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 static int write_buildid(const char *name, size_t name_len, struct build_id *bid, 304 pid_t pid, u16 misc, struct feat_fd *fd) 305 { 306 int err; 307 struct perf_record_header_build_id b; 308 size_t len; 309 310 len = name_len + 1; 311 len = PERF_ALIGN(len, NAME_ALIGN); 312 313 memset(&b, 0, sizeof(b)); 314 memcpy(&b.data, bid->data, bid->size); 315 b.size = (u8) bid->size; 316 misc |= PERF_RECORD_MISC_BUILD_ID_SIZE; 317 b.pid = pid; 318 b.header.misc = misc; 319 b.header.size = sizeof(b) + len; 320 321 err = do_write(fd, &b, sizeof(b)); 322 if (err < 0) 323 return err; 324 325 return write_padded(fd, name, name_len + 1, len); 326 } 327 328 static int machine__write_buildid_table(struct machine *machine, 329 struct feat_fd *fd) 330 { 331 int err = 0; 332 struct dso *pos; 333 u16 kmisc = PERF_RECORD_MISC_KERNEL, 334 umisc = PERF_RECORD_MISC_USER; 335 336 if (!machine__is_host(machine)) { 337 kmisc = PERF_RECORD_MISC_GUEST_KERNEL; 338 umisc = PERF_RECORD_MISC_GUEST_USER; 339 } 340 341 dsos__for_each_with_build_id(pos, &machine->dsos.head) { 342 const char *name; 343 size_t name_len; 344 bool in_kernel = false; 345 346 if (!pos->hit && !dso__is_vdso(pos)) 347 continue; 348 349 if (dso__is_vdso(pos)) { 350 name = pos->short_name; 351 name_len = pos->short_name_len; 352 } else if (dso__is_kcore(pos)) { 353 name = machine->mmap_name; 354 name_len = strlen(name); 355 } else { 356 name = pos->long_name; 357 name_len = pos->long_name_len; 358 } 359 360 in_kernel = pos->kernel || 361 is_kernel_module(name, 362 PERF_RECORD_MISC_CPUMODE_UNKNOWN); 363 err = write_buildid(name, name_len, &pos->bid, machine->pid, 364 in_kernel ? kmisc : umisc, fd); 365 if (err) 366 break; 367 } 368 369 return err; 370 } 371 372 int perf_session__write_buildid_table(struct perf_session *session, 373 struct feat_fd *fd) 374 { 375 struct rb_node *nd; 376 int err = machine__write_buildid_table(&session->machines.host, fd); 377 378 if (err) 379 return err; 380 381 for (nd = rb_first_cached(&session->machines.guests); nd; 382 nd = rb_next(nd)) { 383 struct machine *pos = rb_entry(nd, struct machine, rb_node); 384 err = machine__write_buildid_table(pos, fd); 385 if (err) 386 break; 387 } 388 return err; 389 } 390 391 static int __dsos__hit_all(struct list_head *head) 392 { 393 struct dso *pos; 394 395 list_for_each_entry(pos, head, node) 396 pos->hit = true; 397 398 return 0; 399 } 400 401 static int machine__hit_all_dsos(struct machine *machine) 402 { 403 return __dsos__hit_all(&machine->dsos.head); 404 } 405 406 int dsos__hit_all(struct perf_session *session) 407 { 408 struct rb_node *nd; 409 int err; 410 411 err = machine__hit_all_dsos(&session->machines.host); 412 if (err) 413 return err; 414 415 for (nd = rb_first_cached(&session->machines.guests); nd; 416 nd = rb_next(nd)) { 417 struct machine *pos = rb_entry(nd, struct machine, rb_node); 418 419 err = machine__hit_all_dsos(pos); 420 if (err) 421 return err; 422 } 423 424 return 0; 425 } 426 427 void disable_buildid_cache(void) 428 { 429 no_buildid_cache = true; 430 } 431 432 static bool lsdir_bid_head_filter(const char *name __maybe_unused, 433 struct dirent *d) 434 { 435 return (strlen(d->d_name) == 2) && 436 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]); 437 } 438 439 static bool lsdir_bid_tail_filter(const char *name __maybe_unused, 440 struct dirent *d) 441 { 442 int i = 0; 443 while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3) 444 i++; 445 return (i >= SBUILD_ID_MIN_SIZE - 3) && (i <= SBUILD_ID_SIZE - 3) && 446 (d->d_name[i] == '\0'); 447 } 448 449 struct strlist *build_id_cache__list_all(bool validonly) 450 { 451 struct strlist *toplist, *linklist = NULL, *bidlist; 452 struct str_node *nd, *nd2; 453 char *topdir, *linkdir = NULL; 454 char sbuild_id[SBUILD_ID_SIZE]; 455 456 /* for filename__ functions */ 457 if (validonly) 458 symbol__init(NULL); 459 460 /* Open the top-level directory */ 461 if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0) 462 return NULL; 463 464 bidlist = strlist__new(NULL, NULL); 465 if (!bidlist) 466 goto out; 467 468 toplist = lsdir(topdir, lsdir_bid_head_filter); 469 if (!toplist) { 470 pr_debug("Error in lsdir(%s): %d\n", topdir, errno); 471 /* If there is no buildid cache, return an empty list */ 472 if (errno == ENOENT) 473 goto out; 474 goto err_out; 475 } 476 477 strlist__for_each_entry(nd, toplist) { 478 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0) 479 goto err_out; 480 /* Open the lower-level directory */ 481 linklist = lsdir(linkdir, lsdir_bid_tail_filter); 482 if (!linklist) { 483 pr_debug("Error in lsdir(%s): %d\n", linkdir, errno); 484 goto err_out; 485 } 486 strlist__for_each_entry(nd2, linklist) { 487 if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s", 488 nd->s, nd2->s) > SBUILD_ID_SIZE - 1) 489 goto err_out; 490 if (validonly && !build_id_cache__valid_id(sbuild_id)) 491 continue; 492 if (strlist__add(bidlist, sbuild_id) < 0) 493 goto err_out; 494 } 495 strlist__delete(linklist); 496 zfree(&linkdir); 497 } 498 499 out_free: 500 strlist__delete(toplist); 501 out: 502 free(topdir); 503 504 return bidlist; 505 506 err_out: 507 strlist__delete(linklist); 508 zfree(&linkdir); 509 strlist__delete(bidlist); 510 bidlist = NULL; 511 goto out_free; 512 } 513 514 static bool str_is_build_id(const char *maybe_sbuild_id, size_t len) 515 { 516 size_t i; 517 518 for (i = 0; i < len; i++) { 519 if (!isxdigit(maybe_sbuild_id[i])) 520 return false; 521 } 522 return true; 523 } 524 525 /* Return the valid complete build-id */ 526 char *build_id_cache__complement(const char *incomplete_sbuild_id) 527 { 528 struct strlist *bidlist; 529 struct str_node *nd, *cand = NULL; 530 char *sbuild_id = NULL; 531 size_t len = strlen(incomplete_sbuild_id); 532 533 if (len >= SBUILD_ID_SIZE || 534 !str_is_build_id(incomplete_sbuild_id, len)) 535 return NULL; 536 537 bidlist = build_id_cache__list_all(true); 538 if (!bidlist) 539 return NULL; 540 541 strlist__for_each_entry(nd, bidlist) { 542 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0) 543 continue; 544 if (cand) { /* Error: There are more than 2 candidates. */ 545 cand = NULL; 546 break; 547 } 548 cand = nd; 549 } 550 if (cand) 551 sbuild_id = strdup(cand->s); 552 strlist__delete(bidlist); 553 554 return sbuild_id; 555 } 556 557 char *build_id_cache__cachedir(const char *sbuild_id, const char *name, 558 struct nsinfo *nsi, bool is_kallsyms, 559 bool is_vdso) 560 { 561 char *realname = (char *)name, *filename; 562 bool slash = is_kallsyms || is_vdso; 563 564 if (!slash) 565 realname = nsinfo__realpath(name, nsi); 566 567 if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "", 568 is_vdso ? DSO__NAME_VDSO : (realname ? realname : name), 569 sbuild_id ? "/" : "", sbuild_id ?: "") < 0) 570 filename = NULL; 571 572 if (!slash) 573 free(realname); 574 575 return filename; 576 } 577 578 int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi, 579 struct strlist **result) 580 { 581 char *dir_name; 582 int ret = 0; 583 584 dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false); 585 if (!dir_name) 586 return -ENOMEM; 587 588 *result = lsdir(dir_name, lsdir_no_dot_filter); 589 if (!