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-rw-r--r--kernel/bpf/helpers.c2540
1 files changed, 2540 insertions, 0 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
new file mode 100644
index 000000000..607be04db
--- /dev/null
+++ b/kernel/bpf/helpers.c
@@ -0,0 +1,2540 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ */
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/bpf-cgroup.h>
+#include <linux/cgroup.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/poison.h>
+#include <linux/proc_ns.h>
+#include <linux/sched/task.h>
+#include <linux/security.h>
+#include <linux/btf_ids.h>
+#include <linux/bpf_mem_alloc.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() && !rcu_read_lock_bh_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() && !rcu_read_lock_bh_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() && !rcu_read_lock_bh_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_MAP_VALUE | MEM_UNINIT,
+};
+
+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_MAP_VALUE | MEM_UNINIT,
+};
+
+BPF_CALL_3(bpf_map_lookup_percpu_elem, struct bpf_map *, map, void *, key, u32, cpu)
+{
+ WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
+ return (unsigned long) map->ops->map_lookup_percpu_elem(map, key, cpu);
+}
+
+const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto = {
+ .func = bpf_map_lookup_percpu_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,
+ .arg3_type = ARG_ANYTHING,
+};
+
+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_ktime_get_coarse_ns)
+{
+ return ktime_get_coarse_ns();
+}
+
+const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto = {
+ .func = bpf_ktime_get_coarse_ns,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+};
+
+BPF_CALL_0(bpf_ktime_get_tai_ns)
+{
+ /* NMI safe access to clock tai */
+ return ktime_get_tai_fast_ns();
+}
+
+const struct bpf_func_proto bpf_ktime_get_tai_ns_proto = {
+ .func = bpf_ktime_get_tai_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;
+
+ /* Verifier guarantees that size > 0 */
+ strscpy_pad(buf, task->comm, size);
+ 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));
+ preempt_disable();
+ 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);
+ preempt_enable();
+}
+
+#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);
+
+static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __bpf_spin_lock(lock);
+ __this_cpu_write(irqsave_flags, flags);
+}
+
+notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
+{
+ __bpf_spin_lock_irqsave(lock);
+ 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,
+ .arg1_btf_id = BPF_PTR_POISON,
+};
+
+static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock)
+{
+ unsigned long flags;
+
+ flags = __this_cpu_read(irqsave_flags);
+ __bpf_spin_unlock(lock);
+ local_irq_restore(flags);
+}
+
+notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
+{
+ __bpf_spin_unlock_irqrestore(lock);
+ 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,
+ .arg1_btf_id = BPF_PTR_POISON,
+};
+
+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->record->spin_lock_off;
+ else
+ lock = dst + map->record->spin_lock_off;
+ preempt_disable();
+ __bpf_spin_lock_irqsave(lock);
+ copy_map_value(map, dst, src);
+ __bpf_spin_unlock_irqrestore(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;
+ u64 cgrp_id;
+
+ rcu_read_lock();
+ cgrp = task_dfl_cgroup(current);
+ cgrp_id = cgroup_id(cgrp);
+ rcu_read_unlock();
+
+ return cgrp_id;
+}
+
+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;
+ struct cgroup *ancestor;
+ u64 cgrp_id;
+
+ rcu_read_lock();
+ cgrp = task_dfl_cgroup(current);
+ ancestor = cgroup_ancestor(cgrp, ancestor_level);
+ cgrp_id = ancestor ? cgroup_id(ancestor) : 0;
+ rcu_read_unlock();
+
+ return cgrp_id;
+}
+
+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,
+};
+#endif /* CONFIG_CGROUPS */
+
+#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 | MEM_RDONLY,
+ .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 | MEM_RDONLY,
+ .arg2_type = ARG_CONST_SIZE,
+ .arg3_type = ARG_ANYTHING,
+ .arg4_type = ARG_PTR_TO_LONG,
+};
+
+BPF_CALL_3(bpf_strncmp, const char *, s1, u32, s1_sz, const char *, s2)
+{
+ return strncmp(s1, s2, s1_sz);
+}
+
+static const struct bpf_func_proto bpf_strncmp_proto = {
+ .func = bpf_strncmp,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
+ .arg2_type = ARG_CONST_SIZE,
+ .arg3_type = ARG_PTR_TO_CONST_STR,
+};
+
+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 | MEM_RDONLY,
+ .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,
+ .might_sleep = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_UNINIT_MEM,
+ .arg2_type = ARG_CONST_SIZE_OR_ZERO,
+ .arg3_type = ARG_ANYTHING,
+};
+
+BPF_CALL_5(bpf_copy_from_user_task, void *, dst, u32, size,
+ const void __user *, user_ptr, struct task_struct *, tsk, u64, flags)
+{
+ int ret;
+
+ /* flags is not used yet */
+ if (unlikely(flags))
+ return -EINVAL;
+
+ if (unlikely(!size))
+ return 0;
+
+ ret = access_process_vm(tsk, (unsigned long)user_ptr, dst, size, 0);
+ if (ret == size)
+ return 0;
+
+ memset(dst, 0, size);
+ /* Return -EFAULT for partial read */
+ return ret < 0 ? ret : -EFAULT;
+}
+
+const struct bpf_func_proto bpf_copy_from_user_task_proto = {
+ .func = bpf_copy_from_user_task,
+ .gpl_only = true,
+ .might_sleep = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_UNINIT_MEM,
+ .arg2_type = ARG_CONST_SIZE_OR_ZERO,
+ .arg3_type = ARG_ANYTHING,
+ .arg4_type = ARG_PTR_TO_BTF_ID,
+ .arg4_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
+ .arg5_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 | PTR_MAYBE_NULL | MEM_RDONLY,
+ .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 | MEM_RDONLY,
+ .arg1_type = ARG_PTR_TO_PERCPU_BTF_ID,
+};
+
+static int bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
+ size_t bufsz)
+{
+ void __user *user_ptr = (__force void __user *)unsafe_ptr;
+
+ buf[0] = 0;
+
+ switch (fmt_ptype) {
+ case 's':
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+ if ((unsigned long)unsafe_ptr < TASK_SIZE)
+ return strncpy_from_user_nofault(buf, user_ptr, bufsz);
+ fallthrough;
+#endif
+ case 'k':
+ return strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
+ case 'u':
+ return strncpy_from_user_nofault(buf, user_ptr, bufsz);
+ }
+
+ return -EINVAL;
+}
+
+/* Per-cpu temp buffers used by printf-like helpers to store the bprintf binary
+ * arguments representation.
+ */
+#define MAX_BPRINTF_BIN_ARGS 512
+
+/* Support executing three nested bprintf helper calls on a given CPU */
+#define MAX_BPRINTF_NEST_LEVEL 3
+struct bpf_bprintf_buffers {
+ char bin_args[MAX_BPRINTF_BIN_ARGS];
+ char buf[MAX_BPRINTF_BUF];
+};
+
+static DEFINE_PER_CPU(struct bpf_bprintf_buffers[MAX_BPRINTF_NEST_LEVEL], bpf_bprintf_bufs);
+static DEFINE_PER_CPU(int, bpf_bprintf_nest_level);
+
+static int try_get_buffers(struct bpf_bprintf_buffers **bufs)
+{
+ int nest_level;
+
+ preempt_disable();
+ nest_level = this_cpu_inc_return(bpf_bprintf_nest_level);
+ if (WARN_ON_ONCE(nest_level > MAX_BPRINTF_NEST_LEVEL)) {
+ this_cpu_dec(bpf_bprintf_nest_level);
+ preempt_enable();
+ return -EBUSY;
+ }
+ *bufs = this_cpu_ptr(&bpf_bprintf_bufs[nest_level - 1]);
+
+ return 0;
+}
+
+void bpf_bprintf_cleanup(struct bpf_bprintf_data *data)
+{
+ if (!data->bin_args && !data->buf)
+ return;
+ if (WARN_ON_ONCE(this_cpu_read(bpf_bprintf_nest_level) == 0))
+ return;
+ this_cpu_dec(bpf_bprintf_nest_level);
+ preempt_enable();
+}
+
+/*
+ * bpf_bprintf_prepare - Generic pass on format strings for bprintf-like helpers
+ *
+ * Returns a negative value if fmt is an invalid format string or 0 otherwise.
+ *
+ * This can be used in two ways:
+ * - Format string verification only: when data->get_bin_args is false
+ * - Arguments preparation: in addition to the above verification, it writes in
+ * data->bin_args a binary representation of arguments usable by bstr_printf
+ * where pointers from BPF have been sanitized.
