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