1 /* SPDX-License-Identifier: GPL-2.0 */ 1
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)en
16
17 /* These need to be macros, as the expressions
18 #define KF_ACQUIRE (1 << 0) /* kfunc is a
19 #define KF_RELEASE (1 << 1) /* kfunc is a
20 #define KF_RET_NULL (1 << 2) /* kfunc retu
21 /* Trusted arguments are those which are guara
22 * the kfunc. It is used to enforce that point
23 * kfuncs, or from the main kernel on a tracep
24 * invocation, remain unmodified when being pa
25 * args.
26 *
27 * Consider, for example, the following new ta
28 *
29 * SEC("tp_btf/task_newtask")
30 * int BPF_PROG(new_task_tp, struct task_
31 * {
32 * ...
33 * }
34 *
35 * And the following kfunc:
36 *
37 * BTF_ID_FLAGS(func, bpf_task_acquire, K
38 *
39 * All invocations to the kfunc must pass the
40 *
41 * bpf_task_acquire(task); //
42 * bpf_task_acquire(task->last_wakee); //
43 *
44 * Programs may also pass referenced tasks dir
45 *
46 * struct task_struct *acquired;
47 *
48 * acquired = bpf_task_acquire(task);
49 * bpf_task_acquire(acquired);
50 * bpf_task_acquire(task);
51 * bpf_task_acquire(acquired->last_wakee)
52 *
53 * Programs may _not_, however, pass a task fr
54 * kprobe/kretprobe to the kfunc, as BPF canno
55 * pointers are guaranteed to be safe. For exa
56 * would be rejected:
57 *
58 * SEC("kretprobe/free_task")
59 * int BPF_PROG(free_task_probe, struct task_s
60 * {
61 * struct task_struct *acquired;
62 *
63 * acquired = bpf_task_acquire(acquired);
64 * bpf_task_release(acquired);
65 *
66 * return 0;
67 * }
68 */
69 #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only
70 #define KF_SLEEPABLE (1 << 5) /* kfunc may
71 #define KF_DESTRUCTIVE (1 << 6) /* kfunc perf
72 #define KF_RCU (1 << 7) /* kfunc take
73 /* only one of KF_ITER_{NEW,NEXT,DESTROY} coul
74 #define KF_ITER_NEW (1 << 8) /* kfunc impl
75 #define KF_ITER_NEXT (1 << 9) /* kfunc impl
76 #define KF_ITER_DESTROY (1 << 10) /* kfunc imp
77 #define KF_RCU_PROTECTED (1 << 11) /* kfunc sh
78
79 /*
80 * Tag marking a kernel function as a kfunc. T
81 * amount of copy-paste that kfunc authors hav
82 * as to avoid issues such as the compiler inl
83 * kfunc, or a global kfunc in an LTO build.
84 */
85 #define __bpf_kfunc __used __retain noinline
86
87 #define __bpf_kfunc_start_defs()
88 __diag_push();
89 __diag_ignore_all("-Wmissing-declarati
90 "Global kfuncs as th
91 __diag_ignore_all("-Wmissing-prototype
92 "Global kfuncs as th
93
94 #define __bpf_kfunc_end_defs() __diag_pop()
95 #define __bpf_hook_start() __bpf_kfunc_start_d
96 #define __bpf_hook_end() __bpf_kfunc_end_defs(
97
98 /*
99 * Return the name of the passed struct, if ex
100 * example the structure gets renamed. In this
101 * the code using that structure name, and upd
102 */
103 #define stringify_struct(x)
104 ({ BUILD_BUG_ON(sizeof(struct x) < 0);
105 __stringify(x); })
106
107 struct btf;
108 struct btf_member;
109 struct btf_type;
110 union bpf_attr;
111 struct btf_show;
112 struct btf_id_set;
113 struct bpf_prog;
114
115 typedef int (*btf_kfunc_filter_t)(const struct
116
117 struct btf_kfunc_id_set {
118 struct module *owner;
119 struct btf_id_set8 *set;
120 btf_kfunc_filter_t filter;
121 };
122
123 struct btf_id_dtor_kfunc {
124 u32 btf_id;
125 u32 kfunc_btf_id;
126 };
127
128 struct btf_struct_meta {
129 u32 btf_id;
130 struct btf_record *record;
131 };
132
133 struct btf_struct_metas {
134 u32 cnt;
135 struct btf_struct_meta types[];
136 };
137
138 extern const struct file_operations btf_fops;
139
140 const char *btf_get_name(const struct btf *btf
141 void btf_get(struct btf *btf);
142 void btf_put(struct btf *btf);
143 const struct btf_header *btf_header(const stru
144 int btf_new_fd(const union bpf_attr *attr, bpf
145 struct btf *btf_get_by_fd(int fd);
146 int btf_get_info_by_fd(const struct btf *btf,
147 const union bpf_attr *a
148 union bpf_attr __user *
149 /* Figure out the size of a type_id. If type_
150 * (e.g. const), it will be resolved to find o
151 *
152 * For example:
153 * In describing "const void *", type_id is "
154 * refers to "void *". The return type will b
155 *
156 * If type_id is a simple "int", then return t
157 *
158 * @btf: struct btf object
159 * @type_id: Find out the size of type_id. The
160 * type is set to *type_id.
