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 /* asnprintf consolidates asprintf and snprintf */
  97 static int asnprintf(char **strp, size_t size, const char *fmt, ...)
  98 {
  99         va_list ap;
 100         int ret;
 101
 102         if (!strp)
 103                 return -EINVAL;
 104
 105         va_start(ap, fmt);
 106         if (*strp)
 107                 ret = vsnprintf(*strp, size, fmt, ap);
 108         else
 109                 ret = vasprintf(strp, fmt, ap);
 110         va_end(ap);
 111
 112         return ret;
 113 }
 114
 115 static char *build_id__filename(const char *sbuild_id, char *bf, size_t size)
 116 {
 117         char *tmp = bf;
 118         int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
 119                             sbuild_id, sbuild_id + 2);
 120         if (ret < 0 || (tmp && size < (unsigned int)ret))
 121                 return NULL;
 122         return bf;
 123 }
 124
 125 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
 126 {
 127         char build_id_hex[BUILD_ID_SIZE * 2 + 1];
 128
 129         if (!dso->has_build_id)
 130                 return NULL;
 131
 132         build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex);
 133         return build_id__filename(build_id_hex, bf, size);
 134 }
 135
 136 #define dsos__for_each_with_build_id(pos, head) \
 137         list_for_each_entry(pos, head, node)    \
 138                 if (!pos->has_build_id)         \
 139                         continue;               \
 140                 else
 141
 142 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 143                          pid_t pid, u16 misc, int fd)
 144 {
 145         int err;
 146         struct build_id_event b;
 147         size_t len;
 148
 149         len = name_len + 1;
 150         len = PERF_ALIGN(len, NAME_ALIGN);
 151
 152         memset(&b, 0, sizeof(b));
 153         memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
 154         b.pid = pid;
 155         b.header.misc = misc;
 156         b.header.size = sizeof(b) + len;
 157
 158         err = writen(fd, &b, sizeof(b));
 159         if (err < 0)
 160                 return err;
 161
 162         return write_padded(fd, name, name_len + 1, len);
 163 }
 164
 165 static int __dsos__write_buildid_table(struct list_head *head,
 166                                        struct machine *machine,
 167                                        pid_t pid, u16 misc, int fd)
 168 {
 169         char nm[PATH_MAX];
 170         struct dso *pos;
 171
 172         dsos__for_each_with_build_id(pos, head) {
 173                 int err;
 174                 const char *name;
 175                 size_t name_len;
 176
 177                 if (!pos->hit)
 178                         continue;
 179
 180                 if (dso__is_vdso(pos)) {
 181                         name = pos->short_name;
 182                         name_len = pos->short_name_len + 1;
 183                 } else if (dso__is_kcore(pos)) {
 184                         machine__mmap_name(machine, nm, sizeof(nm));
 185                         name = nm;
 186                         name_len = strlen(nm) + 1;
 187                 } else {
 188                         name = pos->long_name;
 189                         name_len = pos->long_name_len + 1;
 190                 }
 191
 192                 err = write_buildid(name, name_len, pos->build_id,
 193                                     pid, misc, fd);
 194                 if (err)
 195                         return err;
 196         }
 197
 198         return 0;
 199 }
 200
 201 static int machine__write_buildid_table(struct machine *machine, int fd)
 202 {
 203         int err;
 204         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 205             umisc = PERF_RECORD_MISC_USER;
 206
 207         if (!machine__is_host(machine)) {
 208                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 209                 umisc = PERF_RECORD_MISC_GUEST_USER;
 210         }
 211
 212         err = __dsos__write_buildid_table(&machine->kernel_dsos.head, machine,
 213                                           machine->pid, kmisc, fd);
 214         if (err == 0)
 215                 err = __dsos__write_buildid_table(&machine->user_dsos.head,
 216                                                   machine, machine->pid, umisc,
 217                                                   fd);
 218         return err;
 219 }
 220
 221 int perf_session__write_buildid_table(struct perf_session *session, int fd)
 222 {
 223         struct rb_node *nd;
 224         int err = machine__write_buildid_table(&session->machines.host, fd);
 225
 226         if (err)
 227                 return err;
 228
 229         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 230                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 231                 err = machine__write_buildid_table(pos, fd);
