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 <lk/debugfs.h>
  42 #include "evsel.h"
  43
  44 #define VERSION "0.5"
  45
  46 static int output_fd;
  47
  48
  49 static const char *find_debugfs(void)
  50 {
  51         const char *path = perf_debugfs_mount(NULL);
  52
  53         if (!path)
  54                 pr_debug("Your kernel does not support the debugfs filesystem");
  55
  56         return path;
  57 }
  58
  59 /*
  60  * Finds the path to the debugfs/tracing
  61  * Allocates the string and stores it.
  62  */
  63 static const char *find_tracing_dir(void)
  64 {
  65         static char *tracing;
  66         static int tracing_found;
  67         const char *debugfs;
  68
  69         if (tracing_found)
  70                 return tracing;
  71
  72         debugfs = find_debugfs();
  73         if (!debugfs)
  74                 return NULL;
  75
  76         tracing = malloc(strlen(debugfs) + 9);
  77         if (!tracing)
  78                 return NULL;
  79
  80         sprintf(tracing, "%s/tracing", debugfs);
  81
  82         tracing_found = 1;
  83         return tracing;
  84 }
  85
  86 static char *get_tracing_file(const char *name)
  87 {
  88         const char *tracing;
  89         char *file;
  90
  91         tracing = find_tracing_dir();
  92         if (!tracing)
  93                 return NULL;
  94
  95         file = malloc(strlen(tracing) + strlen(name) + 2);
  96         if (!file)
  97                 return NULL;
  98
  99         sprintf(file, "%s/%s", tracing, name);
 100         return file;
 101 }
 102
 103 static void put_tracing_file(char *file)
 104 {
 105         free(file);
 106 }
 107
 108 int bigendian(void)
 109 {
 110         unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
 111         unsigned int *ptr;
 112
 113         ptr = (unsigned int *)(void *)str;
 114         return *ptr == 0x01020304;
 115 }
 116
 117 /* unfortunately, you can not stat debugfs or proc files for size */
 118 static int record_file(const char *file, ssize_t hdr_sz)
 119 {
 120         unsigned long long size = 0;
 121         char buf[BUFSIZ], *sizep;
 122         off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
 123         int r, fd;
 124         int err = -EIO;
 125
 126         fd = open(file, O_RDONLY);
 127         if (fd < 0) {
 128                 pr_debug("Can't read '%s'", file);
 129                 return -errno;
 130         }
 131
 132         /* put in zeros for file size, then fill true size later */
 133         if (hdr_sz) {
 134                 if (write(output_fd, &size, hdr_sz) != hdr_sz)
 135                         goto out;
 136         }
 137
 138         do {
 139                 r = read(fd, buf, BUFSIZ);
 140                 if (r > 0) {
 141                         size += r;
 142                         if (write(output_fd, buf, r) != r)
 143                                 goto out;
 144                 }
 145         } while (r > 0);
 146
 147         /* ugh, handle big-endian hdr_size == 4 */
 148         sizep = (char*)&size;
 149         if (bigendian())
 150                 sizep += sizeof(u64) - hdr_sz;
 151
 152         if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
 153                 pr_debug("writing file size failed\n");
 154                 goto out;
 155         }
 156
 157         err = 0;
 158 out:
 159         close(fd);
 160         return err;
 161 }
 162
 163 static int read_header_files(void)
 164 {
 165         char *path;
 166         struct stat st;
 167         int err = -EIO;
 168
 169         path = get_tracing_file("events/header_page");
 170         if (!path) {
 171                 pr_debug("can't get tracing/events/header_page");
 172                 return -ENOMEM;
 173         }
 174
 175         if (stat(path, &st) < 0) {
 176                 pr_debug("can't read '%s'", path);
 177                 goto out;
 178         }
 179
 180         if (write(output_fd, "header_page", 12) != 12) {
 181                 pr_debug("can't write header_page\n");
 182                 goto out;
 183         }
 184
 185         if (record_file(path, 8) < 0) {
 186                 pr_debug("can't record header_page file\n");
 187                 goto out;
 188         }
 189
 190         put_tracing_file(path);
 191
 192         path = get_tracing_file("events/header_event");
 193         if (!path) {
 194                 pr_debug("can't get tracing/events/header_event");
 195                 err = -ENOMEM;
 196                 goto out;
 197         }
 198
