1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 2 /* Copyright (c) 2018 Facebook */ 3 /*! \file */ 4 5 #ifndef __LIBBPF_BTF_H 6 #define __LIBBPF_BTF_H 7 8 #include <stdarg.h> 9 #include <stdbool.h> 10 #include <linux/btf.h> 11 #include <linux/types.h> 12 13 #include "libbpf_common.h" 14 15 #ifdef __cplusplus 16 extern "C" { 17 #endif 18 19 #define BTF_ELF_SEC ".BTF" 20 #define BTF_EXT_ELF_SEC ".BTF.ext" 21 #define MAPS_ELF_SEC ".maps" 22 23 struct btf; 24 struct btf_ext; 25 struct btf_type; 26 27 struct bpf_object; 28 29 enum btf_endianness { 30 BTF_LITTLE_ENDIAN = 0, 31 BTF_BIG_ENDIAN = 1, 32 }; 33 34 /** 35 * @brief **btf__free()** frees all data of a BTF object 36 * @param btf BTF object to free 37 */ 38 LIBBPF_API void btf__free(struct btf *btf); 39 40 /** 41 * @brief **btf__new()** creates a new instance of a BTF object from the raw 42 * bytes of an ELF's BTF section 43 * @param data raw bytes 44 * @param size number of bytes passed in `data` 45 * @return new BTF object instance which has to be eventually freed with 46 * **btf__free()** 47 * 48 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract 49 * error code from such a pointer `libbpf_get_error()` should be used. If 50 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is 51 * returned on error instead. In both cases thread-local `errno` variable is 52 * always set to error code as well. 53 */ 54 LIBBPF_API struct btf *btf__new(const void *data, __u32 size); 55 56 /** 57 * @brief **btf__new_split()** create a new instance of a BTF object from the 58 * provided raw data bytes. It takes another BTF instance, **base_btf**, which 59 * serves as a base BTF, which is extended by types in a newly created BTF 60 * instance 61 * @param data raw bytes 62 * @param size length of raw bytes 63 * @param base_btf the base BTF object 64 * @return new BTF object instance which has to be eventually freed with 65 * **btf__free()** 66 * 67 * If *base_btf* is NULL, `btf__new_split()` is equivalent to `btf__new()` and 68 * creates non-split BTF. 69 * 70 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract 71 * error code from such a pointer `libbpf_get_error()` should be used. If 72 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is 73 * returned on error instead. In both cases thread-local `errno` variable is 74 * always set to error code as well. 75 */ 76 LIBBPF_API struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf); 77 78 /** 79 * @brief **btf__new_empty()** creates an empty BTF object. Use 80 * `btf__add_*()` to populate such BTF object. 81 * @return new BTF object instance which has to be eventually freed with 82 * **btf__free()** 83 * 84 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract 85 * error code from such a pointer `libbpf_get_error()` should be used. If 86 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is 87 * returned on error instead. In both cases thread-local `errno` variable is 88 * always set to error code as well. 89 */ 90 LIBBPF_API struct btf *btf__new_empty(void); 91 92 /** 93 * @brief **btf__new_empty_split()** creates an unpopulated BTF object from an 94 * ELF BTF section except with a base BTF on top of which split BTF should be 95 * based 96 * @return new BTF object instance which has to be eventually freed with 97 * **btf__free()** 98 * 99 * If *base_btf* is NULL, `btf__new_empty_split()` is equivalent to 100 * `btf__new_empty()` and creates non-split BTF. 101 * 102 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract 103 * error code from such a pointer `libbpf_get_error()` should be used. If 104 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is 105 * returned on error instead. In both cases thread-local `errno` variable is 106 * always set to error code as well. 107 */ 108 LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf); 109 110 LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext); 111 LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf); 112 LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext); 113 LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf); 114 LIBBPF_API struct btf *btf__parse_raw(const char *path); 115 LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf); 