+ *
+ * In argument preparation mode, if 0 is returned, safe temporary buffers are
+ * allocated and bpf_bprintf_cleanup should be called to free them after use.
+ */
+int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args,
+ u32 num_args, struct bpf_bprintf_data *data)
+{
+ bool get_buffers = (data->get_bin_args && num_args) || data->get_buf;
+ char *unsafe_ptr = NULL, *tmp_buf = NULL, *tmp_buf_end, *fmt_end;
+ struct bpf_bprintf_buffers *buffers = NULL;
+ size_t sizeof_cur_arg, sizeof_cur_ip;
+ int err, i, num_spec = 0;
+ u64 cur_arg;
+ char fmt_ptype, cur_ip[16], ip_spec[] = "%pXX";
+
+ fmt_end = strnchr(fmt, fmt_size, 0);
+ if (!fmt_end)
+ return -EINVAL;
+ fmt_size = fmt_end - fmt;
+
+ if (get_buffers && try_get_buffers(&buffers))
+ return -EBUSY;
+
+ if (data->get_bin_args) {
+ if (num_args)
+ tmp_buf = buffers->bin_args;
+ tmp_buf_end = tmp_buf + MAX_BPRINTF_BIN_ARGS;
+ data->bin_args = (u32 *)tmp_buf;
+ }
+
+ if (data->get_buf)
+ data->buf = buffers->buf;
+
+ for (i = 0; i < fmt_size; i++) {
+ if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (fmt[i] != '%')
+ continue;
+
+ if (fmt[i + 1] == '%') {
+ i++;
+ continue;
+ }
+
+ if (num_spec >= num_args) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ /* The string is zero-terminated so if fmt[i] != 0, we can
+ * always access fmt[i + 1], in the worst case it will be a 0
+ */
+ i++;
+
+ /* skip optional "[0 +-][num]" width formatting field */
+ while (fmt[i] == '0' || fmt[i] == '+' || fmt[i] == '-' ||
+ fmt[i] == ' ')
+ i++;
+ if (fmt[i] >= '1' && fmt[i] <= '9') {
+ i++;
+ while (fmt[i] >= '0' && fmt[i] <= '9')
+ i++;
+ }
+
+ if (fmt[i] == 'p') {
+ sizeof_cur_arg = sizeof(long);
+
+ if ((fmt[i + 1] == 'k' || fmt[i + 1] == 'u') &&
+ fmt[i + 2] == 's') {
+ fmt_ptype = fmt[i + 1];
+ i += 2;
+ goto fmt_str;
+ }
+
+ if (fmt[i + 1] == 0 || isspace(fmt[i + 1]) ||
+ ispunct(fmt[i + 1]) || fmt[i + 1] == 'K' ||
+ fmt[i + 1] == 'x' || fmt[i + 1] == 's' ||
+ fmt[i + 1] == 'S') {
+ /* just kernel pointers */
+ if (tmp_buf)
+ cur_arg = raw_args[num_spec];
+ i++;
+ goto nocopy_fmt;
+ }
+
+ if (fmt[i + 1] == 'B') {
+ if (tmp_buf) {
+ err = snprintf(tmp_buf,
+ (tmp_buf_end - tmp_buf),
+ "%pB",
+ (void *)(long)raw_args[num_spec]);
+ tmp_buf += (err + 1);
+ }
+
+ i++;
+ num_spec++;
+ continue;
+ }
+
+ /* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
+ if ((fmt[i + 1] != 'i' && fmt[i + 1] != 'I') ||
+ (fmt[i + 2] != '4' && fmt[i + 2] != '6')) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ i += 2;
+ if (!tmp_buf)
+ goto nocopy_fmt;
+
+ sizeof_cur_ip = (fmt[i] == '4') ? 4 : 16;
+ if (tmp_buf_end - tmp_buf < sizeof_cur_ip) {
+ err = -ENOSPC;
+ goto out;
+ }
+
+ unsafe_ptr = (char *)(long)raw_args[num_spec];
+ err = copy_from_kernel_nofault(cur_ip, unsafe_ptr,
+ sizeof_cur_ip);
+ if (err < 0)
+ memset(cur_ip, 0, sizeof_cur_ip);
+
+ /* hack: bstr_printf expects IP addresses to be
+ * pre-formatted as strings, ironically, the easiest way
+ * to do that is to call snprintf.
+ */
+ ip_spec[2] = fmt[i - 1];
+ ip_spec[3] = fmt[i];
+ err = snprintf(tmp_buf, tmp_buf_end - tmp_buf,
+ ip_spec, &cur_ip);
+
+ tmp_buf += err + 1;
+ num_spec++;
+
+ continue;
+ } else if (fmt[i] == 's') {
+ fmt_ptype = fmt[i];
+fmt_str:
+ if (fmt[i + 1] != 0 &&
+ !isspace(fmt[i + 1]) &&
+ !ispunct(fmt[i + 1])) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (!tmp_buf)
+ goto nocopy_fmt;
+
+ if (tmp_buf_end == tmp_buf) {
+ err = -ENOSPC;
+ goto out;
+ }
+
+ unsafe_ptr = (char *)(long)raw_args[num_spec];
+ err = bpf_trace_copy_string(tmp_buf, unsafe_ptr,
+ fmt_ptype,
+ tmp_buf_end - tmp_buf);
+ if (err < 0) {
+ tmp_buf[0] = '\0';
+ err = 1;
+ }
+
+ tmp_buf += err;
+ num_spec++;
+
+ continue;
+ } else if (fmt[i] == 'c') {
+ if (!tmp_buf)
+ goto nocopy_fmt;
+
+ if (tmp_buf_end == tmp_buf) {
+ err = -ENOSPC;
+ goto out;
+ }
+
+ *tmp_buf = raw_args[num_spec];
+ tmp_buf++;
+ num_spec++;
+
+ continue;
+ }
+
+ sizeof_cur_arg = sizeof(int);
+
+ if (fmt[i] == 'l') {
+ sizeof_cur_arg = sizeof(long);
+ i++;
+ }
+ if (fmt[i] == 'l') {
+ sizeof_cur_arg = sizeof(long long);
+ i++;
+ }
+
+ if (fmt[i] != 'i' && fmt[i] != 'd' && fmt[i] != 'u' &&
+ fmt[i] != 'x' && fmt[i] != 'X') {
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (tmp_buf)
+ cur_arg = raw_args[num_spec];
+nocopy_fmt:
+ if (tmp_buf) {
+ tmp_buf = PTR_ALIGN(tmp_buf, sizeof(u32));
+ if (tmp_buf_end - tmp_buf < sizeof_cur_arg) {
+ err = -ENOSPC;
+ goto out;
+ }
+
+ if (sizeof_cur_arg == 8) {
+ *(u32 *)tmp_buf = *(u32 *)&cur_arg;
+ *(u32 *)(tmp_buf + 4) = *((u32 *)&cur_arg + 1);
+ } else {
+ *(u32 *)tmp_buf = (u32)(long)cur_arg;
+ }
+ tmp_buf += sizeof_cur_arg;
+ }
+ num_spec++;
+ }
+
+ err = 0;
+out:
+ if (err)
+ bpf_bprintf_cleanup(data);
+ return err;
+}
+
+BPF_CALL_5(bpf_snprintf, char *, str, u32, str_size, char *, fmt,
+ const void *, args, u32, data_len)
+{
+ struct bpf_bprintf_data data = {
+ .get_bin_args = true,
+ };
+ int err, num_args;
+
+ if (data_len % 8 || data_len > MAX_BPRINTF_VARARGS * 8 ||
+ (data_len && !args))
+ return -EINVAL;
+ num_args = data_len / 8;
+
+ /* ARG_PTR_TO_CONST_STR guarantees that fmt is zero-terminated so we
+ * can safely give an unbounded size.
+ */
+ err = bpf_bprintf_prepare(fmt, UINT_MAX, args, num_args, &data);
+ if (err < 0)
+ return err;
+
+ err = bstr_printf(str, str_size, fmt, data.bin_args);
+
+ bpf_bprintf_cleanup(&data);
+
+ return err + 1;
+}
+
+const struct bpf_func_proto bpf_snprintf_proto = {
+ .func = bpf_snprintf,
+ .gpl_only = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_MEM_OR_NULL,
+ .arg2_type = ARG_CONST_SIZE_OR_ZERO,
+ .arg3_type = ARG_PTR_TO_CONST_STR,
+ .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
+ .arg5_type = ARG_CONST_SIZE_OR_ZERO,
+};
+
+/* BPF map elements can contain 'struct bpf_timer'.
