1// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2
3/*
4 * resolve_btfids scans ELF object for .BTF_ids section and resolves
5 * its symbols with BTF ID values.
6 *
7 * Each symbol points to 4 bytes data and is expected to have
8 * following name syntax:
9 *
10 * __BTF_ID__<type>__<symbol>[__<id>]
11 *
12 * type is:
13 *
14 * func - lookup BTF_KIND_FUNC symbol with <symbol> name
15 * and store its ID into the data:
16 *
17 * __BTF_ID__func__vfs_close__1:
18 * .zero 4
19 *
20 * struct - lookup BTF_KIND_STRUCT symbol with <symbol> name
21 * and store its ID into the data:
22 *
23 * __BTF_ID__struct__sk_buff__1:
24 * .zero 4
25 *
26 * union - lookup BTF_KIND_UNION symbol with <symbol> name
27 * and store its ID into the data:
28 *
29 * __BTF_ID__union__thread_union__1:
30 * .zero 4
31 *
32 * typedef - lookup BTF_KIND_TYPEDEF symbol with <symbol> name
33 * and store its ID into the data:
34 *
35 * __BTF_ID__typedef__pid_t__1:
36 * .zero 4
37 *
38 * set - store symbol size into first 4 bytes and sort following
39 * ID list
40 *
41 * __BTF_ID__set__list:
42 * .zero 4
43 * list:
44 * __BTF_ID__func__vfs_getattr__3:
45 * .zero 4
46 * __BTF_ID__func__vfs_fallocate__4:
47 * .zero 4
48 *
49 * set8 - store symbol size into first 4 bytes and sort following
50 * ID list
51 *
52 * __BTF_ID__set8__list:
53 * .zero 8
54 * list:
55 * __BTF_ID__func__vfs_getattr__3:
56 * .zero 4
57 * .word (1 << 0) | (1 << 2)
58 * __BTF_ID__func__vfs_fallocate__5:
59 * .zero 4
60 * .word (1 << 3) | (1 << 1) | (1 << 2)
61 */
62
63#define _GNU_SOURCE
64#include <stdio.h>
65#include <string.h>
66#include <unistd.h>
67#include <stdlib.h>
68#include <libelf.h>
69#include <gelf.h>
70#include <sys/stat.h>
71#include <fcntl.h>
72#include <errno.h>
73#include <linux/btf_ids.h>
74#include <linux/rbtree.h>
75#include <linux/zalloc.h>
76#include <linux/err.h>
77#include <bpf/btf.h>
78#include <bpf/libbpf.h>
79#include <subcmd/parse-options.h>
80
81#define BTF_IDS_SECTION ".BTF_ids"
82#define BTF_ID_PREFIX "__BTF_ID__"
83
84#define BTF_STRUCT "struct"
85#define BTF_UNION "union"
86#define BTF_TYPEDEF "typedef"
87#define BTF_FUNC "func"
88#define BTF_SET "set"
89#define BTF_SET8 "set8"
90
91#define ADDR_CNT 100
92
93#if __BYTE_ORDER == __LITTLE_ENDIAN
94# define ELFDATANATIVE ELFDATA2LSB
95#elif __BYTE_ORDER == __BIG_ENDIAN
96# define ELFDATANATIVE ELFDATA2MSB
97#else
98# error "Unknown machine endianness!"
99#endif
100
101struct btf_id {
102 struct rb_node rb_node;
103 char *name;
104 union {
105 int id;
106 int cnt;
107 };
108 int addr_cnt;
109 bool is_set;
110 bool is_set8;
111 Elf64_Addr addr[ADDR_CNT];
112};
113
114struct object {
115 const char *path;
116 const char *btf;
117 const char *base_btf_path;
118
119 struct {
120 int fd;
121 Elf *elf;
122 Elf_Data *symbols;
123 Elf_Data *idlist;
124 int symbols_shndx;
125 int idlist_shndx;
126 size_t strtabidx;
127 unsigned long idlist_addr;
128 int encoding;
129 } efile;
130
131 struct rb_root sets;
132 struct rb_root structs;
133 struct rb_root unions;
134 struct rb_root typedefs;
135 struct rb_root funcs;
136
137 int nr_funcs;
138 int nr_structs;
139 int nr_unions;
140 int nr_typedefs;
141};
142
143static int verbose;
144static int warnings;
145
146static int eprintf(int level, int var, const char *fmt, ...)
