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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * build-id.c
4 *
5 * build-id support
6 *
7 * Copyright (C) 2009, 2010 Red Hat Inc.
8 * Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
9 */
10#include "util.h" // lsdir(), mkdir_p(), rm_rf()
11#include <dirent.h>
12#include <errno.h>
13#include <stdio.h>
14#include <sys/stat.h>
15#include <sys/types.h>
16#include "util/copyfile.h"
17#include "dso.h"
18#include "build-id.h"
19#include "event.h"
20#include "namespaces.h"
21#include "map.h"
22#include "symbol.h"
23#include "thread.h"
24#include <linux/kernel.h>
25#include "debug.h"
26#include "session.h"
27#include "tool.h"
28#include "header.h"
29#include "vdso.h"
30#include "path.h"
31#include "probe-file.h"
32#include "strlist.h"
33
34#include <linux/ctype.h>
35#include <linux/zalloc.h>
36
37static bool no_buildid_cache;
38
39int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
40 union perf_event *event,
41 struct perf_sample *sample,
42 struct evsel *evsel __maybe_unused,
43 struct machine *machine)
44{
45 struct addr_location al;
46 struct thread *thread = machine__findnew_thread(machine, sample->pid,
47 sample->tid);
48
49 if (thread == NULL) {
50 pr_err("problem processing %d event, skipping it.\n",
51 event->header.type);
52 return -1;
53 }
54
55 if (thread__find_map(thread, sample->cpumode, sample->ip, &al))
56 al.map->dso->hit = 1;
57
58 thread__put(thread);
59 return 0;
60}
61
62static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
63 union perf_event *event,
64 struct perf_sample *sample
65 __maybe_unused,
66 struct machine *machine)
67{
68 struct thread *thread = machine__findnew_thread(machine,
69 event->fork.pid,
70 event->fork.tid);
71
72 dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
73 event->fork.ppid, event->fork.ptid);
74
75 if (thread) {
76 machine__remove_thread(machine, thread);
77 thread__put(thread);
78 }
79
80 return 0;
81}
82
83struct perf_tool build_id__mark_dso_hit_ops = {
84 .sample = build_id__mark_dso_hit,
85 .mmap = perf_event__process_mmap,
86 .mmap2 = perf_event__process_mmap2,
87 .fork = perf_event__process_fork,
88 .exit = perf_event__exit_del_thread,
89 .attr = perf_event__process_attr,
90 .build_id = perf_event__process_build_id,
91 .ordered_events = true,
92};
93
94int build_id__sprintf(const u8 *build_id, int len, char *bf)
95{
96 char *bid = bf;
97 const u8 *raw = build_id;
98 int i;
99
100 for (i = 0; i < len; ++i) {
101 sprintf(bid, "%02x", *raw);
102 ++raw;
103 bid += 2;
104 }
105
106 return (bid - bf) + 1;
107}
108
109int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
110{
111 char notes[PATH_MAX];
112 u8 build_id[BUILD_ID_SIZE];
113 int ret;
114
115 if (!root_dir)
116 root_dir = "";
117
118 scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
119
120 ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
121 if (ret < 0)
122 return ret;
123
124 return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
125}
126
127int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
128{
129 u8 build_id[BUILD_ID_SIZE];
130 int ret;
131
132 ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
133 if (ret < 0)
134 return ret;
135 else if (ret != sizeof(build_id))
136 return -EINVAL;
137
138 return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
139}
140
141/* asnprintf consolidates asprintf and snprintf */
142static int asnprintf(char **strp, size_t size, const char *fmt, ...)
143{
144 va_list ap;
145 int ret;
146
147 if (!strp)
148 return -EINVAL;
149
150 va_start(ap, fmt);
151 if (*strp)
152 ret = vsnprintf(*strp, size, fmt, ap);
153 else
154 ret = vasprintf(strp, fmt, ap);
155 va_end(ap);
156
157 return ret;
158}
159
160char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
161 size_t size)
162{
163 bool retry_old = true;
164
165 snprintf(bf, size, "%s/%s/%s/kallsyms",
166 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
167retry:
168 if (!access(bf, F_OK))
169 return bf;
170 if (retry_old) {
171 /* Try old style kallsyms cache */
172 snprintf(bf, size, "%s/%s/%s",
173 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
174 retry_old = false;
175 goto retry;
176 }
177
178 return NULL;
179}
180
181char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size)
182{
183 char *tmp = bf;
184 int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
185 sbuild_id, sbuild_id + 2);
186 if (ret < 0 || (tmp && size < (unsigned int)ret))
187 return NULL;
188 return bf;
189}
190
191/* The caller is responsible to free the returned buffer. */
192char *build_id_cache__origname(const char *sbuild_id)
193{
194 char *linkname;
195 char buf[PATH_MAX];
196 char *ret = NULL, *p;
197 size_t offs = 5; /* == strlen("../..") */
198 ssize_t len;
199
200 linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
201 if (!linkname)
202 return NULL;
203
204 len = readlink(linkname, buf, sizeof(buf) - 1);
205 if (len <= 0)
206 goto out;
207 buf[len] = '\0';
208
209 /* The link should be "../..<origpath>/<sbuild_id>" */
210 p = strrchr(buf, '/'); /* Cut off the "/<sbuild_id>" */
211 if (p && (p > buf + offs)) {
212 *p = '\0';
213 if (buf[offs + 1] == '[')
214 offs++; /*
215 * This is a DSO name, like [kernel.kallsyms].
216 * Skip the first '/', since this is not the
217 * cache of a regular file.
