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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#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(const 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 dso__set_hit(map__dso(al.map));
64
65 addr_location__exit(&al);
66 thread__put(thread);
67 return 0;
68}
69
70int build_id__sprintf(const struct build_id *build_id, char *bf)
71{
72 char *bid = bf;
73 const u8 *raw = build_id->data;
74 size_t i;
75
76 bf[0] = 0x0;
77
78 for (i = 0; i < build_id->size; ++i) {
79 sprintf(bid, "%02x", *raw);
80 ++raw;
81 bid += 2;
82 }
83
84 return (bid - bf) + 1;
85}
86
87int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
88{
89 char notes[PATH_MAX];
90 struct build_id bid;
91 int ret;
92
93 if (!root_dir)
94 root_dir = "";
95
96 scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
97
98 ret = sysfs__read_build_id(notes, &bid);
99 if (ret < 0)
100 return ret;
101
102 return build_id__sprintf(&bid, sbuild_id);
103}
104
105int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
106{
107 struct build_id bid;
108 int ret;
109
110 ret = filename__read_build_id(pathname, &bid);
111 if (ret < 0)
112 return ret;
113
114 return build_id__sprintf(&bid, sbuild_id);
115}
116
117/* asnprintf consolidates asprintf and snprintf */
118static int asnprintf(char **strp, size_t size, const char *fmt, ...)
119{
120 va_list ap;
121 int ret;
122
123 if (!strp)
124 return -EINVAL;
125
126 va_start(ap, fmt);
127 if (*strp)
128 ret = vsnprintf(*strp, size, fmt, ap);
129 else
130 ret = vasprintf(strp, fmt, ap);
131 va_end(ap);
132
133 return ret;
134}
135
136char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
137 size_t size)
138{
139 bool retry_old = true;
140
141 snprintf(bf, size, "%s/%s/%s/kallsyms",
142 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
143retry:
144 if (!access(bf, F_OK))
145 return bf;
146 if (retry_old) {
147 /* Try old style kallsyms cache */
148 snprintf(bf, size, "%s/%s/%s",
149 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
150 retry_old = false;
151 goto retry;
152 }
153
154 return NULL;
155}
156
157char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size)
158{
159 char *tmp = bf;
160 int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
161 sbuild_id, sbuild_id + 2);
162 if (ret < 0 || (tmp && size < (unsigned int)ret))
163 return NULL;
164 return bf;
165}
166
167/* The caller is responsible to free the returned buffer. */
168char *build_id_cache__origname(const char *sbuild_id)
169{
170 char *linkname;
171 char buf[PATH_MAX];
172 char *ret = NULL, *p;
173 size_t offs = 5; /* == strlen("../..") */
174 ssize_t len;
175
176 linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
177 if (!linkname)
178 return NULL;
179
180 len = readlink(linkname, buf, sizeof(buf) - 1);
181 if (len <= 0)
182 goto out;
183 buf[len] = '\0';
184
185 /* The link should be "../..<origpath>/<sbuild_id>" */
186 p = strrchr(buf, '/'); /* Cut off the "/<sbuild_id>" */
187 if (p && (p > buf + offs)) {
188 *p = '\0';
189 if (buf[offs + 1] == '[')
190 offs++; /*
191 * This is a DSO name, like [kernel.kallsyms].
192 * Skip the first '/', since this is not the
193 * cache of a regular file.
