state->curframe]);
+			do_print_state = false;
+		}
+
+		if (env->log.level & BPF_LOG_LEVEL) {
+			const struct bpf_insn_cbs cbs = {
+				.cb_print	= verbose,
+				.private_data	= env,
+			};
+
+			verbose_linfo(env, env->insn_idx, "; ");
+			verbose(env, "%d: ", env->insn_idx);
+			print_bpf_insn(&cbs, insn, env->allow_ptr_leaks);
+		}
+
+		if (bpf_prog_is_dev_bound(env->prog->aux)) {
+			err = bpf_prog_offload_verify_insn(env, env->insn_idx,
+							   env->prev_insn_idx);
+			if (err)
+				return err;
+		}
+
+		regs = cur_regs(env);
+		sanitize_mark_insn_seen(env);
+		prev_insn_idx = env->insn_idx;
+
+		if (class == BPF_ALU || class == BPF_ALU64) {
+			err = check_alu_op(env, insn);
+			if (err)
+				return err;
+
+		} else if (class == BPF_LDX) {
+			enum bpf_reg_type *prev_src_type, src_reg_type;
+
+			/* check for reserved fields is already done */
+
+			/* check src operand */
+			err = check_reg_arg(env, insn->src_reg, SRC_OP);
+			if (err)
+				return err;
+
+			err = check_reg_arg(env, insn->dst_reg, DST_OP_NO_MARK);
+			if (err)
+				return err;
+
+			src_reg_type = regs[insn->src_reg].type;
+
+			/* check that memory (src_reg + off) is readable,
+			 * the state of dst_reg will be updated by this func
+			 */
+			err = check_mem_access(env, env->insn_idx, insn->src_reg,
+					       insn->off, BPF_SIZE(insn->code),
+					       BPF_READ, insn->dst_reg, false);
+			if (err)
+				return err;
+
+			prev_src_type = &env->insn_aux_data[env->insn_idx].ptr_type;
+
+			if (*prev_src_type == NOT_INIT) {
+				/* saw a valid insn
+				 * dst_reg = *(u32 *)(src_reg + off)
+				 * save type to validate intersecting paths
+				 */
+				*prev_src_type = src_reg_type;
+
+			} else if (reg_type_mismatch(src_reg_type, *prev_src_type)) {
+				/* ABuser program is trying to use the same insn
+				 * dst_reg = *(u32*) (src_reg + off)
+				 * with different pointer types:
+				 * src_reg == ctx in one branch and
+				 * src_reg == stack|map in some other branch.
+				 * Reject it.
+				 */
+				verbose(env, "same insn cannot be used with different pointers\n");
+				return -EINVAL;
+			}
+
+		} else if (class == BPF_STX) {
+			enum bpf_reg_type *prev_dst_type, dst_reg_type;
+
+			if (BPF_MODE(insn->code) == BPF_XADD) {
+				err = check_xadd(env, env->insn_idx, insn);
+				if (err)
+					return err;
+				env->insn_idx++;
+				continue;
+			}
+
+			/* check src1 operand */
+			err = check_reg_arg(env, insn->src_reg, SRC_OP);
+			if (err)
+				return err;
+			/* check src2 operand */
+			err = check_reg_arg(env, insn->dst_reg, SRC_OP);
+			if (err)
+				return err;
+
+			dst_reg_type = regs[insn->dst_reg].type;
+
+			/* check that memory (dst_reg + off) is writeable */
+			err = check_mem_access(env, env->insn_idx, insn->dst_reg,
+					       insn->off, BPF_SIZE(insn->code),
+					       BPF_WRITE, insn->src_reg, false);
+			if (err)
+				return err;
+
+			prev_dst_type = &env->insn_aux_data[env->insn_idx].ptr_type;
+
+			if (*prev_dst_type == NOT_INIT) {
+				*prev_dst_type = dst_reg_type;
+			} else if (reg_type_mismatch(dst_reg_type, *prev_dst_type)) {
+				verbose(env, "same insn cannot be used with different pointers\n");
+				return -EINVAL;
+			}
+
+		} else if (class == BPF_ST) {
+			if (BPF_MODE(insn->code) != BPF_MEM ||
+			    insn->src_reg != BPF_REG_0) {
+				verbose(env, "BPF_ST uses reserved fields\n");
+				return -EINVAL;
+			}
+			/* check src operand */
+			err = check_reg_arg(env, insn->dst_reg, SRC_OP);
+			if (err)
+				return err;
+
+			if (is_ctx_reg(env, insn->dst_reg)) {
+				verbose(env, "BPF_ST stores into R%d %s is not allowed\n",
+					insn->dst_reg,
+					reg_type_str[reg_state(env, insn->dst_reg)->type]);
+				return -EACCES;
+			}
+
+			/* check that memory (dst_reg + off) is writeable */
+			err = check_mem_access(env, env->insn_idx, insn->dst_reg,
+					       insn->off, BPF_SIZE(insn->code),
+					       BPF_WRITE, -1, false);
+			if (err)
+				return err;
+
+		} else if (class == BPF_JMP || class == BPF_JMP32) {
+			u8 opcode = BPF_OP(insn->code);
+
+			env->jmps_processed++;
+			if (opcode == BPF_CALL) {
+				if (BPF_SRC(insn->code) != BPF_K ||
+				    insn->off != 0 ||
+				    (insn->src_reg != BPF_REG_0 &&
+				     insn->src_reg != BPF_PSEUDO_CALL) ||
+				    insn->dst_reg != BPF_REG_0 ||
+				    class == BPF_JMP32) {
+					verbose(env, "BPF_CALL uses reserved fields\n");
+					return -EINVAL;
+				}
+
+				if (env->cur_state->active_spin_lock &&
+				    (insn->src_reg == BPF_PSEUDO_CALL ||
+				     insn->imm != BPF_FUNC_spin_unlock)) {
+					verbose(env, "function calls are not allowed while holding a lock\n");
+					return -EINVAL;
+				}
+				if (insn->src_reg == BPF_PSEUDO_CALL)
+					err = check_func_call(env, insn, &env->insn_idx);
+				else
+					err = check_helper_call(env, insn->imm, env->insn_idx);
+				if (err)
+					return err;
+
+			} else if (opcode == BPF_JA) {
+				if (BPF_SRC(insn->code) != BPF_K ||
+				    insn->imm != 0 ||
+				    insn->src_reg != BPF_REG_0 ||
+				    insn->dst_reg != BPF_REG_0 ||
+				    class == BPF_JMP32) {
+					verbose(env, "BPF_JA uses reserved fields\n");
+					return -EINVAL;
+				}
+
+				env->insn_idx += insn->off + 1;
+				continue;
+
+			} else if (opcode == BPF_EXIT) {
+				if (BPF_SRC(insn->code) != BPF_K ||
+				    insn->imm != 0 ||
+				    insn->src_reg != BPF_REG_0 ||
+				    insn->dst_reg != BPF_REG_0 ||
+				    class == BPF_JMP32) {
+					verbose(env, "BPF_EXIT uses reserved fields\n");
+					return -EINVAL;
+				}
+
+				if (env->cur_state->active_spin_lock) {
+					verbose(env, "bpf_spin_unlock is missing\n");
+					return -EINVAL;
+				}
+
+				if (state->curframe) {
+					/* exit from nested function */
+					err = prepare_func_exit(env, &env->insn_idx);
+					if (err)
+						return err;
+					do_print_state = true;
+					continue;
+				}
+
+				err = check_reference_leak(env);
+				if (err)
+					return err;
+
+				err = check_return_code(env);
+				if (err)
+					return err;
+process_bpf_exit:
+				update_branch_counts(env, env->cur_state);
+				err = pop_stack(env, &prev_insn_idx,
+						&env->insn_idx, pop_log);
+				if (err < 0) {
+					if (err != -ENOENT)
+						return err;
+					break;
+				} else {
+					do_print_state = true;
+					continue;
+				}
+			} else {
+				err = check_cond_jmp_op(env, insn, &env->insn_idx);
+				if (err)
+					return err;
+			}
+		} else if (class == BPF_LD) {
+			u8 mode = BPF_MODE(insn->code);
+
+			if (mode == BPF_ABS || mode == BPF_IND) {
+				err = check_ld_abs(env, insn);
+				if (err)
+					return err;
+
+			} else if (mode == BPF_IMM) {
+				err = check_ld_imm(env, insn);
+				if (err)
+					return err;
+
+				env->insn_idx++;
+				sanitize_mark_insn_seen(env);
+			} else {
+				verbose(env, "invalid BPF_LD mode\n");
+				return -EINVAL;
+			}
+		} else {
+			verbose(env, "unknown insn class %d\n", class);
+			return -EINVAL;
+		}
+
+		env->insn_idx++;
+	}
+
+	return 0;
+}
+
+/* replace pseudo btf_id with kernel symbol address */
+static int check_pseudo_btf_id(struct bpf_verifier_env *env,
+			       struct bpf_insn *insn,
+			       struct bpf_insn_aux_data *aux)
+{
+	const struct btf_var_secinfo *vsi;
+	const struct btf_type *datasec;
+	const struct btf_type *t;
+	const char *sym_name;
+	bool percpu = false;
+	u32 type, id = insn->imm;
+	s32 datasec_id;
+	u64 addr;
+	int i;
+
+	if (!btf_vmlinux) {
+		verbose(env, "kernel is missing BTF, make sure CONFIG_DEBUG_INFO_BTF=y is specified in Kconfig.\n");
+		return -EINVAL;
+	}
+
+	if (insn[1].imm != 0) {
+		verbose(env, "reserved field (insn[1].imm) is used in pseudo_btf_id ldimm64 insn.\n");
+		return -EINVAL;
+	}
+
+	t = btf_type_by_id(btf_vmlinux, id);
+	if (!t) {
+		verbose(env, "ldimm64 insn specifies invalid btf_id %d.\n", id);
+		return -ENOENT;
+	}
+
+	if (!btf_type_is_var(t)) {
+		verbose(env, "pseudo btf_id %d in ldimm64 isn't KIND_VAR.\n",
+			id);
+		return -EINVAL;
+	}
+
+	sym_name = btf_name_by_offset(btf_vmlinux, t->name_off);
+	addr = kallsyms_lookup_name(sym_name);
+	if (!addr) {
+		verbose(env, "ldimm64 failed to find the address for kernel symbol '%s'.\n",
+			sym_name);
+		return -ENOENT;
+	}
+
+	datasec_id = btf_find_by_name_kind(btf_vmlinux, ".data..percpu",
+					   BTF_KIND_DATASEC);
+	if (datasec_id > 0) {
+		datasec = btf_type_by_id(btf_vmlinux, datasec_id);
+		for_each_vsi(i, datasec, vsi) {
+			if (vsi->type == id) {
+				percpu = true;
+				break;
+			}
+		}
+	}
+
+	insn[0].imm = (u32)addr;
+	insn[1].imm = addr >> 32;
+
+	type = t->type;
+	t = btf_type_skip_modifiers(btf_vmlinux, type, NULL);
+	if (percpu) {
+		aux->btf_var.reg_type = PTR_TO_PERCPU_BTF_ID;
+		aux->btf_var.btf_id = type;
+	} else if (!btf_type_is_struct(t)) {
+		const struct btf_type *ret;
+		const char *tname;
+		u32 tsize;
+
+		/* resolve the type size of ksym. */
+		ret = btf_resolve_size(btf_vmlinux, t, &tsize);
+		if (IS_ERR(ret)) {
+			tname = btf_name_by_offset(btf_vmlinux, t->name_off);
+			verbose(env, "ldimm64 unable to resolve the size of type '%s': %ld\n",
+				tname, PTR_ERR(ret));
+			return -EINVAL;
+		}
+		aux->btf_var.reg_type = PTR_TO_MEM;
+		aux->btf_var.mem_size = tsize;
+	} else {
+		aux->btf_var.reg_type = PTR_TO_BTF_ID;
+		aux->btf_var.btf_id = type;
+	}
+	return 0;
+}
+
+static int check_map_prealloc(struct bpf_map *map)
+{
+	return (map->map_type != BPF_MAP_TYPE_HASH &&
+		map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
+		map->map_type != BPF_MAP_TYPE_HASH_OF_MAPS) ||
+		!(map->map_flags & BPF_F_NO_PREALLOC);
+}
+
+static bool is_tracing_prog_type(enum bpf_prog_type type)
+{
+	switch (type) {
+	case BPF_PROG_TYPE_KPROBE:
+	case BPF_PROG_TYPE_TRACEPOINT:
+	case BPF_PROG_TYPE_PERF_EVENT:
+	case BPF_PROG_TYPE_RAW_TRACEPOINT:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool is_preallocated_map(struct bpf_map *map)
+{
+	if (!check_map_prealloc(map))
+		return false;
+	if (map->inner_map_meta && !check_map_prealloc(map->inner_map_meta))
+		return false;
+	return true;
+}
+
+static int check_map_prog_compatibility(struct bpf_verifier_env *env,
+					struct bpf_map *map,
+					struct bpf_prog *prog)
+
+{
+	enum bpf_prog_type prog_type = resolve_prog_type(prog);
+	/*
+	 * Validate that trace type programs use preallocated hash maps.
