tools/perf/util/header.c

   1 #include <sys/types.h>
   2 #include <byteswap.h>
   3 #include <unistd.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <linux/list.h>
   7 #include <linux/kernel.h>
   8
   9 #include "util.h"
  10 #include "header.h"
  11 #include "../perf.h"
  12 #include "trace-event.h"
  13 #include "session.h"
  14 #include "symbol.h"
  15 #include "debug.h"
  16
  17 /*
  18  * Create new perf.data header attribute:
  19  */
  20 struct perf_header_attr *perf_header_attr__new(struct perf_event_attr *attr)
  21 {
  22         struct perf_header_attr *self = malloc(sizeof(*self));
  23
  24         if (self != NULL) {
  25                 self->attr = *attr;
  26                 self->ids  = 0;
  27                 self->size = 1;
  28                 self->id   = malloc(sizeof(u64));
  29                 if (self->id == NULL) {
  30                         free(self);
  31                         self = NULL;
  32                 }
  33         }
  34
  35         return self;
  36 }
  37
  38 void perf_header_attr__delete(struct perf_header_attr *self)
  39 {
  40         free(self->id);
  41         free(self);
  42 }
  43
  44 int perf_header_attr__add_id(struct perf_header_attr *self, u64 id)
  45 {
  46         int pos = self->ids;
  47
  48         self->ids++;
  49         if (self->ids > self->size) {
  50                 int nsize = self->size * 2;
  51                 u64 *nid = realloc(self->id, nsize * sizeof(u64));
  52
  53                 if (nid == NULL)
  54                         return -1;
  55
  56                 self->size = nsize;
  57                 self->id = nid;
  58         }
  59         self->id[pos] = id;
  60         return 0;
  61 }
  62
  63 int perf_header__init(struct perf_header *self)
  64 {
  65         self->size = 1;
  66         self->attr = malloc(sizeof(void *));
  67         return self->attr == NULL ? -ENOMEM : 0;
  68 }
  69
  70 void perf_header__exit(struct perf_header *self)
  71 {
  72         int i;
  73         for (i = 0; i < self->attrs; ++i)
  74                 perf_header_attr__delete(self->attr[i]);
  75         free(self->attr);
  76 }
  77
  78 int perf_header__add_attr(struct perf_header *self,
  79                           struct perf_header_attr *attr)
  80 {
  81         if (self->frozen)
  82                 return -1;
  83
  84         if (self->attrs == self->size) {
  85                 int nsize = self->size * 2;
  86                 struct perf_header_attr **nattr;
  87
  88                 nattr = realloc(self->attr, nsize * sizeof(void *));
  89                 if (nattr == NULL)
  90                         return -1;
  91
  92                 self->size = nsize;
  93                 self->attr = nattr;
  94         }
  95
  96         self->attr[self->attrs++] = attr;
  97         return 0;
  98 }
  99
 100 #define MAX_EVENT_NAME 64
 101
 102 struct perf_trace_event_type {
 103         u64     event_id;
 104         char    name[MAX_EVENT_NAME];
 105 };
 106
 107 static int event_count;
 108 static struct perf_trace_event_type *events;
 109
 110 int perf_header__push_event(u64 id, const char *name)
 111 {
 112         if (strlen(name) > MAX_EVENT_NAME)
 113                 pr_warning("Event %s will be truncated\n", name);
 114
 115         if (!events) {
 116                 events = malloc(sizeof(struct perf_trace_event_type));
 117                 if (events == NULL)
 118                         return -ENOMEM;
 119         } else {
 120                 struct perf_trace_event_type *nevents;
 121
 122                 nevents = realloc(events, (event_count + 1) * sizeof(*events));
 123                 if (nevents == NULL)
 124                         return -ENOMEM;
 125                 events = nevents;
 126         }
 127         memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
 128         events[event_count].event_id = id;
 129         strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
 130         event_count++;
 131         return 0;
 132 }
 133
 134 char *perf_header__find_event(u64 id)
 135 {
 136         int i;
 137         for (i = 0 ; i < event_count; i++) {
 138                 if (events[i].event_id == id)
 139                         return events[i].name;
 140         }
 141         return NULL;
 142 }
 143
 144 static const char *__perf_magic = "PERFFILE";
 145
 146 #define PERF_MAGIC      (*(u64 *)__perf_magic)
 147
 148 struct perf_file_attr {
 149         struct perf_event_attr  attr;
 150         struct perf_file_section        ids;
 151 };
 152
 153 void perf_header__set_feat(struct perf_header *self, int feat)
 154 {
 155         set_bit(feat, self->adds_features);
 156 }
 157
 158 bool perf_header__has_feat(const struct perf_header *self, int feat)
 159 {
 160         return test_bit(feat, self->adds_features);
 161 }
 162
 163 static int do_write(int fd, const void *buf, size_t size)
