tools/perf/util/header.c

   1 #define _FILE_OFFSET_BITS 64
   2
   3 #include <sys/types.h>
   4 #include <byteswap.h>
   5 #include <unistd.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <linux/list.h>
   9 #include <linux/kernel.h>
  10
  11 #include "evlist.h"
  12 #include "evsel.h"
  13 #include "util.h"
  14 #include "header.h"
  15 #include "../perf.h"
  16 #include "trace-event.h"
  17 #include "session.h"
  18 #include "symbol.h"
  19 #include "debug.h"
  20
  21 static bool no_buildid_cache = false;
  22
  23 static int event_count;
  24 static struct perf_trace_event_type *events;
  25
  26 int perf_header__push_event(u64 id, const char *name)
  27 {
  28         if (strlen(name) > MAX_EVENT_NAME)
  29                 pr_warning("Event %s will be truncated\n", name);
  30
  31         if (!events) {
  32                 events = malloc(sizeof(struct perf_trace_event_type));
  33                 if (events == NULL)
  34                         return -ENOMEM;
  35         } else {
  36                 struct perf_trace_event_type *nevents;
  37
  38                 nevents = realloc(events, (event_count + 1) * sizeof(*events));
  39                 if (nevents == NULL)
  40                         return -ENOMEM;
  41                 events = nevents;
  42         }
  43         memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
  44         events[event_count].event_id = id;
  45         strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
  46         event_count++;
  47         return 0;
  48 }
  49
  50 char *perf_header__find_event(u64 id)
  51 {
  52         int i;
  53         for (i = 0 ; i < event_count; i++) {
  54                 if (events[i].event_id == id)
  55                         return events[i].name;
  56         }
  57         return NULL;
  58 }
  59
  60 static const char *__perf_magic = "PERFFILE";
  61
  62 #define PERF_MAGIC      (*(u64 *)__perf_magic)
  63
  64 struct perf_file_attr {
  65         struct perf_event_attr  attr;
  66         struct perf_file_section        ids;
  67 };
  68
  69 void perf_header__set_feat(struct perf_header *header, int feat)
  70 {
  71         set_bit(feat, header->adds_features);
  72 }
  73
  74 void perf_header__clear_feat(struct perf_header *header, int feat)
  75 {
  76         clear_bit(feat, header->adds_features);
  77 }
  78
  79 bool perf_header__has_feat(const struct perf_header *header, int feat)
  80 {
  81         return test_bit(feat, header->adds_features);
  82 }
  83
  84 static int do_write(int fd, const void *buf, size_t size)
  85 {
  86         while (size) {
  87                 int ret = write(fd, buf, size);
  88
  89                 if (ret < 0)
  90                         return -errno;
  91
  92                 size -= ret;
  93                 buf += ret;
  94         }
  95
  96         return 0;
  97 }
  98
  99 #define NAME_ALIGN 64
 100
 101 static int write_padded(int fd, const void *bf, size_t count,
 102                         size_t count_aligned)
 103 {
 104         static const char zero_buf[NAME_ALIGN];
 105         int err = do_write(fd, bf, count);
 106
 107         if (!err)
 108                 err = do_write(fd, zero_buf, count_aligned - count);
 109
 110         return err;
 111 }
 112
 113 #define dsos__for_each_with_build_id(pos, head) \
 114         list_for_each_entry(pos, head, node)    \
 115                 if (!pos->has_build_id)         \
 116                         continue;               \
 117                 else
 118
 119 static int __dsos__write_buildid_table(struct list_head *head, pid_t pid,
 120                                 u16 misc, int fd)
 121 {
 122         struct dso *pos;
 123
 124         dsos__for_each_with_build_id(pos, head) {
 125                 int err;
 126                 struct build_id_event b;
 127                 size_t len;
 128
 129                 if (!pos->hit)
 130                         continue;
 131                 len = pos->long_name_len + 1;
 132                 len = ALIGN(len, NAME_ALIGN);
 133                 memset(&b, 0, sizeof(b));
 134                 memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
 135                 b.pid = pid;
 136                 b.header.misc = misc;
 137                 b.header.size = sizeof(b) + len;
 138                 err = do_write(fd, &b, sizeof(b));
 139                 if (err < 0)
 140                         return err;
 141                 err = write_padded(fd, pos->long_name,
 142                                    pos->long_name_len + 1, len);
 143                 if (err < 0)
 144                         return err;
 145         }
 146
 147         return 0;
 148 }
 149
 150 static int machine__write_buildid_table(struct machine *machine, int fd)
 151 {
 152         int err;
 153         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 154             umisc = PERF_RECORD_MISC_USER;
 155
 156         if (!machine__is_host(machine)) {
 157                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 158                 umisc = PERF_RECORD_MISC_GUEST_USER;
 159         }
 160
 161         err = __dsos__write_buildid_table(&machine->kernel_dsos, machine->pid,
 162                                           kmisc, fd);
 163         if (err == 0)
 164                 err = __dsos__write_buildid_table(&machine->user_dsos,
 165                                                   machine->pid, umisc, fd);
 166         return err;
 167 }
 168
 169 static int dsos__write_buildid_table(struct perf_header *header, int fd)
 170 {
 171         struct perf_session *session = container_of(header,
 172                         struct perf_session, header);
 173         struct rb_node *nd;
 174         int err = machine__write_buildid_table(&session->host_machine, fd);
