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 static int mark_dso_hit_callback(struct callchain_cursor_node *node, void *data __maybe_unused) 46 { 47 struct map *map = node->ms.map; 48 49 if (map) 50 dso__set_hit(map__dso(map)); 51 52 return 0; 53 } 54 55 int build_id__mark_dso_hit(const struct perf_tool *tool __maybe_unused, 56 union perf_event *event, 57 struct perf_sample *sample, 58 struct evsel *evsel, 59 struct machine *machine) 60 { 61 struct addr_location al; 62 struct thread *thread = machine__findnew_thread(machine, sample->pid, 63 sample->tid); 64 65 if (thread == NULL) { 66 pr_err("problem processing %d event, skipping it.\n", 67 event->header.type); 68 return -1; 69 } 70 71 addr_location__init(&al); 72 if (thread__find_map(thread, sample->cpumode, sample->ip, &al)) 73 dso__set_hit(map__dso(al.map)); 74 75 addr_location__exit(&al); 76 77 sample__for_each_callchain_node(thread, evsel, sample, PERF_MAX_STACK_DEPTH, 78 /*symbols=*/false, mark_dso_hit_callback, /*data=*/NULL); 79 80 81 thread__put(thread); 82 return 0; 83 } 84 85 int build_id__snprintf(const struct build_id *build_id, char *bf, size_t bf_size) 86 { 87 size_t offs = 0; 88 89 if (build_id->size == 0) { 90 /* Ensure bf is always \0 terminated. */ 91 if (bf_size > 0) 92 bf[0] = '\0'; 93 return 0; 94 } 95 96 for (size_t i = 0; i < build_id->size && offs < bf_size; ++i) 97 offs += snprintf(bf + offs, bf_size - offs, "%02x", build_id->data[i]); 98 99 return offs; 100 } 101 102 int sysfs__snprintf_build_id(const char *root_dir, char *sbuild_id, size_t sbuild_id_size) 103 { 104 char notes[PATH_MAX]; 105 struct build_id bid = { .size = 0, }; 106 int ret; 107 108 if (!root_dir) 109 root_dir = ""; 110 111 scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir); 112 113 ret = sysfs__read_build_id(notes, &bid); 114 if (ret < 0) 115 return ret; 116 117 return build_id__snprintf(&bid, sbuild_id, sbuild_id_size); 118 } 119 120 int filename__snprintf_build_id(const char *pathname, char *sbuild_id, size_t sbuild_id_size) 121 { 122 struct build_id bid = { .size = 0, }; 123 int ret; 124 125 ret = filename__read_build_id(pathname, &bid, /*block=*/true); 126 if (ret < 0) 127 return ret; 128 129 return build_id__snprintf(&bid, sbuild_id, sbuild_id_size); 130 } 131 132 /* asnprintf consolidates asprintf and snprintf */ 133 static int asnprintf(char **strp, size_t size, const char *fmt, ...) 134 { 135 va_list ap; 136 int ret; 137 138 if (!strp) 139 return -EINVAL; 140 141 va_start(ap, fmt); 142 if (*strp) 143 ret = vsnprintf(*strp, size, fmt, ap); 144 else 145 ret = vasprintf(strp, fmt, ap); 146 va_end(ap); 147 148 return ret; 149 } 150 151 char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf, 152 size_t size) 153 { 154 bool retry_old = true; 155 156 snprintf(bf, size, "%s/%s/%s/kallsyms", 157 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); 158 retry: 159 if (!access(bf, F_OK)) 160 return bf; 161 if (retry_old) { 162 /* Try old style kallsyms cache */ 163 snprintf(bf, size, "%s/%s/%s", 164 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); 165 retry_old = false; 166 goto retry; 167 } 168 169 return NULL; 170 } 171 172 char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size) 173 { 174 char *tmp = bf; 175 int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir, 176 sbuild_id, sbuild_id + 2); 177 if (ret < 0 || (tmp && size < (unsigned int)ret)) 178 return NULL; 179 return bf; 180 } 181 182 /* The caller is responsible to free the returned buffer. */ 183 char *build_id_cache__origname(const char *sbuild_id) 184 { 185 char *linkname; 186 char buf[PATH_MAX]; 187 char *ret = NULL, *p; 188 size_t offs = 5; /* == strlen("../..") */ 189 ssize_t len; 190 191 linkname = build_id_cache__linkname(sbuild_id, NULL, 0); 192 if (!linkname) 193 return NULL; 194 195 len = readlink(linkname, buf, sizeof(buf) - 1); 196 if (len <= 0) 197 goto out; 198 buf[len] = '\0'; 199 200 /* The link should be "../..