tools/perf/util/build-id.c

   1 /*
   2  * build-id.c
   3  *
   4  * build-id support
   5  *
   6  * Copyright (C) 2009, 2010 Red Hat Inc.
   7  * Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
   8  */
   9 #include "util.h"
  10 #include <stdio.h>
  11 #include "build-id.h"
  12 #include "event.h"
  13 #include "symbol.h"
  14 #include <linux/kernel.h>
  15 #include "debug.h"
  16 #include "session.h"
  17 #include "tool.h"
  18 #include "header.h"
  19 #include "vdso.h"
  20
  21
  22 static bool no_buildid_cache;
  23
  24 int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
  25                            union perf_event *event,
  26                            struct perf_sample *sample,
  27                            struct perf_evsel *evsel __maybe_unused,
  28                            struct machine *machine)
  29 {
  30         struct addr_location al;
  31         struct thread *thread = machine__findnew_thread(machine, sample->pid,
  32                                                         sample->tid);
  33
  34         if (thread == NULL) {
  35                 pr_err("problem processing %d event, skipping it.\n",
  36                         event->header.type);
  37                 return -1;
  38         }
  39
  40         thread__find_addr_map(thread, sample->cpumode, MAP__FUNCTION, sample->ip, &al);
  41
  42         if (al.map != NULL)
  43                 al.map->dso->hit = 1;
  44
  45         thread__put(thread);
  46         return 0;
  47 }
  48
  49 static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
  50                                        union perf_event *event,
  51                                        struct perf_sample *sample
  52                                        __maybe_unused,
  53                                        struct machine *machine)
  54 {
  55         struct thread *thread = machine__findnew_thread(machine,
  56                                                         event->fork.pid,
  57                                                         event->fork.tid);
  58
  59         dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
  60                     event->fork.ppid, event->fork.ptid);
  61
  62         if (thread) {
  63                 machine__remove_thread(machine, thread);
  64                 thread__put(thread);
  65         }
  66
  67         return 0;
  68 }
  69
  70 struct perf_tool build_id__mark_dso_hit_ops = {
  71         .sample = build_id__mark_dso_hit,
  72         .mmap   = perf_event__process_mmap,
  73         .mmap2  = perf_event__process_mmap2,
  74         .fork   = perf_event__process_fork,
  75         .exit   = perf_event__exit_del_thread,
  76         .attr            = perf_event__process_attr,
  77         .build_id        = perf_event__process_build_id,
  78         .ordered_events  = true,
  79 };
  80
  81 int build_id__sprintf(const u8 *build_id, int len, char *bf)
  82 {
  83         char *bid = bf;
  84         const u8 *raw = build_id;
  85         int i;
  86
  87         for (i = 0; i < len; ++i) {
  88                 sprintf(bid, "%02x", *raw);
  89                 ++raw;
  90                 bid += 2;
  91         }
  92
  93         return (bid - bf) + 1;
  94 }
  95
  96 int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
  97 {
  98         char notes[PATH_MAX];
  99         u8 build_id[BUILD_ID_SIZE];
 100         int ret;
 101
 102         if (!root_dir)
 103                 root_dir = "";
 104
 105         scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
 106
 107         ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
 108         if (ret < 0)
 109                 return ret;
 110
 111         return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
 112 }
 113
 114 int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
 115 {
 116         u8 build_id[BUILD_ID_SIZE];
 117         int ret;
 118
 119         ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
 120         if (ret < 0)
 121                 return ret;
 122         else if (ret != sizeof(build_id))
 123                 return -EINVAL;
 124
 125         return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
 126 }
 127
 128 /* asnprintf consolidates asprintf and snprintf */
 129 static int asnprintf(char **strp, size_t size, const char *fmt, ...)
