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 #define dsos__for_each_with_build_id(pos, head) \
 282         list_for_each_entry(pos, head, node)    \
 283                 if (!pos->has_build_id)         \
 284                         continue;               \
 285                 else
 286
 287 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 288                          pid_t pid, u16 misc, int fd)
 289 {
 290         int err;
 291         struct build_id_event b;
 292         size_t len;
 293
 294         len = name_len + 1;
 295         len = PERF_ALIGN(len, NAME_ALIGN);
 296
 297         memset(&b, 0, sizeof(b));
 298         memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
 299         b.pid = pid;
 300         b.header.misc = misc;
 301         b.header.size = sizeof(b) + len;
 302
 303         err = writen(fd, &b, sizeof(b));
 304         if (err < 0)
 305                 return err;
 306
 307         return write_padded(fd, name, name_len + 1, len);
 308 }
 309
 310 static int machine__write_buildid_table(struct machine *machine, int fd)
 311 {
 312         int err = 0;
 313         char nm[PATH_MAX];
 314         struct dso *pos;
 315         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 316             umisc = PERF_RECORD_MISC_USER;
 317
 318         if (!machine__is_host(machine)) {
 319                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 320                 umisc = PERF_RECORD_MISC_GUEST_USER;
 321         }
 322
 323         dsos__for_each_with_build_id(pos, &machine->dsos.head) {
 324                 const char *name;
 325                 size_t name_len;
 326                 bool in_kernel = false;
 327
 328                 if (!pos->hit && !dso__is_vdso(pos))
 329                         continue;
 330
 331                 if (dso__is_vdso(pos)) {
 332                         name = pos->short_name;
 333                         name_len = pos->short_name_len;
 334                 } else if (dso__is_kcore(pos)) {
 335                         machine__mmap_name(machine, nm, sizeof(nm));
 336                         name = nm;
 337                         name_len = strlen(nm);
 338                 } else {
 339                         name = pos->long_name;
 340                         name_len = pos->long_name_len;
 341                 }
 342
 343                 in_kernel = pos->kernel ||
 344                                 is_kernel_module(name,
 345                                         PERF_RECORD_MISC_CPUMODE_UNKNOWN);
 346                 err = write_buildid(name, name_len, pos->build_id, machine->pid,
 347                                     in_kernel ? kmisc : umisc, fd);
 348                 if (err)
 349                         break;
 350         }
 351
 352         return err;
 353 }
 354
 355 int perf_session__write_buildid_table(struct perf_session *session, int fd)
 356 {
 357         struct rb_node *nd;
 358         int err = machine__write_buildid_table(&session->machines.host, fd);
 359
 360         if (err)
 361                 return err;
 362
 363         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 364                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 365                 err = machine__write_buildid_table(pos, fd);
 366                 if (err)
 367                         break;
 368         }
 369         return err;
 370 }
 371
 372 static int __dsos__hit_all(struct list_head *head)
 373 {
 374         struct dso *pos;
 375
 376         list_for_each_entry(pos, head, node)
 377                 pos->hit = true;
 378
 379         return 0;
 380 }
 381
 382 static int machine__hit_all_dsos(struct machine *machine)
 383 {
 384         return __dsos__hit_all(&machine->dsos.head);
 385 }
 386
 387 int dsos__hit_all(struct perf_session *session)
 388 {
 389         struct rb_node *nd;
 390         int err;
 391
 392         err = machine__hit_all_dsos(&session->machines.host);
 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
 399                 err = machine__hit_all_dsos(pos);
 400                 if (err)
 401                         return err;
 402         }
 403
 404         return 0;
 405 }
 406
 407 void disable_buildid_cache(void)
 408 {
 409         no_buildid_cache = true;
 410 }
 411
 412 static bool lsdir_bid_head_filter(const char *name __maybe_unused,
 413                                   struct dirent *d)
 414 {
 415         return (strlen(d->d_name) == 2) &&
 416                 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
 417 }
 418
 419 static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
 420                                   struct dirent *d)
 421 {
 422         int i = 0;
 423         while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
 424                 i++;
 425         return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
 426 }
 427
 428 struct strlist *build_id_cache__list_all(bool validonly)
 429 {
 430         struct strlist *toplist, *linklist = NULL, *bidlist;
 431         struct str_node *nd, *nd2;
 432         char *topdir, *linkdir = NULL;
 433         char sbuild_id[SBUILD_ID_SIZE];
 434
 435         /* for filename__ functions */
 436         if (validonly)
 437                 symbol__init(NULL);
 438
 439         /* Open the top-level directory */
 440         if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
 441                 return NULL;
 442
 443         bidlist = strlist__new(NULL, NULL);
 444         if (!bidlist)
 445                 goto out;
 446
 447         toplist = lsdir(topdir, lsdir_bid_head_filter);
 448         if (!toplist) {
 449                 pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
 450                 /* If there is no buildid cache, return an empty list */
 451                 if (errno == ENOENT)
 452                         goto out;
 453                 goto err_out;
 454         }
 455
