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_permute_opts { 285 size_t sz; 286 /* optional .BTF.ext info along the main BTF info */ 287 struct btf_ext *btf_ext; 288 size_t :0; 289 }; 290 #define btf_permute_opts__last_field btf_ext 291 292 /** 293 * @brief **btf__permute()** rearranges BTF types in-place according to a specified ID mapping 294 * @param btf BTF object to permute 295 * @param id_map Array mapping original type IDs to new IDs 296 * @param id_map_cnt Number of elements in @id_map 297 * @param opts Optional parameters, including BTF extension data for reference updates 298 * @return 0 on success, negative error code on failure 299 * 300 * **btf__permute()** reorders BTF types based on the provided @id_map array, 301 * updating all internal type references to maintain consistency. The function 302 * operates in-place, modifying the BTF object directly. 303 * 304 * For **base BTF**: 305 * - @id_map must include all types from ID 0 to `btf__type_cnt(btf) - 1` 306 * - @id_map_cnt must be `btf__type_cnt(btf)` 307 * - Mapping is defined as `id_map[original_id] = new_id` 308 * - `id_map[0]` must be 0 (void type cannot be moved) 309 * 310 * For **split BTF**: 311 * - @id_map must include only split types (types added on top of the base BTF) 312 * - @id_map_cnt must be `btf__type_cnt(btf) - btf__type_cnt(btf__base_btf(btf))` 313 * - Mapping is defined as `id_map[original_id - start_id] = new_id` 314 * - `start_id` equals `btf__type_cnt(btf__base_btf(btf))` 315 * 316 * After permutation, all type references within the BTF data and optional 317 * BTF extension (if provided via @opts) are updated automatically. 318 * 319 * On error, returns a negative error code and sets errno: 320 * - `-EINVAL`: Invalid parameters or invalid ID mapping 321 * - `-ENOMEM`: Memory allocation failure 322 */ 323 LIBBPF_API int btf__permute(struct btf *btf, __u32 *id_map, __u32 id_map_cnt, 324 const struct btf_permute_opts *opts); 325 326 struct btf_dump; 327 328 struct btf_dump_opts { 329 size_t sz; 330 }; 331 #define btf_dump_opts__last_field sz 332 333 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args); 334 335 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf, 336 btf_dump_printf_fn_t printf_fn, 337 void *ctx, 338 const struct btf_dump_opts *opts); 339 340 LIBBPF_API void btf_dump__free(struct btf_dump *d); 341 342 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id); 343 344 struct btf_dump_emit_type_decl_opts { 345 /* size of this struct, for forward/backward compatibility */ 346 size_t sz; 347 /* optional field name for type declaration, e.g.: 348 * - struct my_struct <FNAME> 349 * - void (*<FNAME>)(int) 350 * - char (*<FNAME>)[123] 351 */ 352 const char *field_name; 353 /* extra indentation level (in number of tabs) to emit for multi-line 354 * type declarations (e.g., anonymous struct); applies for lines 355 * starting from the second one (first line is assumed to have 356 * necessary indentation already 357 */ 358 int indent_level; 359 /* strip all the const/volatile/restrict mods */ 360 bool strip_mods; 361 size_t :0; 362 }; 363 #define btf_dump_emit_type_decl_opts__last_field strip_mods 364 365 LIBBPF_API int 366 btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, 367 const struct btf_dump_emit_type_decl_opts *opts); 368 369 370 struct btf_dump_type_data_opts { 371 /* size of this struct, for forward/backward compatibility */ 372 size_t sz; 373 const char *indent_str; 374 int indent_level; 375 /* below match "show" flags for bpf_show_snprintf() */ 376 bool compact; /* no newlines/indentation */ 377 bool skip_names; /* skip member/type names */ 378 bool emit_zeroes; /* show 0-valued fields */ 379 bool emit_strings; /* print char arrays as strings */ 380 size_t :0; 381 }; 382 #define btf_dump_type_data_opts__last_field emit_strings 383 384 LIBBPF_API int 385 btf_dump__dump_type_data(struct btf_dump *d, __u32 id, 386 const void *data, size_t data_sz, 387 const struct btf_dump_type_data_opts *opts); 388 389 /* 390 * A set of helpers for easier BTF types handling. 