 175
 176         if (err)
 177                 return err;
 178
 179         for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
 180                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 181                 err = machine__write_buildid_table(pos, fd);
 182                 if (err)
 183                         break;
 184         }
 185         return err;
 186 }
 187
 188 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 189                           const char *name, bool is_kallsyms)
 190 {
 191         const size_t size = PATH_MAX;
 192         char *realname, *filename = zalloc(size),
 193              *linkname = zalloc(size), *targetname;
 194         int len, err = -1;
 195
 196         if (is_kallsyms) {
 197                 if (symbol_conf.kptr_restrict) {
 198                         pr_debug("Not caching a kptr_restrict'ed /proc/kallsyms\n");
 199                         return 0;
 200                 }
 201                 realname = (char *)name;
 202         } else
 203                 realname = realpath(name, NULL);
 204
 205         if (realname == NULL || filename == NULL || linkname == NULL)
 206                 goto out_free;
 207
 208         len = snprintf(filename, size, "%s%s%s",
 209                        debugdir, is_kallsyms ? "/" : "", realname);
 210         if (mkdir_p(filename, 0755))
 211                 goto out_free;
 212
 213         snprintf(filename + len, sizeof(filename) - len, "/%s", sbuild_id);
 214
 215         if (access(filename, F_OK)) {
 216                 if (is_kallsyms) {
 217                          if (copyfile("/proc/kallsyms", filename))
 218                                 goto out_free;
 219                 } else if (link(realname, filename) && copyfile(name, filename))
 220                         goto out_free;
 221         }
 222
 223         len = snprintf(linkname, size, "%s/.build-id/%.2s",
 224                        debugdir, sbuild_id);
 225
 226         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 227                 goto out_free;
 228
 229         snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
 230         targetname = filename + strlen(debugdir) - 5;
 231         memcpy(targetname, "../..", 5);
 232
 233         if (symlink(targetname, linkname) == 0)
 234                 err = 0;
 235 out_free:
 236         if (!is_kallsyms)
 237                 free(realname);
 238         free(filename);
 239         free(linkname);
 240         return err;
 241 }
 242
 243 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 244                                  const char *name, const char *debugdir,
 245                                  bool is_kallsyms)
 246 {
 247         char sbuild_id[BUILD_ID_SIZE * 2 + 1];
 248
 249         build_id__sprintf(build_id, build_id_size, sbuild_id);
 250
 251         return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
 252 }
 253
 254 int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
 255 {
 256         const size_t size = PATH_MAX;
 257         char *filename = zalloc(size),
 258              *linkname = zalloc(size);
 259         int err = -1;
 260
 261         if (filename == NULL || linkname == NULL)
 262                 goto out_free;
 263
 264         snprintf(linkname, size, "%s/.build-id/%.2s/%s",
 265                  debugdir, sbuild_id, sbuild_id + 2);
 266
 267         if (access(linkname, F_OK))
 268                 goto out_free;
 269
 270         if (readlink(linkname, filename, size) < 0)
 271                 goto out_free;
 272
 273         if (unlink(linkname))
 274                 goto out_free;
 275
 276         /*
 277          * Since the link is relative, we must make it absolute:
 278          */
 279         snprintf(linkname, size, "%s/.build-id/%.2s/%s",
 280                  debugdir, sbuild_id, filename);
 281
 282         if (unlink(linkname))
 283                 goto out_free;
 284
 285         err = 0;
 286 out_free:
 287         free(filename);
 288         free(linkname);
 289         return err;
 290 }
 291
 292 static int dso__cache_build_id(struct dso *dso, const char *debugdir)
 293 {
 294         bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
 295
 296         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id),
 297                                      dso->long_name, debugdir, is_kallsyms);
 298 }
 299
 300 static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
 301 {
 302         struct dso *pos;
 303         int err = 0;
 304
 305         dsos__for_each_with_build_id(pos, head)
 306                 if (dso__cache_build_id(pos, debugdir))
 307                         err = -1;
 308
 309         return err;
 310 }
 311
 312 static int machine__cache_build_ids(struct machine *machine, const char *debugdir)
 313 {
 314         int ret = __dsos__cache_build_ids(&machine->kernel_dsos, debugdir);
 315         ret |= __dsos__cache_build_ids(&machine->user_dsos, debugdir);
 316         return ret;
 317 }
 318
 319 static int perf_session__cache_build_ids(struct perf_session *session)
 320 {
 321         struct rb_node *nd;
 322         int ret;
 323         char debugdir[PATH_MAX];
 324
 325         snprintf(debugdir, sizeof(debugdir), "%s", buildid_dir);
 326
 327         if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
 328                 return -1;
 329
 330         ret = machine__cache_build_ids(&session->host_machine, debugdir);
 331
 332         for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
 333                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 334                 ret |= machine__cache_build_ids(pos, debugdir);
 335         }
 336         return ret ? -1 : 0;
 337 }
 338
 339 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 340 {
