1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
  2/* Copyright (c) 2018 Facebook */
  3
  4#ifndef __LIBBPF_BTF_H
  5#define __LIBBPF_BTF_H
  6
  7#include <stdarg.h>
  8#include <linux/btf.h>
  9#include <linux/types.h>
 10
 11#ifdef __cplusplus
 12extern "C" {
 13#endif
 14
 15#ifndef LIBBPF_API
 16#define LIBBPF_API __attribute__((visibility("default")))
 17#endif
 18
 19#define BTF_ELF_SEC ".BTF"
 20#define BTF_EXT_ELF_SEC ".BTF.ext"
 21#define MAPS_ELF_SEC ".maps"
 22
 23struct btf;
 24struct btf_ext;
 25struct btf_type;
 26
 27struct bpf_object;
 28
 29/*
 30 * The .BTF.ext ELF section layout defined as
 31 *   struct btf_ext_header
 32 *   func_info subsection
 33 *
 34 * The func_info subsection layout:
 35 *   record size for struct bpf_func_info in the func_info subsection
 36 *   struct btf_sec_func_info for section #1
 37 *   a list of bpf_func_info records for section #1
 38 *     where struct bpf_func_info mimics one in include/uapi/linux/bpf.h
 39 *     but may not be identical
 40 *   struct btf_sec_func_info for section #2
 41 *   a list of bpf_func_info records for section #2
 42 *   ......
 43 *
 44 * Note that the bpf_func_info record size in .BTF.ext may not
 45 * be the same as the one defined in include/uapi/linux/bpf.h.
 46 * The loader should ensure that record_size meets minimum
 47 * requirement and pass the record as is to the kernel. The
 48 * kernel will handle the func_info properly based on its contents.
 49 */
 50struct btf_ext_header {
 51	__u16	magic;
 52	__u8	version;
 53	__u8	flags;
 54	__u32	hdr_len;
 55
 56	/* All offsets are in bytes relative to the end of this header */
 57	__u32	func_info_off;
 58	__u32	func_info_len;
 59	__u32	line_info_off;
 60	__u32	line_info_len;
 61
 62	/* optional part of .BTF.ext header */
 63	__u32	offset_reloc_off;
 64	__u32	offset_reloc_len;
 65};
 66
 67LIBBPF_API void btf__free(struct btf *btf);
 68LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size);
 69LIBBPF_API struct btf *btf__parse_elf(const char *path,
 70				      struct btf_ext **btf_ext);
 71LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
 72LIBBPF_API int btf__load(struct btf *btf);
 73LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
 74				   const char *type_name);
 75LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
 76LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
 77						  __u32 id);
 78LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
 79LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
 80LIBBPF_API int btf__fd(const struct btf *btf);
 81LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
 82LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
 83LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
 84LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
 85				    __u32 expected_key_size,
 86				    __u32 expected_value_size,
 87				    __u32 *key_type_id, __u32 *value_type_id);
 88
 89LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size);
 90LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
 91LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext,
 92					     __u32 *size);
 93LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf,
 94					const struct btf_ext *btf_ext,
 95					const char *sec_name, __u32 insns_cnt,
 96					void **func_info, __u32 *cnt);
 97LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf,
 98					const struct btf_ext *btf_ext,
 99					const char *sec_name, __u32 insns_cnt,
100					void **line_info, __u32 *cnt);
101LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
102LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
103
104struct btf_dedup_opts {
105	unsigned int dedup_table_size;
106	bool dont_resolve_fwds;
107};
108
109LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
110			  const struct btf_dedup_opts *opts);
111
112struct btf_dump;
113
114struct btf_dump_opts {
115	void *ctx;
116};
117
118typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
119
120LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
121					  const struct btf_ext *btf_ext,
122					  const struct btf_dump_opts *opts,
123					  btf_dump_printf_fn_t printf_fn);
124LIBBPF_API void btf_dump__free(struct btf_dump *d);
125
126LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
127
128/*
129 * A set of helpers for easier BTF types handling
130 */
131static inline __u16 btf_kind(const struct btf_type *t)
