kernel/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/debugfs.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 int size;
 345         const char *path = "/proc/kallsyms";
 346         struct stat st;
 347         int ret, err = 0;
 348
 349         ret = stat(path, &st);
 350         if (ret < 0) {
 351                 /* not found */
 352                 size = 0;
 353                 if (write(output_fd, &size, 4) != 4)
 354                         err = -EIO;
 355                 return err;
 356         }
 357         return record_file(path, 4);
 358 }
 359
 360 static int record_ftrace_printk(void)
 361 {
 362         unsigned int size;
 363         char *path;
 364         struct stat st;
 365         int ret, err = 0;
 366
 367         path = get_tracing_file("printk_formats");
 368         if (!path) {
 369                 pr_debug("can't get tracing/printk_formats");
 370                 return -ENOMEM;
 371         }
 372
 373         ret = stat(path, &st);
 374         if (ret < 0) {
 375                 /* not found */
 376                 size = 0;
 377                 if (write(output_fd, &size, 4) != 4)
 378                         err = -EIO;
 379                 goto out;
 380         }
 381         err = record_file(path, 4);
 382
 383 out:
 384         put_tracing_file(path);
 385         return err;
 386 }
 387
 388 static void
 389 put_tracepoints_path(struct tracepoint_path *tps)
 390 {
 391         while (tps) {
 392                 struct tracepoint_path *t = tps;
 393
 394                 tps = tps->next;
 395                 zfree(&t->name);
 396                 zfree(&t->system);
 397                 free(t);
 398         }
 399 }
 400
 401 static struct tracepoint_path *
 402 get_tracepoints_path(struct list_head *pattrs)
 403 {
 404         struct tracepoint_path path, *ppath = &path;
 405         struct perf_evsel *pos;
 406         int nr_tracepoints = 0;
 407
 408         list_for_each_entry(pos, pattrs, node) {
 409                 if (pos->attr.type != PERF_TYPE_TRACEPOINT)
 410                         continue;
 411                 ++nr_tracepoints;
 412
 413                 if (pos->name) {
 414                         ppath->next = tracepoint_name_to_path(pos->name);
 415                         if (ppath->next)
 416                                 goto next;
 417
 418                         if (strchr(pos->name, ':') == NULL)
 419                                 goto try_id;
 420
 421                         goto error;
 422                 }
 423
 424 try_id:
 425                 ppath->next = tracepoint_id_to_path(pos->attr.config);
 426                 if (!ppath->next) {
 427 error:
 428                         pr_debug("No memory to alloc tracepoints list\n");
 429                         put_tracepoints_path(&path);
 430                         return NULL;
 431                 }
 432 next:
 433                 ppath = ppath->next;
 434         }
 435
 436         return nr_tracepoints > 0 ? path.next : NULL;
 437 }
 438
 439 bool have_tracepoints(struct list_head *pattrs)
 440 {
 441         struct perf_evsel *pos;
 442
 443         list_for_each_entry(pos, pattrs, node)
 444                 if (pos->attr.type == PERF_TYPE_TRACEPOINT)
 445                         return true;
 446
 447         return false;
 448 }
 449
 450 static int tracing_data_header(void)
 451 {
 452         char buf[20];
 453         ssize_t size;
 454
 455         /* just guessing this is someone's birthday.. ;) */
 456         buf[0] = 23;
 457         buf[1] = 8;
 458         buf[2] = 68;
 459         memcpy(buf + 3, "tracing", 7);
 460
 461         if (write(output_fd, buf, 10) != 10)
 462                 return -1;
 463
 464         size = strlen(VERSION) + 1;
 465         if (write(output_fd, VERSION, size) != size)
 466                 return -1;
 467
 468         /* save endian */
 469         if (bigendian())
 470                 buf[0] = 1;
 471         else
 472                 buf[0] = 0;
 473
 474         if (write(output_fd, buf, 1) != 1)
 475                 return -1;
 476
 477         /* save size of long */
 478         buf[0] = sizeof(long);
 479         if (write(output_fd, buf, 1) != 1)
 480                 return -1;
 481
 482         /* save page_size */
 483         if (write(output_fd, &page_size, 4) != 4)
 484                 return -1;
 485
 486         return 0;
 487 }
 488
 489 struct tracing_data *tracing_data_get(struct list_head *pattrs,
 490                                       int fd, bool temp)
 491 {
 492         struct tracepoint_path *tps;
 493         struct tracing_data *tdata;
 494         int err;
 495
 496         output_fd = fd;
 497
 498         tps = get_tracepoints_path(pattrs);
 499         if (!tps)
 500                 return NULL;
 501
 502         tdata = malloc(sizeof(*tdata));
 503         if (!tdata)
 504                 return NULL;
 505
 506         tdata->temp = temp;
 507         tdata->size = 0;
 508
 509         if (temp) {
 510                 int temp_fd;
 511
 512                 snprintf(tdata->temp_file, sizeof(tdata->temp_file),
 513                          "/tmp/perf-XXXXXX");
 514                 if (!mkstemp(tdata->temp_file)) {
 515                         pr_debug("Can't make temp file");
 516                         return NULL;
 517                 }
 518
 519                 temp_fd = open(tdata->temp_file, O_RDWR);
 520                 if (temp_fd < 0) {
 521                         pr_debug("Can't read '%s'", tdata->temp_file);
 522                         return NULL;
 523                 }
 524
 525                 /*
 526                  * Set the temp file the default output, so all the
 527                  * tracing data are stored into it.
 528                  */
 529                 output_fd = temp_fd;
 530         }
 531
 532         err = tracing_data_header();
 533         if (err)
 534                 goto out;
 535         err = record_header_files();
 536         if (err)
 537                 goto out;
 538         err = record_ftrace_files(tps);
 539         if (err)
 540                 goto out;
 541         err = record_event_files(tps);
 542         if (err)
 543                 goto out;
 544         err = record_proc_kallsyms();
 545         if (err)
 546                 goto out;
 547         err = record_ftrace_printk();
 548
 549 out:
 550         /*
 551          * All tracing data are stored by now, we can restore
 552          * the default output file in case we used temp file.
 553          */
 554         if (temp) {
 555                 tdata->size = lseek(output_fd, 0, SEEK_CUR);
 556                 close(output_fd);
 557                 output_fd = fd;
 558         }
 559
 560         if (err)
 561                 zfree(&tdata);
 562
 563         put_tracepoints_path(tps);
 564         return tdata;
 565 }
 566
 567 int tracing_data_put(struct tracing_data *tdata)
 568 {
 569         int err = 0;
 570
 571         if (tdata->temp) {
 572                 err = record_file(tdata->temp_file, 0);
 573                 unlink(tdata->temp_file);
 574         }
 575
 576         free(tdata);
 577         return err;
 578 }
 579
 580 int read_tracing_data(int fd, struct list_head *pattrs)
 581 {
 582         int err;
 583         struct tracing_data *tdata;
 584
 585         /*
 586          * We work over the real file, so we can write data
 587          * directly, no temp file is needed.
 588          */
 589         tdata = tracing_data_get(pattrs, fd, false);
 590         if (!tdata)
 591                 return -ENOMEM;
 592
 593         err = tracing_data_put(tdata);
 594         return err;
 595 }