tools/perf/util/build-id.c

   1 /*
   2  * build-id.c
   3  *
   4  * build-id support
   5  *
   6  * Copyright (C) 2009, 2010 Red Hat Inc.
   7  * Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
   8  */
   9 #include "util.h"
  10 #include <dirent.h>
  11 #include <errno.h>
  12 #include <stdio.h>
  13 #include <sys/stat.h>
  14 #include <sys/types.h>
  15 #include "build-id.h"
  16 #include "event.h"
  17 #include "symbol.h"
  18 #include "thread.h"
  19 #include <linux/kernel.h>
  20 #include "debug.h"
  21 #include "session.h"
  22 #include "tool.h"
  23 #include "header.h"
  24 #include "vdso.h"
  25 #include "path.h"
  26 #include "probe-file.h"
  27 #include "strlist.h"
  28
  29 #include "sane_ctype.h"
  30
  31 static bool no_buildid_cache;
  32
  33 int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
  34                            union perf_event *event,
  35                            struct perf_sample *sample,
  36                            struct perf_evsel *evsel __maybe_unused,
  37                            struct machine *machine)
  38 {
  39         struct addr_location al;
  40         struct thread *thread = machine__findnew_thread(machine, sample->pid,
  41                                                         sample->tid);
  42
  43         if (thread == NULL) {
  44                 pr_err("problem processing %d event, skipping it.\n",
  45                         event->header.type);
  46                 return -1;
  47         }
  48
  49         thread__find_addr_map(thread, sample->cpumode, MAP__FUNCTION, sample->ip, &al);
  50
  51         if (al.map != NULL)
  52                 al.map->dso->hit = 1;
  53
  54         thread__put(thread);
  55         return 0;
  56 }
  57
  58 static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
  59                                        union perf_event *event,
  60                                        struct perf_sample *sample
  61                                        __maybe_unused,
  62                                        struct machine *machine)
  63 {
  64         struct thread *thread = machine__findnew_thread(machine,
  65                                                         event->fork.pid,
  66                                                         event->fork.tid);
  67
  68         dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
  69                     event->fork.ppid, event->fork.ptid);
  70
  71         if (thread) {
  72                 machine__remove_thread(machine, thread);
  73                 thread__put(thread);
  74         }
  75
  76         return 0;
  77 }
  78
  79 struct perf_tool build_id__mark_dso_hit_ops = {
  80         .sample = build_id__mark_dso_hit,
  81         .mmap   = perf_event__process_mmap,
  82         .mmap2  = perf_event__process_mmap2,
  83         .fork   = perf_event__process_fork,
  84         .exit   = perf_event__exit_del_thread,
  85         .attr            = perf_event__process_attr,
  86         .build_id        = perf_event__process_build_id,
  87         .ordered_events  = true,
  88 };
  89
  90 int build_id__sprintf(const u8 *build_id, int len, char *bf)
  91 {
  92         char *bid = bf;
  93         const u8 *raw = build_id;
  94         int i;
  95
  96         for (i = 0; i < len; ++i) {
  97                 sprintf(bid, "%02x", *raw);
  98                 ++raw;
  99                 bid += 2;
 100         }
 101
 102         return (bid - bf) + 1;
 103 }
 104
 105 int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
 106 {
 107         char notes[PATH_MAX];
 108         u8 build_id[BUILD_ID_SIZE];
 109         int ret;
 110
 111         if (!root_dir)
 112                 root_dir = "";
 113
 114         scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
 115
 116         ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
 117         if (ret < 0)
 118                 return ret;
 119
 120         return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
 121 }
 122
 123 int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
 124 {
 125         u8 build_id[BUILD_ID_SIZE];
 126         int ret;
 127
 128         ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
 129         if (ret < 0)
 130                 return ret;
 131         else if (ret != sizeof(build_id))
 132                 return -EINVAL;
 133
 134         return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
 135 }
 136
 137 /* asnprintf consolidates asprintf and snprintf */
 138 static int asnprintf(char **strp, size_t size, const char *fmt, ...)
