tools/perf/util/trace-event-info.c

   1 /*
   2  * Copyright (C) 2008,2009, Steven Rostedt <[email protected]>
   3  *
   4  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License (not later!)
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  20  */
  21 #include "util.h"
  22 #include <dirent.h>
  23 #include <mntent.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <stdarg.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <sys/wait.h>
  31 #include <pthread.h>
  32 #include <fcntl.h>
  33 #include <unistd.h>
  34 #include <errno.h>
  35 #include <stdbool.h>
  36 #include <linux/list.h>
  37 #include <linux/kernel.h>
  38
  39 #include "../perf.h"
  40 #include "trace-event.h"
  41 #include <api/fs/tracing_path.h>
  42 #include "evsel.h"
  43 #include "debug.h"
  44
  45 #define VERSION "0.6"
  46
  47 static int output_fd;
  48
  49
  50 int bigendian(void)
  51 {
  52         unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
  53         unsigned int *ptr;
  54
  55         ptr = (unsigned int *)(void *)str;
  56         return *ptr == 0x01020304;
  57 }
  58
  59 /* unfortunately, you can not stat debugfs or proc files for size */
  60 static int record_file(const char *file, ssize_t hdr_sz)
  61 {
  62         unsigned long long size = 0;
  63         char buf[BUFSIZ], *sizep;
  64         off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
  65         int r, fd;
  66         int err = -EIO;
  67
  68         fd = open(file, O_RDONLY);
  69         if (fd < 0) {
  70                 pr_debug("Can't read '%s'", file);
  71                 return -errno;
  72         }
  73
  74         /* put in zeros for file size, then fill true size later */
  75         if (hdr_sz) {
  76                 if (write(output_fd, &size, hdr_sz) != hdr_sz)
  77                         goto out;
  78         }
  79
  80         do {
  81                 r = read(fd, buf, BUFSIZ);
  82                 if (r > 0) {
  83                         size += r;
  84                         if (write(output_fd, buf, r) != r)
  85                                 goto out;
  86                 }
  87         } while (r > 0);
  88
  89         /* ugh, handle big-endian hdr_size == 4 */
  90         sizep = (char*)&size;
  91         if (bigendian())
  92                 sizep += sizeof(u64) - hdr_sz;
  93
  94         if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
  95                 pr_debug("writing file size failed\n");
  96                 goto out;
  97         }
  98
  99         err = 0;
 100 out:
 101         close(fd);
 102         return err;
 103 }
 104
 105 static int record_header_files(void)
 106 {
 107         char *path;
 108         struct stat st;
 109         int err = -EIO;
 110
 111         path = get_tracing_file("events/header_page");
 112         if (!path) {
 113                 pr_debug("can't get tracing/events/header_page");
 114                 return -ENOMEM;
 115         }
 116
 117         if (stat(path, &st) < 0) {
 118                 pr_debug("can't read '%s'", path);
 119                 goto out;
 120         }
 121
 122         if (write(output_fd, "header_page", 12) != 12) {
 123                 pr_debug("can't write header_page\n");
 124                 goto out;
 125         }
 126
 127         if (record_file(path, 8) < 0) {
 128                 pr_debug("can't record header_page file\n");
 129                 goto out;
 130         }
 131
 132         put_tracing_file(path);
 133
 134         path = get_tracing_file("events/header_event");
 135         if (!path) {
 136                 pr_debug("can't get tracing/events/header_event");
 137                 err = -ENOMEM;
 138                 goto out;
 139         }
 140
 141         if (stat(path, &st) < 0) {
 142                 pr_debug("can't read '%s'", path);
 143                 goto out;
 144         }
 145
 146         if (write(output_fd, "header_event", 13) != 13) {
 147                 pr_debug("can't write header_event\n");
 148                 goto out;
 149         }
 150
 151         if (record_file(path, 8) < 0) {
 152                 pr_debug("can't record header_event file\n");
 153                 goto out;
 154         }
 155
 156         err = 0;
 157 out:
 158         put_tracing_file(path);
 159         return err;
 160 }
 161
 162 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
 163 {
 164         while (tps) {
 165                 if (!strcmp(sys, tps->name))
 166                         return true;
 167                 tps = tps->next;
 168         }
 169
 170         return false;
 171 }
 172
 173 #define for_each_event(dir, dent, tps)                          \
 174         while ((dent = readdir(dir)))                           \
 175                 if (dent->d_type == DT_DIR &&                   \
 176                     (strcmp(dent->d_name, ".")) &&              \
 177                     (strcmp(dent->d_name, "..")))               \
 178
 179 static int copy_event_system(const char *sys, struct tracepoint_path *tps)
 180 {
 181         struct dirent *dent;
 182         struct stat st;
 183         char *format;
 184         DIR *dir;
 185         int count = 0;