 164 {
 165         while (size) {
 166                 int ret = write(fd, buf, size);
 167
 168                 if (ret < 0)
 169                         return -errno;
 170
 171                 size -= ret;
 172                 buf += ret;
 173         }
 174
 175         return 0;
 176 }
 177
 178 #define NAME_ALIGN 64
 179
 180 static int write_padded(int fd, const void *bf, size_t count,
 181                         size_t count_aligned)
 182 {
 183         static const char zero_buf[NAME_ALIGN];
 184         int err = do_write(fd, bf, count);
 185
 186         if (!err)
 187                 err = do_write(fd, zero_buf, count_aligned - count);
 188
 189         return err;
 190 }
 191
 192 #define dsos__for_each_with_build_id(pos, head) \
 193         list_for_each_entry(pos, head, node)    \
 194                 if (!pos->has_build_id)         \
 195                         continue;               \
 196                 else
 197
 198 static int __dsos__write_buildid_table(struct list_head *head, u16 misc, int fd)
 199 {
 200         struct dso *pos;
 201
 202         dsos__for_each_with_build_id(pos, head) {
 203                 int err;
 204                 struct build_id_event b;
 205                 size_t len = pos->long_name_len + 1;
 206
 207                 len = ALIGN(len, NAME_ALIGN);
 208                 memset(&b, 0, sizeof(b));
 209                 memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
 210                 b.header.misc = misc;
 211                 b.header.size = sizeof(b) + len;
 212                 err = do_write(fd, &b, sizeof(b));
 213                 if (err < 0)
 214                         return err;
 215                 err = write_padded(fd, pos->long_name,
 216                                    pos->long_name_len + 1, len);
 217                 if (err < 0)
 218                         return err;
 219         }
 220
 221         return 0;
 222 }
 223
 224 static int dsos__write_buildid_table(int fd)
 225 {
 226         int err = __dsos__write_buildid_table(&dsos__kernel,
 227                                               PERF_RECORD_MISC_KERNEL, fd);
 228         if (err == 0)
 229                 err = __dsos__write_buildid_table(&dsos__user,
 230                                                   PERF_RECORD_MISC_USER, fd);
 231         return err;
 232 }
 233
 234 static int dso__cache_build_id(struct dso *self, const char *debugdir)
 235 {
 236         const size_t size = PATH_MAX;
 237         char *filename = malloc(size),
 238              *linkname = malloc(size), *targetname, *sbuild_id;
 239         int len, err = -1;
 240         bool is_kallsyms = self->kernel && self->long_name[0] != '/';
 241
 242         if (filename == NULL || linkname == NULL)
 243                 goto out_free;
 244
 245         len = snprintf(filename, size, "%s%s%s",
 246                        debugdir, is_kallsyms ? "/" : "", self->long_name);
 247         if (mkdir_p(filename, 0755))
 248                 goto out_free;
 249
 250         len += snprintf(filename + len, sizeof(filename) - len, "/");
 251         sbuild_id = filename + len;
 252         build_id__sprintf(self->build_id, sizeof(self->build_id), sbuild_id);
 253
 254         if (access(filename, F_OK)) {
 255                 if (is_kallsyms) {
 256                          if (copyfile("/proc/kallsyms", filename))
 257                                 goto out_free;
 258                 } else if (link(self->long_name, filename) &&
 259                            copyfile(self->long_name, filename))
 260                         goto out_free;
 261         }
 262
 263         len = snprintf(linkname, size, "%s/.build-id/%.2s",
 264                        debugdir, sbuild_id);
 265
 266         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 267                 goto out_free;
 268
 269         snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
 270         targetname = filename + strlen(debugdir) - 5;
 271         memcpy(targetname, "../..", 5);
 272
 273         if (symlink(targetname, linkname) == 0)
 274                 err = 0;
 275 out_free:
 276         free(filename);
 277         free(linkname);
 278         return err;
 279 }
 280
 281 static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
 282 {
 283         struct dso *pos;
 284         int err = 0;
 285
 286         dsos__for_each_with_build_id(pos, head)
 287                 if (dso__cache_build_id(pos, debugdir))
 288                         err = -1;
 289
 290         return err;
 291 }
 292
 293 static int dsos__cache_build_ids(void)
 294 {
 295         int err_kernel, err_user;
 296         char debugdir[PATH_MAX];
 297
 298         snprintf(debugdir, sizeof(debugdir), "%s/%s", getenv("HOME"),
 299                  DEBUG_CACHE_DIR);
 300
 301         if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
 302                 return -1;