+	 *
+	 * For programs attached to PERF events this is mandatory as the
+	 * perf NMI can hit any arbitrary code sequence.
+	 *
+	 * All other trace types using preallocated hash maps are unsafe as
+	 * well because tracepoint or kprobes can be inside locked regions
+	 * of the memory allocator or at a place where a recursion into the
+	 * memory allocator would see inconsistent state.
+	 *
+	 * On RT enabled kernels run-time allocation of all trace type
+	 * programs is strictly prohibited due to lock type constraints. On
+	 * !RT kernels it is allowed for backwards compatibility reasons for
+	 * now, but warnings are emitted so developers are made aware of
+	 * the unsafety and can fix their programs before this is enforced.
+	 */
+	if (is_tracing_prog_type(prog_type) && !is_preallocated_map(map)) {
+		if (prog_type == BPF_PROG_TYPE_PERF_EVENT) {
+			verbose(env, "perf_event programs can only use preallocated hash map\n");
+			return -EINVAL;
+		}
+		if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+			verbose(env, "trace type programs can only use preallocated hash map\n");
+			return -EINVAL;
+		}
+		WARN_ONCE(1, "trace type BPF program uses run-time allocation\n");
+		verbose(env, "trace type programs with run-time allocated hash maps are unsafe. Switch to preallocated hash maps.\n");
+	}
+
+	if ((is_tracing_prog_type(prog_type) ||
+	     prog_type == BPF_PROG_TYPE_SOCKET_FILTER) &&
+	    map_value_has_spin_lock(map)) {
+		verbose(env, "tracing progs cannot use bpf_spin_lock yet\n");
+		return -EINVAL;
+	}
+
+	if ((bpf_prog_is_dev_bound(prog->aux) || bpf_map_is_dev_bound(map)) &&
+	    !bpf_offload_prog_map_match(prog, map)) {
+		verbose(env, "offload device mismatch between prog and map\n");
+		return -EINVAL;
+	}
+
+	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
+		verbose(env, "bpf_struct_ops map cannot be used in prog\n");
+		return -EINVAL;
+	}
+
+	if (prog->aux->sleepable)
+		switch (map->map_type) {
+		case BPF_MAP_TYPE_HASH:
+		case BPF_MAP_TYPE_LRU_HASH:
+		case BPF_MAP_TYPE_ARRAY:
+			if (!is_preallocated_map(map)) {
+				verbose(env,
+					"Sleepable programs can only use preallocated hash maps\n");
+				return -EINVAL;
+			}
+			break;
+		default:
+			verbose(env,
+				"Sleepable programs can only use array and hash maps\n");
+			return -EINVAL;
+		}
+
+	return 0;
+}
+
+static bool bpf_map_is_cgroup_storage(struct bpf_map *map)
+{
+	return (map->map_type == BPF_MAP_TYPE_CGROUP_STORAGE ||
+		map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
+}
+
+/* find and rewrite pseudo imm in ld_imm64 instructions:
+ *
+ * 1. if it accesses map FD, replace it with actual map pointer.
+ * 2. if it accesses btf_id of a VAR, replace it with pointer to the var.
+ *
+ * NOTE: btf_vmlinux is required for converting pseudo btf_id.
+ */
+static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
+{
+	struct bpf_insn *insn = env->prog->insnsi;
+	int insn_cnt = env->prog->len;
+	int i, j, err;
+
+	err = bpf_prog_calc_tag(env->prog);
+	if (err)
+		return err;
+
+	for (i = 0; i < insn_cnt; i++, insn++) {
+		if (BPF_CLASS(insn->code) == BPF_LDX &&
+		    (BPF_MODE(insn->code) != BPF_MEM || insn->imm != 0)) {
+			verbose(env, "BPF_LDX uses reserved fields\n");
+			return -EINVAL;
+		}
+
+		if (BPF_CLASS(insn->code) == BPF_STX &&
+		    ((BPF_MODE(insn->code) != BPF_MEM &&
+		      BPF_MODE(insn->code) != BPF_XADD) || insn->imm != 0)) {
+			verbose(env, "BPF_STX uses reserved fields\n");
+			return -EINVAL;
+		}
+
+		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW)) {
+			struct bpf_insn_aux_data *aux;
+			struct bpf_map *map;
+			struct fd f;
+			u64 addr;
+
+			if (i == insn_cnt - 1 || insn[1].code != 0 ||
+			    insn[1].dst_reg != 0 || insn[1].src_reg != 0 ||
+			    insn[1].off != 0) {
+				verbose(env, "invalid bpf_ld_imm64 insn\n");
+				return -EINVAL;
+			}
+
+			if (insn[0].src_reg == 0)
+				/* valid generic load 64-bit imm */
+				goto next_insn;
+
+			if (insn[0].src_reg == BPF_PSEUDO_BTF_ID) {
+				aux = &env->insn_aux_data[i];
+				err = check_pseudo_btf_id(env, insn, aux);
+				if (err)
+					return err;
+				goto next_insn;
+			}
+
+			/* In final convert_pseudo_ld_imm64() step, this is
+			 * converted into regular 64-bit imm load insn.
+			 */
+			if ((insn[0].src_reg != BPF_PSEUDO_MAP_FD &&
+			     insn[0].src_reg != BPF_PSEUDO_MAP_VALUE) ||
+			    (insn[0].src_reg == BPF_PSEUDO_MAP_FD &&
+			     insn[1].imm != 0)) {
+				verbose(env,
+					"unrecognized bpf_ld_imm64 insn\n");
+				return -EINVAL;
+			}
+
+			f = fdget(insn[0].imm);
+			map = __bpf_map_get(f);
+			if (IS_ERR(map)) {
+				verbose(env, "fd %d is not pointing to valid bpf_map\n",
+					insn[0].imm);
+				return PTR_ERR(map);
+			}
+
+			err = check_map_prog_compatibility(env, map, env->prog);
+			if (err) {
+				fdput(f);
+				return err;
+			}
+
+			aux = &env->insn_aux_data[i];
+			if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+				addr = (unsigned long)map;
+			} else {
+				u32 off = insn[1].imm;
+
+				if (off >= BPF_MAX_VAR_OFF) {
+					verbose(env, "direct value offset of %u is not allowed\n", off);
+					fdput(f);
+					return -EINVAL;
+				}
+
+				if (!map->ops->map_direct_value_addr) {
+					verbose(env, "no direct value access support for this map type\n");
+					fdput(f);
+					return -EINVAL;
+				}
+
+				err = map->ops->map_direct_value_addr(map, &addr, off);
+				if (err) {
+					verbose(env, "invalid access to map value pointer, value_size=%u off=%u\n",
+						map->value_size, off);
+					fdput(f);
+					return err;
+				}
+
+				aux->map_off = off;
+				addr += off;
+			}
+
+			insn[0].imm = (u32)addr;
+			insn[1].imm = addr >> 32;
+
+			/* check whether we recorded this map already */
+			for (j = 0; j < env->used_map_cnt; j++) {
+				if (env->used_maps[j] == map) {
+					aux->map_index = j;
+					fdput(f);
+					goto next_insn;
+				}
+			}
+
+			if (env->used_map_cnt >= MAX_USED_MAPS) {
+				fdput(f);
+				return -E2BIG;
+			}
+
+			/* hold the map. If the program is rejected by verifier,
+			 * the map will be released by release_maps() or it
+			 * will be used by the valid program until it's unloaded
+			 * and all maps are released in free_used_maps()
+			 */
+			bpf_map_inc(map);
+
+			aux->map_index = env->used_map_cnt;
+			env->used_maps[env->used_map_cnt++] = map;
+
+			if (bpf_map_is_cgroup_storage(map) &&
+			    bpf_cgroup_storage_assign(env->prog->aux, map)) {
+				verbose(env, "only one cgroup storage of each type is allowed\n");
+				fdput(f);
+				return -EBUSY;
+			}
+
+			fdput(f);
+next_insn:
+			insn++;
+			i++;
+			continue;
+		}
+
+		/* Basic sanity check before we invest more work here. */
+		if (!bpf_opcode_in_insntable(insn->code)) {
+			verbose(env, "unknown opcode %02x\n", insn->code);
+			return -EINVAL;
+		}
+	}
+
+	/* now all pseudo BPF_LD_IMM64 instructions load valid
+	 * 'struct bpf_map *' into a register instead of user map_fd.
+	 * These pointers will be used later by verifier to validate map access.
+	 */
+	return 0;
+}
+
+/* drop refcnt of maps used by the rejected program */
+static void release_maps(struct bpf_verifier_env *env)
+{
+	__bpf_free_used_maps(env->prog->aux, env->used_maps,
+			     env->used_map_cnt);
+}
+
+/* convert pseudo BPF_LD_IMM64 into generic BPF_LD_IMM64 */
+static void convert_pseudo_ld_imm64(struct bpf_verifier_env *env)
+{
+	struct bpf_insn *insn = env->prog->insnsi;
+	int insn_cnt = env->prog->len;
+	int i;
+
+	for (i = 0; i < insn_cnt; i++, insn++)
+		if (insn->code == (BPF_LD | BPF_IMM | BPF_DW))
+			insn->src_reg = 0;
+}
+
+/* single env->prog->insni[off] instruction was replaced with the range
+ * insni[off, off + cnt).  Adjust corresponding insn_aux_data by copying
+ * [0, off) and [off, end) to new locations, so the patched range stays zero
+ */
+static void adjust_insn_aux_data(struct bpf_verifier_env *env,
+				 struct bpf_insn_aux_data *new_data,
+				 struct bpf_prog *new_prog, u32 off, u32 cnt)
+{
+	struct bpf_insn_aux_data *old_data = env->insn_aux_data;
+	struct bpf_insn *insn = new_prog->insnsi;
+	u32 old_seen = old_data[off].seen;
+	u32 prog_len;
+	int i;
+
+	/* aux info at OFF always needs adjustment, no matter fast path
+	 * (cnt == 1) is taken or not. There is no guarantee INSN at OFF is the
+	 * original insn at old prog.