<origpath>/<sbuild_id>" */ 201 p = strrchr(buf, '/'); /* Cut off the "/<sbuild_id>" */ 202 if (p && (p > buf + offs)) { 203 *p = '\0'; 204 if (buf[offs + 1] == '[') 205 offs++; /* 206 * This is a DSO name, like [kernel.kallsyms]. 207 * Skip the first '/', since this is not the 208 * cache of a regular file. 209 */ 210 ret = strdup(buf + offs); /* Skip "../..[/]" */ 211 } 212 out: 213 free(linkname); 214 return ret; 215 } 216 217 /* Check if the given build_id cache is valid on current running system */ 218 static bool build_id_cache__valid_id(char *sbuild_id) 219 { 220 char real_sbuild_id[SBUILD_ID_SIZE] = ""; 221 char *pathname; 222 int ret = 0; 223 bool result = false; 224 225 pathname = build_id_cache__origname(sbuild_id); 226 if (!pathname) 227 return false; 228 229 if (!strcmp(pathname, DSO__NAME_KALLSYMS)) 230 ret = sysfs__snprintf_build_id("/", real_sbuild_id, sizeof(real_sbuild_id)); 231 else if (pathname[0] == '/') 232 ret = filename__snprintf_build_id(pathname, real_sbuild_id, sizeof(real_sbuild_id)); 233 else 234 ret = -EINVAL; /* Should we support other special DSO cache? */ 235 if (ret >= 0) 236 result = (strcmp(sbuild_id, real_sbuild_id) == 0); 237 free(pathname); 238 239 return result; 240 } 241 242 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso, 243 bool is_debug) 244 { 245 return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ? 246 "debug" : "elf")); 247 } 248 249 char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size, 250 bool is_debug, bool is_kallsyms) 251 { 252 bool is_vdso = dso__is_vdso((struct dso *)dso); 253 char sbuild_id[SBUILD_ID_SIZE]; 254 char *linkname; 255 bool alloc = (bf == NULL); 256 int ret; 257 258 if (!dso__has_build_id(dso)) 259 return NULL; 260 261 build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id)); 262 linkname = build_id_cache__linkname(sbuild_id, NULL, 0); 263 if (!linkname) 264 return NULL; 265 266 /* Check if old style build_id cache */ 267 if (is_regular_file(linkname)) 268 ret = asnprintf(&bf, size, "%s", linkname); 269 else 270 ret = asnprintf(&bf, size, "%s/%s", linkname, 271 build_id_cache__basename(is_kallsyms, is_vdso, 272 is_debug)); 273 if (ret < 0 || (!alloc && size < (unsigned int)ret)) 274 bf = NULL; 275 free(linkname); 276 277 return bf; 278 } 279 280 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size, 281 bool is_debug) 282 { 283 bool is_kallsyms = dso__is_kallsyms((struct dso *)dso); 284 285 return __dso__build_id_filename(dso, bf, size, is_debug, is_kallsyms); 286 } 287 288 static int write_buildid(const char *name, size_t name_len, struct build_id *bid, 289 pid_t pid, u16 misc, struct feat_fd *fd) 290 { 291 int err; 292 struct perf_record_header_build_id b; 293 size_t len; 294 295 len = name_len + 1; 296 len = PERF_ALIGN(len, sizeof(u64)); 297 298 memset(&b, 0, sizeof(b)); 299 memcpy(&b.data, bid->data, bid->size); 300 b.size = (u8) bid->size; 301 misc |= PERF_RECORD_MISC_BUILD_ID_SIZE; 302 b.pid = pid; 303 b.header.misc = misc; 304 b.header.size = sizeof(b) + len; 305 306 err = do_write(fd, &b, sizeof(b)); 307 if (err < 0) 308 return err; 309 310 return