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(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 if (thread__find_map(thread, sample->cpumode, sample->ip, &al)) 62 al.map->dso->hit = 1; 63 64 thread__put(thread); 65 return 0; 66 } 67 68 static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused, 69 union perf_event *event, 70 struct perf_sample *sample 71 __maybe_unused, 72 struct machine *machine) 73 { 74 struct thread *thread = machine__findnew_thread(machine, 75 event->fork.pid, 76 event->fork.tid); 77 78 dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid, 79 event->fork.ppid, event->fork.ptid); 80 81 if (thread) { 82 machine__remove_thread(machine, thread); 83 thread__put(thread); 84 } 85 86 return 0; 87 } 88 89 struct perf_tool build_id__mark_dso_hit_ops = { 90 .sample = build_id__mark_dso_hit, 91 .mmap = perf_event__process_mmap, 92 .mmap2 = perf_event__process_mmap2, 93 .fork = perf_event__process_fork, 94 .exit = perf_event__exit_del_thread, 95 .attr = perf_event__process_attr, 96 .build_id = perf_event__process_build_id, 97 .ordered_events = true, 98 }; 99 100 int build_id__sprintf(const struct build_id *build_id, char *bf) 101 { 102 char *bid = bf; 103 const u8 *raw = build_id->data; 104 size_t i; 105 106 bf[0] = 0x0; 107 108 for (i = 0; i < build_id->size; ++i) { 109 sprintf(bid, "%02x", *raw); 110 ++raw; 111 bid += 2; 112 } 113 114 return (bid - bf) + 1; 115 } 116 117 int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id) 118 { 119 char notes[PATH_MAX]; 120 struct build_id bid; 121 int ret; 122 123 if (!root_dir) 124 root_dir = ""; 125 126 scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir); 127 128 ret = sysfs__read_build_id(notes, &bid); 129 if (ret < 0) 130 return ret; 131 132 return build_id__sprintf(&bid, sbuild_id); 133 } 134 135 int filename__sprintf_build_id(const char *pathname, char *sbuild_id) 136 { 137 struct build_id bid; 138 int ret; 139 140 ret = filename__read_build_id(pathname, &bid); 141 if (ret < 0) 142 return ret; 143 144 return build_id__sprintf(&bid, sbuild_id); 145 } 146 147 /* asnprintf consolidates asprintf and snprintf */ 148 static int asnprintf(char **strp, size_t size, const char *fmt, ...) 149 { 150 va_list ap; 151 int ret; 152 153 if (!strp) 154 return -EINVAL; 155 156 va_start(ap, fmt); 157 if (*strp) 158 ret = vsnprintf(*strp, size, fmt, ap); 159 else 160 ret = vasprintf(strp, fmt, ap); 161 va_end(ap); 162 163 return ret; 164 } 165 166 char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf, 167 size_t size) 168 { 169 bool retry_old = true; 170 171 snprintf(bf, size, "%s/%s/%s/kallsyms", 172 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); 173 retry: 174 if (!access(bf, F_OK)) 175 return bf; 176 if (retry_old) { 177 /* Try old style kallsyms cache */ 178 snprintf(bf, size, "%s/%s/%s", 179 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); 180 retry_old = false; 181 goto retry; 182 } 183 184 return NULL; 185 } 186 187 char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size) 188 { 189 char *tmp = bf; 190 int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir, 191 sbuild_id, sbuild_id + 2); 192 if (ret < 0 || (tmp && size < (unsigned int)ret)) 193 return NULL; 194 return bf; 195 } 196 197 /* The caller is responsible to free the returned buffer. */ 198 char *build_id_cache__origname(const char *sbuild_id) 199 { 200 char *linkname; 201 char buf[PATH_MAX]; 202 char *ret = NULL, *p; 203 size_t offs = 5; /* == strlen("../..") */ 204 ssize_t len; 205 206 linkname = build_id_cache__linkname(sbuild_id, NULL, 0); 207 if (!linkname) 208 return NULL; 209 210 len = readlink(linkname, buf, sizeof(buf) - 1); 211 if (len <= 0) 212 goto out; 213 buf[len] = '\0'; 214 215 /* The link should be "../..