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 addr_location__init(&al); 62 if (thread__find_map(thread, sample->cpumode, sample->ip, &al)) 63 map__dso(al.map)->hit = 1; 64 65 addr_location__exit(&al); 66 thread__put(thread); 67 return 0; 68 } 69 70 static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused, 71 union perf_event *event, 72 struct perf_sample *sample 73 __maybe_unused, 74 struct machine *machine) 75 { 76 struct thread *thread = machine__findnew_thread(machine, 77 event->fork.pid, 78 event->fork.tid); 79 80 dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid, 81 event->fork.ppid, event->fork.ptid); 82 83 if (thread) { 84 machine__remove_thread(machine, thread); 85 thread__put(thread); 86 } 87 88 return 0; 89 } 90 91 struct perf_tool build_id__mark_dso_hit_ops = { 92 .sample = build_id__mark_dso_hit, 93 .mmap = perf_event__process_mmap, 94 .mmap2 = perf_event__process_mmap2, 95 .fork = perf_event__process_fork, 96 .exit = perf_event__exit_del_thread, 97 .attr = perf_event__process_attr, 98 .build_id = perf_event__process_build_id, 99 .ordered_events = true, 100 }; 101 102 int build_id__sprintf(const struct build_id *build_id, char *bf) 103 { 104 char *bid = bf; 105 const u8 *raw = build_id->data; 106 size_t i; 107 108 bf[0] = 0x0; 109 110 for (i = 0; i < build_id->size; ++i) { 111 sprintf(bid, "%02x", *raw); 112 ++raw; 113 bid += 2; 114 } 115 116 return (bid - bf) + 1; 117 } 118 119 int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id) 120 { 121 char notes[PATH_MAX]; 122 struct build_id bid; 123 int ret; 124 125 if (!root_dir) 126 root_dir = ""; 127 128 scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir); 129 130 ret = sysfs__read_build_id(notes, &bid); 131 if (ret < 0) 132 return ret; 133 134 return build_id__sprintf(&bid, sbuild_id); 135 } 136 137 int filename__sprintf_build_id(const char *pathname, char *sbuild_id) 138 { 139 struct build_id bid; 140 int ret; 141 142 ret = filename__read_build_id(pathname, &bid); 143 if (ret < 0) 144 return ret; 145 146 return build_id__sprintf(&bid, sbuild_id); 147 } 148 149 /* asnprintf consolidates asprintf and snprintf */ 150 static int asnprintf(char **strp, size_t size, const char *fmt, ...) 151 { 152 va_list ap; 153 int ret; 154 155 if (!strp) 156 return -EINVAL; 157 158 va_start(ap, fmt); 159 if (*strp) 160 ret = vsnprintf(*strp, size, fmt, ap); 161 else 162 ret = vasprintf(strp, fmt, ap); 163 va_end(ap); 164 165 return ret; 166 } 167 168 char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf, 169 size_t size) 170 { 171 bool retry_old = true; 172 173 snprintf(bf, size, "%s/%s/%s/kallsyms", 174 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); 175 retry: 176 if (!access(bf, F_OK)) 177 return bf; 178 if (retry_old) { 179 /* Try old style kallsyms cache */ 180 snprintf(bf, size, "%s/%s/%s", 181 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); 182 retry_old = false; 183 goto retry; 184 } 185 186 return NULL; 187 } 188 189 char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size) 190 { 191 char *tmp = bf; 192 int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir, 193 sbuild_id, sbuild_id + 2); 194 if (ret < 0 || (tmp && size < (unsigned int)ret)) 195 return NULL; 196 return bf; 197 } 198 199 /* The caller is responsible to free the returned buffer. */ 200 char *build_id_cache__origname(const char *sbuild_id) 201 { 202 char *linkname; 203 char buf[PATH_MAX]; 204 char *ret = NULL, *p; 205 size_t offs = 5; /* == strlen("../..") */ 206 ssize_t len; 207 208 linkname = build_id_cache__linkname(sbuild_id, NULL, 0); 209 if (!linkname) 210 return NULL; 211 212 len = readlink(linkname, buf, sizeof(buf) - 1); 213 if (len <= 0) 214 goto out; 215 buf[len] = '\0'; 216 217 /* The link should be "../..