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 static char *build_id__filename(const char *sbuild_id, char *bf, size_t size)
 148 {
 149         char *tmp = bf;
 150         int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
 151                             sbuild_id, sbuild_id + 2);
 152         if (ret < 0 || (tmp && size < (unsigned int)ret))
 153                 return NULL;
 154         return bf;
 155 }
 156
 157 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
 158 {
 159         char build_id_hex[SBUILD_ID_SIZE];
 160
 161         if (!dso->has_build_id)
 162                 return NULL;
 163
 164         build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex);
 165         return build_id__filename(build_id_hex, bf, size);
 166 }
 167
 168 bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size)
 169 {
 170         char *id_name, *ch;
 171         struct stat sb;
 172
 173         id_name = dso__build_id_filename(dso, bf, size);
 174         if (!id_name)
 175                 goto err;
 176         if (access(id_name, F_OK))
 177                 goto err;
 178         if (lstat(id_name, &sb) == -1)
 179                 goto err;
 180         if ((size_t)sb.st_size > size - 1)
 181                 goto err;
 182         if (readlink(id_name, bf, size - 1) < 0)
 183                 goto err;
 184
 185         bf[sb.st_size] = '\0';
 186
 187         /*
 188          * link should be:
 189          * ../../lib/modules/4.4.0-rc4/kernel/net/ipv4/netfilter/nf_nat_ipv4.ko/a09fe3eb3147dafa4e3b31dbd6257e4d696bdc92
 190          */
 191         ch = strrchr(bf, '/');
 192         if (!ch)
 193                 goto err;
 194         if (ch - 3 < bf)
 195                 goto err;
 196
 197         return strncmp(".ko", ch - 3, 3) == 0;
 198 err:
 199         /*
 200          * If dso__build_id_filename work, get id_name again,
 201          * because id_name points to bf and is broken.
 202          */
 203         if (id_name)
 204                 id_name = dso__build_id_filename(dso, bf, size);
 205         pr_err("Invalid build id: %s\n", id_name ? :
 206                                          dso->long_name ? :
 207                                          dso->short_name ? :
 208                                          "[unknown]");
 209         return false;
 210 }
 211
 212 #define dsos__for_each_with_build_id(pos, head) \
 213         list_for_each_entry(pos, head, node)    \
 214                 if (!pos->has_build_id)         \
 215                         continue;               \
 216                 else
 217
 218 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 219                          pid_t pid, u16 misc, int fd)
 220 {
 221         int err;
 222         struct build_id_event b;
 223         size_t len;
 224
 225         len = name_len + 1;
 226         len = PERF_ALIGN(len, NAME_ALIGN);
 227
 228         memset(&b, 0, sizeof(b));
 229         memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
 230         b.pid = pid;
 231         b.header.misc = misc;
 232         b.header.size = sizeof(b) + len;
 233
 234         err = writen(fd, &b, sizeof(b));
 235         if (err < 0)
 236                 return err;
 237
 238         return write_padded(fd, name, name_len + 1, len);
 239 }
 240
 241 static int machine__write_buildid_table(struct machine *machine, int fd)
 242 {
 243         int err = 0;
 244         char nm[PATH_MAX];
 245         struct dso *pos;
 246         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 247             umisc = PERF_RECORD_MISC_USER;
 248
 249         if (!machine__is_host(machine)) {
 250                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 251                 umisc = PERF_RECORD_MISC_GUEST_USER;
 252         }
 253
 254         dsos__for_each_with_build_id(pos, &machine->dsos.head) {
 255                 const char *name;
 256                 size_t name_len;
 257                 bool in_kernel = false;
 258
 259                 if (!pos->hit && !dso__is_vdso(pos))
 260                         continue;
 261
 262                 if (dso__is_vdso(pos)) {
 263                         name = pos->short_name;
 264                         name_len = pos->short_name_len;
 265                 } else if (dso__is_kcore(pos)) {
 266                         machine__mmap_name(machine, nm, sizeof(nm));
 267                         name = nm;
 268                         name_len = strlen(nm);
 269                 } else {
 270                         name = pos->long_name;
 271                         name_len = pos->long_name_len;
 272                 }
 273
 274                 in_kernel = pos->kernel ||
 275                                 is_kernel_module(name,
