?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / tools / bpf / bpftool / btf.c
blobb3745ed711baa06276102def979cae3750b0ec3a
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 <bpf/bpf.h>
12 #include <bpf/btf.h>
13 #include <bpf/libbpf.h>
14 #include <linux/btf.h>
15 #include <linux/hashtable.h>
16 #include <sys/types.h>
17 #include <sys/stat.h>
18 #include <unistd.h>
19
20 #include "json_writer.h"
21 #include "main.h"
22
23 static 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 };
41
42 struct btf_attach_table {
43 DECLARE_HASHTABLE(table, 16);
44 };
45
46 struct btf_attach_point {
47 __u32 obj_id;
48 __u32 btf_id;
49 struct hlist_node hash;
50 };
51
52 static const char *btf_int_enc_str(__u8 encoding)
53 {
54 switch (encoding) {
55 case 0:
56 return "(none)";
57 case BTF_INT_SIGNED:
58 return "SIGNED";
59 case BTF_INT_CHAR:
60 return "CHAR";
61 case BTF_INT_BOOL:
62 return "BOOL";
63 default:
64 return "UNKN";
65 }
66 }
67
68 static const char *btf_var_linkage_str(__u32 linkage)
69 {
70 switch (linkage) {
71 case BTF_VAR_STATIC:
72 return "static";
73 case BTF_VAR_GLOBAL_ALLOCATED:
74 return "global-alloc";
75 default:
76 return "(unknown)";
77 }
78 }
79
80 static const char *btf_func_linkage_str(const struct btf_type *t)
81 {
82 switch (btf_vlen(t)) {
83 case BTF_FUNC_STATIC:
84 return "static";
85 case BTF_FUNC_GLOBAL:
86 return "global";
87 case BTF_FUNC_EXTERN:
88 return "extern";
89 default:
90 return "(unknown)";
91 }
92 }
93
94 static const char *btf_str(const struct btf *btf, __u32 off)
95 {
96 if (!off)
97 return "(anon)";
98 return btf__name_by_offset(btf, off) ? : "(invalid)";
99 }
100
101 static int dump_btf_type(const struct btf *btf, __u32 id,
102 const struct btf_type *t)
103 {
104 json_writer_t *w = json_wtr;
105 int kind, safe_kind;
106
107 kind = BTF_INFO_KIND(t->info);
108 safe_kind = kind <= BTF_KIND_MAX ? kind : BTF_KIND_UNKN;
109
110 if (json_output) {
111 jsonw_start_object(w);
112 jsonw_uint_field(w, "id", id);
113 jsonw_string_field(w, "kind", btf_kind_str[safe_kind]);
114 jsonw_string_field(w, "name", btf_str(btf, t->name_off));
115 } else {
116 printf("[%u] %s '%s'", id, btf_kind_str[safe_kind],
117 btf_str(btf, t->name_off));
118 }
119
120 switch (BTF_INFO_KIND(t->info)) {
121 case BTF_KIND_INT: {
122 __u32 v = *(__u32 *)(t + 1);
123 const char *enc;
124
125 enc = btf_int_enc_str(BTF_INT_ENCODING(v));
126
127 if (json_output) {
128 jsonw_uint_field(w, "size", t->size);
129 jsonw_uint_field(w, "bits_offset", BTF_INT_OFFSET(v));
130 jsonw_uint_field(w, "nr_bits", BTF_INT_BITS(v));
131 jsonw_string_field(w, "encoding", enc);
132 } else {
133 printf(" size=%u bits_offset=%u nr_bits=%u encoding=%s",
134 t->size, BTF_INT_OFFSET(v), BTF_INT_BITS(v),
135 enc);
136 }
137 break;
138 }
139 case BTF_KIND_PTR:
140 case BTF_KIND_CONST:
141 case BTF_KIND_VOLATILE:
142 case BTF_KIND_RESTRICT:
143 case BTF_KIND_TYPEDEF:
144 if (json_output)
145 jsonw_uint_field(w, "type_id", t->type);
146 else
147 printf(" type_id=%u", t->type);
148 break;
149 case BTF_KIND_ARRAY: {
150 const struct btf_array *arr = (const void *)(t + 1);
151
152 if (json_output) {
153 jsonw_uint_field(w, "type_id", arr->type);