218 */
219 ret = strdup(buf + offs); /* Skip "../..[/]" */
220 }
221out:
222 free(linkname);
223 return ret;
224}
225
226/* Check if the given build_id cache is valid on current running system */
227static bool build_id_cache__valid_id(char *sbuild_id)
228{
229 char real_sbuild_id[SBUILD_ID_SIZE] = "";
230 char *pathname;
231 int ret = 0;
232 bool result = false;
233
234 pathname = build_id_cache__origname(sbuild_id);
235 if (!pathname)
236 return false;
237
238 if (!strcmp(pathname, DSO__NAME_KALLSYMS))
239 ret = sysfs__sprintf_build_id("/", real_sbuild_id);
240 else if (pathname[0] == '/')
241 ret = filename__sprintf_build_id(pathname, real_sbuild_id);
242 else
243 ret = -EINVAL; /* Should we support other special DSO cache? */
244 if (ret >= 0)
245 result = (strcmp(sbuild_id, real_sbuild_id) == 0);
246 free(pathname);
247
248 return result;
249}
250
251static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
252 bool is_debug)
253{
254 return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
255 "debug" : "elf"));
256}
257
258char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
259 bool is_debug)
260{
261 bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
262 bool is_vdso = dso__is_vdso((struct dso *)dso);
263 char sbuild_id[SBUILD_ID_SIZE];
264 char *linkname;
265 bool alloc = (bf == NULL);
266 int ret;
267
268 if (!dso->has_build_id)
269 return NULL;
270
271 build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
272 linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
273 if (!linkname)
274 return NULL;
275
276 /* Check if old style build_id cache */
277 if (is_regular_file(linkname))
278 ret = asnprintf(&bf, size, "%s", linkname);
279 else
280 ret = asnprintf(&bf, size, "%s/%s", linkname,
281 build_id_cache__basename(is_kallsyms, is_vdso,
282 is_debug));
283 if (ret < 0 || (!alloc && size < (unsigned int)ret))
284 bf = NULL;
285 free(linkname);
286
287 return bf;
288}
289
290#define dsos__for_each_with_build_id(pos, head) \
291 list_for_each_entry(pos, head, node) \
292 if (!pos->has_build_id) \
293 continue; \
294 else
295
296static int write_buildid(const char *name, size_t name_len, u8 *build_id,
297 pid_t pid, u16 misc, struct feat_fd *fd)
298{
299 int err;
300 struct perf_record_header_build_id b;
301 size_t len;
302
303 len = name_len + 1;
304 len = PERF_ALIGN(len, NAME_ALIGN);
305
306 memset(&b, 0, sizeof(b));
307 memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
308 b.pid = pid;
309 b.header.misc = misc;
310 b.header.size = sizeof(b) + len;
311
312 err = do_write(fd, &b, sizeof(b));
313 if (err < 0)
314 return err;
315
316 return write_padded(fd, name, name_len + 1, len);
317}
318
319static int machine__write_buildid_table(struct machine *machine,
320 struct feat_fd *fd)
321{
322 int err = 0;
323 struct dso *pos;
324 u16 kmisc = PERF_RECORD_MISC_KERNEL,
325 umisc = PERF_RECORD_MISC_USER;
326
327 if (!machine__is_host(machine)) {
328 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
329 umisc = PERF_RECORD_MISC_GUEST_USER;
330 }
331
332 dsos__for_each_with_build_id(pos, &machine->dsos.head) {
333 const char *name;
334 size_t name_len;
335 bool in_kernel = false;
336
337 if (!pos->hit && !dso__is_vdso(pos))
338 continue;
339
340 if (dso__is_vdso(pos)) {
341 name = pos->short_name;
342 name_len = pos->short_name_len;
343 } else if (dso__is_kcore(pos)) {
344 name = machine->mmap_name;
345 name_len = strlen(name);
346 } else {
347 name = pos->long_name;
348 name_len = pos->long_name_len;
349 }
350
351 in_kernel = pos->kernel ||
352 is_kernel_module(name,
353 PERF_RECORD_MISC_CPUMODE_UNKNOWN);
354 err = write_buildid(name, name_len, pos->build_id, machine->pid,
355 in_kernel ? kmisc : umisc, fd);
356 if (err)
357 break;
358 }
359
360 return err;
361}
362
363int perf_session__write_buildid_table(struct perf_session *session,
364 struct feat_fd *fd)
365{
366 struct rb_node *nd;
367 int err = machine__write_buildid_table(&session->machines.host, fd);
368
369 if (err)
370 return err;
371
372 for (nd = rb_first_cached(&session->machines.guests); nd;
373 nd = rb_next(nd)) {
374 struct machine *pos = rb_entry(nd, struct machine, rb_node);
375 err = machine__write_buildid_table(pos, fd);
376 if (err)
377 break;
378 }
379 return err;
380}
381
382static int __dsos__hit_all(struct list_head *head)
383{
384 struct dso *pos;
385
386 list_for_each_entry(pos, head, node)
387 pos->hit = true;
388
389 return 0;
390}
391
392static int machine__hit_all_dsos(struct machine *machine)
393{
394 return __dsos__hit_all(&machine->dsos.head);
395}
396
397int dsos__hit_all(struct perf_session *session)
398{
399 struct rb_node *nd;
400 int err;
401
402 err = machine__hit_all_dsos(&session->machines.host);
403 if (err)
404 return err;
405
406 for (nd = rb_first_cached(&session->machines.guests); nd;
407 nd = rb_next(nd)) {
408 struct machine *pos = rb_entry(nd, struct machine, rb_node);
409
410 err = machine__hit_all_dsos(pos);
411 if (err)
412 return err;
413 }
414
415 return 0;
416}
417
418void disable_buildid_cache(void)
419{
420 no_buildid_cache = true;
421}
422
423static bool lsdir_bid_head_filter(const char *name __maybe_unused,
424 struct dirent *d)
425{
426 return (strlen(d->d_name) == 2) &&
427 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
428}
429
430static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
431 struct dirent *d)
432{
433 int i = 0;
434 while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
435 i++;
436 return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
437}
438
439struct strlist *build_id_cache__list_all(bool validonly)
440{
441 struct strlist *toplist, *linklist = NULL, *bidlist;
442 struct str_node *nd, *nd2;
443 char *topdir, *linkdir = NULL;
444 char sbuild_id[SBUILD_ID_SIZE];
445
446 /* for filename__ functions */
447 if (validonly)
448 symbol__init(NULL);
449
450 /* Open the top-level directory */
451 if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
452 return NULL;
453
454 bidlist = strlist__new(NULL, NULL);
455 if (!bidlist)
456 goto out;
457
458 toplist = lsdir(topdir, lsdir_bid_head_filter);
459 if (!toplist) {
