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1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2/* Copyright (C) 2019 Facebook */
3
4#ifndef _GNU_SOURCE
5#define _GNU_SOURCE
6#endif
7#include <errno.h>
8#include <fcntl.h>
9#include <linux/err.h>
10#include <stdbool.h>
11#include <stdio.h>
12#include <stdlib.h>
13#include <string.h>
14#include <unistd.h>
15#include <linux/btf.h>
16#include <sys/types.h>
17#include <sys/stat.h>
18
19#include <bpf/bpf.h>
20#include <bpf/btf.h>
21#include <bpf/hashmap.h>
22#include <bpf/libbpf.h>
23
24#include "json_writer.h"
25#include "main.h"
26
27#define KFUNC_DECL_TAG "bpf_kfunc"
28#define FASTCALL_DECL_TAG "bpf_fastcall"
29
30static const char * const btf_kind_str[NR_BTF_KINDS] = {
31 [BTF_KIND_UNKN] = "UNKNOWN",
32 [BTF_KIND_INT] = "INT",
33 [BTF_KIND_PTR] = "PTR",
34 [BTF_KIND_ARRAY] = "ARRAY",
35 [BTF_KIND_STRUCT] = "STRUCT",
36 [BTF_KIND_UNION] = "UNION",
37 [BTF_KIND_ENUM] = "ENUM",
38 [BTF_KIND_FWD] = "FWD",
39 [BTF_KIND_TYPEDEF] = "TYPEDEF",
40 [BTF_KIND_VOLATILE] = "VOLATILE",
41 [BTF_KIND_CONST] = "CONST",
42 [BTF_KIND_RESTRICT] = "RESTRICT",
43 [BTF_KIND_FUNC] = "FUNC",
44 [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
45 [BTF_KIND_VAR] = "VAR",
46 [BTF_KIND_DATASEC] = "DATASEC",
47 [BTF_KIND_FLOAT] = "FLOAT",
48 [BTF_KIND_DECL_TAG] = "DECL_TAG",
49 [BTF_KIND_TYPE_TAG] = "TYPE_TAG",
50 [BTF_KIND_ENUM64] = "ENUM64",
51};
52
53struct sort_datum {
54 int index;
55 int type_rank;
56 const char *sort_name;
57 const char *own_name;
58 __u64 disambig_hash;
59};
60
61static const char *btf_int_enc_str(__u8 encoding)
62{
63 switch (encoding) {
64 case 0:
65 return "(none)";
66 case BTF_INT_SIGNED:
67 return "SIGNED";
68 case BTF_INT_CHAR:
69 return "CHAR";
70 case BTF_INT_BOOL:
71 return "BOOL";
72 default:
73 return "UNKN";
74 }
75}
76
77static const char *btf_var_linkage_str(__u32 linkage)
78{
79 switch (linkage) {
80 case BTF_VAR_STATIC:
81 return "static";
82 case BTF_VAR_GLOBAL_ALLOCATED:
83 return "global";
84 case BTF_VAR_GLOBAL_EXTERN:
85 return "extern";
86 default:
87 return "(unknown)";
88 }
89}
90
91static const char *btf_func_linkage_str(const struct btf_type *t)
92{
93 switch (btf_vlen(t)) {
94 case BTF_FUNC_STATIC:
95 return "static";
96 case BTF_FUNC_GLOBAL:
97 return "global";
98 case BTF_FUNC_EXTERN:
99 return "extern";
100 default:
101 return "(unknown)";
102 }
103}
104
105static const char *btf_str(const struct btf *btf, __u32 off)
106{
107 if (!off)
108 return "(anon)";
109 return btf__name_by_offset(btf, off) ? : "(invalid)";
110}
111
112static int btf_kind_safe(int kind)
113{
114 return kind <= BTF_KIND_MAX ? kind : BTF_KIND_UNKN;
115}
116
117static int dump_btf_type(const struct btf *btf, __u32 id,
118 const struct btf_type *t)
119{
120 json_writer_t *w = json_wtr;
121 int kind = btf_kind(t);
122
123 if (json_output) {
124 jsonw_start_object(w);
125 jsonw_uint_field(w, "id", id);
126 jsonw_string_field(w, "kind", btf_kind_str[btf_kind_safe(kind)]);
127 jsonw_string_field(w, "name", btf_str(btf, t->name_off));
128 } else {
129 printf("[%u] %s '%s'", id, btf_kind_str[btf_kind_safe(kind)],
130 btf_str(btf, t->name_off));
131 }
132
133 switch (kind) {
134 case BTF_KIND_INT: {
135 __u32 v = *(__u32 *)(t + 1);
136 const char *enc;
137
138 enc = btf_int_enc_str(BTF_INT_ENCODING(v));
139
140 if (json_output) {
141 jsonw_uint_field(w, "size", t->size);
142 jsonw_uint_field(w, "bits_offset", BTF_INT_OFFSET(v));
143 jsonw_uint_field(w, "nr_bits", BTF_INT_BITS(v));
144 jsonw_string_field(w, "encoding", enc);
145 } else {
146 printf(" size=%u bits_offset=%u nr_bits=%u encoding=%s",
147 t->size, BTF_INT_OFFSET(v), BTF_INT_BITS(v),
148 enc);
149 }
150 break;
151 }
152 case BTF_KIND_PTR:
153 case BTF_KIND_CONST:
154 case BTF_KIND_VOLATILE:
155 case BTF_KIND_RESTRICT:
156 case BTF_KIND_TYPEDEF:
157 case BTF_KIND_TYPE_TAG:
158 if (json_output)
159 jsonw_uint_field(w, "type_id", t->type);
160 else
161 printf(" type_id=%u", t->type);
162 break;
163 case BTF_KIND_ARRAY: {
164 const struct btf_array *arr = (const void *)(t + 1);
165
166 if (json_output) {
167 jsonw_uint_field(w, "type_id", arr->type);
168 jsonw_uint_field(w, "index_type_id", arr->index_type);
169 jsonw_uint_field(w, "nr_elems", arr->nelems);
170 } else {
171 printf(" type_id=%u index_type_id=%u nr_elems=%u",
172 arr->type, arr->index_type, arr->nelems);
173 }
174 break;
175 }
176 case BTF_KIND_STRUCT:
177 case BTF_KIND_UNION: {
178 const struct btf_member *m = (const void *)(t + 1);
179 __u16 vlen = BTF_INFO_VLEN(t->info);
180 int i;
181
182 if (json_output) {
183 jsonw_uint_field(w, "size", t->size);
184 jsonw_uint_field(w, "vlen", vlen);
185 jsonw_name(w, "members");
186 jsonw_start_array(w);
187 } else {
188 printf(" size=%u vlen=%u", t->size, vlen);
189 }
190 for (i = 0; i < vlen; i++, m++) {
191 const char *name = btf_str(btf, m->name_off);
192 __u32 bit_off, bit_sz;
193
194 if (BTF_INFO_KFLAG(t->info)) {
195 bit_off = BTF_MEMBER_BIT_OFFSET(m->offset);
196 bit_sz = BTF_MEMBER_BITFIELD_SIZE(m->offset);
197 } else {
198 bit_off = m->offset;
199 bit_sz = 0;
200 }
201
202 if (json_output) {
203 jsonw_start_object(w);
204 jsonw_string_field(w, "name", name);
205 jsonw_uint_field(w, "type_id", m->type);
206 jsonw_uint_field(w, "bits_offset", bit_off);
207 if (bit_sz) {
208 jsonw_uint_field(w, "bitfield_size",
209 bit_sz);
210 }
211 jsonw_end_object(w);
212 } else {
213 printf("\n\t'%s' type_id=%u bits_offset=%u",
214 name, m->type, bit_off);
215 if (bit_sz)
216 printf(" bitfield_size=%u", bit_sz);
217 }
218 }
219 if (json_output)
220 jsonw_end_array(w);
221 break;
222 }
223 case BTF_KIND_ENUM: {
224 const struct btf_enum *v = (const void *)(t + 1);
225 __u16 vlen = BTF_INFO_VLEN(t->info);
226 const char *encoding;
227 int i;
228
229 encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
230 if (json_output) {
231 jsonw_string_field(w, "encoding", encoding);
232 jsonw_uint_field(w, "size", t->size);
233 jsonw_uint_field(w, "vlen", vlen);
234 jsonw_name(w, "values");
235 jsonw_start_array(w);
236 } else {
237 printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
238 }
239 for (i = 0; i < vlen; i++, v++) {
240 const char *name = btf_str(btf, v->name_off);
241
242 if (json_output) {
243 jsonw_start_object(w);
244 jsonw_string_field(w, "name", name);
245 if (btf_kflag(t))
246 jsonw_int_field(w, "val", v->val);
247 else
248 jsonw_uint_field(w, "val", v->val);
249 jsonw_end_object(w);
250 } else {
251 if (btf_kflag(t))
252 printf("\n\t'%s' val=%d", name, v->val);
253 else
254 printf("\n\t'%s' val=%u", name, v->val);
255 }
256 }
257 if (json_output)
258 jsonw_end_array(w);
259 break;
260 }
261 case BTF_KIND_ENUM64: {
262 const struct btf_enum64 *v = btf_enum64(t);
263 __u16 vlen = btf_vlen(t);
264 const char *encoding;
265 int i;
266
267 encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
268 if (json_output) {
269 jsonw_string_field(w, "encoding", encoding);
270 jsonw_uint_field(w, "size", t->size);
271 jsonw_uint_field(w, "vlen", vlen);
272 jsonw_name(w, "values");
273 jsonw_start_array(w);
274 } else {
275 printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
276 }
277 for (i = 0; i < vlen; i++, v++) {
278 const char *name = btf_str(btf, v->name_off);
279 __u64 val = ((__u64)v->val_hi32 << 32) | v->val_lo32;
280
281 if (json_output) {
282 jsonw_start_object(w);
283 jsonw_string_field(w, "name", name);
284 if (btf_kflag(t))
285 jsonw_int_field(w, "val", val);
286 else
287 jsonw_uint_field(w, "val", val);
288 jsonw_end_object(w);
289 } else {
290 if (btf_kflag(t))
291 printf("\n\t'%s' val=%lldLL", name,
292 (long long)val);
293 else
294 printf("\n\t'%s' val=%lluULL", name,
295 (unsigned long long)val);
296 }
297 }
298 if (json_output)
299 jsonw_end_array(w);
300 break;
301 }
302 case BTF_KIND_FWD: {
303 const char *fwd_kind = BTF_INFO_KFLAG(t->info) ? "union"
304 : "struct";
305
306 if (json_output)
307 jsonw_string_field(w, "fwd_kind", fwd_kind);
308 else
309 printf(" fwd_kind=%s", fwd_kind);
310 break;
311 }
312 case BTF_KIND_FUNC: {
313 const char *linkage = btf_func_linkage_str(t);
