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 machine__write_buildid_table(struct machine *machine, int fd)
 166 {
 167         int err = 0;
 168         char nm[PATH_MAX];
 169         struct dso *pos;
 170         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 171             umisc = PERF_RECORD_MISC_USER;
 172
 173         if (!machine__is_host(machine)) {
 174                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 175                 umisc = PERF_RECORD_MISC_GUEST_USER;
 176         }
 177
 178         dsos__for_each_with_build_id(pos, &machine->dsos.head) {
 179                 const char *name;
 180                 size_t name_len;
 181
 182                 if (!pos->hit)
 183                         continue;
 184
 185                 if (dso__is_vdso(pos)) {
 186                         name = pos->short_name;
 187                         name_len = pos->short_name_len + 1;
 188                 } else if (dso__is_kcore(pos)) {
 189                         machine__mmap_name(machine, nm, sizeof(nm));
 190                         name = nm;
 191                         name_len = strlen(nm) + 1;
 192                 } else {
 193                         name = pos->long_name;
 194                         name_len = pos->long_name_len + 1;
 195                 }
 196
 197                 err = write_buildid(name, name_len, pos->build_id, machine->pid,
 198                                     pos->kernel ? kmisc : umisc, fd);
 199                 if (err)
 200                         break;
 201         }
 202
 203         return err;
 204 }
 205
 206 int perf_session__write_buildid_table(struct perf_session *session, int fd)
 207 {
 208         struct rb_node *nd;
 209         int err = machine__write_buildid_table(&session->machines.host, fd);
 210
 211         if (err)
 212                 return err;
 213
 214         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 215                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 216                 err = machine__write_buildid_table(pos, fd);
 217                 if (err)
 218                         break;
 219         }
 220         return err;
 221 }
 222
 223 static int __dsos__hit_all(struct list_head *head)
 224 {
 225         struct dso *pos;
 226
 227         list_for_each_entry(pos, head, node)
 228                 pos->hit = true;
 229
 230         return 0;
 231 }
 232
 233 static int machine__hit_all_dsos(struct machine *machine)
 234 {
 235         return __dsos__hit_all(&machine->dsos.head);
 236 }
 237
 238 int dsos__hit_all(struct perf_session *session)
 239 {
 240         struct rb_node *nd;
 241         int err;
 242
 243         err = machine__hit_all_dsos(&session->machines.host);
 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
 250                 err = machine__hit_all_dsos(pos);
 251                 if (err)
 252                         return err;
 253         }
 254
 255         return 0;
 256 }
 257
 258 void disable_buildid_cache(void)
 259 {
 260         no_buildid_cache = true;
 261 }
 262
 263 static char *build_id_cache__dirname_from_path(const char *name,
 264                                                bool is_kallsyms, bool is_vdso)
 265 {
 266         char *realname = (char *)name, *filename;
 267         bool slash = is_kallsyms || is_vdso;
 268
 269         if (!slash) {
 270                 realname = realpath(name, NULL);
 271                 if (!realname)
 272                         return NULL;
 273         }
 274
 275         if (asprintf(&filename, "%s%s%s", buildid_dir, slash ? "/" : "",
 276                      is_vdso ? DSO__NAME_VDSO : realname) < 0)
 277                 filename = NULL;
 278
 279         if (!slash)
 280                 free(realname);
 281
 282         return filename;
 283 }
 284
 285 int build_id_cache__list_build_ids(const char *pathname,
 286                                    struct strlist **result)
 287 {
 288         struct strlist *list;
 289         char *dir_name;
 290         DIR *dir;
 291         struct dirent *d;
 292         int ret = 0;
 293
 294         list = strlist__new(true, NULL);
 295         dir_name = build_id_cache__dirname_from_path(pathname, false, false);
 296         if (!list || !dir_name) {
 297                 ret = -ENOMEM;
 298                 goto out;
 299         }
 300
 301         /* List up all dirents */
 302         dir = opendir(dir_name);
 303         if (!dir) {
 304                 ret = -errno;
 305                 goto out;
 306         }
 307
 308         while ((d = readdir(dir)) != NULL) {
 309                 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
 310                         continue;
 311                 strlist__add(list, d->d_name);
 312         }
 313         closedir(dir);
 314
 315 out:
 316         free(dir_name);
 317         if (ret)
 318                 strlist__delete(list);
 319         else
 320                 *result = list;
 321
 322         return ret;
 323 }
 324
 325 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 326                           bool is_kallsyms, bool is_vdso)
 327 {
 328         const size_t size = PATH_MAX;
 329         char *realname = NULL, *filename = NULL, *dir_name = NULL,
 330              *linkname = zalloc(size), *targetname, *tmp;
 331         int err = -1;
 332
 333         if (!is_kallsyms) {
 334                 realname = realpath(name, NULL);
 335                 if (!realname)
 336                         goto out_free;
 337         }
 338
 339         dir_name = build_id_cache__dirname_from_path(name, is_kallsyms, is_vdso);
 340         if (!dir_name)
