tools/perf/util/build-id.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * build-id.c
   4  *
   5  * build-id support
   6  *
   7  * Copyright (C) 2009, 2010 Red Hat Inc.
   8  * Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
   9  */
  10 #include "util.h"
  11 #include <dirent.h>
  12 #include <errno.h>
  13 #include <stdio.h>
  14 #include <sys/stat.h>
  15 #include <sys/types.h>
  16 #include "build-id.h"
  17 #include "event.h"
  18 #include "symbol.h"
  19 #include "thread.h"
  20 #include <linux/kernel.h>
  21 #include "debug.h"
  22 #include "session.h"
  23 #include "tool.h"
  24 #include "header.h"
  25 #include "vdso.h"
  26 #include "path.h"
  27 #include "probe-file.h"
  28 #include "strlist.h"
  29
  30 #include "sane_ctype.h"
  31
  32 static bool no_buildid_cache;
  33
  34 int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
  35                            union perf_event *event,
  36                            struct perf_sample *sample,
  37                            struct perf_evsel *evsel __maybe_unused,
  38                            struct machine *machine)
  39 {
  40         struct addr_location al;
  41         struct thread *thread = machine__findnew_thread(machine, sample->pid,
  42                                                         sample->tid);
  43
  44         if (thread == NULL) {
  45                 pr_err("problem processing %d event, skipping it.\n",
  46                         event->header.type);
  47                 return -1;
  48         }
  49
  50         if (thread__find_map(thread, sample->cpumode, sample->ip, &al))
  51                 al.map->dso->hit = 1;
  52
  53         thread__put(thread);
  54         return 0;
  55 }
  56
  57 static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
  58                                        union perf_event *event,
  59                                        struct perf_sample *sample
  60                                        __maybe_unused,
  61                                        struct machine *machine)
  62 {
  63         struct thread *thread = machine__findnew_thread(machine,
  64                                                         event->fork.pid,
  65                                                         event->fork.tid);
  66
  67         dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
  68                     event->fork.ppid, event->fork.ptid);
  69
  70         if (thread) {
  71                 machine__remove_thread(machine, thread);
  72                 thread__put(thread);
  73         }
  74
  75         return 0;
  76 }
  77
  78 struct perf_tool build_id__mark_dso_hit_ops = {
  79         .sample = build_id__mark_dso_hit,
  80         .mmap   = perf_event__process_mmap,
  81         .mmap2  = perf_event__process_mmap2,
  82         .fork   = perf_event__process_fork,
  83         .exit   = perf_event__exit_del_thread,
  84         .attr            = perf_event__process_attr,
  85         .build_id        = perf_event__process_build_id,
  86         .ordered_events  = true,
  87 };
  88
  89 int build_id__sprintf(const u8 *build_id, int len, char *bf)
  90 {
  91         char *bid = bf;
  92         const u8 *raw = build_id;
  93         int i;
  94
  95         for (i = 0; i < len; ++i) {
  96                 sprintf(bid, "%02x", *raw);
  97                 ++raw;
  98                 bid += 2;
  99         }
 100
 101         return (bid - bf) + 1;
 102 }
 103
 104 int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
 105 {
 106         char notes[PATH_MAX];
 107         u8 build_id[BUILD_ID_SIZE];
 108         int ret;
 109
 110         if (!root_dir)
 111                 root_dir = "";
 112
 113         scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
 114
 115         ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
 116         if (ret < 0)
 117                 return ret;
 118
 119         return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
 120 }
 121
 122 int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
 123 {
 124         u8 build_id[BUILD_ID_SIZE];
 125         int ret;
 126
 127         ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
 128         if (ret < 0)
 129                 return ret;
 130         else if (ret != sizeof(build_id))
 131                 return -EINVAL;
 132
 133         return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
 134 }
 135
 136 /* asnprintf consolidates asprintf and snprintf */
 137 static int asnprintf(char **strp, size_t size, const char *fmt, ...)