 130 {
 131         va_list ap;
 132         int ret;
 133
 134         if (!strp)
 135                 return -EINVAL;
 136
 137         va_start(ap, fmt);
 138         if (*strp)
 139                 ret = vsnprintf(*strp, size, fmt, ap);
 140         else
 141                 ret = vasprintf(strp, fmt, ap);
 142         va_end(ap);
 143
 144         return ret;
 145 }
 146
 147 char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
 148                                     size_t size)
 149 {
 150         bool retry_old = true;
 151
 152         snprintf(bf, size, "%s/%s/%s/kallsyms",
 153                  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 154 retry:
 155         if (!access(bf, F_OK))
 156                 return bf;
 157         if (retry_old) {
 158                 /* Try old style kallsyms cache */
 159                 snprintf(bf, size, "%s/%s/%s",
 160                          buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 161                 retry_old = false;
 162                 goto retry;
 163         }
 164
 165         return NULL;
 166 }
 167
 168 static char *build_id_cache__linkname(const char *sbuild_id, char *bf,
 169                                       size_t size)
 170 {
 171         char *tmp = bf;
 172         int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
 173                             sbuild_id, sbuild_id + 2);
 174         if (ret < 0 || (tmp && size < (unsigned int)ret))
 175                 return NULL;
 176         return bf;
 177 }
 178
 179 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso)
 180 {
 181         return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : "elf");
 182 }
 183
 184 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
 185 {
 186         bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
 187         bool is_vdso = dso__is_vdso((struct dso *)dso);
 188         char sbuild_id[SBUILD_ID_SIZE];
 189         char *linkname;
 190         bool alloc = (bf == NULL);
 191         int ret;
 192
 193         if (!dso->has_build_id)
 194                 return NULL;
 195
 196         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 197         linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
 198         if (!linkname)
 199                 return NULL;
 200
 201         /* Check if old style build_id cache */
 202         if (is_regular_file(linkname))
 203                 ret = asnprintf(&bf, size, "%s", linkname);
 204         else
 205                 ret = asnprintf(&bf, size, "%s/%s", linkname,
 206                          build_id_cache__basename(is_kallsyms, is_vdso));
 207         if (ret < 0 || (!alloc && size < (unsigned int)ret))
 208                 bf = NULL;
 209         free(linkname);
 210
 211         return bf;
 212 }
 213
 214 bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size)
 215 {
 216         char *id_name = NULL, *ch;
 217         struct stat sb;
 218         char sbuild_id[SBUILD_ID_SIZE];
 219
 220         if (!dso->has_build_id)
 221                 goto err;
 222
 223         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 224         id_name = build_id_cache__linkname(sbuild_id, NULL, 0);
 225         if (!id_name)
 226                 goto err;
 227         if (access(id_name, F_OK))
 228                 goto err;
 229         if (lstat(id_name, &sb) == -1)
 230                 goto err;
 231         if ((size_t)sb.st_size > size - 1)
 232                 goto err;
 233         if (readlink(id_name, bf, size - 1) < 0)
 234                 goto err;
 235
 236         bf[sb.st_size] = '\0';
 237
 238         /*
 239          * link should be:
 240          * ../../lib/modules/4.4.0-rc4/kernel/net/ipv4/netfilter/nf_nat_ipv4.ko/a09fe3eb3147dafa4e3b31dbd6257e4d696bdc92
 241          */
 242         ch = strrchr(bf, '/');
 243         if (!ch)
 244                 goto err;
 245         if (ch - 3 < bf)
 246                 goto err;
 247
 248         free(id_name);
 249         return strncmp(".ko", ch - 3, 3) == 0;
 250 err:
 251         pr_err("Invalid build id: %s\n", id_name ? :
 252                                          dso->long_name ? :
 253                                          dso->short_name ? :
 254                                          "[unknown]");
 255         free(id_name);
 256         return false;
 257 }
 258
 259 #define dsos__for_each_with_build_id(pos, head) \
 260         list_for_each_entry(pos, head, node)    \
 261                 if (!pos->has_build_id)         \
 262                         continue;               \
 263                 else
 264
 265 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 266                          pid_t pid, u16 misc, int fd)
 267 {
 268         int err;
 269         struct build_id_event b;
 270         size_t len;
 271
 272         len = name_len + 1;
 273         len = PERF_ALIGN(len, NAME_ALIGN);
 274
 275         memset(&b, 0, sizeof(b));
 276         memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
 277         b.pid = pid;
 278         b.header.misc = misc;
 279         b.header.size = sizeof(b) + len;
 280
 281         err = writen(fd, &b, sizeof(b));
 282         if (err < 0)
 283                 return err;
 284
 285         return write_padded(fd, name, name_len + 1, len);
 286 }
 287
 288 static int machine__write_buildid_table(struct machine *machine, int fd)
 289 {
 290         int err = 0;
 291         char nm[PATH_MAX];
 292         struct dso *pos;
 293         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 294             umisc = PERF_RECORD_MISC_USER;
 295