+ * Such map owns all of its BPF timers.
+ * 'struct bpf_timer' is allocated as part of map element allocation
+ * and it's zero initialized.
+ * That space is used to keep 'struct bpf_timer_kern'.
+ * bpf_timer_init() allocates 'struct bpf_hrtimer', inits hrtimer, and
+ * remembers 'struct bpf_map *' pointer it's part of.
+ * bpf_timer_set_callback() increments prog refcnt and assign bpf callback_fn.
+ * bpf_timer_start() arms the timer.
+ * If user space reference to a map goes to zero at this point
+ * ops->map_release_uref callback is responsible for cancelling the timers,
+ * freeing their memory, and decrementing prog's refcnts.
+ * bpf_timer_cancel() cancels the timer and decrements prog's refcnt.
+ * Inner maps can contain bpf timers as well. ops->map_release_uref is
+ * freeing the timers when inner map is replaced or deleted by user space.
+ */
+struct bpf_hrtimer {
+ struct hrtimer timer;
+ struct bpf_map *map;
+ struct bpf_prog *prog;
+ void __rcu *callback_fn;
+ void *value;
+};
+
+/* the actual struct hidden inside uapi struct bpf_timer */
+struct bpf_timer_kern {
+ struct bpf_hrtimer *timer;
+ /* bpf_spin_lock is used here instead of spinlock_t to make
+ * sure that it always fits into space reserved by struct bpf_timer
+ * regardless of LOCKDEP and spinlock debug flags.
+ */
+ struct bpf_spin_lock lock;
+} __attribute__((aligned(8)));
+
+static DEFINE_PER_CPU(struct bpf_hrtimer *, hrtimer_running);
+
+static enum hrtimer_restart bpf_timer_cb(struct hrtimer *hrtimer)
+{
+ struct bpf_hrtimer *t = container_of(hrtimer, struct bpf_hrtimer, timer);
+ struct bpf_map *map = t->map;
+ void *value = t->value;
+ bpf_callback_t callback_fn;
+ void *key;
+ u32 idx;
+
+ BTF_TYPE_EMIT(struct bpf_timer);
+ callback_fn = rcu_dereference_check(t->callback_fn, rcu_read_lock_bh_held());
+ if (!callback_fn)
+ goto out;
+
+ /* bpf_timer_cb() runs in hrtimer_run_softirq. It doesn't migrate and
+ * cannot be preempted by another bpf_timer_cb() on the same cpu.
+ * Remember the timer this callback is servicing to prevent
+ * deadlock if callback_fn() calls bpf_timer_cancel() or
+ * bpf_map_delete_elem() on the same timer.
+ */
+ this_cpu_write(hrtimer_running, t);
+ if (map->map_type == BPF_MAP_TYPE_ARRAY) {
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+
+ /* compute the key */
+ idx = ((char *)value - array->value) / array->elem_size;
+ key = &idx;
+ } else { /* hash or lru */
+ key = value - round_up(map->key_size, 8);
+ }
+
+ callback_fn((u64)(long)map, (u64)(long)key, (u64)(long)value, 0, 0);
+ /* The verifier checked that return value is zero. */
+
+ this_cpu_write(hrtimer_running, NULL);
+out:
+ return HRTIMER_NORESTART;
+}
+
+BPF_CALL_3(bpf_timer_init, struct bpf_timer_kern *, timer, struct bpf_map *, map,
+ u64, flags)
+{
+ clockid_t clockid = flags & (MAX_CLOCKS - 1);
+ struct bpf_hrtimer *t;
+ int ret = 0;
+
+ BUILD_BUG_ON(MAX_CLOCKS != 16);
+ BUILD_BUG_ON(sizeof(struct bpf_timer_kern) > sizeof(struct bpf_timer));
+ BUILD_BUG_ON(__alignof__(struct bpf_timer_kern) != __alignof__(struct bpf_timer));
+
+ if (in_nmi())
+ return -EOPNOTSUPP;
+
+ if (flags >= MAX_CLOCKS ||
+ /* similar to timerfd except _ALARM variants are not supported */
+ (clockid != CLOCK_MONOTONIC &&
+ clockid != CLOCK_REALTIME &&
+ clockid != CLOCK_BOOTTIME))
+ return -EINVAL;
+ __bpf_spin_lock_irqsave(&timer->lock);
+ t = timer->timer;
+ if (t) {
+ ret = -EBUSY;
+ goto out;
+ }
+ /* allocate hrtimer via map_kmalloc to use memcg accounting */
+ t = bpf_map_kmalloc_node(map, sizeof(*t), GFP_ATOMIC, map->numa_node);
+ if (!t) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ t->value = (void *)timer - map->record->timer_off;
+ t->map = map;
+ t->prog = NULL;
+ rcu_assign_pointer(t->callback_fn, NULL);
+ hrtimer_init(&t->timer, clockid, HRTIMER_MODE_REL_SOFT);
+ t->timer.function = bpf_timer_cb;
+ WRITE_ONCE(timer->timer, t);
+ /* Guarantee the order between timer->timer and map->usercnt. So
+ * when there are concurrent uref release and bpf timer init, either
+ * bpf_timer_cancel_and_free() called by uref release reads a no-NULL
+ * timer or atomic64_read() below returns a zero usercnt.
+ */
+ smp_mb();
+ if (!atomic64_read(&map->usercnt)) {
+ /* maps with timers must be either held by user space
+ * or pinned in bpffs.
+ */
+ WRITE_ONCE(timer->timer, NULL);
+ kfree(t);
+ ret = -EPERM;
+ }
+out:
+ __bpf_spin_unlock_irqrestore(&timer->lock);
+ return ret;
+}
+
+static const struct bpf_func_proto bpf_timer_init_proto = {
+ .func = bpf_timer_init,
+ .gpl_only = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_TIMER,
+ .arg2_type = ARG_CONST_MAP_PTR,
+ .arg3_type = ARG_ANYTHING,
+};
+
+BPF_CALL_3(bpf_timer_set_callback, struct bpf_timer_kern *, timer, void *, callback_fn,
+ struct bpf_prog_aux *, aux)
+{
+ struct bpf_prog *prev, *prog = aux->prog;
+ struct bpf_hrtimer *t;
+ int ret = 0;
+
+ if (in_nmi())
+ return -EOPNOTSUPP;
+ __bpf_spin_lock_irqsave(&timer->lock);
+ t = timer->timer;
+ if (!t) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (!atomic64_read(&t->map->usercnt)) {
+ /* maps with timers must be either held by user space
+ * or pinned in bpffs. Otherwise timer might still be
+ * running even when bpf prog is detached and user space
+ * is gone, since map_release_uref won't ever be called.
+ */
+ ret = -EPERM;
+ goto out;
+ }
+ prev = t->prog;
+ if (prev != prog) {
+ /* Bump prog refcnt once. Every bpf_timer_set_callback()
+ * can pick different callback_fn-s within the same prog.
+ */
+ prog = bpf_prog_inc_not_zero(prog);
+ if (IS_ERR(prog)) {
+ ret = PTR_ERR(prog);
+ goto out;
+ }
+ if (prev)
+ /* Drop prev prog refcnt when swapping with new prog */
+ bpf_prog_put(prev);
+ t->prog = prog;
+ }
+ rcu_assign_pointer(t->callback_fn, callback_fn);
+out:
+ __bpf_spin_unlock_irqrestore(&timer->lock);
+ return ret;
+}
+
+static const struct bpf_func_proto bpf_timer_set_callback_proto = {
+ .func = bpf_timer_set_callback,
+ .gpl_only = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_TIMER,
+ .arg2_type = ARG_PTR_TO_FUNC,
+};
+
+BPF_CALL_3(bpf_timer_start, struct bpf_timer_kern *, timer, u64, nsecs, u64, flags)
+{
+ struct bpf_hrtimer *t;
+ int ret = 0;
+ enum hrtimer_mode mode;
+
+ if (in_nmi())
+ return -EOPNOTSUPP;
+ if (flags > BPF_F_TIMER_ABS)
+ return -EINVAL;
+ __bpf_spin_lock_irqsave(&timer->lock);
+ t = timer->timer;
+ if (!t || !t->prog) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (flags & BPF_F_TIMER_ABS)
+ mode = HRTIMER_MODE_ABS_SOFT;
+ else
+ mode = HRTIMER_MODE_REL_SOFT;
+
+ hrtimer_start(&t->timer, ns_to_ktime(nsecs), mode);
+out:
+ __bpf_spin_unlock_irqrestore(&timer->lock);
+ return ret;
+}
+
+static const struct bpf_func_proto bpf_timer_start_proto = {
+ .func = bpf_timer_start,
+ .gpl_only = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_TIMER,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_ANYTHING,
+};
+
+static void drop_prog_refcnt(struct bpf_hrtimer *t)
+{
+ struct bpf_prog *prog = t->prog;
+
+ if (prog) {
+ bpf_prog_put(prog);
+ t->prog = NULL;
+ rcu_assign_pointer(t->callback_fn, NULL);
+ }
+}
+
+BPF_CALL_1(bpf_timer_cancel, struct bpf_timer_kern *, timer)
+{
+ struct bpf_hrtimer *t;
+ int ret = 0;
+
+ if (in_nmi())
+ return -EOPNOTSUPP;
+ __bpf_spin_lock_irqsave(&timer->lock);
+ t = timer->timer;
+ if (!t) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (this_cpu_read(hrtimer_running) == t) {
+ /* If bpf callback_fn is trying to bpf_timer_cancel()
+ * its own timer the hrtimer_cancel() will deadlock
+ * since it waits for callback_fn to finish
+ */
+ ret = -EDEADLK;
+ goto out;
+ }
+ drop_prog_refcnt(t);
+out:
+ __bpf_spin_unlock_irqrestore(&timer->lock);
+ /* Cancel the timer and wait for associated callback to finish
+ * if it was running.
