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 /* The caller is responsible to free the returned buffer. */
 180 char *build_id_cache__origname(const char *sbuild_id)
 181 {
 182         char *linkname;
 183         char buf[PATH_MAX];
 184         char *ret = NULL, *p;
 185         size_t offs = 5;        /* == strlen("../..") */
 186         ssize_t len;
 187
 188         linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 189         if (!linkname)
 190                 return NULL;
 191
 192         len = readlink(linkname, buf, sizeof(buf) - 1);
 193         if (len <= 0)
 194                 goto out;
 195         buf[len] = '\0';
 196
 197         /* The link should be "../..<origpath>/<sbuild_id>" */
 198         p = strrchr(buf, '/');  /* Cut off the "/<sbuild_id>" */
 199         if (p && (p > buf + offs)) {
 200                 *p = '\0';
 201                 if (buf[offs + 1] == '[')
 202                         offs++; /*
 203                                  * This is a DSO name, like [kernel.kallsyms].
 204                                  * Skip the first '/', since this is not the
 205                                  * cache of a regular file.
 206                                  */
 207                 ret = strdup(buf + offs);       /* Skip "../..[/]" */
 208         }
 209 out:
 210         free(linkname);
 211         return ret;
 212 }
 213
 214 /* Check if the given build_id cache is valid on current running system */
 215 static bool build_id_cache__valid_id(char *sbuild_id)
 216 {
 217         char real_sbuild_id[SBUILD_ID_SIZE] = "";
 218         char *pathname;
 219         int ret = 0;
 220         bool result = false;
 221
 222         pathname = build_id_cache__origname(sbuild_id);
 223         if (!pathname)
 224                 return false;
 225
 226         if (!strcmp(pathname, DSO__NAME_KALLSYMS))
 227                 ret = sysfs__sprintf_build_id("/", real_sbuild_id);
 228         else if (pathname[0] == '/')
 229                 ret = filename__sprintf_build_id(pathname, real_sbuild_id);
 230         else
 231                 ret = -EINVAL;  /* Should we support other special DSO cache? */
 232         if (ret >= 0)
 233                 result = (strcmp(sbuild_id, real_sbuild_id) == 0);
 234         free(pathname);
 235
 236         return result;
 237 }
 238
 239 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso)
 240 {
 241         return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : "elf");
 242 }
 243
 244 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
 245 {
 246         bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
 247         bool is_vdso = dso__is_vdso((struct dso *)dso);
 248         char sbuild_id[SBUILD_ID_SIZE];
 249         char *linkname;
 250         bool alloc = (bf == NULL);
 251         int ret;
 252
 253         if (!dso->has_build_id)
 254                 return NULL;
 255
 256         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 257         linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 258         if (!linkname)
 259                 return NULL;
 260
 261         /* Check if old style build_id cache */
 262         if (is_regular_file(linkname))
 263                 ret = asnprintf(&bf, size, "%s", linkname);
 264         else
 265                 ret = asnprintf(&bf, size, "%s/%s", linkname,
 266                          build_id_cache__basename(is_kallsyms, is_vdso));
 267         if (ret < 0 || (!alloc && size < (unsigned int)ret))
 268                 bf = NULL;
 269         free(linkname);
 270
 271         return bf;
 272 }
 273
 274 bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size)
 275 {
 276         char *id_name = NULL, *ch;
 277         struct stat sb;
 278         char sbuild_id[SBUILD_ID_SIZE];
 279
 280         if (!dso->has_build_id)
 281                 goto err;
 282
 283         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 284         id_name = build_id_cache__linkname(sbuild_id, NULL, 0);
 285         if (!id_name)
 286                 goto err;
 287         if (access(id_name, F_OK))
 288                 goto err;
 289         if (lstat(id_name, &sb) == -1)
 290                 goto err;
 291         if ((size_t)sb.st_size > size - 1)
 292                 goto err;
 293         if (readlink(id_name, bf, size - 1) < 0)
 294                 goto err;
 295
 296         bf[sb.st_size] = '\0';
 297
 298         /*
 299          * link should be:
 300          * ../../lib/modules/4.4.0-rc4/kernel/net/ipv4/netfilter/nf_nat_ipv4.ko/a09fe3eb3147dafa4e3b31dbd6257e4d696bdc92
 301          */