 138 {
 139         va_list ap;
 140         int ret;
 141
 142         if (!strp)
 143                 return -EINVAL;
 144
 145         va_start(ap, fmt);
 146         if (*strp)
 147                 ret = vsnprintf(*strp, size, fmt, ap);
 148         else
 149                 ret = vasprintf(strp, fmt, ap);
 150         va_end(ap);
 151
 152         return ret;
 153 }
 154
 155 char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
 156                                     size_t size)
 157 {
 158         bool retry_old = true;
 159
 160         snprintf(bf, size, "%s/%s/%s/kallsyms",
 161                  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 162 retry:
 163         if (!access(bf, F_OK))
 164                 return bf;
 165         if (retry_old) {
 166                 /* Try old style kallsyms cache */
 167                 snprintf(bf, size, "%s/%s/%s",
 168                          buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 169                 retry_old = false;
 170                 goto retry;
 171         }
 172
 173         return NULL;
 174 }
 175
 176 char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size)
 177 {
 178         char *tmp = bf;
 179         int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
 180                             sbuild_id, sbuild_id + 2);
 181         if (ret < 0 || (tmp && size < (unsigned int)ret))
 182                 return NULL;
 183         return bf;
 184 }
 185
 186 char *build_id_cache__origname(const char *sbuild_id)
 187 {
 188         char *linkname;
 189         char buf[PATH_MAX];
 190         char *ret = NULL, *p;
 191         size_t offs = 5;        /* == strlen("../..") */
 192         ssize_t len;
 193
 194         linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 195         if (!linkname)
 196                 return NULL;
 197
 198         len = readlink(linkname, buf, sizeof(buf) - 1);
 199         if (len <= 0)
 200                 goto out;
 201         buf[len] = '\0';
 202
 203         /* The link should be "../..<origpath>/<sbuild_id>" */
 204         p = strrchr(buf, '/');  /* Cut off the "/<sbuild_id>" */
 205         if (p && (p > buf + offs)) {
 206                 *p = '\0';
 207                 if (buf[offs + 1] == '[')
 208                         offs++; /*
 209                                  * This is a DSO name, like [kernel.kallsyms].
 210                                  * Skip the first '/', since this is not the
 211                                  * cache of a regular file.
 212                                  */
 213                 ret = strdup(buf + offs);       /* Skip "../..[/]" */
 214         }
 215 out:
 216         free(linkname);
 217         return ret;
 218 }
 219
 220 /* Check if the given build_id cache is valid on current running system */
 221 static bool build_id_cache__valid_id(char *sbuild_id)
 222 {
 223         char real_sbuild_id[SBUILD_ID_SIZE] = "";
 224         char *pathname;
 225         int ret = 0;
 226         bool result = false;
 227
 228         pathname = build_id_cache__origname(sbuild_id);
 229         if (!pathname)
 230                 return false;
 231
 232         if (!strcmp(pathname, DSO__NAME_KALLSYMS))
 233                 ret = sysfs__sprintf_build_id("/", real_sbuild_id);
 234         else if (pathname[0] == '/')
 235                 ret = filename__sprintf_build_id(pathname, real_sbuild_id);
 236         else
 237                 ret = -EINVAL;  /* Should we support other special DSO cache? */
 238         if (ret >= 0)
 239                 result = (strcmp(sbuild_id, real_sbuild_id) == 0);
 240         free(pathname);
 241
 242         return result;
 243 }
 244
 245 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
 246                                             bool is_debug)
 247 {
 248         return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
 249             "debug" : "elf"));
 250 }
 251
 252 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
 253                              bool is_debug)
 254 {
 255         bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
 256         bool is_vdso = dso__is_vdso((struct dso *)dso);
 257         char sbuild_id[SBUILD_ID_SIZE];
 258         char *linkname;
 259         bool alloc = (bf == NULL);
 260         int ret;
 261
 262         if (!dso->has_build_id)
 263                 return NULL;
 264
 265         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 266         linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 267         if (!linkname)
 268                 return NULL;
 269
 270         /* Check if old style build_id cache */
 271         if (is_regular_file(linkname))
 272                 ret = asnprintf(&bf, size, "%s", linkname);
 273         else
 274                 ret = asnprintf(&bf, size, "%s/%s", linkname,
 275                          build_id_cache__basename(is_kallsyms, is_vdso,