 276                                         PERF_RECORD_MISC_CPUMODE_UNKNOWN);
 277                 err = write_buildid(name, name_len, pos->build_id, machine->pid,
 278                                     in_kernel ? kmisc : umisc, fd);
 279                 if (err)
 280                         break;
 281         }
 282
 283         return err;
 284 }
 285
 286 int perf_session__write_buildid_table(struct perf_session *session, int fd)
 287 {
 288         struct rb_node *nd;
 289         int err = machine__write_buildid_table(&session->machines.host, fd);
 290
 291         if (err)
 292                 return err;
 293
 294         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 295                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 296                 err = machine__write_buildid_table(pos, fd);
 297                 if (err)
 298                         break;
 299         }
 300         return err;
 301 }
 302
 303 static int __dsos__hit_all(struct list_head *head)
 304 {
 305         struct dso *pos;
 306
 307         list_for_each_entry(pos, head, node)
 308                 pos->hit = true;
 309
 310         return 0;
 311 }
 312
 313 static int machine__hit_all_dsos(struct machine *machine)
 314 {
 315         return __dsos__hit_all(&machine->dsos.head);
 316 }
 317
 318 int dsos__hit_all(struct perf_session *session)
 319 {
 320         struct rb_node *nd;
 321         int err;
 322
 323         err = machine__hit_all_dsos(&session->machines.host);
 324         if (err)
 325                 return err;
 326
 327         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 328                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 329
 330                 err = machine__hit_all_dsos(pos);
 331                 if (err)
 332                         return err;
 333         }
 334
 335         return 0;
 336 }
 337
 338 void disable_buildid_cache(void)
 339 {
 340         no_buildid_cache = true;
 341 }
 342
 343 static char *build_id_cache__dirname_from_path(const char *name,
 344                                                bool is_kallsyms, bool is_vdso)
 345 {
 346         char *realname = (char *)name, *filename;
 347         bool slash = is_kallsyms || is_vdso;
 348
 349         if (!slash) {
 350                 realname = realpath(name, NULL);
 351                 if (!realname)
 352                         return NULL;
 353         }
 354
 355         if (asprintf(&filename, "%s%s%s", buildid_dir, slash ? "/" : "",
 356                      is_vdso ? DSO__NAME_VDSO : realname) < 0)
 357                 filename = NULL;
 358
 359         if (!slash)
 360                 free(realname);
 361
 362         return filename;
 363 }
 364
 365 int build_id_cache__list_build_ids(const char *pathname,
 366                                    struct strlist **result)
 367 {
 368         char *dir_name;
 369         int ret = 0;
 370
 371         dir_name = build_id_cache__dirname_from_path(pathname, false, false);
 372         if (!dir_name)
 373                 return -ENOMEM;
 374
 375         *result = lsdir(dir_name, lsdir_no_dot_filter);
 376         if (!*result)
 377                 ret = -errno;
 378         free(dir_name);
 379
 380         return ret;
 381 }
 382
 383 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 384                           bool is_kallsyms, bool is_vdso)
 385 {
 386         const size_t size = PATH_MAX;
 387         char *realname = NULL, *filename = NULL, *dir_name = NULL,
 388              *linkname = zalloc(size), *targetname, *tmp;
 389         int err = -1;
 390
 391         if (!is_kallsyms) {
 392                 realname = realpath(name, NULL);
 393                 if (!realname)
 394                         goto out_free;
 395         }
 396
 397         dir_name = build_id_cache__dirname_from_path(name, is_kallsyms, is_vdso);
 398         if (!dir_name)
 399                 goto out_free;
 400
 401         if (mkdir_p(dir_name, 0755))
 402                 goto out_free;
 403
 404         if (asprintf(&filename, "%s/%s", dir_name, sbuild_id) < 0) {
 405                 filename = NULL;
 406                 goto out_free;
 407         }
 408
 409         if (access(filename, F_OK)) {
 410                 if (is_kallsyms) {
 411                          if (copyfile("/proc/kallsyms", filename))
 412                                 goto out_free;
 413                 } else if (link(realname, filename) && errno != EEXIST &&
 414                                 copyfile(name, filename))
 415                         goto out_free;
 416         }
 417
 418         if (!build_id__filename(sbuild_id, linkname, size))
 419                 goto out_free;
 420         tmp = strrchr(linkname, '/');
 421         *tmp = '\0';
 422