460 pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
461 /* If there is no buildid cache, return an empty list */
462 if (errno == ENOENT)
463 goto out;
464 goto err_out;
465 }
466
467 strlist__for_each_entry(nd, toplist) {
468 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
469 goto err_out;
470 /* Open the lower-level directory */
471 linklist = lsdir(linkdir, lsdir_bid_tail_filter);
472 if (!linklist) {
473 pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
474 goto err_out;
475 }
476 strlist__for_each_entry(nd2, linklist) {
477 if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
478 nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
479 goto err_out;
480 if (validonly && !build_id_cache__valid_id(sbuild_id))
481 continue;
482 if (strlist__add(bidlist, sbuild_id) < 0)
483 goto err_out;
484 }
485 strlist__delete(linklist);
486 zfree(&linkdir);
487 }
488
489out_free:
490 strlist__delete(toplist);
491out:
492 free(topdir);
493
494 return bidlist;
495
496err_out:
497 strlist__delete(linklist);
498 zfree(&linkdir);
499 strlist__delete(bidlist);
500 bidlist = NULL;
501 goto out_free;
502}
503
504static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
505{
506 size_t i;
507
508 for (i = 0; i < len; i++) {
509 if (!isxdigit(maybe_sbuild_id[i]))
510 return false;
511 }
512 return true;
513}
514
515/* Return the valid complete build-id */
516char *build_id_cache__complement(const char *incomplete_sbuild_id)
517{
518 struct strlist *bidlist;
519 struct str_node *nd, *cand = NULL;
520 char *sbuild_id = NULL;
521 size_t len = strlen(incomplete_sbuild_id);
522
523 if (len >= SBUILD_ID_SIZE ||
524 !str_is_build_id(incomplete_sbuild_id, len))
525 return NULL;
526
527 bidlist = build_id_cache__list_all(true);
528 if (!bidlist)
529 return NULL;
530
531 strlist__for_each_entry(nd, bidlist) {
532 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
533 continue;
534 if (cand) { /* Error: There are more than 2 candidates. */
535 cand = NULL;
536 break;
537 }
538 cand = nd;
539 }
540 if (cand)
541 sbuild_id = strdup(cand->s);
542 strlist__delete(bidlist);
543
544 return sbuild_id;
545}
546
547char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
548 struct nsinfo *nsi, bool is_kallsyms,
549 bool is_vdso)
550{
551 char *realname = (char *)name, *filename;
552 bool slash = is_kallsyms || is_vdso;
553
554 if (!slash) {
555 realname = nsinfo__realpath(name, nsi);
556 if (!realname)
557 return NULL;
558 }
559
560 if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
561 is_vdso ? DSO__NAME_VDSO : realname,
562 sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
563 filename = NULL;
564
565 if (!slash)
566 free(realname);
567
568 return filename;
569}
570
571int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi,
572 struct strlist **result)
573{
574 char *dir_name;
575 int ret = 0;
576
577 dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false);
578 if (!dir_name)
579 return -ENOMEM;
580
581 *result = lsdir(dir_name, lsdir_no_dot_filter);
582 if (!*result)
583 ret = -errno;
584 free(dir_name);
585
586 return ret;
587}
588
589#if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
590static int build_id_cache__add_sdt_cache(const char *sbuild_id,
591 const char *realname,
592 struct nsinfo *nsi)
593{
594 struct probe_cache *cache;
595 int ret;
596 struct nscookie nsc;
597
598 cache = probe_cache__new(sbuild_id, nsi);
599 if (!cache)
600 return -1;
601
602 nsinfo__mountns_enter(nsi, &nsc);
603 ret = probe_cache__scan_sdt(cache, realname);
604 nsinfo__mountns_exit(&nsc);
605 if (ret >= 0) {
606 pr_debug4("Found %d SDTs in %s\n", ret, realname);
607 if (probe_cache__commit(cache) < 0)
608 ret = -1;
609 }
610 probe_cache__delete(cache);
611 return ret;
612}
613#else
614#define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0)
615#endif
616
617static char *build_id_cache__find_debug(const char *sbuild_id,
618 struct nsinfo *nsi)
619{
620 char *realname = NULL;
621 char *debugfile;
622 struct nscookie nsc;
623 size_t len = 0;
624
625 debugfile = calloc(1, PATH_MAX);
626 if (!debugfile)
627 goto out;
628
629 len = __symbol__join_symfs(debugfile, PATH_MAX,
630 "/usr/lib/debug/.build-id/");
631 snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id,
632 sbuild_id + 2);
633
634 nsinfo__mountns_enter(nsi, &nsc);
635 realname = realpath(debugfile, NULL);
636 if (realname && access(realname, R_OK))
637 zfree(&realname);
638 nsinfo__mountns_exit(&nsc);
639out:
640 free(debugfile);
641 return realname;
642}
643
644int build_id_cache__add_s(const char *sbuild_id, const char *name,
645 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso)
646{
647 const size_t size = PATH_MAX;
648 char *realname = NULL, *filename = NULL, *dir_name = NULL,
649 *linkname = zalloc(size), *tmp;
650 char *debugfile = NULL;
651 int err = -1;
652
653 if (!is_kallsyms) {
654 if (!is_vdso)
655 realname = nsinfo__realpath(name, nsi);
656 else
657 realname = realpath(name, NULL);
658 if (!realname)
659 goto out_free;
660 }
661
662 dir_name = build_id_cache__cachedir(sbuild_id, name, nsi, is_kallsyms,
663 is_vdso);
664 if (!dir_name)
665 goto out_free;
666
667 /* Remove old style build-id cache */
668 if (is_regular_file(dir_name))
669 if (unlink(dir_name))
670 goto out_free;
671
672 if (mkdir_p(dir_name, 0755))
673 goto out_free;
674
675 /* Save the allocated buildid dirname */
676 if (asprintf(&filename, "%s/%s", dir_name,
677 build_id_cache__basename(is_kallsyms, is_vdso,
678 false)) < 0) {
679 filename = NULL;
680 goto out_free;
681 }
682
683 if (access(filename, F_OK)) {
684 if (is_kallsyms) {
685 if (copyfile("/proc/kallsyms", filename))
686 goto out_free;
687 } else if (nsi && nsi->need_setns) {
688 if (copyfile_ns(name, filename, nsi))
689 goto out_free;
690 } else if (link(realname, filename) && errno != EEXIST &&
691 copyfile(name, filename))
692 goto out_free;
693 }
694
695 /* Some binaries are stripped, but have .debug files with their symbol
696 * table. Check to see if we can locate one of those, since the elf
697 * file itself may not be very useful to users of our tools without a
698 * symtab.
