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 BTF_BASE_ELF_SEC ".BTF.base" 22 #define MAPS_ELF_SEC ".maps" 23 24 struct btf; 25 struct btf_ext; 26 struct btf_type; 27 28 struct bpf_object; 29 30 enum btf_endianness { 31 BTF_LITTLE_ENDIAN = 0, 32 BTF_BIG_ENDIAN = 1, 33 }; 34 35 /** 36 * @brief **btf__free()** frees all data of a BTF object 37 * @param btf BTF object to free 38 */ 39 LIBBPF_API void btf__free(struct btf *btf); 40 41 /** 42 * @brief **btf__new()** creates a new instance of a BTF object from the raw 43 * bytes of an ELF's BTF section 44 * @param data raw bytes 45 * @param size number of bytes passed in `data` 46 * @return new BTF object instance which has to be eventually freed with 47 * **btf__free()** 48 * 49 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract 50 * error code from such a pointer `libbpf_get_error()` should be used. If 51 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is 52 * returned on error instead. In both cases thread-local `errno` variable is 53 * always set to error code as well. 54 */ 55 LIBBPF_API struct btf *btf__new(const void *data, __u32 size); 56 57 /** 58 * @brief **btf__new_split()** create a new instance of a BTF object from the 59 * provided raw data bytes. It takes another BTF instance, **base_btf**, which 60 * serves as a base BTF, which is extended by types in a newly created BTF 61 * instance 62 * @param data raw bytes 63 * @param size length of raw bytes 64 * @param base_btf the base BTF object 65 * @return new BTF object instance which has to be eventually freed with 66 * **btf__free()** 67 * 68 * If *base_btf* is NULL, `btf__new_split()` is equivalent to `btf__new()` and 69 * creates non-split BTF. 70 * 71 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract 72 * error code from such a pointer `libbpf_get_error()` should be used. If 73 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is 74 * returned on error instead. In both cases thread-local `errno` variable is 75 * always set to error code as well. 76 */ 77 LIBBPF_API struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf); 78 79 /** 80 * @brief **btf__new_empty()** creates an empty BTF object. Use 81 * `btf__add_*()` to populate such BTF object. 82 * @return new BTF object instance which has to be eventually freed with 83 * **btf__free()** 84 * 85 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract 86 * error code from such a pointer `libbpf_get_error()` should be used. If 87 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is 88 * returned on error instead. In both cases thread-local `errno` variable is 89 * always set to error code as well. 90 */ 91 LIBBPF_API struct btf *btf__new_empty(void); 92 93 /** 94 * @brief **btf__new_empty_split()** creates an unpopulated BTF object from an 95 * ELF BTF section except with a base BTF on top of which split BTF should be 96 * based 97 * @param base_btf base BTF object 98 * @return new BTF object instance which has to be eventually freed with 99 * **btf__free()** 100 * 101 * If *base_btf* is NULL, `btf__new_empty_split()` is equivalent to 102 * `btf__new_empty()` and creates non-split BTF. 103 * 104 * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract 105 * error code from such a pointer `libbpf_get_error()` should be used. If 106 * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is 107 * returned on error instead. In both cases thread-local `errno` variable is 108 * always set to error code as well. 109 */ 110 LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf); 111 112 /** 113 * @brief **btf__distill_base()** creates new versions of the split BTF 114 * *src_btf* and its base BTF. The new base BTF will only contain the types 115 * needed to improve robustness of the split BTF to small changes in base BTF. 116 * When that split BTF is loaded against a (possibly changed) base, this 117 * distilled base BTF will help update references to that (possibly changed) 118 * base BTF. 119 * @param src_btf source split BTF object 120 * @param new_base_btf pointer to where the new base BTF object pointer will be stored 121 * @param new_split_btf pointer to where the new split BTF object pointer will be stored 122 * @return 0 on success; negative error code, otherwise 123 * 124 * Both the new split and its associated new base BTF must be freed by 125 * the caller. 