 139 {
 140         va_list ap;
 141         int ret;
 142
 143         if (!strp)
 144                 return -EINVAL;
 145
 146         va_start(ap, fmt);
 147         if (*strp)
 148                 ret = vsnprintf(*strp, size, fmt, ap);
 149         else
 150                 ret = vasprintf(strp, fmt, ap);
 151         va_end(ap);
 152
 153         return ret;
 154 }
 155
 156 char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
 157                                     size_t size)
 158 {
 159         bool retry_old = true;
 160
 161         snprintf(bf, size, "%s/%s/%s/kallsyms",
 162                  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 163 retry:
 164         if (!access(bf, F_OK))
 165                 return bf;
 166         if (retry_old) {
 167                 /* Try old style kallsyms cache */
 168                 snprintf(bf, size, "%s/%s/%s",
 169                          buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 170                 retry_old = false;
 171                 goto retry;
 172         }
 173
 174         return NULL;
 175 }
 176
 177 char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size)
 178 {
 179         char *tmp = bf;
 180         int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
 181                             sbuild_id, sbuild_id + 2);
 182         if (ret < 0 || (tmp && size < (unsigned int)ret))
 183                 return NULL;
 184         return bf;
 185 }
 186
 187 char *build_id_cache__origname(const char *sbuild_id)
 188 {
 189         char *linkname;
 190         char buf[PATH_MAX];
 191         char *ret = NULL, *p;
 192         size_t offs = 5;        /* == strlen("../..") */
 193         ssize_t len;
 194
 195         linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 196         if (!linkname)
 197                 return NULL;
 198
 199         len = readlink(linkname, buf, sizeof(buf) - 1);
 200         if (len <= 0)
 201                 goto out;
 202         buf[len] = '\0';
 203
 204         /* The link should be "../..<origpath>/<sbuild_id>" */
 205         p = strrchr(buf, '/');  /* Cut off the "/<sbuild_id>" */
 206         if (p && (p > buf + offs)) {
 207                 *p = '\0';
 208                 if (buf[offs + 1] == '[')
 209                         offs++; /*
 210                                  * This is a DSO name, like [kernel.kallsyms].
 211                                  * Skip the first '/', since this is not the
 212                                  * cache of a regular file.
 213                                  */
 214                 ret = strdup(buf + offs);       /* Skip "../..[/]" */
 215         }
 216 out:
 217         free(linkname);
 218         return ret;
 219 }
 220
 221 /* Check if the given build_id cache is valid on current running system */
 222 static bool build_id_cache__valid_id(char *sbuild_id)
 223 {
 224         char real_sbuild_id[SBUILD_ID_SIZE] = "";
 225         char *pathname;
 226         int ret = 0;
 227         bool result = false;
 228
 229         pathname = build_id_cache__origname(sbuild_id);
 230         if (!pathname)
 231                 return false;
 232
 233         if (!strcmp(pathname, DSO__NAME_KALLSYMS))
 234                 ret = sysfs__sprintf_build_id("/", real_sbuild_id);
 235         else if (pathname[0] == '/')
 236                 ret = filename__sprintf_build_id(pathname, real_sbuild_id);
 237         else
 238                 ret = -EINVAL;  /* Should we support other special DSO cache? */
 239         if (ret >= 0)
 240                 result = (strcmp(sbuild_id, real_sbuild_id) == 0);
 241         free(pathname);
 242
 243         return result;
 244 }
 245
 246 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso)
 247 {
 248         return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : "elf");
 249 }
 250
 251 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
 252 {
 253         bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
 254         bool is_vdso = dso__is_vdso((struct dso *)dso);
 255         char sbuild_id[SBUILD_ID_SIZE];
 256         char *linkname;
 257         bool alloc = (bf == NULL);
 258         int ret;
 259
 260         if (!dso->has_build_id)
 261                 return NULL;
 262
 263         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 264         linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 265         if (!linkname)
 266                 return NULL;
 267
 268         /* Check if old style build_id cache */
 269         if (is_regular_file(linkname))
 270                 ret = asnprintf(&bf, size, "%s", linkname);
 271         else
 272                 ret = asnprintf(&bf, size, "%s/%s", linkname,
 273                          build_id_cache__basename(is_kallsyms, is_vdso));
 274         if (ret < 0 || (!alloc && size < (unsigned int)ret))
