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