<origpath>/<sbuild_id>" */ 216 p = strrchr(buf, '/'); /* Cut off the "/<sbuild_id>" */ 217 if (p && (p > buf + offs)) { 218 *p = '\0'; 219 if (buf[offs + 1] == '[') 220 offs++; /* 221 * This is a DSO name, like [kernel.kallsyms]. 222 * Skip the first '/', since this is not the 223 * cache of a regular file. 224 */ 225 ret = strdup(buf + offs); /* Skip "../..[/]" */ 226 } 227 out: 228 free(linkname); 229 return ret; 230 } 231 232 /* Check if the given build_id cache is valid on current running system */ 233 static bool build_id_cache__valid_id(char *sbuild_id) 234 { 235 char real_sbuild_id[SBUILD_ID_SIZE] = ""; 236 char *pathname; 237 int ret = 0; 238 bool result = false; 239 240 pathname = build_id_cache__origname(sbuild_id); 241 if (!pathname) 242 return false; 243 244 if (!strcmp(pathname, DSO__NAME_KALLSYMS)) 245 ret = sysfs__sprintf_build_id("/", real_sbuild_id); 246 else if (pathname[0] == '/') 247 ret = filename__sprintf_build_id(pathname, real_sbuild_id); 248 else 249 ret = -EINVAL; /* Should we support other special DSO cache? */ 250 if (ret >= 0) 251 result = (strcmp(sbuild_id, real_sbuild_id) == 0); 252 free(pathname); 253 254 return result; 255 } 256 257 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso, 258 bool is_debug) 259 { 260 return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ? 261 "debug" : "elf")); 262 } 263 264 char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size, 265 bool is_debug, bool is_kallsyms) 266 { 267 bool is_vdso = dso__is_vdso((struct dso *)dso); 268 char sbuild_id[SBUILD_ID_SIZE]; 269 char *linkname; 270 bool alloc = (bf == NULL); 271 int ret; 272 273 if (!dso->has_build_id) 274 return NULL; 275 276 build_id__sprintf(&dso->bid, sbuild_id); 277 linkname = build_id_cache__linkname(sbuild_id, NULL, 0); 278 if (!linkname) 279 return NULL; 280 281 /* Check if old style build_id cache */ 282 if (is_regular_file(linkname)) 283 ret = asnprintf(&bf, size, "%s", linkname); 284 else 285 ret = asnprintf(&bf, size, "%s/%s", linkname, 286 build_id_cache__basename(is_kallsyms, is_vdso, 287 is_debug)); 288 if (ret < 0 || (!alloc && size < (unsigned int)ret)) 289 bf = NULL; 290 free(linkname); 291 292 return bf; 293 } 294 295 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size, 296 bool is_debug) 297 { 298 bool is_kallsyms = dso__is_kallsyms((struct dso *)dso); 299 300 return __dso__build_id_filename(dso, bf, size, is_debug, is_kallsyms); 301 } 302 303 #define dsos__for_each_with_build_id(pos, head) \ 304 list_for_each_entry(pos, head, node) \ 305 if (!pos->has_build_id) \ 306 continue; \ 307 else 308 309 static int write_buildid(const char *name, size_t name_len, struct build_id *bid, 310 pid_t pid, u16 misc, struct feat_fd *fd) 311 { 312 int err; 313 struct perf_record_header_build_id b; 314 size_t len; 315 316 len = name_len + 1; 317 len = PERF_ALIGN(len, NAME_ALIGN); 318 319 memset(&b, 0, sizeof(b)); 320 memcpy(&b.data, bid->data, bid->size); 321 