 423         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 424                 goto out_free;
 425
 426         *tmp = '/';
 427         targetname = filename + strlen(buildid_dir) - 5;
 428         memcpy(targetname, "../..", 5);
 429
 430         if (symlink(targetname, linkname) == 0)
 431                 err = 0;
 432 out_free:
 433         if (!is_kallsyms)
 434                 free(realname);
 435         free(filename);
 436         free(dir_name);
 437         free(linkname);
 438         return err;
 439 }
 440
 441 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 442                                  const char *name, bool is_kallsyms,
 443                                  bool is_vdso)
 444 {
 445         char sbuild_id[SBUILD_ID_SIZE];
 446
 447         build_id__sprintf(build_id, build_id_size, sbuild_id);
 448
 449         return build_id_cache__add_s(sbuild_id, name, is_kallsyms, is_vdso);
 450 }
 451
 452 bool build_id_cache__cached(const char *sbuild_id)
 453 {
 454         bool ret = false;
 455         char *filename = build_id__filename(sbuild_id, NULL, 0);
 456
 457         if (filename && !access(filename, F_OK))
 458                 ret = true;
 459         free(filename);
 460
 461         return ret;
 462 }
 463
 464 int build_id_cache__remove_s(const char *sbuild_id)
 465 {
 466         const size_t size = PATH_MAX;
 467         char *filename = zalloc(size),
 468              *linkname = zalloc(size), *tmp;
 469         int err = -1;
 470
 471         if (filename == NULL || linkname == NULL)
 472                 goto out_free;
 473
 474         if (!build_id__filename(sbuild_id, linkname, size))
 475                 goto out_free;
 476
 477         if (access(linkname, F_OK))
 478                 goto out_free;
 479
 480         if (readlink(linkname, filename, size - 1) < 0)
 481                 goto out_free;
 482
 483         if (unlink(linkname))
 484                 goto out_free;
 485
 486         /*
 487          * Since the link is relative, we must make it absolute:
 488          */
 489         tmp = strrchr(linkname, '/') + 1;
 490         snprintf(tmp, size - (tmp - linkname), "%s", filename);
 491
 492         if (unlink(linkname))
 493                 goto out_free;
 494
 495         err = 0;
 496 out_free:
 497         free(filename);
 498         free(linkname);
 499         return err;
 500 }
 501
 502 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 503 {
 504         bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
 505         bool is_vdso = dso__is_vdso(dso);
 506         const char *name = dso->long_name;
 507         char nm[PATH_MAX];
 508
 509         if (dso__is_kcore(dso)) {
 510                 is_kallsyms = true;
 511                 machine__mmap_name(machine, nm, sizeof(nm));
 512                 name = nm;
 513         }
 514         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 515                                      is_kallsyms, is_vdso);
 516 }
 517
 518 static int __dsos__cache_build_ids(struct list_head *head,
 519                                    struct machine *machine)
 520 {
 521         struct dso *pos;
 522         int err = 0;
 523
 524         dsos__for_each_with_build_id(pos, head)
 525                 if (dso__cache_build_id(pos, machine))
 526                         err = -1;
 527
 528         return err;
 529 }
 530
 531 static int machine__cache_build_ids(struct machine *machine)
 532 {
 533         return __dsos__cache_build_ids(&machine->dsos.head, machine);
 534 }
 535
 536 int perf_session__cache_build_ids(struct perf_session *session)
 537 {
 538         struct rb_node *nd;
 539         int ret;
 540
 541         if (no_buildid_cache)
 542                 return 0;
 543
 544         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 545                 return -1;
 546
 547         ret = machine__cache_build_ids(&session->machines.host);
 548
 549         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 550                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 551                 ret |= machine__cache_build_ids(pos);
 552         }
 553         return ret ? -1 : 0;
 554 }
 555
 556 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 557 {
 558         return __dsos__read_build_ids(&machine->dsos.head, with_hits);
 559 }
 560
 561 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 562 {
 563         struct rb_node *nd;
 564         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 565
 566         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 567                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 568                 ret |= machine__read_build_ids(pos, with_hits);
 569         }
 570
 571         return ret;
 572 }