+ */
+ ret = ret ?: hrtimer_cancel(&t->timer);
+ return ret;
+}
+
+static const struct bpf_func_proto bpf_timer_cancel_proto = {
+ .func = bpf_timer_cancel,
+ .gpl_only = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_TIMER,
+};
+
+/* This function is called by map_delete/update_elem for individual element and
+ * by ops->map_release_uref when the user space reference to a map reaches zero.
+ */
+void bpf_timer_cancel_and_free(void *val)
+{
+ struct bpf_timer_kern *timer = val;
+ struct bpf_hrtimer *t;
+
+ /* Performance optimization: read timer->timer without lock first. */
+ if (!READ_ONCE(timer->timer))
+ return;
+
+ __bpf_spin_lock_irqsave(&timer->lock);
+ /* re-read it under lock */
+ t = timer->timer;
+ if (!t)
+ goto out;
+ drop_prog_refcnt(t);
+ /* The subsequent bpf_timer_start/cancel() helpers won't be able to use
+ * this timer, since it won't be initialized.
+ */
+ WRITE_ONCE(timer->timer, NULL);
+out:
+ __bpf_spin_unlock_irqrestore(&timer->lock);
+ if (!t)
+ return;
+ /* Cancel the timer and wait for callback to complete if it was running.
+ * If hrtimer_cancel() can be safely called it's safe to call kfree(t)
+ * right after for both preallocated and non-preallocated maps.
+ * The timer->timer = NULL was already done and no code path can
+ * see address 't' anymore.
+ *
+ * Check that bpf_map_delete/update_elem() wasn't called from timer
+ * callback_fn. In such case don't call hrtimer_cancel() (since it will
+ * deadlock) and don't call hrtimer_try_to_cancel() (since it will just
+ * return -1). Though callback_fn is still running on this cpu it's
+ * safe to do kfree(t) because bpf_timer_cb() read everything it needed
+ * from 't'. The bpf subprog callback_fn won't be able to access 't',
+ * since timer->timer = NULL was already done. The timer will be
+ * effectively cancelled because bpf_timer_cb() will return
+ * HRTIMER_NORESTART.
+ */
+ if (this_cpu_read(hrtimer_running) != t)
+ hrtimer_cancel(&t->timer);
+ kfree(t);
+}
+
+BPF_CALL_2(bpf_kptr_xchg, void *, map_value, void *, ptr)
+{
+ unsigned long *kptr = map_value;
+
+ return xchg(kptr, (unsigned long)ptr);
+}
+
+/* Unlike other PTR_TO_BTF_ID helpers the btf_id in bpf_kptr_xchg()
+ * helper is determined dynamically by the verifier. Use BPF_PTR_POISON to
+ * denote type that verifier will determine.
+ */
+static const struct bpf_func_proto bpf_kptr_xchg_proto = {
+ .func = bpf_kptr_xchg,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_BTF_ID_OR_NULL,
+ .ret_btf_id = BPF_PTR_POISON,
+ .arg1_type = ARG_PTR_TO_KPTR,
+ .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL | OBJ_RELEASE,
+ .arg2_btf_id = BPF_PTR_POISON,
+};
+
+/* Since the upper 8 bits of dynptr->size is reserved, the
+ * maximum supported size is 2^24 - 1.
+ */
+#define DYNPTR_MAX_SIZE ((1UL << 24) - 1)
+#define DYNPTR_TYPE_SHIFT 28
+#define DYNPTR_SIZE_MASK 0xFFFFFF
+#define DYNPTR_RDONLY_BIT BIT(31)
+
+static bool __bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr)
+{
+ return ptr->size & DYNPTR_RDONLY_BIT;
+}
+
+void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr)
+{
+ ptr->size |= DYNPTR_RDONLY_BIT;
+}
+
+static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_type type)
+{
+ ptr->size |= type << DYNPTR_TYPE_SHIFT;
+}
+
+static enum bpf_dynptr_type bpf_dynptr_get_type(const struct bpf_dynptr_kern *ptr)
+{
+ return (ptr->size & ~(DYNPTR_RDONLY_BIT)) >> DYNPTR_TYPE_SHIFT;
+}
+
+u32 __bpf_dynptr_size(const struct bpf_dynptr_kern *ptr)
+{
+ return ptr->size & DYNPTR_SIZE_MASK;
+}
+
+static void bpf_dynptr_set_size(struct bpf_dynptr_kern *ptr, u32 new_size)
+{
+ u32 metadata = ptr->size & ~DYNPTR_SIZE_MASK;
+
+ ptr->size = new_size | metadata;
+}
+
+int bpf_dynptr_check_size(u32 size)
+{
+ return size > DYNPTR_MAX_SIZE ? -E2BIG : 0;
+}
+
+void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data,
+ enum bpf_dynptr_type type, u32 offset, u32 size)
+{
+ ptr->data = data;
+ ptr->offset = offset;
+ ptr->size = size;
+ bpf_dynptr_set_type(ptr, type);
+}
+
+void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr)
+{
+ memset(ptr, 0, sizeof(*ptr));
+}
+
+static int bpf_dynptr_check_off_len(const struct bpf_dynptr_kern *ptr, u32 offset, u32 len)
+{
+ u32 size = __bpf_dynptr_size(ptr);
+
+ if (len > size || offset > size - len)
+ return -E2BIG;
+
+ return 0;
+}
+
+BPF_CALL_4(bpf_dynptr_from_mem, void *, data, u32, size, u64, flags, struct bpf_dynptr_kern *, ptr)
+{
+ int err;
+
+ BTF_TYPE_EMIT(struct bpf_dynptr);
+
+ err = bpf_dynptr_check_size(size);
+ if (err)
+ goto error;
+
+ /* flags is currently unsupported */
+ if (flags) {
+ err = -EINVAL;
+ goto error;
+ }
+
+ bpf_dynptr_init(ptr, data, BPF_DYNPTR_TYPE_LOCAL, 0, size);
+
+ return 0;
+
+error:
+ bpf_dynptr_set_null(ptr);
+ return err;
+}
+
+static const struct bpf_func_proto bpf_dynptr_from_mem_proto = {
+ .func = bpf_dynptr_from_mem,
+ .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,
+ .arg4_type = ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL | MEM_UNINIT,
+};
+
+BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, const struct bpf_dynptr_kern *, src,
+ u32, offset, u64, flags)
+{
+ enum bpf_dynptr_type type;
+ int err;
+
+ if (!src->data || flags)
+ return -EINVAL;
+
+ err = bpf_dynptr_check_off_len(src, offset, len);
+ if (err)
+ return err;
+
+ type = bpf_dynptr_get_type(src);
+
+ switch (type) {
+ case BPF_DYNPTR_TYPE_LOCAL:
+ case BPF_DYNPTR_TYPE_RINGBUF:
+ /* Source and destination may possibly overlap, hence use memmove to
+ * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
+ * pointing to overlapping PTR_TO_MAP_VALUE regions.