 275                 bf = NULL;
 276         free(linkname);
 277
 278         return bf;
 279 }
 280
 281 bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size)
 282 {
 283         char *id_name = NULL, *ch;
 284         struct stat sb;
 285         char sbuild_id[SBUILD_ID_SIZE];
 286
 287         if (!dso->has_build_id)
 288                 goto err;
 289
 290         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 291         id_name = build_id_cache__linkname(sbuild_id, NULL, 0);
 292         if (!id_name)
 293                 goto err;
 294         if (access(id_name, F_OK))
 295                 goto err;
 296         if (lstat(id_name, &sb) == -1)
 297                 goto err;
 298         if ((size_t)sb.st_size > size - 1)
 299                 goto err;
 300         if (readlink(id_name, bf, size - 1) < 0)
 301                 goto err;
 302
 303         bf[sb.st_size] = '\0';
 304
 305         /*
 306          * link should be:
 307          * ../../lib/modules/4.4.0-rc4/kernel/net/ipv4/netfilter/nf_nat_ipv4.ko/a09fe3eb3147dafa4e3b31dbd6257e4d696bdc92
 308          */
 309         ch = strrchr(bf, '/');
 310         if (!ch)
 311                 goto err;
 312         if (ch - 3 < bf)
 313                 goto err;
 314
 315         free(id_name);
 316         return strncmp(".ko", ch - 3, 3) == 0;
 317 err:
 318         pr_err("Invalid build id: %s\n", id_name ? :
 319                                          dso->long_name ? :
 320                                          dso->short_name ? :
 321                                          "[unknown]");
 322         free(id_name);
 323         return false;
 324 }
 325
 326 #define dsos__for_each_with_build_id(pos, head) \
 327         list_for_each_entry(pos, head, node)    \
 328                 if (!pos->has_build_id)         \
 329                         continue;               \
 330                 else
 331
 332 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 333                          pid_t pid, u16 misc, int fd)
 334 {
 335         int err;
 336         struct build_id_event b;
 337         size_t len;
 338
 339         len = name_len + 1;
 340         len = PERF_ALIGN(len, NAME_ALIGN);
 341
 342         memset(&b, 0, sizeof(b));
 343         memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
 344         b.pid = pid;
 345         b.header.misc = misc;
 346         b.header.size = sizeof(b) + len;
 347
 348         err = writen(fd, &b, sizeof(b));
 349         if (err < 0)
 350                 return err;
 351
 352         return write_padded(fd, name, name_len + 1, len);
 353 }
 354
 355 static int machine__write_buildid_table(struct machine *machine, int fd)
 356 {
 357         int err = 0;
 358         char nm[PATH_MAX];
 359         struct dso *pos;
 360         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 361             umisc = PERF_RECORD_MISC_USER;
 362
 363         if (!machine__is_host(machine)) {
 364                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 365                 umisc = PERF_RECORD_MISC_GUEST_USER;
 366         }
 367
 368         dsos__for_each_with_build_id(pos, &machine->dsos.head) {
 369                 const char *name;
 370                 size_t name_len;
 371                 bool in_kernel = false;
 372
 373                 if (!pos->hit && !dso__is_vdso(pos))
 374                         continue;
 375
 376                 if (dso__is_vdso(pos)) {
 377                         name = pos->short_name;
 378                         name_len = pos->short_name_len;
 379                 } else if (dso__is_kcore(pos)) {
 380                         machine__mmap_name(machine, nm, sizeof(nm));
 381                         name = nm;
 382                         name_len = strlen(nm);
 383                 } else {
 384                         name = pos->long_name;
 385                         name_len = pos->long_name_len;
 386                 }
 387
 388                 in_kernel = pos->kernel ||
 389                                 is_kernel_module(name,
 390                                         PERF_RECORD_MISC_CPUMODE_UNKNOWN);
 391                 err = write_buildid(name, name_len, pos->build_id, machine->pid,
 392                                     in_kernel ? kmisc : umisc, fd);
 393                 if (err)
 394                         break;
 395         }
 396
 397         return err;
 398 }
 399
 400 int perf_session__write_buildid_table(struct perf_session *session, int fd)
 401 {
 402         struct rb_node *nd;
 403         int err = machine__write_buildid_table(&session->machines.host, fd);
 404
 405         if (err)
 406                 return err;
 407
 408         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 409                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 410                 err = machine__write_buildid_table(pos, fd);