116 117 LIBBPF_API struct btf *btf__load_vmlinux_btf(void); 118 LIBBPF_API struct btf *btf__load_module_btf(const char *module_name, struct btf *vmlinux_btf); 119 LIBBPF_API struct btf *libbpf_find_kernel_btf(void); 120 121 LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id); 122 LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf); 123 LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_from_kernel_by_id instead") 124 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); 125 126 LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); 127 LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_into_kernel instead") 128 LIBBPF_API int btf__load(struct btf *btf); 129 LIBBPF_API int btf__load_into_kernel(struct btf *btf); 130 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, 131 const char *type_name); 132 LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf, 133 const char *type_name, __u32 kind); 134 LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf); 135 LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf); 136 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf, 137 __u32 id); 138 LIBBPF_API size_t btf__pointer_size(const struct btf *btf); 139 LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz); 140 LIBBPF_API enum btf_endianness btf__endianness(const struct btf *btf); 141 LIBBPF_API int btf__set_endianness(struct btf *btf, enum btf_endianness endian); 142 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id); 143 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); 144 LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id); 145 LIBBPF_API int btf__fd(const struct btf *btf); 146 LIBBPF_API void btf__set_fd(struct btf *btf, int fd); 147 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size); 148 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); 149 LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset); 150 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, 151 __u32 expected_key_size, 152 __u32 expected_value_size, 153 __u32 *key_type_id, __u32 *value_type_id); 154 155 LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size); 156 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext); 157 LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, 158 __u32 *size); 159 LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_func_info was never meant as a public API and has wrong assumptions embedded in it; it will be removed in the future libbpf versions") 160 int btf_ext__reloc_func_info(const struct btf *btf, 161 const struct btf_ext *btf_ext, 162 const char *sec_name, __u32 insns_cnt, 163 void **func_info, __u32 *cnt); 164 LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_line_info was never meant as a public API and has wrong assumptions embedded in it; it will be removed in the future libbpf versions") 165 int btf_ext__reloc_line_info(const struct btf *btf, 166 const struct btf_ext *btf_ext, 167 const char *sec_name, __u32 insns_cnt, 168 void **line_info, __u32 *cnt); 169 LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext); 170 LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext); 171 172 LIBBPF_API int btf__find_str(struct btf *btf, const char *s); 173 LIBBPF_API int btf__add_str(struct btf *btf, const char *s); 174 LIBBPF_API int btf__add_type(struct btf *btf, const struct btf *src_btf, 175 const struct btf_type *src_type); 176 177 LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding); 178 LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz); 179 LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id); 180 LIBBPF_API int btf__add_array(struct btf *btf, 181 int index_type_id, int elem_type_id, __u32 nr_elems); 182 /* struct/union construction APIs */ 183 LIBBPF_API int btf__add_struct(struct btf *btf, const char *name, __u32 sz); 184 LIBBPF_API int btf__add_union(struct btf *btf, const char *name, __u32 sz); 185 LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_id, 186 __u32 bit_offset, __u32 bit_size); 187 188 /* enum construction APIs */ 189 LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz); 190 LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value); 191 192 enum btf_fwd_kind { 193 BTF_FWD_STRUCT = 0, 194 BTF_FWD_UNION = 1, 195 BTF_FWD_ENUM = 2, 196 }; 197 198 LIBBPF_API int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind); 199 LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id); 200 LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id); 201 LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id); 202 LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id); 203 204 /* func and func_proto construction APIs */ 205 LIBBPF_API int btf__add_func(struct btf *btf, const char *name, 206 enum btf_func_linkage linkage, int proto_type_id); 207 LIBBPF_API int btf__add_func_proto(struct btf *btf, int ret_type_id); 208 LIBBPF_API int btf__add_func_param(struct btf *btf, const char *name, int type_id); 209 210 /* var & datasec construction APIs */ 211 LIBBPF_API int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id); 212 LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz); 213 LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id, 214 __u32 offset, __u32 byte_sz); 215 216 /* tag construction API */ 217 LIBBPF_API int btf__add_tag(struct btf *btf, const char *value, int ref_type_id, 218 int component_idx); 219 220 struct btf_dedup_opts { 221 unsigned int dedup_table_size; 222 bool dont_resolve_fwds; 223 }; 224 225 LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, 226 const struct btf_dedup_opts *opts); 227 228 struct btf_dump; 229 230 struct btf_dump_opts { 231 void *ctx; 232 }; 233 234 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args); 235 236 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf, 237 const struct btf_ext *btf_ext, 238 const struct btf_dump_opts *opts, 239 btf_dump_printf_fn_t printf_fn); 240 LIBBPF_API void btf_dump__free(struct btf_dump *d); 241 242 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id); 243 244 struct btf_dump_emit_type_decl_opts { 245 /* size of this struct, for forward/backward compatiblity */ 246 size_t sz; 247 /* optional field name for type declaration, e.g.: 248 * - struct my_struct <FNAME> 249 * - void (*<FNAME>)(int) 250 * - char (*<FNAME>)[123] 251 */ 252 const char *field_name; 253 /* extra indentation level (in number of tabs) to emit for multi-line 254 * type declarations (e.g., anonymous struct); applies for lines 255 * starting from the second one (first line is assumed to have 256 * necessary indentation already 257 */ 258 int indent_level; 259 /* strip all the const/volatile/restrict mods */ 260 bool strip_mods; 261 size_t :0; 262 }; 263 #define btf_dump_emit_type_decl_opts__last_field strip_mods 264 265 LIBBPF_API int 266 btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, 267 const struct btf_dump_emit_type_decl_opts *opts); 268 269 270 struct btf_dump_type_data_opts { 271 /* size of this struct, for forward/backward compatibility */ 272 size_t sz; 273 const char *indent_str; 274 int indent_level; 275 /* below match "show" flags for bpf_show_snprintf() */ 276 bool compact; /* no newlines/indentation */ 277 bool skip_names; /* skip member/type names */ 278 bool emit_zeroes; /* show 0-valued fields */ 279 size_t :0; 280 }; 281 #define btf_dump_type_data_opts__last_field emit_zeroes 282 283 LIBBPF_API int 284 btf_dump__dump_type_data(struct btf_dump *d, __u32 id, 285 const void *data, size_t data_sz, 286 const struct btf_dump_type_data_opts *opts); 287 288 /* 289 * A set of helpers for easier BTF types handling 290 */ 291 static inline __u16 btf_kind(const struct btf_type *t) 292 { 293 return BTF_INFO_KIND(t->info); 294 } 295 296 static inline __u16 btf_vlen(const struct btf_type *t) 297 { 298 return BTF_INFO_VLEN(t->info); 299 } 300 301 static inline bool btf_kflag(const struct btf_type *t) 302 { 303 return BTF_INFO_KFLAG(t->info); 304 } 305 306 static inline bool btf_is_void(const struct btf_type *t) 307 { 308 return btf_kind(t) == BTF_KIND_UNKN; 309 } 310 311 static inline bool btf_is_int(const struct btf_type *t) 312 { 313 return btf_kind(t) == BTF_KIND_INT; 314 } 315 316 static inline bool btf_is_ptr(const struct btf_type *t) 317 { 318 return btf_kind(t) == BTF_KIND_PTR; 319 } 320 321 static inline bool btf_is_array(const struct btf_type *t) 322 { 323 return btf_kind(t) == BTF_KIND_ARRAY; 324 } 325 326 static inline bool