147{
148 va_list args;
149 int ret = 0;
150
151 if (var >= level) {
152 va_start(args, fmt);
153 ret = vfprintf(stderr, fmt, args);
154 va_end(args);
155 }
156 return ret;
157}
158
159#ifndef pr_fmt
160#define pr_fmt(fmt) fmt
161#endif
162
163#define pr_debug(fmt, ...) \
164 eprintf(1, verbose, pr_fmt(fmt), ##__VA_ARGS__)
165#define pr_debugN(n, fmt, ...) \
166 eprintf(n, verbose, pr_fmt(fmt), ##__VA_ARGS__)
167#define pr_debug2(fmt, ...) pr_debugN(2, pr_fmt(fmt), ##__VA_ARGS__)
168#define pr_err(fmt, ...) \
169 eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__)
170#define pr_info(fmt, ...) \
171 eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__)
172
173static bool is_btf_id(const char *name)
174{
175 return name && !strncmp(name, BTF_ID_PREFIX, sizeof(BTF_ID_PREFIX) - 1);
176}
177
178static struct btf_id *btf_id__find(struct rb_root *root, const char *name)
179{
180 struct rb_node *p = root->rb_node;
181 struct btf_id *id;
182 int cmp;
183
184 while (p) {
185 id = rb_entry(p, struct btf_id, rb_node);
186 cmp = strcmp(id->name, name);
187 if (cmp < 0)
188 p = p->rb_left;
189 else if (cmp > 0)
190 p = p->rb_right;
191 else
192 return id;
193 }
194 return NULL;
195}
196
197static struct btf_id *
198btf_id__add(struct rb_root *root, char *name, bool unique)
199{
200 struct rb_node **p = &root->rb_node;
201 struct rb_node *parent = NULL;
202 struct btf_id *id;
203 int cmp;
204
205 while (*p != NULL) {
206 parent = *p;
207 id = rb_entry(parent, struct btf_id, rb_node);
208 cmp = strcmp(id->name, name);
209 if (cmp < 0)
210 p = &(*p)->rb_left;
211 else if (cmp > 0)
212 p = &(*p)->rb_right;
213 else
214 return unique ? NULL : id;
215 }
216
217 id = zalloc(sizeof(*id));
218 if (id) {
219 pr_debug("adding symbol %s\n", name);
220 id->name = name;
221 rb_link_node(node: &id->rb_node, parent, rb_link: p);
222 rb_insert_color(&id->rb_node, root);
223 }
224 return id;
225}
226
227static char *get_id(const char *prefix_end)
228{
229 /*
230 * __BTF_ID__func__vfs_truncate__0
231 * prefix_end = ^
232 * pos = ^
233 */
234 int len = strlen(prefix_end);
235 int pos = sizeof("__") - 1;
236 char *p, *id;
237
238 if (pos >= len)
239 return NULL;
240
241 id = strdup(prefix_end + pos);
242 if (id) {
243 /*
244 * __BTF_ID__func__vfs_truncate__0
245 * id = ^
246 *
247 * cut the unique id part
248 */
249 p = strrchr(id, '_');
250 p--;
251 if (*p != '_') {
252 free(id);
253 return NULL;
254 }
255 *p = '\0';
256 }
257 return id;
258}
259
260static struct btf_id *add_set(struct object *obj, char *name, bool is_set8)
261{
262 /*
263 * __BTF_ID__set__name
264 * name = ^
265 * id = ^
266 */
267 char *id = name + (is_set8 ? sizeof(BTF_SET8 "__") : sizeof(BTF_SET "__")) - 1;
268 int len = strlen(name);