+	 */
+	old_data[off].zext_dst = insn_has_def32(env, insn + off + cnt - 1);
+
+	if (cnt == 1)
+		return;
+	prog_len = new_prog->len;
+
+	memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off);
+	memcpy(new_data + off + cnt - 1, old_data + off,
+	       sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1));
+	for (i = off; i < off + cnt - 1; i++) {
+		/* Expand insni[off]'s seen count to the patched range. */
+		new_data[i].seen = old_seen;
+		new_data[i].zext_dst = insn_has_def32(env, insn + i);
+	}
+	env->insn_aux_data = new_data;
+	vfree(old_data);
+}
+
+static void adjust_subprog_starts(struct bpf_verifier_env *env, u32 off, u32 len)
+{
+	int i;
+
+	if (len == 1)
+		return;
+	/* NOTE: fake 'exit' subprog should be updated as well. */
+	for (i = 0; i <= env->subprog_cnt; i++) {
+		if (env->subprog_info[i].start <= off)
+			continue;
+		env->subprog_info[i].start += len - 1;
+	}
+}
+
+static void adjust_poke_descs(struct bpf_prog *prog, u32 off, u32 len)
+{
+	struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
+	int i, sz = prog->aux->size_poke_tab;
+	struct bpf_jit_poke_descriptor *desc;
+
+	for (i = 0; i < sz; i++) {
+		desc = &tab[i];
+		if (desc->insn_idx <= off)
+			continue;
+		desc->insn_idx += len - 1;
+	}
+}
+
+static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 off,
+					    const struct bpf_insn *patch, u32 len)
+{
+	struct bpf_prog *new_prog;
+	struct bpf_insn_aux_data *new_data = NULL;
+
+	if (len > 1) {
+		new_data = vzalloc(array_size(env->prog->len + len - 1,
+					      sizeof(struct bpf_insn_aux_data)));
+		if (!new_data)
+			return NULL;
+	}
+
+	new_prog = bpf_patch_insn_single(env->prog, off, patch, len);
+	if (IS_ERR(new_prog)) {
+		if (PTR_ERR(new_prog) == -ERANGE)
+			verbose(env,
+				"insn %d cannot be patched due to 16-bit range\n",
+				env->insn_aux_data[off].orig_idx);
+		vfree(new_data);
+		return NULL;
+	}
+	adjust_insn_aux_data(env, new_data, new_prog, off, len);
+	adjust_subprog_starts(env, off, len);
+	adjust_poke_descs(new_prog, off, len);
+	return new_prog;
+}
+
+static int adjust_subprog_starts_after_remove(struct bpf_verifier_env *env,
+					      u32 off, u32 cnt)
+{
+	int i, j;
+
+	/* find first prog starting at or after off (first to remove) */
+	for (i = 0; i < env->subprog_cnt; i++)
+		if (env->subprog_info[i].start >= off)
+			break;
+	/* find first prog starting at or after off + cnt (first to stay) */
+	for (j = i; j < env->subprog_cnt; j++)
+		if (env->subprog_info[j].start >= off + cnt)
+			break;
+	/* if j doesn't start exactly at off + cnt, we are just removing
+	 * the front of previous prog
+	 */
+	if (env->subprog_info[j].start != off + cnt)
+		j--;
+
+	if (j > i) {
+		struct bpf_prog_aux *aux = env->prog->aux;
+		int move;
+
+		/* move fake 'exit' subprog as well */
+		move = env->subprog_cnt + 1 - j;
+
+		memmove(env->subprog_info + i,
+			env->subprog_info + j,
+			sizeof(*env->subprog_info) * move);
+		env->subprog_cnt -= j - i;
+
+		/* remove func_info */
+		if (aux->func_info) {
+			move = aux->func_info_cnt - j;
+
+			memmove(aux->func_info + i,
+				aux->func_info + j,
+				sizeof(*aux->func_info) * move);
+			aux->func_info_cnt -= j - i;
+			/* func_info->insn_off is set after all code rewrites,
+			 * in adjust_btf_func() - no need to adjust
+			 */
+		}
+	} else {
+		/* convert i from "first prog to remove" to "first to adjust" */
+		if (env->subprog_info[i].start == off)
+			i++;
+	}
+
+	/* update fake 'exit' subprog as well */
+	for (; i <= env->subprog_cnt; i++)
+		env->subprog_info[i].start -= cnt;
+
+	return 0;
+}
+
+static int bpf_adj_linfo_after_remove(struct bpf_verifier_env *env, u32 off,
+				      u32 cnt)
+{
+	struct bpf_prog *prog = env->prog;
+	u32 i, l_off, l_cnt, nr_linfo;
+	struct bpf_line_info *linfo;
+
+	nr_linfo = prog->aux->nr_linfo;
+	if (!nr_linfo)
+		return 0;
+
+	linfo = prog->aux->linfo;
+
+	/* find first line info to remove, count lines to be removed */
+	for (i = 0; i < nr_linfo; i++)
+		if (linfo[i].insn_off >= off)
+			break;
+
+	l_off = i;
+	l_cnt = 0;
+	for (; i < nr_linfo; i++)
+		if (linfo[i].insn_off < off + cnt)
+			l_cnt++;
+		else
+			break;
+
+	/* First live insn doesn't match first live linfo, it needs to "inherit"
+	 * last removed linfo.  prog is already modified, so prog->len == off
+	 * means no live instructions after (tail of the program was removed).
+	 */
+	if (prog->len != off && l_cnt &&
+	    (i == nr_linfo || linfo[i].insn_off != off + cnt)) {
+		l_cnt--;
+		linfo[--i].insn_off = off + cnt;
+	}
+
+	/* remove the line info which refer to the removed instructions */
+	if (l_cnt) {
+		memmove(linfo + l_off, linfo + i,
+			sizeof(*linfo) * (nr_linfo - i));
+
+		prog->aux->nr_linfo -= l_cnt;
+		nr_linfo = prog->aux->nr_linfo;
+	}
+
+	/* pull all linfo[i].insn_off >= off + cnt in by cnt */
+	for (i = l_off; i < nr_linfo; i++)
+		linfo[i].insn_off -= cnt;
+
+	/* fix up all subprogs (incl. 'exit') which start >= off */
+	for (i = 0; i <= env->subprog_cnt; i++)
+		if (env->subprog_info[i].linfo_idx > l_off) {
+			/* program may have started in the removed region but
+			 * may not be fully removed
+			 */
+			if (env->subprog_info[i].linfo_idx >= l_off + l_cnt)
+				env->subprog_info[i].linfo_idx -= l_cnt;
+			else
+				env->subprog_info[i].linfo_idx = l_off;
+		}
+
+	return 0;
+}
+
+static int verifier_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt)
+{
+	struct bpf_insn_aux_data *aux_data = env->insn_aux_data;
+	unsigned int orig_prog_len = env->prog->len;
+	int err;
+
+	if (bpf_prog_is_dev_bound(env->prog->aux))
+		bpf_prog_offload_remove_insns(env, off, cnt);
+
+	err = bpf_remove_insns(env->prog, off, cnt);
+	if (err)
+		return err;
+
+	err = adjust_subprog_starts_after_remove(env, off, cnt);
+	if (err)
+		return err;
+
+	err = bpf_adj_linfo_after_remove(env, off, cnt);
+	if (err)
+		return err;
+
+	memmove(aux_data + off,	aux_data + off + cnt,
+		sizeof(*aux_data) * (orig_prog_len - off - cnt));
+
+	return 0;
+}
+
+/* The verifier does more data flow analysis than llvm and will not
+ * explore branches that are dead at run time. Malicious programs can
+ * have dead code too. Therefore replace all dead at-run-time code
+ * with 'ja -1'.
+ *
+ * Just nops are not optimal, e.g. if they would sit at the end of the
+ * program and through another bug we would manage to jump there, then
+ * we'd execute beyond program memory otherwise. Returning exception
+ * code also wouldn't work since we can have subprogs where the dead
+ * code could be located.
+ */
+static void sanitize_dead_code(struct bpf_verifier_env *env)
+{
+	struct bpf_insn_aux_data *aux_data = env->insn_aux_data;
+	struct bpf_insn trap = BPF_JMP_IMM(BPF_JA, 0, 0, -1);
+	struct bpf_insn *insn = env->prog->insnsi;
+	const int insn_cnt = env->prog->len;
+	int i;
+
+	for (i = 0; i < insn_cnt; i++) {
+		if (aux_data[i].seen)
+			continue;
+		memcpy(insn + i, &trap, sizeof(trap));
+		aux_data[i].zext_dst = false;
+	}
+}
+
+static bool insn_is_cond_jump(u8 code)
+{
+	u8 op;
+
+	if (BPF_CLASS(code) == BPF_JMP32)
+		return true;
+
+	if (BPF_CLASS(code) != BPF_JMP)
+		return false;
+
+	op = BPF_OP(code);
+	return op != BPF_JA && op != BPF_EXIT && op != BPF_CALL;
+}
+
+static void opt_hard_wire_dead_code_branches(struct bpf_verifier_env *env)
+{
+	struct bpf_insn_aux_data *aux_data = env->insn_aux_data;
+	struct bpf_insn ja = BPF_JMP_IMM(BPF_JA, 0, 0, 0);
+	struct bpf_insn *insn = env->prog->insnsi;
+	const int insn_cnt = env->prog->len;
+	int i;
+
+	for (i = 0; i < insn_cnt; i++, insn++) {
+		if (!insn_is_cond_jump(insn->code))
+			continue;
+
+		if (!aux_data[i + 1].seen)
+			ja.off = insn->off;
+		else if (!aux_data[i + 1 + insn->off].seen)
+			ja.off = 0;
+		else
+			continue;
+
+		if (bpf_prog_is_dev_bound(env->prog->aux))
+			bpf_prog_offload_replace_insn(env, i, &ja);
+
+		memcpy(insn, &ja, sizeof(ja));
+	}
+}
+
+static int opt_remove_dead_code(struct bpf_verifier_env *env)
+{
+	struct bpf_insn_aux_data *aux_data = env->insn_aux_data;
+	int insn_cnt = env->prog->len;
+	int i, err;
+
+	for (i = 0; i < insn_cnt; i++) {
+		int j;
+
+		j = 0;
+		while (i + j < insn_cnt && !aux_data[i + j].seen)
+			j++;
+		if (!j)
+			continue;
+
+		err = verifier_remove_insns(env, i, j);
+		if (err)
+			return err;
+		insn_cnt = env->prog->len;
+	}
+
+	return 0;
+}
+
+static int opt_remove_nops(struct bpf_verifier_env *env)
+{
+	const struct bpf_insn ja = BPF_JMP_IMM(BPF_JA, 0, 0, 0);
+	struct bpf_insn *insn = env->prog->insnsi;
+	int insn_cnt = env->prog->len;
+	int i, err;
+
+	for (i = 0; i < insn_cnt; i++) {
+		if (memcmp(&insn[i], &ja, sizeof(ja)))
+			continue;
+
+		err = verifier_remove_insns(env, i, 1);
+		if (err)
+			return err;
+		insn_cnt--;
+		i--;
+	}
+
+	return 0;
+}
+
+static int opt_subreg_zext_lo32_rnd_hi32(struct bpf_verifier_env *env,
+					 const union bpf_attr *attr)
+{
+	struct bpf_insn *patch, zext_patch[2], rnd_hi32_patch[4];
+	struct bpf_insn_aux_data *aux = env->insn_aux_data;
+	int i, patch_len, delta = 0, len = env->prog->len;
+	struct bpf_insn *insns = env->prog->insnsi;
+	struct bpf_prog *new_prog;
+	bool rnd_hi32;
+
+	rnd_hi32 = attr->prog_flags & BPF_F_TEST_RND_HI32;
+	zext_patch[1] = BPF_ZEXT_REG(0);
+	rnd_hi32_patch[1] = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, 0);
+	rnd_hi32_patch[2] = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
+	rnd_hi32_patch[3] = BPF_ALU64_REG(BPF_OR, 0, BPF_REG_AX);
+	for (i = 0; i < len; i++) {
+		int adj_idx = i + delta;
+		struct bpf_insn insn;
+
+		insn = insns[adj_idx];
+		if (!aux[adj_idx].zext_dst) {
+			u8 code, class;
+			u32 imm_rnd;
+
+			if (!rnd_hi32)
+				continue;
+
+			code = insn.code;
+			class = BPF_CLASS(code);
+			if (insn_no_def(&insn))
+				continue;
+
+			/* NOTE: arg "reg" (the fourth one) is only used for
+			 *       BPF_STX which has been ruled out in above
+			 *       check, it is safe to pass NULL here.