154 jsonw_uint_field(w, "index_type_id", arr->index_type);
155 jsonw_uint_field(w, "nr_elems", arr->nelems);
156 } else {
157 printf(" type_id=%u index_type_id=%u nr_elems=%u",
158 arr->type, arr->index_type, arr->nelems);
159 }
160 break;
161 }
162 case BTF_KIND_STRUCT:
163 case BTF_KIND_UNION: {
164 const struct btf_member *m = (const void *)(t + 1);
165 __u16 vlen = BTF_INFO_VLEN(t->info);
166 int i;
167
168 if (json_output) {
169 jsonw_uint_field(w, "size", t->size);
170 jsonw_uint_field(w, "vlen", vlen);
171 jsonw_name(w, "members");
172 jsonw_start_array(w);
173 } else {
174 printf(" size=%u vlen=%u", t->size, vlen);
175 }
176 for (i = 0; i < vlen; i++, m++) {
177 const char *name = btf_str(btf, m->name_off);
178 __u32 bit_off, bit_sz;
179
180 if (BTF_INFO_KFLAG(t->info)) {
181 bit_off = BTF_MEMBER_BIT_OFFSET(m->offset);
182 bit_sz = BTF_MEMBER_BITFIELD_SIZE(m->offset);
183 } else {
184 bit_off = m->offset;
185 bit_sz = 0;
186 }
187
188 if (json_output) {
189 jsonw_start_object(w);
190 jsonw_string_field(w, "name", name);
191 jsonw_uint_field(w, "type_id", m->type);
192 jsonw_uint_field(w, "bits_offset", bit_off);
193 if (bit_sz) {
194 jsonw_uint_field(w, "bitfield_size",
195 bit_sz);
196 }
197 jsonw_end_object(w);
198 } else {
199 printf("\n\t'%s' type_id=%u bits_offset=%u",
200 name, m->type, bit_off);
201 if (bit_sz)
202 printf(" bitfield_size=%u", bit_sz);
203 }
204 }
205 if (json_output)
206 jsonw_end_array(w);
207 break;
208 }
209 case BTF_KIND_ENUM: {
210 const struct btf_enum *v = (const void *)(t + 1);
211 __u16 vlen = BTF_INFO_VLEN(t->info);
212 int i;
213
214 if (json_output) {
215 jsonw_uint_field(w, "size", t->size);
216 jsonw_uint_field(w, "vlen", vlen);
217 jsonw_name(w, "values");
218 jsonw_start_array(w);
219 } else {
220 printf(" size=%u vlen=%u", t->size, vlen);
221 }
222 for (i = 0; i < vlen; i++, v++) {
223 const char *name = btf_str(btf, v->name_off);
224
225 if (json_output) {
226 jsonw_start_object(w);
227 jsonw_string_field(w, "name", name);
228 jsonw_uint_field(w, "val", v->val);
229 jsonw_end_object(w);
230 } else {
231 printf("\n\t'%s' val=%u", name, v->val);
232 }
233 }
234 if (json_output)
235 jsonw_end_array(w);
236 break;
237 }
238 case BTF_KIND_FWD: {
239 const char *fwd_kind = BTF_INFO_KFLAG(t->info) ? "union"
240 : "struct";
241
242 if (json_output)
243 jsonw_string_field(w, "fwd_kind", fwd_kind);
244 else
245 printf(" fwd_kind=%s", fwd_kind);
246 break;
247 }
248 case BTF_KIND_FUNC: {
249 const char *linkage = btf_func_linkage_str(t);
250
251 if (json_output) {
252 jsonw_uint_field(w, "type_id", t->type);
253 jsonw_string_field(w, "linkage", linkage);
254 } else {
255 printf(" type_id=%u linkage=%s", t->type, linkage);
256 }
257 break;
258 }
259 case BTF_KIND_FUNC_PROTO: {
260 const struct btf_param *p = (const void *)(t + 1);
261 __u16 vlen = BTF_INFO_VLEN(t->info);
262 int i;
263
264 if (json_output) {
265 jsonw_uint_field(w, "ret_type_id", t->type);
266 jsonw_uint_field(w, "vlen", vlen);
267 jsonw_name(w, "params");
268 jsonw_start_array(w);
269 } else {
270 printf(" ret_type_id=%u vlen=%u", t->type, vlen);
271 }
272 for (i = 0; i < vlen; i++, p++) {
273 const char *name = btf_str(btf, p->name_off);