269
270 if (id >= name + len) {
271 pr_err("FAILED to parse set name: %s\n", name);
272 return NULL;
273 }
274
275 return btf_id__add(root: &obj->sets, name: id, unique: true);
276}
277
278static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
279{
280 char *id;
281
282 id = get_id(prefix_end: name + size);
283 if (!id) {
284 pr_err("FAILED to parse symbol name: %s\n", name);
285 return NULL;
286 }
287
288 return btf_id__add(root, name: id, unique: false);
289}
290
291/* Older libelf.h and glibc elf.h might not yet define the ELF compression types. */
292#ifndef SHF_COMPRESSED
293#define SHF_COMPRESSED (1 << 11) /* Section with compressed data. */
294#endif
295
296/*
297 * The data of compressed section should be aligned to 4
298 * (for 32bit) or 8 (for 64 bit) bytes. The binutils ld
299 * sets sh_addralign to 1, which makes libelf fail with
300 * misaligned section error during the update:
301 * FAILED elf_update(WRITE): invalid section alignment
302 *
303 * While waiting for ld fix, we fix the compressed sections
304 * sh_addralign value manualy.
305 */
306static int compressed_section_fix(Elf *elf, Elf_Scn *scn, GElf_Shdr *sh)
307{
308 int expected = gelf_getclass(elf) == ELFCLASS32 ? 4 : 8;
309
310 if (!(sh->sh_flags & SHF_COMPRESSED))
311 return 0;
312
313 if (sh->sh_addralign == expected)
314 return 0;
315
316 pr_debug2(" - fixing wrong alignment sh_addralign %u, expected %u\n",
317 sh->sh_addralign, expected);
318
319 sh->sh_addralign = expected;
320
321 if (gelf_update_shdr(scn, sh) == 0) {
322 pr_err("FAILED cannot update section header: %s\n",
323 elf_errmsg(-1));
324 return -1;
325 }
326 return 0;
327}
328
329static int elf_collect(struct object *obj)
330{
331 Elf_Scn *scn = NULL;
332 size_t shdrstrndx;
333 GElf_Ehdr ehdr;
334 int idx = 0;
335 Elf *elf;
336 int fd;
337
338 fd = open(obj->path, O_RDWR, 0666);
339 if (fd == -1) {
340 pr_err("FAILED cannot open %s: %s\n",
341 obj->path, strerror(errno));
342 return -1;
343 }
344
345 elf_version(EV_CURRENT);
346
347 elf = elf_begin(fd, ELF_C_RDWR_MMAP, NULL);
348 if (!elf) {
349 close(fd);
350 pr_err("FAILED cannot create ELF descriptor: %s\n",
351 elf_errmsg(-1));
352 return -1;
353 }
354
355 obj->efile.fd = fd;
356 obj->efile.elf = elf;
357
358 elf_flagelf(elf, ELF_C_SET, ELF_F_LAYOUT);
359
360 if (elf_getshdrstrndx(elf, &shdrstrndx) != 0) {
361 pr_err("FAILED cannot get shdr str ndx\n");
362 return -1;
363 }
364
365 if (gelf_getehdr(obj->efile.elf, &ehdr) == NULL) {
366 pr_err("FAILED cannot get ELF header: %s\n",
367 elf_errmsg(-1));
368 return -1;
369 }
370 obj->efile.encoding = ehdr.e_ident[EI_DATA];
371
372 /*
373 * Scan all the elf sections and look for save data
374 * from .BTF_ids section and symbols.