+			 */
+			if (is_reg64(env, &insn, insn.dst_reg, NULL, DST_OP)) {
+				if (class == BPF_LD &&
+				    BPF_MODE(code) == BPF_IMM)
+					i++;
+				continue;
+			}
+
+			/* ctx load could be transformed into wider load. */
+			if (class == BPF_LDX &&
+			    aux[adj_idx].ptr_type == PTR_TO_CTX)
+				continue;
+
+			imm_rnd = get_random_int();
+			rnd_hi32_patch[0] = insn;
+			rnd_hi32_patch[1].imm = imm_rnd;
+			rnd_hi32_patch[3].dst_reg = insn.dst_reg;
+			patch = rnd_hi32_patch;
+			patch_len = 4;
+			goto apply_patch_buffer;
+		}
+
+		if (!bpf_jit_needs_zext())
+			continue;
+
+		zext_patch[0] = insn;
+		zext_patch[1].dst_reg = insn.dst_reg;
+		zext_patch[1].src_reg = insn.dst_reg;
+		patch = zext_patch;
+		patch_len = 2;
+apply_patch_buffer:
+		new_prog = bpf_patch_insn_data(env, adj_idx, patch, patch_len);
+		if (!new_prog)
+			return -ENOMEM;
+		env->prog = new_prog;
+		insns = new_prog->insnsi;
+		aux = env->insn_aux_data;
+		delta += patch_len - 1;
+	}
+
+	return 0;
+}
+
+/* convert load instructions that access fields of a context type into a
+ * sequence of instructions that access fields of the underlying structure:
+ *     struct __sk_buff    -> struct sk_buff
+ *     struct bpf_sock_ops -> struct sock
+ */
+static int convert_ctx_accesses(struct bpf_verifier_env *env)
+{
+	const struct bpf_verifier_ops *ops = env->ops;
+	int i, cnt, size, ctx_field_size, delta = 0;
+	const int insn_cnt = env->prog->len;
+	struct bpf_insn insn_buf[16], *insn;
+	u32 target_size, size_default, off;
+	struct bpf_prog *new_prog;
+	enum bpf_access_type type;
+	bool is_narrower_load;
+
+	if (ops->gen_prologue || env->seen_direct_write) {
+		if (!ops->gen_prologue) {
+			verbose(env, "bpf verifier is misconfigured\n");
+			return -EINVAL;
+		}
+		cnt = ops->gen_prologue(insn_buf, env->seen_direct_write,
+					env->prog);
+		if (cnt >= ARRAY_SIZE(insn_buf)) {
+			verbose(env, "bpf verifier is misconfigured\n");
+			return -EINVAL;
+		} else if (cnt) {
+			new_prog = bpf_patch_insn_data(env, 0, insn_buf, cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			env->prog = new_prog;
+			delta += cnt - 1;
+		}
+	}
+
+	if (bpf_prog_is_dev_bound(env->prog->aux))
+		return 0;
+
+	insn = env->prog->insnsi + delta;
+
+	for (i = 0; i < insn_cnt; i++, insn++) {
+		bpf_convert_ctx_access_t convert_ctx_access;
+		bool ctx_access;
+
+		if (insn->code == (BPF_LDX | BPF_MEM | BPF_B) ||
+		    insn->code == (BPF_LDX | BPF_MEM | BPF_H) ||
+		    insn->code == (BPF_LDX | BPF_MEM | BPF_W) ||
+		    insn->code == (BPF_LDX | BPF_MEM | BPF_DW)) {
+			type = BPF_READ;
+			ctx_access = true;
+		} else if (insn->code == (BPF_STX | BPF_MEM | BPF_B) ||
+			   insn->code == (BPF_STX | BPF_MEM | BPF_H) ||
+			   insn->code == (BPF_STX | BPF_MEM | BPF_W) ||
+			   insn->code == (BPF_STX | BPF_MEM | BPF_DW) ||
+			   insn->code == (BPF_ST | BPF_MEM | BPF_B) ||
+			   insn->code == (BPF_ST | BPF_MEM | BPF_H) ||
+			   insn->code == (BPF_ST | BPF_MEM | BPF_W) ||
+			   insn->code == (BPF_ST | BPF_MEM | BPF_DW)) {
+			type = BPF_WRITE;
+			ctx_access = BPF_CLASS(insn->code) == BPF_STX;
+		} else {
+			continue;
+		}
+
+		if (type == BPF_WRITE &&
+		    env->insn_aux_data[i + delta].sanitize_stack_spill) {
+			struct bpf_insn patch[] = {
+				*insn,
+				BPF_ST_NOSPEC(),
+			};
+
+			cnt = ARRAY_SIZE(patch);
+			new_prog = bpf_patch_insn_data(env, i + delta, patch, cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			delta    += cnt - 1;
+			env->prog = new_prog;
+			insn      = new_prog->insnsi + i + delta;
+			continue;
+		}
+
+		if (!ctx_access)
+			continue;
+
+		switch (env->insn_aux_data[i + delta].ptr_type) {
+		case PTR_TO_CTX:
+			if (!ops->convert_ctx_access)
+				continue;
+			convert_ctx_access = ops->convert_ctx_access;
+			break;
+		case PTR_TO_SOCKET:
+		case PTR_TO_SOCK_COMMON:
+			convert_ctx_access = bpf_sock_convert_ctx_access;
+			break;
+		case PTR_TO_TCP_SOCK:
+			convert_ctx_access = bpf_tcp_sock_convert_ctx_access;
+			break;
+		case PTR_TO_XDP_SOCK:
+			convert_ctx_access = bpf_xdp_sock_convert_ctx_access;
+			break;
+		case PTR_TO_BTF_ID:
+			if (type == BPF_READ) {
+				insn->code = BPF_LDX | BPF_PROBE_MEM |
+					BPF_SIZE((insn)->code);
+				env->prog->aux->num_exentries++;
+			} else if (resolve_prog_type(env->prog) != BPF_PROG_TYPE_STRUCT_OPS) {
+				verbose(env, "Writes through BTF pointers are not allowed\n");
+				return -EINVAL;
+			}
+			continue;
+		default:
+			continue;
+		}
+
+		ctx_field_size = env->insn_aux_data[i + delta].ctx_field_size;
+		size = BPF_LDST_BYTES(insn);
+
+		/* If the read access is a narrower load of the field,
+		 * convert to a 4/8-byte load, to minimum program type specific
+		 * convert_ctx_access changes. If conversion is successful,
+		 * we will apply proper mask to the result.
+		 */
+		is_narrower_load = size < ctx_field_size;
+		size_default = bpf_ctx_off_adjust_machine(ctx_field_size);
+		off = insn->off;
+		if (is_narrower_load) {
+			u8 size_code;
+
+			if (type == BPF_WRITE) {
+				verbose(env, "bpf verifier narrow ctx access misconfigured\n");
+				return -EINVAL;
+			}
+
+			size_code = BPF_H;
+			if (ctx_field_size == 4)
+				size_code = BPF_W;
+			else if (ctx_field_size == 8)
+				size_code = BPF_DW;
+
+			insn->off = off & ~(size_default - 1);
+			insn->code = BPF_LDX | BPF_MEM | size_code;
+		}
+
+		target_size = 0;
+		cnt = convert_ctx_access(type, insn, insn_buf, env->prog,
+					 &target_size);
+		if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf) ||
+		    (ctx_field_size && !target_size)) {
+			verbose(env, "bpf verifier is misconfigured\n");
+			return -EINVAL;
+		}
+
+		if (is_narrower_load && size < target_size) {
+			u8 shift = bpf_ctx_narrow_access_offset(
+				off, size, size_default) * 8;
+			if (shift && cnt + 1 >= ARRAY_SIZE(insn_buf)) {
+				verbose(env, "bpf verifier narrow ctx load misconfigured\n");
+				return -EINVAL;
+			}
+			if (ctx_field_size <= 4) {
+				if (shift)
+					insn_buf[cnt++] = BPF_ALU32_IMM(BPF_RSH,
+									insn->dst_reg,
+									shift);
+				insn_buf[cnt++] = BPF_ALU32_IMM(BPF_AND, insn->dst_reg,
+								(1 << size * 8) - 1);
+			} else {
+				if (shift)
+					insn_buf[cnt++] = BPF_ALU64_IMM(BPF_RSH,
+									insn->dst_reg,
+									shift);
+				insn_buf[cnt++] = BPF_ALU32_IMM(BPF_AND, insn->dst_reg,
+								(1ULL << size * 8) - 1);
+			}
+		}
+
+		new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt);
+		if (!new_prog)
+			return -ENOMEM;
+
+		delta += cnt - 1;
+
+		/* keep walking new program and skip insns we just inserted */
+		env->prog = new_prog;
+		insn      = new_prog->insnsi + i + delta;
+	}
+
+	return 0;
+}
+
+static int jit_subprogs(struct bpf_verifier_env *env)
+{
+	struct bpf_prog *prog = env->prog, **func, *tmp;
+	int i, j, subprog_start, subprog_end = 0, len, subprog;
+	struct bpf_map *map_ptr;
+	struct bpf_insn *insn;
+	void *old_bpf_func;
+	int err, num_exentries;
+
+	if (env->subprog_cnt <= 1)
+		return 0;
+
+	for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
+		if (insn->code != (BPF_JMP | BPF_CALL) ||
+		    insn->src_reg != BPF_PSEUDO_CALL)
+			continue;
+		/* Upon error here we cannot fall back to interpreter but
+		 * need a hard reject of the program. Thus -EFAULT is
+		 * propagated in any case.
+		 */
+		subprog = find_subprog(env, i + insn->imm + 1);
+		if (subprog < 0) {
+			WARN_ONCE(1, "verifier bug. No program starts at insn %d\n",
+				  i + insn->imm + 1);
+			return -EFAULT;
+		}
+		/* temporarily remember subprog id inside insn instead of
+		 * aux_data, since next loop will split up all insns into funcs
+		 */
+		insn->off = subprog;
+		/* remember original imm in case JIT fails and fallback
+		 * to interpreter will be needed
+		 */
+		env->insn_aux_data[i].call_imm = insn->imm;
+		/* point imm to __bpf_call_base+1 from JITs point of view */
+		insn->imm = 1;
+	}
+
+	err = bpf_prog_alloc_jited_linfo(prog);
+	if (err)
+		goto out_undo_insn;
+
+	err = -ENOMEM;
+	func = kcalloc(env->subprog_cnt, sizeof(prog), GFP_KERNEL);
+	if (!func)
+		goto out_undo_insn;
+
+	for (i = 0; i < env->subprog_cnt; i++) {
+		subprog_start = subprog_end;
+		subprog_end = env->subprog_info[i + 1].start;
+
+		len = subprog_end - subprog_start;
+		/* BPF_PROG_RUN doesn't call subprogs directly,
+		 * hence main prog stats include the runtime of subprogs.
+		 * subprogs don't have IDs and not reachable via prog_get_next_id
+		 * func[i]->aux->stats will never be accessed and stays NULL
+		 */
+		func[i] = bpf_prog_alloc_no_stats(bpf_prog_size(len), GFP_USER);
+		if (!func[i])
+			goto out_free;
+		memcpy(func[i]->insnsi, &prog->insnsi[subprog_start],
+		       len * sizeof(struct bpf_insn));
+		func[i]->type = prog->type;
+		func[i]->len = len;
+		if (bpf_prog_calc_tag(func[i]))
+			goto out_free;
+		func[i]->is_func = 1;
+		func[i]->aux->func_idx = i;
+		/* Below members will be freed only at prog->aux */
+		func[i]->aux->btf = prog->aux->btf;
+		func[i]->aux->func_info = prog->aux->func_info;
+		func[i]->aux->func_info_cnt = prog->aux->func_info_cnt;
+		func[i]->aux->poke_tab = prog->aux->poke_tab;
+		func[i]->aux->size_poke_tab = prog->aux->size_poke_tab;
+
+		for (j = 0; j < prog->aux->size_poke_tab; j++) {
+			struct bpf_jit_poke_descriptor *poke;
+
+			poke = &prog->aux->poke_tab[j];
+			if (poke->insn_idx < subprog_end &&
+			    poke->insn_idx >= subprog_start)
+				poke->aux = func[i]->aux;
+		}
+
+		func[i]->aux->name[0] = 'F';
+		func[i]->aux->stack_depth = env->subprog_info[i].stack_depth;
+		func[i]->jit_requested = 1;
+		func[i]->aux->linfo = prog->aux->linfo;
+		func[i]->aux->nr_linfo = prog->aux->nr_linfo;
+		func[i]->aux->jited_linfo = prog->aux->jited_linfo;
+		func[i]->aux->linfo_idx = env->subprog_info[i].linfo_idx;
+		num_exentries = 0;
+		insn = func[i]->insnsi;
+		for (j = 0; j < func[i]->len; j++, insn++) {
+			if (BPF_CLASS(insn->code) == BPF_LDX &&
+			    BPF_MODE(insn->code) == BPF_PROBE_MEM)
+				num_exentries++;
+		}
+		func[i]->aux->num_exentries = num_exentries;
+		func[i]->aux->tail_call_reachable = env->subprog_info[i].tail_call_reachable;
+		func[i] = bpf_int_jit_compile(func[i]);
+		if (!func[i]->jited) {
+			err = -ENOTSUPP;
+			goto out_free;
+		}
+		cond_resched();
+	}
+
+	/* at this point all bpf functions were successfully JITed
+	 * now populate all bpf_calls with correct addresses and
+	 * run last pass of JIT
+	 */
+	for (i = 0; i < env->subprog_cnt; i++) {
+		insn = func[i]->insnsi;
+		for (j = 0; j < func[i]->len; j++, insn++) {
+			if (insn->code != (BPF_JMP | BPF_CALL) ||
+			    insn->src_reg != BPF_PSEUDO_CALL)
+				continue;
+			subprog = insn->off;
+			insn->imm = BPF_CAST_CALL(func[subprog]->bpf_func) -
+				    __bpf_call_base;
+		}
+
+		/* we use the aux data to keep a list of the start addresses
+		 * of the JITed images for each function in the program
+		 *
+		 * for some architectures, such as powerpc64, the imm field
+		 * might not be large enough to hold the offset of the start
+		 * address of the callee's JITed image from __bpf_call_base
+		 *
+		 * in such cases, we can lookup the start address of a callee
+		 * by using its subprog id, available from the off field of
+		 * the call instruction, as an index for this list
+		 */
+		func[i]->aux->func = func;
+		func[i]->aux->func_cnt = env->subprog_cnt;
+	}
+	for (i = 0; i < env->subprog_cnt; i++) {
+		old_bpf_func = func[i]->bpf_func;
+		tmp = bpf_int_jit_compile(func[i]);
+		if (tmp != func[i] || func[i]->bpf_func != old_bpf_func) {
+			verbose(env, "JIT doesn't support bpf-to-bpf calls\n");
+			err = -ENOTSUPP;
+			goto out_free;
+		}
+		cond_resched();
+	}
+
+	/* finally lock prog and jit images for all functions and
+	 * populate kallsysm
+	 */
+	for (i = 0; i < env->subprog_cnt; i++) {
+		bpf_prog_lock_ro(func[i]);
+		bpf_prog_kallsyms_add(func[i]);
+	}
+
+	/* Last step: make now unused interpreter insns from main
+	 * prog consistent for later dump requests, so they can
+	 * later look the same as if they were interpreted only.
