btf.h

  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
 16extern "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
 24struct btf;
 25struct btf_ext;
 26struct btf_type;
 27
 28struct bpf_object;
 29
 30enum 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 */
 39LIBBPF_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 */
 55LIBBPF_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 */
 77LIBBPF_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 */
 91LIBBPF_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 */
110LIBBPF_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 */
134LIBBPF_API int btf__distill_base(const struct btf *src_btf, struct btf **new_base_btf,
135				 struct btf **new_split_btf);
136
137LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
138LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf);
139LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
140LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf);
141LIBBPF_API struct btf *btf__parse_raw(const char *path);
142LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf);
143
144LIBBPF_API struct btf *btf__load_vmlinux_btf(void);
145LIBBPF_API struct btf *btf__load_module_btf(const char *module_name, struct btf *vmlinux_btf);
146
147LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);
148LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);
149
150LIBBPF_API int btf__load_into_kernel(struct btf *btf);
151LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
152				   const char *type_name);
153LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
154					const char *type_name, __u32 kind);
155LIBBPF_API __u32 btf__type_cnt(const struct btf *btf);
156LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf);
157LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
158						  __u32 id);
159LIBBPF_API size_t btf__pointer_size(const struct btf *btf);
160LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz);
161LIBBPF_API enum btf_endianness btf__endianness(const struct btf *btf);
162LIBBPF_API int btf__set_endianness(struct btf *btf, enum btf_endianness endian);
163LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
164LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
165LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
166LIBBPF_API int btf__fd(const struct btf *btf);
167LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
168LIBBPF_API const void *btf__raw_data(const struct btf *btf, __u32 *size);
169LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
170LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
171
172LIBBPF_API struct btf_ext *btf_ext__new(const __u8 *data, __u32 size);
173LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
174LIBBPF_API const void *btf_ext__raw_data(const struct btf_ext *btf_ext, __u32 *size);
175LIBBPF_API enum btf_endianness btf_ext__endianness(const struct btf_ext *btf_ext);
176LIBBPF_API int btf_ext__set_endianness(struct btf_ext *btf_ext,
177				       enum btf_endianness endian);
178
179LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
180LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
181LIBBPF_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 */
204LIBBPF_API int btf__add_btf(struct btf *btf, const struct btf *src_btf);
205
206LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding);
207LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz);
208LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id);
209LIBBPF_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 */
212LIBBPF_API int btf__add_struct(struct btf *btf, const char *name, __u32 sz);
213LIBBPF_API int btf__add_union(struct btf *btf, const char *name, __u32 sz);
214LIBBPF_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 */
218LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz);
219LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value);
220LIBBPF_API int btf__add_enum64(struct btf *btf, const char *name, __u32 bytes_sz, bool is_signed);
221LIBBPF_API int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value);
222
223enum btf_fwd_kind {
224	BTF_FWD_STRUCT = 0,
225	BTF_FWD_UNION = 1,
226	BTF_FWD_ENUM = 2,
227};
228
229LIBBPF_API int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind);
230LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id);
231LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id);
232LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id);
233LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id);
234LIBBPF_API int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id);
235LIBBPF_API int btf__add_type_attr(struct btf *btf, const char *value, int ref_type_id);
236
237/* func and func_proto construction APIs */
238LIBBPF_API int btf__add_func(struct btf *btf, const char *name,
239			     enum btf_func_linkage linkage, int proto_type_id);
240LIBBPF_API int btf__add_func_proto(struct btf *btf, int ret_type_id);
241LIBBPF_API int btf__add_func_param(struct btf *btf, const char *name, int type_id);
242
243/* var & datasec construction APIs */
244LIBBPF_API int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id);
245LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz);
246LIBBPF_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 */
250LIBBPF_API int btf__add_decl_tag(struct btf *btf, const char *value, int ref_type_id,
251			    int component_idx);
252LIBBPF_API int btf__add_decl_attr(struct btf *btf, const char *value, int ref_type_id,