 232                 if (err)
 233                         break;
 234         }
 235         return err;
 236 }
 237
 238 static int __dsos__hit_all(struct list_head *head)
 239 {
 240         struct dso *pos;
 241
 242         list_for_each_entry(pos, head, node)
 243                 pos->hit = true;
 244
 245         return 0;
 246 }
 247
 248 static int machine__hit_all_dsos(struct machine *machine)
 249 {
 250         int err;
 251
 252         err = __dsos__hit_all(&machine->kernel_dsos.head);
 253         if (err)
 254                 return err;
 255
 256         return __dsos__hit_all(&machine->user_dsos.head);
 257 }
 258
 259 int dsos__hit_all(struct perf_session *session)
 260 {
 261         struct rb_node *nd;
 262         int err;
 263
 264         err = machine__hit_all_dsos(&session->machines.host);
 265         if (err)
 266                 return err;
 267
 268         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 269                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 270
 271                 err = machine__hit_all_dsos(pos);
 272                 if (err)
 273                         return err;
 274         }
 275
 276         return 0;
 277 }
 278
 279 void disable_buildid_cache(void)
 280 {
 281         no_buildid_cache = true;
 282 }
 283
 284 static char *build_id_cache__dirname_from_path(const char *name,
 285                                                bool is_kallsyms, bool is_vdso)
 286 {
 287         char *realname = (char *)name, *filename;
 288         bool slash = is_kallsyms || is_vdso;
 289
 290         if (!slash) {
 291                 realname = realpath(name, NULL);
 292                 if (!realname)
 293                         return NULL;
 294         }
 295
 296         if (asprintf(&filename, "%s%s%s", buildid_dir, slash ? "/" : "",
 297                      is_vdso ? DSO__NAME_VDSO : realname) < 0)
 298                 filename = NULL;
 299
 300         if (!slash)
 301                 free(realname);
 302
 303         return filename;
 304 }
 305
 306 int build_id_cache__list_build_ids(const char *pathname,
 307                                    struct strlist **result)
 308 {
 309         struct strlist *list;
 310         char *dir_name;
 311         DIR *dir;
 312         struct dirent *d;
 313         int ret = 0;
 314
 315         list = strlist__new(true, NULL);
 316         dir_name = build_id_cache__dirname_from_path(pathname, false, false);
 317         if (!list || !dir_name) {
 318                 ret = -ENOMEM;
 319                 goto out;
 320         }
 321
 322         /* List up all dirents */
 323         dir = opendir(dir_name);
 324         if (!dir) {
 325                 ret = -errno;
 326                 goto out;
 327         }
 328
 329         while ((d = readdir(dir)) != NULL) {
 330                 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
 331                         continue;
 332                 strlist__add(list, d->d_name);
 333         }
 334         closedir(dir);
 335
 336 out:
 337         free(dir_name);
 338         if (ret)
 339                 strlist__delete(list);
 340         else
 341                 *result = list;
 342
 343         return ret;
 344 }
 345
 346 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 347                           bool is_kallsyms, bool is_vdso)
 348 {
 349         const size_t size = PATH_MAX;
 350         char *realname = NULL, *filename = NULL, *dir_name = NULL,
 351              *linkname = zalloc(size), *targetname, *tmp;
 352         int err = -1;
 353
 354         if (!is_kallsyms) {
 355                 realname = realpath(name, NULL);
 356                 if (!realname)
 357                         goto out_free;
 358         }
 359
 360         dir_name = build_id_cache__dirname_from_path(name, is_kallsyms, is_vdso);
 361         if (!dir_name)
 362                 goto out_free;
 363
 364         if (mkdir_p(dir_name, 0755))
 365                 goto out_free;
 366
 367         if (asprintf(&filename, "%s/%s", dir_name, sbuild_id) < 0) {
 368                 filename = NULL;
 369                 goto out_free;
 370         }
 371
 372         if (access(filename, F_OK)) {
 373                 if (is_kallsyms) {
 374                          if (copyfile("/proc/kallsyms", filename))
 375                                 goto out_free;
 376                 } else if (link(realname, filename) && errno != EEXIST &&
 377                                 copyfile(name, filename))
 378                         goto out_free;
 379         }
 380
 381         if (!build_id__filename(sbuild_id, linkname, size))
 382                 goto out_free;
 383         tmp = strrchr(linkname, '/');
 384         *tmp = '\0';
 385
 386         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 387                 goto out_free;
 388
 389         *tmp = '/';
