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