274
275 if (json_output) {
276 jsonw_start_object(w);
277 jsonw_string_field(w, "name", name);
278 jsonw_uint_field(w, "type_id", p->type);
279 jsonw_end_object(w);
280 } else {
281 printf("\n\t'%s' type_id=%u", name, p->type);
282 }
283 }
284 if (json_output)
285 jsonw_end_array(w);
286 break;
287 }
288 case BTF_KIND_VAR: {
289 const struct btf_var *v = (const void *)(t + 1);
290 const char *linkage;
291
292 linkage = btf_var_linkage_str(v->linkage);
293
294 if (json_output) {
295 jsonw_uint_field(w, "type_id", t->type);
296 jsonw_string_field(w, "linkage", linkage);
297 } else {
298 printf(" type_id=%u, linkage=%s", t->type, linkage);
299 }
300 break;
301 }
302 case BTF_KIND_DATASEC: {
303 const struct btf_var_secinfo *v = (const void *)(t+1);
304 __u16 vlen = BTF_INFO_VLEN(t->info);
305 int i;
306
307 if (json_output) {
308 jsonw_uint_field(w, "size", t->size);
309 jsonw_uint_field(w, "vlen", vlen);
310 jsonw_name(w, "vars");
311 jsonw_start_array(w);
312 } else {
313 printf(" size=%u vlen=%u", t->size, vlen);
314 }
315 for (i = 0; i < vlen; i++, v++) {
316 if (json_output) {
317 jsonw_start_object(w);
318 jsonw_uint_field(w, "type_id", v->type);
319 jsonw_uint_field(w, "offset", v->offset);
320 jsonw_uint_field(w, "size", v->size);
321 jsonw_end_object(w);
322 } else {
323 printf("\n\ttype_id=%u offset=%u size=%u",
324 v->type, v->offset, v->size);
325 }
326 }
327 if (json_output)
328 jsonw_end_array(w);
329 break;
330 }
331 default:
332 break;
333 }
334
335 if (json_output)
336 jsonw_end_object(json_wtr);
337 else
338 printf("\n");
339
340 return 0;
341 }
342
343 static int dump_btf_raw(const struct btf *btf,
344 __u32 *root_type_ids, int root_type_cnt)
345 {
346 const struct btf_type *t;
347 int i;
348
349 if (json_output) {
350 jsonw_start_object(json_wtr);
351 jsonw_name(json_wtr, "types");
352 jsonw_start_array(json_wtr);
353 }
354
355 if (root_type_cnt) {
356 for (i = 0; i < root_type_cnt; i++) {
357 t = btf__type_by_id(btf, root_type_ids[i]);
358 dump_btf_type(btf, root_type_ids[i], t);
359 }
360 } else {
361 int cnt = btf__get_nr_types(btf);
362
363 for (i = 1; i <= cnt; i++) {
364 t = btf__type_by_id(btf, i);
365 dump_btf_type(btf, i, t);
366 }
367 }
368
369 if (json_output) {
370 jsonw_end_array(json_wtr);
371 jsonw_end_object(json_wtr);
372 }
373 return 0;
374 }
375
376 static void __printf(2, 0) btf_dump_printf(void *ctx,
377 const char *fmt, va_list args)
378 {
379 vfprintf(stdout, fmt, args);
380 }
381
382 static int dump_btf_c(const struct btf *btf,
383 __u32 *root_type_ids, int root_type_cnt)
384 {
385 struct btf_dump *d;
386 int err = 0, i;
387
388 d = btf_dump__new(btf, NULL, NULL, btf_dump_printf);
389 if (IS_ERR(d))
390 return PTR_ERR(d);
391
392 printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
393 printf("#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)\n");
394 printf("#endif\n\n");
395
396 if (root_type_cnt) {
397 for (i = 0; i < root_type_cnt; i++) {
398 err = btf_dump__dump_type(d, root_type_ids[i]);
399 if (err)
400 goto done;
401 }
402 } else {
403 int cnt = btf__get_nr_types(btf);
404
405 for (i = 1; i <= cnt; i++) {
406 err = btf_dump__dump_type(d, i);
407 if (err)
408 goto done;
