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

   1 /*
   2  * Copyright (C) 2008,2009, Steven Rostedt <srostedt@redhat.com>
   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 "0.5"
  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 static int copy_event_system(const char *sys, struct tracepoint_path *tps)
 174 {
 175         struct dirent *dent;
 176         struct stat st;
 177         char *format;
 178         DIR *dir;
 179         int count = 0;
 180         int ret;
 181         int err;
 182
 183         dir = opendir(sys);
 184         if (!dir) {
 185                 pr_debug("can't read directory '%s'", sys);
 186                 return -errno;
 187         }
 188
 189         while ((dent = readdir(dir))) {
 190                 if (dent->d_type != DT_DIR ||
 191                     strcmp(dent->d_name, ".") == 0 ||
 192                     strcmp(dent->d_name, "..") == 0 ||
 193                     !name_in_tp_list(dent->d_name, tps))
 194                         continue;
 195                 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
 196                         err = -ENOMEM;
 197                         goto out;
 198                 }
 199                 ret = stat(format, &st);
 200                 free(format);
 201                 if (ret < 0)
 202                         continue;
 203                 count++;
 204         }
 205
 206         if (write(output_fd, &count, 4) != 4) {
 207                 err = -EIO;
 208                 pr_debug("can't write count\n");
 209                 goto out;
 210         }
 211
 212         rewinddir(dir);
 213         while ((dent = readdir(dir))) {
 214                 if (dent->d_type != DT_DIR ||
 215                     strcmp(dent->d_name, ".") == 0 ||
 216                     strcmp(dent->d_name, "..") == 0 ||
 217                     !name_in_tp_list(dent->d_name, tps))
 218                         continue;
 219                 if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
 220                         err = -ENOMEM;
 221                         goto out;
 222                 }
 223                 ret = stat(format, &st);
 224
 225                 if (ret >= 0) {
 226                         err = record_file(format, 8);
 227                         if (err) {
 228                                 free(format);
 229                                 goto out;
 230                         }
 231                 }
 232                 free(format);
 233         }
 234         err = 0;
 235 out:
 236         closedir(dir);
 237         return err;
 238 }
 239
 240 static int record_ftrace_files(struct tracepoint_path *tps)
 241 {
 242         char *path;
 243         int ret;
 244
 245         path = get_tracing_file("events/ftrace");
 246         if (!path) {
 247                 pr_debug("can't get tracing/events/ftrace");
 248                 return -ENOMEM;
 249         }
 250
 251         ret = copy_event_system(path, tps);
 252
 253         put_tracing_file(path);
 254
 255         return ret;
 256 }
 257
 258 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
 259 {
 260         while (tps) {
 261                 if (!strcmp(sys, tps->system))
 262                         return true;
 263                 tps = tps->next;
 264         }
 265
 266         return false;
 267 }
 268
 269 static int record_event_files(struct tracepoint_path *tps)
 270 {
 271         struct dirent *dent;
 272         struct stat st;
 273         char *path;
 274         char *sys;
 275         DIR *dir;
 276         int count = 0;
 277         int ret;
 278         int err;
 279
 280         path = get_tracing_file("events");
 281         if (!path) {
 282                 pr_debug("can't get tracing/events");
 283                 return -ENOMEM;
 284         }
 285
 286         dir = opendir(path);
 287         if (!dir) {
 288                 err = -errno;
 289                 pr_debug("can't read directory '%s'", path);
 290                 goto out;
 291         }
 292
 293         while ((dent = readdir(dir))) {
 294                 if (dent->d_type != DT_DIR ||
 295                     strcmp(dent->d_name, ".") == 0 ||
 296                     strcmp(dent->d_name, "..") == 0 ||
 297                     strcmp(dent->d_name, "ftrace") == 0 ||
 298                     !system_in_tp_list(dent->d_name, tps))
 299                         continue;
