btf.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/* Copyright (c) 2018 Facebook */
  3
  4#ifndef _LINUX_BTF_H
  5#define _LINUX_BTF_H 1
  6
  7#include <linux/types.h>
  8#include <linux/bpfptr.h>
  9#include <linux/bsearch.h>
 10#include <linux/btf_ids.h>
 11#include <uapi/linux/btf.h>
 12#include <uapi/linux/bpf.h>
 13
 14#define BTF_TYPE_EMIT(type) ((void)(type *)0)
 15#define BTF_TYPE_EMIT_ENUM(enum_val) ((void)enum_val)
 16
 17/* These need to be macros, as the expressions are used in assembler input */
 18#define KF_ACQUIRE	(1 << 0) /* kfunc is an acquire function */
 19#define KF_RELEASE	(1 << 1) /* kfunc is a release function */
 20#define KF_RET_NULL	(1 << 2) /* kfunc returns a pointer that may be NULL */
 21/* Trusted arguments are those which are guaranteed to be valid when passed to
 22 * the kfunc. It is used to enforce that pointers obtained from either acquire
 23 * kfuncs, or from the main kernel on a tracepoint or struct_ops callback
 24 * invocation, remain unmodified when being passed to helpers taking trusted
 25 * args.
 26 *
 27 * Consider, for example, the following new task tracepoint:
 28 *
 29 *	SEC("tp_btf/task_newtask")
 30 *	int BPF_PROG(new_task_tp, struct task_struct *task, u64 clone_flags)
 31 *	{
 32 *		...
 33 *	}
 34 *
 35 * And the following kfunc:
 36 *
 37 *	BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
 38 *
 39 * All invocations to the kfunc must pass the unmodified, unwalked task:
 40 *
 41 *	bpf_task_acquire(task);		    // Allowed
 42 *	bpf_task_acquire(task->last_wakee); // Rejected, walked task
 43 *
 44 * Programs may also pass referenced tasks directly to the kfunc:
 45 *
 46 *	struct task_struct *acquired;
 47 *
 48 *	acquired = bpf_task_acquire(task);	// Allowed, same as above
 49 *	bpf_task_acquire(acquired);		// Allowed
 50 *	bpf_task_acquire(task);			// Allowed
 51 *	bpf_task_acquire(acquired->last_wakee); // Rejected, walked task
 52 *
 53 * Programs may _not_, however, pass a task from an arbitrary fentry/fexit, or
 54 * kprobe/kretprobe to the kfunc, as BPF cannot guarantee that all of these
 55 * pointers are guaranteed to be safe. For example, the following BPF program
 56 * would be rejected:
 57 *
 58 * SEC("kretprobe/free_task")
 59 * int BPF_PROG(free_task_probe, struct task_struct *tsk)
 60 * {
 61 *	struct task_struct *acquired;
 62 *
 63 *	acquired = bpf_task_acquire(acquired); // Rejected, not a trusted pointer
 64 *	bpf_task_release(acquired);
 65 *
 66 *	return 0;
 67 * }
 68 */
 69#define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer arguments */
 70#define KF_SLEEPABLE    (1 << 5) /* kfunc may sleep */
 71#define KF_DESTRUCTIVE  (1 << 6) /* kfunc performs destructive actions */
 72#define KF_RCU          (1 << 7) /* kfunc takes either rcu or trusted pointer arguments */
 73/* only one of KF_ITER_{NEW,NEXT,DESTROY} could be specified per kfunc */
 74#define KF_ITER_NEW     (1 << 8) /* kfunc implements BPF iter constructor */
 75#define KF_ITER_NEXT    (1 << 9) /* kfunc implements BPF iter next method */
 76#define KF_ITER_DESTROY (1 << 10) /* kfunc implements BPF iter destructor */
 77#define KF_RCU_PROTECTED (1 << 11) /* kfunc should be protected by rcu cs when they are invoked */
 78#define KF_FASTCALL     (1 << 12) /* kfunc supports bpf_fastcall protocol */
 79#define KF_ARENA_RET    (1 << 13) /* kfunc returns an arena pointer */
 80#define KF_ARENA_ARG1   (1 << 14) /* kfunc takes an arena pointer as its first argument */
 81#define KF_ARENA_ARG2   (1 << 15) /* kfunc takes an arena pointer as its second argument */
 82
 83/*
 84 * Tag marking a kernel function as a kfunc. This is meant to minimize the
 85 * amount of copy-paste that kfunc authors have to include for correctness so
 86 * as to avoid issues such as the compiler inlining or eliding either a static
 87 * kfunc, or a global kfunc in an LTO build.