314
315 if (json_output) {
316 jsonw_uint_field(w, "type_id", t->type);
317 jsonw_string_field(w, "linkage", linkage);
318 } else {
319 printf(" type_id=%u linkage=%s", t->type, linkage);
320 }
321 break;
322 }
323 case BTF_KIND_FUNC_PROTO: {
324 const struct btf_param *p = (const void *)(t + 1);
325 __u16 vlen = BTF_INFO_VLEN(t->info);
326 int i;
327
328 if (json_output) {
329 jsonw_uint_field(w, "ret_type_id", t->type);
330 jsonw_uint_field(w, "vlen", vlen);
331 jsonw_name(w, "params");
332 jsonw_start_array(w);
333 } else {
334 printf(" ret_type_id=%u vlen=%u", t->type, vlen);
335 }
336 for (i = 0; i < vlen; i++, p++) {
337 const char *name = btf_str(btf, p->name_off);
338
339 if (json_output) {
340 jsonw_start_object(w);
341 jsonw_string_field(w, "name", name);
342 jsonw_uint_field(w, "type_id", p->type);
343 jsonw_end_object(w);
344 } else {
345 printf("\n\t'%s' type_id=%u", name, p->type);
346 }
347 }
348 if (json_output)
349 jsonw_end_array(w);
350 break;
351 }
352 case BTF_KIND_VAR: {
353 const struct btf_var *v = (const void *)(t + 1);
354 const char *linkage;
355
356 linkage = btf_var_linkage_str(v->linkage);
357
358 if (json_output) {
359 jsonw_uint_field(w, "type_id", t->type);
360 jsonw_string_field(w, "linkage", linkage);
361 } else {
362 printf(" type_id=%u, linkage=%s", t->type, linkage);
363 }
364 break;
365 }
366 case BTF_KIND_DATASEC: {
367 const struct btf_var_secinfo *v = (const void *)(t + 1);
368 const struct btf_type *vt;
369 __u16 vlen = BTF_INFO_VLEN(t->info);
370 int i;
371
372 if (json_output) {
373 jsonw_uint_field(w, "size", t->size);
374 jsonw_uint_field(w, "vlen", vlen);
375 jsonw_name(w, "vars");
376 jsonw_start_array(w);
377 } else {
378 printf(" size=%u vlen=%u", t->size, vlen);
379 }
380 for (i = 0; i < vlen; i++, v++) {
381 if (json_output) {
382 jsonw_start_object(w);
383 jsonw_uint_field(w, "type_id", v->type);
384 jsonw_uint_field(w, "offset", v->offset);
385 jsonw_uint_field(w, "size", v->size);
386 jsonw_end_object(w);
387 } else {
388 printf("\n\ttype_id=%u offset=%u size=%u",
389 v->type, v->offset, v->size);
390
391 if (v->type < btf__type_cnt(btf)) {
392 vt = btf__type_by_id(btf, v->type);
393 printf(" (%s '%s')",
394 btf_kind_str[btf_kind_safe(btf_kind(vt))],
395 btf_str(btf, vt->name_off));
396 }
397 }
398 }
399 if (json_output)
400 jsonw_end_array(w);
401 break;
402 }
403 case BTF_KIND_FLOAT: {
404 if (json_output)
405 jsonw_uint_field(w, "size", t->size);
406 else
407 printf(" size=%u", t->size);
408 break;
409 }
410 case BTF_KIND_DECL_TAG: {
411 const struct btf_decl_tag *tag = (const void *)(t + 1);
412
413 if (json_output) {
414 jsonw_uint_field(w, "type_id", t->type);
415 jsonw_int_field(w, "component_idx", tag->component_idx);
416 } else {
417 printf(" type_id=%u component_idx=%d", t->type, tag->component_idx);
418 }
419 break;
420 }
421 default:
422 break;
423 }
424
425 if (json_output)
426 jsonw_end_object(json_wtr);
427 else
428 printf("\n");
429
430 return 0;
431}
432
433static int dump_btf_raw(const struct btf *btf,
434 __u32 *root_type_ids, int root_type_cnt)
435{
436 const struct btf_type *t;
437 int i;
438
439 if (json_output) {
440 jsonw_start_object(json_wtr);
441 jsonw_name(json_wtr, "types");
442 jsonw_start_array(json_wtr);
443 }
444
445 if (root_type_cnt) {
446 for (i = 0; i < root_type_cnt; i++) {
447 t = btf__type_by_id(btf, root_type_ids[i]);
448 dump_btf_type(btf, root_type_ids[i], t);
449 }
450 } else {
451 const struct btf *base;
452 int cnt = btf__type_cnt(btf);
453 int start_id = 1;
454
455 base = btf__base_btf(btf);
456 if (base)
457 start_id = btf__type_cnt(base);
458
459 for (i = start_id; i < cnt; i++) {
460 t = btf__type_by_id(btf, i);
461 dump_btf_type(btf, i, t);
462 }
463 }
464
465 if (json_output) {
466 jsonw_end_array(json_wtr);
467 jsonw_end_object(json_wtr);
468 }
469 return 0;
470}
471
472struct ptr_array {
473 __u32 cnt;
474 __u32 cap;
475 const void **elems;
476};
477
478static int ptr_array_push(const void *ptr, struct ptr_array *arr)
479{
480 __u32 new_cap;
481 void *tmp;
482
483 if (arr->cnt == arr->cap) {
484 new_cap = (arr->cap ?: 16) * 2;
485 tmp = realloc(arr->elems, sizeof(*arr->elems) * new_cap);
486 if (!tmp)
487 return -ENOMEM;
488 arr->elems = tmp;
489 arr->cap = new_cap;
490 }
491 arr->elems[arr->cnt++] = ptr;
492 return 0;
493}
494
495static void ptr_array_free(struct ptr_array *arr)
496{
497 free(arr->elems);
498}
499
500static int cmp_kfuncs(const void *pa, const void *pb, void *ctx)
501{
502 struct btf *btf = ctx;
503 const struct btf_type *a = *(void **)pa;
504 const struct btf_type *b = *(void **)pb;
505
506 return strcmp(btf__str_by_offset(btf, a->name_off),
507 btf__str_by_offset(btf, b->name_off));
508}
509
510static int dump_btf_kfuncs(struct btf_dump *d, const struct btf *btf)
511{
512 LIBBPF_OPTS(btf_dump_emit_type_decl_opts, opts);
513 __u32 cnt = btf__type_cnt(btf), i, j;
514 struct ptr_array fastcalls = {};
515 struct ptr_array kfuncs = {};
516 int err = 0;
517
518 printf("\n/* BPF kfuncs */\n");
519 printf("#ifndef BPF_NO_KFUNC_PROTOTYPES\n");
520
521 for (i = 1; i < cnt; i++) {
522 const struct btf_type *t = btf__type_by_id(btf, i);
523 const struct btf_type *ft;
524 const char *name;
525
526 if (!btf_is_decl_tag(t))
527 continue;
528
529 if (btf_decl_tag(t)->component_idx != -1)
530 continue;
531
532 ft = btf__type_by_id(btf, t->type);
533 if (!btf_is_func(ft))
534 continue;
535
536 name = btf__name_by_offset(btf, t->name_off);
537 if (strncmp(name, KFUNC_DECL_TAG, sizeof(KFUNC_DECL_TAG)) == 0) {
538 err = ptr_array_push(ft, &kfuncs);
539 if (err)
540 goto out;
541 }
542
543 if (strncmp(name, FASTCALL_DECL_TAG, sizeof(FASTCALL_DECL_TAG)) == 0) {
544 err = ptr_array_push(ft, &fastcalls);
545 if (err)
546 goto out;
547 }
548 }
549
550 /* Sort kfuncs by name for improved vmlinux.h stability */
551 qsort_r(kfuncs.elems, kfuncs.cnt, sizeof(*kfuncs.elems), cmp_kfuncs, (void *)btf);
552 for (i = 0; i < kfuncs.cnt; i++) {
553 const struct btf_type *t = kfuncs.elems[i];
554
555 printf("extern ");
556
557 /* Assume small amount of fastcall kfuncs */
558 for (j = 0; j < fastcalls.cnt; j++) {
559 if (fastcalls.elems[j] == t) {
560 printf("__bpf_fastcall ");
561 break;
562 }
563 }
564
565 opts.field_name = btf__name_by_offset(btf, t->name_off);
566 err = btf_dump__emit_type_decl(d, t->type, &opts);
567 if (err)
568 goto out;
569
570 printf(" __weak __ksym;\n");
571 }
572
573 printf("#endif\n\n");
574
575out:
576 ptr_array_free(&fastcalls);
577 ptr_array_free(&kfuncs);
578 return err;
579}
580
581static void __printf(2, 0) btf_dump_printf(void *ctx,
582 const char *fmt, va_list args)
583{
584 vfprintf(stdout, fmt, args);
585}
586
587static int btf_type_rank(const struct btf *btf, __u32 index, bool has_name)
588{
589 const struct btf_type *t = btf__type_by_id(btf, index);
590 const int kind = btf_kind(t);
591 const int max_rank = 10;
592
593 if (t->name_off)
594 has_name = true;
595
596 switch (kind) {
597 case BTF_KIND_ENUM:
598 case BTF_KIND_ENUM64:
599 return has_name ? 1 : 0;
600 case BTF_KIND_INT:
601 case BTF_KIND_FLOAT:
602 return 2;
603 case BTF_KIND_STRUCT:
604 case BTF_KIND_UNION:
605 return has_name ? 3 : max_rank;
606 case BTF_KIND_FUNC_PROTO:
607 return has_name ? 4 : max_rank;
608 case BTF_KIND_ARRAY:
609 if (has_name)
610 return btf_type_rank(btf, btf_array(t)->type, has_name);
611 return max_rank;
612 case BTF_KIND_TYPE_TAG:
613 case BTF_KIND_CONST:
614 case BTF_KIND_PTR:
615 case BTF_KIND_VOLATILE:
616 case BTF_KIND_RESTRICT:
617 case BTF_KIND_TYPEDEF:
618 case BTF_KIND_DECL_TAG:
619 if (has_name)
620 return btf_type_rank(btf, t->type, has_name);
621 return max_rank;
622 default:
623 return max_rank;
624 }
625}
626
627static const char *btf_type_sort_name(const struct btf *btf, __u32 index, bool from_ref)
628{
629 const struct btf_type *t = btf__type_by_id(btf, index);
630
631 switch (btf_kind(t)) {
632 case BTF_KIND_ENUM:
633 case BTF_KIND_ENUM64: {
634 int name_off = t->name_off;
635
636 if (!from_ref && !name_off && btf_vlen(t))
637 name_off = btf_kind(t) == BTF_KIND_ENUM64 ?