b.size = (u8) bid->size; 322 misc |= PERF_RECORD_MISC_BUILD_ID_SIZE; 323 b.pid = pid; 324 b.header.misc = misc; 325 b.header.size = sizeof(b) + len; 326 327 err = do_write(fd, &b, sizeof(b)); 328 if (err < 0) 329 return err; 330 331 return write_padded(fd, name, name_len + 1, len); 332 } 333 334 static int machine__write_buildid_table(struct machine *machine, 335 struct feat_fd *fd) 336 { 337 int err = 0; 338 struct dso *pos; 339 u16 kmisc = PERF_RECORD_MISC_KERNEL, 340 umisc = PERF_RECORD_MISC_USER; 341 342 if (!machine__is_host(machine)) { 343 kmisc = PERF_RECORD_MISC_GUEST_KERNEL; 344 umisc = PERF_RECORD_MISC_GUEST_USER; 345 } 346 347 dsos__for_each_with_build_id(pos, &machine->dsos.head) { 348 const char *name; 349 size_t name_len; 350 bool in_kernel = false; 351 352 if (!pos->hit && !dso__is_vdso(pos)) 353 continue; 354 355 if (dso__is_vdso(pos)) { 356 name = pos->short_name; 357 name_len = pos->short_name_len; 358 } else if (dso__is_kcore(pos)) { 359 name = machine->mmap_name; 360 name_len = strlen(name); 361 } else { 362 name = pos->long_name; 363 name_len = pos->long_name_len; 364 } 365 366 in_kernel = pos->kernel || 367 is_kernel_module(name, 368 PERF_RECORD_MISC_CPUMODE_UNKNOWN); 369 err = write_buildid(name, name_len, &pos->bid, machine->pid, 370 in_kernel ? kmisc : umisc, fd); 371 if (err) 372 break; 373 } 374 375 return err; 376 } 377 378 int perf_session__write_buildid_table(struct perf_session *session, 379 struct feat_fd *fd) 380 { 381 struct rb_node *nd; 382 int err = machine__write_buildid_table(&session->machines.host, fd); 383 384 if (err) 385 return err; 386 387 for (nd = rb_first_cached(&session->machines.guests); nd; 388 nd = rb_next(nd)) { 389 struct machine *pos = rb_entry(nd, struct machine, rb_node); 390 err = machine__write_buildid_table(pos, fd); 391 if (err) 392 break; 393 } 394 return err; 395 } 396 397 static int __dsos__hit_all(struct list_head *head) 398 { 399 struct dso *pos; 400 401 list_for_each_entry(pos, head, node) 402 pos->hit = true; 403 404 return 0; 405 } 406 407 static int machine__hit_all_dsos(struct machine *machine) 408 { 409 return __dsos__hit_all(&machine->dsos.head); 410 } 411 412 int dsos__hit_all(struct perf_session *session) 413 { 414 struct rb_node *nd; 415 int err; 416 417 err = machine__hit_all_dsos(&session->machines.host); 418 if (err) 419 return err; 420 421 for (nd = rb_first_cached(&session->machines.guests); nd; 422 nd = rb_next(nd)) { 423 struct machine *pos = rb_entry(nd, struct machine, rb_node); 424 425 err = machine__hit_all_dsos(pos); 426 if (err) 427 return err; 428 } 429 430 return 0; 431 } 432 433 void disable_buildid_cache(void) 434 { 435 no_buildid_cache = true; 436 } 437 438 static bool lsdir_bid_head_filter(const char *name __maybe_unused, 439 struct dirent *d) 440 { 441 return (strlen(d->d_name) == 2) && 442 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]); 443 } 444 445 static bool lsdir_bid_tail_filter(const char *name __maybe_unused, 446 struct dirent *d) 447 { 448 int i = 0; 449 while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3) 450 i++; 451 return (i >= SBUILD_ID_MIN_SIZE - 3) && (i <= SBUILD_ID_SIZE - 3) && 452 (d->d_name[i] == '\0'); 453 } 454 455 struct strlist *build_id_cache__list_all(bool validonly) 456 { 457 struct strlist *toplist, *linklist = NULL, *bidlist; 458 struct str_node *nd, *nd2; 459 char *topdir, *linkdir = NULL; 460 char sbuild_id[SBUILD_ID_SIZE]; 461 462 /* for filename__ functions */ 463 if (validonly) 464 symbol__init(NULL); 465 466 /* Open the top-level directory */ 467 if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0) 468 return NULL; 469 470 bidlist = strlist__new(NULL, NULL); 471 if (!bidlist) 472 goto out; 473 474 toplist = lsdir(topdir, lsdir_bid_head_filter); 475 if (!toplist) { 476 pr_debug("Error in lsdir(%s): %d\n", topdir, errno); 477 /* If there is no buildid cache, return an empty list */ 478 if (errno == ENOENT) 479 goto out; 480 goto err_out; 481 } 482 483 strlist__for_each_entry(nd, toplist) { 484 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0) 485 goto err_out; 486 /* Open the lower-level directory */ 487 linklist = lsdir(linkdir, lsdir_bid_tail_filter); 488 if (!linklist) { 489 pr_debug("Error in lsdir(%s): %d\n", linkdir, errno); 490 goto err_out; 491 } 492 strlist__for_each_entry(nd2, linklist) { 493 if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s", 494 nd->s, nd2->s) > SBUILD_ID_SIZE - 1) 495 goto err_out; 496 if (validonly && !build_id_cache__valid_id(sbuild_id)) 497 continue; 498 if (strlist__add(bidlist, sbuild_id) < 0) 499 goto err_out; 500 } 501 strlist__delete(linklist); 502 zfree(&linkdir); 503 } 504 505 out_free: 506 strlist__delete(toplist); 507 out: 508 free(topdir); 509 510 return bidlist; 511 512 err_out: 513 strlist__delete(linklist); 514 zfree(&linkdir); 515 strlist__delete(bidlist); 516 bidlist = NULL; 517 goto out_free; 518 } 519 520 static bool str_is_build_id(const char *maybe_sbuild_id, size_t len) 521 { 522 size_t i; 523 524 for (i = 0; i < len; i++) { 525 if (!isxdigit(maybe_sbuild_id[i])) 526 return false; 527 } 528 return true; 529 } 530 531 /* Return the valid complete build-id */ 532 char *build_id_cache__complement(const char *incomplete_sbuild_id) 533 { 534 struct strlist *bidlist; 535 struct str_node *nd, *cand = NULL; 536 char *sbuild_id = NULL; 537 size_t len = strlen(incomplete_sbuild_id); 538 539 if (len >= SBUILD_ID_SIZE || 540 !str_is_build_id(incomplete_sbuild_id, len)) 541 return NULL; 542 543 bidlist = build_id_cache__list_all(true); 544 if (!bidlist) 545 return NULL; 546 547 strlist__for_each_entry(nd, bidlist) { 548 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0) 549 continue; 550 if (cand) { /* Error: There are more than 2 candidates. */ 551 cand = NULL; 552 break; 553 } 554 cand = nd; 555 } 556 if (cand) 557 sbuild_id = strdup(cand->s); 558 strlist__delete(bidlist); 559 560 return sbuild_id; 561 } 562 563 char *build_id_cache__cachedir(const char *sbuild_id, const char *name, 564 struct nsinfo *nsi, bool is_kallsyms, 565 bool is_vdso) 566 { 567 char *realname = (char *)name, *filename; 568 bool slash = is_kallsyms || is_vdso; 569 570 if (!slash) { 571 realname = nsinfo__realpath(name, nsi); 572 if (!realname) 573 return NULL; 574 } 575 576 if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "", 577 is_vdso ? DSO__NAME_VDSO : realname, 578 sbuild_id ? "/" : "", sbuild_id ?: "") < 0) 579 filename = NULL; 580 581 if (!slash) 582 free(realname); 583 584 return filename; 585 } 586 587 int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi, 588 struct strlist **result) 589 { 590 char *dir_name; 591 int ret = 0; 592 593 dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false); 594 if (!dir_name) 595 return -ENOMEM; 596 597 *result = lsdir(dir_name, lsdir_no_dot_filter); 598 if (!