 88 */
 89#define __bpf_kfunc __used __retain __noclone noinline
 90
 91#define __bpf_kfunc_start_defs()					       \
 92	__diag_push();							       \
 93	__diag_ignore_all("-Wmissing-declarations",			       \
 94			  "Global kfuncs as their definitions will be in BTF");\
 95	__diag_ignore_all("-Wmissing-prototypes",			       \
 96			  "Global kfuncs as their definitions will be in BTF")
 97
 98#define __bpf_kfunc_end_defs() __diag_pop()
 99#define __bpf_hook_start() __bpf_kfunc_start_defs()
100#define __bpf_hook_end() __bpf_kfunc_end_defs()
101
102/*
103 * Return the name of the passed struct, if exists, or halt the build if for
104 * example the structure gets renamed. In this way, developers have to revisit
105 * the code using that structure name, and update it accordingly.
106 */
107#define stringify_struct(x)			\
108	({ BUILD_BUG_ON(sizeof(struct x) < 0);	\
109	   __stringify(x); })
110
111struct btf;
112struct btf_member;
113struct btf_type;
114union bpf_attr;
115struct btf_show;
116struct btf_id_set;
117struct bpf_prog;
118
119typedef int (*btf_kfunc_filter_t)(const struct bpf_prog *prog, u32 kfunc_id);
120
121struct btf_kfunc_id_set {
122	struct module *owner;
123	struct btf_id_set8 *set;
124	btf_kfunc_filter_t filter;
125};
126
127struct btf_id_dtor_kfunc {
128	u32 btf_id;
129	u32 kfunc_btf_id;
130};
131
132struct btf_struct_meta {
133	u32 btf_id;
134	struct btf_record *record;
135};
136
137struct btf_struct_metas {
138	u32 cnt;
139	struct btf_struct_meta types[];
140};
141
142extern const struct file_operations btf_fops;
143
144const char *btf_get_name(const struct btf *btf);
145void btf_get(struct btf *btf);
146void btf_put(struct btf *btf);
147const struct btf_header *btf_header(const struct btf *btf);
148int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_sz);
149struct btf *btf_get_by_fd(int fd);
150int btf_get_info_by_fd(const struct btf *btf,
151		       const union bpf_attr *attr,
152		       union bpf_attr __user *uattr);
153/* Figure out the size of a type_id.  If type_id is a modifier
154 * (e.g. const), it will be resolved to find out the type with size.
155 *
156 * For example:
157 * In describing "const void *",  type_id is "const" and "const"
158 * refers to "void *".  The return type will be "void *".
159 *
160 * If type_id is a simple "int", then return type will be "int".
161 *
162 * @btf: struct btf object
163 * @type_id: Find out the size of type_id. The type_id of the return
164 *           type is set to *type_id.
165 * @ret_size: It can be NULL.  If not NULL, the size of the return
166 *            type is set to *ret_size.
167 * Return: The btf_type (resolved to another type with size info if needed).
168 *         NULL is returned if type_id itself does not have size info
169 *         (e.g. void) or it cannot be resolved to another type that
170 *         has size info.
171 *         *type_id and *ret_size will not be changed in the
172 *         NULL return case.
173 */
174const struct btf_type *btf_type_id_size(const struct btf *btf,
175					u32 *type_id,
176					u32 *ret_size);
177
178/*
179 * Options to control show behaviour.