write_padded(fd, name, name_len + 1, len); 311 } 312 313 struct machine__write_buildid_table_cb_args { 314 struct machine *machine; 315 struct feat_fd *fd; 316 u16 kmisc, umisc; 317 }; 318 319 static int machine__write_buildid_table_cb(struct dso *dso, void *data) 320 { 321 struct machine__write_buildid_table_cb_args *args = data; 322 const char *name; 323 size_t name_len; 324 bool in_kernel = false; 325 326 if (!dso__has_build_id(dso)) 327 return 0; 328 329 if (!dso__hit(dso) && !dso__is_vdso(dso)) 330 return 0; 331 332 if (dso__is_vdso(dso)) { 333 name = dso__short_name(dso); 334 name_len = dso__short_name_len(dso); 335 } else if (dso__is_kcore(dso)) { 336 name = args->machine->mmap_name; 337 name_len = strlen(name); 338 } else { 339 name = dso__long_name(dso); 340 name_len = dso__long_name_len(dso); 341 } 342 343 in_kernel = dso__kernel(dso) || is_kernel_module(name, PERF_RECORD_MISC_CPUMODE_UNKNOWN); 344 return write_buildid(name, name_len, &dso__id(dso)->build_id, args->machine->pid, 345 in_kernel ? args->kmisc : args->umisc, args->fd); 346 } 347 348 static int machine__write_buildid_table(struct machine *machine, struct feat_fd *fd) 349 { 350 struct machine__write_buildid_table_cb_args args = { 351 .machine = machine, 352 .fd = fd, 353 .kmisc = PERF_RECORD_MISC_KERNEL, 354 .umisc = PERF_RECORD_MISC_USER, 355 }; 356 357 if (!machine__is_host(machine)) { 358 args.kmisc = PERF_RECORD_MISC_GUEST_KERNEL; 359 args.umisc = PERF_RECORD_MISC_GUEST_USER; 360 } 361 362 return dsos__for_each_dso(&machine->dsos, machine__write_buildid_table_cb, &args); 363 } 364 365 int perf_session__write_buildid_table(struct perf_session *session, 366 struct feat_fd *fd) 367 { 368 struct rb_node *nd; 369 int err = machine__write_buildid_table(&session->machines.host, fd); 370 371 if (err) 372 return err; 373 374 for (nd = rb_first_cached(&session->machines.guests); nd; 375 nd = rb_next(nd)) { 376 struct machine *pos = rb_entry(nd, struct machine, rb_node); 377 err = machine__write_buildid_table(pos, fd); 378 if (err) 379 break; 380 } 381 return err; 382 } 383 384 void disable_buildid_cache(void) 385 { 386 no_buildid_cache = true; 387 } 388 389 static bool lsdir_bid_head_filter(const char *name __maybe_unused, 390 struct dirent *d) 391 { 392 return (strlen(d->d_name) == 2) && 393 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]); 394 } 395 396 static bool lsdir_bid_tail_filter(const char *name __maybe_unused, 397 struct dirent *d) 398 { 399 int i = 0; 400 while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3) 401 i++; 402 return (i >= SBUILD_ID_MIN_SIZE - 3) && (i <= SBUILD_ID_SIZE - 3) && 403 (d->d_name[i] == '\0'); 404 } 405 406 struct strlist *build_id_cache__list_all(bool validonly) 407 { 408 struct strlist *toplist, *linklist = NULL, *bidlist; 409 struct str_node *nd, *nd2; 410 char *topdir, *linkdir = NULL; 411 char sbuild_id[SBUILD_ID_SIZE]; 412 413 /* for filename__ functions */ 414 if (validonly) 415 symbol__init(NULL); 416 417 /* Open the top-level directory */ 418 if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0) 419 return NULL; 420 421 bidlist = strlist__new(NULL, NULL); 422 if (!bidlist) 423 goto out; 424 425 toplist = lsdir(topdir, lsdir_bid_head_filter); 426 if (!toplist) { 427 pr_debug("Error in lsdir(%s): %d\n", topdir, errno); 428 /* If there is no buildid cache, return an empty list */ 429 if (errno == ENOENT) 430 goto out; 431 goto err_out; 432 } 433 434 strlist__for_each_entry(nd, toplist) { 435 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0) 436 