 411                 if (err)
 412                         break;
 413         }
 414         return err;
 415 }
 416
 417 static int __dsos__hit_all(struct list_head *head)
 418 {
 419         struct dso *pos;
 420
 421         list_for_each_entry(pos, head, node)
 422                 pos->hit = true;
 423
 424         return 0;
 425 }
 426
 427 static int machine__hit_all_dsos(struct machine *machine)
 428 {
 429         return __dsos__hit_all(&machine->dsos.head);
 430 }
 431
 432 int dsos__hit_all(struct perf_session *session)
 433 {
 434         struct rb_node *nd;
 435         int err;
 436
 437         err = machine__hit_all_dsos(&session->machines.host);
 438         if (err)
 439                 return err;
 440
 441         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 442                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 443
 444                 err = machine__hit_all_dsos(pos);
 445                 if (err)
 446                         return err;
 447         }
 448
 449         return 0;
 450 }
 451
 452 void disable_buildid_cache(void)
 453 {
 454         no_buildid_cache = true;
 455 }
 456
 457 static bool lsdir_bid_head_filter(const char *name __maybe_unused,
 458                                   struct dirent *d)
 459 {
 460         return (strlen(d->d_name) == 2) &&
 461                 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
 462 }
 463
 464 static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
 465                                   struct dirent *d)
 466 {
 467         int i = 0;
 468         while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
 469                 i++;
 470         return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
 471 }
 472
 473 struct strlist *build_id_cache__list_all(bool validonly)
 474 {
 475         struct strlist *toplist, *linklist = NULL, *bidlist;
 476         struct str_node *nd, *nd2;
 477         char *topdir, *linkdir = NULL;
 478         char sbuild_id[SBUILD_ID_SIZE];
 479
 480         /* for filename__ functions */
 481         if (validonly)
 482                 symbol__init(NULL);
 483
 484         /* Open the top-level directory */
 485         if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
 486                 return NULL;
 487
 488         bidlist = strlist__new(NULL, NULL);
 489         if (!bidlist)
 490                 goto out;
 491
 492         toplist = lsdir(topdir, lsdir_bid_head_filter);
 493         if (!toplist) {
 494                 pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
 495                 /* If there is no buildid cache, return an empty list */
 496                 if (errno == ENOENT)
 497                         goto out;
 498                 goto err_out;
 499         }
 500
 501         strlist__for_each_entry(nd, toplist) {
 502                 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
 503                         goto err_out;
 504                 /* Open the lower-level directory */
 505                 linklist = lsdir(linkdir, lsdir_bid_tail_filter);
 506                 if (!linklist) {
 507                         pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
 508                         goto err_out;
 509                 }
 510                 strlist__for_each_entry(nd2, linklist) {
 511                         if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
 512                                      nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
 513                                 goto err_out;
 514                         if (validonly && !build_id_cache__valid_id(sbuild_id))
 515                                 continue;
 516                         if (strlist__add(bidlist, sbuild_id) < 0)
 517                                 goto err_out;
 518                 }
 519                 strlist__delete(linklist);
 520                 zfree(&linkdir);
 521         }
 522
 523 out_free:
 524         strlist__delete(toplist);
 525 out:
 526         free(topdir);
 527
 528         return bidlist;
 529
 530 err_out:
 531         strlist__delete(linklist);
 532         zfree(&linkdir);
 533         strlist__delete(bidlist);
 534         bidlist = NULL;
 535         goto out_free;
 536 }
 537
 538 static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
 539 {
 540         size_t i;
 541
 542         for (i = 0; i < len; i++) {
 543                 if (!isxdigit(maybe_sbuild_id[i]))
 544                         return false;
 545         }
 546         return true;
 547 }
 548
 549 /* Return the valid complete build-id */
 550 char *build_id_cache__complement(const char *incomplete_sbuild_id)
 551 {
 552         struct strlist *bidlist;
 553         struct str_node *nd, *cand = NULL;
 554         char *sbuild_id = NULL;
 555         size_t len = strlen(incomplete_sbuild_id);
 556