 186         int ret;
 187         int err;
 188
 189         dir = opendir(sys);
 190         if (!dir) {
 191                 pr_debug("can't read directory '%s'", sys);
 192                 return -errno;
 193         }
 194
 195         for_each_event(dir, dent, tps) {
 196                 if (!name_in_tp_list(dent->d_name, tps))
 197                         continue;
 198
 199                 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
 200                         err = -ENOMEM;
 201                         goto out;
 202                 }
 203                 ret = stat(format, &st);
 204                 free(format);
 205                 if (ret < 0)
 206                         continue;
 207                 count++;
 208         }
 209
 210         if (write(output_fd, &count, 4) != 4) {
 211                 err = -EIO;
 212                 pr_debug("can't write count\n");
 213                 goto out;
 214         }
 215
 216         rewinddir(dir);
 217         for_each_event(dir, dent, tps) {
 218                 if (!name_in_tp_list(dent->d_name, tps))
 219                         continue;
 220
 221                 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
 222                         err = -ENOMEM;
 223                         goto out;
 224                 }
 225                 ret = stat(format, &st);
 226
 227                 if (ret >= 0) {
 228                         err = record_file(format, 8);
 229                         if (err) {
 230                                 free(format);
 231                                 goto out;
 232                         }
 233                 }
 234                 free(format);
 235         }
 236         err = 0;
 237 out:
 238         closedir(dir);
 239         return err;
 240 }
 241
 242 static int record_ftrace_files(struct tracepoint_path *tps)
 243 {
 244         char *path;
 245         int ret;
 246
 247         path = get_tracing_file("events/ftrace");
 248         if (!path) {
 249                 pr_debug("can't get tracing/events/ftrace");
 250                 return -ENOMEM;
 251         }
 252
 253         ret = copy_event_system(path, tps);
 254
 255         put_tracing_file(path);
 256
 257         return ret;
 258 }
 259
 260 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
 261 {
 262         while (tps) {
 263                 if (!strcmp(sys, tps->system))
 264                         return true;
 265                 tps = tps->next;
 266         }
 267
 268         return false;
 269 }
 270
 271 static int record_event_files(struct tracepoint_path *tps)
 272 {
 273         struct dirent *dent;
 274         struct stat st;
 275         char *path;
 276         char *sys;
 277         DIR *dir;
 278         int count = 0;
 279         int ret;
 280         int err;
 281
 282         path = get_tracing_file("events");
 283         if (!path) {
 284                 pr_debug("can't get tracing/events");
 285                 return -ENOMEM;
 286         }
 287
 288         dir = opendir(path);
 289         if (!dir) {
 290                 err = -errno;
 291                 pr_debug("can't read directory '%s'", path);
 292                 goto out;
 293         }
 294
 295         for_each_event(dir, dent, tps) {
 296                 if (strcmp(dent->d_name, "ftrace") == 0 ||
 297                     !system_in_tp_list(dent->d_name, tps))
 298                         continue;
 299
 300                 count++;
 301         }
 302
 303         if (write(output_fd, &count, 4) != 4) {
 304                 err = -EIO;
 305                 pr_debug("can't write count\n");
 306                 goto out;
 307         }
 308
 309         rewinddir(dir);
 310         for_each_event(dir, dent, tps) {
 311                 if (strcmp(dent->d_name, "ftrace") == 0 ||
 312                     !system_in_tp_list(dent->d_name, tps))
 313                         continue;
 314
 315                 if (asprintf(&sys, "%s/%s", path, dent->d_name) < 0) {
 316                         err = -ENOMEM;
 317                         goto out;
 318                 }
 319                 ret = stat(sys, &st);
 320                 if (ret >= 0) {
 321                         ssize_t size = strlen(dent->d_name) + 1;
 322
 323                         if (write(output_fd, dent->d_name, size) != size ||
 324                             copy_event_system(sys, tps) < 0) {
 325                                 err = -EIO;
 326                                 free(sys);
 327                                 goto out;
 328                         }
 329                 }
 330                 free(sys);
 331         }
 332         err = 0;
 333 out:
 334         closedir(dir);
 335         put_tracing_file(path);
 336
 337         return err;
 338 }
 339
 340 static int record_proc_kallsyms(void)
 341 {
 342         unsigned long long size = 0;
 343         /*
 344          * Just to keep older perf.data file parsers happy, record a zero
 345          * sized kallsyms file, i.e. do the same thing that was done when
 346          * /proc/kallsyms (or something specified via --kallsyms, in a
 347          * different path) couldn't be read.