132{
133	return BTF_INFO_KIND(t->info);
134}
135
136static inline __u16 btf_vlen(const struct btf_type *t)
137{
138	return BTF_INFO_VLEN(t->info);
139}
140
141static inline bool btf_kflag(const struct btf_type *t)
142{
143	return BTF_INFO_KFLAG(t->info);
144}
145
146static inline bool btf_is_int(const struct btf_type *t)
147{
148	return btf_kind(t) == BTF_KIND_INT;
149}
150
151static inline bool btf_is_ptr(const struct btf_type *t)
152{
153	return btf_kind(t) == BTF_KIND_PTR;
154}
155
156static inline bool btf_is_array(const struct btf_type *t)
157{
158	return btf_kind(t) == BTF_KIND_ARRAY;
159}
160
161static inline bool btf_is_struct(const struct btf_type *t)
162{
163	return btf_kind(t) == BTF_KIND_STRUCT;
164}
165
166static inline bool btf_is_union(const struct btf_type *t)
167{
168	return btf_kind(t) == BTF_KIND_UNION;
169}
170
171static inline bool btf_is_composite(const struct btf_type *t)
172{
173	__u16 kind = btf_kind(t);
174
175	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
176}
177
178static inline bool btf_is_enum(const struct btf_type *t)
179{
180	return btf_kind(t) == BTF_KIND_ENUM;
181}
182
183static inline bool btf_is_fwd(const struct btf_type *t)
184{
185	return btf_kind(t) == BTF_KIND_FWD;
186}
187
188static inline bool btf_is_typedef(const struct btf_type *t)
189{
190	return btf_kind(t) == BTF_KIND_TYPEDEF;
191}
192
193static inline bool btf_is_volatile(const struct btf_type *t)
194{
195	return btf_kind(t) == BTF_KIND_VOLATILE;
196}
197
198static inline bool btf_is_const(const struct btf_type *t)
199{
200	return btf_kind(t) == BTF_KIND_CONST;
201}
202
203static inline bool btf_is_restrict(const struct btf_type *t)
204{
205	return btf_kind(t) == BTF_KIND_RESTRICT;
206}
207
208static inline bool btf_is_mod(const struct btf_type *t)
209{
210	__u16 kind = btf_kind(t);
211
212	return kind == BTF_KIND_VOLATILE ||
213	       kind == BTF_KIND_CONST ||
214	       kind == BTF_KIND_RESTRICT;
215}
216
217static inline bool btf_is_func(const struct btf_type *t)
218{
219	return btf_kind(t) == BTF_KIND_FUNC;
220}
221
222static inline bool btf_is_func_proto(const struct btf_type *t)
223{
224	return btf_kind(t) == BTF_KIND_FUNC_PROTO;
225}
226
227static inline bool btf_is_var(const struct btf_type *t)
228{
229	return btf_kind(t) == BTF_KIND_VAR;
230}
231
232static inline bool btf_is_datasec(const struct btf_type *t)
233{
234	return btf_kind(t) == BTF_KIND_DATASEC;
235}
236
237static inline __u8 btf_int_encoding(const struct btf_type *t)
238{
239	return BTF_INT_ENCODING(*(__u32 *)(t + 1));
240}
241
242static inline __u8 btf_int_offset(const struct btf_type *t)
243{
244	return BTF_INT_OFFSET(*(__u32 *)(t + 1));
245}
246
247static inline __u8 btf_int_bits(const struct btf_type *t)
248{
249	return BTF_INT_BITS(*(__u32 *)(t + 1));
250}
251
252static inline struct btf_array *btf_array(const struct btf_type *t)
253{
254	return (struct btf_array *)(t + 1);
255}
256
257static inline struct btf_enum *btf_enum(const struct btf_type *t)
258{
259	return (struct btf_enum *)(t + 1);
260}
261
262static inline struct btf_member *btf_members(const struct btf_type *t)
263{
264	return (struct btf_member *)(t + 1);
265}
266
267/* Get bit offset of a member with specified index. */
268static inline __u32 btf_member_bit_offset(const struct btf_type *t,
269					  __u32 member_idx)
270{
271	const struct btf_member *m = btf_members(t) + member_idx;
272	bool kflag = btf_kflag(t);
273
274	return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
275}
276/*
277 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
278 * BTF_KIND_UNION. If member is not a bitfield, zero is returned.
279 */
280static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
281					     __u32 member_idx)
282{
283	const struct btf_member *m = btf_members(t) + member_idx;
284	bool kflag = btf_kflag(t);
285
286	return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
287}
288
289static inline struct btf_param *btf_params(const struct btf_type *t)
290{
291	return (struct btf_param *)(t + 1);
292}
293
294static inline struct btf_var *btf_var(const struct btf_type *t)
295{
296	return (struct btf_var *)(t + 1);
297}
298
299static inline struct btf_var_secinfo *
300btf_var_secinfos(const struct btf_type *t)
301{
302	return (struct btf_var_secinfo *)(t + 1);
303}
304
305#ifdef __cplusplus
306} /* extern "C" */
307#endif
308
309#endif /* __LIBBPF_BTF_H */