699 */
700 if (!is_kallsyms && !is_vdso &&
701 strncmp(".ko", name + strlen(name) - 3, 3)) {
702 debugfile = build_id_cache__find_debug(sbuild_id, nsi);
703 if (debugfile) {
704 zfree(&filename);
705 if (asprintf(&filename, "%s/%s", dir_name,
706 build_id_cache__basename(false, false, true)) < 0) {
707 filename = NULL;
708 goto out_free;
709 }
710 if (access(filename, F_OK)) {
711 if (nsi && nsi->need_setns) {
712 if (copyfile_ns(debugfile, filename,
713 nsi))
714 goto out_free;
715 } else if (link(debugfile, filename) &&
716 errno != EEXIST &&
717 copyfile(debugfile, filename))
718 goto out_free;
719 }
720 }
721 }
722
723 if (!build_id_cache__linkname(sbuild_id, linkname, size))
724 goto out_free;
725 tmp = strrchr(linkname, '/');
726 *tmp = '\0';
727
728 if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
729 goto out_free;
730
731 *tmp = '/';
732 tmp = dir_name + strlen(buildid_dir) - 5;
733 memcpy(tmp, "../..", 5);
734
735 if (symlink(tmp, linkname) == 0)
736 err = 0;
737
738 /* Update SDT cache : error is just warned */
739 if (realname &&
740 build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0)
741 pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
742
743out_free:
744 if (!is_kallsyms)
745 free(realname);
746 free(filename);
747 free(debugfile);
748 free(dir_name);
749 free(linkname);
750 return err;
751}
752
753static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
754 const char *name, struct nsinfo *nsi,
755 bool is_kallsyms, bool is_vdso)
756{
757 char sbuild_id[SBUILD_ID_SIZE];
758
759 build_id__sprintf(build_id, build_id_size, sbuild_id);
760
761 return build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms,
762 is_vdso);
763}
764
765bool build_id_cache__cached(const char *sbuild_id)
766{
767 bool ret = false;
768 char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
769
770 if (filename && !access(filename, F_OK))
771 ret = true;
772 free(filename);
773
774 return ret;
775}
776
777int build_id_cache__remove_s(const char *sbuild_id)
778{
779 const size_t size = PATH_MAX;
780 char *filename = zalloc(size),
781 *linkname = zalloc(size), *tmp;
782 int err = -1;
783
784 if (filename == NULL || linkname == NULL)
785 goto out_free;
786
787 if (!build_id_cache__linkname(sbuild_id, linkname, size))
788 goto out_free;
789
790 if (access(linkname, F_OK))
791 goto out_free;
792
793 if (readlink(linkname, filename, size - 1) < 0)
794 goto out_free;
795
796 if (unlink(linkname))
797 goto out_free;
798
799 /*
800 * Since the link is relative, we must make it absolute:
801 */
802 tmp = strrchr(linkname, '/') + 1;
803 snprintf(tmp, size - (tmp - linkname), "%s", filename);
804
805 if (rm_rf(linkname))
806 goto out_free;
807
808 err = 0;
809out_free:
810 free(filename);
811 free(linkname);
812 return err;
813}
814
815static int dso__cache_build_id(struct dso *dso, struct machine *machine)
816{
817 bool is_kallsyms = dso__is_kallsyms(dso);
818 bool is_vdso = dso__is_vdso(dso);
819 const char *name = dso->long_name;
820
821 if (dso__is_kcore(dso)) {
822 is_kallsyms = true;
823 name = machine->mmap_name;
824 }
825 return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
826 dso->nsinfo, is_kallsyms, is_vdso);
827}
828
829static int __dsos__cache_build_ids(struct list_head *head,
830 struct machine *machine)
831{
832 struct dso *pos;
833 int err = 0;
834
835 dsos__for_each_with_build_id(pos, head)
836 if (dso__cache_build_id(pos, machine))
837 err = -1;
838
839 return err;
840}
841
842static int machine__cache_build_ids(struct machine *machine)
843{
844 return __dsos__cache_build_ids(&machine->dsos.head, machine);
845}
846
847int perf_session__cache_build_ids(struct perf_session *session)
848{
849 struct rb_node *nd;
850 int ret;
851
852 if (no_buildid_cache)
853 return 0;
854
855 if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
856 return -1;
857
858 ret = machine__cache_build_ids(&session->machines.host);
859
860 for (nd = rb_first_cached(&session->machines.guests); nd;
861 nd = rb_next(nd)) {
862 struct machine *pos = rb_entry(nd, struct machine, rb_node);
863 ret |= machine__cache_build_ids(pos);
864 }
865 return ret ? -1 : 0;
866}
867
868static bool machine__read_build_ids(struct machine *machine, bool with_hits)
869{
870 return __dsos__read_build_ids(&machine->dsos.head, with_hits);
871}
872
873bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
874{
875 struct rb_node *nd;
876 bool ret = machine__read_build_ids(&session->machines.host, with_hits);
877
878 for (nd = rb_first_cached(&session->machines.guests); nd;
879 nd = rb_next(nd)) {
880 struct machine *pos = rb_entry(nd, struct machine, rb_node);
881 ret |= machine__read_build_ids(pos, with_hits);
882 }
883
884 return ret;
885}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * build-id.c
4 *
5 * build-id support
6 *
7 * Copyright (C) 2009, 2010 Red Hat Inc.
8 * Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
9 */
10#include "util.h" // lsdir(), mkdir_p(), rm_rf()
11#include <dirent.h>
12#include <errno.h>
13#include <stdio.h>
14#include <sys/stat.h>
15#include <sys/types.h>
16#include "util/copyfile.h"
17#include "dso.h"
18#include "build-id.h"
19#include "event.h"
20#include "namespaces.h"
21#include "map.h"
22#include "symbol.h"
23#include "thread.h"
24#include <linux/kernel.h>
25#include "debug.h"
26#include "session.h"
27#include "tool.h"
28#include "header.h"
29#include "vdso.h"
30#include "path.h"
31#include "probe-file.h"
32#include "strlist.h"
33
34#ifdef HAVE_DEBUGINFOD_SUPPORT
35#include <elfutils/debuginfod.h>
36#endif
37
38#include <linux/ctype.h>
39#include <linux/zalloc.h>
40#include <linux/string.h>
41#include <asm/bug.h>
42
43static bool no_buildid_cache;
44
45int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
46 union perf_event *event,
47 struct perf_sample *sample,
48 struct evsel *evsel __maybe_unused,
49 struct machine *machine)
50{
51 struct addr_location al;
52 struct thread *thread = machine__findnew_thread(machine, sample->pid,
53 sample->tid);
54
55 if (thread == NULL) {
56 pr_err("problem processing %d event, skipping it.\n",
57 event->header.type);
58 return -1;
59 }
60
61 addr_location__init(&al);
62 if (thread__find_map(thread, sample->cpumode, sample->ip, &al))
63 map__dso(al.map)->hit = 1;
64
65 addr_location__exit(&al);
66 thread__put(thread);
67 return 0;
68}
69
70static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
71 union perf_event *event,
72 struct perf_sample *sample
73 __maybe_unused,
74 struct machine *machine)
75{
76 struct thread *thread = machine__findnew_thread(machine,
77 event->fork.pid,
78 event->fork.tid);
79
80 dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
81 event->fork.ppid, event->fork.ptid);
82
83 if (thread) {
84 machine__remove_thread(machine, thread);
85 thread__put(thread);
86 }
87
88 return 0;
89}
90
91struct perf_tool build_id__mark_dso_hit_ops = {
92 .sample = build_id__mark_dso_hit,
93 .mmap = perf_event__process_mmap,
94 .mmap2 = perf_event__process_mmap2,
95 .fork = perf_event__process_fork,
96 .exit = perf_event__exit_del_thread,
97 .attr = perf_event__process_attr,
98 .build_id = perf_event__process_build_id,
99 .ordered_events = true,
100};
101
102int build_id__sprintf(const struct build_id *build_id, char *bf)
103{
104 char *bid = bf;
105 const u8 *raw = build_id->data;
106 size_t i;
107
108 bf[0] = 0x0;
109
110 for (i = 0; i < build_id->size; ++i) {
111 sprintf(bid, "%02x", *raw);
112 ++raw;
113 bid += 2;
114 }
115
116 return (bid - bf) + 1;
117}
118
119int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
120{
121 char notes[PATH_MAX];
122 struct build_id bid;
123 int ret;
124
125 if (!root_dir)
126 root_dir = "";
127
128 scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
129
130 ret = sysfs__read_build_id(notes, &bid);
131 if (ret < 0)
132 return ret;
133
134 return build_id__sprintf(&bid, sbuild_id);
135}
136
137int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
138{
139 struct build_id bid;
140 int ret;
141
142 ret = filename__read_build_id(pathname, &bid);
143 if (ret < 0)
144 return ret;
145
146 return build_id__sprintf(&bid, sbuild_id);
147}
148
149/* asnprintf consolidates asprintf and snprintf */
150static int asnprintf(char **strp, size_t size, const char *fmt, ...)