 303
 304         err_kernel = __dsos__cache_build_ids(&dsos__kernel, debugdir);
 305         err_user   = __dsos__cache_build_ids(&dsos__user, debugdir);
 306         return err_kernel || err_user ? -1 : 0;
 307 }
 308
 309 static int perf_header__adds_write(struct perf_header *self, int fd)
 310 {
 311         int nr_sections;
 312         struct perf_file_section *feat_sec;
 313         int sec_size;
 314         u64 sec_start;
 315         int idx = 0, err;
 316
 317         if (dsos__read_build_ids())
 318                 perf_header__set_feat(self, HEADER_BUILD_ID);
 319
 320         nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
 321         if (!nr_sections)
 322                 return 0;
 323
 324         feat_sec = calloc(sizeof(*feat_sec), nr_sections);
 325         if (feat_sec == NULL)
 326                 return -ENOMEM;
 327
 328         sec_size = sizeof(*feat_sec) * nr_sections;
 329
 330         sec_start = self->data_offset + self->data_size;
 331         lseek(fd, sec_start + sec_size, SEEK_SET);
 332
 333         if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
 334                 struct perf_file_section *trace_sec;
 335
 336                 trace_sec = &feat_sec[idx++];
 337
 338                 /* Write trace info */
 339                 trace_sec->offset = lseek(fd, 0, SEEK_CUR);
 340                 read_tracing_data(fd, attrs, nr_counters);
 341                 trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
 342         }
 343
 344
 345         if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
 346                 struct perf_file_section *buildid_sec;
 347
 348                 buildid_sec = &feat_sec[idx++];
 349
 350                 /* Write build-ids */
 351                 buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
 352                 err = dsos__write_buildid_table(fd);
 353                 if (err < 0) {
 354                         pr_debug("failed to write buildid table\n");
 355                         goto out_free;
 356                 }
 357                 buildid_sec->size = lseek(fd, 0, SEEK_CUR) - buildid_sec->offset;
 358                 dsos__cache_build_ids();
 359         }
 360
 361         lseek(fd, sec_start, SEEK_SET);
 362         err = do_write(fd, feat_sec, sec_size);
 363         if (err < 0)
 364                 pr_debug("failed to write feature section\n");
 365 out_free:
 366         free(feat_sec);
 367         return err;
 368 }
 369
 370 int perf_header__write(struct perf_header *self, int fd, bool at_exit)
 371 {
 372         struct perf_file_header f_header;
 373         struct perf_file_attr   f_attr;
 374         struct perf_header_attr *attr;
 375         int i, err;
 376
 377         lseek(fd, sizeof(f_header), SEEK_SET);
 378
 379
 380         for (i = 0; i < self->attrs; i++) {
 381                 attr = self->attr[i];
 382
 383                 attr->id_offset = lseek(fd, 0, SEEK_CUR);
 384                 err = do_write(fd, attr->id, attr->ids * sizeof(u64));
 385                 if (err < 0) {
 386                         pr_debug("failed to write perf header\n");
 387                         return err;
 388                 }
 389         }
 390
 391
 392         self->attr_offset = lseek(fd, 0, SEEK_CUR);
 393
 394         for (i = 0; i < self->attrs; i++) {
 395                 attr = self->attr[i];
 396
 397                 f_attr = (struct perf_file_attr){
 398                         .attr = attr->attr,
 399                         .ids  = {
 400                                 .offset = attr->id_offset,
 401                                 .size   = attr->ids * sizeof(u64),
 402                         }
 403                 };
 404                 err = do_write(fd, &f_attr, sizeof(f_attr));
 405                 if (err < 0) {
 406                         pr_debug("failed to write perf header attribute\n");
 407                         return err;
 408                 }
 409         }
 410
 411         self->event_offset = lseek(fd, 0, SEEK_CUR);
 412         self->event_size = event_count * sizeof(struct perf_trace_event_type);
 413         if (events) {
 414                 err = do_write(fd, events, self->event_size);
 415                 if (err < 0) {
 416                         pr_debug("failed to write perf header events\n");
 417                         return err;
 418                 }
 419         }
 420
 421         self->data_offset = lseek(fd, 0, SEEK_CUR);
 422
 423         if (at_exit) {
 424                 err = perf_header__adds_write(self, fd);
 425                 if (err < 0)
 426                         return err;
 427         }
 428
 429         f_header = (struct perf_file_header){
 430                 .magic     = PERF_MAGIC,
 431                 .size      = sizeof(f_header),
 432                 .attr_size = sizeof(f_attr),
 433                 .attrs = {