 348          */
 349         return write(output_fd, &size, 4) != 4 ? -EIO : 0;
 350 }
 351
 352 static int record_ftrace_printk(void)
 353 {
 354         unsigned int size;
 355         char *path;
 356         struct stat st;
 357         int ret, err = 0;
 358
 359         path = get_tracing_file("printk_formats");
 360         if (!path) {
 361                 pr_debug("can't get tracing/printk_formats");
 362                 return -ENOMEM;
 363         }
 364
 365         ret = stat(path, &st);
 366         if (ret < 0) {
 367                 /* not found */
 368                 size = 0;
 369                 if (write(output_fd, &size, 4) != 4)
 370                         err = -EIO;
 371                 goto out;
 372         }
 373         err = record_file(path, 4);
 374
 375 out:
 376         put_tracing_file(path);
 377         return err;
 378 }
 379
 380 static int record_saved_cmdline(void)
 381 {
 382         unsigned int size;
 383         char *path;
 384         struct stat st;
 385         int ret, err = 0;
 386
 387         path = get_tracing_file("saved_cmdlines");
 388         if (!path) {
 389                 pr_debug("can't get tracing/saved_cmdline");
 390                 return -ENOMEM;
 391         }
 392
 393         ret = stat(path, &st);
 394         if (ret < 0) {
 395                 /* not found */
 396                 size = 0;
 397                 if (write(output_fd, &size, 8) != 8)
 398                         err = -EIO;
 399                 goto out;
 400         }
 401         err = record_file(path, 8);
 402
 403 out:
 404         put_tracing_file(path);
 405         return err;
 406 }
 407
 408 static void
 409 put_tracepoints_path(struct tracepoint_path *tps)
 410 {
 411         while (tps) {
 412                 struct tracepoint_path *t = tps;
 413
 414                 tps = tps->next;
 415                 zfree(&t->name);
 416                 zfree(&t->system);
 417                 free(t);
 418         }
 419 }
 420
 421 static struct tracepoint_path *
 422 get_tracepoints_path(struct list_head *pattrs)
 423 {
 424         struct tracepoint_path path, *ppath = &path;
 425         struct perf_evsel *pos;
 426         int nr_tracepoints = 0;
 427
 428         list_for_each_entry(pos, pattrs, node) {
 429                 if (pos->attr.type != PERF_TYPE_TRACEPOINT)
 430                         continue;
 431                 ++nr_tracepoints;
 432
 433                 if (pos->name) {
 434                         ppath->next = tracepoint_name_to_path(pos->name);
 435                         if (ppath->next)
 436                                 goto next;
 437
 438                         if (strchr(pos->name, ':') == NULL)
 439                                 goto try_id;
 440
 441                         goto error;
 442                 }
 443
 444 try_id:
 445                 ppath->next = tracepoint_id_to_path(pos->attr.config);
 446                 if (!ppath->next) {
 447 error:
 448                         pr_debug("No memory to alloc tracepoints list\n");
 449                         put_tracepoints_path(&path);
 450                         return NULL;
 451                 }
 452 next:
 453                 ppath = ppath->next;
 454         }
 455
 456         return nr_tracepoints > 0 ? path.next : NULL;
 457 }
 458
 459 bool have_tracepoints(struct list_head *pattrs)
 460 {
 461         struct perf_evsel *pos;
 462
 463         list_for_each_entry(pos, pattrs, node)
 464                 if (pos->attr.type == PERF_TYPE_TRACEPOINT)
 465                         return true;
 466
 467         return false;
 468 }
 469
 470 static int tracing_data_header(void)
 471 {
 472         char buf[20];
 473         ssize_t size;
 474
 475         /* just guessing this is someone's birthday.. ;) */
 476         buf[0] = 23;
 477         buf[1] = 8;
 478         buf[2] = 68;
 479         memcpy(buf + 3, "tracing", 7);
 480
 481         if (write(output_fd, buf, 10) != 10)
 482                 return -1;
 483
