blob: 92940ae26ada301605ed7465f7dcb1c3643b53fe [file] [log] [blame]
David Brazdil0f672f62019-12-10 10:32:29 +00001/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2
3/*
4 * Internal libbpf helpers.
5 *
6 * Copyright (c) 2019 Facebook
7 */
8
9#ifndef __LIBBPF_LIBBPF_INTERNAL_H
10#define __LIBBPF_LIBBPF_INTERNAL_H
11
12#include "libbpf.h"
13
14#define BTF_INFO_ENC(kind, kind_flag, vlen) \
15 ((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN))
16#define BTF_TYPE_ENC(name, info, size_or_type) (name), (info), (size_or_type)
17#define BTF_INT_ENC(encoding, bits_offset, nr_bits) \
18 ((encoding) << 24 | (bits_offset) << 16 | (nr_bits))
19#define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \
20 BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \
21 BTF_INT_ENC(encoding, bits_offset, bits)
22#define BTF_MEMBER_ENC(name, type, bits_offset) (name), (type), (bits_offset)
23#define BTF_PARAM_ENC(name, type) (name), (type)
24#define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size)
25
26#ifndef min
27# define min(x, y) ((x) < (y) ? (x) : (y))
28#endif
29#ifndef max
30# define max(x, y) ((x) < (y) ? (y) : (x))
31#endif
32#ifndef offsetofend
33# define offsetofend(TYPE, FIELD) \
34 (offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD))
35#endif
36
37/* Symbol versioning is different between static and shared library.
38 * Properly versioned symbols are needed for shared library, but
39 * only the symbol of the new version is needed for static library.
40 */
41#ifdef SHARED
42# define COMPAT_VERSION(internal_name, api_name, version) \
43 asm(".symver " #internal_name "," #api_name "@" #version);
44# define DEFAULT_VERSION(internal_name, api_name, version) \
45 asm(".symver " #internal_name "," #api_name "@@" #version);
46#else
47# define COMPAT_VERSION(internal_name, api_name, version)
48# define DEFAULT_VERSION(internal_name, api_name, version) \
49 extern typeof(internal_name) api_name \
50 __attribute__((alias(#internal_name)));
51#endif
52
53extern void libbpf_print(enum libbpf_print_level level,
54 const char *format, ...)
55 __attribute__((format(printf, 2, 3)));
56
57#define __pr(level, fmt, ...) \
58do { \
59 libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \
60} while (0)
61
62#define pr_warning(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__)
63#define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__)
64#define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__)
65
Olivier Deprez0e641232021-09-23 10:07:05 +020066int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz);
67int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz);
David Brazdil0f672f62019-12-10 10:32:29 +000068int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
69 const char *str_sec, size_t str_len);
70
71struct btf_ext_info {
72 /*
73 * info points to the individual info section (e.g. func_info and
74 * line_info) from the .BTF.ext. It does not include the __u32 rec_size.
75 */
76 void *info;
77 __u32 rec_size;
78 __u32 len;
79};
80
81#define for_each_btf_ext_sec(seg, sec) \
82 for (sec = (seg)->info; \
83 (void *)sec < (seg)->info + (seg)->len; \
84 sec = (void *)sec + sizeof(struct btf_ext_info_sec) + \
85 (seg)->rec_size * sec->num_info)
86
87#define for_each_btf_ext_rec(seg, sec, i, rec) \
88 for (i = 0, rec = (void *)&(sec)->data; \
89 i < (sec)->num_info; \
90 i++, rec = (void *)rec + (seg)->rec_size)
91
92struct btf_ext {
93 union {
94 struct btf_ext_header *hdr;
95 void *data;
96 };
97 struct btf_ext_info func_info;
98 struct btf_ext_info line_info;
99 struct btf_ext_info offset_reloc_info;
100 __u32 data_size;
101};
102
103struct btf_ext_info_sec {
104 __u32 sec_name_off;
105 __u32 num_info;
106 /* Followed by num_info * record_size number of bytes */
107 __u8 data[0];
108};
109
110/* The minimum bpf_func_info checked by the loader */
111struct bpf_func_info_min {
112 __u32 insn_off;
113 __u32 type_id;
114};
115
116/* The minimum bpf_line_info checked by the loader */
117struct bpf_line_info_min {
118 __u32 insn_off;
119 __u32 file_name_off;
120 __u32 line_off;
121 __u32 line_col;
122};
123
124/* The minimum bpf_offset_reloc checked by the loader
125 *
126 * Offset relocation captures the following data:
127 * - insn_off - instruction offset (in bytes) within a BPF program that needs
128 * its insn->imm field to be relocated with actual offset;
129 * - type_id - BTF type ID of the "root" (containing) entity of a relocatable
130 * offset;
131 * - access_str_off - offset into corresponding .BTF string section. String
132 * itself encodes an accessed field using a sequence of field and array
133 * indicies, separated by colon (:). It's conceptually very close to LLVM's
134 * getelementptr ([0]) instruction's arguments for identifying offset to
135 * a field.
136 *
137 * Example to provide a better feel.
138 *
139 * struct sample {
140 * int a;
141 * struct {
142 * int b[10];
143 * };
144 * };
145 *
146 * struct sample *s = ...;
147 * int x = &s->a; // encoded as "0:0" (a is field #0)
148 * int y = &s->b[5]; // encoded as "0:1:0:5" (anon struct is field #1,
149 * // b is field #0 inside anon struct, accessing elem #5)
150 * int z = &s[10]->b; // encoded as "10:1" (ptr is used as an array)
151 *
152 * type_id for all relocs in this example will capture BTF type id of
153 * `struct sample`.
154 *
155 * Such relocation is emitted when using __builtin_preserve_access_index()
156 * Clang built-in, passing expression that captures field address, e.g.:
157 *
158 * bpf_probe_read(&dst, sizeof(dst),
159 * __builtin_preserve_access_index(&src->a.b.c));
160 *
161 * In this case Clang will emit offset relocation recording necessary data to
162 * be able to find offset of embedded `a.b.c` field within `src` struct.
163 *
164 * [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction
165 */
166struct bpf_offset_reloc {
167 __u32 insn_off;
168 __u32 type_id;
169 __u32 access_str_off;
170};
171
172#endif /* __LIBBPF_LIBBPF_INTERNAL_H */