+	 */
+	for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
+		if (insn->code != (BPF_JMP | BPF_CALL) ||
+		    insn->src_reg != BPF_PSEUDO_CALL)
+			continue;
+		insn->off = env->insn_aux_data[i].call_imm;
+		subprog = find_subprog(env, i + insn->off + 1);
+		insn->imm = subprog;
+	}
+
+	prog->jited = 1;
+	prog->bpf_func = func[0]->bpf_func;
+	prog->aux->func = func;
+	prog->aux->func_cnt = env->subprog_cnt;
+	bpf_prog_free_unused_jited_linfo(prog);
+	return 0;
+out_free:
+	/* We failed JIT'ing, so at this point we need to unregister poke
+	 * descriptors from subprogs, so that kernel is not attempting to
+	 * patch it anymore as we're freeing the subprog JIT memory.
+	 */
+	for (i = 0; i < prog->aux->size_poke_tab; i++) {
+		map_ptr = prog->aux->poke_tab[i].tail_call.map;
+		map_ptr->ops->map_poke_untrack(map_ptr, prog->aux);
+	}
+	/* At this point we're guaranteed that poke descriptors are not
+	 * live anymore. We can just unlink its descriptor table as it's
+	 * released with the main prog.
+	 */
+	for (i = 0; i < env->subprog_cnt; i++) {
+		if (!func[i])
+			continue;
+		func[i]->aux->poke_tab = NULL;
+		bpf_jit_free(func[i]);
+	}
+	kfree(func);
+out_undo_insn:
+	/* cleanup main prog to be interpreted */
+	prog->jit_requested = 0;
+	for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
+		if (insn->code != (BPF_JMP | BPF_CALL) ||
+		    insn->src_reg != BPF_PSEUDO_CALL)
+			continue;
+		insn->off = 0;
+		insn->imm = env->insn_aux_data[i].call_imm;
+	}
+	bpf_prog_free_jited_linfo(prog);
+	return err;
+}
+
+static int fixup_call_args(struct bpf_verifier_env *env)
+{
+#ifndef CONFIG_BPF_JIT_ALWAYS_ON
+	struct bpf_prog *prog = env->prog;
+	struct bpf_insn *insn = prog->insnsi;
+	int i, depth;
+#endif
+	int err = 0;
+
+	if (env->prog->jit_requested &&
+	    !bpf_prog_is_dev_bound(env->prog->aux)) {
+		err = jit_subprogs(env);
+		if (err == 0)
+			return 0;
+		if (err == -EFAULT)
+			return err;
+	}
+#ifndef CONFIG_BPF_JIT_ALWAYS_ON
+	if (env->subprog_cnt > 1 && env->prog->aux->tail_call_reachable) {
+		/* When JIT fails the progs with bpf2bpf calls and tail_calls
+		 * have to be rejected, since interpreter doesn't support them yet.
+		 */
+		verbose(env, "tail_calls are not allowed in non-JITed programs with bpf-to-bpf calls\n");
+		return -EINVAL;
+	}
+	for (i = 0; i < prog->len; i++, insn++) {
+		if (insn->code != (BPF_JMP | BPF_CALL) ||
+		    insn->src_reg != BPF_PSEUDO_CALL)
+			continue;
+		depth = get_callee_stack_depth(env, insn, i);
+		if (depth < 0)
+			return depth;
+		bpf_patch_call_args(insn, depth);
+	}
+	err = 0;
+#endif
+	return err;
+}
+
+/* fixup insn->imm field of bpf_call instructions
+ * and inline eligible helpers as explicit sequence of BPF instructions
+ *
+ * this function is called after eBPF program passed verification
+ */
+static int fixup_bpf_calls(struct bpf_verifier_env *env)
+{
+	struct bpf_prog *prog = env->prog;
+	bool expect_blinding = bpf_jit_blinding_enabled(prog);
+	struct bpf_insn *insn = prog->insnsi;
+	const struct bpf_func_proto *fn;
+	const int insn_cnt = prog->len;
+	const struct bpf_map_ops *ops;
+	struct bpf_insn_aux_data *aux;
+	struct bpf_insn insn_buf[16];
+	struct bpf_prog *new_prog;
+	struct bpf_map *map_ptr;
+	int i, ret, cnt, delta = 0;
+
+	for (i = 0; i < insn_cnt; i++, insn++) {
+		if (insn->code == (BPF_ALU64 | BPF_MOD | BPF_X) ||
+		    insn->code == (BPF_ALU64 | BPF_DIV | BPF_X) ||
+		    insn->code == (BPF_ALU | BPF_MOD | BPF_X) ||
+		    insn->code == (BPF_ALU | BPF_DIV | BPF_X)) {
+			bool is64 = BPF_CLASS(insn->code) == BPF_ALU64;
+			bool isdiv = BPF_OP(insn->code) == BPF_DIV;
+			struct bpf_insn *patchlet;
+			struct bpf_insn chk_and_div[] = {
+				/* [R,W]x div 0 -> 0 */
+				BPF_RAW_INSN((is64 ? BPF_JMP : BPF_JMP32) |
+					     BPF_JNE | BPF_K, insn->src_reg,
+					     0, 2, 0),
+				BPF_ALU32_REG(BPF_XOR, insn->dst_reg, insn->dst_reg),
+				BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+				*insn,
+			};
+			struct bpf_insn chk_and_mod[] = {
+				/* [R,W]x mod 0 -> [R,W]x */
+				BPF_RAW_INSN((is64 ? BPF_JMP : BPF_JMP32) |
+					     BPF_JEQ | BPF_K, insn->src_reg,
+					     0, 1 + (is64 ? 0 : 1), 0),
+				*insn,
+				BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+				BPF_MOV32_REG(insn->dst_reg, insn->dst_reg),
+			};
+
+			patchlet = isdiv ? chk_and_div : chk_and_mod;
+			cnt = isdiv ? ARRAY_SIZE(chk_and_div) :
+				      ARRAY_SIZE(chk_and_mod) - (is64 ? 2 : 0);
+
+			new_prog = bpf_patch_insn_data(env, i + delta, patchlet, cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			delta    += cnt - 1;
+			env->prog = prog = new_prog;
+			insn      = new_prog->insnsi + i + delta;
+			continue;
+		}
+
+		if (BPF_CLASS(insn->code) == BPF_LD &&
+		    (BPF_MODE(insn->code) == BPF_ABS ||
+		     BPF_MODE(insn->code) == BPF_IND)) {
+			cnt = env->ops->gen_ld_abs(insn, insn_buf);
+			if (cnt == 0 || cnt >= ARRAY_SIZE(insn_buf)) {
+				verbose(env, "bpf verifier is misconfigured\n");
+				return -EINVAL;
+			}
+
+			new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			delta    += cnt - 1;
+			env->prog = prog = new_prog;
+			insn      = new_prog->insnsi + i + delta;
+			continue;
+		}
+
+		if (insn->code == (BPF_ALU64 | BPF_ADD | BPF_X) ||
+		    insn->code == (BPF_ALU64 | BPF_SUB | BPF_X)) {
+			const u8 code_add = BPF_ALU64 | BPF_ADD | BPF_X;
+			const u8 code_sub = BPF_ALU64 | BPF_SUB | BPF_X;
+			struct bpf_insn insn_buf[16];
+			struct bpf_insn *patch = &insn_buf[0];
+			bool issrc, isneg, isimm;
+			u32 off_reg;
+
+			aux = &env->insn_aux_data[i + delta];
+			if (!aux->alu_state ||
+			    aux->alu_state == BPF_ALU_NON_POINTER)
+				continue;
+
+			isneg = aux->alu_state & BPF_ALU_NEG_VALUE;
+			issrc = (aux->alu_state & BPF_ALU_SANITIZE) ==
+				BPF_ALU_SANITIZE_SRC;
+			isimm = aux->alu_state & BPF_ALU_IMMEDIATE;
+
+			off_reg = issrc ? insn->src_reg : insn->dst_reg;
+			if (isimm) {
+				*patch++ = BPF_MOV32_IMM(BPF_REG_AX, aux->alu_limit);
+			} else {
+				if (isneg)
+					*patch++ = BPF_ALU64_IMM(BPF_MUL, off_reg, -1);
+				*patch++ = BPF_MOV32_IMM(BPF_REG_AX, aux->alu_limit);
+				*patch++ = BPF_ALU64_REG(BPF_SUB, BPF_REG_AX, off_reg);
+				*patch++ = BPF_ALU64_REG(BPF_OR, BPF_REG_AX, off_reg);
+				*patch++ = BPF_ALU64_IMM(BPF_NEG, BPF_REG_AX, 0);
+				*patch++ = BPF_ALU64_IMM(BPF_ARSH, BPF_REG_AX, 63);
+				*patch++ = BPF_ALU64_REG(BPF_AND, BPF_REG_AX, off_reg);
+			}
+			if (!issrc)
+				*patch++ = BPF_MOV64_REG(insn->dst_reg, insn->src_reg);
+			insn->src_reg = BPF_REG_AX;
+			if (isneg)
+				insn->code = insn->code == code_add ?
+					     code_sub : code_add;
+			*patch++ = *insn;
+			if (issrc && isneg && !isimm)
+				*patch++ = BPF_ALU64_IMM(BPF_MUL, off_reg, -1);
+			cnt = patch - insn_buf;
+
+			new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			delta    += cnt - 1;
+			env->prog = prog = new_prog;
+			insn      = new_prog->insnsi + i + delta;
+			continue;
+		}
+
+		if (insn->code != (BPF_JMP | BPF_CALL))
+			continue;
+		if (insn->src_reg == BPF_PSEUDO_CALL)
+			continue;
+
+		if (insn->imm == BPF_FUNC_get_route_realm)
+			prog->dst_needed = 1;
+		if (insn->imm == BPF_FUNC_get_prandom_u32)
+			bpf_user_rnd_init_once();
+		if (insn->imm == BPF_FUNC_override_return)
+			prog->kprobe_override = 1;
+		if (insn->imm == BPF_FUNC_tail_call) {
+			/* If we tail call into other programs, we
+			 * cannot make any assumptions since they can
+			 * be replaced dynamically during runtime in
+			 * the program array.