161 * @ret_size: It can be NULL. If not NULL, th
162 * type is set to *ret_size.
163 * Return: The btf_type (resolved to another t
164 * NULL is returned if type_id itself
165 * (e.g. void) or it cannot be resolve
166 * has size info.
167 * *type_id and *ret_size will not be
168 * NULL return case.
169 */
170 const struct btf_type *btf_type_id_size(const
171 u32 *t
172 u32 *r
173
174 /*
175 * Options to control show behaviour.
176 * - BTF_SHOW_COMPACT: no formatting arou
177 * - BTF_SHOW_NONAME: no struct/union mem
178 * - BTF_SHOW_PTR_RAW: show raw (unobfusc
179 * equivalent to %px.
180 * - BTF_SHOW_ZERO: show zero-valued stru
181 * are not displayed by default
182 * - BTF_SHOW_UNSAFE: skip use of bpf_pro
183 * data before displaying it.
184 */
185 #define BTF_SHOW_COMPACT BTF_F_COMPACT
186 #define BTF_SHOW_NONAME BTF_F_NONAME
187 #define BTF_SHOW_PTR_RAW BTF_F_PTR_RAW
188 #define BTF_SHOW_ZERO BTF_F_ZERO
189 #define BTF_SHOW_UNSAFE (1ULL << 4)
190
191 void btf_type_seq_show(const struct btf *btf,
192 struct seq_file *m);
193 int btf_type_seq_show_flags(const struct btf *
194 struct seq_file *m
195
196 /*
197 * Copy len bytes of string representation of
198 *
199 * @btf: struct btf object
200 * @type_id: type id of type obj points to
201 * @obj: pointer to typed data
202 * @buf: buffer to write to
203 * @len: maximum length to write to buf
204 * @flags: show options (see above)
205 *
206 * Return: length that would have been/was cop
207 * negative error.
