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