+			 */
+			prog->cb_access = 1;
+			if (!allow_tail_call_in_subprogs(env))
+				prog->aux->stack_depth = MAX_BPF_STACK;
+			prog->aux->max_pkt_offset = MAX_PACKET_OFF;
+
+			/* mark bpf_tail_call as different opcode to avoid
+			 * conditional branch in the interpeter for every normal
+			 * call and to prevent accidental JITing by JIT compiler
+			 * that doesn't support bpf_tail_call yet
+			 */
+			insn->imm = 0;
+			insn->code = BPF_JMP | BPF_TAIL_CALL;
+
+			aux = &env->insn_aux_data[i + delta];
+			if (env->bpf_capable && !expect_blinding &&
+			    prog->jit_requested &&
+			    !bpf_map_key_poisoned(aux) &&
+			    !bpf_map_ptr_poisoned(aux) &&
+			    !bpf_map_ptr_unpriv(aux)) {
+				struct bpf_jit_poke_descriptor desc = {
+					.reason = BPF_POKE_REASON_TAIL_CALL,
+					.tail_call.map = BPF_MAP_PTR(aux->map_ptr_state),
+					.tail_call.key = bpf_map_key_immediate(aux),
+					.insn_idx = i + delta,
+				};
+
+				ret = bpf_jit_add_poke_descriptor(prog, &desc);
+				if (ret < 0) {
+					verbose(env, "adding tail call poke descriptor failed\n");
+					return ret;
+				}
+
+				insn->imm = ret + 1;
+				continue;
+			}
+
+			if (!bpf_map_ptr_unpriv(aux))
+				continue;
+
+			/* instead of changing every JIT dealing with tail_call
+			 * emit two extra insns:
+			 * if (index >= max_entries) goto out;
+			 * index &= array->index_mask;
+			 * to avoid out-of-bounds cpu speculation
+			 */
+			if (bpf_map_ptr_poisoned(aux)) {
+				verbose(env, "tail_call abusing map_ptr\n");
+				return -EINVAL;
+			}
+
+			map_ptr = BPF_MAP_PTR(aux->map_ptr_state);
+			insn_buf[0] = BPF_JMP_IMM(BPF_JGE, BPF_REG_3,
+						  map_ptr->max_entries, 2);
+			insn_buf[1] = BPF_ALU32_IMM(BPF_AND, BPF_REG_3,
+						    container_of(map_ptr,
+								 struct bpf_array,
+								 map)->index_mask);
+			insn_buf[2] = *insn;
+			cnt = 3;
+			new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			delta    += cnt - 1;
+			env->prog = prog = new_prog;
+			insn      = new_prog->insnsi + i + delta;
+			continue;
+		}
+
+		/* BPF_EMIT_CALL() assumptions in some of the map_gen_lookup
+		 * and other inlining handlers are currently limited to 64 bit
+		 * only.
+		 */
+		if (prog->jit_requested && BITS_PER_LONG == 64 &&
+		    (insn->imm == BPF_FUNC_map_lookup_elem ||
+		     insn->imm == BPF_FUNC_map_update_elem ||
+		     insn->imm == BPF_FUNC_map_delete_elem ||
+		     insn->imm == BPF_FUNC_map_push_elem   ||
+		     insn->imm == BPF_FUNC_map_pop_elem    ||
+		     insn->imm == BPF_FUNC_map_peek_elem)) {
+			aux = &env->insn_aux_data[i + delta];
+			if (bpf_map_ptr_poisoned(aux))
+				goto patch_call_imm;
+
+			map_ptr = BPF_MAP_PTR(aux->map_ptr_state);
+			ops = map_ptr->ops;
+			if (insn->imm == BPF_FUNC_map_lookup_elem &&
+			    ops->map_gen_lookup) {
+				cnt = ops->map_gen_lookup(map_ptr, insn_buf);
+				if (cnt == -EOPNOTSUPP)
+					goto patch_map_ops_generic;
+				if (cnt <= 0 || cnt >= ARRAY_SIZE(insn_buf)) {
+					verbose(env, "bpf verifier is misconfigured\n");
+					return -EINVAL;
+				}
+
+				new_prog = bpf_patch_insn_data(env, i + delta,
+							       insn_buf, cnt);
+				if (!new_prog)
+					return -ENOMEM;
+
+				delta    += cnt - 1;
+				env->prog = prog = new_prog;
+				insn      = new_prog->insnsi + i + delta;
+				continue;
+			}
+
+			BUILD_BUG_ON(!__same_type(ops->map_lookup_elem,
+				     (void *(*)(struct bpf_map *map, void *key))NULL));
+			BUILD_BUG_ON(!__same_type(ops->map_delete_elem,
+				     (int (*)(struct bpf_map *map, void *key))NULL));
+			BUILD_BUG_ON(!__same_type(ops->map_update_elem,
+				     (int (*)(struct bpf_map *map, void *key, void *value,
+					      u64 flags))NULL));
+			BUILD_BUG_ON(!__same_type(ops->map_push_elem,
+				     (int (*)(struct bpf_map *map, void *value,
+					      u64 flags))NULL));
+			BUILD_BUG_ON(!__same_type(ops->map_pop_elem,
+				     (int (*)(struct bpf_map *map, void *value))NULL));
+			BUILD_BUG_ON(!__same_type(ops->map_peek_elem,
+				     (int (*)(struct bpf_map *map, void *value))NULL));
+patch_map_ops_generic:
+			switch (insn->imm) {
+			case BPF_FUNC_map_lookup_elem:
+				insn->imm = BPF_CAST_CALL(ops->map_lookup_elem) -
+					    __bpf_call_base;
+				continue;
+			case BPF_FUNC_map_update_elem:
+				insn->imm = BPF_CAST_CALL(ops->map_update_elem) -
+					    __bpf_call_base;
+				continue;
+			case BPF_FUNC_map_delete_elem:
+				insn->imm = BPF_CAST_CALL(ops->map_delete_elem) -
+					    __bpf_call_base;
+				continue;
+			case BPF_FUNC_map_push_elem:
+				insn->imm = BPF_CAST_CALL(ops->map_push_elem) -
+					    __bpf_call_base;
+				continue;
+			case BPF_FUNC_map_pop_elem:
+				insn->imm = BPF_CAST_CALL(ops->map_pop_elem) -
+					    __bpf_call_base;
+				continue;
+			case BPF_FUNC_map_peek_elem:
+				insn->imm = BPF_CAST_CALL(ops->map_peek_elem) -
+					    __bpf_call_base;
+				continue;
+			}
+
+			goto patch_call_imm;
+		}
+
+		if (prog->jit_requested && BITS_PER_LONG == 64 &&
+		    insn->imm == BPF_FUNC_jiffies64) {
+			struct bpf_insn ld_jiffies_addr[2] = {
+				BPF_LD_IMM64(BPF_REG_0,
+					     (unsigned long)&jiffies),
+			};
+
+			insn_buf[0] = ld_jiffies_addr[0];
+			insn_buf[1] = ld_jiffies_addr[1];
+			insn_buf[2] = BPF_LDX_MEM(BPF_DW, BPF_REG_0,
+						  BPF_REG_0, 0);
+			cnt = 3;
+
+			new_prog = bpf_patch_insn_data(env, i + delta, insn_buf,
+						       cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			delta    += cnt - 1;
+			env->prog = prog = new_prog;
+			insn      = new_prog->insnsi + i + delta;
+			continue;
+		}
+
+patch_call_imm:
+		fn = env->ops->get_func_proto(insn->imm, env->prog);
+		/* all functions that have prototype and verifier allowed
+		 * programs to call them, must be real in-kernel functions
+		 */
+		if (!fn->func) {
+			verbose(env,
+				"kernel subsystem misconfigured func %s#%d\n",
+				func_id_name(insn->imm), insn->imm);
+			return -EFAULT;
+		}
+		insn->imm = fn->func - __bpf_call_base;
+	}
+
+	/* Since poke tab is now finalized, publish aux to tracker. */
+	for (i = 0; i < prog->aux->size_poke_tab; i++) {
+		map_ptr = prog->aux->poke_tab[i].tail_call.map;
+		if (!map_ptr->ops->map_poke_track ||
+		    !map_ptr->ops->map_poke_untrack ||
+		    !map_ptr->ops->map_poke_run) {
+			verbose(env, "bpf verifier is misconfigured\n");
+			return -EINVAL;
+		}
+
+		ret = map_ptr->ops->map_poke_track(map_ptr, prog->aux);
+		if (ret < 0) {
+			verbose(env, "tracking tail call prog failed\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void free_states(struct bpf_verifier_env *env)
+{
+	struct bpf_verifier_state_list *sl, *sln;
+	int i;
+
+	sl = env->free_list;
+	while (sl) {
+		sln = sl->next;
+		free_verifier_state(&sl->state, false);
+		kfree(sl);
+		sl = sln;
+	}
+	env->free_list = NULL;
+
+	if (!env->explored_states)
+		return;
+
+	for (i = 0; i < state_htab_size(env); i++) {
+		sl = env->explored_states[i];
+
+		while (sl) {
+			sln = sl->next;
+			free_verifier_state(&sl->state, false);
+			kfree(sl);
+			sl = sln;
+		}
+		env->explored_states[i] = NULL;
+	}
+}
+
+static int do_check_common(struct bpf_verifier_env *env, int subprog)
+{
+	bool pop_log = !(env->log.level & BPF_LOG_LEVEL2);
+	struct bpf_verifier_state *state;
+	struct bpf_reg_state *regs;
+	int ret, i;
+
+	env->prev_linfo = NULL;
+	env->pass_cnt++;
+
+	state = kzalloc(sizeof(struct bpf_verifier_state), GFP_KERNEL);
+	if (!state)
+		return -ENOMEM;
+	state->curframe = 0;
+	state->speculative = false;
+	state->branches = 1;
+	state->frame[0] = kzalloc(sizeof(struct bpf_func_state), GFP_KERNEL);
+	if (!state->frame[0]) {
+		kfree(state);
+		return -ENOMEM;
+	}
+	env->cur_state = state;
+	init_func_state(env, state->frame[0],
+			BPF_MAIN_FUNC /* callsite */,
+			0 /* frameno */,
+			subprog);
+
+	state->first_insn_idx = env->subprog_info[subprog].start;
+	state->last_insn_idx = -1;
+
+	regs = state->frame[state->curframe]->regs;
+	if (subprog || env->prog->type == BPF_PROG_TYPE_EXT) {
+		ret = btf_prepare_func_args(env, subprog, regs);
+		if (ret)
+			goto out;
+		for (i = BPF_REG_1; i <= BPF_REG_5; i++) {
+			if (regs[i].type == PTR_TO_CTX)
+				mark_reg_known_zero(env, regs, i);
+			else if (regs[i].type == SCALAR_VALUE)
+				mark_reg_unknown(env, regs, i);
+		}
+	} else {
+		/* 1st arg to a function */
+		regs[BPF_REG_1].type = PTR_TO_CTX;
+		mark_reg_known_zero(env, regs, BPF_REG_1);
+		ret = btf_check_func_arg_match(env, subprog, regs);
+		if (ret == -EFAULT)
+			/* unlikely verifier bug. abort.
+			 * ret == 0 and ret < 0 are sadly acceptable for
+			 * main() function due to backward compatibility.
+			 * Like socket filter program may be written as:
+			 * int bpf_prog(struct pt_regs *ctx)
+			 * and never dereference that ctx in the program.
+			 * 'struct pt_regs' is a type mismatch for socket
+			 * filter that should be using 'struct __sk_buff'.
+			 */
+			goto out;
+	}
+
+	ret = do_check(env);
+out:
+	/* check for NULL is necessary, since cur_state can be freed inside
+	 * do_check() under memory pressure.
+	 */
+	if (env->cur_state) {
+		free_verifier_state(env->cur_state, true);
+		env->cur_state = NULL;
+	}
+	while (!pop_stack(env, NULL, NULL, false));
+	if (!ret && pop_log)
+		bpf_vlog_reset(&env->log, 0);
+	free_states(env);
+	return ret;
+}
+
+/* Verify all global functions in a BPF program one by one based on their BTF.
+ * All global functions must pass verification. Otherwise the whole program is rejected.
+ * Consider:
+ * int bar(int);
+ * int foo(int f)
+ * {
+ *    return bar(f);
+ * }
+ * int bar(int b)
+ * {
+ *    ...
+ * }
+ * foo() will be verified first for R1=any_scalar_value. During verification it
+ * will be assumed that bar() already verified successfully and call to bar()
+ * from foo() will be checked for type match only. Later bar() will be verified
+ * independently to check that it's safe for R1=any_scalar_value.