 341         bool ret = __dsos__read_build_ids(&machine->kernel_dsos, with_hits);
 342         ret |= __dsos__read_build_ids(&machine->user_dsos, with_hits);
 343         return ret;
 344 }
 345
 346 static bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 347 {
 348         struct rb_node *nd;
 349         bool ret = machine__read_build_ids(&session->host_machine, with_hits);
 350
 351         for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
 352                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 353                 ret |= machine__read_build_ids(pos, with_hits);
 354         }
 355
 356         return ret;
 357 }
 358
 359 static int perf_header__adds_write(struct perf_header *header,
 360                                    struct perf_evlist *evlist, int fd)
 361 {
 362         int nr_sections;
 363         struct perf_session *session;
 364         struct perf_file_section *feat_sec;
 365         int sec_size;
 366         u64 sec_start;
 367         int idx = 0, err;
 368
 369         session = container_of(header, struct perf_session, header);
 370
 371         if (perf_header__has_feat(header, HEADER_BUILD_ID &&
 372             !perf_session__read_build_ids(session, true)))
 373                 perf_header__clear_feat(header, HEADER_BUILD_ID);
 374
 375         nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
 376         if (!nr_sections)
 377                 return 0;
 378
 379         feat_sec = calloc(sizeof(*feat_sec), nr_sections);
 380         if (feat_sec == NULL)
 381                 return -ENOMEM;
 382
 383         sec_size = sizeof(*feat_sec) * nr_sections;
 384
 385         sec_start = header->data_offset + header->data_size;
 386         lseek(fd, sec_start + sec_size, SEEK_SET);
 387
 388         if (perf_header__has_feat(header, HEADER_TRACE_INFO)) {
 389                 struct perf_file_section *trace_sec;
 390
 391                 trace_sec = &feat_sec[idx++];
 392
 393                 /* Write trace info */
 394                 trace_sec->offset = lseek(fd, 0, SEEK_CUR);
 395                 read_tracing_data(fd, &evlist->entries);
 396                 trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
 397         }
 398
 399         if (perf_header__has_feat(header, HEADER_BUILD_ID)) {
 400                 struct perf_file_section *buildid_sec;
 401
 402                 buildid_sec = &feat_sec[idx++];
 403
 404                 /* Write build-ids */
 405                 buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
 406                 err = dsos__write_buildid_table(header, fd);
 407                 if (err < 0) {
 408                         pr_debug("failed to write buildid table\n");
 409                         goto out_free;
 410                 }
 411                 buildid_sec->size = lseek(fd, 0, SEEK_CUR) -
 412                                           buildid_sec->offset;
 413                 if (!no_buildid_cache)
 414                         perf_session__cache_build_ids(session);
 415         }
 416
 417         lseek(fd, sec_start, SEEK_SET);
 418         err = do_write(fd, feat_sec, sec_size);
 419         if (err < 0)
 420                 pr_debug("failed to write feature section\n");
 421 out_free:
 422         free(feat_sec);
 423         return err;
 424 }
 425
 426 int perf_header__write_pipe(int fd)
 427 {
 428         struct perf_pipe_file_header f_header;
 429         int err;
 430
 431         f_header = (struct perf_pipe_file_header){
 432                 .magic     = PERF_MAGIC,
 433                 .size      = sizeof(f_header),
 434         };
 435
 436         err = do_write(fd, &f_header, sizeof(f_header));
 437         if (err < 0) {
 438                 pr_debug("failed to write perf pipe header\n");
 439                 return err;
 440         }
 441
 442         return 0;
 443 }
 444
 445 int perf_session__write_header(struct perf_session *session,
 446                                struct perf_evlist *evlist,
 447                                int fd, bool at_exit)
 448 {
 449         struct perf_file_header f_header;
 450         struct perf_file_attr   f_attr;
 451         struct perf_header *header = &session->header;
 452         struct perf_evsel *attr, *pair = NULL;
 453         int err;
 454
 455         lseek(fd, sizeof(f_header), SEEK_SET);
 456
 457         if (session->evlist != evlist)
 458                 pair = list_entry(session->evlist->entries.next, struct perf_evsel, node);
 459
 460         list_for_each_entry(attr, &evlist->entries, node) {
 461                 attr->id_offset = lseek(fd, 0, SEEK_CUR);
 462                 err = do_write(fd, attr->id, attr->ids * sizeof(u64));
 463                 if (err < 0) {
 464 out_err_write:
 465                         pr_debug("failed to write perf header\n");
 466                         return err;
 467                 }
 468                 if (session->evlist != evlist) {
 469                         err = do_write(fd, pair->id, pair->ids * sizeof(u64));
 470                         if (err < 0)
 471                                 goto out_err_write;
 472                         attr->ids += pair->ids;
 473                         pair = list_entry(pair->node.next, struct perf_evsel, node);
 474                 }
 475         }
 476
 477         header->attr_offset = lseek(fd, 0, SEEK_CUR);
 478
 479         list_for_each_entry(attr, &evlist->entries, node) {
 480                 f_attr = (struct perf_file_attr){
 481                         .attr = attr->attr,
 482                         .ids  = {
 483                                 .offset = attr->id_offset,
 484                                 .size   = attr->ids * sizeof(u64),
 485                         }
 486                 };
 487                 err = do_write(fd, &f_attr, sizeof(f_attr));