253				  int component_idx);
254
255struct 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
265LIBBPF_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 */
282LIBBPF_API int btf__relocate(struct btf *btf, const struct btf *base_btf);
283
284struct btf_dump;
285
286struct btf_dump_opts {
287	size_t sz;
288};
289#define btf_dump_opts__last_field sz
290
291typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
292
293LIBBPF_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
298LIBBPF_API void btf_dump__free(struct btf_dump *d);
299
300LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
301
302struct 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
323LIBBPF_API int
324btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
325			 const struct btf_dump_emit_type_decl_opts *opts);
326
327
328struct 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
342LIBBPF_API int
343btf_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
371static inline __u16 btf_kind(const struct btf_type *t)
372{
373	return BTF_INFO_KIND(t->info);
374}
375
376static inline __u16 btf_vlen(const struct btf_type *t)
377{
378	return BTF_INFO_VLEN(t->info);
379}
380
381static inline bool btf_kflag(const struct btf_type *t)
382{
383	return BTF_INFO_KFLAG(t->info);
384}
385
386static inline bool btf_is_void(const struct btf_type *t)
387{
388	return btf_kind(t) == BTF_KIND_UNKN;
389}
390
391static inline bool btf_is_int(const struct btf_type *t)
392{
393	return btf_kind(t) == BTF_KIND_INT;
394}
395
396static inline bool btf_is_ptr(const struct btf_type *t)
397{
398	return btf_kind(t) == BTF_KIND_PTR;
399}
400
401static inline bool btf_is_array(const struct btf_type *t)
402{
403	return btf_kind(t) == BTF_KIND_ARRAY;
404}
405
406static inline bool btf_is_struct(const struct btf_type *t)
407{
408	return btf_kind(t) == BTF_KIND_STRUCT;
409}
410
411static inline bool btf_is_union(const struct btf_type *t)
412{
413	return btf_kind(t) == BTF_KIND_UNION;
414}
415
416static 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
423static inline bool btf_is_enum(const struct btf_type *t)
424{
425	return btf_kind(t) == BTF_KIND_ENUM;
426}
427
428static inline bool btf_is_enum64(const struct btf_type *t)
429{
430	return btf_kind(t) == BTF_KIND_ENUM64;
431}
432
433static inline bool btf_is_fwd(const struct btf_type *t)
434{
435	return btf_kind(t) == BTF_KIND_FWD;
436}
437
438static inline bool btf_is_typedef(const struct btf_type *t)
439{
440	return btf_kind(t) == BTF_KIND_TYPEDEF;
441}
442
443static inline bool btf_is_volatile(const struct btf_type *t)
444{
445	return btf_kind(t) == BTF_KIND_VOLATILE;
446}
447
448static inline bool btf_is_const(const struct btf_type *t)
449{
450	return btf_kind(t) == BTF_KIND_CONST;
451}
452
453static inline bool btf_is_restrict(const struct btf_type *t)
454{
455	return btf_kind(t) == BTF_KIND_RESTRICT;
456}
457
458static 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
468static inline bool btf_is_func(const struct btf_type *t)
469{
470	return btf_kind(t) == BTF_KIND_FUNC;
471}
472
473static inline bool btf_is_func_proto(const struct btf_type *t)
474{
475	return btf_kind(t) == BTF_KIND_FUNC_PROTO;
476}
477
478static inline bool btf_is_var(const struct btf_type *t)
479{
480	return btf_kind(t) == BTF_KIND_VAR;
481}
482
483static inline bool btf_is_datasec(const struct btf_type *t)
484{
485	return btf_kind(t) == BTF_KIND_DATASEC;
486}
487
488static inline bool btf_is_float(const struct btf_type *t)
489{
490	return btf_kind(t) == BTF_KIND_FLOAT;
491}
492
493static inline bool btf_is_decl_tag(const struct btf_type *t)
494{
495	return btf_kind(t) == BTF_KIND_DECL_TAG;
496}
497
498static inline bool btf_is_type_tag(const struct btf_type *t)
499{
500	return btf_kind(t) == BTF_KIND_TYPE_TAG;
501}
502
503static inline bool btf_is_any_enum(const struct btf_type *t)
504{
505	return btf_is_enum(t) || btf_is_enum64(t);
506}
507
508static 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
515static inline __u8 btf_int_encoding(const struct btf_type *t)
516{
517	return BTF_INT_ENCODING(*(__u32 *)(t + 1));
518}
519
520static inline __u8 btf_int_offset(const struct btf_type *t)
521{
522	return BTF_INT_OFFSET(*(__u32 *)(t + 1));
523}
524
525static inline __u8 btf_int_bits(const struct btf_type *t)
526{
527	return BTF_INT_BITS(*(__u32 *)(t + 1));
528}
529
530static inline struct btf_array *btf_array(const struct btf_type *t)
531{
532	return (struct btf_array *)(t + 1);
533}
534
535static inline struct btf_enum *btf_enum(const struct btf_type *t)
536{
537	return (struct btf_enum *)(t + 1);
538}
539
540struct btf_enum64;
541
542static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
543{
544	return (struct btf_enum64 *)(t + 1);
545}
546
547static 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
573static 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. */
579static 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 */
591static 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
600static inline struct btf_param *btf_params(const struct btf_type *t)
601{
602	return (struct btf_param *)(t + 1);
603}
604
605static inline struct btf_var *btf_var(const struct btf_type *t)
606{
607	return (struct btf_var *)(t + 1);
608}
609
610static inline struct btf_var_secinfo *
611btf_var_secinfos(const struct btf_type *t)
612{
613	return (struct btf_var_secinfo *)(t + 1);
614}
615
616struct btf_decl_tag;
617static 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 */