180 *	- BTF_SHOW_COMPACT: no formatting around type information
181 *	- BTF_SHOW_NONAME: no struct/union member names/types
182 *	- BTF_SHOW_PTR_RAW: show raw (unobfuscated) pointer values;
183 *	  equivalent to %px.
184 *	- BTF_SHOW_ZERO: show zero-valued struct/union members; they
185 *	  are not displayed by default
186 *	- BTF_SHOW_UNSAFE: skip use of bpf_probe_read() to safely read
187 *	  data before displaying it.
188 */
189#define BTF_SHOW_COMPACT	BTF_F_COMPACT
190#define BTF_SHOW_NONAME		BTF_F_NONAME
191#define BTF_SHOW_PTR_RAW	BTF_F_PTR_RAW
192#define BTF_SHOW_ZERO		BTF_F_ZERO
193#define BTF_SHOW_UNSAFE		(1ULL << 4)
194
195void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
196		       struct seq_file *m);
197int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, void *obj,
198			    struct seq_file *m, u64 flags);
199
200/*
201 * Copy len bytes of string representation of obj of BTF type_id into buf.
202 *
203 * @btf: struct btf object
204 * @type_id: type id of type obj points to
205 * @obj: pointer to typed data
206 * @buf: buffer to write to
207 * @len: maximum length to write to buf
208 * @flags: show options (see above)
209 *
210 * Return: length that would have been/was copied as per snprintf, or
211 *	   negative error.
212 */
213int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
214			   char *buf, int len, u64 flags);
215
216int btf_get_fd_by_id(u32 id);
217u32 btf_obj_id(const struct btf *btf);
218bool btf_is_kernel(const struct btf *btf);
219bool btf_is_module(const struct btf *btf);
220bool btf_is_vmlinux(const struct btf *btf);
221struct module *btf_try_get_module(const struct btf *btf);
222u32 btf_nr_types(const struct btf *btf);
223struct btf *btf_base_btf(const struct btf *btf);
224bool btf_type_is_i32(const struct btf_type *t);
225bool btf_type_is_i64(const struct btf_type *t);
226bool btf_type_is_primitive(const struct btf_type *t);
227bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
228			   const struct btf_member *m,
229			   u32 expected_offset, u32 expected_size);
230struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
231				    u32 field_mask, u32 value_size);
232int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec);
233bool btf_type_is_void(const struct btf_type *t);
234s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
235s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p);
236const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
237					       u32 id, u32 *res_id);
238const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
239					    u32 id, u32 *res_id);
240const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
241						 u32 id, u32 *res_id);
242const struct btf_type *
243btf_resolve_size(const struct btf *btf, const struct btf_type *type,
244		 u32 *type_size);
245const char *btf_type_str(const struct btf_type *t);
246
247#define for_each_member(i, struct_type, member)			\
248	for (i = 0, member = btf_type_member(struct_type);	\
249	     i < btf_type_vlen(struct_type);			\
250	     i++, member++)
251
252#define for_each_vsi(i, datasec_type, member)			\
253	for (i = 0, member = btf_type_var_secinfo(datasec_type);	\
254	     i < btf_type_vlen(datasec_type);			\
255	     i++, member++)
256
257static inline bool btf_type_is_ptr(const struct btf_type *t)
258{
259	return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
260}
261
262static inline bool btf_type_is_int(const struct btf_type *t)
263{
264	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
265}
266
267static inline bool btf_type_is_small_int(const struct btf_type *t)
268{
269	return btf_type_is_int(t) && t->size <= sizeof(u64);
270}
271
272static inline u8 btf_int_encoding(const struct btf_type *t)
273{
274	return BTF_INT_ENCODING(*(u32 *)(t + 1));
275}
276
277static inline bool btf_type_is_signed_int(const struct btf_type *t)
278{
279	return btf_type_is_int(t) && (btf_int_encoding(t) & BTF_INT_SIGNED);