 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         while ((dent = readdir(dir))) {
 311                 if (dent->d_type != DT_DIR ||
 312                     strcmp(dent->d_name, ".") == 0 ||
 313                     strcmp(dent->d_name, "..") == 0 ||
 314                     strcmp(dent->d_name, "ftrace") == 0 ||
 315                     !system_in_tp_list(dent->d_name, tps))
 316                         continue;
 317                 if (asprintf(&sys, "%s/%s", path, dent->d_name) < 0) {
 318                         err = -ENOMEM;
 319                         goto out;
 320                 }
 321                 ret = stat(sys, &st);
 322                 if (ret >= 0) {
 323                         ssize_t size = strlen(dent->d_name) + 1;
 324
 325                         if (write(output_fd, dent->d_name, size) != size ||
 326                             copy_event_system(sys, tps) < 0) {
 327                                 err = -EIO;
 328                                 free(sys);
 329                                 goto out;
 330                         }
 331                 }
 332                 free(sys);
 333         }
 334         err = 0;
 335 out:
 336         closedir(dir);
 337         put_tracing_file(path);
 338
 339         return err;
 340 }
 341
 342 static int record_proc_kallsyms(void)
 343 {
 344         unsigned long long size = 0;
 345         /*
 346          * Just to keep older perf.data file parsers happy, record a zero
 347          * sized kallsyms file, i.e. do the same thing that was done when
 348          * /proc/kallsyms (or something specified via --kallsyms, in a
 349          * different path) couldn't be read.
 350          */
 351         return write(output_fd, &size, 4) != 4 ? -EIO : 0;
 352 }
 353
 354 static int record_ftrace_printk(void)
 355 {
 356         unsigned int size;
 357         char *path;
 358         struct stat st;
 359         int ret, err = 0;
 360
 361         path = get_tracing_file("printk_formats");
 362         if (!path) {
 363                 pr_debug("can't get tracing/printk_formats");
 364                 return -ENOMEM;
 365         }
 366
 367         ret = stat(path, &st);
 368         if (ret < 0) {
 369                 /* not found */
 370                 size = 0;
 371                 if (write(output_fd, &size, 4) != 4)
 372                         err = -EIO;
 373                 goto out;
 374         }
 375         err = record_file(path, 4);
 376
 377 out:
 378         put_tracing_file(path);
 379         return err;
 380 }
 381
 382 static void
 383 put_tracepoints_path(struct tracepoint_path *tps)
 384 {
 385         while (tps) {
 386                 struct tracepoint_path *t = tps;
 387
 388                 tps = tps->next;
 389                 zfree(&t->name);
 390                 zfree(&t->system);
 391                 free(t);
 392         }
 393 }
 394
 395 static struct tracepoint_path *
 396 get_tracepoints_path(struct list_head *pattrs)
 397 {
 398         struct tracepoint_path path, *ppath = &path;
 399         struct perf_evsel *pos;
 400         int nr_tracepoints = 0;
 401
 402         list_for_each_entry(pos, pattrs, node) {
 403                 if (pos->attr.type != PERF_TYPE_TRACEPOINT)
 404                         continue;
 405                 ++nr_tracepoints;
 406
 407                 if (pos->name) {
 408                         ppath->next = tracepoint_name_to_path(pos->name);
 409                         if (ppath->next)
 410                                 goto next;
 411
 412                         if (strchr(pos->name, ':') == NULL)
 413                                 goto try_id;
 414
 415                         goto error;
 416                 }
 417
 418 try_id:
 419                 ppath->next = tracepoint_id_to_path(pos->attr.config);
 420                 if (!ppath->next) {
 421 error:
 422                         pr_debug("No memory to alloc tracepoints list\n");
 423                         put_tracepoints_path(&path);
 424                         return NULL;
 425                 }
 426 next:
 427                 ppath = ppath->next;
 428         }
 429
 430         return nr_tracepoints > 0 ? path.next : NULL;
 431 }
 432
 433 bool have_tracepoints(struct list_head *pattrs)
 434 {
 435         struct perf_evsel *pos;
 436
 437         list_for_each_entry(pos, pattrs, node)
 438                 if (pos->attr.type == PERF_TYPE_TRACEPOINT)