 557         if (len >= SBUILD_ID_SIZE ||
 558             !str_is_build_id(incomplete_sbuild_id, len))
 559                 return NULL;
 560
 561         bidlist = build_id_cache__list_all(true);
 562         if (!bidlist)
 563                 return NULL;
 564
 565         strlist__for_each_entry(nd, bidlist) {
 566                 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
 567                         continue;
 568                 if (cand) {     /* Error: There are more than 2 candidates. */
 569                         cand = NULL;
 570                         break;
 571                 }
 572                 cand = nd;
 573         }
 574         if (cand)
 575                 sbuild_id = strdup(cand->s);
 576         strlist__delete(bidlist);
 577
 578         return sbuild_id;
 579 }
 580
 581 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
 582                                bool is_kallsyms, bool is_vdso)
 583 {
 584         char *realname = (char *)name, *filename;
 585         bool slash = is_kallsyms || is_vdso;
 586
 587         if (!slash) {
 588                 realname = realpath(name, NULL);
 589                 if (!realname)
 590                         return NULL;
 591         }
 592
 593         if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
 594                      is_vdso ? DSO__NAME_VDSO : realname,
 595                      sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
 596                 filename = NULL;
 597
 598         if (!slash)
 599                 free(realname);
 600
 601         return filename;
 602 }
 603
 604 int build_id_cache__list_build_ids(const char *pathname,
 605                                    struct strlist **result)
 606 {
 607         char *dir_name;
 608         int ret = 0;
 609
 610         dir_name = build_id_cache__cachedir(NULL, pathname, false, false);
 611         if (!dir_name)
 612                 return -ENOMEM;
 613
 614         *result = lsdir(dir_name, lsdir_no_dot_filter);
 615         if (!*result)
 616                 ret = -errno;
 617         free(dir_name);
 618
 619         return ret;
 620 }
 621
 622 #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
 623 static int build_id_cache__add_sdt_cache(const char *sbuild_id,
 624                                           const char *realname)
 625 {
 626         struct probe_cache *cache;
 627         int ret;
 628
 629         cache = probe_cache__new(sbuild_id);
 630         if (!cache)
 631                 return -1;
 632
 633         ret = probe_cache__scan_sdt(cache, realname);
 634         if (ret >= 0) {
 635                 pr_debug4("Found %d SDTs in %s\n", ret, realname);
 636                 if (probe_cache__commit(cache) < 0)
 637                         ret = -1;
 638         }
 639         probe_cache__delete(cache);
 640         return ret;
 641 }
 642 #else
 643 #define build_id_cache__add_sdt_cache(sbuild_id, realname) (0)
 644 #endif
 645
 646 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 647                           bool is_kallsyms, bool is_vdso)
 648 {
 649         const size_t size = PATH_MAX;
 650         char *realname = NULL, *filename = NULL, *dir_name = NULL,
 651              *linkname = zalloc(size), *tmp;
 652         int err = -1;
 653
 654         if (!is_kallsyms) {
 655                 realname = realpath(name, NULL);
 656                 if (!realname)
 657                         goto out_free;
 658         }
 659
 660         dir_name = build_id_cache__cachedir(sbuild_id, name,
 661                                             is_kallsyms, is_vdso);
 662         if (!dir_name)
 663                 goto out_free;
 664
 665         /* Remove old style build-id cache */
 666         if (is_regular_file(dir_name))
 667                 if (unlink(dir_name))
 668                         goto out_free;
 669
 670         if (mkdir_p(dir_name, 0755))
 671                 goto out_free;
 672
 673         /* Save the allocated buildid dirname */
 674         if (asprintf(&filename, "%s/%s", dir_name,
 675                      build_id_cache__basename(is_kallsyms, is_vdso)) < 0) {
 676                 filename = NULL;
 677                 goto out_free;
 678         }
 679
 680         if (access(filename, F_OK)) {
 681                 if (is_kallsyms) {
 682                          if (copyfile("/proc/kallsyms", filename))
 683                                 goto out_free;
 684                 } else if (link(realname, filename) && errno != EEXIST &&
 685                                 copyfile(name, filename))
 686                         goto out_free;
 687         }
 688
 689         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 690                 goto out_free;
 691         tmp = strrchr(linkname, '/');
 692         *tmp = '\0';
 693
 694         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 695                 goto out_free;