+ */
+ memmove(dst, src->data + src->offset + offset, len);
+ return 0;
+ case BPF_DYNPTR_TYPE_SKB:
+ return __bpf_skb_load_bytes(src->data, src->offset + offset, dst, len);
+ case BPF_DYNPTR_TYPE_XDP:
+ return __bpf_xdp_load_bytes(src->data, src->offset + offset, dst, len);
+ default:
+ WARN_ONCE(true, "bpf_dynptr_read: unknown dynptr type %d\n", type);
+ return -EFAULT;
+ }
+}
+
+static const struct bpf_func_proto bpf_dynptr_read_proto = {
+ .func = bpf_dynptr_read,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_UNINIT_MEM,
+ .arg2_type = ARG_CONST_SIZE_OR_ZERO,
+ .arg3_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
+ .arg4_type = ARG_ANYTHING,
+ .arg5_type = ARG_ANYTHING,
+};
+
+BPF_CALL_5(bpf_dynptr_write, const struct bpf_dynptr_kern *, dst, u32, offset, void *, src,
+ u32, len, u64, flags)
+{
+ enum bpf_dynptr_type type;
+ int err;
+
+ if (!dst->data || __bpf_dynptr_is_rdonly(dst))
+ return -EINVAL;
+
+ err = bpf_dynptr_check_off_len(dst, offset, len);
+ if (err)
+ return err;
+
+ type = bpf_dynptr_get_type(dst);
+
+ switch (type) {
+ case BPF_DYNPTR_TYPE_LOCAL:
+ case BPF_DYNPTR_TYPE_RINGBUF:
+ if (flags)
+ return -EINVAL;
+ /* Source and destination may possibly overlap, hence use memmove to
+ * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
+ * pointing to overlapping PTR_TO_MAP_VALUE regions.
+ */
+ memmove(dst->data + dst->offset + offset, src, len);
+ return 0;
+ case BPF_DYNPTR_TYPE_SKB:
+ return __bpf_skb_store_bytes(dst->data, dst->offset + offset, src, len,
+ flags);
+ case BPF_DYNPTR_TYPE_XDP:
+ if (flags)
+ return -EINVAL;
+ return __bpf_xdp_store_bytes(dst->data, dst->offset + offset, src, len);
+ default:
+ WARN_ONCE(true, "bpf_dynptr_write: unknown dynptr type %d\n", type);
+ return -EFAULT;
+ }
+}
+
+static const struct bpf_func_proto bpf_dynptr_write_proto = {
+ .func = bpf_dynptr_write,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
+ .arg4_type = ARG_CONST_SIZE_OR_ZERO,
+ .arg5_type = ARG_ANYTHING,
+};
+
+BPF_CALL_3(bpf_dynptr_data, const struct bpf_dynptr_kern *, ptr, u32, offset, u32, len)
+{
+ enum bpf_dynptr_type type;
+ int err;
+
+ if (!ptr->data)
+ return 0;
+
+ err = bpf_dynptr_check_off_len(ptr, offset, len);
+ if (err)
+ return 0;
+
+ if (__bpf_dynptr_is_rdonly(ptr))
+ return 0;
+
+ type = bpf_dynptr_get_type(ptr);
+
+ switch (type) {
+ case BPF_DYNPTR_TYPE_LOCAL:
+ case BPF_DYNPTR_TYPE_RINGBUF:
+ return (unsigned long)(ptr->data + ptr->offset + offset);
+ case BPF_DYNPTR_TYPE_SKB:
+ case BPF_DYNPTR_TYPE_XDP:
+ /* skb and xdp dynptrs should use bpf_dynptr_slice / bpf_dynptr_slice_rdwr */
+ return 0;
+ default:
+ WARN_ONCE(true, "bpf_dynptr_data: unknown dynptr type %d\n", type);
+ return 0;
+ }
+}
+
+static const struct bpf_func_proto bpf_dynptr_data_proto = {
+ .func = bpf_dynptr_data,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_DYNPTR_MEM_OR_NULL,
+ .arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_CONST_ALLOC_SIZE_OR_ZERO,
+};
+
+const struct bpf_func_proto bpf_get_current_task_proto __weak;
+const struct bpf_func_proto bpf_get_current_task_btf_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_task_pt_regs_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_map_lookup_percpu_elem:
+ return &bpf_map_lookup_percpu_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_ktime_get_tai_ns:
+ return &bpf_ktime_get_tai_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;
+ case BPF_FUNC_strncmp:
+ return &bpf_strncmp_proto;
+ case BPF_FUNC_strtol:
+ return &bpf_strtol_proto;
+ case BPF_FUNC_strtoul:
+ return &bpf_strtoul_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;
+ case BPF_FUNC_timer_init:
+ return &bpf_timer_init_proto;
+ case BPF_FUNC_timer_set_callback:
+ return &bpf_timer_set_callback_proto;
+ case BPF_FUNC_timer_start:
+ return &bpf_timer_start_proto;
+ case BPF_FUNC_timer_cancel:
+ return &bpf_timer_cancel_proto;
+ case BPF_FUNC_kptr_xchg:
+ return &bpf_kptr_xchg_proto;
+ case BPF_FUNC_for_each_map_elem:
+ return &bpf_for_each_map_elem_proto;
+ case BPF_FUNC_loop:
+ return &bpf_loop_proto;
+ case BPF_FUNC_user_ringbuf_drain:
+ return &bpf_user_ringbuf_drain_proto;
+ case BPF_FUNC_ringbuf_reserve_dynptr:
+ return &bpf_ringbuf_reserve_dynptr_proto;
+ case BPF_FUNC_ringbuf_submit_dynptr:
+ return &bpf_ringbuf_submit_dynptr_proto;
+ case BPF_FUNC_ringbuf_discard_dynptr:
+ return &bpf_ringbuf_discard_dynptr_proto;
+ case BPF_FUNC_dynptr_from_mem:
+ return &bpf_dynptr_from_mem_proto;
+ case BPF_FUNC_dynptr_read:
+ return &bpf_dynptr_read_proto;
+ case BPF_FUNC_dynptr_write:
+ return &bpf_dynptr_write_proto;
+ case BPF_FUNC_dynptr_data:
+ return &bpf_dynptr_data_proto;
+#ifdef CONFIG_CGROUPS
+ case BPF_FUNC_cgrp_storage_get:
+ return &bpf_cgrp_storage_get_proto;
+ case BPF_FUNC_cgrp_storage_delete:
+ return &bpf_cgrp_storage_delete_proto;
+ case BPF_FUNC_get_current_cgroup_id:
+ return &bpf_get_current_cgroup_id_proto;
+ case BPF_FUNC_get_current_ancestor_cgroup_id:
+ return &bpf_get_current_ancestor_cgroup_id_proto;
+#endif
+ 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_get_current_task_btf:
+ return &bpf_get_current_task_btf_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_KERNEL) < 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_KERNEL) < 0 ?
+ NULL : &bpf_probe_read_kernel_str_proto;
+ case BPF_FUNC_snprintf_btf:
+ return &bpf_snprintf_btf_proto;
+ case BPF_FUNC_snprintf:
+ return &bpf_snprintf_proto;
+ case BPF_FUNC_task_pt_regs:
+ return &bpf_task_pt_regs_proto;
+ case BPF_FUNC_trace_vprintk:
+ return bpf_get_trace_vprintk_proto();
+ default:
+ return NULL;
+ }
+}
+
+void __bpf_obj_drop_impl(void *p, const struct btf_record *rec);
+
+void bpf_list_head_free(const struct btf_field *field, void *list_head,
+ struct bpf_spin_lock *spin_lock)
+{
+ struct list_head *head = list_head, *orig_head = list_head;
+
+ BUILD_BUG_ON(sizeof(struct list_head) > sizeof(struct bpf_list_head));
+ BUILD_BUG_ON(__alignof__(struct list_head) > __alignof__(struct bpf_list_head));
+
+ /* Do the actual list draining outside the lock to not hold the lock for
+ * too long, and also prevent deadlocks if tracing programs end up
+ * executing on entry/exit of functions called inside the critical
+ * section, and end up doing map ops that call bpf_list_head_free for
+ * the same map value again.
+ */
+ __bpf_spin_lock_irqsave(spin_lock);
+ if (!head->next || list_empty(head))
+ goto unlock;
+ head = head->next;
+unlock:
+ INIT_LIST_HEAD(orig_head);
+ __bpf_spin_unlock_irqrestore(spin_lock);
+
+ while (head != orig_head) {
+ void *obj = head;
+
+ obj -= field->graph_root.node_offset;
+ head = head->next;
+ /* The contained type can also have resources, including a
+ * bpf_list_head which needs to be freed.