*result) 599 ret = -errno; 600 free(dir_name); 601 602 return ret; 603 } 604 605 #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT) 606 static int build_id_cache__add_sdt_cache(const char *sbuild_id, 607 const char *realname, 608 struct nsinfo *nsi) 609 { 610 struct probe_cache *cache; 611 int ret; 612 struct nscookie nsc; 613 614 cache = probe_cache__new(sbuild_id, nsi); 615 if (!cache) 616 return -1; 617 618 nsinfo__mountns_enter(nsi, &nsc); 619 ret = probe_cache__scan_sdt(cache, realname); 620 nsinfo__mountns_exit(&nsc); 621 if (ret >= 0) { 622 pr_debug4("Found %d SDTs in %s\n", ret, realname); 623 if (probe_cache__commit(cache) < 0) 624 ret = -1; 625 } 626 probe_cache__delete(cache); 627 return ret; 628 } 629 #else 630 #define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0) 631 #endif 632 633 static char *build_id_cache__find_debug(const char *sbuild_id, 634 struct nsinfo *nsi) 635 { 636 char *realname = NULL; 637 char *debugfile; 638 struct nscookie nsc; 639 size_t len = 0; 640 641 debugfile = calloc(1, PATH_MAX); 642 if (!debugfile) 643 goto out; 644 645 len = __symbol__join_symfs(debugfile, PATH_MAX, 646 "/usr/lib/debug/.build-id/"); 647 snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id, 648 sbuild_id + 2); 649 650 nsinfo__mountns_enter(nsi, &nsc); 651 realname = realpath(debugfile, NULL); 652 if (realname && access(realname, R_OK)) 653 zfree(&realname); 654 nsinfo__mountns_exit(&nsc); 655 656 #ifdef HAVE_DEBUGINFOD_SUPPORT 657 if (realname == NULL) { 658 debuginfod_client* c = debuginfod_begin(); 659 if (c != NULL) { 660 int fd = debuginfod_find_debuginfo(c, 661 (const unsigned char*)sbuild_id, 0, 662 &realname); 663 if (fd >= 0) 664 close(fd); /* retaining reference by realname */ 665 debuginfod_end(c); 666 } 667 } 668 #endif 669 670 out: 671 free(debugfile); 672 return realname; 673 } 674 675 int 676 build_id_cache__add(const char *sbuild_id, const char *name, const char *realname, 677 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso) 678 { 679 const size_t size = PATH_MAX; 680 char *filename = NULL, *dir_name = NULL, *linkname = zalloc(size), *tmp; 681 char *debugfile = NULL; 682 int err = -1; 683 684 dir_name = build_id_cache__cachedir(sbuild_id, name, nsi, is_kallsyms, 685 is_vdso); 686 if (!dir_name) 687 goto out_free; 688 689 /* Remove old style build-id cache */ 690 if (is_regular_file(dir_name)) 691 if (unlink(dir_name)) 692 goto out_free; 693 694 if (mkdir_p(dir_name, 0755)) 695 goto out_free; 696 697 /* Save the allocated buildid dirname */ 698 if (asprintf(&filename, "%s/%s", dir_name, 699 build_id_cache__basename(is_kallsyms, is_vdso, 700 false)) < 0) { 701 filename = NULL; 702 goto out_free; 703 } 704 705 if (access(filename, F_OK)) { 706 if (is_kallsyms) { 707 if (copyfile("/proc/kallsyms", filename)) 708 goto out_free; 709 } else if (nsi && nsinfo__need_setns(nsi)) { 710 if (copyfile_ns(name, filename, nsi)) 711 goto out_free; 712 } else if (link(realname, filename) && errno != EEXIST && 713 copyfile(name, filename)) 714 goto out_free; 715 } 716 717 /* Some binaries are stripped, but have .debug files with their symbol 718 * table. Check to see if we can locate one of those, since the elf 719 * file itself may not be very useful to users of our tools without a 720 * symtab. 