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 /* The caller is responsible to free the returned buffer. */
 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                                             bool is_debug)
 248 {
 249         return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
 250             "debug" : "elf"));
 251 }
 252
 253 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
 254                              bool is_debug)
 255 {
 256         bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
 257         bool is_vdso = dso__is_vdso((struct dso *)dso);
 258         char sbuild_id[SBUILD_ID_SIZE];
 259         char *linkname;
 260         bool alloc = (bf == NULL);
 261         int ret;
 262
 263         if (!dso->has_build_id)
 264                 return NULL;
 265
 266         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 267         linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 268         if (!linkname)
 269                 return NULL;
 270
 271         /* Check if old style build_id cache */
 272         if (is_regular_file(linkname))
 273                 ret = asnprintf(&bf, size, "%s", linkname);
 274         else
 275                 ret = asnprintf(&bf, size, "%s/%s", linkname,
 276                          build_id_cache__basename(is_kallsyms, is_vdso,
 277                                                   is_debug));
 278         if (ret < 0 || (!alloc && size < (unsigned int)ret))
 279                 bf = NULL;
 280         free(linkname);
 281
 282         return bf;
 283 }
 284
 285 #define dsos__for_each_with_build_id(pos, head) \
 286         list_for_each_entry(pos, head, node)    \
 287                 if (!pos->has_build_id)         \
 288                         continue;               \
 289                 else
 290
 291 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 292                          pid_t pid, u16 misc, struct feat_fd *fd)
 293 {
 294         int err;
 295         struct build_id_event b;
 296         size_t len;
 297
 298         len = name_len + 1;
 299         len = PERF_ALIGN(len, NAME_ALIGN);
 300
 301         memset(&b, 0, sizeof(b));
 302         memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
 303         b.pid = pid;
 304         b.header.misc = misc;
 305         b.header.size = sizeof(b) + len;
 306
 307         err = do_write(fd, &b, sizeof(b));
 308         if (err < 0)
 309                 return err;
 310
 311         return write_padded(fd, name, name_len + 1, len);
 312 }
 313
 314 static int machine__write_buildid_table(struct machine *machine,
 315                                         struct feat_fd *fd)
 316 {
 317         int err = 0;
 318         struct dso *pos;
 319         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 320             umisc = PERF_RECORD_MISC_USER;
 321
 322         if (!machine__is_host(machine)) {
 323                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 324                 umisc = PERF_RECORD_MISC_GUEST_USER;
 325         }
 326
 327         dsos__for_each_with_build_id(pos, &machine->dsos.head) {
 328                 const char *name;
 329                 size_t name_len;
 330                 bool in_kernel = false;
 331
 332                 if (!pos->hit && !dso__is_vdso(pos))
 333                         continue;
 334
 335                 if (dso__is_vdso(pos)) {
 336                         name = pos->short_name;
 337                         name_len = pos->short_name_len;
 338                 } else if (dso__is_kcore(pos)) {
 339                         name = machine->mmap_name;
 340                         name_len = strlen(name);
 341                 } else {
 342                         name = pos->long_name;
 343                         name_len = pos->long_name_len;
 344                 }
 345
 346                 in_kernel = pos->kernel ||
 347                                 is_kernel_module(name,
 348                                         PERF_RECORD_MISC_CPUMODE_UNKNOWN);
 349                 err = write_buildid(name, name_len, pos->build_id, machine->pid,
 350                                     in_kernel ? kmisc : umisc, fd);
 351                 if (err)
 352                         break;
 353         }
 354
 355         return err;
 356 }
 357
 358 int perf_session__write_buildid_table(struct perf_session *session,
 359                                       struct feat_fd *fd)
 360 {
 361         struct rb_node *nd;
 362         int err = machine__write_buildid_table(&session->machines.host, fd);
 363
 364         if (err)
 365                 return err;
 366
 367         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 368                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 369                 err = machine__write_buildid_table(pos, fd);
 370                 if (err)
 371                         break;
 372         }
 373         return err;
 374 }
 375
 376 static int __dsos__hit_all(struct list_head *head)
 377 {
 378         struct dso *pos;
 379
 380         list_for_each_entry(pos, head, node)
 381                 pos->hit = true;
 382
 383         return 0;
 384 }
 385
 386 static int machine__hit_all_dsos(struct machine *machine)
 387 {
 388         return __dsos__hit_all(&machine->dsos.head);
 389 }
 390
 391 int dsos__hit_all(struct perf_session *session)
 392 {
 393         struct rb_node *nd;
