summaryrefslogtreecommitdiffstats
path: root/kernel/bpf/map_in_map.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /kernel/bpf/map_in_map.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'kernel/bpf/map_in_map.c')
-rw-r--r--kernel/bpf/map_in_map.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c
new file mode 100644
index 000000000..141f33320
--- /dev/null
+++ b/kernel/bpf/map_in_map.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Facebook
+ */
+#include <linux/slab.h>
+#include <linux/bpf.h>
+#include <linux/btf.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;
+ inner_map_meta->timer_off = inner_map->timer_off;
+ inner_map_meta->kptr_off_tab = bpf_map_copy_kptr_off_tab(inner_map);
+ if (inner_map->btf) {
+ btf_get(inner_map->btf);
+ inner_map_meta->btf = inner_map->btf;
+ }
+
+ /* Misc members not needed in bpf_map_meta_equal() check. */
+ inner_map_meta->ops = inner_map->ops;
+ if (inner_map->ops == &array_map_ops) {
+ struct bpf_array *inner_array_meta =
+ container_of(inner_map_meta, struct bpf_array, map);
+ struct bpf_array *inner_array = container_of(inner_map, struct bpf_array, map);
+
+ inner_array_meta->index_mask = inner_array->index_mask;
+ inner_array_meta->elem_size = inner_array->elem_size;
+ inner_map_meta->bypass_spec_v1 = inner_map->bypass_spec_v1;
+ }
+
+ fdput(f);
+ return inner_map_meta;
+}
+
+void bpf_map_meta_free(struct bpf_map *map_meta)
+{
+ bpf_map_free_kptr_off_tab(map_meta);
+ btf_put(map_meta->btf);
+ 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->timer_off == meta1->timer_off &&
+ meta0->map_flags == meta1->map_flags &&
+ bpf_map_equal_kptr_off_tab(meta0, meta1);
+}
+
+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(struct bpf_map *map, void *ptr, bool need_defer)
+{
+ struct bpf_map *inner_map = ptr;
+
+ /* The inner map may still be used by both non-sleepable and sleepable
+ * bpf program, so free it after one RCU grace period and one tasks
+ * trace RCU grace period.
+ */
+ if (need_defer)
+ WRITE_ONCE(inner_map->free_after_mult_rcu_gp, true);
+ bpf_map_put(inner_map);
+}
+
+u32 bpf_map_fd_sys_lookup_elem(void *ptr)
+{
+ return ((struct bpf_map *)ptr)->id;
+}