*result) 590 ret = -errno; 591 free(dir_name); 592 593 return ret; 594 } 595 596 #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT) 597 static int build_id_cache__add_sdt_cache(const char *sbuild_id, 598 const char *realname, 599 struct nsinfo *nsi) 600 { 601 struct probe_cache *cache; 602 int ret; 603 struct nscookie nsc; 604 605 cache = probe_cache__new(sbuild_id, nsi); 606 if (!cache) 607 return -1; 608 609 nsinfo__mountns_enter(nsi, &nsc); 610 ret = probe_cache__scan_sdt(cache, realname); 611 nsinfo__mountns_exit(&nsc); 612 if (ret >= 0) { 613 pr_debug4("Found %d SDTs in %s\n", ret, realname); 614 if (probe_cache__commit(cache) < 0) 615 ret = -1; 616 } 617 probe_cache__delete(cache); 618 return ret; 619 } 620 #else 621 #define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0) 622 #endif 623 624 static char *build_id_cache__find_debug(const char *sbuild_id, 625 struct nsinfo *nsi, 626 const char *root_dir) 627 { 628 const char *dirname = "/usr/lib/debug/.build-id/"; 629 char *realname = NULL; 630 char dirbuf[PATH_MAX]; 631 char *debugfile; 632 struct nscookie nsc; 633 size_t len = 0; 634 635 debugfile = calloc(1, PATH_MAX); 636 if (!debugfile) 637 goto out; 638 639 if (root_dir) { 640 path__join(dirbuf, PATH_MAX, root_dir, dirname); 641 dirname = dirbuf; 642 } 643 644 len = __symbol__join_symfs(debugfile, PATH_MAX, dirname); 645 snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id, 646 sbuild_id + 2); 647 648 nsinfo__mountns_enter(nsi, &nsc); 649 realname = realpath(debugfile, NULL); 650 if (realname && access(realname, R_OK)) 651 zfree(&realname); 652 nsinfo__mountns_exit(&nsc); 653 654 #ifdef HAVE_DEBUGINFOD_SUPPORT 655 if (realname == NULL) { 656 debuginfod_client* c; 657 658 pr_debug("Downloading debug info with build id %s\n", sbuild_id); 659 660 c = debuginfod_begin(); 661 if (c != NULL) { 662 int fd = debuginfod_find_debuginfo(c, 663 (const unsigned char*)sbuild_id, 0, 664 &realname); 665 if (fd >= 0) 666 close(fd); /* retaining reference by realname */ 667 debuginfod_end(c); 668 } 669 } 670 #endif 671 672 out: 673 free(debugfile); 674 return realname; 675 } 676 677 int 678 build_id_cache__add(const char *sbuild_id, const char *name, const char *realname, 679 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso, 680 const char *proper_name, const char *root_dir) 681 { 682 const size_t size = PATH_MAX; 683 char *filename = NULL, *dir_name = NULL, *linkname = zalloc(size), *tmp; 684 char *debugfile = NULL; 685 int err = -1; 686 687 if (!proper_name) 688 proper_name = name; 689 690 dir_name = build_id_cache__cachedir(sbuild_id, proper_name, nsi, is_kallsyms, 691 is_vdso); 692 if (!dir_name) 693 goto out_free; 694 695 /* Remove old style build-id cache */ 696 if (is_regular_file(dir_name)) 697 if (unlink(dir_name)) 698 goto out_free; 699 700 if (mkdir_p(dir_name, 0755)) 701 goto out_free; 702 703 /* Save the allocated buildid dirname */ 704 if (asprintf(&filename, "%s/%s", dir_name, 705 build_id_cache__basename(is_kallsyms, is_vdso, 706 false)) < 0) { 707 filename = NULL; 708 goto out_free; 709 } 710 711 if (access(filename, F_OK)) { 712 if (is_kallsyms) { 713 if (copyfile("/proc/kallsyms", filename)) 714 goto out_free; 715 } else if (nsi && nsinfo__need_setns(nsi)) { 716 if (copyfile_ns(name, filename, nsi)) 717 goto out_free; 718 } else if (link(realname, filename) && errno != EEXIST) { 719 struct stat f_stat; 720 721 if (!(stat(name, &f_stat) < 0) && 722 copyfile_mode(name, filename, f_stat.st_mode)) 723 goto out_free; 724 } 725 } 726 727 /* Some binaries are stripped, but have .debug files with their symbol 728 * table. Check to see if we can locate one of those, since the elf 729 * file itself may not be very useful to users of our tools without a 730 * symtab. 