375 */
376 while ((scn = elf_nextscn(elf, scn)) != NULL) {
377 Elf_Data *data;
378 GElf_Shdr sh;
379 char *name;
380
381 idx++;
382 if (gelf_getshdr(scn, &sh) != &sh) {
383 pr_err("FAILED get section(%d) header\n", idx);
384 return -1;
385 }
386
387 name = elf_strptr(elf, shdrstrndx, sh.sh_name);
388 if (!name) {
389 pr_err("FAILED get section(%d) name\n", idx);
390 return -1;
391 }
392
393 data = elf_getdata(scn, 0);
394 if (!data) {
395 pr_err("FAILED to get section(%d) data from %s\n",
396 idx, name);
397 return -1;
398 }
399
400 pr_debug2("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
401 idx, name, (unsigned long) data->d_size,
402 (int) sh.sh_link, (unsigned long) sh.sh_flags,
403 (int) sh.sh_type);
404
405 if (sh.sh_type == SHT_SYMTAB) {
406 obj->efile.symbols = data;
407 obj->efile.symbols_shndx = idx;
408 obj->efile.strtabidx = sh.sh_link;
409 } else if (!strcmp(name, BTF_IDS_SECTION)) {
410 obj->efile.idlist = data;
411 obj->efile.idlist_shndx = idx;
412 obj->efile.idlist_addr = sh.sh_addr;
413 } else if (!strcmp(name, BTF_BASE_ELF_SEC)) {
414 /* If a .BTF.base section is found, do not resolve
415 * BTF ids relative to vmlinux; resolve relative
416 * to the .BTF.base section instead. btf__parse_split()
417 * will take care of this once the base BTF it is
418 * passed is NULL.
419 */
420 obj->base_btf_path = NULL;
421 }
422
423 if (compressed_section_fix(elf, scn, &sh))
424 return -1;
425 }
426
427 return 0;
428}
429
430static int symbols_collect(struct object *obj)
431{
432 Elf_Scn *scn = NULL;
433 int n, i;
434 GElf_Shdr sh;
435 char *name;
436
437 scn = elf_getscn(obj->efile.elf, obj->efile.symbols_shndx);
438 if (!scn)
439 return -1;
440
441 if (gelf_getshdr(scn, &sh) != &sh)
442 return -1;
443
444 n = sh.sh_size / sh.sh_entsize;
445
446 /*
447 * Scan symbols and look for the ones starting with
448 * __BTF_ID__* over .BTF_ids section.
449 */
450 for (i = 0; i < n; i++) {
451 char *prefix;
452 struct btf_id *id;
453 GElf_Sym sym;
454
455 if (!gelf_getsym(obj->efile.symbols, i, &sym))
456 return -1;
457
458 if (sym.st_shndx != obj->efile.idlist_shndx)
459 continue;
460
461 name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
462 sym.st_name);
463
464 if (!is_btf_id(name))
465 continue;
466
467 /*
468 * __BTF_ID__TYPE__vfs_truncate__0
469 * prefix = ^
470 */
471 prefix = name + sizeof(BTF_ID_PREFIX) - 1;
472
473 /* struct */
474 if (!strncmp(prefix, BTF_STRUCT, sizeof(BTF_STRUCT) - 1)) {
475 obj->nr_structs++;
476 id = add_symbol(root: &obj->structs, name: prefix, size: sizeof(BTF_STRUCT) - 1);
477 /* union */
478 } else if (!strncmp(prefix, BTF_UNION, sizeof(BTF_UNION) - 1)) {
479 obj->nr_unions++;
480 id = add_symbol(root: &obj->unions, name: prefix, size: sizeof(BTF_UNION) - 1);
481 /* typedef */
482 } else if (!strncmp(prefix, BTF_TYPEDEF, sizeof(BTF_TYPEDEF) - 1)) {
483 obj->nr_typedefs++;
484 id = add_symbol(root: &obj->typedefs, name: prefix, size: sizeof(BTF_TYPEDEF) - 1);
485 /* func */
486 } else if (!strncmp(prefix, BTF_FUNC, sizeof(BTF_FUNC) - 1)) {
487 obj->nr_funcs++;
488 id = add_symbol(root: &obj->funcs, name: prefix, size: sizeof(BTF_FUNC) - 1);
489 /* set8 */
490 } else if (!strncmp(prefix, BTF_SET8, sizeof(BTF_SET8) - 1)) {
491 id = add_set(obj, name: prefix, is_set8: true);
492 /*
493 * SET8 objects store list's count, which is encoded
494 * in symbol's size, together with 'cnt' field hence
495 * that - 1.
