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