 394         int err;
 395
 396         err = machine__hit_all_dsos(&session->machines.host);
 397         if (err)
 398                 return err;
 399
 400         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 401                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 402
 403                 err = machine__hit_all_dsos(pos);
 404                 if (err)
 405                         return err;
 406         }
 407
 408         return 0;
 409 }
 410
 411 void disable_buildid_cache(void)
 412 {
 413         no_buildid_cache = true;
 414 }
 415
 416 static bool lsdir_bid_head_filter(const char *name __maybe_unused,
 417                                   struct dirent *d)
 418 {
 419         return (strlen(d->d_name) == 2) &&
 420                 isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
 421 }
 422
 423 static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
 424                                   struct dirent *d)
 425 {
 426         int i = 0;
 427         while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
 428                 i++;
 429         return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
 430 }
 431
 432 struct strlist *build_id_cache__list_all(bool validonly)
 433 {
 434         struct strlist *toplist, *linklist = NULL, *bidlist;
 435         struct str_node *nd, *nd2;
 436         char *topdir, *linkdir = NULL;
 437         char sbuild_id[SBUILD_ID_SIZE];
 438
 439         /* for filename__ functions */
 440         if (validonly)
 441                 symbol__init(NULL);
 442
 443         /* Open the top-level directory */
 444         if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
 445                 return NULL;
 446
 447         bidlist = strlist__new(NULL, NULL);
 448         if (!bidlist)
 449                 goto out;
 450
 451         toplist = lsdir(topdir, lsdir_bid_head_filter);
 452         if (!toplist) {
 453                 pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
 454                 /* If there is no buildid cache, return an empty list */
 455                 if (errno == ENOENT)
 456                         goto out;
 457                 goto err_out;
 458         }
 459
 460         strlist__for_each_entry(nd, toplist) {
 461                 if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
 462                         goto err_out;
 463                 /* Open the lower-level directory */
 464                 linklist = lsdir(linkdir, lsdir_bid_tail_filter);
 465                 if (!linklist) {
 466                         pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
 467                         goto err_out;
 468                 }
 469                 strlist__for_each_entry(nd2, linklist) {
 470                         if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
 471                                      nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
 472                                 goto err_out;
 473                         if (validonly && !build_id_cache__valid_id(sbuild_id))
 474                                 continue;
 475                         if (strlist__add(bidlist, sbuild_id) < 0)
 476                                 goto err_out;
 477                 }
 478                 strlist__delete(linklist);
 479                 zfree(&linkdir);
 480         }
 481
 482 out_free:
 483         strlist__delete(toplist);
 484 out:
 485         free(topdir);
 486
 487         return bidlist;
 488
 489 err_out:
 490         strlist__delete(linklist);
 491         zfree(&linkdir);
 492         strlist__delete(bidlist);
 493         bidlist = NULL;
 494         goto out_free;
 495 }
 496
 497 static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
 498 {
 499         size_t i;
 500
 501         for (i = 0; i < len; i++) {
 502                 if (!isxdigit(maybe_sbuild_id[i]))
 503                         return false;
 504         }
 505         return true;
 506 }
 507
 508 /* Return the valid complete build-id */
 509 char *build_id_cache__complement(const char *incomplete_sbuild_id)
 510 {
 511         struct strlist *bidlist;
 512         struct str_node *nd, *cand = NULL;
 513         char *sbuild_id = NULL;
 514         size_t len = strlen(incomplete_sbuild_id);
 515
 516         if (len >= SBUILD_ID_SIZE ||
 517             !str_is_build_id(incomplete_sbuild_id, len))
 518                 return NULL;
 519
 520         bidlist = build_id_cache__list_all(true);
 521         if (!bidlist)
 522                 return NULL;
 523
 524         strlist__for_each_entry(nd, bidlist) {
 525                 if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
 526                         continue;
 527                 if (cand) {     /* Error: There are more than 2 candidates. */
 528                         cand = NULL;
 529                         break;
 530                 }
 531                 cand = nd;
 532         }
 533         if (cand)
 534                 sbuild_id = strdup(cand->s);
 535         strlist__delete(bidlist);
 536
 537         return sbuild_id;
 538 }
 539
 540 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
 541                                struct nsinfo *nsi, bool is_kallsyms,
 542                                bool is_vdso)
 543 {
 544         char *realname = (char *)name, *filename;
 545         bool slash = is_kallsyms || is_vdso;