280}
281
282static inline bool btf_type_is_enum(const struct btf_type *t)
283{
284	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
285}
286
287static inline bool btf_is_any_enum(const struct btf_type *t)
288{
289	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM ||
290	       BTF_INFO_KIND(t->info) == BTF_KIND_ENUM64;
291}
292
293static inline bool btf_kind_core_compat(const struct btf_type *t1,
294					const struct btf_type *t2)
295{
296	return BTF_INFO_KIND(t1->info) == BTF_INFO_KIND(t2->info) ||
297	       (btf_is_any_enum(t1) && btf_is_any_enum(t2));
298}
299
300static inline bool str_is_empty(const char *s)
301{
302	return !s || !s[0];
303}
304
305static inline u16 btf_kind(const struct btf_type *t)
306{
307	return BTF_INFO_KIND(t->info);
308}
309
310static inline bool btf_is_enum(const struct btf_type *t)
311{
312	return btf_kind(t) == BTF_KIND_ENUM;
313}
314
315static inline bool btf_is_enum64(const struct btf_type *t)
316{
317	return btf_kind(t) == BTF_KIND_ENUM64;
318}
319
320static inline u64 btf_enum64_value(const struct btf_enum64 *e)
321{
322	return ((u64)e->val_hi32 << 32) | e->val_lo32;
323}
324
325static inline bool btf_is_composite(const struct btf_type *t)
326{
327	u16 kind = btf_kind(t);
328
329	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
330}
331
332static inline bool btf_is_array(const struct btf_type *t)
333{
334	return btf_kind(t) == BTF_KIND_ARRAY;
335}
336
337static inline bool btf_is_int(const struct btf_type *t)
338{
339	return btf_kind(t) == BTF_KIND_INT;
340}
341
342static inline bool btf_is_ptr(const struct btf_type *t)
343{
344	return btf_kind(t) == BTF_KIND_PTR;
345}
346
347static inline u8 btf_int_offset(const struct btf_type *t)
348{
349	return BTF_INT_OFFSET(*(u32 *)(t + 1));
350}
351
352static inline __u8 btf_int_bits(const struct btf_type *t)
353{
354	return BTF_INT_BITS(*(__u32 *)(t + 1));
355}
356
357static inline bool btf_type_is_scalar(const struct btf_type *t)
358{
359	return btf_type_is_int(t) || btf_type_is_enum(t);
360}
361
362static inline bool btf_type_is_fwd(const struct btf_type *t)
363{
364	return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
365}
366
367static inline bool btf_type_is_typedef(const struct btf_type *t)
368{
369	return BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF;
370}
371
372static inline bool btf_type_is_volatile(const struct btf_type *t)
373{
374	return BTF_INFO_KIND(t->info) == BTF_KIND_VOLATILE;
375}
376
377static inline bool btf_type_is_func(const struct btf_type *t)
378{
379	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC;
380}
381
382static inline bool btf_type_is_func_proto(const struct btf_type *t)
383{
384	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
385}
386
387static inline bool btf_type_is_var(const struct btf_type *t)
388{
389	return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
390}
391
392static inline bool btf_type_is_type_tag(const struct btf_type *t)
393{
394	return BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG;
395}
396
397/* union is only a special case of struct:
398 * all its offsetof(member) == 0
399 */
400static inline bool btf_type_is_struct(const struct btf_type *t)
401{
402	u8 kind = BTF_INFO_KIND(t->info);
403
404	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
405}
406
407static inline bool __btf_type_is_struct(const struct btf_type *t)
408{
409	return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
410}
411
412static inline bool btf_type_is_array(const struct btf_type *t)
413{
414	return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
415}
416
417static inline u16 btf_type_vlen(const struct btf_type *t)
418{
419	return BTF_INFO_VLEN(t->info);
420}
421
422static inline u16 btf_vlen(const struct btf_type *t)
423{
424	return btf_type_vlen(t);
425}
426
427static inline u16 btf_func_linkage(const struct btf_type *t)
428{
429	return BTF_INFO_VLEN(t->info);
430}
431