<origpath>/<sbuild_id>" */ 218 p = strrchr(buf, '/'); /* Cut off the "/<sbuild_id>" */ 219 if (p && (p > buf + offs)) { 220 *p = '\0'; 221 if (buf[offs + 1] == '[') 222 offs++; /* 223 * This is a DSO name, like [kernel.kallsyms]. 224 * Skip the first '/', since this is not the 225 * cache of a regular file. 226 */ 227 ret = strdup(buf + offs); /* Skip "../..[/]" */ 228 } 229 out: 230 free(linkname); 231 return ret; 232 } 233 234 /* Check if the given build_id cache is valid on current running system */ 235 static bool build_id_cache__valid_id(char *sbuild_id) 236 { 237 char real_sbuild_id[SBUILD_ID_SIZE] = ""; 238 char *pathname; 239 int ret = 0; 240 bool result = false; 241 242 pathname = build_id_cache__origname(sbuild_id); 243 if (!pathname) 244 return false; 245 246 if (!strcmp(pathname, DSO__NAME_KALLSYMS)) 247 ret = sysfs__sprintf_build_id("/", real_sbuild_id); 248 else if (pathname[0] == '/') 249 ret = filename__sprintf_build_id(pathname, real_sbuild_id); 250 else 251 ret = -EINVAL; /* Should we support other special DSO cache? */ 252 if (ret >= 0) 253 result = (strcmp(sbuild_id, real_sbuild_id) == 0); 254 free(pathname); 255 256 return result; 257 } 258 259 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso, 260 bool is_debug) 261 { 262 return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ? 263 "debug" : "elf")); 264 } 265 266 char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size, 267 bool is_debug, bool is_kallsyms) 268 { 269 bool is_vdso = dso__is_vdso((struct dso *)dso); 270 char sbuild_id[SBUILD_ID_SIZE]; 271 char *linkname; 272 bool alloc = (bf == NULL); 273 int ret; 274 275 if (!dso->has_build_id) 276 return NULL; 277 278 build_id__sprintf(&dso->bid, sbuild_id); 279 linkname = build_id_cache__linkname(sbuild_id, NULL, 0); 280 if (!linkname) 281 return NULL; 282 283 /* Check if old style build_id cache */ 284 if (is_regular_file(linkname)) 285 ret = asnprintf(&bf, size, "%s", linkname); 286 else 287 ret = asnprintf(&bf, size, "%s/%s", linkname, 288 build_id_cache__basename(is_kallsyms, is_vdso, 289 is_debug)); 290 if (ret < 0 || (!alloc && size < (unsigned int)ret)) 291 bf = NULL; 292 free(linkname); 293 294 return bf; 295 } 296 297 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size, 298 bool is_debug) 299 { 300 bool is_kallsyms = dso__is_kallsyms((struct dso *)dso); 301 302 return __dso__build_id_filename(dso, bf, size, is_debug, is_kallsyms); 303 } 304 305 static int write_buildid(const char *name, size_t name_len, struct build_id *bid, 306 pid_t pid, u16 misc, struct feat_fd *fd) 307 { 308 int err; 309 struct perf_record_header_build_id b; 310 size_t len; 311 312 len = name_len + 1; 313 len = PERF_ALIGN(len, NAME_ALIGN); 314 315 memset(&b, 0, sizeof(b)); 316 memcpy(&b.data, bid->data, bid->size); 317 b.size = (u8) bid->size; 318 misc |= PERF_RECORD_MISC_BUILD_ID_SIZE; 319 b.pid = pid; 320 b.header.misc = misc; 321 b.header.size = sizeof(b) + len; 322 323 err = do_write(fd, &b, sizeof(b)); 324 if (err < 0) 325 return err; 326 327 return write_padded(fd, name, name_len + 1, len); 328 } 329 330 static int machine__write_buildid_table(struct machine *machine, 331 struct feat_fd *fd) 332 { 333 