 434                         .offset = self->attr_offset,
 435                         .size   = self->attrs * sizeof(f_attr),
 436                 },
 437                 .data = {
 438                         .offset = self->data_offset,
 439                         .size   = self->data_size,
 440                 },
 441                 .event_types = {
 442                         .offset = self->event_offset,
 443                         .size   = self->event_size,
 444                 },
 445         };
 446
 447         memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));
 448
 449         lseek(fd, 0, SEEK_SET);
 450         err = do_write(fd, &f_header, sizeof(f_header));
 451         if (err < 0) {
 452                 pr_debug("failed to write perf header\n");
 453                 return err;
 454         }
 455         lseek(fd, self->data_offset + self->data_size, SEEK_SET);
 456
 457         self->frozen = 1;
 458         return 0;
 459 }
 460
 461 static int do_read(int fd, void *buf, size_t size)
 462 {
 463         while (size) {
 464                 int ret = read(fd, buf, size);
 465
 466                 if (ret <= 0)
 467                         return -1;
 468
 469                 size -= ret;
 470                 buf += ret;
 471         }
 472
 473         return 0;
 474 }
 475
 476 static int perf_header__getbuffer64(struct perf_header *self,
 477                                     int fd, void *buf, size_t size)
 478 {
 479         if (do_read(fd, buf, size))
 480                 return -1;
 481
 482         if (self->needs_swap)
 483                 mem_bswap_64(buf, size);
 484
 485         return 0;
 486 }
 487
 488 int perf_header__process_sections(struct perf_header *self, int fd,
 489                                   int (*process)(struct perf_file_section *self,
 490                                                  struct perf_header *ph,
 491                                                  int feat, int fd))
 492 {
 493         struct perf_file_section *feat_sec;
 494         int nr_sections;
 495         int sec_size;
 496         int idx = 0;
 497         int err = -1, feat = 1;
 498
 499         nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
 500         if (!nr_sections)
 501                 return 0;
 502
 503         feat_sec = calloc(sizeof(*feat_sec), nr_sections);
 504         if (!feat_sec)
 505                 return -1;
 506
 507         sec_size = sizeof(*feat_sec) * nr_sections;
 508
 509         lseek(fd, self->data_offset + self->data_size, SEEK_SET);
 510
 511         if (perf_header__getbuffer64(self, fd, feat_sec, sec_size))
 512                 goto out_free;
 513
 514         err = 0;
 515         while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
 516                 if (perf_header__has_feat(self, feat)) {
 517                         struct perf_file_section *sec = &feat_sec[idx++];
 518
 519                         err = process(sec, self, feat, fd);
 520                         if (err < 0)
 521                                 break;
 522                 }
 523                 ++feat;
 524         }
 525 out_free:
 526         free(feat_sec);
 527         return err;
 528 }
 529
 530 int perf_file_header__read(struct perf_file_header *self,
 531                            struct perf_header *ph, int fd)
 532 {
 533         lseek(fd, 0, SEEK_SET);
 534
 535         if (do_read(fd, self, sizeof(*self)) ||
 536             memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
 537                 return -1;
 538
 539         if (self->attr_size != sizeof(struct perf_file_attr)) {
 540                 u64 attr_size = bswap_64(self->attr_size);
 541
 542                 if (attr_size != sizeof(struct perf_file_attr))
 543                         return -1;
 544
 545                 mem_bswap_64(self, offsetof(struct perf_file_header,
 546                                             adds_features));
 547                 ph->needs_swap = true;
 548         }
 549
 550         if (self->size != sizeof(*self)) {
 551                 /* Support the previous format */
 552                 if (self->size == offsetof(typeof(*self), adds_features))
 553                         bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
 554                 else
 555                         return -1;
 556         }
 557
 558         memcpy(&ph->adds_features, &self->adds_features,
 559                sizeof(ph->adds_features));
 560         /*
 561          * FIXME: hack that assumes that if we need swap the perf.data file
 562          * may be coming from an arch with a different word-size, ergo different
 563          * DEFINE_BITMAP format, investigate more later, but for now its mostly
 564          * safe to assume that we have a build-id section. Trace files probably
 565          * have several other issues in this realm anyway...