 546
 547         if (!slash) {
 548                 realname = nsinfo__realpath(name, nsi);
 549                 if (!realname)
 550                         return NULL;
 551         }
 552
 553         if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
 554                      is_vdso ? DSO__NAME_VDSO : realname,
 555                      sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
 556                 filename = NULL;
 557
 558         if (!slash)
 559                 free(realname);
 560
 561         return filename;
 562 }
 563
 564 int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi,
 565                                    struct strlist **result)
 566 {
 567         char *dir_name;
 568         int ret = 0;
 569
 570         dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false);
 571         if (!dir_name)
 572                 return -ENOMEM;
 573
 574         *result = lsdir(dir_name, lsdir_no_dot_filter);
 575         if (!*result)
 576                 ret = -errno;
 577         free(dir_name);
 578
 579         return ret;
 580 }
 581
 582 #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
 583 static int build_id_cache__add_sdt_cache(const char *sbuild_id,
 584                                           const char *realname,
 585                                           struct nsinfo *nsi)
 586 {
 587         struct probe_cache *cache;
 588         int ret;
 589         struct nscookie nsc;
 590
 591         cache = probe_cache__new(sbuild_id, nsi);
 592         if (!cache)
 593                 return -1;
 594
 595         nsinfo__mountns_enter(nsi, &nsc);
 596         ret = probe_cache__scan_sdt(cache, realname);
 597         nsinfo__mountns_exit(&nsc);
 598         if (ret >= 0) {
 599                 pr_debug4("Found %d SDTs in %s\n", ret, realname);
 600                 if (probe_cache__commit(cache) < 0)
 601                         ret = -1;
 602         }
 603         probe_cache__delete(cache);
 604         return ret;
 605 }
 606 #else
 607 #define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0)
 608 #endif
 609
 610 static char *build_id_cache__find_debug(const char *sbuild_id,
 611                                         struct nsinfo *nsi)
 612 {
 613         char *realname = NULL;
 614         char *debugfile;
 615         struct nscookie nsc;
 616         size_t len = 0;
 617
 618         debugfile = calloc(1, PATH_MAX);
 619         if (!debugfile)
 620                 goto out;
 621
 622         len = __symbol__join_symfs(debugfile, PATH_MAX,
 623                                    "/usr/lib/debug/.build-id/");
 624         snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id,
 625                  sbuild_id + 2);
 626
 627         nsinfo__mountns_enter(nsi, &nsc);
 628         realname = realpath(debugfile, NULL);
 629         if (realname && access(realname, R_OK))
 630                 zfree(&realname);
 631         nsinfo__mountns_exit(&nsc);
 632 out:
 633         free(debugfile);
 634         return realname;
 635 }
 636
 637 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 638                           struct nsinfo *nsi, bool is_kallsyms, bool is_vdso)
 639 {
 640         const size_t size = PATH_MAX;
 641         char *realname = NULL, *filename = NULL, *dir_name = NULL,
 642              *linkname = zalloc(size), *tmp;
 643         char *debugfile = NULL;
 644         int err = -1;
 645
 646         if (!is_kallsyms) {
 647                 if (!is_vdso)
 648                         realname = nsinfo__realpath(name, nsi);
 649                 else
 650                         realname = realpath(name, NULL);
 651                 if (!realname)
 652                         goto out_free;
 653         }
 654
 655         dir_name = build_id_cache__cachedir(sbuild_id, name, nsi, is_kallsyms,
 656                                             is_vdso);
 657         if (!dir_name)
 658                 goto out_free;
 659
 660         /* Remove old style build-id cache */
 661         if (is_regular_file(dir_name))
 662                 if (unlink(dir_name))
 663                         goto out_free;
 664
 665         if (mkdir_p(dir_name, 0755))
 666                 goto out_free;
 667
 668         /* Save the allocated buildid dirname */
 669         if (asprintf(&filename, "%s/%s", dir_name,
 670                      build_id_cache__basename(is_kallsyms, is_vdso,
 671                      false)) < 0) {
 672                 filename = NULL;
 673                 goto out_free;
 674         }
 675
 676         if (access(filename, F_OK)) {
 677                 if (is_kallsyms) {
 678                         if (copyfile("/proc/kallsyms", filename))
 679                                 goto out_free;
 680                 } else if (nsi && nsi->need_setns) {
 681                         if (copyfile_ns(name, filename, nsi))
 682                                 goto out_free;
 683                 } else if (link(realname, filename) && errno != EEXIST &&
 684                                 copyfile(name, filename))
 685                         goto out_free;
 686         }
 687
 688         /* Some binaries are stripped, but have .debug files with their symbol
 689          * table.  Check to see if we can locate one of those, since the elf
 690          * file itself may not be very useful to users of our tools without a
 691          * symtab.