 484         size = strlen(VERSION) + 1;
 485         if (write(output_fd, VERSION, size) != size)
 486                 return -1;
 487
 488         /* save endian */
 489         if (bigendian())
 490                 buf[0] = 1;
 491         else
 492                 buf[0] = 0;
 493
 494         if (write(output_fd, buf, 1) != 1)
 495                 return -1;
 496
 497         /* save size of long */
 498         buf[0] = sizeof(long);
 499         if (write(output_fd, buf, 1) != 1)
 500                 return -1;
 501
 502         /* save page_size */
 503         if (write(output_fd, &page_size, 4) != 4)
 504                 return -1;
 505
 506         return 0;
 507 }
 508
 509 struct tracing_data *tracing_data_get(struct list_head *pattrs,
 510                                       int fd, bool temp)
 511 {
 512         struct tracepoint_path *tps;
 513         struct tracing_data *tdata;
 514         int err;
 515
 516         output_fd = fd;
 517
 518         tps = get_tracepoints_path(pattrs);
 519         if (!tps)
 520                 return NULL;
 521
 522         tdata = malloc(sizeof(*tdata));
 523         if (!tdata)
 524                 return NULL;
 525
 526         tdata->temp = temp;
 527         tdata->size = 0;
 528
 529         if (temp) {
 530                 int temp_fd;
 531
 532                 snprintf(tdata->temp_file, sizeof(tdata->temp_file),
 533                          "/tmp/perf-XXXXXX");
 534                 if (!mkstemp(tdata->temp_file)) {
 535                         pr_debug("Can't make temp file");
 536                         return NULL;
 537                 }
 538
 539                 temp_fd = open(tdata->temp_file, O_RDWR);
 540                 if (temp_fd < 0) {
 541                         pr_debug("Can't read '%s'", tdata->temp_file);
 542                         return NULL;
 543                 }
 544
 545                 /*
 546                  * Set the temp file the default output, so all the
 547                  * tracing data are stored into it.
 548                  */
 549                 output_fd = temp_fd;
 550         }
 551
 552         err = tracing_data_header();
 553         if (err)
 554                 goto out;
 555         err = record_header_files();
 556         if (err)
 557                 goto out;
 558         err = record_ftrace_files(tps);
 559         if (err)
 560                 goto out;
 561         err = record_event_files(tps);
 562         if (err)
 563                 goto out;
 564         err = record_proc_kallsyms();
 565         if (err)
 566                 goto out;
 567         err = record_ftrace_printk();
 568         if (err)
 569                 goto out;
 570         err = record_saved_cmdline();
 571
 572 out:
 573         /*
 574          * All tracing data are stored by now, we can restore
 575          * the default output file in case we used temp file.
 576          */
 577         if (temp) {
 578                 tdata->size = lseek(output_fd, 0, SEEK_CUR);
 579                 close(output_fd);
 580                 output_fd = fd;
 581         }
 582
 583         if (err)
 584                 zfree(&tdata);
 585
 586         put_tracepoints_path(tps);
 587         return tdata;
 588 }
 589
 590 int tracing_data_put(struct tracing_data *tdata)
 591 {
 592         int err = 0;
 593
 594         if (tdata->temp) {
 595                 err = record_file(tdata->temp_file, 0);
 596                 unlink(tdata->temp_file);
 597         }
 598
 599         free(tdata);
 600         return err;
 601 }
 602
 603 int read_tracing_data(int fd, struct list_head *pattrs)
 604 {
 605         int err;
 606         struct tracing_data *tdata;
 607
 608         /*
 609          * We work over the real file, so we can write data
 610          * directly, no temp file is needed.
 611          */
 612         tdata = tracing_data_get(pattrs, fd, false);
 613         if (!tdata)
 614                 return -ENOMEM;
 615
 616         err = tracing_data_put(tdata);
 617         return err;
 618 }