linux/tools/perf/util/build-id.c
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   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" // lsdir(), mkdir_p(), rm_rf()
  11#include <dirent.h>
  12#include <errno.h>
  13#include <stdio.h>
  14#include <sys/stat.h>
  15#include <sys/types.h>
  16#include "util/copyfile.h"
  17#include "dso.h"
  18#include "build-id.h"
  19#include "event.h"
  20#include "namespaces.h"
  21#include "map.h"
  22#include "symbol.h"
  23#include "thread.h"
  24#include <linux/kernel.h>
  25#include "debug.h"
  26#include "session.h"
  27#include "tool.h"
  28#include "header.h"
  29#include "vdso.h"
  30#include "path.h"
  31#include "probe-file.h"
  32#include "strlist.h"
  33
  34#ifdef HAVE_DEBUGINFOD_SUPPORT
  35#include <elfutils/debuginfod.h>
  36#endif
  37
  38#include <linux/ctype.h>
  39#include <linux/zalloc.h>
  40#include <linux/string.h>
  41#include <asm/bug.h>
  42
  43static bool no_buildid_cache;
  44
  45int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
  46                           union perf_event *event,
  47                           struct perf_sample *sample,
  48                           struct evsel *evsel __maybe_unused,
  49                           struct machine *machine)
  50{
  51        struct addr_location al;
  52        struct thread *thread = machine__findnew_thread(machine, sample->pid,
  53                                                        sample->tid);
  54
  55        if (thread == NULL) {
  56                pr_err("problem processing %d event, skipping it.\n",
  57                        event->header.type);
  58                return -1;
  59        }
  60
  61        if (thread__find_map(thread, sample->cpumode, sample->ip, &al))
  62                al.map->dso->hit = 1;
  63
  64        thread__put(thread);
  65        return 0;
  66}
  67
  68static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
  69                                       union perf_event *event,
  70                                       struct perf_sample *sample
  71                                       __maybe_unused,
  72                                       struct machine *machine)
  73{
  74        struct thread *thread = machine__findnew_thread(machine,
  75                                                        event->fork.pid,
  76                                                        event->fork.tid);
  77
  78        dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
  79                    event->fork.ppid, event->fork.ptid);
  80
  81        if (thread) {
  82                machine__remove_thread(machine, thread);
  83                thread__put(thread);
  84        }
  85
  86        return 0;
  87}
  88
  89struct perf_tool build_id__mark_dso_hit_ops = {
  90        .sample = build_id__mark_dso_hit,
  91        .mmap   = perf_event__process_mmap,
  92        .mmap2  = perf_event__process_mmap2,
  93        .fork   = perf_event__process_fork,
  94        .exit   = perf_event__exit_del_thread,
  95        .attr            = perf_event__process_attr,
  96        .build_id        = perf_event__process_build_id,
  97        .ordered_events  = true,
  98};
  99
 100int build_id__sprintf(const struct build_id *build_id, char *bf)
 101{
 102        char *bid = bf;
 103        const u8 *raw = build_id->data;
 104        size_t i;
 105
 106        bf[0] = 0x0;
 107
 108        for (i = 0; i < build_id->size; ++i) {
 109                sprintf(bid, "%02x", *raw);
 110                ++raw;
 111                bid += 2;
 112        }
 113
 114        return (bid - bf) + 1;
 115}
 116
 117int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
 118{
 119        char notes[PATH_MAX];
 120        struct build_id bid;
 121        int ret;
 122
 123        if (!root_dir)
 124                root_dir = "";
 125
 126        scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
 127
 128        ret = sysfs__read_build_id(notes, &bid);
 129        if (ret < 0)
 130                return ret;
 131
 132        return build_id__sprintf(&bid, sbuild_id);
 133}
 134
 135int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
 136{
 137        struct build_id bid;
 138        int ret;
 139
 140        ret = filename__read_build_id(pathname, &bid);
 141        if (ret < 0)
 142                return ret;
 143
 144        return build_id__sprintf(&bid, sbuild_id);
 145}
 146
 147/* asnprintf consolidates asprintf and snprintf */
 148static int asnprintf(char **strp, size_t size, const char *fmt, ...)