 276                                                   is_debug));
 277         if (ret < 0 || (!alloc && size < (unsigned int)ret))
 278                 bf = NULL;
 279         free(linkname);
 280
 281         return bf;
 282 }
 283
 284 #define dsos__for_each_with_build_id(pos, head) \
 285         list_for_each_entry(pos, head, node)    \
 286                 if (!pos->has_build_id)         \
 287                         continue;               \
 288                 else
 289
 290 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 291                          pid_t pid, u16 misc, struct feat_fd *fd)
 292 {
 293         int err;
 294         struct build_id_event b;
 295         size_t len;
 296
 297         len = name_len + 1;
 298         len = PERF_ALIGN(len, NAME_ALIGN);
 299
 300         memset(&b, 0, sizeof(b));
 301         memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
 302         b.pid = pid;
 303         b.header.misc = misc;
 304         b.header.size = sizeof(b) + len;
 305
 306         err = do_write(fd, &b, sizeof(b));
 307         if (err < 0)
 308                 return err;
 309
 310         return write_padded(fd, name, name_len + 1, len);
 311 }
 312
 313 static int machine__write_buildid_table(struct machine *machine,
 314                                         struct feat_fd *fd)
 315 {
 316         int err = 0;
 317         struct dso *pos;
 318         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 319             umisc = PERF_RECORD_MISC_USER;
 320
 321         if (!machine__is_host(machine)) {
 322                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 323                 umisc = PERF_RECORD_MISC_GUEST_USER;
 324         }
 325
 326         dsos__for_each_with_build_id(pos, &machine->dsos.head) {
 327                 const char *name;
 328                 size_t name_len;
 329                 bool in_kernel = false;
 330
 331                 if (!pos->hit && !dso__is_vdso(pos))
 332                         continue;
 333
 334                 if (dso__is_vdso(pos)) {
 335                         name = pos->short_name;
 336                         name_len = pos->short_name_len;
 337                 } else if (dso__is_kcore(pos)) {
 338                         name = machine->mmap_name;
 339                         name_len = strlen(name);
 340                 } else {
 341                         name = pos->long_name;
 342                         name_len = pos->long_name_len;
 343                 }
 344
 345                 in_kernel = pos->kernel ||
 346                                 is_kernel_module(name,
 347                                         PERF_RECORD_MISC_CPUMODE_UNKNOWN);
 348                 err = write_buildid(name, name_len, pos->build_id, machine->pid,
 349                                     in_kernel ? kmisc : umisc, fd);
 350                 if (err)
 351                         break;
 352         }
 353
 354         return err;
 355 }
 356
 357 int perf_session__write_buildid_table(struct perf_session *session,
 358                                       struct feat_fd *fd)
 359 {
 360         struct rb_node *nd;
 361         int err = machine__write_buildid_table(&session->machines.host, fd);
 362
 363         if (err)
 364                 return err;
 365
 366         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 367                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 368                 err = machine__write_buildid_table(pos, fd);
 369                 if (err)
 370                         break;
 371         }
 372         return err;
 373 }
 374
 375 static int __dsos__hit_all(struct list_head *head)
 376 {
 377         struct dso *pos;
 378
 379         list_for_each_entry(pos, head, node)
 380                 pos->hit = true;
 381
 382         return 0;
 383 }
 384
 385 static int machine__hit_all_dsos(struct machine *machine)
 386 {
 387         return __dsos__hit_all(&machine->dsos.head);
 388 }
 389
 390 int dsos__hit_all(struct perf_session *session)
 391 {
 392         struct rb_node *nd;
 393         int err;
 394
 395         err = machine__hit_all_dsos(&session->machines.host);
 396         if (err)
 397                 return err;
 398
 399         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 400                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 401
 402                 err = machine__hit_all_dsos(pos);
 403                 if (err)
 404                         return err;
 405         }
 406
 407         return 0;
 408 }
 409
 410 void disable_buildid_cache(void)
 411 {
 412         no_buildid_cache = true;
 413 }
 414
 415 static bool lsdir_bid_head_filter(const char *name __maybe_unused,
 416                                   struct dirent *d)
 417 {
 418         return (strlen(d->d_name) == 2) &&
 419                 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
 420 }
 421
 422 static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