int err = 0; 334 struct dso *pos; 335 u16 kmisc = PERF_RECORD_MISC_KERNEL, 336 umisc = PERF_RECORD_MISC_USER; 337 338 if (!machine__is_host(machine)) { 339 kmisc = PERF_RECORD_MISC_GUEST_KERNEL; 340 umisc = PERF_RECORD_MISC_GUEST_USER; 341 } 342 343 dsos__for_each_with_build_id(pos, &machine->dsos.head) { 344 const char *name; 345 size_t name_len; 346 bool in_kernel = false; 347 348 if (!pos->hit && !dso__is_vdso(pos)) 349 continue; 350 351 if (dso__is_vdso(pos)) { 352 name = pos->short_name; 353 name_len = pos->short_name_len; 354 } else if (dso__is_kcore(pos)) { 355 name = machine->mmap_name; 356 name_len = strlen(name); 357 } else { 358 name = pos->long_name; 359 name_len = pos->long_name_len; 360 } 361 362 in_kernel = pos->kernel || 363 is_kernel_module(name, 364 PERF_RECORD_MISC_CPUMODE_UNKNOWN); 365 err = write_buildid(name, name_len, &pos->bid, machine->pid, 366 in_kernel ? kmisc : umisc, fd); 367 if (err) 368 break; 369 } 370 371 return err; 372 } 373 374 int perf_session__write_buildid_table(struct perf_session *session, 375 struct feat_fd *fd) 376 { 377 struct rb_node *nd; 378 int err = machine__write_buildid_table(&session->machines.host, fd); 379 380 if (err) 381 return err; 382 383 for (nd = rb_first_cached(&session->machines.guests); nd; 384 nd = rb_next(nd)) { 385 struct machine *pos = rb_entry(nd, struct machine, rb_node); 386 err = machine__write_buildid_table(pos, fd); 387 if (err) 388 break; 389 } 390 return err; 391 } 392 393 static int __dsos__hit_all(struct list_head *head) 394 { 395 struct dso *pos; 396 397 list_for_each_entry(pos, head, node) 398 pos->hit = true; 399 400 return 0; 401 } 402 403 static int machine__hit_all_dsos(struct machine *machine) 404 { 405 return __dsos__hit_all(&machine->dsos.head); 406 } 407 408 int dsos__hit_all(struct perf_session *session) 409 { 410 struct rb_node *nd; 411 int err; 412 413 err = machine__hit_all_dsos(&session->machines.host); 414 if (err) 415 return err; 416 417 for (nd = rb_first_cached(&session->machines.guests); nd; 418 nd = rb_next(nd)) { 419 struct machine *pos = rb_entry(nd, struct machine, rb_node); 420 421 err = machine__hit_all_dsos(pos); 422 if (err) 423 return err; 424 } 425 426 return 0; 427 } 428 429 void disable_buildid_cache(void) 430 { 431 no_buildid_cache = true; 432 } 433 434 static bool lsdir_bid_head_filter(const char *name __maybe_unused, 435 struct dirent *d) 436 { 437 return (strlen(d->d_name) == 2) && 438 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]); 439 } 440 441 static bool lsdir_bid_tail_filter(const char *name __maybe_unused, 442 struct dirent *d) 443 { 444 int i = 0; 445 while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3) 446 i++; 447 return (i >= SBUILD_ID_MIN_SIZE - 3) && (i <= SBUILD_ID_SIZE - 3) && 448 (d->d_name[i] == '\0'); 449 } 450 451 struct strlist *build_id_cache__list_all(bool validonly) 452 { 453 struct strlist *toplist, *linklist = NULL, *bidlist; 454 struct str_node *nd, *nd2; 455 char *topdir, *linkdir = NULL; 456 char sbuild_id[SBUILD_ID_SIZE]; 457 458 /* for filename__ functions */ 459 if (validonly) 460 symbol__init(NULL); 461 462 /* Open the top-level directory */ 463 if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0) 464 return NULL; 465 466 bidlist = strlist__new(NULL, NULL); 467 if (!bidlist) 468 goto out; 469 470 toplist = lsdir(topdir, lsdir_bid_head_filter); 471 if (!toplist) { 472 pr_debug("Error in lsdir(%s): %d\n", topdir, errno); 473 /* If there is no buildid