 149{
 150        va_list ap;
 151        int ret;
 152
 153        if (!strp)
 154                return -EINVAL;
 155
 156        va_start(ap, fmt);
 157        if (*strp)
 158                ret = vsnprintf(*strp, size, fmt, ap);
 159        else
 160                ret = vasprintf(strp, fmt, ap);
 161        va_end(ap);
 162
 163        return ret;
 164}
 165
 166char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
 167                                    size_t size)
 168{
 169        bool retry_old = true;
 170
 171        snprintf(bf, size, "%s/%s/%s/kallsyms",
 172                 buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 173retry:
 174        if (!access(bf, F_OK))
 175                return bf;
 176        if (retry_old) {
 177                /* Try old style kallsyms cache */
 178                snprintf(bf, size, "%s/%s/%s",
 179                         buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 180                retry_old = false;
 181                goto retry;
 182        }
 183
 184        return NULL;
 185}
 186
 187char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size)
 188{
 189        char *tmp = bf;
 190        int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
 191                            sbuild_id, sbuild_id + 2);
 192        if (ret < 0 || (tmp && size < (unsigned int)ret))
 193                return NULL;
 194        return bf;
 195}
 196
 197/* The caller is responsible to free the returned buffer. */
 198char *build_id_cache__origname(const char *sbuild_id)
 199{
 200        char *linkname;
 201        char buf[PATH_MAX];
 202        char *ret = NULL, *p;
 203        size_t offs = 5;        /* == strlen("../..") */
 204        ssize_t len;
 205
 206        linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 207        if (!linkname)
 208                return NULL;
 209
 210        len = readlink(linkname, buf, sizeof(buf) - 1);
 211        if (len <= 0)
 212                goto out;
 213        buf[len] = '\0';
 214
 215        /* The link should be "../..<origpath>/<sbuild_id>" */
 216        p = strrchr(buf, '/');  /* Cut off the "/<sbuild_id>" */
 217        if (p && (p > buf + offs)) {
 218                *p = '\0';
 219                if (buf[offs + 1] == '[')
 220                        offs++; /*
 221                                 * This is a DSO name, like [kernel.kallsyms].
 222                                 * Skip the first '/', since this is not the
 223                                 * cache of a regular file.
 224                                 */
 225                ret = strdup(buf + offs);       /* Skip "../..[/]" */
 226        }
 227out:
 228        free(linkname);
 229        return ret;
 230}
 231
 232/* Check if the given build_id cache is valid on current running system */
 233static bool build_id_cache__valid_id(char *sbuild_id)
 234{
 235        char real_sbuild_id[SBUILD_ID_SIZE] = "";
 236        char *pathname;
 237        int ret = 0;
 238        bool result = false;
 239
 240        pathname = build_id_cache__origname(sbuild_id);
 241        if (!pathname)
 242                return false;
 243
 244        if (!strcmp(pathname, DSO__NAME_KALLSYMS))
 245                ret = sysfs__sprintf_build_id("/", real_sbuild_id);
 246        else if (pathname[0] == '/')
 247                ret = filename__sprintf_build_id(pathname, real_sbuild_id);
 248        else
 249                ret = -EINVAL;  /* Should we support other special DSO cache? */
 250        if (ret >= 0)
 251                result = (strcmp(sbuild_id, real_sbuild_id) == 0);
 252        free(pathname);
 253
 254        return result;
 255}
 256
 257static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
 258                                            bool is_debug)
 259{
 260        return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
 261            "debug" : "elf"));
 262}
 263
 264char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
 265                               bool is_debug, bool is_kallsyms)
 266{
 267        bool is_vdso = dso__is_vdso((struct dso *)dso);
 268        char sbuild_id[SBUILD_ID_SIZE];
 269        char *linkname;
 270        bool alloc = (bf == NULL);
 271        int ret;
 272
 273        if (!dso->has_build_id)
 274                return NULL;
 275
 276        build_id__sprintf(&dso->bid, sbuild_id);
 277        linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 278        if (!linkname)
 279                return NULL;
 280
 281        /* Check if old style build_id cache */
 282        if (is_regular_file(linkname))
 283                ret = asnprintf(&bf, size, "%s", linkname);
 284        else
 285                ret = asnprintf(&bf, size, "%s/%s", linkname,
 286                         build_id_cache__basename(is_kallsyms, is_vdso,
 287                                                  is_debug));
 288        if (ret < 0 || (!alloc && size < (unsigned int)ret))
 289                bf = NULL;
 290        free(linkname);
 291
 292        return bf;
 293}