 439                         return true;
 440
 441         return false;
 442 }
 443
 444 static int tracing_data_header(void)
 445 {
 446         char buf[20];
 447         ssize_t size;
 448
 449         /* just guessing this is someone's birthday.. ;) */
 450         buf[0] = 23;
 451         buf[1] = 8;
 452         buf[2] = 68;
 453         memcpy(buf + 3, "tracing", 7);
 454
 455         if (write(output_fd, buf, 10) != 10)
 456                 return -1;
 457
 458         size = strlen(VERSION) + 1;
 459         if (write(output_fd, VERSION, size) != size)
 460                 return -1;
 461
 462         /* save endian */
 463         if (bigendian())
 464                 buf[0] = 1;
 465         else
 466                 buf[0] = 0;
 467
 468         if (write(output_fd, buf, 1) != 1)
 469                 return -1;
 470
 471         /* save size of long */
 472         buf[0] = sizeof(long);
 473         if (write(output_fd, buf, 1) != 1)
 474                 return -1;
 475
 476         /* save page_size */
 477         if (write(output_fd, &page_size, 4) != 4)
 478                 return -1;
 479
 480         return 0;
 481 }
 482
 483 struct tracing_data *tracing_data_get(struct list_head *pattrs,
 484                                       int fd, bool temp)
 485 {
 486         struct tracepoint_path *tps;
 487         struct tracing_data *tdata;
 488         int err;
 489
 490         output_fd = fd;
 491
 492         tps = get_tracepoints_path(pattrs);
 493         if (!tps)
 494                 return NULL;
 495
 496         tdata = malloc(sizeof(*tdata));
 497         if (!tdata)
 498                 return NULL;
 499
 500         tdata->temp = temp;
 501         tdata->size = 0;
 502
 503         if (temp) {
 504                 int temp_fd;
 505
 506                 snprintf(tdata->temp_file, sizeof(tdata->temp_file),
 507                          "/tmp/perf-XXXXXX");
 508                 if (!mkstemp(tdata->temp_file)) {
 509                         pr_debug("Can't make temp file");
 510                         return NULL;
 511                 }
 512
 513                 temp_fd = open(tdata->temp_file, O_RDWR);
 514                 if (temp_fd < 0) {
 515                         pr_debug("Can't read '%s'", tdata->temp_file);
 516                         return NULL;
 517                 }
 518
 519                 /*
 520                  * Set the temp file the default output, so all the
 521                  * tracing data are stored into it.
 522                  */
 523                 output_fd = temp_fd;
 524         }
 525
 526         err = tracing_data_header();
 527         if (err)
 528                 goto out;
 529         err = record_header_files();
 530         if (err)
 531                 goto out;
 532         err = record_ftrace_files(tps);
 533         if (err)
 534                 goto out;
 535         err = record_event_files(tps);
 536         if (err)
 537                 goto out;
 538         err = record_proc_kallsyms();
 539         if (err)
 540                 goto out;
 541         err = record_ftrace_printk();
 542
 543 out:
 544         /*
 545          * All tracing data are stored by now, we can restore
 546          * the default output file in case we used temp file.
 547          */
 548         if (temp) {
 549                 tdata->size = lseek(output_fd, 0, SEEK_CUR);
 550                 close(output_fd);
 551                 output_fd = fd;
 552         }
 553
 554         if (err)
 555                 zfree(&tdata);
 556
 557         put_tracepoints_path(tps);
 558         return tdata;
 559 }
 560
 561 int tracing_data_put(struct tracing_data *tdata)
 562 {
 563         int err = 0;
 564
 565         if (tdata->temp) {
 566                 err = record_file(tdata->temp_file, 0);
 567                 unlink(tdata->temp_file);
 568         }
 569
 570         free(tdata);
 571         return err;
 572 }
 573
 574 int read_tracing_data(int fd, struct list_head *pattrs)
 575 {
 576         int err;
 577         struct tracing_data *tdata;
 578
 579         /*
 580          * We work over the real file, so we can write data
 581          * directly, no temp file is needed.
 582          */
 583         tdata = tracing_data_get(pattrs, fd, false);
 584         if (!tdata)
 585                 return -ENOMEM;
 586
 587         err = tracing_data_put(tdata);
 588         return err;
 589 }