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1/* Copyright (c) 2017 Facebook
2 *
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.
6 */
7#include <linux/slab.h>
8#include <linux/bpf.h>
9
10#include "map_in_map.h"
11
12struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
13{
14 struct bpf_map *inner_map, *inner_map_meta;
15 struct fd f;
16
17 f = fdget(inner_map_ufd);
18 inner_map = __bpf_map_get(f);
19 if (IS_ERR(inner_map))
20 return inner_map;
21
22 /* prog_array->owner_prog_type and owner_jited
23 * is a runtime binding. Doing static check alone
24 * in the verifier is not enough.
25 */
26 if (inner_map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
27 fdput(f);
28 return ERR_PTR(-ENOTSUPP);
29 }
30
31 /* Does not support >1 level map-in-map */
32 if (inner_map->inner_map_meta) {
33 fdput(f);
34 return ERR_PTR(-EINVAL);
35 }
36
37 inner_map_meta = kzalloc(sizeof(*inner_map_meta), GFP_USER);
38 if (!inner_map_meta) {
39 fdput(f);
40 return ERR_PTR(-ENOMEM);
41 }
42
43 inner_map_meta->map_type = inner_map->map_type;
44 inner_map_meta->key_size = inner_map->key_size;
45 inner_map_meta->value_size = inner_map->value_size;
46 inner_map_meta->map_flags = inner_map->map_flags;
47 inner_map_meta->ops = inner_map->ops;
48 inner_map_meta->max_entries = inner_map->max_entries;
49
50 fdput(f);
51 return inner_map_meta;
52}
53
54void bpf_map_meta_free(struct bpf_map *map_meta)
55{
56 kfree(map_meta);
57}
58
59bool bpf_map_meta_equal(const struct bpf_map *meta0,
60 const struct bpf_map *meta1)
61{
62 /* No need to compare ops because it is covered by map_type */
63 return meta0->map_type == meta1->map_type &&
64 meta0->key_size == meta1->key_size &&
65 meta0->value_size == meta1->value_size &&
66 meta0->map_flags == meta1->map_flags &&
67 meta0->max_entries == meta1->max_entries;
68}
69
70void *bpf_map_fd_get_ptr(struct bpf_map *map,
71 struct file *map_file /* not used */,
72 int ufd)
73{
74 struct bpf_map *inner_map;
75 struct fd f;
76
77 f = fdget(ufd);
78 inner_map = __bpf_map_get(f);
79 if (IS_ERR(inner_map))
80 return inner_map;
81
82 if (bpf_map_meta_equal(map->inner_map_meta, inner_map))
83 inner_map = bpf_map_inc(inner_map, false);
84 else
85 inner_map = ERR_PTR(-EINVAL);
86
87 fdput(f);
88 return inner_map;
89}
90
91void bpf_map_fd_put_ptr(void *ptr)
92{
93 /* ptr->ops->map_free() has to go through one
94 * rcu grace period by itself.
95 */
96 bpf_map_put(ptr);
97}
98
99u32 bpf_map_fd_sys_lookup_elem(void *ptr)
100{
101 return ((struct bpf_map *)ptr)->id;
102}
1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (c) 2017 Facebook
3 */
4#include <linux/slab.h>
5#include <linux/bpf.h>
6
7#include "map_in_map.h"
8
9struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
10{
11 struct bpf_map *inner_map, *inner_map_meta;
12 u32 inner_map_meta_size;
13 struct fd f;
14
15 f = fdget(inner_map_ufd);
16 inner_map = __bpf_map_get(f);
17 if (IS_ERR(inner_map))
18 return inner_map;
19
20 /* Does not support >1 level map-in-map */
21 if (inner_map->inner_map_meta) {
22 fdput(f);
23 return ERR_PTR(-EINVAL);
24 }
25
26 if (!inner_map->ops->map_meta_equal) {
27 fdput(f);
28 return ERR_PTR(-ENOTSUPP);
29 }
30
31 if (map_value_has_spin_lock(inner_map)) {
32 fdput(f);
33 return ERR_PTR(-ENOTSUPP);
34 }
35
36 inner_map_meta_size = sizeof(*inner_map_meta);
37 /* In some cases verifier needs to access beyond just base map. */
38 if (inner_map->ops == &array_map_ops)
39 inner_map_meta_size = sizeof(struct bpf_array);
40
41 inner_map_meta = kzalloc(inner_map_meta_size, GFP_USER);
42 if (!inner_map_meta) {
43 fdput(f);
44 return ERR_PTR(-ENOMEM);
45 }
46
47 inner_map_meta->map_type = inner_map->map_type;
48 inner_map_meta->key_size = inner_map->key_size;
49 inner_map_meta->value_size = inner_map->value_size;
50 inner_map_meta->map_flags = inner_map->map_flags;
51 inner_map_meta->max_entries = inner_map->max_entries;
52 inner_map_meta->spin_lock_off = inner_map->spin_lock_off;
53
54 /* Misc members not needed in bpf_map_meta_equal() check. */
55 inner_map_meta->ops = inner_map->ops;
56 if (inner_map->ops == &array_map_ops) {
57 inner_map_meta->bypass_spec_v1 = inner_map->bypass_spec_v1;
58 container_of(inner_map_meta, struct bpf_array, map)->index_mask =
59 container_of(inner_map, struct bpf_array, map)->index_mask;
60 }
61
62 fdput(f);
63 return inner_map_meta;
64}
65
66void bpf_map_meta_free(struct bpf_map *map_meta)
67{
68 kfree(map_meta);
69}
70
71bool bpf_map_meta_equal(const struct bpf_map *meta0,
72 const struct bpf_map *meta1)
73{
74 /* No need to compare ops because it is covered by map_type */
75 return meta0->map_type == meta1->map_type &&
76 meta0->key_size == meta1->key_size &&
77 meta0->value_size == meta1->value_size &&
78 meta0->map_flags == meta1->map_flags;
79}
80
81void *bpf_map_fd_get_ptr(struct bpf_map *map,
82 struct file *map_file /* not used */,
83 int ufd)
84{
85 struct bpf_map *inner_map, *inner_map_meta;
86 struct fd f;
87
88 f = fdget(ufd);
89 inner_map = __bpf_map_get(f);
90 if (IS_ERR(inner_map))
91 return inner_map;
92
93 inner_map_meta = map->inner_map_meta;
94 if (inner_map_meta->ops->map_meta_equal(inner_map_meta, inner_map))
95 bpf_map_inc(inner_map);
96 else
97 inner_map = ERR_PTR(-EINVAL);
98
99 fdput(f);
100 return inner_map;
101}
102
103void bpf_map_fd_put_ptr(void *ptr)
104{
105 /* ptr->ops->map_free() has to go through one
106 * rcu grace period by itself.
107 */
108 bpf_map_put(ptr);
109}
110
111u32 bpf_map_fd_sys_lookup_elem(void *ptr)
112{
113 return ((struct bpf_map *)ptr)->id;
114}