496 */
497 if (id) {
498 id->cnt = sym.st_size / sizeof(uint64_t) - 1;
499 id->is_set8 = true;
500 }
501 /* set */
502 } else if (!strncmp(prefix, BTF_SET, sizeof(BTF_SET) - 1)) {
503 id = add_set(obj, name: prefix, is_set8: false);
504 /*
505 * SET objects store list's count, which is encoded
506 * in symbol's size, together with 'cnt' field hence
507 * that - 1.
508 */
509 if (id) {
510 id->cnt = sym.st_size / sizeof(int) - 1;
511 id->is_set = true;
512 }
513 } else {
514 pr_err("FAILED unsupported prefix %s\n", prefix);
515 return -1;
516 }
517
518 if (!id)
519 return -ENOMEM;
520
521 if (id->addr_cnt >= ADDR_CNT) {
522 pr_err("FAILED symbol %s crossed the number of allowed lists\n",
523 id->name);
524 return -1;
525 }
526 id->addr[id->addr_cnt++] = sym.st_value;
527 }
528
529 return 0;
530}
531
532static int symbols_resolve(struct object *obj)
533{
534 int nr_typedefs = obj->nr_typedefs;
535 int nr_structs = obj->nr_structs;
536 int nr_unions = obj->nr_unions;
537 int nr_funcs = obj->nr_funcs;
538 struct btf *base_btf = NULL;
539 int err, type_id;
540 struct btf *btf;
541 __u32 nr_types;
542
543 if (obj->base_btf_path) {
544 base_btf = btf__parse(obj->base_btf_path, NULL);
545 err = libbpf_get_error(base_btf);
546 if (err) {
547 pr_err("FAILED: load base BTF from %s: %s\n",
548 obj->base_btf_path, strerror(-err));
549 return -1;
550 }
551 }
552
553 btf = btf__parse_split(obj->btf ?: obj->path, base_btf);
554 err = libbpf_get_error(btf);
555 if (err) {
556 pr_err("FAILED: load BTF from %s: %s\n",
557 obj->btf ?: obj->path, strerror(-err));
558 goto out;
559 }
560
561 err = -1;
562 nr_types = btf__type_cnt(btf);
563
564 /*
565 * Iterate all the BTF types and search for collected symbol IDs.