126 * 127 * If successful, 0 is returned and **new_base_btf** and **new_split_btf** 128 * will point at new base/split BTF. Both the new split and its associated 129 * new base BTF must be freed by the caller. 130 * 131 * A negative value is returned on error and the thread-local `errno` variable 132 * is set to the error code as well. 133 */ 134 LIBBPF_API int btf__distill_base(const struct btf *src_btf, struct btf **new_base_btf, 135 struct btf **new_split_btf); 136 137 LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext); 138 LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf); 139 LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext); 140 LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf); 141 LIBBPF_API struct btf *btf__parse_raw(const char *path); 142 LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf); 143 144 LIBBPF_API struct btf *btf__load_vmlinux_btf(void); 145 LIBBPF_API struct btf *btf__load_module_btf(const char *module_name, struct btf *vmlinux_btf); 146 147 LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id); 148 LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf); 149 150 LIBBPF_API int btf__load_into_kernel(struct btf *btf); 151 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, 152 const char *type_name); 153 LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf, 154 const char *type_name, __u32 kind); 155 LIBBPF_API __u32 btf__type_cnt(const struct btf *btf); 156 LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf); 157 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf, 158 __u32 id); 159 LIBBPF_API size_t btf__pointer_size(const struct btf *btf); 160 LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz); 161 LIBBPF_API enum btf_endianness btf__endianness(const struct btf *btf); 162 LIBBPF_API int btf__set_endianness(struct btf *btf, enum btf_endianness endian); 163 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id); 164 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); 165 LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id); 166 LIBBPF_API int btf__fd(const struct btf *btf); 167 LIBBPF_API void btf__set_fd(struct btf *btf, int fd); 168 LIBBPF_API const void *btf__raw_data(const struct btf *btf, __u32 *size); 169 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); 170 LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset); 171 172 LIBBPF_API struct btf_ext *btf_ext__new(const __u8 *data, __u32 size); 173 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext); 174 LIBBPF_API const void *btf_ext__raw_data(const struct btf_ext *btf_ext, __u32 *size); 175 LIBBPF_API enum btf_endianness btf_ext__endianness(const struct btf_ext *btf_ext); 176 LIBBPF_API int btf_ext__set_endianness(struct btf_ext *btf_ext, 177 enum btf_endianness endian); 178 179 LIBBPF_API int btf__find_str(struct btf *btf, const char *s); 180 LIBBPF_API int btf__add_str(struct btf *btf, const char *s); 181 LIBBPF_API int btf__add_type(struct btf *btf, const struct btf *src_btf, 182 const struct btf_type *src_type); 183 /** 184 * @brief **btf__add_btf()** appends all the BTF types from *src_btf* into *btf* 185 * @param btf BTF object which all the BTF types and strings are added to 186 * @param src_btf BTF object which all BTF types and referenced strings are copied from 187 * @return BTF type ID of the first appended BTF type, or negative error code 188 * 189 * **btf__add_btf()** can be used to simply and efficiently append the entire 190 * contents of one BTF object to another one. All the BTF type data is copied 191 * over, all referenced type IDs are adjusted by adding a necessary ID offset. 192 * Only strings referenced from BTF types are copied over and deduplicated, so 193 * if there were some unused strings in *src_btf*, those won't be copied over, 194 * which is consistent with the general string deduplication semantics of BTF 195 * writing APIs. 196 * 197 * If any error is encountered during this process, the contents of *btf* is 198 * left intact, which means that **btf__add_btf()** follows the transactional 199 * semantics and the operation as a whole is all-or-nothing. 200 * 201 * *src_btf* has to be non-split BTF, as of now copying types from split BTF 202 * is not supported and will result in -ENOTSUP error code returned. 