cache, return an empty list */ 474 if (errno == ENOENT) 475 goto out; 476 goto err_out; 477 } 478 479 strlist__for_each_entry(nd, toplist) { 480 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0) 481 goto err_out; 482 /* Open the lower-level directory */ 483 linklist = lsdir(linkdir, lsdir_bid_tail_filter); 484 if (!linklist) { 485 pr_debug("Error in lsdir(%s): %d\n", linkdir, errno); 486 goto err_out; 487 } 488 strlist__for_each_entry(nd2, linklist) { 489 if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s", 490 nd->s, nd2->s) > SBUILD_ID_SIZE - 1) 491 goto err_out; 492 if (validonly && !build_id_cache__valid_id(sbuild_id)) 493 continue; 494 if (strlist__add(bidlist, sbuild_id) < 0) 495 goto err_out; 496 } 497 strlist__delete(linklist); 498 zfree(&linkdir); 499 } 500 501 out_free: 502 strlist__delete(toplist); 503 out: 504 free(topdir); 505 506 return bidlist; 507 508 err_out: 509 strlist__delete(linklist); 510 zfree(&linkdir); 511 strlist__delete(bidlist); 512 bidlist = NULL; 513 goto out_free; 514 } 515 516 static bool str_is_build_id(const char *maybe_sbuild_id, size_t len) 517 { 518 size_t i; 519 520 for (i = 0; i < len; i++) { 521 if (!isxdigit(maybe_sbuild_id[i])) 522 return false; 523 } 524 return true; 525 } 526 527 /* Return the valid complete build-id */ 528 char *build_id_cache__complement(const char *incomplete_sbuild_id) 529 { 530 struct strlist *bidlist; 531 struct str_node *nd, *cand = NULL; 532 char *sbuild_id = NULL; 533 size_t len = strlen(incomplete_sbuild_id); 534 535 if (len >= SBUILD_ID_SIZE || 536 !str_is_build_id(incomplete_sbuild_id, len)) 537 return NULL; 538 539 bidlist = build_id_cache__list_all(true); 540 if (!bidlist) 541 return NULL; 542 543 strlist__for_each_entry(nd, bidlist) { 544 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0) 545 continue; 546 if (cand) { /* Error: There are more than 2 candidates. */ 547 cand = NULL; 548 break; 549 } 550 cand = nd; 551 } 552 if (cand) 553 sbuild_id = strdup(cand->s); 554 strlist__delete(bidlist); 555 556 return sbuild_id; 557 } 558 559 char *build_id_cache__cachedir(const char *sbuild_id, const char *name, 560 struct nsinfo *nsi, bool is_kallsyms, 561 bool is_vdso) 562 { 563 char *realname = (char *)name, *filename; 564 bool slash = is_kallsyms || is_vdso; 565 566 if (!slash) 567 realname = nsinfo__realpath(name, nsi); 568 569 if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "", 570 is_vdso ? DSO__NAME_VDSO : (realname ? realname : name), 571 sbuild_id ? "/" : "", sbuild_id ?: "") < 0) 572 filename = NULL; 573 574 if (!slash) 575 free(realname); 576 577 return filename; 578 } 579 580 int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi, 581 struct strlist **result) 582 { 583 char *dir_name; 584 int ret = 0; 585 586 dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false); 587 if (!dir_name) 588 return -ENOMEM; 589 590 *result = lsdir(dir_name, lsdir_no_dot_filter); 591 if (!*result) 592 ret = -errno; 593 free(dir_name); 594 595 return ret; 596 } 597 598 #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT) 599 static int build_id_cache__add_sdt_cache(const char *sbuild_id, 600 const char *realname, 601 struct nsinfo *nsi) 602 { 603 struct probe_cache *cache; 604 int ret; 605 struct nscookie nsc; 606 607 cache = probe_cache__new(sbuild_id, nsi); 608 if (!cache) 609 return -1; 610 611 nsinfo__mountns_enter(nsi, &nsc); 612 ret = probe_cache__scan_sdt(cache, realname); 613 nsinfo__mountns_exit(&nsc); 614 if (ret >= 0) { 615 pr_debug4("Found %d SDTs in %s\n", ret, realname); 616 if (probe_cache__commit(cache) < 0) 617 ret = -1; 618 } 619 probe_cache__delete(cache); 620 return ret; 621 } 622 #else 623 #define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0) 624 #endif 625 626 static char *build_id_cache__find_debug(const char *sbuild_id, 627 struct nsinfo *nsi, 628 const char *root_dir) 629 { 630 const char *dirname = "/usr/lib/debug/.build-id/"; 631 char *realname = NULL; 632 char dirbuf[PATH_MAX]; 633 char *debugfile; 634 struct nscookie nsc; 635 size_t len = 0; 636 637 debugfile = calloc(1, PATH_MAX); 638 if (!debugfile) 639 goto out; 640 641 if (root_dir) { 642 path__join(dirbuf, PATH_MAX, root_dir, dirname); 643 dirname = dirbuf; 644 } 645 646 len = __symbol__join_symfs(debugfile, PATH_MAX, dirname); 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; 659 660 pr_debug("Downloading debug info with build id %s\n", sbuild_id); 661 662 c = debuginfod_begin(); 663 if (c != NULL) { 664 int fd = debuginfod_find_debuginfo(c, 665 (const unsigned char*)sbuild_id, 0, 666 &realname); 667 if (fd >= 0) 668 close(fd); /* retaining reference by realname */ 669 debuginfod_end(c); 670 } 671 } 672 #endif 673 674 out: 675 free(debugfile); 676 return realname; 677 } 678 679 int 680 build_id_cache__add(const char *sbuild_id, const char *name, const char *realname, 681 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso, 682 const char *proper_name, const char *root_dir) 683 { 684 const size_t size = PATH_MAX; 685 char *filename = NULL, *dir_name = NULL, *linkname = zalloc(size), *tmp; 686 char *debugfile = NULL; 687 int err = -1; 688 689 if (!proper_name) 690 proper_name = name; 691 692 dir_name = build_id_cache__cachedir(sbuild_id, proper_name, nsi, is_kallsyms, 693 is_vdso); 694 if (!dir_name) 695 goto out_free; 696 697 /* Remove old style build-id cache */ 698 if (is_regular_file(dir_name)) 699 if (unlink(dir_name)) 700 goto out_free; 701 702 if (mkdir_p(dir_name, 0755)) 703 goto out_free; 704 705 /* Save the allocated buildid dirname */ 706 if (asprintf(&filename, "%s/%s", dir_name, 707 build_id_cache__basename(is_kallsyms, is_vdso, 708 false)) < 0) { 709 filename = NULL; 710 goto out_free; 711 } 712 713 if (access(filename, F_OK)) { 714 if (is_kallsyms) { 715 if (copyfile("/proc/kallsyms", filename)) 716 goto out_free; 717 } else if (nsi && nsinfo__need_setns(nsi)) { 718 if (copyfile_ns(name, filename, nsi)) 719 goto out_free; 720 } else if (link(realname, filename) && errno != EEXIST) { 721 struct stat f_stat; 722 723 if (!(stat(name, &f_stat) < 0) && 724 copyfile_mode(name, filename, f_stat.st_mode)) 725 goto out_free; 726 } 727 } 728 729 /* Some binaries are stripped, but have .debug files with their symbol 730 * table. Check to see if we can locate one of those, since the elf 731 * file itself may not be very useful to users of our tools without a 732 * symtab. 733 */ 734 if (!is_kallsyms && !is_vdso && 735 strncmp(".ko", name + strlen(name) - 3, 3)) { 736 debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir); 737 if (debugfile) { 738 zfree(&filename); 739 if (asprintf(&filename, "%s/%s", dir_name, 740 build_id_cache__basename(false, false, true)) < 0) { 741 filename = NULL; 742 goto out_free; 743 } 744 if (access(filename, F_OK)) { 745 if (nsi && nsinfo__need_setns(nsi)) { 746 if (copyfile_ns(debugfile, filename, 747 nsi)) 748 goto out_free; 749 } else if (link(debugfile, filename) && 750 errno != EEXIST && 751 copyfile(debugfile, filename)) 752 goto out_free; 753 } 754 } 755 } 756 757 if (!build_id_cache__linkname(sbuild_id, linkname, size)) 758 goto out_free; 759 tmp = strrchr(linkname, '/'); 760 *tmp = '\0'; 761 762 if (access(linkname, X_OK) && mkdir_p(linkname, 0755)) 763 goto out_free; 764 765 *tmp = '/'; 766 tmp = dir_name + strlen(buildid_dir) - 5; 767 memcpy(tmp, "../..", 5); 768 769 if (symlink(tmp, linkname) == 0) { 770 err = 0; 771 } else if (errno == EEXIST) { 772 char path[PATH_MAX]; 773 ssize_t len; 774 775 len = readlink(linkname, path, sizeof(path) - 1); 776 if (len <= 0) { 777 pr_err("Can't read link: %s\n", linkname); 778 goto out_free; 779 } 780 path[len] = '\0'; 781 782 if (strcmp(tmp, path)) { 783 pr_debug("build <%s> already linked to %s\n", 784 sbuild_id, linkname); 785 } 786 err = 0; 787 } 788 789 /* Update SDT cache : error is just warned */ 790 if (realname && 791 build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0) 792 pr_debug4("Failed to update/scan SDT cache for %s\n", realname); 793 794 out_free: 795 free(filename); 796 free(debugfile); 797 free(dir_name); 798 free(linkname); 799 return err; 800 } 801 802 int __build_id_cache__add_s(const char *sbuild_id, const char *name, 803 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso, 804 const char *proper_name, const char *root_dir) 805 { 806 char *realname = NULL; 807 int err = -1; 808 809 if (!is_kallsyms) { 810 if (!is_vdso) 811 realname = nsinfo__realpath(name, nsi); 812 else 813 realname = realpath(name, NULL); 814 if (!realname) 815 goto out_free; 816 } 817 818 err = build_id_cache__add(sbuild_id, name, realname, nsi, 819 is_kallsyms, is_vdso, proper_name, root_dir); 820 out_free: 821 if (!is_kallsyms) 822 free(realname); 823 return err; 824 } 825 826 static int build_id_cache__add_b(const struct build_id *bid, 827 const char *name, struct nsinfo *nsi, 828 bool is_kallsyms, bool is_vdso, 829 const char *proper_name, 830 const char *root_dir) 831 { 832 char sbuild_id[SBUILD_ID_SIZE]; 833 834 build_id__sprintf(bid, sbuild_id); 835 836 return __build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms, 837 is_vdso, proper_name, root_dir); 838 } 839 840 bool build_id_cache__cached(const char *sbuild_id) 841 { 842 bool ret = false; 843 char *filename = build_id_cache__linkname(sbuild_id, NULL, 0); 844 845 if (filename && !access(filename, F_OK)) 846 ret = true; 847 free(filename); 848 849 return ret; 850 } 851 852 int build_id_cache__remove_s(const char *sbuild_id) 853 { 854 const size_t size = PATH_MAX; 855 char *filename = zalloc(size), 856 *linkname = zalloc(size), *tmp; 857 int err = -1; 858 859 if (filename == NULL || linkname == NULL) 860 goto out_free; 861 862 if (!build_id_cache__linkname(sbuild_id, linkname, size)) 863 goto out_free; 864 865 if (access(linkname, F_OK)) 866 goto out_free; 867 868 if (readlink(linkname, filename, size - 1) < 0) 869 goto out_free; 870 871 if (unlink(linkname)) 872 goto out_free; 873 874 /* 875 * Since the link is relative, we must make it absolute: 876 */ 877 tmp = strrchr(linkname, '/') + 1; 878 snprintf(tmp, size - (tmp - linkname), "%s", filename); 879 880 if (rm_rf(linkname)) 881 goto out_free; 882 883 err = 0; 884 out_free: 885 free(filename); 886 free(linkname); 887 return err; 888 } 889 890 static int filename__read_build_id_ns(const char *filename, 891 struct build_id *bid, 892 struct nsinfo *nsi) 893 { 894 struct nscookie nsc; 895 int ret; 896 897 nsinfo__mountns_enter(nsi, &nsc); 