638 btf_enum64(t)->name_off :
639 btf_enum(t)->name_off;
640
641 return btf__name_by_offset(btf, name_off);
642 }
643 case BTF_KIND_ARRAY:
644 return btf_type_sort_name(btf, btf_array(t)->type, true);
645 case BTF_KIND_TYPE_TAG:
646 case BTF_KIND_CONST:
647 case BTF_KIND_PTR:
648 case BTF_KIND_VOLATILE:
649 case BTF_KIND_RESTRICT:
650 case BTF_KIND_TYPEDEF:
651 case BTF_KIND_DECL_TAG:
652 return btf_type_sort_name(btf, t->type, true);
653 default:
654 return btf__name_by_offset(btf, t->name_off);
655 }
656 return NULL;
657}
658
659static __u64 hasher(__u64 hash, __u64 val)
660{
661 return hash * 31 + val;
662}
663
664static __u64 btf_name_hasher(__u64 hash, const struct btf *btf, __u32 name_off)
665{
666 if (!name_off)
667 return hash;
668
669 return hasher(hash, str_hash(btf__name_by_offset(btf, name_off)));
670}
671
672static __u64 btf_type_disambig_hash(const struct btf *btf, __u32 id, bool include_members)
673{
674 const struct btf_type *t = btf__type_by_id(btf, id);
675 int i;
676 size_t hash = 0;
677
678 hash = btf_name_hasher(hash, btf, t->name_off);
679
680 switch (btf_kind(t)) {
681 case BTF_KIND_ENUM:
682 case BTF_KIND_ENUM64:
683 for (i = 0; i < btf_vlen(t); i++) {
684 __u32 name_off = btf_is_enum(t) ?
685 btf_enum(t)[i].name_off :
686 btf_enum64(t)[i].name_off;
687
688 hash = btf_name_hasher(hash, btf, name_off);
689 }
690 break;
691 case BTF_KIND_STRUCT:
692 case BTF_KIND_UNION:
693 if (!include_members)
694 break;
695 for (i = 0; i < btf_vlen(t); i++) {
696 const struct btf_member *m = btf_members(t) + i;
697
698 hash = btf_name_hasher(hash, btf, m->name_off);
699 /* resolve field type's name and hash it as well */
700 hash = hasher(hash, btf_type_disambig_hash(btf, m->type, false));
701 }
702 break;
703 case BTF_KIND_TYPE_TAG:
704 case BTF_KIND_CONST:
705 case BTF_KIND_PTR:
706 case BTF_KIND_VOLATILE:
707 case BTF_KIND_RESTRICT:
708 case BTF_KIND_TYPEDEF:
709 case BTF_KIND_DECL_TAG:
710 hash = hasher(hash, btf_type_disambig_hash(btf, t->type, include_members));
711 break;
712 case BTF_KIND_ARRAY: {
713 struct btf_array *arr = btf_array(t);
714
715 hash = hasher(hash, arr->nelems);
716 hash = hasher(hash, btf_type_disambig_hash(btf, arr->type, include_members));
717 break;
718 }
719 default:
720 break;
721 }
722 return hash;
723}
724
725static int btf_type_compare(const void *left, const void *right)
726{
727 const struct sort_datum *d1 = (const struct sort_datum *)left;
728 const struct sort_datum *d2 = (const struct sort_datum *)right;
729 int r;
730
731 r = d1->type_rank - d2->type_rank;
732 r = r ?: strcmp(d1->sort_name, d2->sort_name);
733 r = r ?: strcmp(d1->own_name, d2->own_name);
734 if (r)
735 return r;
736
737 if (d1->disambig_hash != d2->disambig_hash)
738 return d1->disambig_hash < d2->disambig_hash ? -1 : 1;
739
740 return d1->index - d2->index;
741}
742
743static struct sort_datum *sort_btf_c(const struct btf *btf)
744{
745 struct sort_datum *datums;
746 int n;
747
748 n = btf__type_cnt(btf);
749 datums = malloc(sizeof(struct sort_datum) * n);
750 if (!datums)
751 return NULL;
752
753 for (int i = 0; i < n; ++i) {
754 struct sort_datum *d = datums + i;
755 const struct btf_type *t = btf__type_by_id(btf, i);
756
757 d->index = i;
758 d->type_rank = btf_type_rank(btf, i, false);
759 d->sort_name = btf_type_sort_name(btf, i, false);
760 d->own_name = btf__name_by_offset(btf, t->name_off);
761 d->disambig_hash = btf_type_disambig_hash(btf, i, true);
762 }
763
764 qsort(datums, n, sizeof(struct sort_datum), btf_type_compare);
765
766 return datums;
767}
768
769static int dump_btf_c(const struct btf *btf,
770 __u32 *root_type_ids, int root_type_cnt, bool sort_dump)
771{
772 struct sort_datum *datums = NULL;
773 struct btf_dump *d;
774 int err = 0, i;
775
776 d = btf_dump__new(btf, btf_dump_printf, NULL, NULL);
777 if (!d)
778 return -errno;
779
780 printf("#ifndef __VMLINUX_H__\n");
781 printf("#define __VMLINUX_H__\n");
782 printf("\n");
783 printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
784 printf("#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)\n");
785 printf("#endif\n\n");
786 printf("#ifndef __ksym\n");
787 printf("#define __ksym __attribute__((section(\".ksyms\")))\n");
788 printf("#endif\n\n");
789 printf("#ifndef __weak\n");
790 printf("#define __weak __attribute__((weak))\n");
791 printf("#endif\n\n");
792 printf("#ifndef __bpf_fastcall\n");
793 printf("#if __has_attribute(bpf_fastcall)\n");
794 printf("#define __bpf_fastcall __attribute__((bpf_fastcall))\n");
795 printf("#else\n");
796 printf("#define __bpf_fastcall\n");
797 printf("#endif\n");
798 printf("#endif\n\n");
799
800 if (root_type_cnt) {
801 for (i = 0; i < root_type_cnt; i++) {
802 err = btf_dump__dump_type(d, root_type_ids[i]);
803 if (err)
804 goto done;
805 }
806 } else {
807 int cnt = btf__type_cnt(btf);
808
809 if (sort_dump)
810 datums = sort_btf_c(btf);
811 for (i = 1; i < cnt; i++) {
812 int idx = datums ? datums[i].index : i;
813
814 err = btf_dump__dump_type(d, idx);
815 if (err)
816 goto done;
817 }
818
819 err = dump_btf_kfuncs(d, btf);
820 if (err)
821 goto done;
822 }
823
824 printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
825 printf("#pragma clang attribute pop\n");
826 printf("#endif\n");
827 printf("\n");
828 printf("#endif /* __VMLINUX_H__ */\n");
829
830done:
831 free(datums);
832 btf_dump__free(d);
833 return err;
834}
835
836static const char sysfs_vmlinux[] = "/sys/kernel/btf/vmlinux";
837
838static struct btf *get_vmlinux_btf_from_sysfs(void)
839{
840 struct btf *base;
841
842 base = btf__parse(sysfs_vmlinux, NULL);
843 if (!base)
844 p_err("failed to parse vmlinux BTF at '%s': %d\n",
845 sysfs_vmlinux, -errno);
846
847 return base;
848}
849
850#define BTF_NAME_BUFF_LEN 64
851
852static bool btf_is_kernel_module(__u32 btf_id)
853{
854 struct bpf_btf_info btf_info = {};
855 char btf_name[BTF_NAME_BUFF_LEN];
856 int btf_fd;
857 __u32 len;
858 int err;
859
860 btf_fd = bpf_btf_get_fd_by_id(btf_id);
861 if (btf_fd < 0) {
862 p_err("can't get BTF object by id (%u): %s", btf_id, strerror(errno));
863 return false;
864 }
865
866 len = sizeof(btf_info);
867 btf_info.name = ptr_to_u64(btf_name);
868 btf_info.name_len = sizeof(btf_name);
869 err = bpf_btf_get_info_by_fd(btf_fd, &btf_info, &len);
870 close(btf_fd);
871 if (err) {
872 p_err("can't get BTF (ID %u) object info: %s", btf_id, strerror(errno));
873 return false;
874 }
875
876 return btf_info.kernel_btf && strncmp(btf_name, "vmlinux", sizeof(btf_name)) != 0;
877}
878
879static int do_dump(int argc, char **argv)
880{
881 bool dump_c = false, sort_dump_c = true;
882 struct btf *btf = NULL, *base = NULL;
883 __u32 root_type_ids[2];
884 int root_type_cnt = 0;
885 __u32 btf_id = -1;
886 const char *src;
887 int fd = -1;
888 int err = 0;
889
890 if (!REQ_ARGS(2)) {
891 usage();
892 return -1;
893 }
894 src = GET_ARG();
895 if (is_prefix(src, "map")) {
896 struct bpf_map_info info = {};
897 __u32 len = sizeof(info);
898
899 if (!REQ_ARGS(2)) {
900 usage();
901 return -1;
902 }
903
904 fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
905 if (fd < 0)
906 return -1;
907
908 btf_id = info.btf_id;
909 if (argc && is_prefix(*argv, "key")) {
910 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
911 NEXT_ARG();
912 } else if (argc && is_prefix(*argv, "value")) {
913 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
914 NEXT_ARG();
915 } else if (argc && is_prefix(*argv, "all")) {
916 NEXT_ARG();
917 } else if (argc && is_prefix(*argv, "kv")) {
918 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
919 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
920 NEXT_ARG();
921 } else {
922 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
923 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
924 }