 423                                   struct dirent *d)
 424 {
 425         int i = 0;
 426         while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
 427                 i++;
 428         return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
 429 }
 430
 431 struct strlist *build_id_cache__list_all(bool validonly)
 432 {
 433         struct strlist *toplist, *linklist = NULL, *bidlist;
 434         struct str_node *nd, *nd2;
 435         char *topdir, *linkdir = NULL;
 436         char sbuild_id[SBUILD_ID_SIZE];
 437
 438         /* for filename__ functions */
 439         if (validonly)
 440                 symbol__init(NULL);
 441
 442         /* Open the top-level directory */
 443         if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
 444                 return NULL;
 445
 446         bidlist = strlist__new(NULL, NULL);
 447         if (!bidlist)
 448                 goto out;
 449
 450         toplist = lsdir(topdir, lsdir_bid_head_filter);
 451         if (!toplist) {
 452                 pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
 453                 /* If there is no buildid cache, return an empty list */
 454                 if (errno == ENOENT)
 455                         goto out;
 456                 goto err_out;
 457         }
 458
 459         strlist__for_each_entry(nd, toplist) {
 460                 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
 461                         goto err_out;
 462                 /* Open the lower-level directory */
 463                 linklist = lsdir(linkdir, lsdir_bid_tail_filter);
 464                 if (!linklist) {
 465                         pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
 466                         goto err_out;
 467                 }
 468                 strlist__for_each_entry(nd2, linklist) {
 469                         if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
 470                                      nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
 471                                 goto err_out;
 472                         if (validonly && !build_id_cache__valid_id(sbuild_id))
 473                                 continue;
 474                         if (strlist__add(bidlist, sbuild_id) < 0)
 475                                 goto err_out;
 476                 }
 477                 strlist__delete(linklist);
 478                 zfree(&linkdir);
 479         }
 480
 481 out_free:
 482         strlist__delete(toplist);
 483 out:
 484         free(topdir);
 485
 486         return bidlist;
 487
 488 err_out:
 489         strlist__delete(linklist);
 490         zfree(&linkdir);
 491         strlist__delete(bidlist);
 492         bidlist = NULL;
 493         goto out_free;
 494 }
 495
 496 static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
 497 {
 498         size_t i;
 499
 500         for (i = 0; i < len; i++) {
 501                 if (!isxdigit(maybe_sbuild_id[i]))
 502                         return false;
 503         }
 504         return true;
 505 }
 506
 507 /* Return the valid complete build-id */
 508 char *build_id_cache__complement(const char *incomplete_sbuild_id)
 509 {
 510         struct strlist *bidlist;
 511         struct str_node *nd, *cand = NULL;
 512         char *sbuild_id = NULL;
 513         size_t len = strlen(incomplete_sbuild_id);
 514
 515         if (len >= SBUILD_ID_SIZE ||
 516             !str_is_build_id(incomplete_sbuild_id, len))
 517                 return NULL;
 518
 519         bidlist = build_id_cache__list_all(true);
 520         if (!bidlist)
 521                 return NULL;
 522
 523         strlist__for_each_entry(nd, bidlist) {
 524                 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
 525                         continue;
 526                 if (cand) {     /* Error: There are more than 2 candidates. */
 527                         cand = NULL;
 528                         break;
 529                 }
 530                 cand = nd;
 531         }
 532         if (cand)
 533                 sbuild_id = strdup(cand->s);
 534         strlist__delete(bidlist);
 535
 536         return sbuild_id;
 537 }
 538
 539 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
 540                                struct nsinfo *nsi, bool is_kallsyms,
 541                                bool is_vdso)
 542 {
 543         char *realname = (char *)name, *filename;
 544         bool slash = is_kallsyms || is_vdso;
 545
 546         if (!slash) {
 547                 realname = nsinfo__realpath(name, nsi);
 548                 if (!realname)
 549                         return NULL;
 550         }
 551
 552         if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
 553                      is_vdso ? DSO__NAME_VDSO : realname,
 554                      sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
 555                 filename = NULL;
 556