 488                 if (err < 0) {
 489                         pr_debug("failed to write perf header attribute\n");
 490                         return err;
 491                 }
 492         }
 493
 494         header->event_offset = lseek(fd, 0, SEEK_CUR);
 495         header->event_size = event_count * sizeof(struct perf_trace_event_type);
 496         if (events) {
 497                 err = do_write(fd, events, header->event_size);
 498                 if (err < 0) {
 499                         pr_debug("failed to write perf header events\n");
 500                         return err;
 501                 }
 502         }
 503
 504         header->data_offset = lseek(fd, 0, SEEK_CUR);
 505
 506         if (at_exit) {
 507                 err = perf_header__adds_write(header, evlist, fd);
 508                 if (err < 0)
 509                         return err;
 510         }
 511
 512         f_header = (struct perf_file_header){
 513                 .magic     = PERF_MAGIC,
 514                 .size      = sizeof(f_header),
 515                 .attr_size = sizeof(f_attr),
 516                 .attrs = {
 517                         .offset = header->attr_offset,
 518                         .size   = evlist->nr_entries * sizeof(f_attr),
 519                 },
 520                 .data = {
 521                         .offset = header->data_offset,
 522                         .size   = header->data_size,
 523                 },
 524                 .event_types = {
 525                         .offset = header->event_offset,
 526                         .size   = header->event_size,
 527                 },
 528         };
 529
 530         memcpy(&f_header.adds_features, &header->adds_features, sizeof(header->adds_features));
 531
 532         lseek(fd, 0, SEEK_SET);
 533         err = do_write(fd, &f_header, sizeof(f_header));
 534         if (err < 0) {
 535                 pr_debug("failed to write perf header\n");
 536                 return err;
 537         }
 538         lseek(fd, header->data_offset + header->data_size, SEEK_SET);
 539
 540         header->frozen = 1;
 541         return 0;
 542 }
 543
 544 static int perf_header__getbuffer64(struct perf_header *header,
 545                                     int fd, void *buf, size_t size)
 546 {
 547         if (readn(fd, buf, size) <= 0)
 548                 return -1;
 549
 550         if (header->needs_swap)
 551                 mem_bswap_64(buf, size);
 552
 553         return 0;
 554 }
 555
 556 int perf_header__process_sections(struct perf_header *header, int fd,
 557                                   int (*process)(struct perf_file_section *section,
 558                                                  struct perf_header *ph,
 559                                                  int feat, int fd))
 560 {
 561         struct perf_file_section *feat_sec;
 562         int nr_sections;
 563         int sec_size;
 564         int idx = 0;
 565         int err = -1, feat = 1;
 566
 567         nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
 568         if (!nr_sections)
 569                 return 0;
 570
 571         feat_sec = calloc(sizeof(*feat_sec), nr_sections);
 572         if (!feat_sec)
 573                 return -1;
 574
 575         sec_size = sizeof(*feat_sec) * nr_sections;
 576
 577         lseek(fd, header->data_offset + header->data_size, SEEK_SET);
 578
 579         if (perf_header__getbuffer64(header, fd, feat_sec, sec_size))
 580                 goto out_free;
 581
 582         err = 0;
 583         while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
 584                 if (perf_header__has_feat(header, feat)) {
 585                         struct perf_file_section *sec = &feat_sec[idx++];
 586
 587                         err = process(sec, header, feat, fd);
 588                         if (err < 0)
 589                                 break;
 590                 }
 591                 ++feat;
 592         }
 593 out_free:
 594         free(feat_sec);
 595         return err;
 596 }
 597
 598 int perf_file_header__read(struct perf_file_header *header,
 599                            struct perf_header *ph, int fd)
 600 {
 601         lseek(fd, 0, SEEK_SET);
 602
 603         if (readn(fd, header, sizeof(*header)) <= 0 ||
 604             memcmp(&header->magic, __perf_magic, sizeof(header->magic)))
 605                 return -1;
 606
 607         if (header->attr_size != sizeof(struct perf_file_attr)) {
 608                 u64 attr_size = bswap_64(header->attr_size);
 609
 610                 if (attr_size != sizeof(struct perf_file_attr))
 611                         return -1;
 612
 613                 mem_bswap_64(header, offsetof(struct perf_file_header,
 614                                             adds_features));
 615                 ph->needs_swap = true;
 616         }
 617
 618         if (header->size != sizeof(*header)) {
 619                 /* Support the previous format */
 620                 if (header->size == offsetof(typeof(*header), adds_features))
 621                         bitmap_zero(header->adds_features, HEADER_FEAT_BITS);
 622                 else
 623                         return -1;
 624         }
 625
 626         memcpy(&ph->adds_features, &header->adds_features,
 627                sizeof(ph->adds_features));
 628         /*
 629          * FIXME: hack that assumes that if we need swap the perf.data file
 630          * may be coming from an arch with a different word-size, ergo different
 631          * DEFINE_BITMAP format, investigate more later, but for now its mostly
 632          * safe to assume that we have a build-id section. Trace files probably
 633          * have several other issues in this realm anyway...