208 */
209 int btf_type_snprintf_show(const struct btf *b
210 char *buf, int len,
211
212 int btf_get_fd_by_id(u32 id);
213 u32 btf_obj_id(const struct btf *btf);
214 bool btf_is_kernel(const struct btf *btf);
215 bool btf_is_module(const struct btf *btf);
216 bool btf_is_vmlinux(const struct btf *btf);
217 struct module *btf_try_get_module(const struct
218 u32 btf_nr_types(const struct btf *btf);
219 struct btf *btf_base_btf(const struct btf *btf
220 bool btf_member_is_reg_int(const struct btf *b
221 const struct btf_me
222 u32 expected_offset
223 struct btf_record *btf_parse_fields(const stru
224 u32 field_
225 int btf_check_and_fixup_fields(const struct bt
226 bool btf_type_is_void(const struct btf_type *t
227 s32 btf_find_by_name_kind(const struct btf *bt
228 s32 bpf_find_btf_id(const char *name, u32 kind
229 const struct btf_type *btf_type_skip_modifiers
230
231 const struct btf_type *btf_type_resolve_ptr(co
232 u3
233 const struct btf_type *btf_type_resolve_func_p
234
235 const struct btf_type *
236 btf_resolve_size(const struct btf *btf, const
237 u32 *type_size);
238 const char *btf_type_str(const struct btf_type
239
240 #define for_each_member(i, struct_type, member
241 for (i = 0, member = btf_type_member(s
242 i < btf_type_vlen(struct_type);
243 i++, member++)
244
245 #define for_each_vsi(i, datasec_type, member)
246 for (i = 0, member = btf_type_var_seci
247 i < btf_type_vlen(datasec_type);
248 i++, member++)
249
250 static inline bool btf_type_is_ptr(const struc
251 {
252 return BTF_INFO_KIND(t->info) == BTF_K
253 }
254
255 static inline bool btf_type_is_int(const struc
256 {
257 return BTF_INFO_KIND(t->info) == BTF_K
258 }
259
260 static inline bool btf_type_is_small_int(const
261 {
262 return btf_type_is_int(t) && t->size <
263 }
264
265 static inline u8 btf_int_encoding(const struct
266 {
267 return BTF_INT_ENCODING(*(u32 *)(t + 1
268 }
269
270 static inline bool btf_type_is_signed_int(cons
271 {
272 return btf_type_is_int(t) && (btf_int_
273 }
274
275 static inline bool btf_type_is_enum(const stru
276 {
277 return BTF_INFO_KIND(t->info) == BTF_K
278 }
279
280 static inline bool btf_is_any_enum(const struc
281 {
282 return BTF_INFO_KIND(t->info) == BTF_K
283 BTF_INFO_KIND(t->info) == BTF_K
284 }
285
286 static inline bool btf_kind_core_compat(const
287 const
288 {
289 return BTF_INFO_KIND(t1->info) == BTF_
290 (btf_is_any_enum(t1) && btf_is_
291 }
292
293 static inline bool str_is_empty(const char *s)
294 {
295 return !s || !s[0];
296 }
297
298 static inline u16 btf_kind(const struct btf_ty
299 {
300 return BTF_INFO_KIND(t->info);
301 }
302
303 static inline bool btf_is_enum(const struct bt
304 {
305 return btf_kind(t) == BTF_KIND_ENUM;
306 }
307
308 static inline bool btf_is_enum64(const struct
309 {
310 return btf_kind(t) == BTF_KIND_ENUM64;
311 }
312
313 static inline u64 btf_enum64_value(const struc
314 {
315 return ((u64)e->val_hi32 << 32) | e->v
316 }
317
318 static inline bool btf_is_composite(const stru
319 {
320 u16 kind = btf_kind(t);
321
322 return kind == BTF_KIND_STRUCT || kind
323 }
324
325 static inline bool btf_is_array(const struct b
326 {
327 return btf_kind(t) == BTF_KIND_ARRAY;
328 }
329
330 static inline bool btf_is_int(const struct btf
331 {
332 return btf_kind(t) == BTF_KIND_INT;
333 }
334
335 static inline bool btf_is_ptr(const struct btf
336 {
337 return btf_kind(t) == BTF_KIND_PTR;
338 }
339
340 static inline u8 btf_int_offset(const struct b
341 {
342 return BTF_INT_OFFSET(*(u32 *)(t + 1))
343 }
344
345 static inline __u8 btf_int_bits(const struct b
346 {
347 return BTF_INT_BITS(*(__u32 *)(t + 1))
348 }
349
350 static inline bool btf_type_is_scalar(const st