731 */ 732 if (!is_kallsyms && !is_vdso && 733 strncmp(".ko", name + strlen(name) - 3, 3)) { 734 debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir); 735 if (debugfile) { 736 zfree(&filename); 737 if (asprintf(&filename, "%s/%s", dir_name, 738 build_id_cache__basename(false, false, true)) < 0) { 739 filename = NULL; 740 goto out_free; 741 } 742 if (access(filename, F_OK)) { 743 if (nsi && nsinfo__need_setns(nsi)) { 744 if (copyfile_ns(debugfile, filename, 745 nsi)) 746 goto out_free; 747 } else if (link(debugfile, filename) && 748 errno != EEXIST && 749 copyfile(debugfile, filename)) 750 goto out_free; 751 } 752 } 753 } 754 755 if (!build_id_cache__linkname(sbuild_id, linkname, size)) 756 goto out_free; 757 tmp = strrchr(linkname, '/'); 758 *tmp = '\0'; 759 760 if (access(linkname, X_OK) && mkdir_p(linkname, 0755)) 761 goto out_free; 762 763 *tmp = '/'; 764 tmp = dir_name + strlen(buildid_dir) - 5; 765 memcpy(tmp, "../..", 5); 766 767 if (symlink(tmp, linkname) == 0) { 768 err = 0; 769 } else if (errno == EEXIST) { 770 char path[PATH_MAX]; 771 ssize_t len; 772 773 len = readlink(linkname, path, sizeof(path) - 1); 774 if (len <= 0) { 775 pr_err("Can't read link: %s\n", linkname); 776 goto out_free; 777 } 778 path[len] = '\0'; 779 780 if (strcmp(tmp, path)) { 781 pr_debug("build <%s> already linked to %s\n", 782 sbuild_id, linkname); 783 } 784 err = 0; 785 } 786 787 /* Update SDT cache : error is just warned */ 788 if (realname && 789 build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0) 790 pr_debug4("Failed to update/scan SDT cache for %s\n", realname); 791 792 out_free: 793 free(filename); 794 free(debugfile); 795 free(dir_name); 796 free(linkname); 797 return err; 798 } 799 800 int __build_id_cache__add_s(const char *sbuild_id, const char *name, 801 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso, 802 const char *proper_name, const char *root_dir) 803 { 804 char *realname = NULL; 805 int err = -1; 806 807 if (!is_kallsyms) { 808 if (!is_vdso) 809 realname = nsinfo__realpath(name, nsi); 810 else 811 realname = realpath(name, NULL); 812 if (!realname) 813 goto out_free; 814 } 815 816 err = build_id_cache__add(sbuild_id, name, realname, nsi, 817 is_kallsyms, is_vdso, proper_name, root_dir); 818 out_free: 819 if (!is_kallsyms) 820 free(realname); 821 return err; 822 } 823 824 static int build_id_cache__add_b(const struct build_id *bid, 825 const char *name, struct nsinfo *nsi, 826 bool is_kallsyms, bool is_vdso, 827 const char *proper_name, 828 const char *root_dir) 829 { 830 char sbuild_id[SBUILD_ID_SIZE]; 831 832 build_id__sprintf(bid, sbuild_id); 833 834 return __build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms, 835 is_vdso, proper_name, root_dir); 836 } 837 838 bool build_id_cache__cached(const char *sbuild_id) 839 { 840 bool ret = false; 841 char *filename = build_id_cache__linkname(sbuild_id, NULL, 0); 842 843 if (filename && !access(filename, F_OK)) 844 ret = true; 845 free(filename); 846 847 return ret; 848 } 849 850 int build_id_cache__remove_s(const char *sbuild_id) 851 { 852 const size_t size = PATH_MAX; 853 char *filename = zalloc(size), 854 *linkname = zalloc(size), *tmp; 855 int err = -1; 856 857 if (filename == NULL || linkname == NULL) 858 goto out_free; 859 860 if (!build_id_cache__linkname(sbuild_id, linkname, size)) 861 goto out_free; 862 863 if (access(linkname, F_OK)) 864 goto out_free; 865 866 if (readlink(linkname, filename, size - 1) < 0) 867 goto out_free; 868 869 if (unlink(linkname)) 870 goto out_free; 871 872 /* 873 * Since the link is relative, we must make it absolute: 874 */ 875 tmp = strrchr(linkname, '/') + 1; 876 snprintf(tmp, size - (tmp - linkname), "%s", filename); 877 878 if (rm_rf(linkname)) 879 goto out_free; 880 881 err = 0; 882 out_free: 883 free(filename); 884 