 634          */
 635         if (ph->needs_swap) {
 636                 memset(&ph->adds_features, 0, sizeof(ph->adds_features));
 637                 perf_header__set_feat(ph, HEADER_BUILD_ID);
 638         }
 639
 640         ph->event_offset = header->event_types.offset;
 641         ph->event_size   = header->event_types.size;
 642         ph->data_offset  = header->data.offset;
 643         ph->data_size    = header->data.size;
 644         return 0;
 645 }
 646
 647 static int __event_process_build_id(struct build_id_event *bev,
 648                                     char *filename,
 649                                     struct perf_session *session)
 650 {
 651         int err = -1;
 652         struct list_head *head;
 653         struct machine *machine;
 654         u16 misc;
 655         struct dso *dso;
 656         enum dso_kernel_type dso_type;
 657
 658         machine = perf_session__findnew_machine(session, bev->pid);
 659         if (!machine)
 660                 goto out;
 661
 662         misc = bev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
 663
 664         switch (misc) {
 665         case PERF_RECORD_MISC_KERNEL:
 666                 dso_type = DSO_TYPE_KERNEL;
 667                 head = &machine->kernel_dsos;
 668                 break;
 669         case PERF_RECORD_MISC_GUEST_KERNEL:
 670                 dso_type = DSO_TYPE_GUEST_KERNEL;
 671                 head = &machine->kernel_dsos;
 672                 break;
 673         case PERF_RECORD_MISC_USER:
 674         case PERF_RECORD_MISC_GUEST_USER:
 675                 dso_type = DSO_TYPE_USER;
 676                 head = &machine->user_dsos;
 677                 break;
 678         default:
 679                 goto out;
 680         }
 681
 682         dso = __dsos__findnew(head, filename);
 683         if (dso != NULL) {
 684                 char sbuild_id[BUILD_ID_SIZE * 2 + 1];
 685
 686                 dso__set_build_id(dso, &bev->build_id);
 687
 688                 if (filename[0] == '[')
 689                         dso->kernel = dso_type;
 690
 691                 build_id__sprintf(dso->build_id, sizeof(dso->build_id),
 692                                   sbuild_id);
 693                 pr_debug("build id event received for %s: %s\n",
 694                          dso->long_name, sbuild_id);
 695         }
 696
 697         err = 0;
 698 out:
 699         return err;
 700 }
 701
 702 static int perf_header__read_build_ids_abi_quirk(struct perf_header *header,
 703                                                  int input, u64 offset, u64 size)
 704 {
 705         struct perf_session *session = container_of(header, struct perf_session, header);
 706         struct {
 707                 struct perf_event_header   header;
 708                 u8                         build_id[ALIGN(BUILD_ID_SIZE, sizeof(u64))];
 709                 char                       filename[0];
 710         } old_bev;
 711         struct build_id_event bev;
 712         char filename[PATH_MAX];
 713         u64 limit = offset + size;
 714
 715         while (offset < limit) {
 716                 ssize_t len;
 717
 718                 if (read(input, &old_bev, sizeof(old_bev)) != sizeof(old_bev))
 719                         return -1;
 720
 721                 if (header->needs_swap)
 722                         perf_event_header__bswap(&old_bev.header);
 723
 724                 len = old_bev.header.size - sizeof(old_bev);
 725                 if (read(input, filename, len) != len)
 726                         return -1;
 727
 728                 bev.header = old_bev.header;
 729
 730                 /*
 731                  * As the pid is the missing value, we need to fill
 732                  * it properly. The header.misc value give us nice hint.
 733                  */
 734                 bev.pid = HOST_KERNEL_ID;
 735                 if (bev.header.misc == PERF_RECORD_MISC_GUEST_USER ||
 736                     bev.header.misc == PERF_RECORD_MISC_GUEST_KERNEL)
 737                         bev.pid = DEFAULT_GUEST_KERNEL_ID;
 738
 739                 memcpy(bev.build_id, old_bev.build_id, sizeof(bev.build_id));
 740                 __event_process_build_id(&bev, filename, session);
 741
 742                 offset += bev.header.size;
 743         }
 744
 745         return 0;
 746 }
 747
 748 static int perf_header__read_build_ids(struct perf_header *header,
 749                                        int input, u64 offset, u64 size)
 750 {
 751         struct perf_session *session = container_of(header, struct perf_session, header);
 752         struct build_id_event bev;
 753         char filename[PATH_MAX];
 754         u64 limit = offset + size, orig_offset = offset;
 755         int err = -1;
 756
 757         while (offset < limit) {
 758                 ssize_t len;
 759
 760                 if (read(input, &bev, sizeof(bev)) != sizeof(bev))
 761                         goto out;
 762
 763                 if (header->needs_swap)
 764                         perf_event_header__bswap(&bev.header);
 765
 766                 len = bev.header.size - sizeof(bev);
 767                 if (read(input, filename, len) != len)
 768                         goto out;
 769                 /*
 770                  * The a1645ce1 changeset:
 771                  *
 772                  * "perf: 'perf kvm' tool for monitoring guest performance from host"
 773                  *
 774                  * Added a field to struct build_id_event that broke the file
 775                  * format.