203 */ 204 LIBBPF_API int btf__add_btf(struct btf *btf, const struct btf *src_btf); 205 206 LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding); 207 LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz); 208 LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id); 209 LIBBPF_API int btf__add_array(struct btf *btf, 210 int index_type_id, int elem_type_id, __u32 nr_elems); 211 /* struct/union construction APIs */ 212 LIBBPF_API int btf__add_struct(struct btf *btf, const char *name, __u32 sz); 213 LIBBPF_API int btf__add_union(struct btf *btf, const char *name, __u32 sz); 214 LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_id, 215 __u32 bit_offset, __u32 bit_size); 216 217 /* enum construction APIs */ 218 LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz); 219 LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value); 220 LIBBPF_API int btf__add_enum64(struct btf *btf, const char *name, __u32 bytes_sz, bool is_signed); 221 LIBBPF_API int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value); 222 223 enum btf_fwd_kind { 224 BTF_FWD_STRUCT = 0, 225 BTF_FWD_UNION = 1, 226 BTF_FWD_ENUM = 2, 227 }; 228 229 LIBBPF_API int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind); 230 LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id); 231 LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id); 232 LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id); 233 LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id); 234 LIBBPF_API int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id); 235 LIBBPF_API int btf__add_type_attr(struct btf *btf, const char *value, int ref_type_id); 236 237 /* func and func_proto construction APIs */ 238 LIBBPF_API int btf__add_func(struct btf *btf, const char *name, 239 enum btf_func_linkage linkage, int proto_type_id); 240 LIBBPF_API int btf__add_func_proto(struct btf *btf, int ret_type_id); 241 LIBBPF_API int btf__add_func_param(struct btf *btf, const char *name, int type_id); 242 243 /* var & datasec construction APIs */ 244 LIBBPF_API int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id); 245 LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz); 246 LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id, 247 __u32 offset, __u32 byte_sz); 248 249 /* tag construction API */ 250 LIBBPF_API int btf__add_decl_tag(struct btf *btf, const char *value, int ref_type_id, 251 int component_idx); 252 LIBBPF_API int btf__add_decl_attr(struct btf *btf, const char *value, int ref_type_id, 253 int component_idx); 254 255 struct btf_dedup_opts { 256 size_t sz; 257 /* optional .BTF.ext info to dedup along the main BTF info */ 258 struct btf_ext *btf_ext; 259 /* force hash collisions (used for testing) */ 260 bool force_collisions; 261 size_t :0; 262 }; 263 #define btf_dedup_opts__last_field force_collisions 264 265 LIBBPF_API int btf__dedup(struct btf *btf, const struct btf_dedup_opts *opts); 266 267 /** 268 * @brief **btf__relocate()** will check the split BTF *btf* for references 269 * to base BTF kinds, and verify those references are compatible with 270 * *base_btf*; if they are, *btf* is adjusted such that is re-parented to 271 * *base_btf* and type ids and strings are adjusted to accommodate this. 272 * @param btf split BTF object to relocate 273 * @param base_btf base BTF object 274 * @return 0 on success; negative error code, otherwise 275 * 276 * If successful, 0 is returned and **btf** now has **base_btf** as its 277 * base. 278 * 279 * A negative value is returned on error and the thread-local `errno` variable 280 * is set to the error code as well. 281 */ 282 LIBBPF_API int btf__relocate(struct btf *btf, const struct btf *base_btf); 283 284 struct btf_dump; 285 286 struct btf_dump_opts { 287 size_t sz; 288 }; 289 #define btf_dump_opts__last_field sz 290 291 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args); 292 293 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf, 294 btf_dump_printf_fn_t printf_fn, 295 void *ctx, 296 const struct btf_dump_opts *opts); 297 298 LIBBPF_API void btf_dump__free(struct btf_dump *d); 299 300 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id); 301 302 struct btf_dump_emit_type_decl_opts { 303 /* size of this struct, for forward/backward compatibility */ 304 size_t sz; 305 /* optional field name for type declaration, e.g.: 306 * - struct my_struct <FNAME> 307 * - void (*<FNAME>)(int) 308 * - char (*<FNAME>)[123] 309 */ 310 const char *field_name; 311 /* extra indentation level (in number of tabs) to emit for multi-line 312 * type declarations (e.g., anonymous struct); applies for lines 313 * starting from the