566 */
567 for (type_id = 1; type_id < nr_types; type_id++) {
568 const struct btf_type *type;
569 struct rb_root *root;
570 struct btf_id *id;
571 const char *str;
572 int *nr;
573
574 type = btf__type_by_id(btf, type_id);
575 if (!type) {
576 pr_err("FAILED: malformed BTF, can't resolve type for ID %d\n",
577 type_id);
578 goto out;
579 }
580
581 if (btf_is_func(type) && nr_funcs) {
582 nr = &nr_funcs;
583 root = &obj->funcs;
584 } else if (btf_is_struct(type) && nr_structs) {
585 nr = &nr_structs;
586 root = &obj->structs;
587 } else if (btf_is_union(type) && nr_unions) {
588 nr = &nr_unions;
589 root = &obj->unions;
590 } else if (btf_is_typedef(type) && nr_typedefs) {
591 nr = &nr_typedefs;
592 root = &obj->typedefs;
593 } else
594 continue;
595
596 str = btf__name_by_offset(btf, type->name_off);
597 if (!str) {
598 pr_err("FAILED: malformed BTF, can't resolve name for ID %d\n",
599 type_id);
600 goto out;
601 }
602
603 id = btf_id__find(root, name: str);
604 if (id) {
605 if (id->id) {
606 pr_info("WARN: multiple IDs found for '%s': %d, %d - using %d\n",
607 str, id->id, type_id, id->id);
608 warnings++;
609 } else {
610 id->id = type_id;
611 (*nr)--;
612 }
613 }
614 }
615
616 err = 0;
617out:
618 btf__free(base_btf);
619 btf__free(btf);
620 return err;
621}
622
623static int id_patch(struct object *obj, struct btf_id *id)
624{
625 Elf_Data *data = obj->efile.idlist;
626 int *ptr = data->d_buf;
627 int i;
628
629 /* For set, set8, id->id may be 0 */
630 if (!id->id && !id->is_set && !id->is_set8) {
631 pr_err("WARN: resolve_btfids: unresolved symbol %s\n", id->name);
632 warnings++;
633 }
634
635 for (i = 0; i < id->addr_cnt; i++) {
636 unsigned long addr = id->addr[i];
637 unsigned long idx = addr - obj->efile.idlist_addr;
638
639 pr_debug("patching addr %5lu: ID %7d [%s]\n",
640 idx, id->id, id->name);
641
642 if (idx >= data->d_size) {
643 pr_err("FAILED patching index %lu out of bounds %lu\n",
644 idx, data->d_size);
645 return -1;
646 }
647
648 idx = idx / sizeof(int);
649 ptr[idx] = id->id;
650 }
651
652 return 0;
653}
654
655static int __symbols_patch(struct object *obj, struct rb_root *root)
656{
657 struct rb_node *next;
658 struct btf_id *id;
659
660 next = rb_first(root);
661 while (next) {
662 id = rb_entry(next, struct btf_id, rb_node);
663
664 if (id_patch(obj, id))
665 return -1;
666
667 next = rb_next(next);
668 }
669 return 0;
670}
671
672static int cmp_id(const void *pa, const void *pb)
673{
674 const int *a = pa, *b = pb;
675
676 return *a - *b;
677}
678
679static int sets_patch(struct object *obj)
680{
681 Elf_Data *data = obj->efile.idlist;
682 struct rb_node *next;
683
684 next = rb_first(root: &obj->sets);
685 while (next) {
686 struct btf_id_set8 *set8 = NULL;
687 struct btf_id_set *set = NULL;
688 unsigned long addr, off;
689 struct btf_id *id;
690
691 id = rb_entry(next, struct btf_id, rb_node);
692 addr = id->addr[0];
693 off = addr - obj->efile.idlist_addr;
694
695 /* sets are unique */
696 if (id->addr_cnt != 1) {
697 pr_err("FAILED malformed data for set '%s'\n",
698 id->name);
699 return -1;
700 }
701
702 if (id->is_set) {
703 set = data->d_buf + off;
704 qsort(set->ids, set->cnt, sizeof(set->ids[0]), cmp_id);
705 } else {
706 set8 = data->d_buf + off;
707 /*
708 * Make sure id is at the beginning of the pairs
709 * struct, otherwise the below qsort would not work.
710 */
711 BUILD_BUG_ON((u32 *)set8->pairs != &set8->pairs[0].id);
712 qsort(set8->pairs, set8->cnt, sizeof(set8->pairs[0]), cmp_id);
713
714 /*
715 * When ELF endianness does not match endianness of the
716 * host, libelf will do the translation when updating
717 * the ELF. This, however, corrupts SET8 flags which are
718 * already in the target endianness. So, let's bswap
719 * them to the host endianness and libelf will then
720 * correctly translate everything.