194 */
195 ret = strdup(buf + offs); /* Skip "../..[/]" */
196 }
197out:
198 free(linkname);
199 return ret;
200}
201
202/* Check if the given build_id cache is valid on current running system */
203static bool build_id_cache__valid_id(char *sbuild_id)
204{
205 char real_sbuild_id[SBUILD_ID_SIZE] = "";
206 char *pathname;
207 int ret = 0;
208 bool result = false;
209
210 pathname = build_id_cache__origname(sbuild_id);
211 if (!pathname)
212 return false;
213
214 if (!strcmp(pathname, DSO__NAME_KALLSYMS))
215 ret = sysfs__sprintf_build_id("/", real_sbuild_id);
216 else if (pathname[0] == '/')
217 ret = filename__sprintf_build_id(pathname, real_sbuild_id);
218 else
219 ret = -EINVAL; /* Should we support other special DSO cache? */
220 if (ret >= 0)
221 result = (strcmp(sbuild_id, real_sbuild_id) == 0);
222 free(pathname);
223
224 return result;
225}
226
227static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
228 bool is_debug)
229{
230 return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
231 "debug" : "elf"));
232}
233
234char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
235 bool is_debug, bool is_kallsyms)
236{
237 bool is_vdso = dso__is_vdso((struct dso *)dso);
238 char sbuild_id[SBUILD_ID_SIZE];
239 char *linkname;
240 bool alloc = (bf == NULL);
241 int ret;
242
243 if (!dso__has_build_id(dso))
244 return NULL;
245
246 build_id__sprintf(dso__bid_const(dso), sbuild_id);
247 linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
248 if (!linkname)
249 return NULL;
250
251 /* Check if old style build_id cache */
252 if (is_regular_file(linkname))
253 ret = asnprintf(&bf, size, "%s", linkname);
254 else
255 ret = asnprintf(&bf, size, "%s/%s", linkname,
256 build_id_cache__basename(is_kallsyms, is_vdso,
257 is_debug));
258 if (ret < 0 || (!alloc && size < (unsigned int)ret))
259 bf = NULL;
260 free(linkname);
261
262 return bf;
263}
264
265char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
266 bool is_debug)
267{
268 bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
269
270 return __dso__build_id_filename(dso, bf, size, is_debug, is_kallsyms);
271}
272
273static int write_buildid(const char *name, size_t name_len, struct build_id *bid,
274 pid_t pid, u16 misc, struct feat_fd *fd)
275{
276 int err;
277 struct perf_record_header_build_id b;
278 size_t len;
279
280 len = name_len + 1;
281 len = PERF_ALIGN(len, sizeof(u64));
282
283 memset(&b, 0, sizeof(b));
284 memcpy(&b.data, bid->data, bid->size);
285 b.size = (u8) bid->size;
286 misc |= PERF_RECORD_MISC_BUILD_ID_SIZE;
287 b.pid = pid;
288 b.header.misc = misc;
289 b.header.size = sizeof(b) + len;
290
291 err = do_write(fd, &b, sizeof(b));
292 if (err < 0)
293 return err;
294
295 return write_padded(fd, name, name_len + 1, len);
296}
297
298struct machine__write_buildid_table_cb_args {
299 struct machine *machine;
300 struct feat_fd *fd;
301 u16 kmisc, umisc;
302};
303
304static int machine__write_buildid_table_cb(struct dso *dso, void *data)
305{
306 struct machine__write_buildid_table_cb_args *args = data;
307 const char *name;
308 size_t name_len;
309 bool in_kernel = false;
310
311 if (!dso__has_build_id(dso))
312 return 0;
313
314 if (!dso__hit(dso) && !dso__is_vdso(dso))
315 return 0;
316
317 if (dso__is_vdso(dso)) {
318 name = dso__short_name(dso);
319 name_len = dso__short_name_len(dso);
320 } else if (dso__is_kcore(dso)) {
321 name = args->machine->mmap_name;
322 name_len = strlen(name);
323 } else {
324 name = dso__long_name(dso);
325 name_len = dso__long_name_len(dso);
326 }
327
328 in_kernel = dso__kernel(dso) || is_kernel_module(name, PERF_RECORD_MISC_CPUMODE_UNKNOWN);
329 return write_buildid(name, name_len, dso__bid(dso), args->machine->pid,
330 in_kernel ? args->kmisc : args->umisc, args->fd);
331}
332
333static int machine__write_buildid_table(struct machine *machine, struct feat_fd *fd)
334{
335 struct machine__write_buildid_table_cb_args args = {
336 .machine = machine,
337 .fd = fd,
338 .kmisc = PERF_RECORD_MISC_KERNEL,
339 .umisc = PERF_RECORD_MISC_USER,
340 };
341
342 if (!machine__is_host(machine)) {
343 args.kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
344 args.umisc = PERF_RECORD_MISC_GUEST_USER;
345 }
346