+ */
+ migrate_disable();
+ __bpf_obj_drop_impl(obj, field->graph_root.value_rec);
+ migrate_enable();
+ }
+}
+
+/* Like rbtree_postorder_for_each_entry_safe, but 'pos' and 'n' are
+ * 'rb_node *', so field name of rb_node within containing struct is not
+ * needed.
+ *
+ * Since bpf_rb_tree's node type has a corresponding struct btf_field with
+ * graph_root.node_offset, it's not necessary to know field name
+ * or type of node struct
+ */
+#define bpf_rbtree_postorder_for_each_entry_safe(pos, n, root) \
+ for (pos = rb_first_postorder(root); \
+ pos && ({ n = rb_next_postorder(pos); 1; }); \
+ pos = n)
+
+void bpf_rb_root_free(const struct btf_field *field, void *rb_root,
+ struct bpf_spin_lock *spin_lock)
+{
+ struct rb_root_cached orig_root, *root = rb_root;
+ struct rb_node *pos, *n;
+ void *obj;
+
+ BUILD_BUG_ON(sizeof(struct rb_root_cached) > sizeof(struct bpf_rb_root));
+ BUILD_BUG_ON(__alignof__(struct rb_root_cached) > __alignof__(struct bpf_rb_root));
+
+ __bpf_spin_lock_irqsave(spin_lock);
+ orig_root = *root;
+ *root = RB_ROOT_CACHED;
+ __bpf_spin_unlock_irqrestore(spin_lock);
+
+ bpf_rbtree_postorder_for_each_entry_safe(pos, n, &orig_root.rb_root) {
+ obj = pos;
+ obj -= field->graph_root.node_offset;
+
+
+ migrate_disable();
+ __bpf_obj_drop_impl(obj, field->graph_root.value_rec);
+ migrate_enable();
+ }
+}
+
+__diag_push();
+__diag_ignore_all("-Wmissing-prototypes",
+ "Global functions as their definitions will be in vmlinux BTF");
+
+__bpf_kfunc void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign)
+{
+ struct btf_struct_meta *meta = meta__ign;
+ u64 size = local_type_id__k;
+ void *p;
+
+ p = bpf_mem_alloc(&bpf_global_ma, size);
+ if (!p)
+ return NULL;
+ if (meta)
+ bpf_obj_init(meta->record, p);
+ return p;
+}
+
+/* Must be called under migrate_disable(), as required by bpf_mem_free */
+void __bpf_obj_drop_impl(void *p, const struct btf_record *rec)
+{
+ if (rec && rec->refcount_off >= 0 &&
+ !refcount_dec_and_test((refcount_t *)(p + rec->refcount_off))) {
+ /* Object is refcounted and refcount_dec didn't result in 0
+ * refcount. Return without freeing the object
+ */
+ return;
+ }
+
+ if (rec)
+ bpf_obj_free_fields(rec, p);
+
+ if (rec && rec->refcount_off >= 0)
+ bpf_mem_free_rcu(&bpf_global_ma, p);
+ else
+ bpf_mem_free(&bpf_global_ma, p);
+}
+
+__bpf_kfunc void bpf_obj_drop_impl(void *p__alloc, void *meta__ign)
+{
+ struct btf_struct_meta *meta = meta__ign;
+ void *p = p__alloc;
+
+ __bpf_obj_drop_impl(p, meta ? meta->record : NULL);
+}
+
+__bpf_kfunc void *bpf_refcount_acquire_impl(void *p__refcounted_kptr, void *meta__ign)
+{
+ struct btf_struct_meta *meta = meta__ign;
+ struct bpf_refcount *ref;
+
+ /* Could just cast directly to refcount_t *, but need some code using
+ * bpf_refcount type so that it is emitted in vmlinux BTF
+ */
+ ref = (struct bpf_refcount *)(p__refcounted_kptr + meta->record->refcount_off);
+ if (!refcount_inc_not_zero((refcount_t *)ref))
+ return NULL;
+
+ /* Verifier strips KF_RET_NULL if input is owned ref, see is_kfunc_ret_null
+ * in verifier.c
+ */
+ return (void *)p__refcounted_kptr;
+}
+
+static int __bpf_list_add(struct bpf_list_node_kern *node,
+ struct bpf_list_head *head,
+ bool tail, struct btf_record *rec, u64 off)
+{
+ struct list_head *n = &node->list_head, *h = (void *)head;
+
+ /* If list_head was 0-initialized by map, bpf_obj_init_field wasn't
+ * called on its fields, so init here
+ */
+ if (unlikely(!h->next))
+ INIT_LIST_HEAD(h);
+
+ /* node->owner != NULL implies !list_empty(n), no need to separately
+ * check the latter
+ */
+ if (cmpxchg(&node->owner, NULL, BPF_PTR_POISON)) {
+ /* Only called from BPF prog, no need to migrate_disable */
+ __bpf_obj_drop_impl((void *)n - off, rec);
+ return -EINVAL;
+ }
+
+ tail ? list_add_tail(n, h) : list_add(n, h);
+ WRITE_ONCE(node->owner, head);
+
+ return 0;
+}
+
+__bpf_kfunc int bpf_list_push_front_impl(struct bpf_list_head *head,
+ struct bpf_list_node *node,
+ void *meta__ign, u64 off)
+{
+ struct bpf_list_node_kern *n = (void *)node;
+ struct btf_struct_meta *meta = meta__ign;
+
+ return __bpf_list_add(n, head, false, meta ? meta->record : NULL, off);
+}
+
+__bpf_kfunc int bpf_list_push_back_impl(struct bpf_list_head *head,
+ struct bpf_list_node *node,
+ void *meta__ign, u64 off)
+{
+ struct bpf_list_node_kern *n = (void *)node;
+ struct btf_struct_meta *meta = meta__ign;
+
+ return __bpf_list_add(n, head, true, meta ? meta->record : NULL, off);
+}
+
+static struct bpf_list_node *__bpf_list_del(struct bpf_list_head *head, bool tail)
+{
+ struct list_head *n, *h = (void *)head;
+ struct bpf_list_node_kern *node;
+
+ /* If list_head was 0-initialized by map, bpf_obj_init_field wasn't
+ * called on its fields, so init here
+ */
+ if (unlikely(!h->next))
+ INIT_LIST_HEAD(h);
+ if (list_empty(h))
+ return NULL;
+
+ n = tail ? h->prev : h->next;
+ node = container_of(n, struct bpf_list_node_kern, list_head);
+ if (WARN_ON_ONCE(READ_ONCE(node->owner) != head))
+ return NULL;
+
+ list_del_init(n);
+ WRITE_ONCE(node->owner, NULL);
+ return (struct bpf_list_node *)n;
+}
+
+__bpf_kfunc struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head)
+{
+ return __bpf_list_del(head, false);
+}
+
+__bpf_kfunc struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head)
+{
+ return __bpf_list_del(head, true);
+}
+
+__bpf_kfunc struct bpf_rb_node *bpf_rbtree_remove(struct bpf_rb_root *root,
+ struct bpf_rb_node *node)
+{
+ struct bpf_rb_node_kern *node_internal = (struct bpf_rb_node_kern *)node;
+ struct rb_root_cached *r = (struct rb_root_cached *)root;
+ struct rb_node *n = &node_internal->rb_node;
+
+ /* node_internal->owner != root implies either RB_EMPTY_NODE(n) or
+ * n is owned by some other tree. No need to check RB_EMPTY_NODE(n)
+ */
+ if (READ_ONCE(node_internal->owner) != root)
+ return NULL;
+
+ rb_erase_cached(n, r);
+ RB_CLEAR_NODE(n);
+ WRITE_ONCE(node_internal->owner, NULL);
+ return (struct bpf_rb_node *)n;
+}
+
+/* Need to copy rbtree_add_cached's logic here because our 'less' is a BPF
+ * program
+ */
+static int __bpf_rbtree_add(struct bpf_rb_root *root,
+ struct bpf_rb_node_kern *node,
+ void *less, struct btf_record *rec, u64 off)
+{
+ struct rb_node **link = &((struct rb_root_cached *)root)->rb_root.rb_node;
+ struct rb_node *parent = NULL, *n = &node->rb_node;
+ bpf_callback_t cb = (bpf_callback_t)less;
+ bool leftmost = true;
+
+ /* node->owner != NULL implies !RB_EMPTY_NODE(n), no need to separately
+ * check the latter
+ */
+ if (cmpxchg(&node->owner, NULL, BPF_PTR_POISON)) {
+ /* Only called from BPF prog, no need to migrate_disable */
+ __bpf_obj_drop_impl((void *)n - off, rec);
+ return -EINVAL;
+ }
+
+ while (*link) {
+ parent = *link;
+ if (cb((uintptr_t)node, (uintptr_t)parent, 0, 0, 0)) {
+ link = &parent->rb_left;
+ } else {
+ link = &parent->rb_right;
+ leftmost = false;
+ }
+ }
+
+ rb_link_node(n, parent, link);
+ rb_insert_color_cached(n, (struct rb_root_cached *)root, leftmost);
+ WRITE_ONCE(node->owner, root);
+ return 0;
+}
+
+__bpf_kfunc int bpf_rbtree_add_impl(struct bpf_rb_root *root, struct bpf_rb_node *node,
+ bool (less)(struct bpf_rb_node *a, const struct bpf_rb_node *b),
+ void *meta__ign, u64 off)
+{
+ struct btf_struct_meta *meta = meta__ign;
+ struct bpf_rb_node_kern *n = (void *)node;
+
+ return __bpf_rbtree_add(root, n, (void *)less, meta ? meta->record : NULL, off);
+}
+
+__bpf_kfunc struct bpf_rb_node *bpf_rbtree_first(struct bpf_rb_root *root)
+{
+ struct rb_root_cached *r = (struct rb_root_cached *)root;
+
+ return (struct bpf_rb_node *)rb_first_cached(r);
+}
+
+/**
+ * bpf_task_acquire - Acquire a reference to a task. A task acquired by this
+ * kfunc which is not stored in a map as a kptr, must be released by calling
+ * bpf_task_release().