 302         ch = strrchr(bf, '/');
 303         if (!ch)
 304                 goto err;
 305         if (ch - 3 < bf)
 306                 goto err;
 307
 308         free(id_name);
 309         return strncmp(".ko", ch - 3, 3) == 0;
 310 err:
 311         pr_err("Invalid build id: %s\n", id_name ? :
 312                                          dso->long_name ? :
 313                                          dso->short_name ? :
 314                                          "[unknown]");
 315         free(id_name);
 316         return false;
 317 }
 318
 319 #define dsos__for_each_with_build_id(pos, head) \
 320         list_for_each_entry(pos, head, node)    \
 321                 if (!pos->has_build_id)         \
 322                         continue;               \
 323                 else
 324
 325 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 326                          pid_t pid, u16 misc, int fd)
 327 {
 328         int err;
 329         struct build_id_event b;
 330         size_t len;
 331
 332         len = name_len + 1;
 333         len = PERF_ALIGN(len, NAME_ALIGN);
 334
 335         memset(&b, 0, sizeof(b));
 336         memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
 337         b.pid = pid;
 338         b.header.misc = misc;
 339         b.header.size = sizeof(b) + len;
 340
 341         err = writen(fd, &b, sizeof(b));
 342         if (err < 0)
 343                 return err;
 344
 345         return write_padded(fd, name, name_len + 1, len);
 346 }
 347
 348 static int machine__write_buildid_table(struct machine *machine, int fd)
 349 {
 350         int err = 0;
 351         char nm[PATH_MAX];
 352         struct dso *pos;
 353         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 354             umisc = PERF_RECORD_MISC_USER;
 355
 356         if (!machine__is_host(machine)) {
 357                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 358                 umisc = PERF_RECORD_MISC_GUEST_USER;
 359         }
 360
 361         dsos__for_each_with_build_id(pos, &machine->dsos.head) {
 362                 const char *name;
 363                 size_t name_len;
 364                 bool in_kernel = false;
 365
 366                 if (!pos->hit && !dso__is_vdso(pos))
 367                         continue;
 368
 369                 if (dso__is_vdso(pos)) {
 370                         name = pos->short_name;
 371                         name_len = pos->short_name_len;
 372                 } else if (dso__is_kcore(pos)) {
 373                         machine__mmap_name(machine, nm, sizeof(nm));
 374                         name = nm;
 375                         name_len = strlen(nm);
 376                 } else {
 377                         name = pos->long_name;
 378                         name_len = pos->long_name_len;
 379                 }
 380
 381                 in_kernel = pos->kernel ||
 382                                 is_kernel_module(name,
 383                                         PERF_RECORD_MISC_CPUMODE_UNKNOWN);
 384                 err = write_buildid(name, name_len, pos->build_id, machine->pid,
 385                                     in_kernel ? kmisc : umisc, fd);
 386                 if (err)
 387                         break;
 388         }
 389
 390         return err;
 391 }
 392
 393 int perf_session__write_buildid_table(struct perf_session *session, int fd)
 394 {
 395         struct rb_node *nd;
 396         int err = machine__write_buildid_table(&session->machines.host, fd);
 397
 398         if (err)
 399                 return err;
 400
 401         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 402                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 403                 err = machine__write_buildid_table(pos, fd);
 404                 if (err)
 405                         break;
 406         }
 407         return err;
 408 }
 409
 410 static int __dsos__hit_all(struct list_head *head)
 411 {
 412         struct dso *pos;
 413
 414         list_for_each_entry(pos, head, node)
 415                 pos->hit = true;
 416
 417         return 0;
 418 }
 419
 420 static int machine__hit_all_dsos(struct machine *machine)
 421 {
 422         return __dsos__hit_all(&machine->dsos.head);
 423 }
 424
 425 int dsos__hit_all(struct perf_session *session)
 426 {
 427         struct rb_node *nd;
 428         int err;
 429
 430         err = machine__hit_all_dsos(&session->machines.host);
 431         if (err)
 432                 return err;
 433
 434         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 435                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 436