 557         if (!slash)
 558                 free(realname);
 559
 560         return filename;
 561 }
 562
 563 int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi,
 564                                    struct strlist **result)
 565 {
 566         char *dir_name;
 567         int ret = 0;
 568
 569         dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false);
 570         if (!dir_name)
 571                 return -ENOMEM;
 572
 573         *result = lsdir(dir_name, lsdir_no_dot_filter);
 574         if (!*result)
 575                 ret = -errno;
 576         free(dir_name);
 577
 578         return ret;
 579 }
 580
 581 #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
 582 static int build_id_cache__add_sdt_cache(const char *sbuild_id,
 583                                           const char *realname,
 584                                           struct nsinfo *nsi)
 585 {
 586         struct probe_cache *cache;
 587         int ret;
 588         struct nscookie nsc;
 589
 590         cache = probe_cache__new(sbuild_id, nsi);
 591         if (!cache)
 592                 return -1;
 593
 594         nsinfo__mountns_enter(nsi, &nsc);
 595         ret = probe_cache__scan_sdt(cache, realname);
 596         nsinfo__mountns_exit(&nsc);
 597         if (ret >= 0) {
 598                 pr_debug4("Found %d SDTs in %s\n", ret, realname);
 599                 if (probe_cache__commit(cache) < 0)
 600                         ret = -1;
 601         }
 602         probe_cache__delete(cache);
 603         return ret;
 604 }
 605 #else
 606 #define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0)
 607 #endif
 608
 609 static char *build_id_cache__find_debug(const char *sbuild_id,
 610                                         struct nsinfo *nsi)
 611 {
 612         char *realname = NULL;
 613         char *debugfile;
 614         struct nscookie nsc;
 615         size_t len = 0;
 616
 617         debugfile = calloc(1, PATH_MAX);
 618         if (!debugfile)
 619                 goto out;
 620
 621         len = __symbol__join_symfs(debugfile, PATH_MAX,
 622                                    "/usr/lib/debug/.build-id/");
 623         snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id,
 624                  sbuild_id + 2);
 625
 626         nsinfo__mountns_enter(nsi, &nsc);
 627         realname = realpath(debugfile, NULL);
 628         if (realname && access(realname, R_OK))
 629                 zfree(&realname);
 630         nsinfo__mountns_exit(&nsc);
 631 out:
 632         free(debugfile);
 633         return realname;
 634 }
 635
 636 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 637                           struct nsinfo *nsi, bool is_kallsyms, bool is_vdso)
 638 {
 639         const size_t size = PATH_MAX;
 640         char *realname = NULL, *filename = NULL, *dir_name = NULL,
 641              *linkname = zalloc(size), *tmp;
 642         char *debugfile = NULL;
 643         int err = -1;
 644
 645         if (!is_kallsyms) {
 646                 if (!is_vdso)
 647                         realname = nsinfo__realpath(name, nsi);
 648                 else
 649                         realname = realpath(name, NULL);
 650                 if (!realname)
 651                         goto out_free;
 652         }
 653
 654         dir_name = build_id_cache__cachedir(sbuild_id, name, nsi, is_kallsyms,
 655                                             is_vdso);
 656         if (!dir_name)
 657                 goto out_free;
 658
 659         /* Remove old style build-id cache */
 660         if (is_regular_file(dir_name))
 661                 if (unlink(dir_name))
 662                         goto out_free;
 663
 664         if (mkdir_p(dir_name, 0755))
 665                 goto out_free;
 666
 667         /* Save the allocated buildid dirname */
 668         if (asprintf(&filename, "%s/%s", dir_name,
 669                      build_id_cache__basename(is_kallsyms, is_vdso,
 670                      false)) < 0) {
 671                 filename = NULL;
 672                 goto out_free;
 673         }
 674
 675         if (access(filename, F_OK)) {
 676                 if (is_kallsyms) {
 677                         if (copyfile("/proc/kallsyms", filename))
 678                                 goto out_free;
 679                 } else if (nsi && nsi->need_setns) {
 680                         if (copyfile_ns(name, filename, nsi))
 681                                 goto out_free;
 682                 } else if (link(realname, filename) && errno != EEXIST &&
 683                                 copyfile(name, filename))
 684                         goto out_free;
 685         }
 686
 687         /* Some binaries are stripped, but have .debug files with their symbol
 688          * table.  Check to see if we can locate one of those, since the elf
 689          * file itself may not be very useful to users of our tools without a
 690          * symtab.