free(linkname); 885 return err; 886 } 887 888 static int filename__read_build_id_ns(const char *filename, 889 struct build_id *bid, 890 struct nsinfo *nsi) 891 { 892 struct nscookie nsc; 893 int ret; 894 895 nsinfo__mountns_enter(nsi, &nsc); 896 ret = filename__read_build_id(filename, bid); 897 nsinfo__mountns_exit(&nsc); 898 899 return ret; 900 } 901 902 static bool dso__build_id_mismatch(struct dso *dso, const char *name) 903 { 904 struct build_id bid; 905 bool ret = false; 906 907 mutex_lock(&dso->lock); 908 if (filename__read_build_id_ns(name, &bid, dso->nsinfo) >= 0) 909 ret = !dso__build_id_equal(dso, &bid); 910 911 mutex_unlock(&dso->lock); 912 913 return ret; 914 } 915 916 static int dso__cache_build_id(struct dso *dso, struct machine *machine, 917 void *priv __maybe_unused) 918 { 919 bool is_kallsyms = dso__is_kallsyms(dso); 920 bool is_vdso = dso__is_vdso(dso); 921 const char *name = dso->long_name; 922 const char *proper_name = NULL; 923 const char *root_dir = NULL; 924 char *allocated_name = NULL; 925 int ret = 0; 926 927 if (!dso->has_build_id) 928 return 0; 929 930 if (dso__is_kcore(dso)) { 931 is_kallsyms = true; 932 name = machine->mmap_name; 933 } 934 935 if (!machine__is_host(machine)) { 936 if (*machine->root_dir) { 937 root_dir = machine->root_dir; 938 ret = asprintf(&allocated_name, "%s/%s", root_dir, name); 939 if (ret < 0) 940 return ret; 941 proper_name = name; 942 name = allocated_name; 943 } else if (is_kallsyms) { 944 /* Cannot get guest kallsyms */ 945 return 0; 946 } 947 } 948 949 if (!is_kallsyms && dso__build_id_mismatch(dso, name)) 950 goto out_free; 951 952 mutex_lock(&dso->lock); 953 ret = build_id_cache__add_b(&dso->bid, name, dso->nsinfo, 954 is_kallsyms, is_vdso, proper_name, root_dir); 955 mutex_unlock(&dso->lock); 956 out_free: 957 free(allocated_name); 958 return ret; 959 } 960 961 static int 962 machines__for_each_dso(struct machines *machines, machine__dso_t fn, void *priv) 963 { 964 int ret = machine__for_each_dso(&machines->host, fn, priv); 965 struct rb_node *nd; 966 967 for (nd = rb_first_cached(&machines->guests); nd; 968 nd = rb_next(nd)) { 969 struct machine *pos = rb_entry(nd, struct machine, rb_node); 970 971 ret |= machine__for_each_dso(pos, fn, priv); 972 } 973 return ret ? -1 : 0; 974 } 975 976 int __perf_session__cache_build_ids(struct perf_session *session, 977 machine__dso_t fn, void *priv) 978 { 979 if (no_buildid_cache) 980 return 0; 981 982 if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST) 983 return -1; 984 985 return machines__for_each_dso(&session->machines, fn, priv) ? -1 : 0; 986 } 987 988 int perf_session__cache_build_ids(struct perf_session *session) 989 { 990 return __perf_session__cache_build_ids(session, dso__cache_build_id, NULL); 991 } 992 993 static bool machine__read_build_ids(struct machine *machine, bool with_hits) 994 { 995 return __dsos__read_build_ids(&machine->dsos.head, with_hits); 996 } 997 998 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits) 999 { 1000 struct rb_node *nd; 1001 bool ret = machine__read_build_ids(&session->machines.host, with_hits); 1002 1003 for (nd = rb_first_cached(&session->machines.guests); nd; 1004 nd = rb_next(nd)) { 1005 struct machine *pos = rb_entry(nd, struct machine, rb_node); 1006 ret |= machine__read_build_ids(pos, with_hits); 1007 } 1008 1009 return ret; 1010 } 1011 1012 void build_id__init(struct build_id *bid, const u8 *data, size_t size) 1013 { 1014 WARN_ON(size > BUILD_ID_SIZE); 1015 memcpy(bid->data, data, size); 1016 bid->size = size; 1017 } 1018 1019 bool build_id__is_defined(const struct build_id *bid) 1020 { 1021 return bid && bid->size ? !!memchr_inv(bid->data, 0, bid->size) : false; 1022 } 1023