 437                 err = machine__hit_all_dsos(pos);
 438                 if (err)
 439                         return err;
 440         }
 441
 442         return 0;
 443 }
 444
 445 void disable_buildid_cache(void)
 446 {
 447         no_buildid_cache = true;
 448 }
 449
 450 static bool lsdir_bid_head_filter(const char *name __maybe_unused,
 451                                   struct dirent *d __maybe_unused)
 452 {
 453         return (strlen(d->d_name) == 2) &&
 454                 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
 455 }
 456
 457 static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
 458                                   struct dirent *d __maybe_unused)
 459 {
 460         int i = 0;
 461         while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
 462                 i++;
 463         return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
 464 }
 465
 466 struct strlist *build_id_cache__list_all(bool validonly)
 467 {
 468         struct strlist *toplist, *linklist = NULL, *bidlist;
 469         struct str_node *nd, *nd2;
 470         char *topdir, *linkdir = NULL;
 471         char sbuild_id[SBUILD_ID_SIZE];
 472
 473         /* for filename__ functions */
 474         if (validonly)
 475                 symbol__init(NULL);
 476
 477         /* Open the top-level directory */
 478         if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
 479                 return NULL;
 480
 481         bidlist = strlist__new(NULL, NULL);
 482         if (!bidlist)
 483                 goto out;
 484
 485         toplist = lsdir(topdir, lsdir_bid_head_filter);
 486         if (!toplist) {
 487                 pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
 488                 /* If there is no buildid cache, return an empty list */
 489                 if (errno == ENOENT)
 490                         goto out;
 491                 goto err_out;
 492         }
 493
 494         strlist__for_each_entry(nd, toplist) {
 495                 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
 496                         goto err_out;
 497                 /* Open the lower-level directory */
 498                 linklist = lsdir(linkdir, lsdir_bid_tail_filter);
 499                 if (!linklist) {
 500                         pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
 501                         goto err_out;
 502                 }
 503                 strlist__for_each_entry(nd2, linklist) {
 504                         if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
 505                                      nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
 506                                 goto err_out;
 507                         if (validonly && !build_id_cache__valid_id(sbuild_id))
 508                                 continue;
 509                         if (strlist__add(bidlist, sbuild_id) < 0)
 510                                 goto err_out;
 511                 }
 512                 strlist__delete(linklist);
 513                 zfree(&linkdir);
 514         }
 515
 516 out_free:
 517         strlist__delete(toplist);
 518 out:
 519         free(topdir);
 520
 521         return bidlist;
 522
 523 err_out:
 524         strlist__delete(linklist);
 525         zfree(&linkdir);
 526         strlist__delete(bidlist);
 527         bidlist = NULL;
 528         goto out_free;
 529 }
 530
 531 static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
 532 {
 533         size_t i;
 534
 535         for (i = 0; i < len; i++) {
 536                 if (!isxdigit(maybe_sbuild_id[i]))
 537                         return false;
 538         }
 539         return true;
 540 }
 541
 542 /* Return the valid complete build-id */
 543 char *build_id_cache__complement(const char *incomplete_sbuild_id)
 544 {
 545         struct strlist *bidlist;
 546         struct str_node *nd, *cand = NULL;
 547         char *sbuild_id = NULL;
 548         size_t len = strlen(incomplete_sbuild_id);
 549
 550         if (len >= SBUILD_ID_SIZE ||
 551             !str_is_build_id(incomplete_sbuild_id, len))
 552                 return NULL;
 553
 554         bidlist = build_id_cache__list_all(true);
 555         if (!bidlist)
 556                 return NULL;
 557
 558         strlist__for_each_entry(nd, bidlist) {
 559                 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
 560                         continue;
 561                 if (cand) {     /* Error: There are more than 2 candidates. */
 562                         cand = NULL;