 566          */
 567         if (ph->needs_swap) {
 568                 memset(&ph->adds_features, 0, sizeof(ph->adds_features));
 569                 perf_header__set_feat(ph, HEADER_BUILD_ID);
 570         }
 571
 572         ph->event_offset = self->event_types.offset;
 573         ph->event_size   = self->event_types.size;
 574         ph->data_offset  = self->data.offset;
 575         ph->data_size    = self->data.size;
 576         return 0;
 577 }
 578
 579 static int perf_file_section__process(struct perf_file_section *self,
 580                                       struct perf_header *ph,
 581                                       int feat, int fd)
 582 {
 583         if (lseek(fd, self->offset, SEEK_SET) < 0) {
 584                 pr_debug("Failed to lseek to %Ld offset for feature %d, "
 585                          "continuing...\n", self->offset, feat);
 586                 return 0;
 587         }
 588
 589         switch (feat) {
 590         case HEADER_TRACE_INFO:
 591                 trace_report(fd);
 592                 break;
 593
 594         case HEADER_BUILD_ID:
 595                 if (perf_header__read_build_ids(ph, fd, self->offset, self->size))
 596                         pr_debug("Failed to read buildids, continuing...\n");
 597                 break;
 598         default:
 599                 pr_debug("unknown feature %d, continuing...\n", feat);
 600         }
 601
 602         return 0;
 603 }
 604
 605 int perf_header__read(struct perf_header *self, int fd)
 606 {
 607         struct perf_file_header f_header;
 608         struct perf_file_attr   f_attr;
 609         u64                     f_id;
 610         int nr_attrs, nr_ids, i, j;
 611
 612         if (perf_file_header__read(&f_header, self, fd) < 0) {
 613                 pr_debug("incompatible file format\n");
 614                 return -EINVAL;
 615         }
 616
 617         nr_attrs = f_header.attrs.size / sizeof(f_attr);
 618         lseek(fd, f_header.attrs.offset, SEEK_SET);
 619
 620         for (i = 0; i < nr_attrs; i++) {
 621                 struct perf_header_attr *attr;
 622                 off_t tmp;
 623
 624                 if (perf_header__getbuffer64(self, fd, &f_attr, sizeof(f_attr)))
 625                         goto out_errno;
 626
 627                 tmp = lseek(fd, 0, SEEK_CUR);
 628
 629                 attr = perf_header_attr__new(&f_attr.attr);
 630                 if (attr == NULL)
 631                          return -ENOMEM;
 632
 633                 nr_ids = f_attr.ids.size / sizeof(u64);
 634                 lseek(fd, f_attr.ids.offset, SEEK_SET);
 635
 636                 for (j = 0; j < nr_ids; j++) {
 637                         if (perf_header__getbuffer64(self, fd, &f_id, sizeof(f_id)))
 638                                 goto out_errno;
 639
 640                         if (perf_header_attr__add_id(attr, f_id) < 0) {
 641                                 perf_header_attr__delete(attr);
 642                                 return -ENOMEM;
 643                         }
 644                 }
 645                 if (perf_header__add_attr(self, attr) < 0) {
 646                         perf_header_attr__delete(attr);
 647                         return -ENOMEM;
 648                 }
 649
 650                 lseek(fd, tmp, SEEK_SET);
 651         }
 652
 653         if (f_header.event_types.size) {
 654                 lseek(fd, f_header.event_types.offset, SEEK_SET);
 655                 events = malloc(f_header.event_types.size);
 656                 if (events == NULL)
 657                         return -ENOMEM;
 658                 if (perf_header__getbuffer64(self, fd, events,
 659                                              f_header.event_types.size))
 660                         goto out_errno;
 661                 event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
 662         }
 663
 664         perf_header__process_sections(self, fd, perf_file_section__process);
 665
 666         lseek(fd, self->data_offset, SEEK_SET);
 667
 668         self->frozen = 1;
 669         return 0;
 670 out_errno:
 671         return -errno;
 672 }
 673
 674 u64 perf_header__sample_type(struct perf_header *header)
 675 {
 676         u64 type = 0;
 677         int i;
 678
 679         for (i = 0; i < header->attrs; i++) {
 680                 struct perf_header_attr *attr = header->attr[i];
 681
 682                 if (!type)
 683                         type = attr->attr.sample_type;
 684                 else if (type != attr->attr.sample_type)
 685                         die("non matching sample_type");
 686         }
 687
 688         return type;
 689 }
 690
 691 struct perf_event_attr *
 692 perf_header__find_attr(u64 id, struct perf_header *header)
 693 {
 694         int i;
 695
 696         for (i = 0; i < header->attrs; i++) {
 697                 struct perf_header_attr *attr = header->attr[i];
 698                 int j;
 699
 700                 for (j = 0; j < attr->ids; j++) {
 701                         if (attr->id[j] == id)
 702                                 return &attr->attr;
 703                 }
 704         }
 705
 706         return NULL;
 707 }