 294
 295char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
 296                             bool is_debug)
 297{
 298        bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
 299
 300        return __dso__build_id_filename(dso, bf, size, is_debug, is_kallsyms);
 301}
 302
 303#define dsos__for_each_with_build_id(pos, head) \
 304        list_for_each_entry(pos, head, node)    \
 305                if (!pos->has_build_id)         \
 306                        continue;               \
 307                else
 308
 309static int write_buildid(const char *name, size_t name_len, struct build_id *bid,
 310                         pid_t pid, u16 misc, struct feat_fd *fd)
 311{
 312        int err;
 313        struct perf_record_header_build_id b;
 314        size_t len;
 315
 316        len = name_len + 1;
 317        len = PERF_ALIGN(len, NAME_ALIGN);
 318
 319        memset(&b, 0, sizeof(b));
 320        memcpy(&b.data, bid->data, bid->size);
 321        b.size = (u8) bid->size;
 322        misc |= PERF_RECORD_MISC_BUILD_ID_SIZE;
 323        b.pid = pid;
 324        b.header.misc = misc;
 325        b.header.size = sizeof(b) + len;
 326
 327        err = do_write(fd, &b, sizeof(b));
 328        if (err < 0)
 329                return err;
 330
 331        return write_padded(fd, name, name_len + 1, len);
 332}
 333
 334static int machine__write_buildid_table(struct machine *machine,
 335                                        struct feat_fd *fd)
 336{
 337        int err = 0;
 338        struct dso *pos;
 339        u16 kmisc = PERF_RECORD_MISC_KERNEL,
 340            umisc = PERF_RECORD_MISC_USER;
 341
 342        if (!machine__is_host(machine)) {
 343                kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 344                umisc = PERF_RECORD_MISC_GUEST_USER;
 345        }
 346
 347        dsos__for_each_with_build_id(pos, &machine->dsos.head) {
 348                const char *name;
 349                size_t name_len;
 350                bool in_kernel = false;
 351
 352                if (!pos->hit && !dso__is_vdso(pos))
 353                        continue;
 354
 355                if (dso__is_vdso(pos)) {
 356                        name = pos->short_name;
 357                        name_len = pos->short_name_len;
 358                } else if (dso__is_kcore(pos)) {
 359                        name = machine->mmap_name;
 360                        name_len = strlen(name);
 361                } else {
 362                        name = pos->long_name;
 363                        name_len = pos->long_name_len;
 364                }
 365
 366                in_kernel = pos->kernel ||
 367                                is_kernel_module(name,
 368                                        PERF_RECORD_MISC_CPUMODE_UNKNOWN);
 369                err = write_buildid(name, name_len, &pos->bid, machine->pid,
 370                                    in_kernel ? kmisc : umisc, fd);
 371                if (err)
 372                        break;
 373        }
 374
 375        return err;
 376}
 377
 378int perf_session__write_buildid_table(struct perf_session *session,
 379                                      struct feat_fd *fd)
 380{
 381        struct rb_node *nd;
 382        int err = machine__write_buildid_table(&session->machines.host, fd);
 383
 384        if (err)
 385                return err;
 386
 387        for (nd = rb_first_cached(&session->machines.guests); nd;
 388             nd = rb_next(nd)) {
 389                struct machine *pos = rb_entry(nd, struct machine, rb_node);
 390                err = machine__write_buildid_table(pos, fd);
 391                if (err)
 392                        break;
 393        }
 394        return err;
 395}
 396
 397static int __dsos__hit_all(struct list_head *head)
 398{
 399        struct dso *pos;
 400
 401        list_for_each_entry(pos, head, node)
 402                pos->hit = true;
 403
 404        return 0;
 405}
 406
 407static int machine__hit_all_dsos(struct machine *machine)
 408{
 409        return __dsos__hit_all(&machine->dsos.head);
 410}
 411
 412int dsos__hit_all(struct perf_session *session)
 413{
 414        struct rb_node *nd;
 415        int err;
 416
 417        err = machine__hit_all_dsos(&session->machines.host);
 418        if (err)
 419                return err;
 420
 421        for (nd = rb_first_cached(&session->machines.guests); nd;
 422             nd = rb_next(nd)) {
 423                struct machine *pos = rb_entry(nd, struct machine, rb_node);
 424
 425                err = machine__hit_all_dsos(pos);
 426                if (err)
 427                        return err;
 428        }
 429
 430        return 0;
 431}
 432
 433void disable_buildid_cache(void)
 434{
 435        no_buildid_cache = true;
 436}
 437
 438static bool lsdir_bid_head_filter(const char *name __maybe_unused,
 439                                  struct dirent *d)
 440{
 441        return (strlen(d->d_name) == 2) &&
 442                isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
 443}