goto err_out; 437 /* Open the lower-level directory */ 438 linklist = lsdir(linkdir, lsdir_bid_tail_filter); 439 if (!linklist) { 440 pr_debug("Error in lsdir(%s): %d\n", linkdir, errno); 441 goto err_out; 442 } 443 strlist__for_each_entry(nd2, linklist) { 444 if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s", 445 nd->s, nd2->s) > SBUILD_ID_SIZE - 1) 446 goto err_out; 447 if (validonly && !build_id_cache__valid_id(sbuild_id)) 448 continue; 449 if (strlist__add(bidlist, sbuild_id) < 0) 450 goto err_out; 451 } 452 strlist__delete(linklist); 453 zfree(&linkdir); 454 } 455 456 out_free: 457 strlist__delete(toplist); 458 out: 459 free(topdir); 460 461 return bidlist; 462 463 err_out: 464 strlist__delete(linklist); 465 zfree(&linkdir); 466 strlist__delete(bidlist); 467 bidlist = NULL; 468 goto out_free; 469 } 470 471 static bool str_is_build_id(const char *maybe_sbuild_id, size_t len) 472 { 473 size_t i; 474 475 for (i = 0; i < len; i++) { 476 if (!isxdigit(maybe_sbuild_id[i])) 477 return false; 478 } 479 return true; 480 } 481 482 /* Return the valid complete build-id */ 483 char *build_id_cache__complement(const char *incomplete_sbuild_id) 484 { 485 struct strlist *bidlist; 486 struct str_node *nd, *cand = NULL; 487 char *sbuild_id = NULL; 488 size_t len = strlen(incomplete_sbuild_id); 489 490 if (len >= SBUILD_ID_SIZE || 491 !str_is_build_id(incomplete_sbuild_id, len)) 492 return NULL; 493 494 bidlist = build_id_cache__list_all(true); 495 if (!bidlist) 496 return NULL; 497 498 strlist__for_each_entry(nd, bidlist) { 499 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0) 500 continue; 501 if (cand) { /* Error: There are more than 2 candidates. */ 502 cand = NULL; 503 break; 504 } 505 cand = nd; 506 } 507 if (cand) 508 sbuild_id = strdup(cand->s); 509 strlist__delete(bidlist); 510 511 return sbuild_id; 512 } 513 514 char *build_id_cache__cachedir(const char *sbuild_id, const char *name, 515 struct nsinfo *nsi, bool is_kallsyms, 516 bool is_vdso) 517 { 518 char *realname = NULL, *filename; 519 bool slash = is_kallsyms || is_vdso; 520 521 if (!slash) 522 realname = nsinfo__realpath(name, nsi); 523 524 if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "", 525 is_vdso ? DSO__NAME_VDSO : (realname ? realname : name), 526 sbuild_id ? "/" : "", sbuild_id ?: "") < 0) 527 filename = NULL; 528 529 free(realname); 530 return filename; 531 } 532 533 int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi, 534 struct strlist **result) 535 { 536 char *dir_name; 537 int ret = 0; 538 539 dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false); 540 if (!dir_name) 541 return -ENOMEM; 542 543 *result = lsdir(dir_name, lsdir_no_dot_filter); 544 if (!*result) 545 ret = -errno; 546 free(dir_name); 547 548 return ret; 549 } 550 551 #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT) 552 static int build_id_cache__add_sdt_cache(const char *sbuild_id, 553 const char *realname, 554 struct nsinfo *nsi) 555 { 556 struct probe_cache *cache; 557 int ret; 558 struct nscookie nsc; 559 560 cache = probe_cache__new(sbuild_id, nsi); 561 if (!cache) 562 return -1; 563 564 nsinfo__mountns_enter(nsi, &nsc); 565 ret = probe_cache__scan_sdt(cache, realname); 566 nsinfo__mountns_exit(&nsc); 567 if (ret >= 0) { 568 pr_debug4("Found %d SDTs in %s\n", ret, realname); 569 if (probe_cache__commit(cache) < 0) 570 ret = -1; 571 } 572 probe_cache__delete(cache); 573 return ret; 574 } 575 #else 576 #define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0) 577 #endif 578 579 static char *build_id_cache__find_debug(const char *sbuild_id, 580 struct nsinfo *nsi, 581 const char *root_dir) 582 { 583 const char *dirname = "/usr/lib/debug/.build-id/"; 584 char *realname = NULL; 585 char dirbuf[PATH_MAX]; 586 char *debugfile; 587 struct nscookie nsc; 588 size_t len = 0; 589 590 debugfile = calloc(1, PATH_MAX); 591 if (!debugfile) 592 goto out; 593 594 if (root_dir) { 595 path__join(dirbuf, PATH_MAX, root_dir, dirname); 596 dirname = dirbuf; 597 } 598 599 len = __symbol__join_symfs(debugfile, PATH_MAX, dirname); 600 snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id, 601 sbuild_id + 2); 602 603 nsinfo__mountns_enter(nsi, &nsc); 604 realname = realpath(debugfile, NULL); 605 if (realname && access(realname, R_OK)) 606 zfree(&realname); 607 nsinfo__mountns_exit(&nsc); 608 609 #ifdef HAVE_DEBUGINFOD_SUPPORT 610 if (realname == NULL) { 611 debuginfod_client* c; 612 613 pr_debug("Downloading debug info with build id %s\n", sbuild_id); 614 615 c = debuginfod_begin(); 616 if (c != NULL) { 617 int fd = debuginfod_find_debuginfo(c, 618 (const unsigned char*)sbuild_id, 0, 619 &realname); 620 if (fd >= 0) 621 close(fd); /* retaining reference by realname */ 622 debuginfod_end(c); 623 } 624 } 625 #endif 626 627 out: 628 free(debugfile); 629 return realname; 630 } 631 632 int 633 build_id_cache__add(const char *sbuild_id, const char *name, const char *realname, 634 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso, 635 const char *proper_name, const char *root_dir) 636 { 637 const size_t size = PATH_MAX; 638 char *filename = NULL, *dir_name = NULL, *linkname = zalloc(size), *tmp; 639 char *debugfile = NULL; 640 int err = -1; 641 642 if (!proper_name) 643 proper_name = name; 644 645 dir_name = build_id_cache__cachedir(sbuild_id, proper_name, nsi, is_kallsyms, 646 is_vdso); 647 if (!dir_name) 648 goto out_free; 649 650 /* Remove old style build-id cache */ 651 if (is_regular_file(dir_name)) 652 if (unlink(dir_name)) 653 goto out_free; 654 655 if (mkdir_p(dir_name, 0755)) 656 goto out_free; 657 658 /* Save the allocated buildid dirname */ 659 if (asprintf(&filename, "%s/%s", dir_name, 660 build_id_cache__basename(is_kallsyms, is_vdso, 661 false)) < 0) { 662 filename = NULL; 663 goto out_free; 664 } 665 666 if (access(filename, F_OK)) { 667 if (is_kallsyms) { 668 if (copyfile("/proc/kallsyms", filename)) 669 goto out_free; 670 } else if (nsi && nsinfo__need_setns(nsi)) { 671 if (copyfile_ns(name, filename, nsi)) 672 goto out_free; 673 } else if (link(realname, filename) && errno != EEXIST) { 674 struct stat f_stat; 675 676 if (!(stat(name, &f_stat) < 0) && 677 copyfile_mode(name, filename, f_stat.st_mode)) 678 goto out_free; 679 } 680 } 681 682 /* Some binaries are stripped, but have .debug files with their symbol 683 * table. Check to see if we can locate one of those, since the elf 684 * file itself may not be very useful to users of our tools without a 685 * symtab. 686 */ 687 if (!is_kallsyms && !is_vdso && 688 strncmp(".ko", name + strlen(name) - 3, 3)) { 689 debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir); 690 if (debugfile) { 691 zfree(&filename); 692 if (asprintf(&filename, "%s/%s", dir_name, 693 build_id_cache__basename(false, false, true)) < 0) { 694 filename = NULL; 695 goto out_free; 696 } 697 if (access(filename, F_OK)) { 698 if (nsi && nsinfo__need_setns(nsi)) { 699 if (copyfile_ns(debugfile, filename, 700 nsi)) 701 goto out_free; 702 } else if (link(debugfile, filename) && 703 errno != EEXIST && 704 copyfile(debugfile, filename)) 705 goto