+ * @p: The task on which a reference is being acquired.
+ */
+__bpf_kfunc struct task_struct *bpf_task_acquire(struct task_struct *p)
+{
+ if (refcount_inc_not_zero(&p->rcu_users))
+ return p;
+ return NULL;
+}
+
+/**
+ * bpf_task_release - Release the reference acquired on a task.
+ * @p: The task on which a reference is being released.
+ */
+__bpf_kfunc void bpf_task_release(struct task_struct *p)
+{
+ put_task_struct_rcu_user(p);
+}
+
+#ifdef CONFIG_CGROUPS
+/**
+ * bpf_cgroup_acquire - Acquire a reference to a cgroup. A cgroup acquired by
+ * this kfunc which is not stored in a map as a kptr, must be released by
+ * calling bpf_cgroup_release().
+ * @cgrp: The cgroup on which a reference is being acquired.
+ */
+__bpf_kfunc struct cgroup *bpf_cgroup_acquire(struct cgroup *cgrp)
+{
+ return cgroup_tryget(cgrp) ? cgrp : NULL;
+}
+
+/**
+ * bpf_cgroup_release - Release the reference acquired on a cgroup.
+ * If this kfunc is invoked in an RCU read region, the cgroup is guaranteed to
+ * not be freed until the current grace period has ended, even if its refcount
+ * drops to 0.
+ * @cgrp: The cgroup on which a reference is being released.
+ */
+__bpf_kfunc void bpf_cgroup_release(struct cgroup *cgrp)
+{
+ cgroup_put(cgrp);
+}
+
+/**
+ * bpf_cgroup_ancestor - Perform a lookup on an entry in a cgroup's ancestor
+ * array. A cgroup returned by this kfunc which is not subsequently stored in a
+ * map, must be released by calling bpf_cgroup_release().
+ * @cgrp: The cgroup for which we're performing a lookup.
+ * @level: The level of ancestor to look up.
+ */
+__bpf_kfunc struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level)
+{
+ struct cgroup *ancestor;
+
+ if (level > cgrp->level || level < 0)
+ return NULL;
+
+ /* cgrp's refcnt could be 0 here, but ancestors can still be accessed */
+ ancestor = cgrp->ancestors[level];
+ if (!cgroup_tryget(ancestor))
+ return NULL;
+ return ancestor;
+}
+
+/**
+ * bpf_cgroup_from_id - Find a cgroup from its ID. A cgroup returned by this
+ * kfunc which is not subsequently stored in a map, must be released by calling
+ * bpf_cgroup_release().
+ * @cgid: cgroup id.
+ */
+__bpf_kfunc struct cgroup *bpf_cgroup_from_id(u64 cgid)
+{
+ struct cgroup *cgrp;
+
+ cgrp = cgroup_get_from_id(cgid);
+ if (IS_ERR(cgrp))
+ return NULL;
+ return cgrp;
+}
+
+/**
+ * bpf_task_under_cgroup - wrap task_under_cgroup_hierarchy() as a kfunc, test
+ * task's membership of cgroup ancestry.
+ * @task: the task to be tested
+ * @ancestor: possible ancestor of @task's cgroup
+ *
+ * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
+ * It follows all the same rules as cgroup_is_descendant, and only applies
+ * to the default hierarchy.
+ */
+__bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task,
+ struct cgroup *ancestor)
+{
+ long ret;
+
+ rcu_read_lock();
+ ret = task_under_cgroup_hierarchy(task, ancestor);
+ rcu_read_unlock();
+ return ret;
+}
+#endif /* CONFIG_CGROUPS */
+
+/**
+ * bpf_task_from_pid - Find a struct task_struct from its pid by looking it up
+ * in the root pid namespace idr. If a task is returned, it must either be
+ * stored in a map, or released with bpf_task_release().
+ * @pid: The pid of the task being looked up.
+ */
+__bpf_kfunc struct task_struct *bpf_task_from_pid(s32 pid)
+{
+ struct task_struct *p;
+
+ rcu_read_lock();
+ p = find_task_by_pid_ns(pid, &init_pid_ns);
+ if (p)
+ p = bpf_task_acquire(p);
+ rcu_read_unlock();
+
+ return p;
+}
+
+/**
+ * bpf_dynptr_slice() - Obtain a read-only pointer to the dynptr data.
+ * @ptr: The dynptr whose data slice to retrieve
+ * @offset: Offset into the dynptr
+ * @buffer__opt: User-provided buffer to copy contents into. May be NULL
+ * @buffer__szk: Size (in bytes) of the buffer if present. This is the
+ * length of the requested slice. This must be a constant.
+ *
+ * For non-skb and non-xdp type dynptrs, there is no difference between
+ * bpf_dynptr_slice and bpf_dynptr_data.
+ *
+ * If buffer__opt is NULL, the call will fail if buffer_opt was needed.
+ *
+ * If the intention is to write to the data slice, please use
+ * bpf_dynptr_slice_rdwr.
+ *
+ * The user must check that the returned pointer is not null before using it.
+ *
+ * Please note that in the case of skb and xdp dynptrs, bpf_dynptr_slice
+ * does not change the underlying packet data pointers, so a call to
+ * bpf_dynptr_slice will not invalidate any ctx->data/data_end pointers in
+ * the bpf program.
+ *
+ * Return: NULL if the call failed (eg invalid dynptr), pointer to a read-only
+ * data slice (can be either direct pointer to the data or a pointer to the user
+ * provided buffer, with its contents containing the data, if unable to obtain
+ * direct pointer)
+ */
+__bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr_kern *ptr, u32 offset,
+ void *buffer__opt, u32 buffer__szk)
+{
+ enum bpf_dynptr_type type;
+ u32 len = buffer__szk;
+ int err;
+
+ if (!ptr->data)
+ return NULL;
+
+ err = bpf_dynptr_check_off_len(ptr, offset, len);
+ if (err)
+ return NULL;
+
+ type = bpf_dynptr_get_type(ptr);
+
+ switch (type) {
+ case BPF_DYNPTR_TYPE_LOCAL:
+ case BPF_DYNPTR_TYPE_RINGBUF:
+ return ptr->data + ptr->offset + offset;
+ case BPF_DYNPTR_TYPE_SKB:
+ if (buffer__opt)
+ return skb_header_pointer(ptr->data, ptr->offset + offset, len, buffer__opt);
+ else
+ return skb_pointer_if_linear(ptr->data, ptr->offset + offset, len);
+ case BPF_DYNPTR_TYPE_XDP:
+ {
+ void *xdp_ptr = bpf_xdp_pointer(ptr->data, ptr->offset + offset, len);
+ if (!IS_ERR_OR_NULL(xdp_ptr))
+ return xdp_ptr;
+
+ if (!buffer__opt)
+ return NULL;
+ bpf_xdp_copy_buf(ptr->data, ptr->offset + offset, buffer__opt, len, false);
+ return buffer__opt;
+ }
+ default:
+ WARN_ONCE(true, "unknown dynptr type %d\n", type);
+ return NULL;
+ }
+}
+
+/**
+ * bpf_dynptr_slice_rdwr() - Obtain a writable pointer to the dynptr data.