391 * 392 * The inline functions below rely on constants from the kernel headers which 393 * may not be available for applications including this header file. To avoid 394 * compilation errors, we define all the constants here that were added after 395 * the initial introduction of the BTF_KIND* constants. 396 */ 397 #ifndef BTF_KIND_FUNC 398 #define BTF_KIND_FUNC 12 /* Function */ 399 #define BTF_KIND_FUNC_PROTO 13 /* Function Proto */ 400 #endif 401 #ifndef BTF_KIND_VAR 402 #define BTF_KIND_VAR 14 /* Variable */ 403 #define BTF_KIND_DATASEC 15 /* Section */ 404 #endif 405 #ifndef BTF_KIND_FLOAT 406 #define BTF_KIND_FLOAT 16 /* Floating point */ 407 #endif 408 /* The kernel header switched to enums, so the following were never #defined */ 409 #define BTF_KIND_DECL_TAG 17 /* Decl Tag */ 410 #define BTF_KIND_TYPE_TAG 18 /* Type Tag */ 411 #define BTF_KIND_ENUM64 19 /* Enum for up-to 64bit values */ 412 413 static inline __u16 btf_kind(const struct btf_type *t) 414 { 415 return BTF_INFO_KIND(t->info); 416 } 417 418 static inline __u16 btf_vlen(const struct btf_type *t) 419 { 420 return BTF_INFO_VLEN(t->info); 421 } 422 423 static inline bool btf_kflag(const struct btf_type *t) 424 { 425 return BTF_INFO_KFLAG(t->info); 426 } 427 428 static inline bool btf_is_void(const struct btf_type *t) 429 { 430 return btf_kind(t) == BTF_KIND_UNKN; 431 } 432 433 static inline bool btf_is_int(const struct btf_type *t) 434 { 435 return btf_kind(t) == BTF_KIND_INT; 436 } 437 438 static inline bool btf_is_ptr(const struct btf_type *t) 439 { 440 return btf_kind(t) == BTF_KIND_PTR; 441 } 442 443 static inline bool btf_is_array(const struct btf_type *t) 444 { 445 return btf_kind(t) == BTF_KIND_ARRAY; 446 } 447 448 static inline bool btf_is_struct(const struct btf_type *t) 449 { 450 return btf_kind(t) == BTF_KIND_STRUCT; 451 } 452 453 static inline bool btf_is_union(const struct btf_type *t) 454 { 455 return btf_kind(t) == BTF_KIND_UNION; 456 } 457 458 static inline bool btf_is_composite(const struct btf_type *t) 459 { 460 __u16 kind = btf_kind(t); 461 462 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; 463 } 464 465 static inline bool btf_is_enum(const struct btf_type *t) 466 { 467 return btf_kind(t) == BTF_KIND_ENUM; 468 } 469 470 static inline bool btf_is_enum64(const struct btf_type *t) 471 { 472 return btf_kind(t) == BTF_KIND_ENUM64; 473 } 474 475 static inline bool btf_is_fwd(const struct btf_type *t) 476 { 477 return btf_kind(t) == BTF_KIND_FWD; 478 } 479 480 static inline bool btf_is_typedef(const struct btf_type *t) 481 { 482 return btf_kind(t) == BTF_KIND_TYPEDEF; 483 } 484 485 static inline bool btf_is_volatile(const struct btf_type *t) 486 { 487 return btf_kind(t) == BTF_KIND_VOLATILE; 488 } 489 490 static inline bool btf_is_const(const struct btf_type *t) 491 { 492 return btf_kind(t) == BTF_KIND_CONST; 493 } 494 495 static inline bool btf_is_restrict(const struct btf_type *t) 496 { 497 return btf_kind(t) == BTF_KIND_RESTRICT; 498 } 499 500 static inline bool btf_is_mod(const struct btf_type *t) 501 { 502 __u16 kind = btf_kind(t); 503 504 return kind == BTF_KIND_VOLATILE || 505 kind == BTF_KIND_CONST || 506 kind == BTF_KIND_RESTRICT || 507 kind == BTF_KIND_TYPE_TAG; 508 } 509 510 static inline bool btf_is_func(const struct btf_type *t) 511 { 512 return btf_kind(t) == BTF_KIND_FUNC; 513 } 514 515 static inline bool btf_is_func_proto(const struct btf_type *t) 516 { 517 return btf_kind(t) == BTF_KIND_FUNC_PROTO; 518 } 519 520 static inline bool btf_is_var(const struct btf_type *t) 521 { 522 return btf_kind(t) == BTF_KIND_VAR; 523 } 524 525 static inline bool btf_is_datasec(const struct btf_type *t) 526 { 527 return btf_kind(t) == BTF_KIND_DATASEC; 528 } 529 530 static inline bool btf_is_float(const