925 } else if (is_prefix(src, "prog")) {
926 struct bpf_prog_info info = {};
927 __u32 len = sizeof(info);
928
929 if (!REQ_ARGS(2)) {
930 usage();
931 return -1;
932 }
933
934 fd = prog_parse_fd(&argc, &argv);
935 if (fd < 0)
936 return -1;
937
938 err = bpf_prog_get_info_by_fd(fd, &info, &len);
939 if (err) {
940 p_err("can't get prog info: %s", strerror(errno));
941 goto done;
942 }
943
944 btf_id = info.btf_id;
945 } else if (is_prefix(src, "id")) {
946 char *endptr;
947
948 btf_id = strtoul(*argv, &endptr, 0);
949 if (*endptr) {
950 p_err("can't parse %s as ID", *argv);
951 return -1;
952 }
953 NEXT_ARG();
954 } else if (is_prefix(src, "file")) {
955 const char sysfs_prefix[] = "/sys/kernel/btf/";
956
957 if (!base_btf &&
958 strncmp(*argv, sysfs_prefix, sizeof(sysfs_prefix) - 1) == 0 &&
959 strcmp(*argv, sysfs_vmlinux) != 0)
960 base = get_vmlinux_btf_from_sysfs();
961
962 btf = btf__parse_split(*argv, base ?: base_btf);
963 if (!btf) {
964 err = -errno;
965 p_err("failed to load BTF from %s: %s",
966 *argv, strerror(errno));
967 goto done;
968 }
969 NEXT_ARG();
970 } else {
971 err = -1;
972 p_err("unrecognized BTF source specifier: '%s'", src);
973 goto done;
974 }
975
976 while (argc) {
977 if (is_prefix(*argv, "format")) {
978 NEXT_ARG();
979 if (argc < 1) {
980 p_err("expecting value for 'format' option\n");
981 err = -EINVAL;
982 goto done;
983 }
984 if (strcmp(*argv, "c") == 0) {
985 dump_c = true;
986 } else if (strcmp(*argv, "raw") == 0) {
987 dump_c = false;
988 } else {
989 p_err("unrecognized format specifier: '%s', possible values: raw, c",
990 *argv);
991 err = -EINVAL;
992 goto done;
993 }
994 NEXT_ARG();
995 } else if (is_prefix(*argv, "unsorted")) {
996 sort_dump_c = false;
997 NEXT_ARG();
998 } else {
999 p_err("unrecognized option: '%s'", *argv);
1000 err = -EINVAL;
1001 goto done;
1002 }
1003 }
1004
1005 if (!btf) {
1006 if (!base_btf && btf_is_kernel_module(btf_id)) {
1007 p_info("Warning: valid base BTF was not specified with -B option, falling back to standard base BTF (%s)",
1008 sysfs_vmlinux);
1009 base_btf = get_vmlinux_btf_from_sysfs();
1010 }
1011
1012 btf = btf__load_from_kernel_by_id_split(btf_id, base_btf);
1013 if (!btf) {
1014 err = -errno;
1015 p_err("get btf by id (%u): %s", btf_id, strerror(errno));
1016 goto done;
1017 }
1018 }
1019
1020 if (dump_c) {
1021 if (json_output) {
1022 p_err("JSON output for C-syntax dump is not supported");
1023 err = -ENOTSUP;
1024 goto done;
1025 }
1026 err = dump_btf_c(btf, root_type_ids, root_type_cnt, sort_dump_c);
1027 } else {
1028 err = dump_btf_raw(btf, root_type_ids, root_type_cnt);
1029 }
1030
1031done:
1032 close(fd);
1033 btf__free(btf);
1034 btf__free(base);
1035 return err;
1036}
1037
1038static int btf_parse_fd(int *argc, char ***argv)
1039{
1040 unsigned int id;
1041 char *endptr;
1042 int fd;
1043
1044 if (!is_prefix(*argv[0], "id")) {
1045 p_err("expected 'id', got: '%s'?", **argv);
1046 return -1;
1047 }
1048 NEXT_ARGP();
1049
1050 id = strtoul(**argv, &endptr, 0);
1051 if (*endptr) {
1052 p_err("can't parse %s as ID", **argv);
1053 return -1;
1054 }
1055 NEXT_ARGP();
1056
1057 fd = bpf_btf_get_fd_by_id(id);
1058 if (fd < 0)
1059 p_err("can't get BTF object by id (%u): %s",
1060 id, strerror(errno));
1061
1062 return fd;
1063}
1064
1065static int
1066build_btf_type_table(struct hashmap *tab, enum bpf_obj_type type,
1067 void *info, __u32 *len)
1068{
1069 static const char * const names[] = {
1070 [BPF_OBJ_UNKNOWN] = "unknown",
1071 [BPF_OBJ_PROG] = "prog",
1072 [BPF_OBJ_MAP] = "map",
1073 };
1074 __u32 btf_id, id = 0;
1075 int err;
1076 int fd;
1077
1078 while (true) {
1079 switch (type) {
1080 case BPF_OBJ_PROG:
1081 err = bpf_prog_get_next_id(id, &id);
1082 break;
1083 case BPF_OBJ_MAP:
1084 err = bpf_map_get_next_id(id, &id);
1085 break;
1086 default:
1087 err = -1;
1088 p_err("unexpected object type: %d", type);
1089 goto err_free;
1090 }
1091 if (err) {
1092 if (errno == ENOENT) {
1093 err = 0;
1094 break;
1095 }
1096 p_err("can't get next %s: %s%s", names[type],
1097 strerror(errno),
1098 errno == EINVAL ? " -- kernel too old?" : "");
1099 goto err_free;
1100 }
1101
1102 switch (type) {
1103 case BPF_OBJ_PROG:
1104 fd = bpf_prog_get_fd_by_id(id);
1105 break;
1106 case BPF_OBJ_MAP:
1107 fd = bpf_map_get_fd_by_id(id);
1108 break;
1109 default:
1110 err = -1;
1111 p_err("unexpected object type: %d", type);
1112 goto err_free;
1113 }
1114 if (fd < 0) {
1115 if (errno == ENOENT)
1116 continue;
1117 p_err("can't get %s by id (%u): %s", names[type], id,
1118 strerror(errno));
1119 err = -1;
1120 goto err_free;
1121 }
1122
1123 memset(info, 0, *len);
1124 if (type == BPF_OBJ_PROG)
1125 err = bpf_prog_get_info_by_fd(fd, info, len);
1126 else
1127 err = bpf_map_get_info_by_fd(fd, info, len);
1128 close(fd);
1129 if (err) {
1130 p_err("can't get %s info: %s", names[type],
1131 strerror(errno));
1132 goto err_free;
1133 }
1134
1135 switch (type) {
1136 case BPF_OBJ_PROG:
1137 btf_id = ((struct bpf_prog_info *)info)->btf_id;
1138 break;
1139 case BPF_OBJ_MAP:
1140 btf_id = ((struct bpf_map_info *)info)->btf_id;
1141 break;
1142 default:
1143 err = -1;
1144 p_err("unexpected object type: %d", type);
1145 goto err_free;
1146 }
1147 if (!btf_id)
1148 continue;
1149
1150 err = hashmap__append(tab, btf_id, id);
1151 if (err) {
1152 p_err("failed to append entry to hashmap for BTF ID %u, object ID %u: %s",
1153 btf_id, id, strerror(-err));
1154 goto err_free;
1155 }
1156 }
1157
1158 return 0;
1159
1160err_free:
1161 hashmap__free(tab);
1162 return err;
1163}
1164
1165static int
1166build_btf_tables(struct hashmap *btf_prog_table,
1167 struct hashmap *btf_map_table)
1168{
1169 struct bpf_prog_info prog_info;
1170 __u32 prog_len = sizeof(prog_info);
1171 struct bpf_map_info map_info;
1172 __u32 map_len = sizeof(map_info);
1173 int err = 0;
1174
1175 err = build_btf_type_table(btf_prog_table, BPF_OBJ_PROG, &prog_info,
1176 &prog_len);
1177 if (err)
1178 return err;
1179
1180 err = build_btf_type_table(btf_map_table, BPF_OBJ_MAP, &map_info,
1181 &map_len);
1182 if (err) {
1183 hashmap__free(btf_prog_table);
1184 return err;
1185 }
1186
1187 return 0;
1188}
1189
1190static void
1191show_btf_plain(struct bpf_btf_info *info, int fd,
1192 struct hashmap *btf_prog_table,
1193 struct hashmap *btf_map_table)
1194{
1195 struct hashmap_entry *entry;
1196 const char *name = u64_to_ptr(info->name);
1197 int n;
1198
1199 printf("%u: ", info->id);
1200 if (info->kernel_btf)
1201 printf("name [%s] ", name);
1202 else if (name && name[0])
1203 printf("name %s ", name);
1204 else
1205 printf("name <anon> ");
1206 printf("size %uB", info->btf_size);
1207
1208 n = 0;
1209 hashmap__for_each_key_entry(btf_prog_table, entry, info->id) {
1210 printf("%s%lu", n++ == 0 ? " prog_ids " : ",", entry->value);
1211 }
1212
1213 n = 0;
1214 hashmap__for_each_key_entry(btf_map_table, entry, info->id) {
1215 printf("%s%lu", n++ == 0 ? " map_ids " : ",", entry->value);
1216 }
1217
1218 emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
1219
1220 printf("\n");
1221}
1222
1223static void
1224show_btf_json(struct bpf_btf_info *info, int fd,
1225 struct hashmap *btf_prog_table,
1226 struct hashmap *btf_map_table)
1227{
1228 struct hashmap_entry *entry;
1229 const char *name = u64_to_ptr(info->name);
1230
1231 jsonw_start_object(json_wtr); /* btf object */
1232 jsonw_uint_field(json_wtr, "id", info->id);
1233 jsonw_uint_field(json_wtr, "size", info->btf_size);
1234
1235 jsonw_name(json_wtr, "prog_ids");
1236 jsonw_start_array(json_wtr); /* prog_ids */
1237 hashmap__for_each_key_entry(btf_prog_table, entry, info->id) {
1238 jsonw_uint(json_wtr, entry->value);
1239 }
1240 jsonw_end_array(json_wtr); /* prog_ids */
1241
1242 jsonw_name(json_wtr, "map_ids");
1243 jsonw_start_array(json_wtr); /* map_ids */