 296         if (!machine__is_host(machine)) {
 297                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 298                 umisc = PERF_RECORD_MISC_GUEST_USER;
 299         }
 300
 301         dsos__for_each_with_build_id(pos, &machine->dsos.head) {
 302                 const char *name;
 303                 size_t name_len;
 304                 bool in_kernel = false;
 305
 306                 if (!pos->hit && !dso__is_vdso(pos))
 307                         continue;
 308
 309                 if (dso__is_vdso(pos)) {
 310                         name = pos->short_name;
 311                         name_len = pos->short_name_len;
 312                 } else if (dso__is_kcore(pos)) {
 313                         machine__mmap_name(machine, nm, sizeof(nm));
 314                         name = nm;
 315                         name_len = strlen(nm);
 316                 } else {
 317                         name = pos->long_name;
 318                         name_len = pos->long_name_len;
 319                 }
 320
 321                 in_kernel = pos->kernel ||
 322                                 is_kernel_module(name,
 323                                         PERF_RECORD_MISC_CPUMODE_UNKNOWN);
 324                 err = write_buildid(name, name_len, pos->build_id, machine->pid,
 325                                     in_kernel ? kmisc : umisc, fd);
 326                 if (err)
 327                         break;
 328         }
 329
 330         return err;
 331 }
 332
 333 int perf_session__write_buildid_table(struct perf_session *session, int fd)
 334 {
 335         struct rb_node *nd;
 336         int err = machine__write_buildid_table(&session->machines.host, fd);
 337
 338         if (err)
 339                 return err;
 340
 341         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 342                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 343                 err = machine__write_buildid_table(pos, fd);
 344                 if (err)
 345                         break;
 346         }
 347         return err;
 348 }
 349
 350 static int __dsos__hit_all(struct list_head *head)
 351 {
 352         struct dso *pos;
 353
 354         list_for_each_entry(pos, head, node)
 355                 pos->hit = true;
 356
 357         return 0;
 358 }
 359
 360 static int machine__hit_all_dsos(struct machine *machine)
 361 {
 362         return __dsos__hit_all(&machine->dsos.head);
 363 }
 364
 365 int dsos__hit_all(struct perf_session *session)
 366 {
 367         struct rb_node *nd;
 368         int err;
 369
 370         err = machine__hit_all_dsos(&session->machines.host);
 371         if (err)
 372                 return err;
 373
 374         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 375                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 376
 377                 err = machine__hit_all_dsos(pos);
 378                 if (err)
 379                         return err;
 380         }
 381
 382         return 0;
 383 }
 384
 385 void disable_buildid_cache(void)
 386 {
 387         no_buildid_cache = true;
 388 }
 389
 390 static char *build_id_cache__dirname_from_path(const char *name,
 391                                                bool is_kallsyms, bool is_vdso,
 392                                                const char *sbuild_id)
 393 {
 394         char *realname = (char *)name, *filename;
 395         bool slash = is_kallsyms || is_vdso;
 396
 397         if (!slash) {
 398                 realname = realpath(name, NULL);
 399                 if (!realname)
 400                         return NULL;
 401         }
 402
 403         if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
 404                      is_vdso ? DSO__NAME_VDSO : realname,
 405                      sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
 406                 filename = NULL;
 407
 408         if (!slash)
 409                 free(realname);
 410
 411         return filename;
 412 }
 413
 414 int build_id_cache__list_build_ids(const char *pathname,
 415                                    struct strlist **result)
 416 {
 417         char *dir_name;
 418         int ret = 0;
 419
 420         dir_name = build_id_cache__dirname_from_path(pathname, false, false,
 421                                                      NULL);
 422         if (!dir_name)
 423                 return -ENOMEM;
 424
 425         *result = lsdir(dir_name, lsdir_no_dot_filter);
 426         if (!*result)
 427                 ret = -errno;
 428         free(dir_name);
 429
 430         return ret;
 431 }
 432
 433 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 434                           bool is_kallsyms, bool is_vdso)
 435 {
 436         const size_t size = PATH_MAX;
 437         char *realname = NULL, *filename = NULL, *dir_name = NULL,
 438              *linkname = zalloc(size), *tmp;
 439         int err = -1;
 440
 441         if (!is_kallsyms) {
 442                 realname = realpath(name, NULL);
 443                 if (!realname)
 444                         goto out_free;
 445         }
 446
 447         dir_name = build_id_cache__dirname_from_path(name, is_kallsyms,
 448                                                      is_vdso, sbuild_id);
 449         if (!dir_name)
 450                 goto out_free;
 451
 452         /* Remove old style build-id cache */
 453         if (is_regular_file(dir_name))
 454                 if (unlink(dir_name))
 455                         goto out_free;
 456
 457         if (mkdir_p(dir_name, 0755))
 458                 goto out_free;