409 }
410 }
411
412 printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
413 printf("#pragma clang attribute pop\n");
414 printf("#endif\n");
415
416 done:
417 btf_dump__free(d);
418 return err;
419 }
420
421 static struct btf *btf__parse_raw(const char *file)
422 {
423 struct btf *btf;
424 struct stat st;
425 __u8 *buf;
426 FILE *f;
427
428 if (stat(file, &st))
429 return NULL;
430
431 f = fopen(file, "rb");
432 if (!f)
433 return NULL;
434
435 buf = malloc(st.st_size);
436 if (!buf) {
437 btf = ERR_PTR(-ENOMEM);
438 goto exit_close;
439 }
440
441 if ((size_t) st.st_size != fread(buf, 1, st.st_size, f)) {
442 btf = ERR_PTR(-EINVAL);
443 goto exit_free;
444 }
445
446 btf = btf__new(buf, st.st_size);
447
448 exit_free:
449 free(buf);
450 exit_close:
451 fclose(f);
452 return btf;
453 }
454
455 static bool is_btf_raw(const char *file)
456 {
457 __u16 magic = 0;
458 int fd, nb_read;
459
460 fd = open(file, O_RDONLY);
461 if (fd < 0)
462 return false;
463
464 nb_read = read(fd, &magic, sizeof(magic));
465 close(fd);
466 return nb_read == sizeof(magic) && magic == BTF_MAGIC;
467 }
468
469 static int do_dump(int argc, char **argv)
470 {
471 struct btf *btf = NULL;
472 __u32 root_type_ids[2];
473 int root_type_cnt = 0;
474 bool dump_c = false;
475 __u32 btf_id = -1;
476 const char *src;
477 int fd = -1;
478 int err;
479
480 if (!REQ_ARGS(2)) {
481 usage();
482 return -1;
483 }
484 src = GET_ARG();
485
486 if (is_prefix(src, "map")) {
487 struct bpf_map_info info = {};
488 __u32 len = sizeof(info);
489
490 if (!REQ_ARGS(2)) {
491 usage();
492 return -1;
493 }
494
495 fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
496 if (fd < 0)
497 return -1;
498
499 btf_id = info.btf_id;
500 if (argc && is_prefix(*argv, "key")) {
501 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
502 NEXT_ARG();
503 } else if (argc && is_prefix(*argv, "value")) {
504 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
505 NEXT_ARG();
506 } else if (argc && is_prefix(*argv, "all")) {
507 NEXT_ARG();
508 } else if (argc && is_prefix(*argv, "kv")) {
509 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
510 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
511 NEXT_ARG();
512 } else {
513 root_type_ids[root_type_cnt++] = info.btf_key_type_id;
514 root_type_ids[root_type_cnt++] = info.btf_value_type_id;
515 }
516 } else if (is_prefix(src, "prog")) {
517 struct bpf_prog_info info = {};
518 __u32 len = sizeof(info);
519
520 if (!REQ_ARGS(2)) {
521 usage();
522 return -1;
523 }
524
525 fd = prog_parse_fd(&argc, &argv);
526 if (fd < 0)
527 return -1;
528
529 err = bpf_obj_get_info_by_fd(fd, &info, &len);
530 if (err) {
531 p_err("can't get prog info: %s", strerror(errno));
532 goto done;
533 }
534
535 btf_id = info.btf_id;
536 } else if (is_prefix(src, "id")) {
537 char *endptr;
538
539 btf_id = strtoul(*argv, &endptr, 0);
540 if (*endptr) {
541 p_err("can't parse %s as ID", *argv);
542 return -1;
543 }
544 NEXT_ARG();
545 } else if (is_prefix(src, "file")) {
546 if (is_btf_raw(*argv))
547 btf = btf__parse_raw(*argv);
548 else
549 btf = btf__parse_elf(*argv, NULL);
550
551 if (IS_ERR(btf)) {
552 err = PTR_ERR(btf);
553 btf = NULL;
