1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2 /* Copyright (c) 2019 Facebook */
3
4 #ifndef __RELO_CORE_H
5 #define __RELO_CORE_H
6
7 #include <linux/bpf.h>
8
9 struct bpf_core_cand {
10 const struct btf *btf;
11 __u32 id;
12 };
13
14 /* dynamically sized list of type IDs and its associated struct btf */
15 struct bpf_core_cand_list {
16 struct bpf_core_cand *cands;
17 int len;
18 };
19
20 #define BPF_CORE_SPEC_MAX_LEN 64
21
22 /* represents BPF CO-RE field or array element accessor */
23 struct bpf_core_accessor {
24 __u32 type_id; /* struct/union type or array element type */
25 __u32 idx; /* field index or array index */
26 const char *name; /* field name or NULL for array accessor */
27 };
28
29 struct bpf_core_spec {
30 const struct btf *btf;
31 /* high-level spec: named fields and array indices only */
32 struct bpf_core_accessor spec[BPF_CORE_SPEC_MAX_LEN];
33 /* original unresolved (no skip_mods_or_typedefs) root type ID */
34 __u32 root_type_id;
35 /* CO-RE relocation kind */
36 enum bpf_core_relo_kind relo_kind;
37 /* high-level spec length */
38 int len;
39 /* raw, low-level spec: 1-to-1 with accessor spec string */
40 int raw_spec[BPF_CORE_SPEC_MAX_LEN];
41 /* raw spec length */
42 int raw_len;
43 /* field bit offset represented by spec */
44 __u32 bit_offset;
45 };
46
47 struct bpf_core_relo_res {
48 /* expected value in the instruction, unless validate == false */
49 __u64 orig_val;
50 /* new value that needs to be patched up to */
51 __u64 new_val;
52 /* relocation unsuccessful, poison instruction, but don't fail load */
53 bool poison;
54 /* some relocations can't be validated against orig_val */
55 bool validate;
56 /* for field byte offset relocations or the forms:
57 * *(T *)(rX + <off>) = rY
58 * rX = *(T *)(rY + <off>),
59 * we remember original and resolved field size to adjust direct
60 * memory loads of pointers and integers; this is necessary for 32-bit
61 * host kernel architectures, but also allows to automatically
62 * relocate fields that were resized from, e.g., u32 to u64, etc.
63 */
64 bool fail_memsz_adjust;
65 __u32 orig_sz;
66 __u32 orig_type_id;
67 __u32 new_sz;
68 __u32 new_type_id;
69 };
70
71 int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
72 const struct btf *targ_btf, __u32 targ_id, int level);
73 int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
74 const struct btf *targ_btf, __u32 targ_id);
75 int __bpf_core_types_match(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf,
76 __u32 targ_id, bool behind_ptr, int level);
77 int bpf_core_types_match(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf,
78 __u32 targ_id);
79
80 size_t bpf_core_essential_name_len(const char *name);
81
82 int bpf_core_calc_relo_insn(const char *prog_name,
83 const struct bpf_core_relo *relo, int relo_idx,
84 const struct btf *local_btf,
85 struct bpf_core_cand_list *cands,
86 struct bpf_core_spec *specs_scratch,
87 struct bpf_core_relo_res *targ_res);
88
89 int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
90 int insn_idx, const struct bpf_core_relo *relo,
91 int relo_idx, const struct bpf_core_relo_res *res);
92
93 int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
94 const struct bpf_core_relo *relo,
95 struct bpf_core_spec *spec);
96
97 int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *spec);
98
99 #endif
100
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.