 444
 445static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
 446                                  struct dirent *d)
 447{
 448        int i = 0;
 449        while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
 450                i++;
 451        return (i >= SBUILD_ID_MIN_SIZE - 3) && (i <= SBUILD_ID_SIZE - 3) &&
 452                (d->d_name[i] == '\0');
 453}
 454
 455struct strlist *build_id_cache__list_all(bool validonly)
 456{
 457        struct strlist *toplist, *linklist = NULL, *bidlist;
 458        struct str_node *nd, *nd2;
 459        char *topdir, *linkdir = NULL;
 460        char sbuild_id[SBUILD_ID_SIZE];
 461
 462        /* for filename__ functions */
 463        if (validonly)
 464                symbol__init(NULL);
 465
 466        /* Open the top-level directory */
 467        if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
 468                return NULL;
 469
 470        bidlist = strlist__new(NULL, NULL);
 471        if (!bidlist)
 472                goto out;
 473
 474        toplist = lsdir(topdir, lsdir_bid_head_filter);
 475        if (!toplist) {
 476                pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
 477                /* If there is no buildid cache, return an empty list */
 478                if (errno == ENOENT)
 479                        goto out;
 480                goto err_out;
 481        }
 482
 483        strlist__for_each_entry(nd, toplist) {
 484                if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
 485                        goto err_out;
 486                /* Open the lower-level directory */
 487                linklist = lsdir(linkdir, lsdir_bid_tail_filter);
 488                if (!linklist) {
 489                        pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
 490                        goto err_out;
 491                }
 492                strlist__for_each_entry(nd2, linklist) {
 493                        if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
 494                                     nd->s, nd2->s) > SBUILD_ID_SIZE - 1)
 495                                goto err_out;
 496                        if (validonly && !build_id_cache__valid_id(sbuild_id))
 497                                continue;
 498                        if (strlist__add(bidlist, sbuild_id) < 0)
 499                                goto err_out;
 500                }
 501                strlist__delete(linklist);
 502                zfree(&linkdir);
 503        }
 504
 505out_free:
 506        strlist__delete(toplist);
 507out:
 508        free(topdir);
 509
 510        return bidlist;
 511
 512err_out:
 513        strlist__delete(linklist);
 514        zfree(&linkdir);
 515        strlist__delete(bidlist);
 516        bidlist = NULL;
 517        goto out_free;
 518}
 519
 520static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
 521{
 522        size_t i;
 523
 524        for (i = 0; i < len; i++) {
 525                if (!isxdigit(maybe_sbuild_id[i]))
 526                        return false;
 527        }
 528        return true;
 529}
 530
 531/* Return the valid complete build-id */
 532char *build_id_cache__complement(const char *incomplete_sbuild_id)
 533{
 534        struct strlist *bidlist;
 535        struct str_node *nd, *cand = NULL;
 536        char *sbuild_id = NULL;
 537        size_t len = strlen(incomplete_sbuild_id);
 538
 539        if (len >= SBUILD_ID_SIZE ||
 540            !str_is_build_id(incomplete_sbuild_id, len))
 541                return NULL;
 542
 543        bidlist = build_id_cache__list_all(true);
 544        if (!bidlist)
 545                return NULL;
 546
 547        strlist__for_each_entry(nd, bidlist) {
 548                if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
 549                        continue;
 550                if (cand) {     /* Error: There are more than 2 candidates. */
 551                        cand = NULL;
 552                        break;
 553                }
 554                cand = nd;
 555        }
 556        if (cand)
 557                sbuild_id = strdup(cand->s);
 558        strlist__delete(bidlist);
 559
 560        return sbuild_id;
 561}
 562
 563char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
 564                               struct nsinfo *nsi, bool is_kallsyms,
 565                               bool is_vdso)
 566{
 567        char *realname = (char *)name, *filename;
 568        bool slash = is_kallsyms || is_vdso;
 569
 570        if (!slash) {
 571                realname = nsinfo__realpath(name, nsi);
 572                if (!realname)
 573                        return NULL;
 574        }
 575
 576        if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
 577                     is_vdso ? DSO__NAME_VDSO : realname,
 578                     sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
 579                filename = NULL;
 580
 581        if (!slash)
 582                free(realname);
 583
 584        return filename;
 585}
 586
