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 43 static bool no_buildid_cache; 44 45 int 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 70 int 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 87 int 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 } 104 105 int 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 */ 118 static 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 } 135 136 char *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); 143 retry: 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 } 156 157 char *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. */ 168 char *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 } 197 out: 198 free(linkname); 199 return ret; 200 } 201 202 /* Check if the given build_id cache is valid on current running system */ 203 static 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 } 226 227 static 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 } 233 234 char *__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 } 264 265 char *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 } 272 273 static 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 } 297 298 struct machine__write_buildid_table_cb_args { 299 struct machine *machine; 300 struct feat_fd *fd; 301 u16 kmisc, umisc; 302 }; 303 304 static 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 } 332 333 static 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 } 349 350 int 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 } 368 369 void disable_buildid_cache(void) 370 { 371 no_buildid_cache = true; 372 } 373 374 static 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 } 380 381 static 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 } 390 391 struct 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 } 440 441 out_free: 442 strlist__delete(toplist); 443 out: 444 free(topdir); 445 446 return bidlist; 447 448 err_out: 449 strlist__delete(linklist); 450 zfree(&linkdir); 451 strlist__delete(bidlist); 452 bidlist = NULL; 453 goto out_free; 454 } 455 456 static 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 */ 468 char *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 } 498 499 char *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 } 517 518 int 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) 537 static 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 563 564 static 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 611 612 out: 613 free(debugfile); 614 return realname; 615 } 616 617 int 618 build_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); 731 732 out_free: 733 free(filename); 734 free(debugfile); 735 free(dir_name); 736 free(linkname); 737 return err; 738 } 739 740 int __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); 758 out_free: 759 if (!is_kallsyms) 760 free(realname); 761 return err; 762 } 763 764 static 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 } 777 778 bool 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 } 789 790 int 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; 822 out_free: 823 free(filename); 824 free(linkname); 825 return err; 826 } 827 828 static 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 } 841 842 static 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 } 855 856 static 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)); 896 out_free: 897 free(allocated_name); 898 return ret; 899 } 900 901 static int 902 machines__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 } 915 916 int __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 } 927 928 int perf_session__cache_build_ids(struct perf_session *session) 929 { 930 return __perf_session__cache_build_ids(session, dso__cache_build_id, NULL); 931 } 932 933 static bool machine__read_build_ids(struct machine *machine, bool with_hits) 934 { 935 return dsos__read_build_ids(&machine->dsos, with_hits); 936 } 937 938 bool 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 } 951 952 void 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 } 958 959 bool build_id__is_defined(const struct build_id *bid) 960 { 961 return bid && bid->size ? !!memchr_inv(bid->data, 0, bid->size) : false; 962 } 963