 691          */
 692         if (!is_kallsyms && !is_vdso &&
 693             strncmp(".ko", name + strlen(name) - 3, 3)) {
 694                 debugfile = build_id_cache__find_debug(sbuild_id, nsi);
 695                 if (debugfile) {
 696                         zfree(&filename);
 697                         if (asprintf(&filename, "%s/%s", dir_name,
 698                             build_id_cache__basename(false, false, true)) < 0) {
 699                                 filename = NULL;
 700                                 goto out_free;
 701                         }
 702                         if (access(filename, F_OK)) {
 703                                 if (nsi && nsi->need_setns) {
 704                                         if (copyfile_ns(debugfile, filename,
 705                                                         nsi))
 706                                                 goto out_free;
 707                                 } else if (link(debugfile, filename) &&
 708                                                 errno != EEXIST &&
 709                                                 copyfile(debugfile, filename))
 710                                         goto out_free;
 711                         }
 712                 }
 713         }
 714
 715         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 716                 goto out_free;
 717         tmp = strrchr(linkname, '/');
 718         *tmp = '\0';
 719
 720         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 721                 goto out_free;
 722
 723         *tmp = '/';
 724         tmp = dir_name + strlen(buildid_dir) - 5;
 725         memcpy(tmp, "../..", 5);
 726
 727         if (symlink(tmp, linkname) == 0)
 728                 err = 0;
 729
 730         /* Update SDT cache : error is just warned */
 731         if (realname &&
 732             build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0)
 733                 pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
 734
 735 out_free:
 736         if (!is_kallsyms)
 737                 free(realname);
 738         free(filename);
 739         free(debugfile);
 740         free(dir_name);
 741         free(linkname);
 742         return err;
 743 }
 744
 745 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 746                                  const char *name, struct nsinfo *nsi,
 747                                  bool is_kallsyms, bool is_vdso)
 748 {
 749         char sbuild_id[SBUILD_ID_SIZE];
 750
 751         build_id__sprintf(build_id, build_id_size, sbuild_id);
 752
 753         return build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms,
 754                                      is_vdso);
 755 }
 756
 757 bool build_id_cache__cached(const char *sbuild_id)
 758 {
 759         bool ret = false;
 760         char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
 761
 762         if (filename && !access(filename, F_OK))
 763                 ret = true;
 764         free(filename);
 765
 766         return ret;
 767 }
 768
 769 int build_id_cache__remove_s(const char *sbuild_id)
 770 {
 771         const size_t size = PATH_MAX;
 772         char *filename = zalloc(size),
 773              *linkname = zalloc(size), *tmp;
 774         int err = -1;
 775
 776         if (filename == NULL || linkname == NULL)
 777                 goto out_free;
 778
 779         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 780                 goto out_free;
 781
 782         if (access(linkname, F_OK))
 783                 goto out_free;
 784
 785         if (readlink(linkname, filename, size - 1) < 0)
 786                 goto out_free;
 787
 788         if (unlink(linkname))
 789                 goto out_free;
 790
 791         /*
 792          * Since the link is relative, we must make it absolute:
 793          */
 794         tmp = strrchr(linkname, '/') + 1;
 795         snprintf(tmp, size - (tmp - linkname), "%s", filename);
 796
 797         if (rm_rf(linkname))
 798                 goto out_free;
 799
 800         err = 0;
 801 out_free:
 802         free(filename);
 803         free(linkname);
 804         return err;
 805 }
 806
 807 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 808 {
 809         bool is_kallsyms = dso__is_kallsyms(dso);
 810         bool is_vdso = dso__is_vdso(dso);
 811         const char *name = dso->long_name;
 812
 813         if (dso__is_kcore(dso)) {
 814                 is_kallsyms = true;
 815                 name = machine->mmap_name;
 816         }
 817         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 818                                      dso->nsinfo, is_kallsyms, is_vdso);
 819 }
 820
 821 static int __dsos__cache_build_ids(struct list_head *head,
 822                                    struct machine *machine)
 823 {
 824         struct dso *pos;
 825         int err = 0;
 826
 827         dsos__for_each_with_build_id(pos, head)
 828                 if (dso__cache_build_id(pos, machine))
 829                         err = -1;
 830
 831         return err;
 832 }
 833
 834 static int machine__cache_build_ids(struct machine *machine)
 835 {
 836         return __dsos__cache_build_ids(&machine->dsos.head, machine);
 837 }
 838
 839 int perf_session__cache_build_ids(struct perf_session *session)
 840 {
 841         struct rb_node *nd;
 842         int ret;
 843
 844         if (no_buildid_cache)
 845                 return 0;
 846
 847         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 848                 return -1;
 849
 850         ret = machine__cache_build_ids(&session->machines.host);
 851
 852         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 853                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 854                 ret |= machine__cache_build_ids(pos);
 855         }
 856         return ret ? -1 : 0;
 857 }
 858
 859 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 860 {
 861         return __dsos__read_build_ids(&machine->dsos.head, with_hits);
 862 }
 863
 864 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 865 {
 866         struct rb_node *nd;
 867         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 868
 869         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 870                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 871                 ret |= machine__read_build_ids(pos, with_hits);
 872         }
 873
 874         return ret;
 875 }