summaryrefslogtreecommitdiff
path: root/tools/lib/bpf/btf.h
blob: b18994116a44e141604f699499ef273b7c4dd27c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* Copyright (c) 2018 Facebook */

#ifndef __LIBBPF_BTF_H
#define __LIBBPF_BTF_H

#include <stdarg.h>
#include <linux/btf.h>
#include <linux/types.h>

#ifdef __cplusplus
extern "C" {
#endif

#ifndef LIBBPF_API
#define LIBBPF_API __attribute__((visibility("default")))
#endif

#define BTF_ELF_SEC ".BTF"
#define BTF_EXT_ELF_SEC ".BTF.ext"
#define MAPS_ELF_SEC ".maps"

struct btf;
struct btf_ext;
struct btf_type;

struct bpf_object;

/*
 * The .BTF.ext ELF section layout defined as
 *   struct btf_ext_header
 *   func_info subsection
 *
 * The func_info subsection layout:
 *   record size for struct bpf_func_info in the func_info subsection
 *   struct btf_sec_func_info for section #1
 *   a list of bpf_func_info records for section #1
 *     where struct bpf_func_info mimics one in include/uapi/linux/bpf.h
 *     but may not be identical
 *   struct btf_sec_func_info for section #2
 *   a list of bpf_func_info records for section #2
 *   ......
 *
 * Note that the bpf_func_info record size in .BTF.ext may not
 * be the same as the one defined in include/uapi/linux/bpf.h.
 * The loader should ensure that record_size meets minimum
 * requirement and pass the record as is to the kernel. The
 * kernel will handle the func_info properly based on its contents.
 */
struct btf_ext_header {
	__u16	magic;
	__u8	version;
	__u8	flags;
	__u32	hdr_len;

	/* All offsets are in bytes relative to the end of this header */
	__u32	func_info_off;
	__u32	func_info_len;
	__u32	line_info_off;
	__u32	line_info_len;

	/* optional part of .BTF.ext header */
	__u32	field_reloc_off;
	__u32	field_reloc_len;
};

LIBBPF_API void btf__free(struct btf *btf);
LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size);
LIBBPF_API struct btf *btf__parse_elf(const char *path,
				      struct btf_ext **btf_ext);
LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
LIBBPF_API int btf__load(struct btf *btf);
LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
				   const char *type_name);
LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
						  __u32 id);
LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__fd(const struct btf *btf);
LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
				    __u32 expected_key_size,
				    __u32 expected_value_size,
				    __u32 *key_type_id, __u32 *value_type_id);

LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size);
LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext,
					     __u32 *size);
LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf,
					const struct btf_ext *btf_ext,
					const char *sec_name, __u32 insns_cnt,
					void **func_info, __u32 *cnt);
LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf,
					const struct btf_ext *btf_ext,
					const char *sec_name, __u32 insns_cnt,
					void **line_info, __u32 *cnt);
LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);

struct btf_dedup_opts {
	unsigned int dedup_table_size;
	bool dont_resolve_fwds;
};

LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
			  const struct btf_dedup_opts *opts);

struct btf_dump;

struct btf_dump_opts {
	void *ctx;
};

typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);

LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
					  const struct btf_ext *btf_ext,
					  const struct btf_dump_opts *opts,
					  btf_dump_printf_fn_t printf_fn);
LIBBPF_API void btf_dump__free(struct btf_dump *d);

LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);

/*
 * A set of helpers for easier BTF types handling
 */
static inline __u16 btf_kind(const struct btf_type *t)
{
	return BTF_INFO_KIND(t->info);
}

static inline __u16 btf_vlen(const struct btf_type *t)
{
	return BTF_INFO_VLEN(t->info);
}

static inline bool btf_kflag(const struct btf_type *t)
{
	return BTF_INFO_KFLAG(t->info);
}

static inline bool btf_is_int(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_INT;
}

static inline bool btf_is_ptr(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_PTR;
}

static inline bool btf_is_array(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_ARRAY;
}

static inline bool btf_is_struct(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_STRUCT;
}

static inline bool btf_is_union(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_UNION;
}

static inline bool btf_is_composite(const struct btf_type *t)
{
	__u16 kind = btf_kind(t);

	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
}

static inline bool btf_is_enum(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_ENUM;
}

static inline bool btf_is_fwd(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_FWD;
}

static inline bool btf_is_typedef(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_TYPEDEF;
}

static inline bool btf_is_volatile(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_VOLATILE;
}

static inline bool btf_is_const(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_CONST;
}

static inline bool btf_is_restrict(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_RESTRICT;
}

static inline bool btf_is_mod(const struct btf_type *t)
{
	__u16 kind = btf_kind(t);

	return kind == BTF_KIND_VOLATILE ||
	       kind == BTF_KIND_CONST ||
	       kind == BTF_KIND_RESTRICT;
}

static inline bool btf_is_func(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_FUNC;
}

static inline bool btf_is_func_proto(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_FUNC_PROTO;
}

static inline bool btf_is_var(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_VAR;
}

static inline bool btf_is_datasec(const struct btf_type *t)
{
	return btf_kind(t) == BTF_KIND_DATASEC;
}

static inline __u8 btf_int_encoding(const struct btf_type *t)
{
	return BTF_INT_ENCODING(*(__u32 *)(t + 1));
}

static inline __u8 btf_int_offset(const struct btf_type *t)
{
	return BTF_INT_OFFSET(*(__u32 *)(t + 1));
}

static inline __u8 btf_int_bits(const struct btf_type *t)
{
	return BTF_INT_BITS(*(__u32 *)(t + 1));
}

static inline struct btf_array *btf_array(const struct btf_type *t)
{
	return (struct btf_array *)(t + 1);
}

static inline struct btf_enum *btf_enum(const struct btf_type *t)
{
	return (struct btf_enum *)(t + 1);
}

static inline struct btf_member *btf_members(const struct btf_type *t)
{
	return (struct btf_member *)(t + 1);
}

/* Get bit offset of a member with specified index. */
static inline __u32 btf_member_bit_offset(const struct btf_type *t,
					  __u32 member_idx)
{
	const struct btf_member *m = btf_members(t) + member_idx;
	bool kflag = btf_kflag(t);

	return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
}
/*
 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
 * BTF_KIND_UNION. If member is not a bitfield, zero is returned.
 */
static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
					     __u32 member_idx)
{
	const struct btf_member *m = btf_members(t) + member_idx;
	bool kflag = btf_kflag(t);

	return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
}

static inline struct btf_param *btf_params(const struct btf_type *t)
{
	return (struct btf_param *)(t + 1);
}

static inline struct btf_var *btf_var(const struct btf_type *t)
{
	return (struct btf_var *)(t + 1);
}

static inline struct btf_var_secinfo *
btf_var_secinfos(const struct btf_type *t)
{
	return (struct btf_var_secinfo *)(t + 1);
}

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* __LIBBPF_BTF_H */