Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2/* Copyright (c) 2018 Facebook */
3
4#ifndef _LINUX_BTF_H
5#define _LINUX_BTF_H 1
6
7#include <linux/types.h>
8#include <uapi/linux/btf.h>
9
10#define BTF_TYPE_EMIT(type) ((void)(type *)0)
11
12struct btf;
13struct btf_member;
14struct btf_type;
15union bpf_attr;
16
17extern const struct file_operations btf_fops;
18
19void btf_put(struct btf *btf);
20int btf_new_fd(const union bpf_attr *attr);
21struct btf *btf_get_by_fd(int fd);
22int btf_get_info_by_fd(const struct btf *btf,
23 const union bpf_attr *attr,
24 union bpf_attr __user *uattr);
25/* Figure out the size of a type_id. If type_id is a modifier
26 * (e.g. const), it will be resolved to find out the type with size.
27 *
28 * For example:
29 * In describing "const void *", type_id is "const" and "const"
30 * refers to "void *". The return type will be "void *".
31 *
32 * If type_id is a simple "int", then return type will be "int".
33 *
34 * @btf: struct btf object
35 * @type_id: Find out the size of type_id. The type_id of the return
36 * type is set to *type_id.
37 * @ret_size: It can be NULL. If not NULL, the size of the return
38 * type is set to *ret_size.
39 * Return: The btf_type (resolved to another type with size info if needed).
40 * NULL is returned if type_id itself does not have size info
41 * (e.g. void) or it cannot be resolved to another type that
42 * has size info.
43 * *type_id and *ret_size will not be changed in the
44 * NULL return case.
45 */
46const struct btf_type *btf_type_id_size(const struct btf *btf,
47 u32 *type_id,
48 u32 *ret_size);
49void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
50 struct seq_file *m);
51int btf_get_fd_by_id(u32 id);
52u32 btf_id(const struct btf *btf);
53bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
54 const struct btf_member *m,
55 u32 expected_offset, u32 expected_size);
56int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
57bool btf_type_is_void(const struct btf_type *t);
58s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
59const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
60 u32 id, u32 *res_id);
61const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
62 u32 id, u32 *res_id);
63const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
64 u32 id, u32 *res_id);
65const struct btf_type *
66btf_resolve_size(const struct btf *btf, const struct btf_type *type,
67 u32 *type_size, const struct btf_type **elem_type,
68 u32 *total_nelems);
69
70#define for_each_member(i, struct_type, member) \
71 for (i = 0, member = btf_type_member(struct_type); \
72 i < btf_type_vlen(struct_type); \
73 i++, member++)
74
75static inline bool btf_type_is_ptr(const struct btf_type *t)
76{
77 return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
78}
79
80static inline bool btf_type_is_int(const struct btf_type *t)
81{
82 return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
83}
84
85static inline bool btf_type_is_small_int(const struct btf_type *t)
86{
87 return btf_type_is_int(t) && t->size <= sizeof(u64);
88}
89
90static inline bool btf_type_is_enum(const struct btf_type *t)
91{
92 return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
93}
94
95static inline bool btf_type_is_typedef(const struct btf_type *t)
96{
97 return BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF;
98}
99
100static inline bool btf_type_is_func(const struct btf_type *t)
101{
102 return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC;
103}
104
105static inline bool btf_type_is_func_proto(const struct btf_type *t)
106{
107 return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
108}
109
110static inline u16 btf_type_vlen(const struct btf_type *t)
111{
112 return BTF_INFO_VLEN(t->info);
113}
114
115static inline u16 btf_func_linkage(const struct btf_type *t)
116{
117 return BTF_INFO_VLEN(t->info);
118}
119
120static inline bool btf_type_kflag(const struct btf_type *t)
121{
122 return BTF_INFO_KFLAG(t->info);
123}
124
125static inline u32 btf_member_bit_offset(const struct btf_type *struct_type,
126 const struct btf_member *member)
127{
128 return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
129 : member->offset;
130}
131
132static inline u32 btf_member_bitfield_size(const struct btf_type *struct_type,
133 const struct btf_member *member)
134{
135 return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
136 : 0;
137}
138
139static inline const struct btf_member *btf_type_member(const struct btf_type *t)
140{
141 return (const struct btf_member *)(t + 1);
142}
143
144#ifdef CONFIG_BPF_SYSCALL
145const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
146const char *btf_name_by_offset(const struct btf *btf, u32 offset);
147struct btf *btf_parse_vmlinux(void);
148struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog);
149#else
150static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
151 u32 type_id)
152{
153 return NULL;
154}
155static inline const char *btf_name_by_offset(const struct btf *btf,
156 u32 offset)
157{
158 return NULL;
159}
160#endif
161
162#endif