 459
 460         /* Save the allocated buildid dirname */
 461         if (asprintf(&filename, "%s/%s", dir_name,
 462                      build_id_cache__basename(is_kallsyms, is_vdso)) < 0) {
 463                 filename = NULL;
 464                 goto out_free;
 465         }
 466
 467         if (access(filename, F_OK)) {
 468                 if (is_kallsyms) {
 469                          if (copyfile("/proc/kallsyms", filename))
 470                                 goto out_free;
 471                 } else if (link(realname, filename) && errno != EEXIST &&
 472                                 copyfile(name, filename))
 473                         goto out_free;
 474         }
 475
 476         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 477                 goto out_free;
 478         tmp = strrchr(linkname, '/');
 479         *tmp = '\0';
 480
 481         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 482                 goto out_free;
 483
 484         *tmp = '/';
 485         tmp = dir_name + strlen(buildid_dir) - 5;
 486         memcpy(tmp, "../..", 5);
 487
 488         if (symlink(tmp, linkname) == 0)
 489                 err = 0;
 490 out_free:
 491         if (!is_kallsyms)
 492                 free(realname);
 493         free(filename);
 494         free(dir_name);
 495         free(linkname);
 496         return err;
 497 }
 498
 499 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 500                                  const char *name, bool is_kallsyms,
 501                                  bool is_vdso)
 502 {
 503         char sbuild_id[SBUILD_ID_SIZE];
 504
 505         build_id__sprintf(build_id, build_id_size, sbuild_id);
 506
 507         return build_id_cache__add_s(sbuild_id, name, is_kallsyms, is_vdso);
 508 }
 509
 510 bool build_id_cache__cached(const char *sbuild_id)
 511 {
 512         bool ret = false;
 513         char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
 514
 515         if (filename && !access(filename, F_OK))
 516                 ret = true;
 517         free(filename);
 518
 519         return ret;
 520 }
 521
 522 int build_id_cache__remove_s(const char *sbuild_id)
 523 {
 524         const size_t size = PATH_MAX;
 525         char *filename = zalloc(size),
 526              *linkname = zalloc(size), *tmp;
 527         int err = -1;
 528
 529         if (filename == NULL || linkname == NULL)
 530                 goto out_free;
 531
 532         if (!build_id_cache__linkname(sbuild_id, linkname, size))
 533                 goto out_free;
 534
 535         if (access(linkname, F_OK))
 536                 goto out_free;
 537
 538         if (readlink(linkname, filename, size - 1) < 0)
 539                 goto out_free;
 540
 541         if (unlink(linkname))
 542                 goto out_free;
 543
 544         /*
 545          * Since the link is relative, we must make it absolute:
 546          */
 547         tmp = strrchr(linkname, '/') + 1;
 548         snprintf(tmp, size - (tmp - linkname), "%s", filename);
 549
 550         if (rm_rf(linkname))
 551                 goto out_free;
 552
 553         err = 0;
 554 out_free:
 555         free(filename);
 556         free(linkname);
 557         return err;
 558 }
 559
 560 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 561 {
 562         bool is_kallsyms = dso__is_kallsyms(dso);
 563         bool is_vdso = dso__is_vdso(dso);
 564         const char *name = dso->long_name;
 565         char nm[PATH_MAX];
 566
 567         if (dso__is_kcore(dso)) {
 568                 is_kallsyms = true;
 569                 machine__mmap_name(machine, nm, sizeof(nm));
 570                 name = nm;
 571         }
 572         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 573                                      is_kallsyms, is_vdso);
 574 }
 575
 576 static int __dsos__cache_build_ids(struct list_head *head,
 577                                    struct machine *machine)
 578 {
 579         struct dso *pos;
 580         int err = 0;
 581
 582         dsos__for_each_with_build_id(pos, head)
 583                 if (dso__cache_build_id(pos, machine))
 584                         err = -1;
 585
 586         return err;
 587 }
 588
 589 static int machine__cache_build_ids(struct machine *machine)
 590 {
 591         return __dsos__cache_build_ids(&machine->dsos.head, machine);
 592 }
 593
 594 int perf_session__cache_build_ids(struct perf_session *session)
 595 {
 596         struct rb_node *nd;
 597         int ret;
 598
 599         if (no_buildid_cache)
 600                 return 0;
 601
 602         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 603                 return -1;
 604
 605         ret = machine__cache_build_ids(&session->machines.host);
 606
 607         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 608                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 609                 ret |= machine__cache_build_ids(pos);
 610         }
 611         return ret ? -1 : 0;
 612 }
 613
 614 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 615 {
 616         return __dsos__read_build_ids(&machine->dsos.head, with_hits);
 617 }
 618
 619 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 620 {
 621         struct rb_node *nd;
 622         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 623
 624         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 625                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 626                 ret |= machine__read_build_ids(pos, with_hits);
 627         }
 628
 629         return ret;
 630 }