second one (first line is assumed to have 314 * necessary indentation already 315 */ 316 int indent_level; 317 /* strip all the const/volatile/restrict mods */ 318 bool strip_mods; 319 size_t :0; 320 }; 321 #define btf_dump_emit_type_decl_opts__last_field strip_mods 322 323 LIBBPF_API int 324 btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, 325 const struct btf_dump_emit_type_decl_opts *opts); 326 327 328 struct btf_dump_type_data_opts { 329 /* size of this struct, for forward/backward compatibility */ 330 size_t sz; 331 const char *indent_str; 332 int indent_level; 333 /* below match "show" flags for bpf_show_snprintf() */ 334 bool compact; /* no newlines/indentation */ 335 bool skip_names; /* skip member/type names */ 336 bool emit_zeroes; /* show 0-valued fields */ 337 bool emit_strings; /* print char arrays as strings */ 338 size_t :0; 339 }; 340 #define btf_dump_type_data_opts__last_field emit_strings 341 342 LIBBPF_API int 343 btf_dump__dump_type_data(struct btf_dump *d, __u32 id, 344 const void *data, size_t data_sz, 345 const struct btf_dump_type_data_opts *opts); 346 347 /* 348 * A set of helpers for easier BTF types handling. 349 * 350 * The inline functions below rely on constants from the kernel headers which 351 * may not be available for applications including this header file. To avoid 352 * compilation errors, we define all the constants here that were added after 353 * the initial introduction of the BTF_KIND* constants. 354 */ 355 #ifndef BTF_KIND_FUNC 356 #define BTF_KIND_FUNC 12 /* Function */ 357 #define BTF_KIND_FUNC_PROTO 13 /* Function Proto */ 358 #endif 359 #ifndef BTF_KIND_VAR 360 #define BTF_KIND_VAR 14 /* Variable */ 361 #define BTF_KIND_DATASEC 15 /* Section */ 362 #endif 363 #ifndef BTF_KIND_FLOAT 364 #define BTF_KIND_FLOAT 16 /* Floating point */ 365 #endif 366 /* The kernel header switched to enums, so the following were never #defined */ 367 #define BTF_KIND_DECL_TAG 17 /* Decl Tag */ 368 #define BTF_KIND_TYPE_TAG 18 /* Type Tag */ 369 #define BTF_KIND_ENUM64 19 /* Enum for up-to 64bit values */ 370 371 static inline __u16 btf_kind(const struct btf_type *t) 372 { 373 return BTF_INFO_KIND(t->info); 374 } 375 376 static inline __u16 btf_vlen(const struct btf_type *t) 377 { 378 return BTF_INFO_VLEN(t->info); 379 } 380 381 static inline bool btf_kflag(const struct btf_type *t) 382 { 383 return BTF_INFO_KFLAG(t->info); 384 } 385 386 static inline bool btf_is_void(const struct btf_type *t) 387 { 388 return btf_kind(t) == BTF_KIND_UNKN; 389 } 390 391 static inline bool btf_is_int(const struct btf_type *t) 392 { 393 return btf_kind(t) == BTF_KIND_INT; 394 } 395 396 static inline bool btf_is_ptr(const struct btf_type *t) 397 { 398 return btf_kind(t) == BTF_KIND_PTR; 399 } 400 401 static inline bool btf_is_array(const struct btf_type *t) 402 { 403 return btf_kind(t) == BTF_KIND_ARRAY; 404 } 405 406 static inline bool btf_is_struct(const struct btf_type *t) 407 { 408 return btf_kind(t) == BTF_KIND_STRUCT; 409 } 410 411 static inline bool btf_is_union(const struct btf_type *t) 412 { 413 return btf_kind(t) == BTF_KIND_UNION; 414 } 415 416 static inline bool btf_is_composite(const struct btf_type *t) 417 { 418 __u16 kind = btf_kind(t); 419 420 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; 421 } 422 423 static inline bool btf_is_enum(const struct btf_type *t) 424 { 425 return btf_kind(t) == BTF_KIND_ENUM; 426 } 427 428 static inline bool btf_is_enum64(const struct btf_type *t) 429 { 430 return btf_kind(t) == BTF_KIND_ENUM64; 431 } 432 433 static inline bool btf_is_fwd(const struct btf_type *t) 434 { 435 return btf_kind(t) == BTF_KIND_FWD; 436 } 437 438 static inline bool btf_is_typedef(const struct btf_type *t) 439 { 440 return btf_kind(t) == BTF_KIND_TYPEDEF; 441 } 442 443 static inline bool btf_is_volatile(const struct btf_type *t) 444 { 445 return btf_kind(t) == BTF_KIND_VOLATILE; 446 } 447 448 static inline bool btf_is_const(const struct btf_type *t) 449 { 450 return btf_kind(t) == BTF_KIND_CONST; 451 } 452 453 static inline bool btf_is_restrict(const struct btf_type *t) 454 { 455 return btf_kind(t) == BTF_KIND_RESTRICT; 456 } 457 458 static inline bool btf_is_mod(const struct btf_type *t) 459 { 460 __u16 kind = btf_kind(t); 461 462 return kind == BTF_KIND_VOLATILE || 463 kind == BTF_KIND_CONST || 464 kind == BTF_KIND_RESTRICT || 465 kind == BTF_KIND_TYPE_TAG; 466 } 467 468 static inline bool