 587int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi,
 588                                   struct strlist **result)
 589{
 590        char *dir_name;
 591        int ret = 0;
 592
 593        dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false);
 594        if (!dir_name)
 595                return -ENOMEM;
 596
 597        *result = lsdir(dir_name, lsdir_no_dot_filter);
 598        if (!*result)
 599                ret = -errno;
 600        free(dir_name);
 601
 602        return ret;
 603}
 604
 605#if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT)
 606static int build_id_cache__add_sdt_cache(const char *sbuild_id,
 607                                          const char *realname,
 608                                          struct nsinfo *nsi)
 609{
 610        struct probe_cache *cache;
 611        int ret;
 612        struct nscookie nsc;
 613
 614        cache = probe_cache__new(sbuild_id, nsi);
 615        if (!cache)
 616                return -1;
 617
 618        nsinfo__mountns_enter(nsi, &nsc);
 619        ret = probe_cache__scan_sdt(cache, realname);
 620        nsinfo__mountns_exit(&nsc);
 621        if (ret >= 0) {
 622                pr_debug4("Found %d SDTs in %s\n", ret, realname);
 623                if (probe_cache__commit(cache) < 0)
 624                        ret = -1;
 625        }
 626        probe_cache__delete(cache);
 627        return ret;
 628}
 629#else
 630#define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0)
 631#endif
 632
 633static char *build_id_cache__find_debug(const char *sbuild_id,
 634                                        struct nsinfo *nsi)
 635{
 636        char *realname = NULL;
 637        char *debugfile;
 638        struct nscookie nsc;
 639        size_t len = 0;
 640
 641        debugfile = calloc(1, PATH_MAX);
 642        if (!debugfile)
 643                goto out;
 644
 645        len = __symbol__join_symfs(debugfile, PATH_MAX,
 646                                   "/usr/lib/debug/.build-id/");
 647        snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id,
 648                 sbuild_id + 2);
 649
 650        nsinfo__mountns_enter(nsi, &nsc);
 651        realname = realpath(debugfile, NULL);
 652        if (realname && access(realname, R_OK))
 653                zfree(&realname);
 654        nsinfo__mountns_exit(&nsc);
 655
 656#ifdef HAVE_DEBUGINFOD_SUPPORT
 657        if (realname == NULL) {
 658                debuginfod_client* c = debuginfod_begin();
 659                if (c != NULL) {
 660                        int fd = debuginfod_find_debuginfo(c,
 661                                                           (const unsigned char*)sbuild_id, 0,
 662                                                           &realname);
 663                        if (fd >= 0)
 664                                close(fd); /* retaining reference by realname */
 665                        debuginfod_end(c);
 666                }
 667        }
 668#endif
 669
 670out:
 671        free(debugfile);
 672        return realname;
 673}
 674
 675int
 676build_id_cache__add(const char *sbuild_id, const char *name, const char *realname,
 677                    struct nsinfo *nsi, bool is_kallsyms, bool is_vdso)
 678{
 679        const size_t size = PATH_MAX;
 680        char *filename = NULL, *dir_name = NULL, *linkname = zalloc(size), *tmp;
 681        char *debugfile = NULL;
 682        int err = -1;
 683
 684        dir_name = build_id_cache__cachedir(sbuild_id, name, nsi, is_kallsyms,
 685                                            is_vdso);
 686        if (!dir_name)
 687                goto out_free;
 688
 689        /* Remove old style build-id cache */
 690        if (is_regular_file(dir_name))
 691                if (unlink(dir_name))
 692                        goto out_free;
 693
 694        if (mkdir_p(dir_name, 0755))
 695                goto out_free;
 696
 697        /* Save the allocated buildid dirname */
 698        if (asprintf(&filename, "%s/%s", dir_name,
 699                     build_id_cache__basename(is_kallsyms, is_vdso,
 700                     false)) < 0) {
 701                filename = NULL;
 702                goto out_free;
 703        }
 704
 705        if (access(filename, F_OK)) {
 706                if (is_kallsyms) {
 707                        if (copyfile("/proc/kallsyms", filename))
 708                                goto out_free;
 709                } else if (nsi && nsi->need_setns) {
 710                        if (copyfile_ns(name, filename, nsi))
 711                                goto out_free;
 712                } else if (link(realname, filename) && errno != EEXIST &&
 713                                copyfile(name, filename))
 714                        goto out_free;
 715        }
 716
 717        /* Some binaries are stripped, but have .debug files with their symbol
 718         * table.  Check to see if we can locate one of those, since the elf
 719         * file itself may not be very useful to users of our tools without a
 720         * symtab.
