1 /* Copyright (c) 2017 Facebook
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
7 #include <linux/slab.h>
10 #include "map_in_map.h"
12 struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
14 struct bpf_map *inner_map, *inner_map_meta;
15 u32 inner_map_meta_size;
18 f = fdget(inner_map_ufd);
19 inner_map = __bpf_map_get(f);
20 if (IS_ERR(inner_map))
23 /* prog_array->owner_prog_type and owner_jited
24 * is a runtime binding. Doing static check alone
25 * in the verifier is not enough.
27 if (inner_map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||
28 inner_map->map_type == BPF_MAP_TYPE_CGROUP_STORAGE ||
29 inner_map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
31 return ERR_PTR(-ENOTSUPP);
34 /* Does not support >1 level map-in-map */
35 if (inner_map->inner_map_meta) {
37 return ERR_PTR(-EINVAL);
40 if (map_value_has_spin_lock(inner_map)) {
42 return ERR_PTR(-ENOTSUPP);
45 inner_map_meta_size = sizeof(*inner_map_meta);
46 /* In some cases verifier needs to access beyond just base map. */
47 if (inner_map->ops == &array_map_ops)
48 inner_map_meta_size = sizeof(struct bpf_array);
50 inner_map_meta = kzalloc(inner_map_meta_size, GFP_USER);
51 if (!inner_map_meta) {
53 return ERR_PTR(-ENOMEM);
56 inner_map_meta->map_type = inner_map->map_type;
57 inner_map_meta->key_size = inner_map->key_size;
58 inner_map_meta->value_size = inner_map->value_size;
59 inner_map_meta->map_flags = inner_map->map_flags;
60 inner_map_meta->max_entries = inner_map->max_entries;
61 inner_map_meta->spin_lock_off = inner_map->spin_lock_off;
63 /* Misc members not needed in bpf_map_meta_equal() check. */
64 inner_map_meta->ops = inner_map->ops;
65 if (inner_map->ops == &array_map_ops) {
66 inner_map_meta->unpriv_array = inner_map->unpriv_array;
67 container_of(inner_map_meta, struct bpf_array, map)->index_mask =
68 container_of(inner_map, struct bpf_array, map)->index_mask;
72 return inner_map_meta;
75 void bpf_map_meta_free(struct bpf_map *map_meta)
80 bool bpf_map_meta_equal(const struct bpf_map *meta0,
81 const struct bpf_map *meta1)
83 /* No need to compare ops because it is covered by map_type */
84 return meta0->map_type == meta1->map_type &&
85 meta0->key_size == meta1->key_size &&
86 meta0->value_size == meta1->value_size &&
87 meta0->map_flags == meta1->map_flags &&
88 meta0->max_entries == meta1->max_entries;
91 void *bpf_map_fd_get_ptr(struct bpf_map *map,
92 struct file *map_file /* not used */,
95 struct bpf_map *inner_map;
99 inner_map = __bpf_map_get(f);
100 if (IS_ERR(inner_map))
103 if (bpf_map_meta_equal(map->inner_map_meta, inner_map))
104 inner_map = bpf_map_inc(inner_map, false);
106 inner_map = ERR_PTR(-EINVAL);
112 void bpf_map_fd_put_ptr(void *ptr)
114 /* ptr->ops->map_free() has to go through one
115 * rcu grace period by itself.
120 u32 bpf_map_fd_sys_lookup_elem(void *ptr)
122 return ((struct bpf_map *)ptr)->id;