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