btf_is_struct(const struct btf_type *t) 327 { 328 return btf_kind(t) == BTF_KIND_STRUCT; 329 } 330 331 static inline bool btf_is_union(const struct btf_type *t) 332 { 333 return btf_kind(t) == BTF_KIND_UNION; 334 } 335 336 static inline bool btf_is_composite(const struct btf_type *t) 337 { 338 __u16 kind = btf_kind(t); 339 340 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; 341 } 342 343 static inline bool btf_is_enum(const struct btf_type *t) 344 { 345 return btf_kind(t) == BTF_KIND_ENUM; 346 } 347 348 static inline bool btf_is_fwd(const struct btf_type *t) 349 { 350 return btf_kind(t) == BTF_KIND_FWD; 351 } 352 353 static inline bool btf_is_typedef(const struct btf_type *t) 354 { 355 return btf_kind(t) == BTF_KIND_TYPEDEF; 356 } 357 358 static inline bool btf_is_volatile(const struct btf_type *t) 359 { 360 return btf_kind(t) == BTF_KIND_VOLATILE; 361 } 362 363 static inline bool btf_is_const(const struct btf_type *t) 364 { 365 return btf_kind(t) == BTF_KIND_CONST; 366 } 367 368 static inline bool btf_is_restrict(const struct btf_type *t) 369 { 370 return btf_kind(t) == BTF_KIND_RESTRICT; 371 } 372 373 static inline bool btf_is_mod(const struct btf_type *t) 374 { 375 __u16 kind = btf_kind(t); 376 377 return kind == BTF_KIND_VOLATILE || 378 kind == BTF_KIND_CONST || 379 kind == BTF_KIND_RESTRICT; 380 } 381 382 static inline bool btf_is_func(const struct btf_type *t) 383 { 384 return btf_kind(t) == BTF_KIND_FUNC; 385 } 386 387 static inline bool btf_is_func_proto(const struct btf_type *t) 388 { 389 return btf_kind(t) == BTF_KIND_FUNC_PROTO; 390 } 391 392 static inline bool btf_is_var(const struct btf_type *t) 393 { 394 return btf_kind(t) == BTF_KIND_VAR; 395 } 396 397 static inline bool btf_is_datasec(const struct btf_type *t) 398 { 399 return btf_kind(t) == BTF_KIND_DATASEC; 400 } 401 402 static inline bool btf_is_float(const struct btf_type *t) 403 { 404 return btf_kind(t) == BTF_KIND_FLOAT; 405 } 406 407 static inline bool btf_is_tag(const struct btf_type *t) 408 { 409 return btf_kind(t) == BTF_KIND_TAG; 410 } 411 412 static inline __u8 btf_int_encoding(const struct btf_type *t) 413 { 414 return BTF_INT_ENCODING(*(__u32 *)(t + 1)); 415 } 416 417 static inline __u8 btf_int_offset(const struct btf_type *t) 418 { 419 return BTF_INT_OFFSET(*(__u32 *)(t + 1)); 420 } 421 422 static inline __u8 btf_int_bits(const struct btf_type *t) 423 { 424 return BTF_INT_BITS(*(__u32 *)(t + 1)); 425 } 426 427 static inline struct btf_array *btf_array(const struct btf_type *t) 428 { 429 return (struct btf_array *)(t + 1); 430 } 431 432 static inline struct btf_enum *btf_enum(const struct btf_type *t) 433 { 434 return (struct btf_enum *)(t + 1); 435 } 436 437 static inline struct btf_member *btf_members(const struct btf_type *t) 438 { 439 return (struct btf_member *)(t + 1); 440 } 441 442 /* Get bit offset of a member with specified index. */ 443 static inline __u32 btf_member_bit_offset(const struct btf_type *t, 444 __u32 member_idx) 445 { 446 const struct btf_member *m = btf_members(t) + member_idx; 447 bool kflag = btf_kflag(t); 448 449 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset; 450 } 451 /* 452 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or 453 * BTF_KIND_UNION. If member is not a bitfield, zero is returned. 454 */ 455 static inline __u32 btf_member_bitfield_size(const struct btf_type *t, 456 __u32 member_idx) 457 { 458 const struct btf_member *m = btf_members(t) + member_idx; 459 bool kflag = btf_kflag(t); 460 461 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0; 462 } 463 464 static inline struct btf_param *btf_params(const struct btf_type *t) 465 { 466 return (struct btf_param *)(t + 1); 467 } 468 469 static inline struct btf_var *btf_var(const struct btf_type *t) 470 { 471 return (struct btf_var *)(t + 1); 472 } 473 474 static inline struct btf_var_secinfo * 475 btf_var_secinfos(const struct btf_type *t) 476 { 477 return (struct btf_var_secinfo *)(t + 1); 478 } 479 480 struct btf_tag; 481 static inline struct btf_tag *btf_tag(const struct btf_type *t) 482 { 483 return (struct btf_tag *)(t + 1); 484 } 485 486 #ifdef __cplusplus 487 } /* extern "C" */ 488 #endif 489 490 #endif /* __LIBBPF_BTF_H */ 491