1244 hashmap__for_each_key_entry(btf_map_table, entry, info->id) {
1245 jsonw_uint(json_wtr, entry->value);
1246 }
1247 jsonw_end_array(json_wtr); /* map_ids */
1248
1249 emit_obj_refs_json(refs_table, info->id, json_wtr); /* pids */
1250
1251 jsonw_bool_field(json_wtr, "kernel", info->kernel_btf);
1252
1253 if (name && name[0])
1254 jsonw_string_field(json_wtr, "name", name);
1255
1256 jsonw_end_object(json_wtr); /* btf object */
1257}
1258
1259static int
1260show_btf(int fd, struct hashmap *btf_prog_table,
1261 struct hashmap *btf_map_table)
1262{
1263 struct bpf_btf_info info;
1264 __u32 len = sizeof(info);
1265 char name[64];
1266 int err;
1267
1268 memset(&info, 0, sizeof(info));
1269 err = bpf_btf_get_info_by_fd(fd, &info, &len);
1270 if (err) {
1271 p_err("can't get BTF object info: %s", strerror(errno));
1272 return -1;
1273 }
1274 /* if kernel support emitting BTF object name, pass name pointer */
1275 if (info.name_len) {
1276 memset(&info, 0, sizeof(info));
1277 info.name_len = sizeof(name);
1278 info.name = ptr_to_u64(name);
1279 len = sizeof(info);
1280
1281 err = bpf_btf_get_info_by_fd(fd, &info, &len);
1282 if (err) {
1283 p_err("can't get BTF object info: %s", strerror(errno));
1284 return -1;
1285 }
1286 }
1287
1288 if (json_output)
1289 show_btf_json(&info, fd, btf_prog_table, btf_map_table);
1290 else
1291 show_btf_plain(&info, fd, btf_prog_table, btf_map_table);
1292
1293 return 0;
1294}
1295
1296static int do_show(int argc, char **argv)
1297{
1298 struct hashmap *btf_prog_table;
1299 struct hashmap *btf_map_table;
1300 int err, fd = -1;
1301 __u32 id = 0;
1302
1303 if (argc == 2) {
1304 fd = btf_parse_fd(&argc, &argv);
1305 if (fd < 0)
1306 return -1;
1307 }
1308
1309 if (argc) {
1310 if (fd >= 0)
1311 close(fd);
1312 return BAD_ARG();
1313 }
1314
1315 btf_prog_table = hashmap__new(hash_fn_for_key_as_id,
1316 equal_fn_for_key_as_id, NULL);
1317 btf_map_table = hashmap__new(hash_fn_for_key_as_id,
1318 equal_fn_for_key_as_id, NULL);
1319 if (IS_ERR(btf_prog_table) || IS_ERR(btf_map_table)) {
1320 hashmap__free(btf_prog_table);
1321 hashmap__free(btf_map_table);
1322 if (fd >= 0)
1323 close(fd);
1324 p_err("failed to create hashmap for object references");
1325 return -1;
1326 }
1327 err = build_btf_tables(btf_prog_table, btf_map_table);
1328 if (err) {
1329 if (fd >= 0)
1330 close(fd);
1331 return err;
1332 }
1333 build_obj_refs_table(&refs_table, BPF_OBJ_BTF);
1334
1335 if (fd >= 0) {
1336 err = show_btf(fd, btf_prog_table, btf_map_table);
1337 close(fd);
1338 goto exit_free;
1339 }
1340
1341 if (json_output)
1342 jsonw_start_array(json_wtr); /* root array */
1343
1344 while (true) {
1345 err = bpf_btf_get_next_id(id, &id);
1346 if (err) {
1347 if (errno == ENOENT) {
1348 err = 0;
1349 break;
1350 }
1351 p_err("can't get next BTF object: %s%s",
1352 strerror(errno),
1353 errno == EINVAL ? " -- kernel too old?" : "");
1354 err = -1;
1355 break;
1356 }
1357
1358 fd = bpf_btf_get_fd_by_id(id);
1359 if (fd < 0) {
1360 if (errno == ENOENT)
1361 continue;
1362 p_err("can't get BTF object by id (%u): %s",
1363 id, strerror(errno));
1364 err = -1;
1365 break;
1366 }
1367
1368 err = show_btf(fd, btf_prog_table, btf_map_table);
1369 close(fd);
1370 if (err)
1371 break;
1372 }
1373
1374 if (json_output)
1375 jsonw_end_array(json_wtr); /* root array */
1376
1377exit_free:
1378 hashmap__free(btf_prog_table);
1379 hashmap__free(btf_map_table);
1380 delete_obj_refs_table(refs_table);
1381
1382 return err;
1383}
1384
1385static int do_help(int argc, char **argv)
1386{
1387 if (json_output) {
1388 jsonw_null(json_wtr);
1389 return 0;
1390 }
1391
1392 fprintf(stderr,
1393 "Usage: %1$s %2$s { show | list } [id BTF_ID]\n"
1394 " %1$s %2$s dump BTF_SRC [format FORMAT]\n"
1395 " %1$s %2$s help\n"
1396 "\n"
1397 " BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }\n"
1398 " FORMAT := { raw | c [unsorted] }\n"
1399 " " HELP_SPEC_MAP "\n"
1400 " " HELP_SPEC_PROGRAM "\n"
1401 " " HELP_SPEC_OPTIONS " |\n"
1402 " {-B|--base-btf} }\n"
1403 "",
1404 bin_name, "btf");
1405
1406 return 0;
1407}
1408
1409static const struct cmd cmds[] = {
1410 { "show", do_show },
1411 { "list", do_show },
1412 { "help", do_help },
1413 { "dump", do_dump },
1414 { 0 }
1415};
1416
1417int do_btf(int argc, char **argv)
1418{
1419 return cmd_select(cmds, argc, argv, do_help);
1420}
1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2/* Copyright (C) 2019 Facebook */
3
4#include <errno.h>
5#include <fcntl.h>
6#include <linux/err.h>
7#include <stdbool.h>
8#include <stdio.h>
9#include <string.h>
10#include <unistd.h>
11#include <linux/btf.h>
12#include <sys/types.h>
13#include <sys/stat.h>
14
15#include <bpf/bpf.h>
16#include <bpf/btf.h>
17#include <bpf/hashmap.h>
18#include <bpf/libbpf.h>
19
20#include "json_writer.h"
21#include "main.h"
22
23static const char * const btf_kind_str[NR_BTF_KINDS] = {
24 [BTF_KIND_UNKN] = "UNKNOWN",
25 [BTF_KIND_INT] = "INT",
26 [BTF_KIND_PTR] = "PTR",
27 [BTF_KIND_ARRAY] = "ARRAY",
28 [BTF_KIND_STRUCT] = "STRUCT",
29 [BTF_KIND_UNION] = "UNION",
30 [BTF_KIND_ENUM] = "ENUM",
31 [BTF_KIND_FWD] = "FWD",
32 [BTF_KIND_TYPEDEF] = "TYPEDEF",
33 [BTF_KIND_VOLATILE] = "VOLATILE",
34 [BTF_KIND_CONST] = "CONST",
35 [BTF_KIND_RESTRICT] = "RESTRICT",
36 [BTF_KIND_FUNC] = "FUNC",
37 [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
38 [BTF_KIND_VAR] = "VAR",
39 [BTF_KIND_DATASEC] = "DATASEC",
40 [BTF_KIND_FLOAT] = "FLOAT",
41 [BTF_KIND_DECL_TAG] = "DECL_TAG",
42 [BTF_KIND_TYPE_TAG] = "TYPE_TAG",
43 [BTF_KIND_ENUM64] = "ENUM64",
44};
45
46static const char *btf_int_enc_str(__u8 encoding)
47{
48 switch (encoding) {
49 case 0:
50 return "(none)";
51 case BTF_INT_SIGNED:
52 return "SIGNED";
53 case BTF_INT_CHAR:
54 return "CHAR";
55 case BTF_INT_BOOL:
56 return "BOOL";
57 default:
58 return "UNKN";
59 }
60}
61
62static const char *btf_var_linkage_str(__u32 linkage)
63{
64 switch (linkage) {
65 case BTF_VAR_STATIC:
66 return "static";
67 case BTF_VAR_GLOBAL_ALLOCATED:
68 return "global";
69 case BTF_VAR_GLOBAL_EXTERN:
70 return "extern";
71 default:
72 return "(unknown)";
73 }
74}
75
76static const char *btf_func_linkage_str(const struct btf_type *t)
77{
78 switch (btf_vlen(t)) {
79 case BTF_FUNC_STATIC:
80 return "static";
81 case BTF_FUNC_GLOBAL:
82 return "global";
83 case BTF_FUNC_EXTERN:
84 return "extern";
85 default:
86 return "(unknown)";
87 }
88}
89
90static const char *btf_str(const struct btf *btf, __u32 off)
91{
92 if (!off)
93 return "(anon)";
94 return btf__name_by_offset(btf, off) ? : "(invalid)";
95}
96
97static int btf_kind_safe(int kind)
98{
99 return kind <= BTF_KIND_MAX ? kind : BTF_KIND_UNKN;
100}
101
102static int dump_btf_type(const struct btf *btf, __u32 id,
103 const struct btf_type *t)
104{
105 json_writer_t *w = json_wtr;
106 int kind = btf_kind(t);
107
108 if (json_output) {
109 jsonw_start_object(w);
110 jsonw_uint_field(w, "id", id);
111 jsonw_string_field(w, "kind", btf_kind_str[btf_kind_safe(kind)]);
112 jsonw_string_field(w, "name", btf_str(btf, t->name_off));
113 } else {
114 printf("[%u] %s '%s'", id, btf_kind_str[btf_kind_safe(kind)],
115 btf_str(btf, t->name_off));
116 }
117
118 switch (kind) {
119 case BTF_KIND_INT: {
120 __u32 v = *(__u32 *)(t + 1);
121 const char *enc;
122
123 enc = btf_int_enc_str(BTF_INT_ENCODING(v));
124
125 if (json_output) {
126 jsonw_uint_field(w, "size", t->size);
127 jsonw_uint_field(w, "bits_offset", BTF_INT_OFFSET(v));
128 jsonw_uint_field(w, "nr_bits", BTF_INT_BITS(v));
129 jsonw_string_field(w, "encoding", enc);
130 } else {
131 printf(" size=%u bits_offset=%u nr_bits=%u encoding=%s",
132 t->size, BTF_INT_OFFSET(v), BTF_INT_BITS(v),
133 enc);
134 }
135 break;
136 }
137 case BTF_KIND_PTR:
138 case BTF_KIND_CONST:
139 case BTF_KIND_VOLATILE:
140 case BTF_KIND_RESTRICT:
141 case BTF_KIND_TYPEDEF:
142 case BTF_KIND_TYPE_TAG:
143 if (json_output)
144 jsonw_uint_field(w, "type_id", t->type);
145 else
146 printf(" type_id=%u", t->type);
147 break;
148 case BTF_KIND_ARRAY: {
149 const struct btf_array *arr = (const void *)(t + 1);
150
151 if (json_output) {
152 jsonw_uint_field(w, "type_id", arr->type);
153 jsonw_uint_field(w, "index_type_id", arr->index_type);
154 jsonw_uint_field(w, "nr_elems", arr->nelems);
155 } else {
156 printf(" type_id=%u index_type_id=%u nr_elems=%u",
157 arr->type, arr->index_type, arr->nelems);
158 }
159 break;
160 }
161 case BTF_KIND_STRUCT:
162 case BTF_KIND_UNION: {
163 const struct btf_member *m = (const void *)(t + 1);
164 __u16 vlen = BTF_INFO_VLEN(t->info);
165 int i;
166
167 if (json_output) {
168 jsonw_uint_field(w, "size", t->size);
169 jsonw_uint_field(w, "vlen", vlen);
170 jsonw_name(w, "members");
171 jsonw_start_array(w);
172 } else {
173 printf(" size=%u vlen=%u", t->size, vlen);
174 }
175 for (i = 0; i < vlen; i++, m++) {
176 const char *name = btf_str(btf, m->name_off);
177 __u32 bit_off, bit_sz;
178
179 if (BTF_INFO_KFLAG(t->info)) {
180 bit_off = BTF_MEMBER_BIT_OFFSET(m->offset);
181 bit_sz = BTF_MEMBER_BITFIELD_SIZE(m->offset);
182 } else {
183 bit_off = m->offset;
184 bit_sz = 0;
185 }
186
187 if (json_output) {
188 jsonw_start_object(w);
189 jsonw_string_field(w, "name", name);
190 jsonw_uint_field(w, "type_id", m->type);
191 jsonw_uint_field(w, "bits_offset", bit_off);
192 if (bit_sz) {
193 jsonw_uint_field(w, "bitfield_size",
194 bit_sz);
195 }
196 jsonw_end_object(w);
197 } else {
198 printf("\n\t'%s' type_id=%u bits_offset=%u",
199 name, m->type, bit_off);
200 if (bit_sz)
201 printf(" bitfield_size=%u", bit_sz);
202 }
203 }
204 if (json_output)
205 jsonw_end_array(w);
206 break;
207 }
208 case BTF_KIND_ENUM: {
209 const struct btf_enum *v = (const void *)(t + 1);
210 __u16 vlen = BTF_INFO_VLEN(t->info);
211 const char *encoding;
212 int i;
213
214 encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
215 if (json_output) {
216 jsonw_string_field(w, "encoding", encoding);
217 jsonw_uint_field(w, "size", t->size);
218 jsonw_uint_field(w, "vlen", vlen);
219 jsonw_name(w, "values");
220 jsonw_start_array(w);
221 } else {
222 printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
223 }
224 for (i = 0; i < vlen; i++, v++) {
225 const char *name = btf_str(btf, v->name_off);
226
227 if (json_output) {
228 jsonw_start_object(w);
229 jsonw_string_field(w, "name", name);
230 if (btf_kflag(t))
231 jsonw_int_field(w, "val", v->val);
232 else
233 jsonw_uint_field(w, "val", v->val);
234 jsonw_end_object(w);
235 } else {
236 if (btf_kflag(t))
237 printf("\n\t'%s' val=%d", name, v->val);
238 else
239 printf("\n\t'%s' val=%u", name, v->val);
240 }
241 }
242 if (json_output)
243 jsonw_end_array(w);
244 break;
245 }
246 case BTF_KIND_ENUM64: {
247 const struct btf_enum64 *v = btf_enum64(t);
248 __u16 vlen = btf_vlen(t);
249 const char *encoding;
250 int i;
251
252 encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
253 if (json_output) {
254 jsonw_string_field(w, "encoding", encoding);
255 jsonw_uint_field(w, "size", t->size);
256 jsonw_uint_field(w, "vlen", vlen);
257 jsonw_name(w, "values");
258 jsonw_start_array(w);
259 } else {
260 printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
261 }
262 for (i = 0; i < vlen; i++, v++) {
263 const char *name = btf_str(btf, v->name_off);
264 __u64 val = ((__u64)v->val_hi32 << 32) | v->val_lo32;
265
266 if (json_output) {
267 jsonw_start_object(w);
268 jsonw_string_field(w, "name", name);
269 if (btf_kflag(t))
270 jsonw_int_field(w, "val", val);
271 else
272 jsonw_uint_field(w, "val", val);
273 jsonw_end_object(w);
274 } else {
275 if (btf_kflag(t))
276 printf("\n\t'%s' val=%lldLL", name,
277 (unsigned long long)val);
278 else
279 printf("\n\t'%s' val=%lluULL", name,
280 (unsigned long long)val);
281 }
282 }
283 if (json_output)
284 jsonw_end_array(w);
285 break;
286 }
287 case BTF_KIND_FWD: {
288 const char *fwd_kind = BTF_INFO_KFLAG(t->info) ? "union"
289 : "struct";
290
291 if (json_output)
292 jsonw_string_field(w, "fwd_kind", fwd_kind);
293 else
294 printf(" fwd_kind=%s", fwd_kind);
295 break;
296 }
297 case BTF_KIND_FUNC: {
298 const char *linkage = btf_func_linkage_str(t);
299
300 if (json_output) {
301 jsonw_uint_field(w, "type_id", t->type);
302 jsonw_string_field(w, "linkage", linkage);
303 } else {
304 printf(" type_id=%u linkage=%s", t->type, linkage);
305 }
306 break;
307 }
308 case BTF_KIND_FUNC_PROTO: {
309 const struct btf_param *p = (const void *)(t + 1);
310 __u16 vlen = BTF_INFO_VLEN(t->info);
311 int i;
312
313 if (json_output) {
314 jsonw_uint_field(w, "ret_type_id", t->type);
315 jsonw_uint_field(w, "vlen", vlen);
316 jsonw_name(w, "params");
317 jsonw_start_array(w);
318 } else {
319 printf(" ret_type_id=%u vlen=%u", t->type, vlen);
320 }
321 for (i = 0; i < vlen; i++, p++) {
322 const char *name = btf_str(btf, p->name_off);
323
324 if (json_output) {
325 jsonw_start_object(w);
326 jsonw_string_field(w, "name", name);
327 jsonw_uint_field(w, "type_id", p->type);
328 jsonw_end_object(w);
329 } else {
330 printf("\n\t'%s' type_id=%u", name, p->type);
331 }
332 }
333 if (json_output)
334 jsonw_end_array(w);
335 break;
336 }
337 case BTF_KIND_VAR: {
338 const struct btf_var *v = (const void *)(t + 1);
339 const char *linkage;
340
341 linkage = btf_var_linkage_str(v->linkage);
342
343 if (json_output) {
344 jsonw_uint_field(w, "type_id", t->type);
345 jsonw_string_field(w, "linkage", linkage);
346 } else {
347 printf(" type_id=%u, linkage=%s", t->type, linkage);
348 }
349 break;
350 }
351 case BTF_KIND_DATASEC: {
352 const struct btf_var_secinfo *v = (const void *)(t + 1);
353 const struct btf_type *vt;
354 __u16 vlen = BTF_INFO_VLEN(t->info);
355 int i;
356
357 if (json_output) {
358 jsonw_uint_field(w, "size", t->size);
359 jsonw_uint_field(w, "vlen", vlen);
360 jsonw_name(w, "vars");
361 jsonw_start_array(w);
362 } else {
363 printf(" size=%u vlen=%u", t->size, vlen);
364 }
365 for (i = 0; i < vlen; i++, v++) {
366 if (json_output) {
367 jsonw_start_object(w);
368 jsonw_uint_field(w, "type_id", v->type);
369 jsonw_uint_field(w, "offset", v->offset);
370 jsonw_uint_field(w, "size", v->size);
371 jsonw_end_object(w);
372 } else {
373 printf("\n\ttype_id=%u offset=%u size=%u",
374 v->type, v->offset, v->size);
375
376 if (v->type < btf__type_cnt(btf)) {
377 vt = btf__type_by_id(btf, v->type);
378 printf(" (%s '%s')",
379 btf_kind_str[btf_kind_safe(btf_kind(vt))],
380 btf_str(btf, vt->name_off));
381 }
382 }
383 }
384 if (json_output)
385 jsonw_end_array(w);
386 break;
387 }
388 case BTF_KIND_FLOAT: {
389 if (json_output)
390 jsonw_uint_field(w, "size", t->size);
391 else
392 printf(" size=%u", t->size);
393 break;
394 }
395 case BTF_KIND_DECL_TAG: {
396 const struct btf_decl_tag *tag = (const void *)(t + 1);
397
398 if (json_output) {
399 jsonw_uint_field(w, "type_id", t->type);
400 jsonw_int_field(w, "component_idx", tag->component_idx);
401 } else {
402 printf(" type_id=%u component_idx=%d", t->type, tag->component_idx);
403 }
404 break;
405 }
406 default:
407 break;
408 }
409
410 if (json_output)
411 jsonw_end_object(json_wtr);
412 else
413 printf("\n");
414
415 return 0;
416}
417
418static int dump_btf_raw(const struct btf *btf,
419 __u32 *root_type_ids, int root_type_cnt)
420{
421 const struct btf_type *t;
422 int i;
423
424 if (json_output) {
425 jsonw_start_object(json_wtr);
426 jsonw_name(json_wtr, "types");
427 jsonw_start_array(json_wtr);
428 }
429
430 if (root_type_cnt) {
431 for (i = 0; i < root_type_cnt; i++) {
432 t = btf__type_by_id(btf, root_type_ids[i]);
433 dump_btf_type(btf, root_type_ids[i], t);
434 }
435 } else {
436 const struct btf *base;
