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