out_free; 706 } 707 } 708 } 709 710 if (!build_id_cache__linkname(sbuild_id, linkname, size)) 711 goto out_free; 712 tmp = strrchr(linkname, '/'); 713 *tmp = '\0'; 714 715 if (access(linkname, X_OK) && mkdir_p(linkname, 0755)) 716 goto out_free; 717 718 *tmp = '/'; 719 tmp = dir_name + strlen(buildid_dir) - 5; 720 memcpy(tmp, "../..", 5); 721 722 if (symlink(tmp, linkname) == 0) { 723 err = 0; 724 } else if (errno == EEXIST) { 725 char path[PATH_MAX]; 726 ssize_t len; 727 728 len = readlink(linkname, path, sizeof(path) - 1); 729 if (len <= 0) { 730 pr_err("Can't read link: %s\n", linkname); 731 goto out_free; 732 } 733 path[len] = '\0'; 734 735 if (strcmp(tmp, path)) { 736 pr_debug("build <%s> already linked to %s\n", 737 sbuild_id, linkname); 738 } 739 err = 0; 740 } 741 742 /* Update SDT cache : error is just warned */ 743 if (realname && 744 build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0) 745 pr_debug4("Failed to update/scan SDT cache for %s\n", realname); 746 747 out_free: 748 free(filename); 749 free(debugfile); 750 free(dir_name); 751 free(linkname); 752 return err; 753 } 754 755 int __build_id_cache__add_s(const char *sbuild_id, const char *name, 756 struct nsinfo *nsi, bool is_kallsyms, bool is_vdso, 757 const char *proper_name, const char *root_dir) 758 { 759 char *realname = NULL; 760 int err = -1; 761 762 if (!is_kallsyms) { 763 if (!is_vdso) 764 realname = nsinfo__realpath(name, nsi); 765 else 766 realname = realpath(name, NULL); 767 if (!realname) 768 goto out_free; 769 } 770 771 err = build_id_cache__add(sbuild_id, name, realname, nsi, 772 is_kallsyms, is_vdso, proper_name, root_dir); 773 out_free: 774 if (!is_kallsyms) 775 free(realname); 776 return err; 777 } 778 779 static int build_id_cache__add_b(const struct build_id *bid, 780 const char *name, struct nsinfo *nsi, 781 bool is_kallsyms, bool is_vdso, 782 const char *proper_name, 783 const char *root_dir) 784 { 785 char sbuild_id[SBUILD_ID_SIZE]; 786 787 build_id__snprintf(bid, sbuild_id, sizeof(sbuild_id)); 788 789 return __build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms, 790 is_vdso, proper_name, root_dir); 791 } 792 793 bool build_id_cache__cached(const char *sbuild_id) 794 { 795 bool ret = false; 796 char *filename = build_id_cache__linkname(sbuild_id, NULL, 0); 797 798 if (filename && !access(filename, F_OK)) 799 ret = true; 800 free(filename); 801 802 return ret; 803 } 804 805 int build_id_cache__remove_s(const char *sbuild_id) 806 { 807 const size_t size = PATH_MAX; 808 char *filename = zalloc(size), 809 *linkname = zalloc(size), *tmp; 810 int err = -1; 811 812 if (filename == NULL || linkname == NULL) 813 goto out_free; 814 815 if (!build_id_cache__linkname(sbuild_id, linkname, size)) 816 goto out_free; 817 818 if (access(linkname, F_OK)) 819 goto out_free; 820 821 if (readlink(linkname, filename, size - 1) < 0) 822 goto out_free; 823 824 if (unlink(linkname)) 825 goto out_free; 826 827 /* 828 * Since the link is relative, we must make it absolute: 829 */ 830 tmp = strrchr(linkname, '/') + 1; 831 snprintf(tmp, size - (tmp - linkname), "%s", filename); 832 833 if (rm_rf(linkname)) 834 goto out_free; 835 836 err = 0; 837 out_free: 838 free(filename); 839 free(linkname); 840 return err; 841 } 842 843 static int filename__read_build_id_ns(const char *filename, 844 struct build_id *bid, 845 struct nsinfo *nsi) 846 { 847 struct nscookie nsc; 848 int ret; 849 850 nsinfo__mountns_enter(nsi, &nsc); 851 ret = filename__read_build_id(filename, bid, /*block=*/true); 852 