 721         */
 722        if (!is_kallsyms && !is_vdso &&
 723            strncmp(".ko", name + strlen(name) - 3, 3)) {
 724                debugfile = build_id_cache__find_debug(sbuild_id, nsi);
 725                if (debugfile) {
 726                        zfree(&filename);
 727                        if (asprintf(&filename, "%s/%s", dir_name,
 728                            build_id_cache__basename(false, false, true)) < 0) {
 729                                filename = NULL;
 730                                goto out_free;
 731                        }
 732                        if (access(filename, F_OK)) {
 733                                if (nsi && nsi->need_setns) {
 734                                        if (copyfile_ns(debugfile, filename,
 735                                                        nsi))
 736                                                goto out_free;
 737                                } else if (link(debugfile, filename) &&
 738                                                errno != EEXIST &&
 739                                                copyfile(debugfile, filename))
 740                                        goto out_free;
 741                        }
 742                }
 743        }
 744
 745        if (!build_id_cache__linkname(sbuild_id, linkname, size))
 746                goto out_free;
 747        tmp = strrchr(linkname, '/');
 748        *tmp = '\0';
 749
 750        if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 751                goto out_free;
 752
 753        *tmp = '/';
 754        tmp = dir_name + strlen(buildid_dir) - 5;
 755        memcpy(tmp, "../..", 5);
 756
 757        if (symlink(tmp, linkname) == 0) {
 758                err = 0;
 759        } else if (errno == EEXIST) {
 760                char path[PATH_MAX];
 761                ssize_t len;
 762
 763                len = readlink(linkname, path, sizeof(path) - 1);
 764                if (len <= 0) {
 765                        pr_err("Cant read link: %s\n", linkname);
 766                        goto out_free;
 767                }
 768                path[len] = '\0';
 769
 770                if (strcmp(tmp, path)) {
 771                        pr_debug("build <%s> already linked to %s\n",
 772                                 sbuild_id, linkname);
 773                }
 774                err = 0;
 775        }
 776
 777        /* Update SDT cache : error is just warned */
 778        if (realname &&
 779            build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0)
 780                pr_debug4("Failed to update/scan SDT cache for %s\n", realname);
 781
 782out_free:
 783        free(filename);
 784        free(debugfile);
 785        free(dir_name);
 786        free(linkname);
 787        return err;
 788}
 789
 790int build_id_cache__add_s(const char *sbuild_id, const char *name,
 791                          struct nsinfo *nsi, bool is_kallsyms, bool is_vdso)
 792{
 793        char *realname = NULL;
 794        int err = -1;
 795
 796        if (!is_kallsyms) {
 797                if (!is_vdso)
 798                        realname = nsinfo__realpath(name, nsi);
 799                else
 800                        realname = realpath(name, NULL);
 801                if (!realname)
 802                        goto out_free;
 803        }
 804
 805        err = build_id_cache__add(sbuild_id, name, realname, nsi, is_kallsyms, is_vdso);
 806
 807out_free:
 808        if (!is_kallsyms)
 809                free(realname);
 810        return err;
 811}
 812
 813static int build_id_cache__add_b(const struct build_id *bid,
 814                                 const char *name, struct nsinfo *nsi,
 815                                 bool is_kallsyms, bool is_vdso)
 816{
 817        char sbuild_id[SBUILD_ID_SIZE];
 818
 819        build_id__sprintf(bid, sbuild_id);
 820
 821        return build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms,
 822                                     is_vdso);
 823}
 824
 825bool build_id_cache__cached(const char *sbuild_id)
 826{