 776                  *
 777                  * Since the kernel build-id is the first entry, process the
 778                  * table using the old format if the well known
 779                  * '[kernel.kallsyms]' string for the kernel build-id has the
 780                  * first 4 characters chopped off (where the pid_t sits).
 781                  */
 782                 if (memcmp(filename, "nel.kallsyms]", 13) == 0) {
 783                         if (lseek(input, orig_offset, SEEK_SET) == (off_t)-1)
 784                                 return -1;
 785                         return perf_header__read_build_ids_abi_quirk(header, input, offset, size);
 786                 }
 787
 788                 __event_process_build_id(&bev, filename, session);
 789
 790                 offset += bev.header.size;
 791         }
 792         err = 0;
 793 out:
 794         return err;
 795 }
 796
 797 static int perf_file_section__process(struct perf_file_section *section,
 798                                       struct perf_header *ph,
 799                                       int feat, int fd)
 800 {
 801         if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
 802                 pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
 803                           "%d, continuing...\n", section->offset, feat);
 804                 return 0;
 805         }
 806
 807         switch (feat) {
 808         case HEADER_TRACE_INFO:
 809                 trace_report(fd, false);
 810                 break;
 811
 812         case HEADER_BUILD_ID:
 813                 if (perf_header__read_build_ids(ph, fd, section->offset, section->size))
 814                         pr_debug("Failed to read buildids, continuing...\n");
 815                 break;
 816         default:
 817                 pr_debug("unknown feature %d, continuing...\n", feat);
 818         }
 819
 820         return 0;
 821 }
 822
 823 static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
 824                                        struct perf_header *ph, int fd,
 825                                        bool repipe)
 826 {
 827         if (readn(fd, header, sizeof(*header)) <= 0 ||
 828             memcmp(&header->magic, __perf_magic, sizeof(header->magic)))
 829                 return -1;
 830
 831         if (repipe && do_write(STDOUT_FILENO, header, sizeof(*header)) < 0)
 832                 return -1;
 833
 834         if (header->size != sizeof(*header)) {
 835                 u64 size = bswap_64(header->size);
 836
 837                 if (size != sizeof(*header))
 838                         return -1;
 839
 840                 ph->needs_swap = true;
 841         }
 842
 843         return 0;
 844 }
 845
 846 static int perf_header__read_pipe(struct perf_session *session, int fd)
 847 {
 848         struct perf_header *header = &session->header;
 849         struct perf_pipe_file_header f_header;
 850
 851         if (perf_file_header__read_pipe(&f_header, header, fd,
 852                                         session->repipe) < 0) {
 853                 pr_debug("incompatible file format\n");
 854                 return -EINVAL;
 855         }
 856
 857         session->fd = fd;
 858
 859         return 0;
 860 }
 861
 862 int perf_session__read_header(struct perf_session *session, int fd)
 863 {
 864         struct perf_header *header = &session->header;
 865         struct perf_file_header f_header;
 866         struct perf_file_attr   f_attr;
 867         u64                     f_id;
 868         int nr_attrs, nr_ids, i, j;
 869
 870         session->evlist = perf_evlist__new(NULL, NULL);
 871         if (session->evlist == NULL)
 872                 return -ENOMEM;
 873
 874         if (session->fd_pipe)
 875                 return perf_header__read_pipe(session, fd);
 876
 877         if (perf_file_header__read(&f_header, header, fd) < 0) {
 878                 pr_debug("incompatible file format\n");
 879                 return -EINVAL;
 880         }
 881
 882         nr_attrs = f_header.attrs.size / sizeof(f_attr);
 883         lseek(fd, f_header.attrs.offset, SEEK_SET);
 884
 885         for (i = 0; i < nr_attrs; i++) {
 886                 struct perf_evsel *evsel;
 887                 off_t tmp;
 888
 889                 if (readn(fd, &f_attr, sizeof(f_attr)) <= 0)
 890                         goto out_errno;
 891
 892                 if (header->needs_swap)
 893                         perf_event__attr_swap(&f_attr.attr);
 894
 895                 tmp = lseek(fd, 0, SEEK_CUR);
 896                 evsel = perf_evsel__new(&f_attr.attr, i);
 897
 898                 if (evsel == NULL)
 899                         goto out_delete_evlist;
 900                 /*
 901                  * Do it before so that if perf_evsel__alloc_id fails, this
 902                  * entry gets purged too at perf_evlist__delete().