898 ret = filename__read_build_id(filename, bid); 899 nsinfo__mountns_exit(&nsc); 900 901 return ret; 902 } 903 904 static bool dso__build_id_mismatch(struct dso *dso, const char *name) 905 { 906 struct build_id bid; 907 bool ret = false; 908 909 mutex_lock(&dso->lock); 910 if (filename__read_build_id_ns(name, &bid, dso->nsinfo) >= 0) 911 ret = !dso__build_id_equal(dso, &bid); 912 913 mutex_unlock(&dso->lock); 914 915 return ret; 916 } 917 918 static int dso__cache_build_id(struct dso *dso, struct machine *machine, 919 void *priv __maybe_unused) 920 { 921 bool is_kallsyms = dso__is_kallsyms(dso); 922 bool is_vdso = dso__is_vdso(dso); 923 const char *name = dso->long_name; 924 const char *proper_name = NULL; 925 const char *root_dir = NULL; 926 char *allocated_name = NULL; 927 int ret = 0; 928 929 if (!dso->has_build_id) 930 return 0; 931 932 if (dso__is_kcore(dso)) { 933 is_kallsyms = true; 934 name = machine->mmap_name; 935 } 936 937 if (!machine__is_host(machine)) { 938 if (*machine->root_dir) { 939 root_dir = machine->root_dir; 940 ret = asprintf(&allocated_name, "%s/%s", root_dir, name); 941 if (ret < 0) 942 return ret; 943 proper_name = name; 944 name = allocated_name; 945 } else if (is_kallsyms) { 946 /* Cannot get guest kallsyms */ 947 return 0; 948 } 949 } 950 951 if (!is_kallsyms && dso__build_id_mismatch(dso, name)) 952 goto out_free; 953 954 mutex_lock(&dso->lock); 955 ret = build_id_cache__add_b(&dso->bid, name, dso->nsinfo, 956 is_kallsyms, is_vdso, proper_name, root_dir); 957 mutex_unlock(&dso->lock); 958 out_free: 959 free(allocated_name); 960 return ret; 961 } 962 963 static int 964 machines__for_each_dso(struct machines *machines, machine__dso_t fn, void *priv) 965 { 966 int ret = machine__for_each_dso(&machines->host, fn, priv); 967 struct rb_node *nd; 968 969 for (nd = rb_first_cached(&machines->guests); nd; 970 nd = rb_next(nd)) { 971 struct machine *pos = rb_entry(nd, struct machine, rb_node); 972 973 ret |= machine__for_each_dso(pos, fn, priv); 974 } 975 return ret ? -1 : 0; 976 } 977 978 int __perf_session__cache_build_ids(struct perf_session *session, 979 machine__dso_t fn, void *priv) 980 { 981 if (no_buildid_cache) 982 return 0; 983 984 if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST) 985 return -1; 986 987 return machines__for_each_dso(&session->machines, fn, priv) ? -1 : 0; 988 } 989 990 int perf_session__cache_build_ids(struct perf_session *session) 991 { 992 return __perf_session__cache_build_ids(session, dso__cache_build_id, NULL); 993 } 994 995 static bool machine__read_build_ids(struct machine *machine, bool with_hits) 996 { 997 return __dsos__read_build_ids(&machine->dsos.head, with_hits); 998 } 999 1000 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits) 1001 { 1002 struct rb_node *nd; 1003 bool ret = machine__read_build_ids(&session->machines.host, with_hits); 1004 1005 for (nd = rb_first_cached(&session->machines.guests); nd; 1006 nd = rb_next(nd)) { 1007 struct machine *pos = rb_entry(nd, struct machine, rb_node); 1008 ret |= machine__read_build_ids(pos, with_hits); 1009 } 1010 1011 return ret; 1012 } 1013 1014 void build_id__init(struct build_id *bid, const u8 *data, size_t size) 1015 { 1016 WARN_ON(size > BUILD_ID_SIZE); 1017 memcpy(bid->data, data, size); 1018 bid->size = size; 1019 } 1020 1021 bool build_id__is_defined(const struct build_id *bid) 1022 { 1023 return bid && bid->size ? !!memchr_inv(bid->data, 0, bid->size) : false; 1024 } 1025