721 */
722 if (obj->efile.encoding != ELFDATANATIVE) {
723 int i;
724
725 set8->flags = bswap_32(set8->flags);
726 for (i = 0; i < set8->cnt; i++) {
727 set8->pairs[i].flags =
728 bswap_32(set8->pairs[i].flags);
729 }
730 }
731 }
732
733 pr_debug("sorting addr %5lu: cnt %6d [%s]\n",
734 off, id->is_set ? set->cnt : set8->cnt, id->name);
735
736 next = rb_next(next);
737 }
738 return 0;
739}
740
741static int symbols_patch(struct object *obj)
742{
743 off_t err;
744
745 if (__symbols_patch(obj, root: &obj->structs) ||
746 __symbols_patch(obj, root: &obj->unions) ||
747 __symbols_patch(obj, root: &obj->typedefs) ||
748 __symbols_patch(obj, root: &obj->funcs) ||
749 __symbols_patch(obj, root: &obj->sets))
750 return -1;
751
752 if (sets_patch(obj))
753 return -1;
754
755 /* Set type to ensure endian translation occurs. */
756 obj->efile.idlist->d_type = ELF_T_WORD;
757
758 elf_flagdata(obj->efile.idlist, ELF_C_SET, ELF_F_DIRTY);
759
760 err = elf_update(obj->efile.elf, ELF_C_WRITE);
761 if (err < 0) {
762 pr_err("FAILED elf_update(WRITE): %s\n",
763 elf_errmsg(-1));
764 }
765
766 pr_debug("update %s for %s\n",
767 err >= 0 ? "ok" : "failed", obj->path);
768 return err < 0 ? -1 : 0;
769}
770
771static const char * const resolve_btfids_usage[] = {
772 "resolve_btfids [<options>] <ELF object>",
773 NULL
774};
775
776int main(int argc, const char **argv)
777{
778 struct object obj = {
779 .efile = {
780 .idlist_shndx = -1,
781 .symbols_shndx = -1,
782 },
783 .structs = RB_ROOT,
784 .unions = RB_ROOT,
785 .typedefs = RB_ROOT,
786 .funcs = RB_ROOT,
787 .sets = RB_ROOT,
788 };
789 bool fatal_warnings = false;
790 struct option btfid_options[] = {
791 OPT_INCR('v', "verbose", &verbose,
792 "be more verbose (show errors, etc)"),
793 OPT_STRING(0, "btf", &obj.btf, "BTF data",
794 "BTF data"),
795 OPT_STRING('b', "btf_base", &obj.base_btf_path, "file",
796 "path of file providing base BTF"),
797 OPT_BOOLEAN(0, "fatal_warnings", &fatal_warnings,
798 "turn warnings into errors"),
799 OPT_END()
800 };
801 int err = -1;
802
803 argc = parse_options(argc, argv, btfid_options, resolve_btfids_usage,
804 PARSE_OPT_STOP_AT_NON_OPTION);
805 if (argc != 1)
806 usage_with_options(resolve_btfids_usage, btfid_options);
807
808 obj.path = argv[0];
809
810 if (elf_collect(obj: &obj))
811 goto out;
812
813 /*
814 * We did not find .BTF_ids section or symbols section,
815 * nothing to do..
816 */
817 if (obj.efile.idlist_shndx == -1 ||
818 obj.efile.symbols_shndx == -1) {
819 pr_debug("Cannot find .BTF_ids or symbols sections, nothing to do\n");
820 err = 0;
821 goto out;
822 }
823
824 if (symbols_collect(obj: &obj))
825 goto out;
826
827 if (symbols_resolve(obj: &obj))
828 goto out;
829
830 if (symbols_patch(obj: &obj))
831 goto out;
832
833 if (!(fatal_warnings && warnings))
834 err = 0;
835out:
836 if (obj.efile.elf) {
837 elf_end(obj.efile.elf);
838 close(obj.efile.fd);
839 }
840 return err;
841}
842

source code of linux/tools/bpf/resolve_btfids/main.c