 903                  */
 904                 perf_evlist__add(session->evlist, evsel);
 905
 906                 nr_ids = f_attr.ids.size / sizeof(u64);
 907                 /*
 908                  * We don't have the cpu and thread maps on the header, so
 909                  * for allocating the perf_sample_id table we fake 1 cpu and
 910                  * hattr->ids threads.
 911                  */
 912                 if (perf_evsel__alloc_id(evsel, 1, nr_ids))
 913                         goto out_delete_evlist;
 914
 915                 lseek(fd, f_attr.ids.offset, SEEK_SET);
 916
 917                 for (j = 0; j < nr_ids; j++) {
 918                         if (perf_header__getbuffer64(header, fd, &f_id, sizeof(f_id)))
 919                                 goto out_errno;
 920
 921                         perf_evlist__id_add(session->evlist, evsel, 0, j, f_id);
 922                 }
 923
 924                 lseek(fd, tmp, SEEK_SET);
 925         }
 926
 927         if (f_header.event_types.size) {
 928                 lseek(fd, f_header.event_types.offset, SEEK_SET);
 929                 events = malloc(f_header.event_types.size);
 930                 if (events == NULL)
 931                         return -ENOMEM;
 932                 if (perf_header__getbuffer64(header, fd, events,
 933                                              f_header.event_types.size))
 934                         goto out_errno;
 935                 event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
 936         }
 937
 938         perf_header__process_sections(header, fd, perf_file_section__process);
 939
 940         lseek(fd, header->data_offset, SEEK_SET);
 941
 942         header->frozen = 1;
 943         return 0;
 944 out_errno:
 945         return -errno;
 946
 947 out_delete_evlist:
 948         perf_evlist__delete(session->evlist);
 949         session->evlist = NULL;
 950         return -ENOMEM;
 951 }
 952
 953 int perf_event__synthesize_attr(struct perf_event_attr *attr, u16 ids, u64 *id,
 954                                 perf_event__handler_t process,
 955                                 struct perf_session *session)
 956 {
 957         union perf_event *ev;
 958         size_t size;
 959         int err;
 960
 961         size = sizeof(struct perf_event_attr);
 962         size = ALIGN(size, sizeof(u64));
 963         size += sizeof(struct perf_event_header);
 964         size += ids * sizeof(u64);
 965
 966         ev = malloc(size);
 967
 968         if (ev == NULL)
 969                 return -ENOMEM;
 970
 971         ev->attr.attr = *attr;
 972         memcpy(ev->attr.id, id, ids * sizeof(u64));
 973
 974         ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
 975         ev->attr.header.size = size;
 976
 977         err = process(ev, NULL, session);
 978
 979         free(ev);
 980
 981         return err;
 982 }
 983
 984 int perf_session__synthesize_attrs(struct perf_session *session,
 985                                    perf_event__handler_t process)
 986 {
 987         struct perf_evsel *attr;
 988         int err = 0;
 989
 990         list_for_each_entry(attr, &session->evlist->entries, node) {
 991                 err = perf_event__synthesize_attr(&attr->attr, attr->ids,
 992                                                   attr->id, process, session);
 993                 if (err) {
 994                         pr_debug("failed to create perf header attribute\n");
 995                         return err;
 996                 }
 997         }
 998
 999         return err;
1000 }
1001
1002 int perf_event__process_attr(union perf_event *event,
1003                              struct perf_session *session)
1004 {
1005         unsigned int i, ids, n_ids;
1006         struct perf_evsel *evsel;
1007
1008         if (session->evlist == NULL) {
1009                 session->evlist = perf_evlist__new(NULL, NULL);
1010                 if (session->evlist == NULL)
1011                         return -ENOMEM;
1012         }
1013
1014         evsel = perf_evsel__new(&event->attr.attr,
1015                                 session->evlist->nr_entries);
1016         if (evsel == NULL)
1017                 return -ENOMEM;
1018
1019         perf_evlist__add(session->evlist, evsel);
1020
1021         ids = event->header.size;
1022         ids -= (void *)&event->attr.id - (void *)event;
1023         n_ids = ids / sizeof(u64);
1024         /*
1025          * We don't have the cpu and thread maps on the header, so
1026          * for allocating the perf_sample_id table we fake 1 cpu and
1027          * hattr->ids threads.