struct btf_type *t) 531 { 532 return btf_kind(t) == BTF_KIND_FLOAT; 533 } 534 535 static inline bool btf_is_decl_tag(const struct btf_type *t) 536 { 537 return btf_kind(t) == BTF_KIND_DECL_TAG; 538 } 539 540 static inline bool btf_is_type_tag(const struct btf_type *t) 541 { 542 return btf_kind(t) == BTF_KIND_TYPE_TAG; 543 } 544 545 static inline bool btf_is_any_enum(const struct btf_type *t) 546 { 547 return btf_is_enum(t) || btf_is_enum64(t); 548 } 549 550 static inline bool btf_kind_core_compat(const struct btf_type *t1, 551 const struct btf_type *t2) 552 { 553 return btf_kind(t1) == btf_kind(t2) || 554 (btf_is_any_enum(t1) && btf_is_any_enum(t2)); 555 } 556 557 static inline __u8 btf_int_encoding(const struct btf_type *t) 558 { 559 return BTF_INT_ENCODING(*(__u32 *)(t + 1)); 560 } 561 562 static inline __u8 btf_int_offset(const struct btf_type *t) 563 { 564 return BTF_INT_OFFSET(*(__u32 *)(t + 1)); 565 } 566 567 static inline __u8 btf_int_bits(const struct btf_type *t) 568 { 569 return BTF_INT_BITS(*(__u32 *)(t + 1)); 570 } 571 572 static inline struct btf_array *btf_array(const struct btf_type *t) 573 { 574 return (struct btf_array *)(t + 1); 575 } 576 577 static inline struct btf_enum *btf_enum(const struct btf_type *t) 578 { 579 return (struct btf_enum *)(t + 1); 580 } 581 582 struct btf_enum64; 583 584 static inline struct btf_enum64 *btf_enum64(const struct btf_type *t) 585 { 586 return (struct btf_enum64 *)(t + 1); 587 } 588 589 static inline __u64 btf_enum64_value(const struct btf_enum64 *e) 590 { 591 /* struct btf_enum64 is introduced in Linux 6.0, which is very 592 * bleeding-edge. Here we are avoiding relying on struct btf_enum64 593 * definition coming from kernel UAPI headers to support wider range 594 * of system-wide kernel headers. 595 * 596 * Given this header can be also included from C++ applications, that 597 * further restricts C tricks we can use (like using compatible 598 * anonymous struct). So just treat struct btf_enum64 as 599 * a three-element array of u32 and access second (lo32) and third 600 * (hi32) elements directly. 601 * 602 * For reference, here is a struct btf_enum64 definition: 603 * 604 * const struct btf_enum64 { 605 * __u32 name_off; 606 * __u32 val_lo32; 607 * __u32 val_hi32; 608 * }; 609 */ 610 const __u32 *e64 = (const __u32 *)e; 611 612 return ((__u64)e64[2] << 32) | e64[1]; 613 } 614 615 static inline struct btf_member *btf_members(const struct btf_type *t) 616 { 617 return (struct btf_member *)(t + 1); 618 } 619 620 /* Get bit offset of a member with specified index. */ 621 static inline __u32 btf_member_bit_offset(const struct btf_type *t, 622 __u32 member_idx) 623 { 624 const struct btf_member *m = btf_members(t) + member_idx; 625 bool kflag = btf_kflag(t); 626 627 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset; 628 } 629 /* 630 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or 631 * BTF_KIND_UNION. If member is not a bitfield, zero is returned. 632 */ 633 static inline __u32 btf_member_bitfield_size(const struct btf_type *t, 634 __u32 member_idx) 635 { 636 const struct btf_member *m = btf_members(t) + member_idx; 637 bool kflag = btf_kflag(t); 638 639 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0; 640 } 641 642 static inline struct btf_param *btf_params(const struct btf_type *t) 643 { 644 return (struct btf_param *)(t + 1); 645 } 646 647 static inline struct btf_var *btf_var(const struct btf_type *t) 648 { 649 return (struct btf_var *)(t + 1); 650 } 651 652 static inline struct btf_var_secinfo * 653 btf_var_secinfos(const struct btf_type *t) 654 { 655 return (struct btf_var_secinfo *)(t + 1); 656 } 657 658 struct btf_decl_tag; 659 static inline struct btf_decl_tag *btf_decl_tag(const struct btf_type *t) 660 { 661 return (struct btf_decl_tag *)(t + 1); 662 } 663 664 #ifdef __cplusplus 665 } /* extern "C" */ 666 #endif 667 668 #endif /* __LIBBPF_BTF_H */ 669