xref: /openbmc/linux/tools/lib/bpf/btf.h (revision 0760aad038b5a032c31ea124feed63d88627d2f1)
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 #include "libbpf_common.h"
12 
13 #ifdef __cplusplus
14 extern "C" {
15 #endif
16 
17 #define BTF_ELF_SEC ".BTF"
18 #define BTF_EXT_ELF_SEC ".BTF.ext"
19 #define MAPS_ELF_SEC ".maps"
20 
21 struct btf;
22 struct btf_ext;
23 struct btf_type;
24 
25 struct bpf_object;
26 
27 LIBBPF_API void btf__free(struct btf *btf);
28 LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
29 LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
30 LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
31 LIBBPF_API struct btf *btf__parse_raw(const char *path);
32 LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
33 LIBBPF_API int btf__load(struct btf *btf);
34 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
35 				   const char *type_name);
36 LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
37 					const char *type_name, __u32 kind);
38 LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
39 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
40 						  __u32 id);
41 LIBBPF_API size_t btf__pointer_size(const struct btf *btf);
42 LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz);
43 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
44 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
45 LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
46 LIBBPF_API int btf__fd(const struct btf *btf);
47 LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
48 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
49 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
50 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
51 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
52 				    __u32 expected_key_size,
53 				    __u32 expected_value_size,
54 				    __u32 *key_type_id, __u32 *value_type_id);
55 
56 LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size);
57 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
58 LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext,
59 					     __u32 *size);
60 LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf,
61 					const struct btf_ext *btf_ext,
62 					const char *sec_name, __u32 insns_cnt,
63 					void **func_info, __u32 *cnt);
64 LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf,
65 					const struct btf_ext *btf_ext,
66 					const char *sec_name, __u32 insns_cnt,
67 					void **line_info, __u32 *cnt);
68 LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
69 LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
70 
71 LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
72 
73 struct btf_dedup_opts {
74 	unsigned int dedup_table_size;
75 	bool dont_resolve_fwds;
76 };
77 
78 LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
79 			  const struct btf_dedup_opts *opts);
80 
81 struct btf_dump;
82 
83 struct btf_dump_opts {
84 	void *ctx;
85 };
86 
87 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
88 
89 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
90 					  const struct btf_ext *btf_ext,
91 					  const struct btf_dump_opts *opts,
92 					  btf_dump_printf_fn_t printf_fn);
93 LIBBPF_API void btf_dump__free(struct btf_dump *d);
94 
95 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
96 
97 struct btf_dump_emit_type_decl_opts {
98 	/* size of this struct, for forward/backward compatiblity */
99 	size_t sz;
100 	/* optional field name for type declaration, e.g.:
101 	 * - struct my_struct <FNAME>
102 	 * - void (*<FNAME>)(int)
103 	 * - char (*<FNAME>)[123]
104 	 */
105 	const char *field_name;
106 	/* extra indentation level (in number of tabs) to emit for multi-line
107 	 * type declarations (e.g., anonymous struct); applies for lines
108 	 * starting from the second one (first line is assumed to have
109 	 * necessary indentation already
110 	 */
111 	int indent_level;
112 	/* strip all the const/volatile/restrict mods */
113 	bool strip_mods;
114 };
115 #define btf_dump_emit_type_decl_opts__last_field strip_mods
116 
117 LIBBPF_API int
118 btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
119 			 const struct btf_dump_emit_type_decl_opts *opts);
120 
121 /*
122  * A set of helpers for easier BTF types handling
123  */
124 static inline __u16 btf_kind(const struct btf_type *t)
125 {
126 	return BTF_INFO_KIND(t->info);
127 }
128 
129 static inline __u16 btf_vlen(const struct btf_type *t)
130 {
131 	return BTF_INFO_VLEN(t->info);
132 }
133 