1028          */
1029         if (perf_evsel__alloc_id(evsel, 1, n_ids))
1030                 return -ENOMEM;
1031
1032         for (i = 0; i < n_ids; i++) {
1033                 perf_evlist__id_add(session->evlist, evsel, 0, i,
1034                                     event->attr.id[i]);
1035         }
1036
1037         perf_session__update_sample_type(session);
1038
1039         return 0;
1040 }
1041
1042 int perf_event__synthesize_event_type(u64 event_id, char *name,
1043                                       perf_event__handler_t process,
1044                                       struct perf_session *session)
1045 {
1046         union perf_event ev;
1047         size_t size = 0;
1048         int err = 0;
1049
1050         memset(&ev, 0, sizeof(ev));
1051
1052         ev.event_type.event_type.event_id = event_id;
1053         memset(ev.event_type.event_type.name, 0, MAX_EVENT_NAME);
1054         strncpy(ev.event_type.event_type.name, name, MAX_EVENT_NAME - 1);
1055
1056         ev.event_type.header.type = PERF_RECORD_HEADER_EVENT_TYPE;
1057         size = strlen(name);
1058         size = ALIGN(size, sizeof(u64));
1059         ev.event_type.header.size = sizeof(ev.event_type) -
1060                 (sizeof(ev.event_type.event_type.name) - size);
1061
1062         err = process(&ev, NULL, session);
1063
1064         return err;
1065 }
1066
1067 int perf_event__synthesize_event_types(perf_event__handler_t process,
1068                                        struct perf_session *session)
1069 {
1070         struct perf_trace_event_type *type;
1071         int i, err = 0;
1072
1073         for (i = 0; i < event_count; i++) {
1074                 type = &events[i];
1075
1076                 err = perf_event__synthesize_event_type(type->event_id,
1077                                                         type->name, process,
1078                                                         session);
1079                 if (err) {
1080                         pr_debug("failed to create perf header event type\n");
1081                         return err;
1082                 }
1083         }
1084
1085         return err;
1086 }
1087
1088 int perf_event__process_event_type(union perf_event *event,
1089                                    struct perf_session *session __unused)
1090 {
1091         if (perf_header__push_event(event->event_type.event_type.event_id,
1092                                     event->event_type.event_type.name) < 0)
1093                 return -ENOMEM;
1094
1095         return 0;
1096 }
1097
1098 int perf_event__synthesize_tracing_data(int fd, struct perf_evlist *evlist,
1099                                          perf_event__handler_t process,
1100                                    struct perf_session *session __unused)
1101 {
1102         union perf_event ev;
1103         ssize_t size = 0, aligned_size = 0, padding;
1104         int err __used = 0;
1105
1106         memset(&ev, 0, sizeof(ev));
1107
1108         ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
1109         size = read_tracing_data_size(fd, &evlist->entries);
1110         if (size <= 0)
1111                 return size;
1112         aligned_size = ALIGN(size, sizeof(u64));
1113         padding = aligned_size - size;
1114         ev.tracing_data.header.size = sizeof(ev.tracing_data);
1115         ev.tracing_data.size = aligned_size;
1116
1117         process(&ev, NULL, session);
1118
1119         err = read_tracing_data(fd, &evlist->entries);
1120         write_padded(fd, NULL, 0, padding);
1121
1122         return aligned_size;
1123 }
1124
1125 int perf_event__process_tracing_data(union perf_event *event,
1126                                      struct perf_session *session)
1127 {
1128         ssize_t size_read, padding, size = event->tracing_data.size;
1129         off_t offset = lseek(session->fd, 0, SEEK_CUR);
1130         char buf[BUFSIZ];
1131
1132         /* setup for reading amidst mmap */
1133         lseek(session->fd, offset + sizeof(struct tracing_data_event),
1134               SEEK_SET);
1135
1136         size_read = trace_report(session->fd, session->repipe);
1137
1138         padding = ALIGN(size_read, sizeof(u64)) - size_read;
1139
1140         if (read(session->fd, buf, padding) < 0)
1141                 die("reading input file");
1142         if (session->repipe) {
1143                 int retw = write(STDOUT_FILENO, buf, padding);
1144                 if (retw <= 0 || retw != padding)
1145                         die("repiping tracing data padding");
1146         }
1147
1148         if (size_read + padding != size)
1149                 die("tracing data size mismatch");
1150
1151         return size_read + padding;
1152 }
1153
1154 int perf_event__synthesize_build_id(struct dso *pos, u16 misc,
1155                                     perf_event__handler_t process,
1156                                     struct machine *machine,
1157                                     struct perf_session *session)
1158 {
1159         union perf_event ev;
1160         size_t len;
1161         int err = 0;
1162
1163         if (!pos->hit)
1164                 return err;
1165
1166         memset(&ev, 0, sizeof(ev));
1167
1168         len = pos->long_name_len + 1;
1169         len = ALIGN(len, NAME_ALIGN);
1170         memcpy(&ev.build_id.build_id, pos->build_id, sizeof(pos->build_id));
1171         ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
1172         ev.build_id.header.misc = misc;
1173         ev.build_id.pid = machine->pid;
1174         ev.build_id.header.size = sizeof(ev.build_id) + len;
1175         memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);
1176
1177         err = process(&ev, NULL, session);
1178
1179         return err;
1180 }
1181
1182 int perf_event__process_build_id(union perf_event *event,
1183                                  struct perf_session *session)
1184 {
1185         __event_process_build_id(&event->build_id,
1186                                  event->build_id.filename,
1187                                  session);
1188         return 0;
1189 }
1190
1191 void disable_buildid_cache(void)
1192 {
1193         no_buildid_cache = true;
1194 }