351 {
352 return btf_type_is_int(t) || btf_type_
353 }
354
355 static inline bool btf_type_is_typedef(const s
356 {
357 return BTF_INFO_KIND(t->info) == BTF_K
358 }
359
360 static inline bool btf_type_is_volatile(const
361 {
362 return BTF_INFO_KIND(t->info) == BTF_K
363 }
364
365 static inline bool btf_type_is_func(const stru
366 {
367 return BTF_INFO_KIND(t->info) == BTF_K
368 }
369
370 static inline bool btf_type_is_func_proto(cons
371 {
372 return BTF_INFO_KIND(t->info) == BTF_K
373 }
374
375 static inline bool btf_type_is_var(const struc
376 {
377 return BTF_INFO_KIND(t->info) == BTF_K
378 }
379
380 static inline bool btf_type_is_type_tag(const
381 {
382 return BTF_INFO_KIND(t->info) == BTF_K
383 }
384
385 /* union is only a special case of struct:
386 * all its offsetof(member) == 0
387 */
388 static inline bool btf_type_is_struct(const st
389 {
390 u8 kind = BTF_INFO_KIND(t->info);
391
392 return kind == BTF_KIND_STRUCT || kind
393 }
394
395 static inline bool __btf_type_is_struct(const
396 {
397 return BTF_INFO_KIND(t->info) == BTF_K
398 }
399
400 static inline bool btf_type_is_array(const str
401 {
402 return BTF_INFO_KIND(t->info) == BTF_K
403 }
404
405 static inline u16 btf_type_vlen(const struct b
406 {
407 return BTF_INFO_VLEN(t->info);
408 }
409
410 static inline u16 btf_vlen(const struct btf_ty
411 {
412 return btf_type_vlen(t);
413 }
414
415 static inline u16 btf_func_linkage(const struc
416 {
417 return BTF_INFO_VLEN(t->info);
418 }
419
420 static inline bool btf_type_kflag(const struct
421 {
422 return BTF_INFO_KFLAG(t->info);
423 }
424
425 static inline u32 __btf_member_bit_offset(cons
426 cons
427 {
428 return btf_type_kflag(struct_type) ? B
429 : m
430 }
431
432 static inline u32 __btf_member_bitfield_size(c
433 c
434 {
435 return btf_type_kflag(struct_type) ? B
436 : 0
437 }
438
439 static inline struct btf_member *btf_members(c
440 {
441 return (struct btf_member *)(t + 1);
442 }
443
444 static inline u32 btf_member_bit_offset(const
445 {
446 const struct btf_member *m = btf_membe
447
448 return __btf_member_bit_offset(t, m);
449 }
450
451 static inline u32 btf_member_bitfield_size(con
452 {
453 const struct btf_member *m = btf_membe
454
455 return __btf_member_bitfield_size(t, m
456 }
457
458 static inline const struct btf_member *btf_typ
459 {
460 return (const struct btf_member *)(t +
461 }
462
463 static inline struct btf_array *btf_array(cons
464 {
465 return (struct btf_array *)(t + 1);
466 }
467
468 static inline struct btf_enum *btf_enum(const
469 {
470 return (struct btf_enum *)(t + 1);
471 }
472
473 static inline struct btf_enum64 *btf_enum64(co
474 {
475 return (struct btf_enum64 *)(t + 1);
476 }
477
478 static inline const struct btf_var_secinfo *bt
479 const struct btf_type *t)
480 {
481 return (const struct btf_var_secinfo *
482 }
483
484 static inline struct btf_param *btf_params(con
485 {
486 return (struct btf_param *)(t + 1);
487 }
488
489 static inline struct btf_decl_tag *btf_decl_ta
490 {
491 return (struct btf_decl_tag *)(t + 1);
492 }
493
494 static inline int btf_id_cmp_func(const void *
495 {
496 const int *pa = a, *pb = b;
497
498 return *pa - *pb;
499 }
500
501 static inline bool btf_id_set_contains(const s
502 {
503 return bsearch(&id, set->ids, set->cnt
504 }
505
506 static inline void *btf_id_set8_contains(const
507 {
508 return bsearch(&id, set->pairs, set->c
509 }
510
511 bool btf_param_match_suffix(const struct btf *
512 const struct btf_p
513 const char *suffix
514 int btf_ctx_arg_offset(const struct btf *btf,
515 u32 arg_no);
516
517 struct bpf_verifier_log;
518
519 #if defined(CONFIG_BPF_JIT) && defined(CONFIG_