151{
152 va_list ap;
153 int ret;
154
155 if (!strp)
156 return -EINVAL;
157
158 va_start(ap, fmt);
159 if (*strp)
160 ret = vsnprintf(*strp, size, fmt, ap);
161 else
162 ret = vasprintf(strp, fmt, ap);
163 va_end(ap);
164
165 return ret;
166}
167
168char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
169 size_t size)
170{
171 bool retry_old = true;
172
173 snprintf(bf, size, "%s/%s/%s/kallsyms",
174 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
175retry:
176 if (!access(bf, F_OK))
177 return bf;
178 if (retry_old) {
179 /* Try old style kallsyms cache */
180 snprintf(bf, size, "%s/%s/%s",
181 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
182 retry_old = false;
183 goto retry;
184 }
185
186 return NULL;
187}
188
189char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size)
190{
191 char *tmp = bf;
192 int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
193 sbuild_id, sbuild_id + 2);
194 if (ret < 0 || (tmp && size < (unsigned int)ret))
195 return NULL;
196 return bf;
197}
198
199/* The caller is responsible to free the returned buffer. */
200char *build_id_cache__origname(const char *sbuild_id)
201{
202 char *linkname;
203 char buf[PATH_MAX];
204 char *ret = NULL, *p;
205 size_t offs = 5; /* == strlen("../..") */
206 ssize_t len;
207
208 linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
209 if (!linkname)
210 return NULL;
211
212 len = readlink(linkname, buf, sizeof(buf) - 1);
213 if (len <= 0)
214 goto out;
215 buf[len] = '\0';
216
217 /* The link should be "../..<origpath>/<sbuild_id>" */
218 p = strrchr(buf, '/'); /* Cut off the "/<sbuild_id>" */
219 if (p && (p > buf + offs)) {
220 *p = '\0';
221 if (buf[offs + 1] == '[')
222 offs++; /*
223 * This is a DSO name, like [kernel.kallsyms].
224 * Skip the first '/', since this is not the
225 * cache of a regular file.
226 */
227 ret = strdup(buf + offs); /* Skip "../..[/]" */
228 }
229out:
230 free(linkname);
231 return ret;
232}
233
234/* Check if the given build_id cache is valid on current running system */
235static bool build_id_cache__valid_id(char *sbuild_id)
236{
237 char real_sbuild_id[SBUILD_ID_SIZE] = "";
238 char *pathname;
239 int ret = 0;
240 bool result = false;
241
242 pathname = build_id_cache__origname(sbuild_id);
243 if (!pathname)
244 return false;
245
246 if (!strcmp(pathname, DSO__NAME_KALLSYMS))
247 ret = sysfs__sprintf_build_id("/", real_sbuild_id);
248 else if (pathname[0] == '/')
249 ret = filename__sprintf_build_id(pathname, real_sbuild_id);
250 else
251 ret = -EINVAL; /* Should we support other special DSO cache? */
252 if (ret >= 0)
253 result = (strcmp(sbuild_id, real_sbuild_id) == 0);
254 free(pathname);
255
256 return result;
257}
258
259static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
260 bool is_debug)
261{
262 return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
263 "debug" : "elf"));
264}
265
266char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
267 bool is_debug, bool is_kallsyms)
268{
269 bool is_vdso = dso__is_vdso((struct dso *)dso);
270 char sbuild_id[SBUILD_ID_SIZE];
271 char *linkname;
272 bool alloc = (bf == NULL);
273 int ret;
274
275 if (!dso->has_build_id)
276 return NULL;
277
278 build_id__sprintf(&dso->bid, sbuild_id);
279 linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
280 if (!linkname)
281 return NULL;
282
283 /* Check if old style build_id cache */
284 if (is_regular_file(linkname))
285 ret = asnprintf(&bf, size, "%s", linkname);
286 else
287 ret = asnprintf(&bf, size, "%s/%s", linkname,
288 build_id_cache__basename(is_kallsyms, is_vdso,
289 is_debug));
290 if (ret < 0 || (!alloc && size < (unsigned int)ret))
291 bf = NULL;
292 free(linkname);
293
294 return bf;
295}
296
297char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
298 bool is_debug)
299{
300 bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
301
302 return __dso__build_id_filename(dso, bf, size, is_debug, is_kallsyms);
303}
304
305static int write_buildid(const char *name, size_t name_len, struct build_id *bid,
306 pid_t pid, u16 misc, struct feat_fd *fd)
307{
308 int err;
309 struct perf_record_header_build_id b;
310 size_t len;
311
312 len = name_len + 1;
313 len = PERF_ALIGN(len, NAME_ALIGN);
314
315 memset(&b, 0, sizeof(b));
316 memcpy(&b.data, bid->data, bid->size);
317 b.size = (u8) bid->size;
318 misc |= PERF_RECORD_MISC_BUILD_ID_SIZE;
319 b.pid = pid;
320 b.header.misc = misc;
321 b.header.size = sizeof(b) + len;
322
323 err = do_write(fd, &b, sizeof(b));
324 if (err < 0)
325 return err;
326
327 return write_padded(fd, name, name_len + 1, len);
328}
329
330static int machine__write_buildid_table(struct machine *machine,
331 struct feat_fd *fd)
332{
333 int err = 0;
334 struct dso *pos;
335 u16 kmisc = PERF_RECORD_MISC_KERNEL,
336 umisc = PERF_RECORD_MISC_USER;
337
338 if (!machine__is_host(machine)) {
339 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