 827        bool ret = false;
 828        char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
 829
 830        if (filename && !access(filename, F_OK))
 831                ret = true;
 832        free(filename);
 833
 834        return ret;
 835}
 836
 837int build_id_cache__remove_s(const char *sbuild_id)
 838{
 839        const size_t size = PATH_MAX;
 840        char *filename = zalloc(size),
 841             *linkname = zalloc(size), *tmp;
 842        int err = -1;
 843
 844        if (filename == NULL || linkname == NULL)
 845                goto out_free;
 846
 847        if (!build_id_cache__linkname(sbuild_id, linkname, size))
 848                goto out_free;
 849
 850        if (access(linkname, F_OK))
 851                goto out_free;
 852
 853        if (readlink(linkname, filename, size - 1) < 0)
 854                goto out_free;
 855
 856        if (unlink(linkname))
 857                goto out_free;
 858
 859        /*
 860         * Since the link is relative, we must make it absolute:
 861         */
 862        tmp = strrchr(linkname, '/') + 1;
 863        snprintf(tmp, size - (tmp - linkname), "%s", filename);
 864
 865        if (rm_rf(linkname))
 866                goto out_free;
 867
 868        err = 0;
 869out_free:
 870        free(filename);
 871        free(linkname);
 872        return err;
 873}
 874
 875static int dso__cache_build_id(struct dso *dso, struct machine *machine,
 876                               void *priv __maybe_unused)
 877{
 878        bool is_kallsyms = dso__is_kallsyms(dso);
 879        bool is_vdso = dso__is_vdso(dso);
 880        const char *name = dso->long_name;
 881
 882        if (!dso->has_build_id)
 883                return 0;
 884
 885        if (dso__is_kcore(dso)) {
 886                is_kallsyms = true;
 887                name = machine->mmap_name;
 888        }
 889        return build_id_cache__add_b(&dso->bid, name, dso->nsinfo,
 890                                     is_kallsyms, is_vdso);
 891}
 892
 893static int
 894machines__for_each_dso(struct machines *machines, machine__dso_t fn, void *priv)
 895{
 896        int ret = machine__for_each_dso(&machines->host, fn, priv);
 897        struct rb_node *nd;
 898
 899        for (nd = rb_first_cached(&machines->guests); nd;
 900             nd = rb_next(nd)) {
 901                struct machine *pos = rb_entry(nd, struct machine, rb_node);
 902
 903                ret |= machine__for_each_dso(pos, fn, priv);
 904        }
 905        return ret ? -1 : 0;
 906}
 907
 908int __perf_session__cache_build_ids(struct perf_session *session,
 909                                    machine__dso_t fn, void *priv)
 910{
 911        if (no_buildid_cache)
 912                return 0;
 913
 914        if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 915                return -1;
 916
 917        return machines__for_each_dso(&session->machines, fn, priv) ?  -1 : 0;
 918}
 919
 920int perf_session__cache_build_ids(struct perf_session *session)
 921{
 922        return __perf_session__cache_build_ids(session, dso__cache_build_id, NULL);
 923}
 924
 925static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 926{
 927        return __dsos__read_build_ids(&machine->dsos.head, with_hits);
 928}
 929
 930bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 931{
 932        struct rb_node *nd;
 933        bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 934
 935        for (nd = rb_first_cached(&session->machines.guests); nd;
 936             nd = rb_next(nd)) {
 937                struct machine *pos = rb_entry(nd, struct machine, rb_node);
 938                ret |= machine__read_build_ids(pos, with_hits);
 939        }
 940
 941        return ret;
 942}
 943
 944void build_id__init(struct build_id *bid, const u8 *data, size_t size)
 945{
 946        WARN_ON(size > BUILD_ID_SIZE);
 947        memcpy(bid->data, data, size);
 948        bid->size = size;
 949}
 950
 951bool build_id__is_defined(const struct build_id *bid)
 952{
 953        return bid && bid->size ? !!memchr_inv(bid->data, 0, bid->size) : false;
 954}
 955