 563                         break;
 564                 }
 565                 cand = nd;
 566         }
 567         if (cand)
 568                 sbuild_id = strdup(cand->s);
 569         strlist__delete(bidlist);
 570
 571         return sbuild_id;
 572 }
 573
 574 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
 575                                bool is_kallsyms, bool is_vdso)
 576 {
 577         char *realname = (char *)name, *filename;
 578         bool slash = is_kallsyms || is_vdso;
 579
 580         if (!slash) {
 581                 realname = realpath(name, NULL);
 582                 if (!realname)
 583                         return NULL;
 584         }
 585
 586         if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
 587                      is_vdso ? DSO__NAME_VDSO : realname,
 588                      sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
 589                 filename = NULL;
 590
 591         if (!slash)
 592                 free(realname);
 593
 594         return filename;
 595 }
 596
 597 int build_id_cache__list_build_ids(const char *pathname,
 598                                    struct strlist **result)
 599 {
 600         char *dir_name;
 601         int ret = 0;
 602
 603         dir_name = build_id_cache__cachedir(NULL, pathname, false, false);
 604         if (!dir_name)
 605                 return -ENOMEM;
 606
 607         *result = lsdir(dir_name, lsdir_no_dot_filter);
 608         if (!*result)
 609                 ret = -errno;
 610         free(dir_name);
 611
 612         return ret;
 613 }
 614
 615 #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
 616 static int build_id_cache__add_sdt_cache(const char *sbuild_id,
 617                                           const char *realname)
 618 {
 619         struct probe_cache *cache;
 620         int ret;
 621
 622         cache = probe_cache__new(sbuild_id);
 623         if (!cache)
 624                 return -1;
 625
 626         ret = probe_cache__scan_sdt(cache, realname);
 627         if (ret >= 0) {
 628                 pr_debug4("Found %d SDTs in %s\n", ret, realname);
 629                 if (probe_cache__commit(cache) < 0)
 630                         ret = -1;
 631         }
 632         probe_cache__delete(cache);
 633         return ret;
 634 }
 635 #else
 636 #define build_id_cache__add_sdt_cache(sbuild_id, realname) (0)
 637 #endif
 638
 639 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 640                           bool is_kallsyms, bool is_vdso)
 641 {
 642         const size_t size = PATH_MAX;
 643         char *realname = NULL, *filename = NULL, *dir_name = NULL,
 644              *linkname = zalloc(size), *tmp;
 645         int err = -1;
 646
 647         if (!is_kallsyms) {
 648                 realname = realpath(name, NULL);
 649                 if (!realname)
 650                         goto out_free;
 651         }
 652
 653         dir_name = build_id_cache__cachedir(sbuild_id, name,
 654                                             is_kallsyms, is_vdso);
 655         if (!dir_name)
 656                 goto out_free;
 657
 658         /* Remove old style build-id cache */
 659         if (is_regular_file(dir_name))
 660                 if (unlink(dir_name))
 661                         goto out_free;
 662
 663         if (mkdir_p(dir_name, 0755))
 664                 goto out_free;
 665
 666         /* Save the allocated buildid dirname */
 667         if (asprintf(&filename, "%s/%s", dir_name,
 668                      build_id_cache__basename(is_kallsyms, is_vdso)) < 0) {
 669                 filename = NULL;
 670                 goto out_free;
 671         }
 672
 673         if (access(filename, F_OK)) {
 674                 if (is_kallsyms) {
 675                          if (copyfile("/proc/kallsyms", filename))
 676                                 goto out_free;
 677                 } else if (link(realname, filename) && errno != EEXIST &&
 678                                 copyfile(name, filename))
 679                         goto out_free;
 680         }
 681
 682         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 683                 goto out_free;
 684         tmp = strrchr(linkname, '/');
 685         *tmp = '\0';
 686
 687         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 688                 goto out_free;
 689
 690         *tmp = '/';
 691         tmp = dir_name + strlen(buildid_dir) - 5;
 692         memcpy(tmp, "../..", 5);
 693
 694         if (symlink(tmp, linkname) == 0)
 695                 err = 0;
 696