 692          */
 693         if (!is_kallsyms && !is_vdso &&
 694             strncmp(".ko", name + strlen(name) - 3, 3)) {
 695                 debugfile = build_id_cache__find_debug(sbuild_id, nsi);
 696                 if (debugfile) {
 697                         zfree(&filename);
 698                         if (asprintf(&filename, "%s/%s", dir_name,
 699                             build_id_cache__basename(false, false, true)) < 0) {
 700                                 filename = NULL;
 701                                 goto out_free;
 702                         }
 703                         if (access(filename, F_OK)) {
 704                                 if (nsi && nsi->need_setns) {
 705                                         if (copyfile_ns(debugfile, filename,
 706                                                         nsi))
 707                                                 goto out_free;
 708                                 } else if (link(debugfile, filename) &&
 709                                                 errno != EEXIST &&
 710                                                 copyfile(debugfile, filename))
 711                                         goto out_free;
 712                         }
 713                 }
 714         }
 715
 716         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 717                 goto out_free;
 718         tmp = strrchr(linkname, '/');
 719         *tmp = '\0';
 720
 721         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 722                 goto out_free;
 723
 724         *tmp = '/';
 725         tmp = dir_name + strlen(buildid_dir) - 5;
 726         memcpy(tmp, "../..", 5);
 727
 728         if (symlink(tmp, linkname) == 0)
 729                 err = 0;
 730
 731         /* Update SDT cache : error is just warned */
 732         if (realname &&
 733             build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0)
 734                 pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
 735
 736 out_free:
 737         if (!is_kallsyms)
 738                 free(realname);
 739         free(filename);
 740         free(debugfile);
 741         free(dir_name);
 742         free(linkname);
 743         return err;
 744 }
 745
 746 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 747                                  const char *name, struct nsinfo *nsi,
 748                                  bool is_kallsyms, bool is_vdso)
 749 {
 750         char sbuild_id[SBUILD_ID_SIZE];
 751
 752         build_id__sprintf(build_id, build_id_size, sbuild_id);
 753
 754         return build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms,
 755                                      is_vdso);
 756 }
 757
 758 bool build_id_cache__cached(const char *sbuild_id)
 759 {
 760         bool ret = false;
 761         char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
 762
 763         if (filename && !access(filename, F_OK))
 764                 ret = true;
 765         free(filename);
 766
 767         return ret;
 768 }
 769
 770 int build_id_cache__remove_s(const char *sbuild_id)
 771 {
 772         const size_t size = PATH_MAX;
 773         char *filename = zalloc(size),
 774              *linkname = zalloc(size), *tmp;
 775         int err = -1;
 776
 777         if (filename == NULL || linkname == NULL)
 778                 goto out_free;
 779
 780         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 781                 goto out_free;
 782
 783         if (access(linkname, F_OK))
 784                 goto out_free;
 785
 786         if (readlink(linkname, filename, size - 1) < 0)
 787                 goto out_free;
 788
 789         if (unlink(linkname))
 790                 goto out_free;
 791
 792         /*
 793          * Since the link is relative, we must make it absolute:
 794          */
 795         tmp = strrchr(linkname, '/') + 1;
 796         snprintf(tmp, size - (tmp - linkname), "%s", filename);
 797
 798         if (rm_rf(linkname))
 799                 goto out_free;
 800
 801         err = 0;
 802 out_free:
 803         free(filename);
 804         free(linkname);
 805         return err;
 806 }
 807
 808 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 809 {
 810         bool is_kallsyms = dso__is_kallsyms(dso);
 811         bool is_vdso = dso__is_vdso(dso);
 812         const char *name = dso->long_name;
 813
 814         if (dso__is_kcore(dso)) {
 815                 is_kallsyms = true;
 816                 name = machine->mmap_name;
 817         }
 818         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 819                                      dso->nsinfo, is_kallsyms, is_vdso);
 820 }
 821
 822 static int __dsos__cache_build_ids(struct list_head *head,
 823                                    struct machine *machine)
 824 {
 825         struct dso *pos;
 826         int err = 0;
 827
 828         dsos__for_each_with_build_id(pos, head)
 829                 if (dso__cache_build_id(pos, machine))
 830                         err = -1;
 831
 832         return err;
 833 }
 834
 835 static int machine__cache_build_ids(struct machine *machine)
 836 {
 837         return __dsos__cache_build_ids(&machine->dsos.head, machine);
 838 }
 839
 840 int perf_session__cache_build_ids(struct perf_session *session)
 841 {
 842         struct rb_node *nd;
 843         int ret;
 844
 845         if (no_buildid_cache)
 846                 return 0;
 847
 848         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 849                 return -1;
 850
 851         ret = machine__cache_build_ids(&session->machines.host);
 852
 853         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 854                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 855                 ret |= machine__cache_build_ids(pos);
 856         }
 857         return ret ? -1 : 0;
 858 }
 859
 860 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 861 {
 862         return __dsos__read_build_ids(&machine->dsos.head, with_hits);
 863 }
 864
 865 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 866 {
 867         struct rb_node *nd;
 868         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 869
 870         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 871                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 872                 ret |= machine__read_build_ids(pos, with_hits);
 873         }
 874
 875         return ret;
 876 }