432static inline bool btf_type_kflag(const struct btf_type *t)
433{
434	return BTF_INFO_KFLAG(t->info);
435}
436
437static inline u32 __btf_member_bit_offset(const struct btf_type *struct_type,
438					  const struct btf_member *member)
439{
440	return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
441					   : member->offset;
442}
443
444static inline u32 __btf_member_bitfield_size(const struct btf_type *struct_type,
445					     const struct btf_member *member)
446{
447	return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
448					   : 0;
449}
450
451static inline struct btf_member *btf_members(const struct btf_type *t)
452{
453	return (struct btf_member *)(t + 1);
454}
455
456static inline u32 btf_member_bit_offset(const struct btf_type *t, u32 member_idx)
457{
458	const struct btf_member *m = btf_members(t) + member_idx;
459
460	return __btf_member_bit_offset(t, m);
461}
462
463static inline u32 btf_member_bitfield_size(const struct btf_type *t, u32 member_idx)
464{
465	const struct btf_member *m = btf_members(t) + member_idx;
466
467	return __btf_member_bitfield_size(t, m);
468}
469
470static inline const struct btf_member *btf_type_member(const struct btf_type *t)
471{
472	return (const struct btf_member *)(t + 1);
473}
474
475static inline struct btf_array *btf_array(const struct btf_type *t)
476{
477	return (struct btf_array *)(t + 1);
478}
479
480static inline struct btf_enum *btf_enum(const struct btf_type *t)
481{
482	return (struct btf_enum *)(t + 1);
483}
484
485static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
486{
487	return (struct btf_enum64 *)(t + 1);
488}
489
490static inline const struct btf_var_secinfo *btf_type_var_secinfo(
491		const struct btf_type *t)
492{
493	return (const struct btf_var_secinfo *)(t + 1);
494}
495
496static inline struct btf_param *btf_params(const struct btf_type *t)
497{
498	return (struct btf_param *)(t + 1);
499}
500
501static inline struct btf_decl_tag *btf_decl_tag(const struct btf_type *t)
502{
503	return (struct btf_decl_tag *)(t + 1);
504}
505
506static inline int btf_id_cmp_func(const void *a, const void *b)
507{
508	const int *pa = a, *pb = b;
509
510	return *pa - *pb;
511}
512
513static inline bool btf_id_set_contains(const struct btf_id_set *set, u32 id)
514{
515	return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL;
516}
517
518static inline void *btf_id_set8_contains(const struct btf_id_set8 *set, u32 id)
519{
520	return bsearch(&id, set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func);
521}
522
523bool btf_param_match_suffix(const struct btf *btf,
524			    const struct btf_param *arg,
525			    const char *suffix);
526int btf_ctx_arg_offset(const struct btf *btf, const struct btf_type *func_proto,
527		       u32 arg_no);
528u32 btf_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, int off);
529
530struct bpf_verifier_log;
531
532#if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL)
533struct bpf_struct_ops;
534int __register_bpf_struct_ops(struct bpf_struct_ops *st_ops);
535const struct bpf_struct_ops_desc *bpf_struct_ops_find_value(struct btf *btf, u32 value_id);
536const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id);
537#else
538static inline const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id)
539{
540	return NULL;
541}
542#endif
543
544enum btf_field_iter_kind {
545	BTF_FIELD_ITER_IDS,
546	BTF_FIELD_ITER_STRS,
547};
548
549struct btf_field_desc {
550	/* once-per-type offsets */
551	int t_off_cnt, t_offs[2];
552	/* member struct size, or zero, if no members */
553	int m_sz;
554	/* repeated per-member offsets */
555	int m_off_cnt, m_offs[1];
556};
557
558struct btf_field_iter {
559	struct btf_field_desc desc;
560	void *p;
561	int m_idx;
562	int off_idx;
563	int vlen;
564};
565
566#ifdef CONFIG_BPF_SYSCALL
567const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
568void btf_set_base_btf(struct btf *btf, const struct btf *base_btf);
