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
9 struct btf;
10 struct btf_member;
11 struct btf_type;
12 union bpf_attr;
13
14 extern const struct file_operations btf_fops;
15
16 void btf_put(struct btf *btf);
17 int btf_new_fd(const union bpf_attr *attr);
18 struct btf *btf_get_by_fd(int fd);
19 int btf_get_info_by_fd(const struct btf *btf,
20 const union bpf_attr *attr,
21 union bpf_attr __user *uattr);
22 /* Figure out the size of a type_id. If type_id is a modifier
23 * (e.g. const), it will be resolved to find out the type with size.
24 *
25 * For example:
26 * In describing "const void *", type_id is "const" and "const"
27 * refers to "void *". The return type will be "void *".
28 *
29 * If type_id is a simple "int", then return type will be "int".
30 *
31 * @btf: struct btf object
32 * @type_id: Find out the size of type_id. The type_id of the return
33 * type is set to *type_id.
34 * @ret_size: It can be NULL. If not NULL, the size of the return
35 * type is set to *ret_size.
36 * Return: The btf_type (resolved to another type with size info if needed).
37 * NULL is returned if type_id itself does not have size info
38 * (e.g. void) or it cannot be resolved to another type that
39 * has size info.
40 * *type_id and *ret_size will not be changed in the
41 * NULL return case.
42 */
43 const struct btf_type *btf_type_id_size(const struct btf *btf,
44 u32 *type_id,
45 u32 *ret_size);
46 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
47 struct seq_file *m);
48 int btf_get_fd_by_id(u32 id);
49 u32 btf_id(const struct btf *btf);
50 bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
51 const struct btf_member *m,
52 u32 expected_offset, u32 expected_size);
53 int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
54 bool btf_type_is_void(const struct btf_type *t);
55
56 #ifdef CONFIG_BPF_SYSCALL
57 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
58 const char *btf_name_by_offset(const struct btf *btf, u32 offset);
59 #else
btf_type_by_id(const struct btf * btf,u32 type_id)60 static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
61 u32 type_id)
62 {
63 return NULL;
64 }
btf_name_by_offset(const struct btf * btf,u32 offset)65 static inline const char *btf_name_by_offset(const struct btf *btf,
66 u32 offset)
67 {
68 return NULL;
69 }
70 #endif
71
72 #endif
73