340 umisc = PERF_RECORD_MISC_GUEST_USER;
341 }
342
343 dsos__for_each_with_build_id(pos, &machine->dsos.head) {
344 const char *name;
345 size_t name_len;
346 bool in_kernel = false;
347
348 if (!pos->hit && !dso__is_vdso(pos))
349 continue;
350
351 if (dso__is_vdso(pos)) {
352 name = pos->short_name;
353 name_len = pos->short_name_len;
354 } else if (dso__is_kcore(pos)) {
355 name = machine->mmap_name;
356 name_len = strlen(name);
357 } else {
358 name = pos->long_name;
359 name_len = pos->long_name_len;
360 }
361
362 in_kernel = pos->kernel ||
363 is_kernel_module(name,
364 PERF_RECORD_MISC_CPUMODE_UNKNOWN);
365 err = write_buildid(name, name_len, &pos->bid, machine->pid,
366 in_kernel ? kmisc : umisc, fd);
367 if (err)
368 break;
369 }
370
371 return err;
372}
373
374int perf_session__write_buildid_table(struct perf_session *session,
375 struct feat_fd *fd)
376{
377 struct rb_node *nd;
378 int err = machine__write_buildid_table(&session->machines.host, fd);
379
380 if (err)
381 return err;
382
383 for (nd = rb_first_cached(&session->machines.guests); nd;
384 nd = rb_next(nd)) {
385 struct machine *pos = rb_entry(nd, struct machine, rb_node);
386 err = machine__write_buildid_table(pos, fd);
387 if (err)
388 break;
389 }
390 return err;
391}
392
393static int __dsos__hit_all(struct list_head *head)
394{
395 struct dso *pos;
396
397 list_for_each_entry(pos, head, node)
398 pos->hit = true;
399
400 return 0;
401}
402
403static int machine__hit_all_dsos(struct machine *machine)
404{
405 return __dsos__hit_all(&machine->dsos.head);
406}
407
408int dsos__hit_all(struct perf_session *session)
409{
410 struct rb_node *nd;
411 int err;
412
413 err = machine__hit_all_dsos(&session->machines.host);
414 if (err)
415 return err;
416
417 for (nd = rb_first_cached(&session->machines.guests); nd;
418 nd = rb_next(nd)) {
419 struct machine *pos = rb_entry(nd, struct machine, rb_node);
420
421 err = machine__hit_all_dsos(pos);
422 if (err)
423 return err;
424 }
425
426 return 0;
427}
428
429void disable_buildid_cache(void)
430{
431 no_buildid_cache = true;
432}
433
434static bool lsdir_bid_head_filter(const char *name __maybe_unused,
435 struct dirent *d)
436{
437 return (strlen(d->d_name) == 2) &&
438 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
439}
440
441static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
442 struct dirent *d)
443{
444 int i = 0;
445 while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
446 i++;
447 return (i >= SBUILD_ID_MIN_SIZE - 3) && (i <= SBUILD_ID_SIZE - 3) &&
448 (d->d_name[i] == '\0');
449}
450
451struct strlist *build_id_cache__list_all(bool validonly)
452{
453 struct strlist *toplist, *linklist = NULL, *bidlist;
454 struct str_node *nd, *nd2;
455 char *topdir, *linkdir = NULL;
456 char sbuild_id[SBUILD_ID_SIZE];
457
458 /* for filename__ functions */
459 if (validonly)
460 symbol__init(NULL);
461
462 /* Open the top-level directory */
463 if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
464 return NULL;
465
466 bidlist = strlist__new(NULL, NULL);
467 if (!bidlist)
468 goto out;
469
470 toplist = lsdir(topdir, lsdir_bid_head_filter);
471 if (!toplist) {
472 pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
473 /* If there is no buildid cache, return an empty list */
474 if (errno == ENOENT)
475 goto out;
476 goto err_out;
477 }
478
479 strlist__for_each_entry(nd, toplist) {
480 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
481 goto err_out;
482 /* Open the lower-level directory */
483 linklist = lsdir(linkdir, lsdir_bid_tail_filter);
484 if (!linklist) {
485 pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
486 goto err_out;
487 }
488 strlist__for_each_entry(nd2, linklist) {
489 if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
490 nd->s, nd2->s) > SBUILD_ID_SIZE - 1)
491 goto err_out;
492 if (validonly && !build_id_cache__valid_id(sbuild_id))
493 continue;
494 if (strlist__add(bidlist, sbuild_id) < 0)
495 goto err_out;
496 }
497 strlist__delete(linklist);
498 zfree(&linkdir);
499 }
500
501out_free:
502 strlist__delete(toplist);
503out:
504 free(topdir);
505
506 return bidlist;
507
508err_out:
509 strlist__delete(linklist);
510 zfree(&linkdir);
511 strlist__delete(bidlist);
512 bidlist = NULL;
513 goto out_free;
514}
515
516static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
517{
518 size_t i;
519
520 for (i = 0; i < len; i++) {
521 if (!isxdigit(maybe_sbuild_id[i]))
522 return false;
523 }
524 return true;
525}
526
527/* Return the valid complete build-id */
528char *build_id_cache__complement(const char *incomplete_sbuild_id)
529{
530 struct strlist *bidlist;
531 struct str_node *nd, *cand = NULL;
532 char *sbuild_id = NULL;
533 size_t len = strlen(incomplete_sbuild_id);
534
535 if (len >= SBUILD_ID_SIZE ||
536 !str_is_build_id(incomplete_sbuild_id, len))
537 return NULL;
538
539 bidlist = build_id_cache__list_all(true);
540 if (!bidlist)
541 return NULL;
542