 696
 697         *tmp = '/';
 698         tmp = dir_name + strlen(buildid_dir) - 5;
 699         memcpy(tmp, "../..", 5);
 700
 701         if (symlink(tmp, linkname) == 0)
 702                 err = 0;
 703
 704         /* Update SDT cache : error is just warned */
 705         if (realname && build_id_cache__add_sdt_cache(sbuild_id, realname) < 0)
 706                 pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
 707
 708 out_free:
 709         if (!is_kallsyms)
 710                 free(realname);
 711         free(filename);
 712         free(dir_name);
 713         free(linkname);
 714         return err;
 715 }
 716
 717 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 718                                  const char *name, bool is_kallsyms,
 719                                  bool is_vdso)
 720 {
 721         char sbuild_id[SBUILD_ID_SIZE];
 722
 723         build_id__sprintf(build_id, build_id_size, sbuild_id);
 724
 725         return build_id_cache__add_s(sbuild_id, name, is_kallsyms, is_vdso);
 726 }
 727
 728 bool build_id_cache__cached(const char *sbuild_id)
 729 {
 730         bool ret = false;
 731         char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
 732
 733         if (filename && !access(filename, F_OK))
 734                 ret = true;
 735         free(filename);
 736
 737         return ret;
 738 }
 739
 740 int build_id_cache__remove_s(const char *sbuild_id)
 741 {
 742         const size_t size = PATH_MAX;
 743         char *filename = zalloc(size),
 744              *linkname = zalloc(size), *tmp;
 745         int err = -1;
 746
 747         if (filename == NULL || linkname == NULL)
 748                 goto out_free;
 749
 750         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 751                 goto out_free;
 752
 753         if (access(linkname, F_OK))
 754                 goto out_free;
 755
 756         if (readlink(linkname, filename, size - 1) < 0)
 757                 goto out_free;
 758
 759         if (unlink(linkname))
 760                 goto out_free;
 761
 762         /*
 763          * Since the link is relative, we must make it absolute:
 764          */
 765         tmp = strrchr(linkname, '/') + 1;
 766         snprintf(tmp, size - (tmp - linkname), "%s", filename);
 767
 768         if (rm_rf(linkname))
 769                 goto out_free;
 770
 771         err = 0;
 772 out_free:
 773         free(filename);
 774         free(linkname);
 775         return err;
 776 }
 777
 778 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 779 {
 780         bool is_kallsyms = dso__is_kallsyms(dso);
 781         bool is_vdso = dso__is_vdso(dso);
 782         const char *name = dso->long_name;
 783         char nm[PATH_MAX];
 784
 785         if (dso__is_kcore(dso)) {
 786                 is_kallsyms = true;
 787                 machine__mmap_name(machine, nm, sizeof(nm));
 788                 name = nm;
 789         }
 790         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 791                                      is_kallsyms, is_vdso);
 792 }
 793
 794 static int __dsos__cache_build_ids(struct list_head *head,
 795                                    struct machine *machine)
 796 {
 797         struct dso *pos;
 798         int err = 0;
 799
 800         dsos__for_each_with_build_id(pos, head)
 801                 if (dso__cache_build_id(pos, machine))
 802                         err = -1;
 803
 804         return err;
 805 }
 806
 807 static int machine__cache_build_ids(struct machine *machine)
 808 {
 809         return __dsos__cache_build_ids(&machine->dsos.head, machine);
 810 }
 811
 812 int perf_session__cache_build_ids(struct perf_session *session)
 813 {
 814         struct rb_node *nd;
 815         int ret;
 816
 817         if (no_buildid_cache)
 818                 return 0;
 819
 820         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 821                 return -1;
 822
 823         ret = machine__cache_build_ids(&session->machines.host);
 824
 825         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 826                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 827                 ret |= machine__cache_build_ids(pos);
 828         }
 829         return ret ? -1 : 0;
 830 }
 831
 832 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 833 {
 834         return __dsos__read_build_ids(&machine->dsos.head, with_hits);
 835 }
 836
 837 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 838 {
 839         struct rb_node *nd;
 840         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 841
 842         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 843                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 844                 ret |= machine__read_build_ids(pos, with_hits);
 845         }
 846
 847         return ret;
 848 }