 341                 goto out_free;
 342
 343         if (mkdir_p(dir_name, 0755))
 344                 goto out_free;
 345
 346         if (asprintf(&filename, "%s/%s", dir_name, sbuild_id) < 0) {
 347                 filename = NULL;
 348                 goto out_free;
 349         }
 350
 351         if (access(filename, F_OK)) {
 352                 if (is_kallsyms) {
 353                          if (copyfile("/proc/kallsyms", filename))
 354                                 goto out_free;
 355                 } else if (link(realname, filename) && errno != EEXIST &&
 356                                 copyfile(name, filename))
 357                         goto out_free;
 358         }
 359
 360         if (!build_id__filename(sbuild_id, linkname, size))
 361                 goto out_free;
 362         tmp = strrchr(linkname, '/');
 363         *tmp = '\0';
 364
 365         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 366                 goto out_free;
 367
 368         *tmp = '/';
 369         targetname = filename + strlen(buildid_dir) - 5;
 370         memcpy(targetname, "../..", 5);
 371
 372         if (symlink(targetname, linkname) == 0)
 373                 err = 0;
 374 out_free:
 375         if (!is_kallsyms)
 376                 free(realname);
 377         free(filename);
 378         free(dir_name);
 379         free(linkname);
 380         return err;
 381 }
 382
 383 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 384                                  const char *name, bool is_kallsyms,
 385                                  bool is_vdso)
 386 {
 387         char sbuild_id[BUILD_ID_SIZE * 2 + 1];
 388
 389         build_id__sprintf(build_id, build_id_size, sbuild_id);
 390
 391         return build_id_cache__add_s(sbuild_id, name, is_kallsyms, is_vdso);
 392 }
 393
 394 bool build_id_cache__cached(const char *sbuild_id)
 395 {
 396         bool ret = false;
 397         char *filename = build_id__filename(sbuild_id, NULL, 0);
 398
 399         if (filename && !access(filename, F_OK))
 400                 ret = true;
 401         free(filename);
 402
 403         return ret;
 404 }
 405
 406 int build_id_cache__remove_s(const char *sbuild_id)
 407 {
 408         const size_t size = PATH_MAX;
 409         char *filename = zalloc(size),
 410              *linkname = zalloc(size), *tmp;
 411         int err = -1;
 412
 413         if (filename == NULL || linkname == NULL)
 414                 goto out_free;
 415
 416         if (!build_id__filename(sbuild_id, linkname, size))
 417                 goto out_free;
 418
 419         if (access(linkname, F_OK))
 420                 goto out_free;
 421
 422         if (readlink(linkname, filename, size - 1) < 0)
 423                 goto out_free;
 424
 425         if (unlink(linkname))
 426                 goto out_free;
 427
 428         /*
 429          * Since the link is relative, we must make it absolute:
 430          */
 431         tmp = strrchr(linkname, '/') + 1;
 432         snprintf(tmp, size - (tmp - linkname), "%s", filename);
 433
 434         if (unlink(linkname))
 435                 goto out_free;
 436
 437         err = 0;
 438 out_free:
 439         free(filename);
 440         free(linkname);
 441         return err;
 442 }
 443
 444 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 445 {
 446         bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
 447         bool is_vdso = dso__is_vdso(dso);
 448         const char *name = dso->long_name;
 449         char nm[PATH_MAX];
 450
 451         if (dso__is_kcore(dso)) {
 452                 is_kallsyms = true;
 453                 machine__mmap_name(machine, nm, sizeof(nm));
 454                 name = nm;
 455         }
 456         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 457                                      is_kallsyms, is_vdso);
 458 }
 459
 460 static int __dsos__cache_build_ids(struct list_head *head,
 461                                    struct machine *machine)
 462 {
 463         struct dso *pos;
 464         int err = 0;
 465
 466         dsos__for_each_with_build_id(pos, head)
 467                 if (dso__cache_build_id(pos, machine))
 468                         err = -1;
 469
 470         return err;
 471 }
 472
 473 static int machine__cache_build_ids(struct machine *machine)
 474 {
 475         return __dsos__cache_build_ids(&machine->dsos.head, machine);
 476 }
 477
 478 int perf_session__cache_build_ids(struct perf_session *session)
 479 {
 480         struct rb_node *nd;
 481         int ret;
 482
 483         if (no_buildid_cache)
 484                 return 0;
 485
 486         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 487                 return -1;
 488
 489         ret = machine__cache_build_ids(&session->machines.host);
 490
 491         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 492                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 493                 ret |= machine__cache_build_ids(pos);
 494         }
 495         return ret ? -1 : 0;
 496 }
 497
 498 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 499 {
 500         return __dsos__read_build_ids(&machine->dsos.head, with_hits);
 501 }
 502
 503 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 504 {
 505         struct rb_node *nd;
 506         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 507
 508         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 509                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 510                 ret |= machine__read_build_ids(pos, with_hits);
 511         }
 512
 513         return ret;
 514 }