 456         strlist__for_each_entry(nd, toplist) {
 457                 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
 458                         goto err_out;
 459                 /* Open the lower-level directory */
 460                 linklist = lsdir(linkdir, lsdir_bid_tail_filter);
 461                 if (!linklist) {
 462                         pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
 463                         goto err_out;
 464                 }
 465                 strlist__for_each_entry(nd2, linklist) {
 466                         if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
 467                                      nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
 468                                 goto err_out;
 469                         if (validonly && !build_id_cache__valid_id(sbuild_id))
 470                                 continue;
 471                         if (strlist__add(bidlist, sbuild_id) < 0)
 472                                 goto err_out;
 473                 }
 474                 strlist__delete(linklist);
 475                 zfree(&linkdir);
 476         }
 477
 478 out_free:
 479         strlist__delete(toplist);
 480 out:
 481         free(topdir);
 482
 483         return bidlist;
 484
 485 err_out:
 486         strlist__delete(linklist);
 487         zfree(&linkdir);
 488         strlist__delete(bidlist);
 489         bidlist = NULL;
 490         goto out_free;
 491 }
 492
 493 static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
 494 {
 495         size_t i;
 496
 497         for (i = 0; i < len; i++) {
 498                 if (!isxdigit(maybe_sbuild_id[i]))
 499                         return false;
 500         }
 501         return true;
 502 }
 503
 504 /* Return the valid complete build-id */
 505 char *build_id_cache__complement(const char *incomplete_sbuild_id)
 506 {
 507         struct strlist *bidlist;
 508         struct str_node *nd, *cand = NULL;
 509         char *sbuild_id = NULL;
 510         size_t len = strlen(incomplete_sbuild_id);
 511
 512         if (len >= SBUILD_ID_SIZE ||
 513             !str_is_build_id(incomplete_sbuild_id, len))
 514                 return NULL;
 515
 516         bidlist = build_id_cache__list_all(true);
 517         if (!bidlist)
 518                 return NULL;
 519
 520         strlist__for_each_entry(nd, bidlist) {
 521                 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
 522                         continue;
 523                 if (cand) {     /* Error: There are more than 2 candidates. */
 524                         cand = NULL;
 525                         break;
 526                 }
 527                 cand = nd;
 528         }
 529         if (cand)
 530                 sbuild_id = strdup(cand->s);
 531         strlist__delete(bidlist);
 532
 533         return sbuild_id;
 534 }
 535
 536 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
 537                                bool is_kallsyms, bool is_vdso)
 538 {
 539         char *realname = (char *)name, *filename;
 540         bool slash = is_kallsyms || is_vdso;
 541
 542         if (!slash) {
 543                 realname = realpath(name, NULL);
 544                 if (!realname)
 545                         return NULL;
 546         }
 547
 548         if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
 549                      is_vdso ? DSO__NAME_VDSO : realname,
 550                      sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
 551                 filename = NULL;
 552
 553         if (!slash)
 554                 free(realname);
 555
 556         return filename;
 557 }
 558
 559 int build_id_cache__list_build_ids(const char *pathname,
 560                                    struct strlist **result)
 561 {
 562         char *dir_name;
 563         int ret = 0;
 564
 565         dir_name = build_id_cache__cachedir(NULL, pathname, false, false);
 566         if (!dir_name)
 567                 return -ENOMEM;
 568
 569         *result = lsdir(dir_name, lsdir_no_dot_filter);
 570         if (!*result)
 571                 ret = -errno;
 572         free(dir_name);
 573
 574         return ret;
 575 }
 576
 577 #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
 578 static int build_id_cache__add_sdt_cache(const char *sbuild_id,
 579                                           const char *realname)
 580 {
 581         struct probe_cache *cache;
 582         int ret;
 583
 584         cache = probe_cache__new(sbuild_id);
 585         if (!cache)
 586                 return -1;
 587
 588         ret = probe_cache__scan_sdt(cache, realname);
 589         if (ret >= 0) {
 590                 pr_debug4("Found %d SDTs in %s\n", ret, realname);
 591                 if (probe_cache__commit(cache) < 0)
 592                         ret = -1;
 593         }
 594         probe_cache__delete(cache);
 595         return ret;
 596 }
 597 #else
 598 #define build_id_cache__add_sdt_cache(sbuild_id, realname) (0)
 599 #endif
 600
 601 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 602                           bool is_kallsyms, bool is_vdso)
 603 {
 604         const size_t size = PATH_MAX;
 605         char *realname = NULL, *filename = NULL, *dir_name = NULL,
 606              *linkname = zalloc(size), *tmp;
 607         int err = -1;
 608
 609         if (!is_kallsyms) {
 610                 realname = realpath(name, NULL);
 611                 if (!realname)
 612                         goto out_free;
 613         }
 614
 615         dir_name = build_id_cache__cachedir(sbuild_id, name,
 616                                             is_kallsyms, is_vdso);
 617         if (!dir_name)
 618                 goto out_free;
 619
 620         /* Remove old style build-id cache */
 621         if (is_regular_file(dir_name))
 622                 if (unlink(dir_name))
 623                         goto out_free;