347 return dsos__for_each_dso(&machine->dsos, machine__write_buildid_table_cb, &args);
348}
349
350int perf_session__write_buildid_table(struct perf_session *session,
351 struct feat_fd *fd)
352{
353 struct rb_node *nd;
354 int err = machine__write_buildid_table(&session->machines.host, fd);
355
356 if (err)
357 return err;
358
359 for (nd = rb_first_cached(&session->machines.guests); nd;
360 nd = rb_next(nd)) {
361 struct machine *pos = rb_entry(nd, struct machine, rb_node);
362 err = machine__write_buildid_table(pos, fd);
363 if (err)
364 break;
365 }
366 return err;
367}
368
369void disable_buildid_cache(void)
370{
371 no_buildid_cache = true;
372}
373
374static bool lsdir_bid_head_filter(const char *name __maybe_unused,
375 struct dirent *d)
376{
377 return (strlen(d->d_name) == 2) &&
378 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
379}
380
381static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
382 struct dirent *d)
383{
384 int i = 0;
385 while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
386 i++;
387 return (i >= SBUILD_ID_MIN_SIZE - 3) && (i <= SBUILD_ID_SIZE - 3) &&
388 (d->d_name[i] == '\0');
389}
390
391struct strlist *build_id_cache__list_all(bool validonly)
392{
393 struct strlist *toplist, *linklist = NULL, *bidlist;
394 struct str_node *nd, *nd2;
395 char *topdir, *linkdir = NULL;
396 char sbuild_id[SBUILD_ID_SIZE];
397
398 /* for filename__ functions */
399 if (validonly)
400 symbol__init(NULL);
401
402 /* Open the top-level directory */
403 if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
404 return NULL;
405
406 bidlist = strlist__new(NULL, NULL);
407 if (!bidlist)
408 goto out;
409
410 toplist = lsdir(topdir, lsdir_bid_head_filter);
411 if (!toplist) {
412 pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
413 /* If there is no buildid cache, return an empty list */
414 if (errno == ENOENT)
415 goto out;
416 goto err_out;
417 }
418
419 strlist__for_each_entry(nd, toplist) {
420 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
421 goto err_out;
422 /* Open the lower-level directory */
423 linklist = lsdir(linkdir, lsdir_bid_tail_filter);
424 if (!linklist) {
425 pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
426 goto err_out;
427 }
428 strlist__for_each_entry(nd2, linklist) {
429 if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
430 nd->s, nd2->s) > SBUILD_ID_SIZE - 1)
431 goto err_out;
432 if (validonly && !build_id_cache__valid_id(sbuild_id))
433 continue;
434 if (strlist__add(bidlist, sbuild_id) < 0)
435 goto err_out;
436 }
437 strlist__delete(linklist);
438 zfree(&linkdir);
439 }
440
441out_free:
442 strlist__delete(toplist);
443out:
444 free(topdir);
445
446 return bidlist;
447
448err_out:
449 strlist__delete(linklist);
450 zfree(&linkdir);
451 strlist__delete(bidlist);
452 bidlist = NULL;
453 goto out_free;
454}
455
456static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
457{
458 size_t i;
459
460 for (i = 0; i < len; i++) {
461 if (!isxdigit(maybe_sbuild_id[i]))
462 return false;
463 }
464 return true;
465}
466
467/* Return the valid complete build-id */
468char *build_id_cache__complement(const char *incomplete_sbuild_id)
469{
470 struct strlist *bidlist;
471 struct str_node *nd, *cand = NULL;
472 char *sbuild_id = NULL;
473 size_t len = strlen(incomplete_sbuild_id);
474
475 if (len >= SBUILD_ID_SIZE ||
476 !str_is_build_id(incomplete_sbuild_id, len))
477 return NULL;
478
479 bidlist = build_id_cache__list_all(true);
480 if (!bidlist)
481 return NULL;
482
483 strlist__for_each_entry(nd, bidlist) {
484 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
485 continue;
486 if (cand) { /* Error: There are more than 2 candidates. */
487 cand = NULL;
488 break;
489 }
490 cand = nd;
491 }
492 if (cand)
493 sbuild_id = strdup(cand->s);
494 strlist__delete(bidlist);
495
496 return sbuild_id;
497}
498
499char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
500 struct nsinfo *nsi, bool is_kallsyms,
501 bool is_vdso)
502{
503 char *realname = NULL, *filename;
504 bool slash = is_kallsyms || is_vdso;
505
506 if (!slash)
507 realname = nsinfo__realpath(name, nsi);
508
509 if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
510 is_vdso ? DSO__NAME_VDSO : (realname ? realname : name),