+ */
+static int do_check_subprogs(struct bpf_verifier_env *env)
+{
+	struct bpf_prog_aux *aux = env->prog->aux;
+	int i, ret;
+
+	if (!aux->func_info)
+		return 0;
+
+	for (i = 1; i < env->subprog_cnt; i++) {
+		if (aux->func_info_aux[i].linkage != BTF_FUNC_GLOBAL)
+			continue;
+		env->insn_idx = env->subprog_info[i].start;
+		WARN_ON_ONCE(env->insn_idx == 0);
+		ret = do_check_common(env, i);
+		if (ret) {
+			return ret;
+		} else if (env->log.level & BPF_LOG_LEVEL) {
+			verbose(env,
+				"Func#%d is safe for any args that match its prototype\n",
+				i);
+		}
+	}
+	return 0;
+}
+
+static int do_check_main(struct bpf_verifier_env *env)
+{
+	int ret;
+
+	env->insn_idx = 0;
+	ret = do_check_common(env, 0);
+	if (!ret)
+		env->prog->aux->stack_depth = env->subprog_info[0].stack_depth;
+	return ret;
+}
+
+
+static void print_verification_stats(struct bpf_verifier_env *env)
+{
+	int i;
+
+	if (env->log.level & BPF_LOG_STATS) {
+		verbose(env, "verification time %lld usec\n",
+			div_u64(env->verification_time, 1000));
+		verbose(env, "stack depth ");
+		for (i = 0; i < env->subprog_cnt; i++) {
+			u32 depth = env->subprog_info[i].stack_depth;
+
+			verbose(env, "%d", depth);
+			if (i + 1 < env->subprog_cnt)
+				verbose(env, "+");
+		}
+		verbose(env, "\n");
+	}
+	verbose(env, "processed %d insns (limit %d) max_states_per_insn %d "
+		"total_states %d peak_states %d mark_read %d\n",
+		env->insn_processed, BPF_COMPLEXITY_LIMIT_INSNS,
+		env->max_states_per_insn, env->total_states,
+		env->peak_states, env->longest_mark_read_walk);
+}
+
+static int check_struct_ops_btf_id(struct bpf_verifier_env *env)
+{
+	const struct btf_type *t, *func_proto;
+	const struct bpf_struct_ops *st_ops;
+	const struct btf_member *member;
+	struct bpf_prog *prog = env->prog;
+	u32 btf_id, member_idx;
+	const char *mname;
+
+	if (!prog->gpl_compatible) {
+		verbose(env, "struct ops programs must have a GPL compatible license\n");
+		return -EINVAL;
+	}
+
+	btf_id = prog->aux->attach_btf_id;
+	st_ops = bpf_struct_ops_find(btf_id);
+	if (!st_ops) {
+		verbose(env, "attach_btf_id %u is not a supported struct\n",
+			btf_id);
+		return -ENOTSUPP;
+	}
+
+	t = st_ops->type;
+	member_idx = prog->expected_attach_type;
+	if (member_idx >= btf_type_vlen(t)) {
+		verbose(env, "attach to invalid member idx %u of struct %s\n",
+			member_idx, st_ops->name);
+		return -EINVAL;
+	}
+
+	member = &btf_type_member(t)[member_idx];
+	mname = btf_name_by_offset(btf_vmlinux, member->name_off);
+	func_proto = btf_type_resolve_func_ptr(btf_vmlinux, member->type,
+					       NULL);
+	if (!func_proto) {
+		verbose(env, "attach to invalid member %s(@idx %u) of struct %s\n",
+			mname, member_idx, st_ops->name);
+		return -EINVAL;
+	}
+
+	if (st_ops->check_member) {
+		int err = st_ops->check_member(t, member);
+
+		if (err) {
+			verbose(env, "attach to unsupported member %s of struct %s\n",
+				mname, st_ops->name);
+			return err;
+		}
+	}
+
+	prog->aux->attach_func_proto = func_proto;
+	prog->aux->attach_func_name = mname;
+	env->ops = st_ops->verifier_ops;
+
+	return 0;
+}
+#define SECURITY_PREFIX "security_"
+
+static int check_attach_modify_return(unsigned long addr, const char *func_name)
+{
+	if (within_error_injection_list(addr) ||
+	    !strncmp(SECURITY_PREFIX, func_name, sizeof(SECURITY_PREFIX) - 1))
+		return 0;
+
+	return -EINVAL;
+}
+
+/* non exhaustive list of sleepable bpf_lsm_*() functions */
+BTF_SET_START(btf_sleepable_lsm_hooks)
+#ifdef CONFIG_BPF_LSM
+BTF_ID(func, bpf_lsm_bprm_committed_creds)
+#else
+BTF_ID_UNUSED
+#endif
+BTF_SET_END(btf_sleepable_lsm_hooks)
+
+static int check_sleepable_lsm_hook(u32 btf_id)
+{
+	return btf_id_set_contains(&btf_sleepable_lsm_hooks, btf_id);
+}
+
+/* list of non-sleepable functions that are otherwise on
+ * ALLOW_ERROR_INJECTION list
+ */
+BTF_SET_START(btf_non_sleepable_error_inject)
+/* Three functions below can be called from sleepable and non-sleepable context.
+ * Assume non-sleepable from bpf safety point of view.
+ */
+BTF_ID(func, __add_to_page_cache_locked)
+BTF_ID(func, should_fail_alloc_page)
+BTF_ID(func, should_failslab)
+BTF_SET_END(btf_non_sleepable_error_inject)
+
+static int check_non_sleepable_error_inject(u32 btf_id)
+{
+	return btf_id_set_contains(&btf_non_sleepable_error_inject, btf_id);
+}
+
+int bpf_check_attach_target(struct bpf_verifier_log *log,
+			    const struct bpf_prog *prog,
+			    const struct bpf_prog *tgt_prog,
+			    u32 btf_id,
+			    struct bpf_attach_target_info *tgt_info)
+{
+	bool prog_extension = prog->type == BPF_PROG_TYPE_EXT;
+	const char prefix[] = "btf_trace_";
+	int ret = 0, subprog = -1, i;
+	const struct btf_type *t;
+	bool conservative = true;
+	const char *tname;
+	struct btf *btf;
+	long addr = 0;
+
+	if (!btf_id) {
+		bpf_log(log, "Tracing programs must provide btf_id\n");
+		return -EINVAL;
+	}
+	btf = tgt_prog ? tgt_prog->aux->btf : btf_vmlinux;
+	if (!btf) {
+		bpf_log(log,
+			"FENTRY/FEXIT program can only be attached to another program annotated with BTF\n");
+		return -EINVAL;
+	}
+	t = btf_type_by_id(btf, btf_id);
+	if (!t) {
+		bpf_log(log, "attach_btf_id %u is invalid\n", btf_id);
+		return -EINVAL;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+	if (!tname) {
+		bpf_log(log, "attach_btf_id %u doesn't have a name\n", btf_id);
+		return -EINVAL;
+	}
+	if (tgt_prog) {
+		struct bpf_prog_aux *aux = tgt_prog->aux;
+
+		for (i = 0; i < aux->func_info_cnt; i++)
+			if (aux->func_info[i].type_id == btf_id) {
+				subprog = i;
+				break;
+			}
+		if (subprog == -1) {
+			bpf_log(log, "Subprog %s doesn't exist\n", tname);
+			return -EINVAL;
+		}
+		conservative = aux->func_info_aux[subprog].unreliable;
+		if (prog_extension) {
+			if (conservative) {
+				bpf_log(log,
+					"Cannot replace static functions\n");
+				return -EINVAL;
+			}
+			if (!prog->jit_requested) {
+				bpf_log(log,
+					"Extension programs should be JITed\n");
+				return -EINVAL;
+			}
+		}
+		if (!tgt_prog->jited) {
+			bpf_log(log, "Can attach to only JITed progs\n");
+			return -EINVAL;
+		}
+		if (tgt_prog->type == prog->type) {
+			/* Cannot fentry/fexit another fentry/fexit program.
+			 * Cannot attach program extension to another extension.
+			 * It's ok to attach fentry/fexit to extension program.
+			 */
+			bpf_log(log, "Cannot recursively attach\n");
+			return -EINVAL;
+		}
+		if (tgt_prog->type == BPF_PROG_TYPE_TRACING &&
+		    prog_extension &&
+		    (tgt_prog->expected_attach_type == BPF_TRACE_FENTRY ||
+		     tgt_prog->expected_attach_type == BPF_TRACE_FEXIT)) {
+			/* Program extensions can extend all program types
+			 * except fentry/fexit. The reason is the following.
+			 * The fentry/fexit programs are used for performance
+			 * analysis, stats and can be attached to any program
+			 * type except themselves. When extension program is
+			 * replacing XDP function it is necessary to allow
+			 * performance analysis of all functions. Both original
+			 * XDP program and its program extension. Hence
+			 * attaching fentry/fexit to BPF_PROG_TYPE_EXT is
+			 * allowed. If extending of fentry/fexit was allowed it
+			 * would be possible to create long call chain
+			 * fentry->extension->fentry->extension beyond
+			 * reasonable stack size. Hence extending fentry is not
+			 * allowed.
+			 */
+			bpf_log(log, "Cannot extend fentry/fexit\n");
+			return -EINVAL;
+		}
+	} else {
+		if (prog_extension) {
+			bpf_log(log, "Cannot replace kernel functions\n");
+			return -EINVAL;
+		}
+	}
+
+	switch (prog->expected_attach_type) {
+	case BPF_TRACE_RAW_TP:
+		if (tgt_prog) {
+			bpf_log(log,
+				"Only FENTRY/FEXIT progs are attachable to another BPF prog\n");
+			return -EINVAL;
+		}
+		if (!btf_type_is_typedef(t)) {
+			bpf_log(log, "attach_btf_id %u is not a typedef\n",
+				btf_id);
+			return -EINVAL;
+		}
+		if (strncmp(prefix, tname, sizeof(prefix) - 1)) {
+			bpf_log(log, "attach_btf_id %u points to wrong type name %s\n",
+				btf_id, tname);
+			return -EINVAL;
+		}
+		tname += sizeof(prefix) - 1;
+		t = btf_type_by_id(btf, t->type);
+		if (!btf_type_is_ptr(t))
+			/* should never happen in valid vmlinux build */
+			return -EINVAL;
+		t = btf_type_by_id(btf, t->type);
+		if (!btf_type_is_func_proto(t))
+			/* should never happen in valid vmlinux build */
+			return -EINVAL;
+
+		break;
+	case BPF_TRACE_ITER:
+		if (!btf_type_is_func(t)) {
+			bpf_log(log, "attach_btf_id %u is not a function\n",
+				btf_id);
+			return -EINVAL;
+		}
+		t = btf_type_by_id(btf, t->type);
+		if (!btf_type_is_func_proto(t))
+			return -EINVAL;
+		ret = btf_distill_func_proto(log, btf, t, tname, &tgt_info->fmodel);
+		if (ret)
+			return ret;
+		break;
+	default:
+		if (!prog_extension)
+			return -EINVAL;
+		fallthrough;
+	case BPF_MODIFY_RETURN:
+	case BPF_LSM_MAC:
+	case BPF_TRACE_FENTRY:
+	case BPF_TRACE_FEXIT:
+		if (!btf_type_is_func(t)) {
+			bpf_log(log, "attach_btf_id %u is not a function\n",
+				btf_id);
+			return -EINVAL;
+		}
+		if (prog_extension &&
+		    btf_check_type_match(log, prog, btf, t))
+			return -EINVAL;
+		t = btf_type_by_id(btf, t->type);
+		if (!btf_type_is_func_proto(t))
+			return -EINVAL;
+
+		if ((prog->aux->saved_dst_prog_type || prog->aux->saved_dst_attach_type) &&
+		    (!tgt_prog || prog->aux->saved_dst_prog_type != tgt_prog->type ||
+		     prog->aux->saved_dst_attach_type != tgt_prog->expected_attach_type))
+			return -EINVAL;
+
+		if (tgt_prog && conservative)
+			t = NULL;
+
+		ret = btf_distill_func_proto(log, btf, t, tname, &tgt_info->fmodel);
+		if (ret < 0)
+			return ret;
+
+		if (tgt_prog) {
+			if (subprog == 0)
+				addr = (long) tgt_prog->bpf_func;
+			else
+				addr = (long) tgt_prog->aux->func[subprog]->bpf_func;
+		} else {
+			addr = kallsyms_lookup_name(tname);
+			if (!addr) {
+				bpf_log(log,
+					"The address of function %s cannot be found\n",
+					tname);
+				return -ENOENT;
+			}
+		}
+
+		if (prog->aux->sleepable) {
+			ret = -EINVAL;
+			switch (prog->type) {
+			case BPF_PROG_TYPE_TRACING:
+				/* fentry/fexit/fmod_ret progs can be sleepable only if they are
+				 * attached to ALLOW_ERROR_INJECTION and are not in denylist.