134 static inline bool btf_kflag(const struct btf_type *t)
135 {
136 	return BTF_INFO_KFLAG(t->info);
137 }
138 
139 static inline bool btf_is_void(const struct btf_type *t)
140 {
141 	return btf_kind(t) == BTF_KIND_UNKN;
142 }
143 
144 static inline bool btf_is_int(const struct btf_type *t)
145 {
146 	return btf_kind(t) == BTF_KIND_INT;
147 }
148 
149 static inline bool btf_is_ptr(const struct btf_type *t)
150 {
151 	return btf_kind(t) == BTF_KIND_PTR;
152 }
153 
154 static inline bool btf_is_array(const struct btf_type *t)
155 {
156 	return btf_kind(t) == BTF_KIND_ARRAY;
157 }
158 
159 static inline bool btf_is_struct(const struct btf_type *t)
160 {
161 	return btf_kind(t) == BTF_KIND_STRUCT;
162 }
163 
164 static inline bool btf_is_union(const struct btf_type *t)
165 {
166 	return btf_kind(t) == BTF_KIND_UNION;
167 }
168 
169 static inline bool btf_is_composite(const struct btf_type *t)
170 {
171 	__u16 kind = btf_kind(t);
172 
173 	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
174 }
175 
176 static inline bool btf_is_enum(const struct btf_type *t)
177 {
178 	return btf_kind(t) == BTF_KIND_ENUM;
179 }
180 
181 static inline bool btf_is_fwd(const struct btf_type *t)
182 {
183 	return btf_kind(t) == BTF_KIND_FWD;
184 }
185 
186 static inline bool btf_is_typedef(const struct btf_type *t)
187 {
188 	return btf_kind(t) == BTF_KIND_TYPEDEF;
189 }
190 
191 static inline bool btf_is_volatile(const struct btf_type *t)
192 {
193 	return btf_kind(t) == BTF_KIND_VOLATILE;
194 }
195 
196 static inline bool btf_is_const(const struct btf_type *t)
197 {
198 	return btf_kind(t) == BTF_KIND_CONST;
199 }
200 
201 static inline bool btf_is_restrict(const struct btf_type *t)
202 {
203 	return btf_kind(t) == BTF_KIND_RESTRICT;
204 }
205 
206 static inline bool btf_is_mod(const struct btf_type *t)
207 {
208 	__u16 kind = btf_kind(t);
209 
210 	return kind == BTF_KIND_VOLATILE ||
211 	       kind == BTF_KIND_CONST ||
212 	       kind == BTF_KIND_RESTRICT;
213 }
214 
215 static inline bool btf_is_func(const struct btf_type *t)
216 {
217 	return btf_kind(t) == BTF_KIND_FUNC;
218 }
219 
220 static inline bool btf_is_func_proto(const struct btf_type *t)
221 {
222 	return btf_kind(t) == BTF_KIND_FUNC_PROTO;
223 }
224 
225 static inline bool btf_is_var(const struct btf_type *t)
226 {
227 	return btf_kind(t) == BTF_KIND_VAR;
228 }
229 
230 static inline bool btf_is_datasec(const struct btf_type *t)
231 {
232 	return btf_kind(t) == BTF_KIND_DATASEC;
233 }
234 
235 static inline __u8 btf_int_encoding(const struct btf_type *t)
236 {
237 	return BTF_INT_ENCODING(*(__u32 *)(t + 1));
238 }
239 
240 static inline __u8 btf_int_offset(const struct btf_type *t)
241 {
242 	return BTF_INT_OFFSET(*(__u32 *)(t + 1));
243 }
244 
245 static inline __u8 btf_int_bits(const struct btf_type *t)
246 {
247 	return BTF_INT_BITS(*(__u32 *)(t + 1));
248 }
249 
250 static inline struct btf_array *btf_array(const struct btf_type *t)
251 {
252 	return (struct btf_array *)(t + 1);
253 }
254 
255 static inline struct btf_enum *btf_enum(const struct btf_type *t)
256 {
257 	return (struct btf_enum *)(t + 1);
258 }
259 
260 static inline struct btf_member *btf_members(const struct btf_type *t)
261 {
262 	return (struct btf_member *)(t + 1);
263 }
264 
265 /* Get bit offset of a member with specified index. */
266 static inline __u32 btf_member_bit_offset(const struct btf_type *t,
267 					  __u32 member_idx)
268 {
269 	const struct btf_member *m = btf_members(t) + member_idx;
270 	bool kflag = btf_kflag(t);
271 
272 	return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
273 }
274 /*
275  * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
276  * BTF_KIND_UNION. If member is not a bitfield, zero is returned.
277  */
278 static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
279 					     __u32 member_idx)
280 {
281 	const struct btf_member *m = btf_members(t) + member_idx;
282 	bool kflag = btf_kflag(t);
283 
284 	return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
285 }
286 
287 static inline struct btf_param *btf_params(const struct btf_type *t)
288 {
289 	return (struct btf_param *)(t + 1);
290 }
291 
292 static inline struct btf_var *btf_var(const struct btf_type *t)
293 {
294 	return (struct btf_var *)(t + 1);
295 }
296 
297 static inline struct btf_var_secinfo *
298 btf_var_secinfos(const struct btf_type *t)
299 {
300 	return (struct btf_var_secinfo *)(t + 1);
301 }
302 
303 #ifdef __cplusplus
304 } /* extern "C" */
305 #endif
306 
307 #endif /* __LIBBPF_BTF_H */
308