543 strlist__for_each_entry(nd, bidlist) {
544 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
545 continue;
546 if (cand) { /* Error: There are more than 2 candidates. */
547 cand = NULL;
548 break;
549 }
550 cand = nd;
551 }
552 if (cand)
553 sbuild_id = strdup(cand->s);
554 strlist__delete(bidlist);
555
556 return sbuild_id;
557}
558
559char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
560 struct nsinfo *nsi, bool is_kallsyms,
561 bool is_vdso)
562{
563 char *realname = NULL, *filename;
564 bool slash = is_kallsyms || is_vdso;
565
566 if (!slash)
567 realname = nsinfo__realpath(name, nsi);
568
569 if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
570 is_vdso ? DSO__NAME_VDSO : (realname ? realname : name),
571 sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
572 filename = NULL;
573
574 free(realname);
575 return filename;
576}
577
578int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi,
579 struct strlist **result)
580{
581 char *dir_name;
582 int ret = 0;
583
584 dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false);
585 if (!dir_name)
586 return -ENOMEM;
587
588 *result = lsdir(dir_name, lsdir_no_dot_filter);
589 if (!*result)
590 ret = -errno;
591 free(dir_name);
592
593 return ret;
594}
595
596#if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
597static int build_id_cache__add_sdt_cache(const char *sbuild_id,
598 const char *realname,
599 struct nsinfo *nsi)
600{
601 struct probe_cache *cache;
602 int ret;
603 struct nscookie nsc;
604
605 cache = probe_cache__new(sbuild_id, nsi);
606 if (!cache)
607 return -1;
608
609 nsinfo__mountns_enter(nsi, &nsc);
610 ret = probe_cache__scan_sdt(cache, realname);
611 nsinfo__mountns_exit(&nsc);
612 if (ret >= 0) {
613 pr_debug4("Found %d SDTs in %s\n", ret, realname);
614 if (probe_cache__commit(cache) < 0)
615 ret = -1;
616 }
617 probe_cache__delete(cache);
618 return ret;
619}
620#else
621#define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0)
622#endif
623
624static char *build_id_cache__find_debug(const char *sbuild_id,
625 struct nsinfo *nsi,
626 const char *root_dir)
627{
628 const char *dirname = "/usr/lib/debug/.build-id/";
629 char *realname = NULL;
630 char dirbuf[PATH_MAX];
631 char *debugfile;
632 struct nscookie nsc;
633 size_t len = 0;
634
635 debugfile = calloc(1, PATH_MAX);
636 if (!debugfile)
637 goto out;
638
639 if (root_dir) {
640 path__join(dirbuf, PATH_MAX, root_dir, dirname);
641 dirname = dirbuf;
642 }
643
644 len = __symbol__join_symfs(debugfile, PATH_MAX, dirname);
645 snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id,
646 sbuild_id + 2);
647
648 nsinfo__mountns_enter(nsi, &nsc);
649 realname = realpath(debugfile, NULL);
650 if (realname && access(realname, R_OK))
651 zfree(&realname);
652 nsinfo__mountns_exit(&nsc);
653
654#ifdef HAVE_DEBUGINFOD_SUPPORT
655 if (realname == NULL) {
656 debuginfod_client* c;
657
658 pr_debug("Downloading debug info with build id %s\n", sbuild_id);
659
660 c = debuginfod_begin();
661 if (c != NULL) {
662 int fd = debuginfod_find_debuginfo(c,
663 (const unsigned char*)sbuild_id, 0,
664 &realname);
665 if (fd >= 0)
666 close(fd); /* retaining reference by realname */
667 debuginfod_end(c);
668 }
669 }
670#endif
671
672out:
673 free(debugfile);
674 return realname;
675}
676
677int
678build_id_cache__add(const char *sbuild_id, const char *name, const char *realname,
679 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso,
680 const char *proper_name, const char *root_dir)
681{
682 const size_t size = PATH_MAX;
683 char *filename = NULL, *dir_name = NULL, *linkname = zalloc(size), *tmp;
684 char *debugfile = NULL;
685 int err = -1;
686
687 if (!proper_name)
688 proper_name = name;
689
690 dir_name = build_id_cache__cachedir(sbuild_id, proper_name, nsi, is_kallsyms,
691 is_vdso);
692 if (!dir_name)
693 goto out_free;
694
695 /* Remove old style build-id cache */
696 if (is_regular_file(dir_name))
697 if (unlink(dir_name))
698 goto out_free;
699
700 if (mkdir_p(dir_name, 0755))
701 goto out_free;
702
703 /* Save the allocated buildid dirname */
704 if (asprintf(&filename, "%s/%s", dir_name,
705 build_id_cache__basename(is_kallsyms, is_vdso,
706 false)) < 0) {
707 filename = NULL;
708 goto out_free;
709 }
710
711 if (access(filename, F_OK)) {
712 if (is_kallsyms) {
713 if (copyfile("/proc/kallsyms", filename))
714 goto out_free;
715 } else if (nsi && nsinfo__need_setns(nsi)) {
716 if (copyfile_ns(name, filename, nsi))
717 goto out_free;
718 } else if (link(realname, filename) && errno != EEXIST) {
719 struct stat f_stat;
720
721 if (!(stat(name, &f_stat) < 0) &&
722 copyfile_mode(name, filename, f_stat.st_mode))
723 goto out_free;
724 }
725 }
726
727 /* Some binaries are stripped, but have .debug files with their symbol
728 * table. Check to see if we can locate one of those, since the elf
729 * file itself may not be very useful to users of our tools without a
730 * symtab.