520 struct bpf_struct_ops;
521 int __register_bpf_struct_ops(struct bpf_struc
522 const struct bpf_struct_ops_desc *bpf_struct_o
523 const struct bpf_struct_ops_desc *bpf_struct_o
524 #else
525 static inline const struct bpf_struct_ops_desc
526 {
527 return NULL;
528 }
529 #endif
530
531 enum btf_field_iter_kind {
532 BTF_FIELD_ITER_IDS,
533 BTF_FIELD_ITER_STRS,
534 };
535
536 struct btf_field_desc {
537 /* once-per-type offsets */
538 int t_off_cnt, t_offs[2];
539 /* member struct size, or zero, if no
540 int m_sz;
541 /* repeated per-member offsets */
542 int m_off_cnt, m_offs[1];
543 };
544
545 struct btf_field_iter {
546 struct btf_field_desc desc;
547 void *p;
548 int m_idx;
549 int off_idx;
550 int vlen;
551 };
552
553 #ifdef CONFIG_BPF_SYSCALL
554 const struct btf_type *btf_type_by_id(const st
555 void btf_set_base_btf(struct btf *btf, const s
556 int btf_relocate(struct btf *btf, const struct
557 int btf_field_iter_init(struct btf_field_iter
558 enum btf_field_iter_ki
559 __u32 *btf_field_iter_next(struct btf_field_it
560
561 const char *btf_name_by_offset(const struct bt
562 const char *btf_str_by_offset(const struct btf
563 struct btf *btf_parse_vmlinux(void);
564 struct btf *bpf_prog_get_target_btf(const stru
565 u32 *btf_kfunc_id_set_contains(const struct bt
566 const struct bp
567 u32 *btf_kfunc_is_modify_return(const struct b
568 const struct b
569 int register_btf_kfunc_id_set(enum bpf_prog_ty
570 const struct btf
571 int register_btf_fmodret_id_set(const struct b
572 s32 btf_find_dtor_kfunc(struct btf *btf, u32 b
573 int register_btf_id_dtor_kfuncs(const struct b
574 struct module
575 struct btf_struct_meta *btf_find_struct_meta(c
576 bool btf_is_projection_of(const char *pname, c
577 bool btf_is_prog_ctx_type(struct bpf_verifier_
578 const struct btf_ty
579 int arg);
580 int get_kern_ctx_btf_id(struct bpf_verifier_lo
581 bool btf_types_are_same(const struct btf *btf1
582 const struct btf *btf2
583 int btf_check_iter_arg(struct btf *btf, const
584 #else
585 static inline const struct btf_type *btf_type_
586
587 {
588 return NULL;
589 }
590
591 static inline void btf_set_base_btf(struct btf
592 {
593 }
594
595 static inline int btf_relocate(void *log, stru
596 __u32 **map_ids
597 {
598 return -EOPNOTSUPP;
599 }
600
601 static inline int btf_field_iter_init(struct b
602 enum btf
603 {
604 return -EOPNOTSUPP;
605 }
606
607 static inline __u32 *btf_field_iter_next(struc
608 {
609 return NULL;
610 }
611
612 static inline const char *btf_name_by_offset(c
613 u
614 {
615 return NULL;
616 }
617 static inline u32 *btf_kfunc_id_set_contains(c
618 u
619 s
620
621 {
622 return NULL;
623 }
624 static inline int register_btf_kfunc_id_set(en
625 co
626 {
627 return 0;
628 }
629 static inline s32 btf_find_dtor_kfunc(struct b
630 {
631 return -ENOENT;
632 }
633 static inline int register_btf_id_dtor_kfuncs(
634
635 {
636 return 0;
637 }
638 static inline struct btf_struct_meta *btf_find
639 {
640 return NULL;
641 }
642 static inline bool
643 btf_is_prog_ctx_type(struct bpf_verifier_log *
644 const struct btf_type *t,
645 int arg)
646 {
647 return false;
648 }
649 static inline int get_kern_ctx_btf_id(struct b
650 enum bpf
651 return -EINVAL;
652 }
653 static inline bool btf_types_are_same(const st
654 const st
655 {
656 return false;
657 }
658 static inline int btf_check_iter_arg(struct bt
659 {
660 return -EOPNOTSUPP;
661 }
662 #endif
663
664 static inline bool btf_type_is_struct_ptr(stru
665 {
666 if (!btf_type_is_ptr(t))
667 return false;
668
669 t = btf_type_skip_modifiers(btf, t->ty
670
671 return btf_type_is_struct(t);
672 }
673
674 #endif
675
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