511 sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
512 filename = NULL;
513
514 free(realname);
515 return filename;
516}
517
518int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi,
519 struct strlist **result)
520{
521 char *dir_name;
522 int ret = 0;
523
524 dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false);
525 if (!dir_name)
526 return -ENOMEM;
527
528 *result = lsdir(dir_name, lsdir_no_dot_filter);
529 if (!*result)
530 ret = -errno;
531 free(dir_name);
532
533 return ret;
534}
535
536#if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
537static int build_id_cache__add_sdt_cache(const char *sbuild_id,
538 const char *realname,
539 struct nsinfo *nsi)
540{
541 struct probe_cache *cache;
542 int ret;
543 struct nscookie nsc;
544
545 cache = probe_cache__new(sbuild_id, nsi);
546 if (!cache)
547 return -1;
548
549 nsinfo__mountns_enter(nsi, &nsc);
550 ret = probe_cache__scan_sdt(cache, realname);
551 nsinfo__mountns_exit(&nsc);
552 if (ret >= 0) {
553 pr_debug4("Found %d SDTs in %s\n", ret, realname);
554 if (probe_cache__commit(cache) < 0)
555 ret = -1;
556 }
557 probe_cache__delete(cache);
558 return ret;
559}
560#else
561#define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0)
562#endif
563
564static char *build_id_cache__find_debug(const char *sbuild_id,
565 struct nsinfo *nsi,
566 const char *root_dir)
567{
568 const char *dirname = "/usr/lib/debug/.build-id/";
569 char *realname = NULL;
570 char dirbuf[PATH_MAX];
571 char *debugfile;
572 struct nscookie nsc;
573 size_t len = 0;
574
575 debugfile = calloc(1, PATH_MAX);
576 if (!debugfile)
577 goto out;
578
579 if (root_dir) {
580 path__join(dirbuf, PATH_MAX, root_dir, dirname);
581 dirname = dirbuf;
582 }
583
584 len = __symbol__join_symfs(debugfile, PATH_MAX, dirname);
585 snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id,
586 sbuild_id + 2);
587
588 nsinfo__mountns_enter(nsi, &nsc);
589 realname = realpath(debugfile, NULL);
590 if (realname && access(realname, R_OK))
591 zfree(&realname);
592 nsinfo__mountns_exit(&nsc);
593
594#ifdef HAVE_DEBUGINFOD_SUPPORT
595 if (realname == NULL) {
596 debuginfod_client* c;
597
598 pr_debug("Downloading debug info with build id %s\n", sbuild_id);
599
600 c = debuginfod_begin();
601 if (c != NULL) {
602 int fd = debuginfod_find_debuginfo(c,
603 (const unsigned char*)sbuild_id, 0,
604 &realname);
605 if (fd >= 0)
606 close(fd); /* retaining reference by realname */
607 debuginfod_end(c);
608 }
609 }
610#endif
611
612out:
613 free(debugfile);
614 return realname;
615}
616
617int
618build_id_cache__add(const char *sbuild_id, const char *name, const char *realname,
619 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso,
620 const char *proper_name, const char *root_dir)
621{
622 const size_t size = PATH_MAX;
623 char *filename = NULL, *dir_name = NULL, *linkname = zalloc(size), *tmp;
624 char *debugfile = NULL;
625 int err = -1;
626
627 if (!proper_name)
628 proper_name = name;
629
630 dir_name = build_id_cache__cachedir(sbuild_id, proper_name, nsi, is_kallsyms,
631 is_vdso);
632 if (!dir_name)
633 goto out_free;
634
635 /* Remove old style build-id cache */
636 if (is_regular_file(dir_name))
637 if (unlink(dir_name))
638 goto out_free;
639
640 if (mkdir_p(dir_name, 0755))
641 goto out_free;
642
643 /* Save the allocated buildid dirname */
644 if (asprintf(&filename, "%s/%s", dir_name,
645 build_id_cache__basename(is_kallsyms, is_vdso,
646 false)) < 0) {
647 filename = NULL;
648 goto out_free;
649 }
650
651 if (access(filename, F_OK)) {
652 if (is_kallsyms) {
653 if (copyfile("/proc/kallsyms", filename))
654 goto out_free;
655 } else if (nsi && nsinfo__need_setns(nsi)) {
656 if (copyfile_ns(name, filename, nsi))
657 goto out_free;
658 } else if (link(realname, filename) && errno != EEXIST) {
659 struct stat f_stat;
660
661 if (!(stat(name, &f_stat) < 0) &&
662 copyfile_mode(name, filename, f_stat.st_mode))
663 goto out_free;
664 }
665 }
666
667 /* Some binaries are stripped, but have .debug files with their symbol
668 * table. Check to see if we can locate one of those, since the elf
669 * file itself may not be very useful to users of our tools without a
670 * symtab.