+ * @ptr: The dynptr whose data slice to retrieve
+ * @offset: Offset into the dynptr
+ * @buffer__opt: User-provided buffer to copy contents into. May be NULL
+ * @buffer__szk: Size (in bytes) of the buffer if present. This is the
+ * length of the requested slice. This must be a constant.
+ *
+ * For non-skb and non-xdp type dynptrs, there is no difference between
+ * bpf_dynptr_slice and bpf_dynptr_data.
+ *
+ * If buffer__opt is NULL, the call will fail if buffer_opt was needed.
+ *
+ * The returned pointer is writable and may point to either directly the dynptr
+ * data at the requested offset or to the buffer if unable to obtain a direct
+ * data pointer to (example: the requested slice is to the paged area of an skb
+ * packet). In the case where the returned pointer is to the buffer, the user
+ * is responsible for persisting writes through calling bpf_dynptr_write(). This
+ * usually looks something like this pattern:
+ *
+ * struct eth_hdr *eth = bpf_dynptr_slice_rdwr(&dynptr, 0, buffer, sizeof(buffer));
+ * if (!eth)
+ * return TC_ACT_SHOT;
+ *
+ * // mutate eth header //
+ *
+ * if (eth == buffer)
+ * bpf_dynptr_write(&ptr, 0, buffer, sizeof(buffer), 0);
+ *
+ * Please note that, as in the example above, the user must check that the
+ * returned pointer is not null before using it.
+ *
+ * Please also note that in the case of skb and xdp dynptrs, bpf_dynptr_slice_rdwr
+ * does not change the underlying packet data pointers, so a call to
+ * bpf_dynptr_slice_rdwr will not invalidate any ctx->data/data_end pointers in
+ * the bpf program.
+ *
+ * Return: NULL if the call failed (eg invalid dynptr), pointer to a
+ * data slice (can be either direct pointer to the data or a pointer to the user
+ * provided buffer, with its contents containing the data, if unable to obtain
+ * direct pointer)
+ */
+__bpf_kfunc void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr_kern *ptr, u32 offset,
+ void *buffer__opt, u32 buffer__szk)
+{
+ if (!ptr->data || __bpf_dynptr_is_rdonly(ptr))
+ return NULL;
+
+ /* bpf_dynptr_slice_rdwr is the same logic as bpf_dynptr_slice.
+ *
+ * For skb-type dynptrs, it is safe to write into the returned pointer
+ * if the bpf program allows skb data writes. There are two possiblities
+ * that may occur when calling bpf_dynptr_slice_rdwr:
+ *
+ * 1) The requested slice is in the head of the skb. In this case, the
+ * returned pointer is directly to skb data, and if the skb is cloned, the
+ * verifier will have uncloned it (see bpf_unclone_prologue()) already.
+ * The pointer can be directly written into.
+ *
+ * 2) Some portion of the requested slice is in the paged buffer area.
+ * In this case, the requested data will be copied out into the buffer
+ * and the returned pointer will be a pointer to the buffer. The skb
+ * will not be pulled. To persist the write, the user will need to call
+ * bpf_dynptr_write(), which will pull the skb and commit the write.
+ *
+ * Similarly for xdp programs, if the requested slice is not across xdp
+ * fragments, then a direct pointer will be returned, otherwise the data
+ * will be copied out into the buffer and the user will need to call
+ * bpf_dynptr_write() to commit changes.
+ */
+ return bpf_dynptr_slice(ptr, offset, buffer__opt, buffer__szk);
+}
+
+__bpf_kfunc int bpf_dynptr_adjust(struct bpf_dynptr_kern *ptr, u32 start, u32 end)
+{
+ u32 size;
+
+ if (!ptr->data || start > end)
+ return -EINVAL;
+
+ size = __bpf_dynptr_size(ptr);
+
+ if (start > size || end > size)
+ return -ERANGE;
+
+ ptr->offset += start;
+ bpf_dynptr_set_size(ptr, end - start);
+
+ return 0;
+}
+
+__bpf_kfunc bool bpf_dynptr_is_null(struct bpf_dynptr_kern *ptr)
+{
+ return !ptr->data;
+}
+
+__bpf_kfunc bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr)
+{
+ if (!ptr->data)
+ return false;
+
+ return __bpf_dynptr_is_rdonly(ptr);
+}
+
+__bpf_kfunc __u32 bpf_dynptr_size(const struct bpf_dynptr_kern *ptr)
+{
+ if (!ptr->data)
+ return -EINVAL;
+
+ return __bpf_dynptr_size(ptr);
+}
+
+__bpf_kfunc int bpf_dynptr_clone(struct bpf_dynptr_kern *ptr,
+ struct bpf_dynptr_kern *clone__uninit)
+{
+ if (!ptr->data) {
+ bpf_dynptr_set_null(clone__uninit);
+ return -EINVAL;
+ }
+
+ *clone__uninit = *ptr;
+
+ return 0;
+}
+
+__bpf_kfunc void *bpf_cast_to_kern_ctx(void *obj)
+{
+ return obj;
+}
+
+__bpf_kfunc void *bpf_rdonly_cast(void *obj__ign, u32 btf_id__k)
+{
+ return obj__ign;
+}
+
+__bpf_kfunc void bpf_rcu_read_lock(void)
+{
+ rcu_read_lock();
+}
+
+__bpf_kfunc void bpf_rcu_read_unlock(void)
+{
+ rcu_read_unlock();
+}
+
+__diag_pop();
+
+BTF_SET8_START(generic_btf_ids)
+#ifdef CONFIG_KEXEC_CORE
+BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE)
+#endif
+BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_refcount_acquire_impl, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_list_push_front_impl)
+BTF_ID_FLAGS(func, bpf_list_push_back_impl)
+BTF_ID_FLAGS(func, bpf_list_pop_front, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_list_pop_back, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_task_release, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_rbtree_remove, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_rbtree_add_impl)
+BTF_ID_FLAGS(func, bpf_rbtree_first, KF_RET_NULL)
+
+#ifdef CONFIG_CGROUPS
+BTF_ID_FLAGS(func, bpf_cgroup_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU)
+#endif
+BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
+BTF_SET8_END(generic_btf_ids)
+
+static const struct btf_kfunc_id_set generic_kfunc_set = {
+ .owner = THIS_MODULE,
+ .set = &generic_btf_ids,
+};
+
+
+BTF_ID_LIST(generic_dtor_ids)
+BTF_ID(struct, task_struct)
+BTF_ID(func, bpf_task_release)
+#ifdef CONFIG_CGROUPS
+BTF_ID(struct, cgroup)
+BTF_ID(func, bpf_cgroup_release)
+#endif
+
+BTF_SET8_START(common_btf_ids)
+BTF_ID_FLAGS(func, bpf_cast_to_kern_ctx)
+BTF_ID_FLAGS(func, bpf_rdonly_cast)
+BTF_ID_FLAGS(func, bpf_rcu_read_lock)
+BTF_ID_FLAGS(func, bpf_rcu_read_unlock)
+BTF_ID_FLAGS(func, bpf_dynptr_slice, KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_dynptr_slice_rdwr, KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_iter_num_new, KF_ITER_NEW)
+BTF_ID_FLAGS(func, bpf_iter_num_next, KF_ITER_NEXT | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_iter_num_destroy, KF_ITER_DESTROY)
+BTF_ID_FLAGS(func, bpf_dynptr_adjust)
+BTF_ID_FLAGS(func, bpf_dynptr_is_null)
+BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly)
+BTF_ID_FLAGS(func, bpf_dynptr_size)
+BTF_ID_FLAGS(func, bpf_dynptr_clone)
+BTF_SET8_END(common_btf_ids)
+
+static const struct btf_kfunc_id_set common_kfunc_set = {
+ .owner = THIS_MODULE,
+ .set = &common_btf_ids,
+};
+
+static int __init kfunc_init(void)
+{
+ int ret;
+ const struct btf_id_dtor_kfunc generic_dtors[] = {
+ {
+ .btf_id = generic_dtor_ids[0],
+ .kfunc_btf_id = generic_dtor_ids[1]
+ },
+#ifdef CONFIG_CGROUPS
+ {
+ .btf_id = generic_dtor_ids[2],
+ .kfunc_btf_id = generic_dtor_ids[3]
+ },
+#endif
+ };
+
+ ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set);
+ ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &generic_kfunc_set);
+ ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);
+ ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,
+ ARRAY_SIZE(generic_dtors),
+ THIS_MODULE);
+ return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &common_kfunc_set);
+}
+
+late_initcall(kfunc_init);