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