671 */
672 if (!is_kallsyms && !is_vdso &&
673 strncmp(".ko", name + strlen(name) - 3, 3)) {
674 debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir);
675 if (debugfile) {
676 zfree(&filename);
677 if (asprintf(&filename, "%s/%s", dir_name,
678 build_id_cache__basename(false, false, true)) < 0) {
679 filename = NULL;
680 goto out_free;
681 }
682 if (access(filename, F_OK)) {
683 if (nsi && nsinfo__need_setns(nsi)) {
684 if (copyfile_ns(debugfile, filename,
685 nsi))
686 goto out_free;
687 } else if (link(debugfile, filename) &&
688 errno != EEXIST &&
689 copyfile(debugfile, filename))
690 goto out_free;
691 }
692 }
693 }
694
695 if (!build_id_cache__linkname(sbuild_id, linkname, size))
696 goto out_free;
697 tmp = strrchr(linkname, '/');
698 *tmp = '\0';
699
700 if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
701 goto out_free;
702
703 *tmp = '/';
704 tmp = dir_name + strlen(buildid_dir) - 5;
705 memcpy(tmp, "../..", 5);
706
707 if (symlink(tmp, linkname) == 0) {
708 err = 0;
709 } else if (errno == EEXIST) {
710 char path[PATH_MAX];
711 ssize_t len;
712
713 len = readlink(linkname, path, sizeof(path) - 1);
714 if (len <= 0) {
715 pr_err("Can't read link: %s\n", linkname);
716 goto out_free;
717 }
718 path[len] = '\0';
719
720 if (strcmp(tmp, path)) {
721 pr_debug("build <%s> already linked to %s\n",
722 sbuild_id, linkname);
723 }
724 err = 0;
725 }
726
727 /* Update SDT cache : error is just warned */
728 if (realname &&
729 build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0)
730 pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
731
732out_free:
733 free(filename);
734 free(debugfile);
735 free(dir_name);
736 free(linkname);
737 return err;
738}
739
740int __build_id_cache__add_s(const char *sbuild_id, const char *name,
741 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso,
742 const char *proper_name, const char *root_dir)
743{
744 char *realname = NULL;
745 int err = -1;
746
747 if (!is_kallsyms) {
748 if (!is_vdso)
749 realname = nsinfo__realpath(name, nsi);
750 else
751 realname = realpath(name, NULL);
752 if (!realname)
753 goto out_free;
754 }
755
756 err = build_id_cache__add(sbuild_id, name, realname, nsi,
757 is_kallsyms, is_vdso, proper_name, root_dir);
758out_free:
759 if (!is_kallsyms)
760 free(realname);
761 return err;
762}
763
764static int build_id_cache__add_b(const struct build_id *bid,
765 const char *name, struct nsinfo *nsi,
766 bool is_kallsyms, bool is_vdso,
767 const char *proper_name,
768 const char *root_dir)
769{
770 char sbuild_id[SBUILD_ID_SIZE];
771
772 build_id__sprintf(bid, sbuild_id);
773
774 return __build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms,
775 is_vdso, proper_name, root_dir);
776}
777
778bool build_id_cache__cached(const char *sbuild_id)
779{
780 bool ret = false;
781 char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
782
783 if (filename && !access(filename, F_OK))
784 ret = true;
785 free(filename);
786
787 return ret;
788}
789
790int build_id_cache__remove_s(const char *sbuild_id)
791{
792 const size_t size = PATH_MAX;
793 char *filename = zalloc(size),
794 *linkname = zalloc(size), *tmp;
795 int err = -1;
796
797 if (filename == NULL || linkname == NULL)
798 goto out_free;
799
800 if (!build_id_cache__linkname(sbuild_id, linkname, size))
801 goto out_free;
802
803 if (access(linkname, F_OK))
804 goto out_free;
805
806 if (readlink(linkname, filename, size - 1) < 0)
807 goto out_free;
808
809 if (unlink(linkname))
810 goto out_free;
811
812 /*
813 * Since the link is relative, we must make it absolute:
814 */
815 tmp = strrchr(linkname, '/') + 1;
816 snprintf(tmp, size - (tmp - linkname), "%s", filename);
817
818 if (rm_rf(linkname))
819 goto out_free;
820
821 err = 0;
822out_free:
823 free(filename);
824 free(linkname);
825 return err;
826}
827
828static int filename__read_build_id_ns(const char *filename,
829 struct build_id *bid,
830 struct nsinfo *nsi)
831{
832 struct nscookie nsc;
833 int ret;
834
835 nsinfo__mountns_enter(nsi, &nsc);
836 ret = filename__read_build_id(filename, bid);
837 nsinfo__mountns_exit(&nsc);
838
839 return ret;
840}
841
842static bool dso__build_id_mismatch(struct dso *dso, const char *name)
843{
844 struct build_id bid;
845 bool ret = false;
846
847 mutex_lock(dso__lock(dso));
848 if (filename__read_build_id_ns(name, &bid, dso__nsinfo(dso)) >= 0)
849 ret = !dso__build_id_equal(dso, &bid);
850
851 mutex_unlock(dso__lock(dso));
852
853 return ret;
854}
855
856static int dso__cache_build_id(struct dso *dso, struct machine *machine,
857 void *priv __maybe_unused)
858{
859 bool is_kallsyms = dso__is_kallsyms(dso);
860 bool is_vdso = dso__is_vdso(dso);
861 const char *name = dso__long_name(dso);
862 const char *proper_name = NULL;
863 const char *root_dir = NULL;
864 char *allocated_name = NULL;
865 int ret = 0;
866
867 if (!dso__has_build_id(dso))
868 return 0;
869
870 if (dso__is_kcore(dso)) {
871 is_kallsyms = true;
872 name = machine->mmap_name;
873 }
874
875 if (!machine__is_host(machine)) {
876 if (*machine->root_dir) {
877 root_dir = machine->root_dir;
878 ret = asprintf(&allocated_name, "%s/%s", root_dir, name);
879 if (ret < 0)
880 return ret;
881 proper_name = name;
882 name = allocated_name;
883 } else if (is_kallsyms) {
884 /* Cannot get guest kallsyms */
885 return 0;
886 }
887 }
888
889 if (!is_kallsyms && dso__build_id_mismatch(dso, name))
890 goto out_free;
891
892 mutex_lock(dso__lock(dso));
893 ret = build_id_cache__add_b(dso__bid(dso), name, dso__nsinfo(dso),
894 is_kallsyms, is_vdso, proper_name, root_dir);
895 mutex_unlock(dso__lock(dso));
896out_free:
897 free(allocated_name);
898 return ret;
899}
900
901static int
902machines__for_each_dso(struct machines *machines, machine__dso_t fn, void *priv)
903{
904 int ret = machine__for_each_dso(&machines->host, fn, priv);
905 struct rb_node *nd;
906
907 for (nd = rb_first_cached(&machines->guests); nd;
908 nd = rb_next(nd)) {
909 struct machine *pos = rb_entry(nd, struct machine, rb_node);
910
911 ret |= machine__for_each_dso(pos, fn, priv);
912 }
913 return ret ? -1 : 0;
914}
915
916int __perf_session__cache_build_ids(struct perf_session *session,
917 machine__dso_t fn, void *priv)
918{
919 if (no_buildid_cache)
920 return 0;
921
922 if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
923 return -1;
924
925 return machines__for_each_dso(&session->machines, fn, priv) ? -1 : 0;
926}
927
928int perf_session__cache_build_ids(struct perf_session *session)
929{
930 return __perf_session__cache_build_ids(session, dso__cache_build_id, NULL);
931}
932
933static bool machine__read_build_ids(struct machine *machine, bool with_hits)
934{
935 return dsos__read_build_ids(&machine->dsos, with_hits);
936}
937
938bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
939{
940 struct rb_node *nd;
941 bool ret = machine__read_build_ids(&session->machines.host, with_hits);
942
943 for (nd = rb_first_cached(&session->machines.guests); nd;
944 nd = rb_next(nd)) {
945 struct machine *pos = rb_entry(nd, struct machine, rb_node);
946 ret |= machine__read_build_ids(pos, with_hits);
947 }
948
949 return ret;
950}
951
952void build_id__init(struct build_id *bid, const u8 *data, size_t size)
953{
954 WARN_ON(size > BUILD_ID_SIZE);
955 memcpy(bid->data, data, size);
956 bid->size = size;
957}
958
959bool build_id__is_defined(const struct build_id *bid)
960{
961 return bid && bid->size ? !!memchr_inv(bid->data, 0, bid->size) : false;
962}
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}