 390         targetname = filename + strlen(buildid_dir) - 5;
 391         memcpy(targetname, "../..", 5);
 392
 393         if (symlink(targetname, linkname) == 0)
 394                 err = 0;
 395 out_free:
 396         if (!is_kallsyms)
 397                 free(realname);
 398         free(filename);
 399         free(dir_name);
 400         free(linkname);
 401         return err;
 402 }
 403
 404 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 405                                  const char *name, bool is_kallsyms,
 406                                  bool is_vdso)
 407 {
 408         char sbuild_id[BUILD_ID_SIZE * 2 + 1];
 409
 410         build_id__sprintf(build_id, build_id_size, sbuild_id);
 411
 412         return build_id_cache__add_s(sbuild_id, name, is_kallsyms, is_vdso);
 413 }
 414
 415 bool build_id_cache__cached(const char *sbuild_id)
 416 {
 417         bool ret = false;
 418         char *filename = build_id__filename(sbuild_id, NULL, 0);
 419
 420         if (filename && !access(filename, F_OK))
 421                 ret = true;
 422         free(filename);
 423
 424         return ret;
 425 }
 426
 427 int build_id_cache__remove_s(const char *sbuild_id)
 428 {
 429         const size_t size = PATH_MAX;
 430         char *filename = zalloc(size),
 431              *linkname = zalloc(size), *tmp;
 432         int err = -1;
 433
 434         if (filename == NULL || linkname == NULL)
 435                 goto out_free;
 436
 437         if (!build_id__filename(sbuild_id, linkname, size))
 438                 goto out_free;
 439
 440         if (access(linkname, F_OK))
 441                 goto out_free;
 442
 443         if (readlink(linkname, filename, size - 1) < 0)
 444                 goto out_free;
 445
 446         if (unlink(linkname))
 447                 goto out_free;
 448
 449         /*
 450          * Since the link is relative, we must make it absolute:
 451          */
 452         tmp = strrchr(linkname, '/') + 1;
 453         snprintf(tmp, size - (tmp - linkname), "%s", filename);
 454
 455         if (unlink(linkname))
 456                 goto out_free;
 457
 458         err = 0;
 459 out_free:
 460         free(filename);
 461         free(linkname);
 462         return err;
 463 }
 464
 465 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 466 {
 467         bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
 468         bool is_vdso = dso__is_vdso(dso);
 469         const char *name = dso->long_name;
 470         char nm[PATH_MAX];
 471
 472         if (dso__is_kcore(dso)) {
 473                 is_kallsyms = true;
 474                 machine__mmap_name(machine, nm, sizeof(nm));
 475                 name = nm;
 476         }
 477         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 478                                      is_kallsyms, is_vdso);
 479 }
 480
 481 static int __dsos__cache_build_ids(struct list_head *head,
 482                                    struct machine *machine)
 483 {
 484         struct dso *pos;
 485         int err = 0;
 486
 487         dsos__for_each_with_build_id(pos, head)
 488                 if (dso__cache_build_id(pos, machine))
 489                         err = -1;
 490
 491         return err;
 492 }
 493
 494 static int machine__cache_build_ids(struct machine *machine)
 495 {
 496         int ret = __dsos__cache_build_ids(&machine->kernel_dsos.head, machine);
 497         ret |= __dsos__cache_build_ids(&machine->user_dsos.head, machine);
 498         return ret;
 499 }
 500
 501 int perf_session__cache_build_ids(struct perf_session *session)
 502 {
 503         struct rb_node *nd;
 504         int ret;
 505
 506         if (no_buildid_cache)
 507                 return 0;
 508
 509         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 510                 return -1;
 511
 512         ret = machine__cache_build_ids(&session->machines.host);
 513
 514         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 515                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 516                 ret |= machine__cache_build_ids(pos);
 517         }
 518         return ret ? -1 : 0;
 519 }
 520
 521 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 522 {
 523         bool ret;
 524
 525         ret  = __dsos__read_build_ids(&machine->kernel_dsos.head, with_hits);
 526         ret |= __dsos__read_build_ids(&machine->user_dsos.head, with_hits);
 527         return ret;
 528 }
 529
 530 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 531 {
 532         struct rb_node *nd;
 533         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 534
 535         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 536                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 537                 ret |= machine__read_build_ids(pos, with_hits);
 538         }
 539
 540         return ret;
 541 }