nsinfo__mountns_exit(&nsc); 853 854 return ret; 855 } 856 857 static bool dso__build_id_mismatch(struct dso *dso, const char *name) 858 { 859 struct build_id bid = { .size = 0, }; 860 bool ret = false; 861 862 mutex_lock(dso__lock(dso)); 863 if (filename__read_build_id_ns(name, &bid, dso__nsinfo(dso)) >= 0) 864 ret = !dso__build_id_equal(dso, &bid); 865 866 mutex_unlock(dso__lock(dso)); 867 868 return ret; 869 } 870 871 static int dso__cache_build_id(struct dso *dso, struct machine *machine, 872 void *priv __maybe_unused) 873 { 874 bool is_kallsyms = dso__is_kallsyms(dso); 875 bool is_vdso = dso__is_vdso(dso); 876 const char *name = dso__long_name(dso); 877 const char *proper_name = NULL; 878 const char *root_dir = NULL; 879 char *allocated_name = NULL; 880 int ret = 0; 881 882 if (!dso__has_build_id(dso) || !dso__hit(dso)) 883 return 0; 884 885 if (dso__is_kcore(dso)) { 886 is_kallsyms = true; 887 name = machine->mmap_name; 888 } 889 890 if (!machine__is_host(machine)) { 891 if (*machine->root_dir) { 892 root_dir = machine->root_dir; 893 ret = asprintf(&allocated_name, "%s/%s", root_dir, name); 894 if (ret < 0) 895 return ret; 896 proper_name = name; 897 name = allocated_name; 898 } else if (is_kallsyms) { 899 /* Cannot get guest kallsyms */ 900 return 0; 901 } 902 } 903 904 if (!is_kallsyms && dso__build_id_mismatch(dso, name)) 905 goto out_free; 906 907 mutex_lock(dso__lock(dso)); 908 ret = build_id_cache__add_b(dso__bid(dso), name, dso__nsinfo(dso), 909 is_kallsyms, is_vdso, proper_name, root_dir); 910 mutex_unlock(dso__lock(dso)); 911 out_free: 912 free(allocated_name); 913 return ret; 914 } 915 916 static int 917 machines__for_each_dso(struct machines *machines, machine__dso_t fn, void *priv) 918 { 919 int ret = machine__for_each_dso(&machines->host, fn, priv); 920 struct rb_node *nd; 921 922 for (nd = rb_first_cached(&machines->guests); nd; 923 nd = rb_next(nd)) { 924 struct machine *pos = rb_entry(nd, struct machine, rb_node); 925 926 ret |= machine__for_each_dso(pos, fn, priv); 927 } 928 return ret ? -1 : 0; 929 } 930 931 int __perf_session__cache_build_ids(struct perf_session *session, 932 machine__dso_t fn, void *priv) 933 { 934 if (no_buildid_cache) 935 return 0; 936 937 if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST) 938 return -1; 939 940 return machines__for_each_dso(&session->machines, fn, priv) ? -1 : 0; 941 } 942 943 int perf_session__cache_build_ids(struct perf_session *session) 944 { 945 return __perf_session__cache_build_ids(session, dso__cache_build_id, NULL); 946 } 947 948 static bool machine__read_build_ids(struct machine *machine, bool with_hits) 949 { 950 return dsos__read_build_ids(&machine->dsos, with_hits); 951 } 952 953 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits) 954 { 955 struct rb_node *nd; 956 bool ret = machine__read_build_ids(&session->machines.host, with_hits); 957 958 for (nd = rb_first_cached(&session->machines.guests); nd; 959 nd = rb_next(nd)) { 960 struct machine *pos = rb_entry(nd, struct machine, rb_node); 961 ret |= machine__read_build_ids(pos, with_hits); 962 } 963 964 return ret; 965 } 966 967 void build_id__init(struct build_id *bid, const u8 *data, size_t size) 968 { 969 if (size > BUILD_ID_SIZE) { 970 pr_debug("Truncating build_id size from %zd\n", size); 971 size = BUILD_ID_SIZE; 972 } 973 memcpy(bid->data, data, size); 974 bid->size = size; 975 } 976 977 bool build_id__is_defined(const struct build_id *bid) 978 { 979 return bid && bid->size ? !!memchr_inv(bid->data, 0, bid->size) : false; 980 } 981