569int btf_relocate(struct btf *btf, const struct btf *base_btf, __u32 **map_ids);
570int btf_field_iter_init(struct btf_field_iter *it, struct btf_type *t,
571			enum btf_field_iter_kind iter_kind);
572__u32 *btf_field_iter_next(struct btf_field_iter *it);
573
574const char *btf_name_by_offset(const struct btf *btf, u32 offset);
575const char *btf_str_by_offset(const struct btf *btf, u32 offset);
576struct btf *btf_parse_vmlinux(void);
577struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog);
578u32 *btf_kfunc_id_set_contains(const struct btf *btf, u32 kfunc_btf_id,
579			       const struct bpf_prog *prog);
580u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id,
581				const struct bpf_prog *prog);
582int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
583			      const struct btf_kfunc_id_set *s);
584int register_btf_fmodret_id_set(const struct btf_kfunc_id_set *kset);
585s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id);
586int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt,
587				struct module *owner);
588struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id);
589bool btf_is_projection_of(const char *pname, const char *tname);
590bool btf_is_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
591			   const struct btf_type *t, enum bpf_prog_type prog_type,
592			   int arg);
593int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type);
594bool btf_types_are_same(const struct btf *btf1, u32 id1,
595			const struct btf *btf2, u32 id2);
596int btf_check_iter_arg(struct btf *btf, const struct btf_type *func, int arg_idx);
597
598static inline bool btf_type_is_struct_ptr(struct btf *btf, const struct btf_type *t)
599{
600	if (!btf_type_is_ptr(t))
601		return false;
602
603	t = btf_type_skip_modifiers(btf, t->type, NULL);
604
605	return btf_type_is_struct(t);
606}
607#else
608static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
609						    u32 type_id)
610{
611	return NULL;
612}
613
614static inline void btf_set_base_btf(struct btf *btf, const struct btf *base_btf)
615{
616}
617
618static inline int btf_relocate(void *log, struct btf *btf, const struct btf *base_btf,
619			       __u32 **map_ids)
620{
621	return -EOPNOTSUPP;
622}
623
624static inline int btf_field_iter_init(struct btf_field_iter *it, struct btf_type *t,
625				      enum btf_field_iter_kind iter_kind)
626{
627	return -EOPNOTSUPP;
628}
629
630static inline __u32 *btf_field_iter_next(struct btf_field_iter *it)
631{
632	return NULL;
633}
634
635static inline const char *btf_name_by_offset(const struct btf *btf,
636					     u32 offset)
637{
638	return NULL;
639}
640static inline u32 *btf_kfunc_id_set_contains(const struct btf *btf,
641					     u32 kfunc_btf_id,
642					     struct bpf_prog *prog)
643
644{
645	return NULL;
646}
647static inline int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
648					    const struct btf_kfunc_id_set *s)
649{
650	return 0;
651}
652static inline s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id)
653{
654	return -ENOENT;
655}
656static inline int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors,
657					      u32 add_cnt, struct module *owner)
658{
659	return 0;
660}
661static inline struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id)
662{
663	return NULL;
664}
665static inline bool
666btf_is_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
667		     const struct btf_type *t, enum bpf_prog_type prog_type,
668		     int arg)
669{
670	return false;
671}
672static inline int get_kern_ctx_btf_id(struct bpf_verifier_log *log,
673				      enum bpf_prog_type prog_type) {
674	return -EINVAL;
675}
676static inline bool btf_types_are_same(const struct btf *btf1, u32 id1,
677				      const struct btf *btf2, u32 id2)
678{
679	return false;
680}
681static inline int btf_check_iter_arg(struct btf *btf, const struct btf_type *func, int arg_idx)
682{
683	return -EOPNOTSUPP;
684}
685#endif
686#endif