437 int cnt = btf__type_cnt(btf);
438 int start_id = 1;
439
440 base = btf__base_btf(btf);
441 if (base)
442 start_id = btf__type_cnt(base);
443
444 for (i = start_id; i < cnt; i++) {
445 t = btf__type_by_id(btf, i);
446 dump_btf_type(btf, i, t);
447 }
448 }
449
450 if (json_output) {
451 jsonw_end_array(json_wtr);
452 jsonw_end_object(json_wtr);
453 }
454 return 0;
455}
456
457static void __printf(2, 0) btf_dump_printf(void *ctx,
458 const char *fmt, va_list args)
459{
460 vfprintf(stdout, fmt, args);
461}
462
463static int dump_btf_c(const struct btf *btf,
464 __u32 *root_type_ids, int root_type_cnt)
465{
466 struct btf_dump *d;
467 int err = 0, i;
468
469 d = btf_dump__new(btf, btf_dump_printf, NULL, NULL);
470 if (!d)
471 return -errno;
472
473 printf("#ifndef __VMLINUX_H__\n");
474 printf("#define __VMLINUX_H__\n");
475 printf("\n");
476 printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
477 printf("#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)\n");
478 printf("#endif\n\n");
479
480 if (root_type_cnt) {
481 for (i = 0; i < root_type_cnt; i++) {
482 err = btf_dump__dump_type(d, root_type_ids[i]);
483 if (err)
484 goto done;
485 }
486 } else {
487 int cnt = btf__type_cnt(btf);
488
489 for (i = 1; i < cnt; i++) {
490 err = btf_dump__dump_type(d, i);
491 if (err)
492 goto done;
493 }
494 }
495
496 printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
497 printf("#pragma clang attribute pop\n");
498 printf("#endif\n");
499 printf("\n");
500 printf("#endif /* __VMLINUX_H__ */\n");
501
502done:
503 btf_dump__free(d);
504 return err;
505}
506
507static const char sysfs_vmlinux[] = "/sys/kernel/btf/vmlinux";
508
509static struct btf *get_vmlinux_btf_from_sysfs(void)
510{
511 struct btf *base;
512
513 base = btf__parse(sysfs_vmlinux, NULL);
514 if (!base)
515 p_err("failed to parse vmlinux BTF at '%s': %d\n",
516 sysfs_vmlinux, -errno);
517
518 return base;
519}
520
521#define BTF_NAME_BUFF_LEN 64
522
523static bool btf_is_kernel_module(__u32 btf_id)
524{
525 struct bpf_btf_info btf_info = {};
526 char btf_name[BTF_NAME_BUFF_LEN];
527 int btf_fd;
528 __u32 len;
529 int err;
530
531 btf_fd = bpf_btf_get_fd_by_id(btf_id);
532 if (btf_fd < 0) {
533 p_err("can't get BTF object by id (%u): %s", btf_id, strerror(errno));
534 return false;
535 }
536
537 len = sizeof(btf_info);
538 btf_info.name = ptr_to_u64(btf_name);
539 btf_info.name_len = sizeof(btf_name);
540 err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
541 close(btf_fd);
542 if (err) {
543 p_err("can't get BTF (ID %u) object info: %s", btf_id, strerror(errno));
544 return false;
545 }
546
547 return btf_info.kernel_btf && strncmp(btf_name, "vmlinux", sizeof(btf_name)) != 0;
548}
549
550static int do_dump(int argc, char **argv)
551{
552 struct btf *btf = NULL, *base = NULL;
553 __u32 root_type_ids[2];
554 int root_type_cnt = 0;
555 bool dump_c = false;
556 __u32 btf_id = -1;
557 const char *src;
558 int fd = -1;
559 int err = 0;
560
561 if (!REQ_ARGS(2)) {
562 usage();
563 return -1;
564 }
565 src = GET_ARG();
566 if (is_prefix(src, "map")) {
567 struct bpf_map_info info = {};
568 __u32 len = sizeof(info);
569
570 if (!REQ_ARGS(2)) {
571 usage();
572 return -1;
573 }
574
575 fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
576 if (fd < 0)
577 return -1;
578
579 btf_id = info.btf_id;
580 if (argc && is_prefix(*argv, "key")) {
581 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
582 NEXT_ARG();
583 } else if (argc && is_prefix(*argv, "value")) {
584 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
585 NEXT_ARG();
586 } else if (argc && is_prefix(*argv, "all")) {
587 NEXT_ARG();
588 } else if (argc && is_prefix(*argv, "kv")) {
589 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
590 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
591 NEXT_ARG();
592 } else {
593 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
594 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
595 }
596 } else if (is_prefix(src, "prog")) {
597 struct bpf_prog_info info = {};
598 __u32 len = sizeof(info);
599
600 if (!REQ_ARGS(2)) {
601 usage();
602 return -1;
603 }
604
605 fd = prog_parse_fd(&argc, &argv);
606 if (fd < 0)
607 return -1;
608
609 err = bpf_obj_get_info_by_fd(fd, &info, &len);
610 if (err) {
611 p_err("can't get prog info: %s", strerror(errno));
612 goto done;
613 }
614
615 btf_id = info.btf_id;
616 } else if (is_prefix(src, "id")) {
617 char *endptr;
618
619 btf_id = strtoul(*argv, &endptr, 0);
620 if (*endptr) {
621 p_err("can't parse %s as ID", *argv);
622 return -1;
623 }
624 NEXT_ARG();
625 } else if (is_prefix(src, "file")) {
626 const char sysfs_prefix[] = "/sys/kernel/btf/";
627
628 if (!base_btf &&
629 strncmp(*argv, sysfs_prefix, sizeof(sysfs_prefix) - 1) == 0 &&
630 strcmp(*argv, sysfs_vmlinux) != 0)
631 base = get_vmlinux_btf_from_sysfs();
632
633 btf = btf__parse_split(*argv, base ?: base_btf);
634 if (!btf) {
635 err = -errno;
636 p_err("failed to load BTF from %s: %s",
637 *argv, strerror(errno));
638 goto done;
639 }
640 NEXT_ARG();
641 } else {
642 err = -1;
643 p_err("unrecognized BTF source specifier: '%s'", src);
644 goto done;
645 }
646
647 while (argc) {
648 if (is_prefix(*argv, "format")) {
649 NEXT_ARG();
650 if (argc < 1) {
651 p_err("expecting value for 'format' option\n");
652 err = -EINVAL;
653 goto done;
654 }
655 if (strcmp(*argv, "c") == 0) {
656 dump_c = true;
657 } else if (strcmp(*argv, "raw") == 0) {
658 dump_c = false;
659 } else {
660 p_err("unrecognized format specifier: '%s', possible values: raw, c",
661 *argv);
662 err = -EINVAL;
663 goto done;
664 }
665 NEXT_ARG();
666 } else {
667 p_err("unrecognized option: '%s'", *argv);
668 err = -EINVAL;
669 goto done;
670 }
671 }
672
673 if (!btf) {
674 if (!base_btf && btf_is_kernel_module(btf_id)) {
675 p_info("Warning: valid base BTF was not specified with -B option, falling back to standard base BTF (%s)",
676 sysfs_vmlinux);
677 base_btf = get_vmlinux_btf_from_sysfs();
678 }
679
680 btf = btf__load_from_kernel_by_id_split(btf_id, base_btf);
681 if (!btf) {
682 err = -errno;
683 p_err("get btf by id (%u): %s", btf_id, strerror(errno));
684 goto done;
685 }
686 }
687
688 if (dump_c) {
689 if (json_output) {
690 p_err("JSON output for C-syntax dump is not supported");
691 err = -ENOTSUP;
692 goto done;
693 }
694 err = dump_btf_c(btf, root_type_ids, root_type_cnt);
695 } else {
696 err = dump_btf_raw(btf, root_type_ids, root_type_cnt);
697 }
698
699done:
700 close(fd);
701 btf__free(btf);
702 btf__free(base);
703 return err;
704}
705
706static int btf_parse_fd(int *argc, char ***argv)
707{
708 unsigned int id;
709 char *endptr;
710 int fd;
711
712 if (!is_prefix(*argv[0], "id")) {
713 p_err("expected 'id', got: '%s'?", **argv);
714 return -1;
715 }
716 NEXT_ARGP();
717
718 id = strtoul(**argv, &endptr, 0);
719 if (*endptr) {
720 p_err("can't parse %s as ID", **argv);
721 return -1;
722 }
723 NEXT_ARGP();
724
725 fd = bpf_btf_get_fd_by_id(id);
726 if (fd < 0)
727 p_err("can't get BTF object by id (%u): %s",
728 id, strerror(errno));
729
730 return fd;
731}
732
733static int
734build_btf_type_table(struct hashmap *tab, enum bpf_obj_type type,
735 void *info, __u32 *len)
736{
737 static const char * const names[] = {
738 [BPF_OBJ_UNKNOWN] = "unknown",
739 [BPF_OBJ_PROG] = "prog",
740 [BPF_OBJ_MAP] = "map",
741 };
742 __u32 btf_id, id = 0;
743 int err;
744 int fd;
745
746 while (true) {
747 switch (type) {
748 case BPF_OBJ_PROG:
749 err = bpf_prog_get_next_id(id, &id);
750 break;
751 case BPF_OBJ_MAP:
752 err = bpf_map_get_next_id(id, &id);
753 break;
754 default:
755 err = -1;
756 p_err("unexpected object type: %d", type);
757 goto err_free;
758 }
759 if (err) {
760 if (errno == ENOENT) {
761 err = 0;
762 break;
763 }
764 p_err("can't get next %s: %s%s", names[type],
