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