btf_is_func(const struct btf_type *t) 469 { 470 return btf_kind(t) == BTF_KIND_FUNC; 471 } 472 473 static inline bool btf_is_func_proto(const struct btf_type *t) 474 { 475 return btf_kind(t) == BTF_KIND_FUNC_PROTO; 476 } 477 478 static inline bool btf_is_var(const struct btf_type *t) 479 { 480 return btf_kind(t) == BTF_KIND_VAR; 481 } 482 483 static inline bool btf_is_datasec(const struct btf_type *t) 484 { 485 return btf_kind(t) == BTF_KIND_DATASEC; 486 } 487 488 static inline bool btf_is_float(const struct btf_type *t) 489 { 490 return btf_kind(t) == BTF_KIND_FLOAT; 491 } 492 493 static inline bool btf_is_decl_tag(const struct btf_type *t) 494 { 495 return btf_kind(t) == BTF_KIND_DECL_TAG; 496 } 497 498 static inline bool btf_is_type_tag(const struct btf_type *t) 499 { 500 return btf_kind(t) == BTF_KIND_TYPE_TAG; 501 } 502 503 static inline bool btf_is_any_enum(const struct btf_type *t) 504 { 505 return btf_is_enum(t) || btf_is_enum64(t); 506 } 507 508 static inline bool btf_kind_core_compat(const struct btf_type *t1, 509 const struct btf_type *t2) 510 { 511 return btf_kind(t1) == btf_kind(t2) || 512 (btf_is_any_enum(t1) && btf_is_any_enum(t2)); 513 } 514 515 static inline __u8 btf_int_encoding(const struct btf_type *t) 516 { 517 return BTF_INT_ENCODING(*(__u32 *)(t + 1)); 518 } 519 520 static inline __u8 btf_int_offset(const struct btf_type *t) 521 { 522 return BTF_INT_OFFSET(*(__u32 *)(t + 1)); 523 } 524 525 static inline __u8 btf_int_bits(const struct btf_type *t) 526 { 527 return BTF_INT_BITS(*(__u32 *)(t + 1)); 528 } 529 530 static inline struct btf_array *btf_array(const struct btf_type *t) 531 { 532 return (struct btf_array *)(t + 1); 533 } 534 535 static inline struct btf_enum *btf_enum(const struct btf_type *t) 536 { 537 return (struct btf_enum *)(t + 1); 538 } 539 540 struct btf_enum64; 541 542 static inline struct btf_enum64 *btf_enum64(const struct btf_type *t) 543 { 544 return (struct btf_enum64 *)(t + 1); 545 } 546 547 static inline __u64 btf_enum64_value(const struct btf_enum64 *e) 548 { 549 /* struct btf_enum64 is introduced in Linux 6.0, which is very 550 * bleeding-edge. Here we are avoiding relying on struct btf_enum64 551 * definition coming from kernel UAPI headers to support wider range 552 * of system-wide kernel headers. 553 * 554 * Given this header can be also included from C++ applications, that 555 * further restricts C tricks we can use (like using compatible 556 * anonymous struct). So just treat struct btf_enum64 as 557 * a three-element array of u32 and access second (lo32) and third 558 * (hi32) elements directly. 559 * 560 * For reference, here is a struct btf_enum64 definition: 561 * 562 * const struct btf_enum64 { 563 * __u32 name_off; 564 * __u32 val_lo32; 565 * __u32 val_hi32; 566 * }; 567 */ 568 const __u32 *e64 = (const __u32 *)e; 569 570 return ((__u64)e64[2] << 32) | e64[1]; 571 } 572 573 static inline struct btf_member *btf_members(const struct btf_type *t) 574 { 575 return (struct btf_member *)(t + 1); 576 } 577 578 /* Get bit offset of a member with specified index. */ 579 static inline __u32 btf_member_bit_offset(const struct btf_type *t, 580 __u32 member_idx) 581 { 582 const struct btf_member *m = btf_members(t) + member_idx; 583 bool kflag = btf_kflag(t); 584 585 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset; 586 } 587 /* 588 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or 589 * BTF_KIND_UNION. If member is not a bitfield, zero is returned. 590 */ 591 static inline __u32 btf_member_bitfield_size(const struct btf_type *t, 592 __u32 member_idx) 593 { 594 const struct btf_member *m = btf_members(t) + member_idx; 595 bool kflag = btf_kflag(t); 596 597 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0; 598 } 599 600 static inline struct btf_param *btf_params(const struct btf_type *t) 601 { 602 return (struct btf_param *)(t + 1); 603 } 604 605 static inline struct btf_var *btf_var(const struct btf_type *t) 606 { 607 return (struct btf_var *)(t + 1); 608 } 609 610 static inline struct btf_var_secinfo * 611 btf_var_secinfos(const struct btf_type *t) 612 { 613 return (struct btf_var_secinfo *)(t + 1); 614 } 615 616 struct btf_decl_tag; 617 static inline struct btf_decl_tag *btf_decl_tag(const struct btf_type *t) 618 { 619 return (struct btf_decl_tag *)(t + 1); 620 } 621 622 #ifdef __cplusplus 623 } /* extern "C" */ 624 #endif 625 626 #endif /* __LIBBPF_BTF_H */ 627