 697         /* Update SDT cache : error is just warned */
 698         if (build_id_cache__add_sdt_cache(sbuild_id, realname) < 0)
 699                 pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
 700
 701 out_free:
 702         if (!is_kallsyms)
 703                 free(realname);
 704         free(filename);
 705         free(dir_name);
 706         free(linkname);
 707         return err;
 708 }
 709
 710 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 711                                  const char *name, bool is_kallsyms,
 712                                  bool is_vdso)
 713 {
 714         char sbuild_id[SBUILD_ID_SIZE];
 715
 716         build_id__sprintf(build_id, build_id_size, sbuild_id);
 717
 718         return build_id_cache__add_s(sbuild_id, name, is_kallsyms, is_vdso);
 719 }
 720
 721 bool build_id_cache__cached(const char *sbuild_id)
 722 {
 723         bool ret = false;
 724         char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
 725
 726         if (filename && !access(filename, F_OK))
 727                 ret = true;
 728         free(filename);
 729
 730         return ret;
 731 }
 732
 733 int build_id_cache__remove_s(const char *sbuild_id)
 734 {
 735         const size_t size = PATH_MAX;
 736         char *filename = zalloc(size),
 737              *linkname = zalloc(size), *tmp;
 738         int err = -1;
 739
 740         if (filename == NULL || linkname == NULL)
 741                 goto out_free;
 742
 743         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 744                 goto out_free;
 745
 746         if (access(linkname, F_OK))
 747                 goto out_free;
 748
 749         if (readlink(linkname, filename, size - 1) < 0)
 750                 goto out_free;
 751
 752         if (unlink(linkname))
 753                 goto out_free;
 754
 755         /*
 756          * Since the link is relative, we must make it absolute:
 757          */
 758         tmp = strrchr(linkname, '/') + 1;
 759         snprintf(tmp, size - (tmp - linkname), "%s", filename);
 760
 761         if (rm_rf(linkname))
 762                 goto out_free;
 763
 764         err = 0;
 765 out_free:
 766         free(filename);
 767         free(linkname);
 768         return err;
 769 }
 770
 771 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 772 {
 773         bool is_kallsyms = dso__is_kallsyms(dso);
 774         bool is_vdso = dso__is_vdso(dso);
 775         const char *name = dso->long_name;
 776         char nm[PATH_MAX];
 777
 778         if (dso__is_kcore(dso)) {
 779                 is_kallsyms = true;
 780                 machine__mmap_name(machine, nm, sizeof(nm));
 781                 name = nm;
 782         }
 783         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 784                                      is_kallsyms, is_vdso);
 785 }
 786
 787 static int __dsos__cache_build_ids(struct list_head *head,
 788                                    struct machine *machine)
 789 {
 790         struct dso *pos;
 791         int err = 0;
 792
 793         dsos__for_each_with_build_id(pos, head)
 794                 if (dso__cache_build_id(pos, machine))
 795                         err = -1;
 796
 797         return err;
 798 }
 799
 800 static int machine__cache_build_ids(struct machine *machine)
 801 {
 802         return __dsos__cache_build_ids(&machine->dsos.head, machine);
 803 }
 804
 805 int perf_session__cache_build_ids(struct perf_session *session)
 806 {
 807         struct rb_node *nd;
 808         int ret;
 809
 810         if (no_buildid_cache)
 811                 return 0;
 812
 813         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 814                 return -1;
 815
 816         ret = machine__cache_build_ids(&session->machines.host);
 817
 818         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 819                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 820                 ret |= machine__cache_build_ids(pos);
 821         }
 822         return ret ? -1 : 0;
 823 }
 824
 825 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 826 {
 827         return __dsos__read_build_ids(&machine->dsos.head, with_hits);
 828 }
 829
 830 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 831 {
 832         struct rb_node *nd;
 833         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 834
 835         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 836                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 837                 ret |= machine__read_build_ids(pos, with_hits);
 838         }
 839
 840         return ret;
 841 }