 624
 625         if (mkdir_p(dir_name, 0755))
 626                 goto out_free;
 627
 628         /* Save the allocated buildid dirname */
 629         if (asprintf(&filename, "%s/%s", dir_name,
 630                      build_id_cache__basename(is_kallsyms, is_vdso)) < 0) {
 631                 filename = NULL;
 632                 goto out_free;
 633         }
 634
 635         if (access(filename, F_OK)) {
 636                 if (is_kallsyms) {
 637                          if (copyfile("/proc/kallsyms", filename))
 638                                 goto out_free;
 639                 } else if (link(realname, filename) && errno != EEXIST &&
 640                                 copyfile(name, filename))
 641                         goto out_free;
 642         }
 643
 644         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 645                 goto out_free;
 646         tmp = strrchr(linkname, '/');
 647         *tmp = '\0';
 648
 649         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 650                 goto out_free;
 651
 652         *tmp = '/';
 653         tmp = dir_name + strlen(buildid_dir) - 5;
 654         memcpy(tmp, "../..", 5);
 655
 656         if (symlink(tmp, linkname) == 0)
 657                 err = 0;
 658
 659         /* Update SDT cache : error is just warned */
 660         if (realname && build_id_cache__add_sdt_cache(sbuild_id, realname) < 0)
 661                 pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
 662
 663 out_free:
 664         if (!is_kallsyms)
 665                 free(realname);
 666         free(filename);
 667         free(dir_name);
 668         free(linkname);
 669         return err;
 670 }
 671
 672 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 673                                  const char *name, bool is_kallsyms,
 674                                  bool is_vdso)
 675 {
 676         char sbuild_id[SBUILD_ID_SIZE];
 677
 678         build_id__sprintf(build_id, build_id_size, sbuild_id);
 679
 680         return build_id_cache__add_s(sbuild_id, name, is_kallsyms, is_vdso);
 681 }
 682
 683 bool build_id_cache__cached(const char *sbuild_id)
 684 {
 685         bool ret = false;
 686         char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
 687
 688         if (filename && !access(filename, F_OK))
 689                 ret = true;
 690         free(filename);
 691
 692         return ret;
 693 }
 694
 695 int build_id_cache__remove_s(const char *sbuild_id)
 696 {
 697         const size_t size = PATH_MAX;
 698         char *filename = zalloc(size),
 699              *linkname = zalloc(size), *tmp;
 700         int err = -1;
 701
 702         if (filename == NULL || linkname == NULL)
 703                 goto out_free;
 704
 705         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 706                 goto out_free;
 707
 708         if (access(linkname, F_OK))
 709                 goto out_free;
 710
 711         if (readlink(linkname, filename, size - 1) < 0)
 712                 goto out_free;
 713
 714         if (unlink(linkname))
 715                 goto out_free;
 716
 717         /*
 718          * Since the link is relative, we must make it absolute:
 719          */
 720         tmp = strrchr(linkname, '/') + 1;
 721         snprintf(tmp, size - (tmp - linkname), "%s", filename);
 722
 723         if (rm_rf(linkname))
 724                 goto out_free;
 725
 726         err = 0;
 727 out_free:
 728         free(filename);
 729         free(linkname);
 730         return err;
 731 }
 732
 733 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 734 {
 735         bool is_kallsyms = dso__is_kallsyms(dso);
 736         bool is_vdso = dso__is_vdso(dso);
 737         const char *name = dso->long_name;
 738         char nm[PATH_MAX];
 739
 740         if (dso__is_kcore(dso)) {
 741                 is_kallsyms = true;
 742                 machine__mmap_name(machine, nm, sizeof(nm));
 743                 name = nm;
 744         }
 745         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 746                                      is_kallsyms, is_vdso);
 747 }
 748
 749 static int __dsos__cache_build_ids(struct list_head *head,
 750                                    struct machine *machine)
 751 {
 752         struct dso *pos;
 753         int err = 0;
 754
 755         dsos__for_each_with_build_id(pos, head)
 756                 if (dso__cache_build_id(pos, machine))
 757                         err = -1;
 758
 759         return err;
 760 }
 761
 762 static int machine__cache_build_ids(struct machine *machine)
 763 {
 764         return __dsos__cache_build_ids(&machine->dsos.head, machine);
 765 }
 766
 767 int perf_session__cache_build_ids(struct perf_session *session)
 768 {
 769         struct rb_node *nd;
 770         int ret;
 771
 772         if (no_buildid_cache)
 773                 return 0;
 774
 775         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 776                 return -1;
 777
 778         ret = machine__cache_build_ids(&session->machines.host);
 779
 780         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 781                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 782                 ret |= machine__cache_build_ids(pos);
 783         }
 784         return ret ? -1 : 0;
 785 }
 786
 787 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 788 {
 789         return __dsos__read_build_ids(&machine->dsos.head, with_hits);
 790 }
 791
 792 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 793 {
 794         struct rb_node *nd;
 795         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 796
 797         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 798                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 799                 ret |= machine__read_build_ids(pos, with_hits);
 800         }
 801
 802         return ret;
 803 }