+				 */
+				if (!check_non_sleepable_error_inject(btf_id) &&
+				    within_error_injection_list(addr))
+					ret = 0;
+				break;
+			case BPF_PROG_TYPE_LSM:
+				/* LSM progs check that they are attached to bpf_lsm_*() funcs.
+				 * Only some of them are sleepable.
+				 */
+				if (check_sleepable_lsm_hook(btf_id))
+					ret = 0;
+				break;
+			default:
+				break;
+			}
+			if (ret) {
+				bpf_log(log, "%s is not sleepable\n", tname);
+				return ret;
+			}
+		} else if (prog->expected_attach_type == BPF_MODIFY_RETURN) {
+			if (tgt_prog) {
+				bpf_log(log, "can't modify return codes of BPF programs\n");
+				return -EINVAL;
+			}
+			ret = check_attach_modify_return(addr, tname);
+			if (ret) {
+				bpf_log(log, "%s() is not modifiable\n", tname);
+				return ret;
+			}
+		}
+
+		break;
+	}
+	tgt_info->tgt_addr = addr;
+	tgt_info->tgt_name = tname;
+	tgt_info->tgt_type = t;
+	return 0;
+}
+
+static int check_attach_btf_id(struct bpf_verifier_env *env)
+{
+	struct bpf_prog *prog = env->prog;
+	struct bpf_prog *tgt_prog = prog->aux->dst_prog;
+	struct bpf_attach_target_info tgt_info = {};
+	u32 btf_id = prog->aux->attach_btf_id;
+	struct bpf_trampoline *tr;
+	int ret;
+	u64 key;
+
+	if (prog->aux->sleepable && prog->type != BPF_PROG_TYPE_TRACING &&
+	    prog->type != BPF_PROG_TYPE_LSM) {
+		verbose(env, "Only fentry/fexit/fmod_ret and lsm programs can be sleepable\n");
+		return -EINVAL;
+	}
+
+	if (prog->type == BPF_PROG_TYPE_STRUCT_OPS)
+		return check_struct_ops_btf_id(env);
+
+	if (prog->type != BPF_PROG_TYPE_TRACING &&
+	    prog->type != BPF_PROG_TYPE_LSM &&
+	    prog->type != BPF_PROG_TYPE_EXT)
+		return 0;
+
+	ret = bpf_check_attach_target(&env->log, prog, tgt_prog, btf_id, &tgt_info);
+	if (ret)
+		return ret;
+
+	if (tgt_prog && prog->type == BPF_PROG_TYPE_EXT) {
+		/* to make freplace equivalent to their targets, they need to
+		 * inherit env->ops and expected_attach_type for the rest of the
+		 * verification
+		 */
+		env->ops = bpf_verifier_ops[tgt_prog->type];
+		prog->expected_attach_type = tgt_prog->expected_attach_type;
+	}
+
+	/* store info about the attachment target that will be used later */
+	prog->aux->attach_func_proto = tgt_info.tgt_type;
+	prog->aux->attach_func_name = tgt_info.tgt_name;
+
+	if (tgt_prog) {
+		prog->aux->saved_dst_prog_type = tgt_prog->type;
+		prog->aux->saved_dst_attach_type = tgt_prog->expected_attach_type;
+	}
+
+	if (prog->expected_attach_type == BPF_TRACE_RAW_TP) {
+		prog->aux->attach_btf_trace = true;
+		return 0;
+	} else if (prog->expected_attach_type == BPF_TRACE_ITER) {
+		if (!bpf_iter_prog_supported(prog))
+			return -EINVAL;
+		return 0;
+	}
+
+	if (prog->type == BPF_PROG_TYPE_LSM) {
+		ret = bpf_lsm_verify_prog(&env->log, prog);
+		if (ret < 0)
+			return ret;
+	}
+
+	key = bpf_trampoline_compute_key(tgt_prog, btf_id);
+	tr = bpf_trampoline_get(key, &tgt_info);
+	if (!tr)
+		return -ENOMEM;
+
+	prog->aux->dst_trampoline = tr;
+	return 0;
+}
+
+struct btf *bpf_get_btf_vmlinux(void)
+{
+	if (!btf_vmlinux && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
+		mutex_lock(&bpf_verifier_lock);
+		if (!btf_vmlinux)
+			btf_vmlinux = btf_parse_vmlinux();
+		mutex_unlock(&bpf_verifier_lock);
+	}
+	return btf_vmlinux;
+}
+
+int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
+	      union bpf_attr __user *uattr)
+{
+	u64 start_time = ktime_get_ns();
+	struct bpf_verifier_env *env;
+	struct bpf_verifier_log *log;
+	int i, len, ret = -EINVAL;
+	bool is_priv;
+
+	/* no program is valid */
+	if (ARRAY_SIZE(bpf_verifier_ops) == 0)
+		return -EINVAL;
+
+	/* 'struct bpf_verifier_env' can be global, but since it's not small,
+	 * allocate/free it every time bpf_check() is called
+	 */
+	env = kzalloc(sizeof(struct bpf_verifier_env), GFP_KERNEL);
+	if (!env)
+		return -ENOMEM;
+	log = &env->log;
+
+	len = (*prog)->len;
+	env->insn_aux_data =
+		vzalloc(array_size(sizeof(struct bpf_insn_aux_data), len));
+	ret = -ENOMEM;
+	if (!env->insn_aux_data)
+		goto err_free_env;
+	for (i = 0; i < len; i++)
+		env->insn_aux_data[i].orig_idx = i;
+	env->prog = *prog;
+	env->ops = bpf_verifier_ops[env->prog->type];
+	is_priv = bpf_capable();
+
+	bpf_get_btf_vmlinux();
+
+	/* grab the mutex to protect few globals used by verifier */
+	if (!is_priv)
+		mutex_lock(&bpf_verifier_lock);
+
+	if (attr->log_level || attr->log_buf || attr->log_size) {
+		/* user requested verbose verifier output
+		 * and supplied buffer to store the verification trace
+		 */
+		log->level = attr->log_level;
+		log->ubuf = (char __user *) (unsigned long) attr->log_buf;
+		log->len_total = attr->log_size;
+
+		/* log attributes have to be sane */
+		if (!bpf_verifier_log_attr_valid(log)) {
+			ret = -EINVAL;
+			goto err_unlock;
+		}
+	}
+
+	if (IS_ERR(btf_vmlinux)) {
+		/* Either gcc or pahole or kernel are broken. */
+		verbose(env, "in-kernel BTF is malformed\n");
+		ret = PTR_ERR(btf_vmlinux);
+		goto skip_full_check;
+	}
+
+	env->strict_alignment = !!(attr->prog_flags & BPF_F_STRICT_ALIGNMENT);
+	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS))
+		env->strict_alignment = true;
+	if (attr->prog_flags & BPF_F_ANY_ALIGNMENT)
+		env->strict_alignment = false;
+
+	env->allow_ptr_leaks = bpf_allow_ptr_leaks();
+	env->allow_uninit_stack = bpf_allow_uninit_stack();
+	env->allow_ptr_to_map_access = bpf_allow_ptr_to_map_access();
+	env->bypass_spec_v1 = bpf_bypass_spec_v1();
+	env->bypass_spec_v4 = bpf_bypass_spec_v4();
+	env->bpf_capable = bpf_capable();
+
+	if (is_priv)
+		env->test_state_freq = attr->prog_flags & BPF_F_TEST_STATE_FREQ;
+
+	env->explored_states = kvcalloc(state_htab_size(env),
+				       sizeof(struct bpf_verifier_state_list *),
+				       GFP_USER);
+	ret = -ENOMEM;
+	if (!env->explored_states)
+		goto skip_full_check;
+
+	ret = check_subprogs(env);
+	if (ret < 0)
+		goto skip_full_check;
+
+	ret = check_btf_info(env, attr, uattr);
+	if (ret < 0)
+		goto skip_full_check;
+
+	ret = check_attach_btf_id(env);
+	if (ret)
+		goto skip_full_check;
+
+	ret = resolve_pseudo_ldimm64(env);
+	if (ret < 0)
+		goto skip_full_check;
+
+	if (bpf_prog_is_dev_bound(env->prog->aux)) {
+		ret = bpf_prog_offload_verifier_prep(env->prog);
+		if (ret)
+			goto skip_full_check;
+	}
+
+	ret = check_cfg(env);
+	if (ret < 0)
+		goto skip_full_check;
+
+	ret = do_check_subprogs(env);
+	ret = ret ?: do_check_main(env);
+
+	if (ret == 0 && bpf_prog_is_dev_bound(env->prog->aux))
+		ret = bpf_prog_offload_finalize(env);
+
+skip_full_check:
+	kvfree(env->explored_states);
+
+	if (ret == 0)
+		ret = check_max_stack_depth(env);
+
+	/* instruction rewrites happen after this point */
+	if (is_priv) {
+		if (ret == 0)
+			opt_hard_wire_dead_code_branches(env);
+		if (ret == 0)
+			ret = opt_remove_dead_code(env);
+		if (ret == 0)
+			ret = opt_remove_nops(env);
+	} else {
+		if (ret == 0)
+			sanitize_dead_code(env);
+	}
+
+	if (ret == 0)
+		/* program is valid, convert *(u32*)(ctx + off) accesses */
+		ret = convert_ctx_accesses(env);
+
+	if (ret == 0)
+		ret = fixup_bpf_calls(env);
+
+	/* do 32-bit optimization after insn patching has done so those patched
+	 * insns could be handled correctly.
+	 */
+	if (ret == 0 && !bpf_prog_is_dev_bound(env->prog->aux)) {
+		ret = opt_subreg_zext_lo32_rnd_hi32(env, attr);
+		env->prog->aux->verifier_zext = bpf_jit_needs_zext() ? !ret
+								     : false;
+	}
+
+	if (ret == 0)
+		ret = fixup_call_args(env);
+
+	env->verification_time = ktime_get_ns() - start_time;
+	print_verification_stats(env);
+
+	if (log->level && bpf_verifier_log_full(log))
+		ret = -ENOSPC;
+	if (log->level && !log->ubuf) {
+		ret = -EFAULT;
+		goto err_release_maps;
+	}
+
+	if (ret == 0 && env->used_map_cnt) {
+		/* if program passed verifier, update used_maps in bpf_prog_info */
+		env->prog->aux->used_maps = kmalloc_array(env->used_map_cnt,
+							  sizeof(env->used_maps[0]),
+							  GFP_KERNEL);
+
+		if (!env->prog->aux->used_maps) {
+			ret = -ENOMEM;
+			goto err_release_maps;
+		}
+
+		memcpy(env->prog->aux->used_maps, env->used_maps,
+		       sizeof(env->used_maps[0]) * env->used_map_cnt);
+		env->prog->aux->used_map_cnt = env->used_map_cnt;
+
+		/* program is valid. Convert pseudo bpf_ld_imm64 into generic
+		 * bpf_ld_imm64 instructions
+		 */
+		convert_pseudo_ld_imm64(env);
+	}
+
+	if (ret == 0)
+		adjust_btf_func(env);
+
+err_release_maps:
+	if (!env->prog->aux->used_maps)
+		/* if we didn't copy map pointers into bpf_prog_info, release
+		 * them now. Otherwise free_used_maps() will release them.
+		 */
+		release_maps(env);
+
+	/* extension progs temporarily inherit the attach_type of their targets
+	   for verification purposes, so set it back to zero before returning
+	 */
+	if (env->prog->type == BPF_PROG_TYPE_EXT)
+		env->prog->expected_attach_type = 0;
+
+	*prog = env->prog;
+err_unlock:
+	if (!is_priv)
+		mutex_unlock(&bpf_verifier_lock);
+	vfree(env->insn_aux_data);
+err_free_env:
+	kfree(env);
+	return ret;
+}