554 p_err("failed to load BTF from %s: %s",
555 *argv, strerror(err));
556 goto done;
557 }
558 NEXT_ARG();
559 } else {
560 err = -1;
561 p_err("unrecognized BTF source specifier: '%s'", src);
562 goto done;
563 }
564
565 while (argc) {
566 if (is_prefix(*argv, "format")) {
567 NEXT_ARG();
568 if (argc < 1) {
569 p_err("expecting value for 'format' option\n");
570 goto done;
571 }
572 if (strcmp(*argv, "c") == 0) {
573 dump_c = true;
574 } else if (strcmp(*argv, "raw") == 0) {
575 dump_c = false;
576 } else {
577 p_err("unrecognized format specifier: '%s', possible values: raw, c",
578 *argv);
579 goto done;
580 }
581 NEXT_ARG();
582 } else {
583 p_err("unrecognized option: '%s'", *argv);
584 goto done;
585 }
586 }
587
588 if (!btf) {
589 err = btf__get_from_id(btf_id, &btf);
590 if (err) {
591 p_err("get btf by id (%u): %s", btf_id, strerror(err));
592 goto done;
593 }
594 if (!btf) {
595 err = ENOENT;
596 p_err("can't find btf with ID (%u)", btf_id);
597 goto done;
598 }
599 }
600
601 if (dump_c) {
602 if (json_output) {
603 p_err("JSON output for C-syntax dump is not supported");
604 err = -ENOTSUP;
605 goto done;
606 }
607 err = dump_btf_c(btf, root_type_ids, root_type_cnt);
608 } else {
609 err = dump_btf_raw(btf, root_type_ids, root_type_cnt);
610 }
611
612 done:
613 close(fd);
614 btf__free(btf);
615 return err;
616 }
617
618 static int btf_parse_fd(int *argc, char ***argv)
619 {
620 unsigned int id;
621 char *endptr;
622 int fd;
623
624 if (!is_prefix(*argv[0], "id")) {
625 p_err("expected 'id', got: '%s'?", **argv);
626 return -1;
627 }
628 NEXT_ARGP();
629
630 id = strtoul(**argv, &endptr, 0);
631 if (*endptr) {
632 p_err("can't parse %s as ID", **argv);
633 return -1;
634 }
635 NEXT_ARGP();
636
637 fd = bpf_btf_get_fd_by_id(id);
638 if (fd < 0)
639 p_err("can't get BTF object by id (%u): %s",
640 id, strerror(errno));
641
642 return fd;
643 }
644
645 static void delete_btf_table(struct btf_attach_table *tab)
646 {
647 struct btf_attach_point *obj;
648 struct hlist_node *tmp;
649
650 unsigned int bkt;
651
652 hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
653 hash_del(&obj->hash);
654 free(obj);
655 }
656 }
657
658 static int
659 build_btf_type_table(struct btf_attach_table *tab, enum bpf_obj_type type,
660 void *info, __u32 *len)
661 {
662 static const char * const names[] = {
663 [BPF_OBJ_UNKNOWN] = "unknown",
664 [BPF_OBJ_PROG] = "prog",
665 [BPF_OBJ_MAP] = "map",
666 };
667 struct btf_attach_point *obj_node;
668 __u32 btf_id, id = 0;
669 int err;
670 int fd;
671
672 while (true) {
673 switch (type) {
674 case BPF_OBJ_PROG:
675 err = bpf_prog_get_next_id(id, &id);
676 break;
677 case BPF_OBJ_MAP:
678 err = bpf_map_get_next_id(id, &id);
679 break;
680 default:
681 err = -1;
682 p_err("unexpected object type: %d", type);
683 goto err_free;
684 }
685 if (err) {
686 if (errno == ENOENT) {
687 err = 0;
688 break;
689 }
690 p_err("can't get next %s: %s%s", names[type],
691 strerror(errno),
692 errno == EINVAL ? " -- kernel too old?" : "");
693 goto err_free;
694 }
695
696 switch (type) {
697 case BPF_OBJ_PROG:
698 fd = bpf_prog_get_fd_by_id(id);
699 break;
700 case BPF_OBJ_MAP:
701 fd = bpf_map_get_fd_by_id(id);
702 break;
703 default:
704 err = -1;
705 p_err("unexpected object type: %d", type);
706 goto err_free;
707 }
708 if (fd < 0) {
709 if (errno == ENOENT)
710 continue;
711 p_err("can't get %s by id (%u): %s", names[type], id,
712 strerror(errno));
713 err = -1;
714 goto err_free;
715 }
716
717 memset(info, 0, *len);
718 err = bpf_obj_get_info_by_fd(fd, info, len);
719 close(fd);
720 if (err) {
721 p_err("can't get %s info: %s", names[type],
722 strerror(errno));
723 goto err_free;
724 }
725
726 switch (type) {
727 case BPF_OBJ_PROG:
728 btf_id = ((struct bpf_prog_info *)info)->btf_id;
729 break;
730 case BPF_OBJ_MAP:
731 btf_id = ((struct bpf_map_info *)info)->btf_id;
732 break;
733 default:
734 err = -1;
735 p_err("unexpected object type: %d", type);
736 goto err_free;
737 }
738 if (!btf_id)
739 continue;
740
741 obj_node = calloc(1, sizeof(*obj_node));
742 if (!obj_node) {
743 p_err("failed to allocate memory: %s", strerror(errno));
744 goto err_free;
745 }
746
747 obj_node->obj_id = id;
748 obj_node->btf_id = btf_id;
749 hash_add(tab->table, &obj_node->hash, obj_node->btf_id);
750 }
751
752 return 0;
753
754 err_free:
755 delete_btf_table(tab);
756 return err;
757 }
758
759 static int
760 build_btf_tables(struct btf_attach_table *btf_prog_table,
761 struct btf_attach_table *btf_map_table)
762 {
763 struct bpf_prog_info prog_info;
764 __u32 prog_len = sizeof(prog_info);
765 struct bpf_map_info map_info;
766 __u32 map_len = sizeof(map_info);
767 int err = 0;
768
769 err = build_btf_type_table(btf_prog_table, BPF_OBJ_PROG, &prog_info,
770 &prog_len);
771 if (err)
772 return err;
773
774 err = build_btf_type_table(btf_map_table, BPF_OBJ_MAP, &map_info,
775 &map_len);
776 if (err) {
777 delete_btf_table(btf_prog_table);
778 return err;
779 }
780
781 return 0;
782 }
783
784 static void
785 show_btf_plain(struct bpf_btf_info *info, int fd,
786 struct btf_attach_table *btf_prog_table,
787 struct btf_attach_table *btf_map_table)
788 {
789 struct btf_attach_point *obj;
790 int n;
791
792 printf("%u: ", info->id);
793 printf("size %uB", info->btf_size);
794
795 n = 0;
796 hash_for_each_possible(btf_prog_table->table, obj, hash, info->id) {
797 if (obj->btf_id == info->id)
798 printf("%s%u", n++ == 0 ? " prog_ids " : ",",
799 obj->obj_id);
800 }
801
802 n = 0;
803 hash_for_each_possible(btf_map_table->table, obj, hash, info->id) {
804 if (obj->btf_id == info->id)
805 printf("%s%u", n++ == 0 ? " map_ids " : ",",
806 obj->obj_id);
807 }
808
809 printf("\n");
810 }
811
812 static void
813 show_btf_json(struct bpf_btf_info *info, int fd,
814 struct btf_attach_table *btf_prog_table,
815 struct btf_attach_table *btf_map_table)
816 {
817 struct btf_attach_point *obj;
818
819 jsonw_start_object(json_wtr); /* btf object */
820 jsonw_uint_field(json_wtr, "id", info->id);
821 jsonw_uint_field(json_wtr, "size", info->btf_size);
822
823 jsonw_name(json_wtr, "prog_ids");
824 jsonw_start_array(json_wtr); /* prog_ids */
825 hash_for_each_possible(btf_prog_table->table, obj, hash,
826 info->id) {
827 if (obj->btf_id == info->id)
828 jsonw_uint(json_wtr, obj->obj_id);
829 }
830 jsonw_end_array(json_wtr); /* prog_ids */
831
832 jsonw_name(json_wtr, "map_ids");
833 jsonw_start_array(json_wtr); /* map_ids */