765 strerror(errno),
766 errno == EINVAL ? " -- kernel too old?" : "");
767 goto err_free;
768 }
769
770 switch (type) {
771 case BPF_OBJ_PROG:
772 fd = bpf_prog_get_fd_by_id(id);
773 break;
774 case BPF_OBJ_MAP:
775 fd = bpf_map_get_fd_by_id(id);
776 break;
777 default:
778 err = -1;
779 p_err("unexpected object type: %d", type);
780 goto err_free;
781 }
782 if (fd < 0) {
783 if (errno == ENOENT)
784 continue;
785 p_err("can't get %s by id (%u): %s", names[type], id,
786 strerror(errno));
787 err = -1;
788 goto err_free;
789 }
790
791 memset(info, 0, *len);
792 err = bpf_obj_get_info_by_fd(fd, info, len);
793 close(fd);
794 if (err) {
795 p_err("can't get %s info: %s", names[type],
796 strerror(errno));
797 goto err_free;
798 }
799
800 switch (type) {
801 case BPF_OBJ_PROG:
802 btf_id = ((struct bpf_prog_info *)info)->btf_id;
803 break;
804 case BPF_OBJ_MAP:
805 btf_id = ((struct bpf_map_info *)info)->btf_id;
806 break;
807 default:
808 err = -1;
809 p_err("unexpected object type: %d", type);
810 goto err_free;
811 }
812 if (!btf_id)
813 continue;
814
815 err = hashmap__append(tab, btf_id, id);
816 if (err) {
817 p_err("failed to append entry to hashmap for BTF ID %u, object ID %u: %s",
818 btf_id, id, strerror(-err));
819 goto err_free;
820 }
821 }
822
823 return 0;
824
825err_free:
826 hashmap__free(tab);
827 return err;
828}
829
830static int
831build_btf_tables(struct hashmap *btf_prog_table,
832 struct hashmap *btf_map_table)
833{
834 struct bpf_prog_info prog_info;
835 __u32 prog_len = sizeof(prog_info);
836 struct bpf_map_info map_info;
837 __u32 map_len = sizeof(map_info);
838 int err = 0;
839
840 err = build_btf_type_table(btf_prog_table, BPF_OBJ_PROG, &prog_info,
841 &prog_len);
842 if (err)
843 return err;
844
845 err = build_btf_type_table(btf_map_table, BPF_OBJ_MAP, &map_info,
846 &map_len);
847 if (err) {
848 hashmap__free(btf_prog_table);
849 return err;
850 }
851
852 return 0;
853}
854
855static void
856show_btf_plain(struct bpf_btf_info *info, int fd,
857 struct hashmap *btf_prog_table,
858 struct hashmap *btf_map_table)
859{
860 struct hashmap_entry *entry;
861 const char *name = u64_to_ptr(info->name);
862 int n;
863
864 printf("%u: ", info->id);
865 if (info->kernel_btf)
866 printf("name [%s] ", name);
867 else if (name && name[0])
868 printf("name %s ", name);
869 else
870 printf("name <anon> ");
871 printf("size %uB", info->btf_size);
872
873 n = 0;
874 hashmap__for_each_key_entry(btf_prog_table, entry, info->id) {
875 printf("%s%lu", n++ == 0 ? " prog_ids " : ",", entry->value);
876 }
877
878 n = 0;
879 hashmap__for_each_key_entry(btf_map_table, entry, info->id) {
880 printf("%s%lu", n++ == 0 ? " map_ids " : ",", entry->value);
881 }
882
883 emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
884
885 printf("\n");
886}
887
888static void
889show_btf_json(struct bpf_btf_info *info, int fd,
890 struct hashmap *btf_prog_table,
891 struct hashmap *btf_map_table)
892{
893 struct hashmap_entry *entry;
894 const char *name = u64_to_ptr(info->name);
895
896 jsonw_start_object(json_wtr); /* btf object */
897 jsonw_uint_field(json_wtr, "id", info->id);
898 jsonw_uint_field(json_wtr, "size", info->btf_size);
899
900 jsonw_name(json_wtr, "prog_ids");
901 jsonw_start_array(json_wtr); /* prog_ids */
902 hashmap__for_each_key_entry(btf_prog_table, entry, info->id) {
903 jsonw_uint(json_wtr, entry->value);
904 }
905 jsonw_end_array(json_wtr); /* prog_ids */
906
907 jsonw_name(json_wtr, "map_ids");
908 jsonw_start_array(json_wtr); /* map_ids */
909 hashmap__for_each_key_entry(btf_map_table, entry, info->id) {
910 jsonw_uint(json_wtr, entry->value);
911 }
912 jsonw_end_array(json_wtr); /* map_ids */
913
914 emit_obj_refs_json(refs_table, info->id, json_wtr); /* pids */
915
916 jsonw_bool_field(json_wtr, "kernel", info->kernel_btf);
917
918 if (name && name[0])
919 jsonw_string_field(json_wtr, "name", name);
920
921 jsonw_end_object(json_wtr); /* btf object */
922}
923
924static int
925show_btf(int fd, struct hashmap *btf_prog_table,
926 struct hashmap *btf_map_table)
927{
928 struct bpf_btf_info info;
929 __u32 len = sizeof(info);
930 char name[64];
931 int err;
932
933 memset(&info, 0, sizeof(info));
934 err = bpf_obj_get_info_by_fd(fd, &info, &len);
935 if (err) {
936 p_err("can't get BTF object info: %s", strerror(errno));
937 return -1;
938 }
939 /* if kernel support emitting BTF object name, pass name pointer */
940 if (info.name_len) {
941 memset(&info, 0, sizeof(info));
942 info.name_len = sizeof(name);
943 info.name = ptr_to_u64(name);
944 len = sizeof(info);
945
946 err = bpf_obj_get_info_by_fd(fd, &info, &len);
947 if (err) {
948 p_err("can't get BTF object info: %s", strerror(errno));
949 return -1;
950 }
951 }
952
953 if (json_output)
954 show_btf_json(&info, fd, btf_prog_table, btf_map_table);
955 else
956 show_btf_plain(&info, fd, btf_prog_table, btf_map_table);
957
958 return 0;
959}
960
961static int do_show(int argc, char **argv)
962{
963 struct hashmap *btf_prog_table;
964 struct hashmap *btf_map_table;
965 int err, fd = -1;
966 __u32 id = 0;
967
968 if (argc == 2) {
969 fd = btf_parse_fd(&argc, &argv);
970 if (fd < 0)
971 return -1;
972 }
973
974 if (argc) {
975 if (fd >= 0)
976 close(fd);
977 return BAD_ARG();
978 }
979
980 btf_prog_table = hashmap__new(hash_fn_for_key_as_id,
981 equal_fn_for_key_as_id, NULL);
982 btf_map_table = hashmap__new(hash_fn_for_key_as_id,
983 equal_fn_for_key_as_id, NULL);
984 if (IS_ERR(btf_prog_table) || IS_ERR(btf_map_table)) {
985 hashmap__free(btf_prog_table);
986 hashmap__free(btf_map_table);
987 if (fd >= 0)
988 close(fd);
989 p_err("failed to create hashmap for object references");
990 return -1;
991 }
992 err = build_btf_tables(btf_prog_table, btf_map_table);
993 if (err) {
994 if (fd >= 0)
995 close(fd);
996 return err;
997 }
998 build_obj_refs_table(&refs_table, BPF_OBJ_BTF);
999
1000 if (fd >= 0) {
1001 err = show_btf(fd, btf_prog_table, btf_map_table);
1002 close(fd);
1003 goto exit_free;
1004 }
1005
1006 if (json_output)
1007 jsonw_start_array(json_wtr); /* root array */
1008
1009 while (true) {
1010 err = bpf_btf_get_next_id(id, &id);
1011 if (err) {
1012 if (errno == ENOENT) {
1013 err = 0;
1014 break;
1015 }
1016 p_err("can't get next BTF object: %s%s",
1017 strerror(errno),
1018 errno == EINVAL ? " -- kernel too old?" : "");
1019 err = -1;
1020 break;
1021 }
1022
1023 fd = bpf_btf_get_fd_by_id(id);
1024 if (fd < 0) {
1025 if (errno == ENOENT)
1026 continue;
1027 p_err("can't get BTF object by id (%u): %s",
1028 id, strerror(errno));
1029 err = -1;
1030 break;
1031 }
1032
1033 err = show_btf(fd, btf_prog_table, btf_map_table);
1034 close(fd);
1035 if (err)
1036 break;
1037 }
1038
1039 if (json_output)
1040 jsonw_end_array(json_wtr); /* root array */
1041
1042exit_free:
1043 hashmap__free(btf_prog_table);
1044 hashmap__free(btf_map_table);
1045 delete_obj_refs_table(refs_table);
1046
1047 return err;
1048}
1049
1050static int do_help(int argc, char **argv)
1051{
1052 if (json_output) {
1053 jsonw_null(json_wtr);
1054 return 0;
1055 }
1056
1057 fprintf(stderr,
1058 "Usage: %1$s %2$s { show | list } [id BTF_ID]\n"
1059 " %1$s %2$s dump BTF_SRC [format FORMAT]\n"
1060 " %1$s %2$s help\n"
1061 "\n"
1062 " BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }\n"
1063 " FORMAT := { raw | c }\n"
1064 " " HELP_SPEC_MAP "\n"
1065 " " HELP_SPEC_PROGRAM "\n"
1066 " " HELP_SPEC_OPTIONS " |\n"
1067 " {-B|--base-btf} }\n"
1068 "",
1069 bin_name, "btf");
1070
1071 return 0;
1072}
1073
1074static const struct cmd cmds[] = {
1075 { "show", do_show },
1076 { "list", do_show },
1077 { "help", do_help },
1078 { "dump", do_dump },
1079 { 0 }
1080};
1081
1082int do_btf(int argc, char **argv)
1083{
1084 return cmd_select(cmds, argc, argv, do_help);
1085}