721 */ 722 if (!is_kallsyms && !is_vdso && 723 strncmp(".ko", name + strlen(name) - 3, 3)) { 724 debugfile = build_id_cache__find_debug(sbuild_id, nsi); 725 if (debugfile) { 726 zfree(&filename); 727 if (asprintf(&filename, "%s/%s", dir_name, 728 build_id_cache__basename(false, false, true)) < 0) { 729 filename = NULL; 730 goto out_free; 731 } 732 if (access(filename, F_OK)) { 733 if (nsi && nsinfo__need_setns(nsi)) { 734 if (copyfile_ns(debugfile, filename, 735 nsi)) 736 goto out_free; 737 } else if (link(debugfile, filename) && 738 errno != EEXIST && 739 copyfile(debugfile, filename)) 740 goto out_free; 741 } 742 } 743 } 744 745 if (!build_id_cache__linkname(sbuild_id, linkname, size)) 746 goto out_free; 747 tmp = strrchr(linkname, '/'); 748 *tmp = '\0'; 749 750 if (access(linkname, X_OK) && mkdir_p(linkname, 0755)) 751 goto out_free; 752 753 *tmp = '/'; 754 tmp = dir_name + strlen(buildid_dir) - 5; 755 memcpy(tmp, "../..", 5); 756 757 if (symlink(tmp, linkname) == 0) { 758 err = 0; 759 } else if (errno == EEXIST) { 760 char path[PATH_MAX]; 761 ssize_t len; 762 763 len = readlink(linkname, path, sizeof(path) - 1); 764 if (len <= 0) { 765 pr_err("Can't read link: %s\n", linkname); 766 goto out_free; 767 } 768 path[len] = '\0'; 769 770 if (strcmp(tmp, path)) { 771 pr_debug("build <%s> already linked to %s\n", 772 sbuild_id, linkname); 773 } 774 err = 0; 775 } 776 777 /* Update SDT cache : error is just warned */ 778 if (realname && 779 build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0) 780 pr_debug4("Failed to update/scan SDT cache for %s\n", realname); 781 782 out_free: 783 free(filename); 784 free(debugfile); 785 free(dir_name); 786 free(linkname); 787 return err; 788 } 789 790 int build_id_cache__add_s(const char *sbuild_id, const char *name, 791 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso) 792 { 793 char *realname = NULL; 794 int err = -1; 795 796 if (!is_kallsyms) { 797 if (!is_vdso) 798 realname = nsinfo__realpath(name, nsi); 799 else 800 realname = realpath(name, NULL); 801 if (!realname) 802 goto out_free; 803 } 804 805 err = build_id_cache__add(sbuild_id, name, realname, nsi, is_kallsyms, is_vdso); 806 807 out_free: 808 if (!is_kallsyms) 809 free(realname); 810 return err; 811 } 812 813 static int build_id_cache__add_b(const struct build_id *bid, 814 const char *name, struct nsinfo *nsi, 815 bool is_kallsyms, bool is_vdso) 816 { 817 char sbuild_id[SBUILD_ID_SIZE]; 818 819 build_id__sprintf(bid, sbuild_id); 820 821 return build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms, 822 is_vdso); 823 } 824 825 bool build_id_cache__cached(const char *sbuild_id) 826 { 827 bool ret = false; 828 char *filename = build_id_cache__linkname(sbuild_id, NULL, 0); 829 830 if (filename && !access(filename, F_OK)) 831 ret = true; 832 free(filename); 833 834 return ret; 835 } 836 837 int build_id_cache__remove_s(const char *sbuild_id) 838 { 839 const size_t size = PATH_MAX; 840 char *filename = zalloc(size), 841 *linkname = zalloc(size), *tmp; 842 int err = -1; 843 844 if (filename == NULL || linkname == NULL) 845 goto out_free; 846 847 if (!build_id_cache__linkname(sbuild_id, linkname, size)) 848 goto out_free; 849 850 if (access(linkname, F_OK)) 851 goto out_free; 852 853 if (readlink(linkname, filename, size - 1) < 0) 854 goto out_free; 855 856 if (unlink(linkname)) 857 goto out_free; 858 859 /* 860 * Since the link is relative, we must make it absolute: 861 */ 862 tmp = strrchr(linkname, '/') + 1; 863 snprintf(tmp, size - (tmp - linkname), "%s", filename); 864 865 if (rm_rf(linkname)) 866 goto out_free; 867 868 err = 0; 869 out_free: 870 free(filename); 871 free(linkname); 872 return err; 873 } 874 875 static int filename__read_build_id_ns(const char *filename, 876 struct build_id *bid, 877 struct nsinfo *nsi) 878 { 879 struct nscookie nsc; 880 int ret; 881 882 nsinfo__mountns_enter(nsi, &nsc); 883 ret = filename__read_build_id(filename, bid); 884 nsinfo__mountns_exit(&nsc); 885 886 return ret; 887 } 888 889 static bool dso__build_id_mismatch(struct dso *dso, const char *name) 890 { 891 struct build_id bid; 892 893 if (filename__read_build_id_ns(name, &bid, dso->nsinfo) < 0) 894 return false; 895 896 return !dso__build_id_equal(dso, &bid); 897 } 898 899 static int dso__cache_build_id(struct dso *dso, struct machine *machine, 900 void *priv __maybe_unused) 901 { 902 bool is_kallsyms = dso__is_kallsyms(dso); 903 bool is_vdso = dso__is_vdso(dso); 904 const char *name = dso->long_name; 905 906 if (!dso->has_build_id) 907 return 0; 908 909 if (dso__is_kcore(dso)) { 910 is_kallsyms = true; 911 name = machine->mmap_name; 912 } 913 914 if (!is_kallsyms && dso__build_id_mismatch(dso, name)) 915 return 0; 916 917 return build_id_cache__add_b(&dso->bid, name, dso->nsinfo, 918 is_kallsyms, is_vdso); 919 } 920 921 static int 922 machines__for_each_dso(struct machines *machines, machine__dso_t fn, void *priv) 923 { 924 int ret = machine__for_each_dso(&machines->host, fn, priv); 925 struct rb_node *nd; 926 927 for (nd = rb_first_cached(&machines->guests); nd; 928 nd = rb_next(nd)) { 929 struct machine *pos = rb_entry(nd, struct machine, rb_node); 930 931 ret |= machine__for_each_dso(pos, fn, priv); 932 } 933 return ret ? -1 : 0; 934 } 935 936 int __perf_session__cache_build_ids(struct perf_session *session, 937 machine__dso_t fn, void *priv) 938 { 939 if (no_buildid_cache) 940 return 0; 941 942 if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST) 943 return -1; 944 945 return machines__for_each_dso(&session->machines, fn, priv) ? -1 : 0; 946 } 947 948 int perf_session__cache_build_ids(struct perf_session *session) 949 { 950 return __perf_session__cache_build_ids(session, dso__cache_build_id, NULL); 951 } 952 953 static bool machine__read_build_ids(struct machine *machine, bool with_hits) 954 { 955 return __dsos__read_build_ids(&machine->dsos.head, with_hits); 956 } 957 958 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits) 959 { 960 struct rb_node *nd; 961 bool ret = machine__read_build_ids(&session->machines.host, with_hits); 962 963 for (nd = rb_first_cached(&session->machines.guests); nd; 964 nd = rb_next(nd)) { 965 struct machine *pos = rb_entry(nd, struct machine, rb_node); 966 ret |= machine__read_build_ids(pos, with_hits); 967 } 968 969 return ret; 970 } 971 972 void build_id__init(struct build_id *bid, const u8 *data, size_t size) 973 { 974 WARN_ON(size > BUILD_ID_SIZE); 975 memcpy(bid->data, data, size); 976 bid->size = size; 977 } 978 979 bool build_id__is_defined(const struct build_id *bid) 980 { 981 return bid && bid->size ? !!memchr_inv(bid->data, 0, bid->size) : false; 982 } 983