731 */
732 if (!is_kallsyms && !is_vdso &&
733 strncmp(".ko", name + strlen(name) - 3, 3)) {
734 debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir);
735 if (debugfile) {
736 zfree(&filename);
737 if (asprintf(&filename, "%s/%s", dir_name,
738 build_id_cache__basename(false, false, true)) < 0) {
739 filename = NULL;
740 goto out_free;
741 }
742 if (access(filename, F_OK)) {
743 if (nsi && nsinfo__need_setns(nsi)) {
744 if (copyfile_ns(debugfile, filename,
745 nsi))
746 goto out_free;
747 } else if (link(debugfile, filename) &&
748 errno != EEXIST &&
749 copyfile(debugfile, filename))
750 goto out_free;
751 }
752 }
753 }
754
755 if (!build_id_cache__linkname(sbuild_id, linkname, size))
756 goto out_free;
757 tmp = strrchr(linkname, '/');
758 *tmp = '\0';
759
760 if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
761 goto out_free;
762
763 *tmp = '/';
764 tmp = dir_name + strlen(buildid_dir) - 5;
765 memcpy(tmp, "../..", 5);
766
767 if (symlink(tmp, linkname) == 0) {
768 err = 0;
769 } else if (errno == EEXIST) {
770 char path[PATH_MAX];
771 ssize_t len;
772
773 len = readlink(linkname, path, sizeof(path) - 1);
774 if (len <= 0) {
775 pr_err("Can't read link: %s\n", linkname);
776 goto out_free;
777 }
778 path[len] = '\0';
779
780 if (strcmp(tmp, path)) {
781 pr_debug("build <%s> already linked to %s\n",
782 sbuild_id, linkname);
783 }
784 err = 0;
785 }
786
787 /* Update SDT cache : error is just warned */
788 if (realname &&
789 build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0)
790 pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
791
792out_free:
793 free(filename);
794 free(debugfile);
795 free(dir_name);
796 free(linkname);
797 return err;
798}
799
800int __build_id_cache__add_s(const char *sbuild_id, const char *name,
801 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso,
802 const char *proper_name, const char *root_dir)
803{
804 char *realname = NULL;
805 int err = -1;
806
807 if (!is_kallsyms) {
808 if (!is_vdso)
809 realname = nsinfo__realpath(name, nsi);
810 else
811 realname = realpath(name, NULL);
812 if (!realname)
813 goto out_free;
814 }
815
816 err = build_id_cache__add(sbuild_id, name, realname, nsi,
817 is_kallsyms, is_vdso, proper_name, root_dir);
818out_free:
819 if (!is_kallsyms)
820 free(realname);
821 return err;
822}
823
824static int build_id_cache__add_b(const struct build_id *bid,
825 const char *name, struct nsinfo *nsi,
826 bool is_kallsyms, bool is_vdso,
827 const char *proper_name,
828 const char *root_dir)
829{
830 char sbuild_id[SBUILD_ID_SIZE];
831
832 build_id__sprintf(bid, sbuild_id);
833
834 return __build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms,
835 is_vdso, proper_name, root_dir);
836}
837
838bool build_id_cache__cached(const char *sbuild_id)
839{
840 bool ret = false;
841 char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
842
843 if (filename && !access(filename, F_OK))
844 ret = true;
845 free(filename);
846
847 return ret;
848}
849
850int build_id_cache__remove_s(const char *sbuild_id)
851{
852 const size_t size = PATH_MAX;
853 char *filename = zalloc(size),
854 *linkname = zalloc(size), *tmp;
855 int err = -1;
856
857 if (filename == NULL || linkname == NULL)
858 goto out_free;
859
860 if (!build_id_cache__linkname(sbuild_id, linkname, size))
861 goto out_free;
862
863 if (access(linkname, F_OK))
864 goto out_free;
865
866 if (readlink(linkname, filename, size - 1) < 0)
867 goto out_free;
868
869 if (unlink(linkname))
870 goto out_free;
871
872 /*
873 * Since the link is relative, we must make it absolute:
874 */
875 tmp = strrchr(linkname, '/') + 1;
876 snprintf(tmp, size - (tmp - linkname), "%s", filename);
877
878 if (rm_rf(linkname))
879 goto out_free;
880
881 err = 0;
882out_free:
883 free(filename);
884 free(linkname);
885 return err;
886}
887
888static int filename__read_build_id_ns(const char *filename,
889 struct build_id *bid,
890 struct nsinfo *nsi)
891{
892 struct nscookie nsc;
893 int ret;
894
895 nsinfo__mountns_enter(nsi, &nsc);
896 ret = filename__read_build_id(filename, bid);
897 nsinfo__mountns_exit(&nsc);
898
899 return ret;
900}
901
902static bool dso__build_id_mismatch(struct dso *dso, const char *name)
903{
904 struct build_id bid;
905 bool ret = false;
906
907 mutex_lock(&dso->lock);
908 if (filename__read_build_id_ns(name, &bid, dso->nsinfo) >= 0)
909 ret = !dso__build_id_equal(dso, &bid);
910
911 mutex_unlock(&dso->lock);
912
913 return ret;
914}
915
916static int dso__cache_build_id(struct dso *dso, struct machine *machine,
917 void *priv __maybe_unused)
918{
919 bool is_kallsyms = dso__is_kallsyms(dso);
920 bool is_vdso = dso__is_vdso(dso);
921 const char *name = dso->long_name;
922 const char *proper_name = NULL;
923 const char *root_dir = NULL;
924 char *allocated_name = NULL;
925 int ret = 0;
926
927 if (!dso->has_build_id)
928 return 0;
929
930 if (dso__is_kcore(dso)) {
931 is_kallsyms = true;
932 name = machine->mmap_name;
933 }
934
935 if (!machine__is_host(machine)) {
936 if (*machine->root_dir) {
937 root_dir = machine->root_dir;
938 ret = asprintf(&allocated_name, "%s/%s", root_dir, name);
939 if (ret < 0)
940 return ret;
941 proper_name = name;
942 name = allocated_name;
943 } else if (is_kallsyms) {
944 /* Cannot get guest kallsyms */
945 return 0;
946 }
947 }
948
949 if (!is_kallsyms && dso__build_id_mismatch(dso, name))
950 goto out_free;
951
952 mutex_lock(&dso->lock);
953 ret = build_id_cache__add_b(&dso->bid, name, dso->nsinfo,
954 is_kallsyms, is_vdso, proper_name, root_dir);
955 mutex_unlock(&dso->lock);
956out_free:
957 free(allocated_name);
958 return ret;
959}
960
961static int
962machines__for_each_dso(struct machines *machines, machine__dso_t fn, void *priv)
963{
964 int ret = machine__for_each_dso(&machines->host, fn, priv);
965 struct rb_node *nd;
966
967 for (nd = rb_first_cached(&machines->guests); nd;
968 nd = rb_next(nd)) {
969 struct machine *pos = rb_entry(nd, struct machine, rb_node);
970
971 ret |= machine__for_each_dso(pos, fn, priv);
972 }
973 return ret ? -1 : 0;
974}
975
976int __perf_session__cache_build_ids(struct perf_session *session,
977 machine__dso_t fn, void *priv)
978{
979 if (no_buildid_cache)
980 return 0;
981
982 if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
983 return -1;
984
985 return machines__for_each_dso(&session->machines, fn, priv) ? -1 : 0;
986}
987
988int perf_session__cache_build_ids(struct perf_session *session)
989{
990 return __perf_session__cache_build_ids(session, dso__cache_build_id, NULL);
991}
992
993static bool machine__read_build_ids(struct machine *machine, bool with_hits)
994{
995 return __dsos__read_build_ids(&machine->dsos.head, with_hits);
996}
997
998bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
999{
1000 struct rb_node *nd;
1001 bool ret = machine__read_build_ids(&session->machines.host, with_hits);
1002
1003 for (nd = rb_first_cached(&session->machines.guests); nd;
1004 nd = rb_next(nd)) {
1005 struct machine *pos = rb_entry(nd, struct machine, rb_node);
1006 ret |= machine__read_build_ids(pos, with_hits);
1007 }
1008
1009 return ret;
1010}
1011
1012void build_id__init(struct build_id *bid, const u8 *data, size_t size)
1013{
1014 WARN_ON(size > BUILD_ID_SIZE);
1015 memcpy(bid->data, data, size);
1016 bid->size = size;
1017}
1018
1019bool build_id__is_defined(const struct build_id *bid)
1020{
1021 return bid && bid->size ? !!memchr_inv(bid->data, 0, bid->size) : false;
1022}