834 hash_for_each_possible(btf_map_table->table, obj, hash,
835 info->id) {
836 if (obj->btf_id == info->id)
837 jsonw_uint(json_wtr, obj->obj_id);
838 }
839 jsonw_end_array(json_wtr); /* map_ids */
840 jsonw_end_object(json_wtr); /* btf object */
841 }
842
843 static int
844 show_btf(int fd, struct btf_attach_table *btf_prog_table,
845 struct btf_attach_table *btf_map_table)
846 {
847 struct bpf_btf_info info = {};
848 __u32 len = sizeof(info);
849 int err;
850
851 err = bpf_obj_get_info_by_fd(fd, &info, &len);
852 if (err) {
853 p_err("can't get BTF object info: %s", strerror(errno));
854 return -1;
855 }
856
857 if (json_output)
858 show_btf_json(&info, fd, btf_prog_table, btf_map_table);
859 else
860 show_btf_plain(&info, fd, btf_prog_table, btf_map_table);
861
862 return 0;
863 }
864
865 static int do_show(int argc, char **argv)
866 {
867 struct btf_attach_table btf_prog_table;
868 struct btf_attach_table btf_map_table;
869 int err, fd = -1;
870 __u32 id = 0;
871
872 if (argc == 2) {
873 fd = btf_parse_fd(&argc, &argv);
874 if (fd < 0)
875 return -1;
876 }
877
878 if (argc) {
879 if (fd >= 0)
880 close(fd);
881 return BAD_ARG();
882 }
883
884 hash_init(btf_prog_table.table);
885 hash_init(btf_map_table.table);
886 err = build_btf_tables(&btf_prog_table, &btf_map_table);
887 if (err) {
888 if (fd >= 0)
889 close(fd);
890 return err;
891 }
892
893 if (fd >= 0) {
894 err = show_btf(fd, &btf_prog_table, &btf_map_table);
895 close(fd);
896 goto exit_free;
897 }
898
899 if (json_output)
900 jsonw_start_array(json_wtr); /* root array */
901
902 while (true) {
903 err = bpf_btf_get_next_id(id, &id);
904 if (err) {
905 if (errno == ENOENT) {
906 err = 0;
907 break;
908 }
909 p_err("can't get next BTF object: %s%s",
910 strerror(errno),
911 errno == EINVAL ? " -- kernel too old?" : "");
912 err = -1;
913 break;
914 }
915
916 fd = bpf_btf_get_fd_by_id(id);
917 if (fd < 0) {
918 if (errno == ENOENT)
919 continue;
920 p_err("can't get BTF object by id (%u): %s",
921 id, strerror(errno));
922 err = -1;
923 break;
924 }
925
926 err = show_btf(fd, &btf_prog_table, &btf_map_table);
927 close(fd);
928 if (err)
929 break;
930 }
931
932 if (json_output)
933 jsonw_end_array(json_wtr); /* root array */
934
935 exit_free:
936 delete_btf_table(&btf_prog_table);
937 delete_btf_table(&btf_map_table);
938
939 return err;
940 }
941
942 static int do_help(int argc, char **argv)
943 {
944 if (json_output) {
945 jsonw_null(json_wtr);
946 return 0;
947 }
948
949 fprintf(stderr,
950 "Usage: %s btf { show | list } [id BTF_ID]\n"
951 " %s btf dump BTF_SRC [format FORMAT]\n"
952 " %s btf help\n"
953 "\n"
954 " BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }\n"
955 " FORMAT := { raw | c }\n"
956 " " HELP_SPEC_MAP "\n"
957 " " HELP_SPEC_PROGRAM "\n"
958 " " HELP_SPEC_OPTIONS "\n"
959 "",
960 bin_name, bin_name, bin_name);
961
962 return 0;
963 }
964
965 static const struct cmd cmds[] = {
966 { "show", do_show },
967 { "list", do_show },
968 { "help", do_help },
969 { "dump", do_dump },
970 { 0 }
971 };
972
973 int do_btf(int argc, char **argv)
974 {
975 return cmd_select(cmds, argc, argv, do_help);
976 }
Linux with added FPC-III support