 199         if (stat(path, &st) < 0) {
 200                 pr_debug("can't read '%s'", path);
 201                 goto out;
 202         }
 203
 204         if (write(output_fd, "header_event", 13) != 13) {
 205                 pr_debug("can't write header_event\n");
 206                 goto out;
 207         }
 208
 209         if (record_file(path, 8) < 0) {
 210                 pr_debug("can't record header_event file\n");
 211                 goto out;
 212         }
 213
 214         err = 0;
 215 out:
 216         put_tracing_file(path);
 217         return err;
 218 }
 219
 220 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
 221 {
 222         while (tps) {
 223                 if (!strcmp(sys, tps->name))
 224                         return true;
 225                 tps = tps->next;
 226         }
 227
 228         return false;
 229 }
 230
 231 static int copy_event_system(const char *sys, struct tracepoint_path *tps)
 232 {
 233         struct dirent *dent;
 234         struct stat st;
 235         char *format;
 236         DIR *dir;
 237         int count = 0;
 238         int ret;
 239         int err;
 240
 241         dir = opendir(sys);
 242         if (!dir) {
 243                 pr_debug("can't read directory '%s'", sys);
 244                 return -errno;
 245         }
 246
 247         while ((dent = readdir(dir))) {
 248                 if (dent->d_type != DT_DIR ||
 249                     strcmp(dent->d_name, ".") == 0 ||
 250                     strcmp(dent->d_name, "..") == 0 ||
 251                     !name_in_tp_list(dent->d_name, tps))
 252                         continue;
 253                 format = malloc(strlen(sys) + strlen(dent->d_name) + 10);
 254                 if (!format) {
 255                         err = -ENOMEM;
 256                         goto out;
 257                 }
 258                 sprintf(format, "%s/%s/format", sys, dent->d_name);
 259                 ret = stat(format, &st);
 260                 free(format);
 261                 if (ret < 0)
 262                         continue;
 263                 count++;
 264         }
 265
 266         if (write(output_fd, &count, 4) != 4) {
 267                 err = -EIO;
 268                 pr_debug("can't write count\n");
 269                 goto out;
 270         }
 271
 272         rewinddir(dir);
 273         while ((dent = readdir(dir))) {
 274                 if (dent->d_type != DT_DIR ||
 275                     strcmp(dent->d_name, ".") == 0 ||
 276                     strcmp(dent->d_name, "..") == 0 ||
 277                     !name_in_tp_list(dent->d_name, tps))
 278                         continue;
 279                 format = malloc(strlen(sys) + strlen(dent->d_name) + 10);
 280                 if (!format) {
 281                         err = -ENOMEM;
 282                         goto out;
 283                 }
 284                 sprintf(format, "%s/%s/format", sys, dent->d_name);
 285                 ret = stat(format, &st);
 286
 287                 if (ret >= 0) {
 288                         err = record_file(format, 8);
 289                         if (err) {
 290                                 free(format);
 291                                 goto out;
 292                         }
 293                 }
 294                 free(format);
 295         }
 296         err = 0;
 297 out:
 298         closedir(dir);
 299         return err;
 300 }
 301
 302 static int read_ftrace_files(struct tracepoint_path *tps)
 303 {
 304         char *path;
 305         int ret;
 306
 307         path = get_tracing_file("events/ftrace");
 308         if (!path) {
 309                 pr_debug("can't get tracing/events/ftrace");
 310                 return -ENOMEM;
 311         }
 312
 313         ret = copy_event_system(path, tps);
 314
 315         put_tracing_file(path);
 316
 317         return ret;
 318 }
 319
 320 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
 321 {
 322         while (tps) {
 323                 if (!strcmp(sys, tps->system))
 324                         return true;
 325                 tps = tps->next;
 326         }
 327
 328         return false;
 329 }
 330
 331 static int read_event_files(struct tracepoint_path *tps)
 332 {
 333         struct dirent *dent;
 334         struct stat st;
 335         char *path;
 336         char *sys;
 337         DIR *dir;
 338         int count = 0;
 339         int ret;
 340         int err;
 341
 342         path = get_tracing_file("events");
 343         if (!path) {
 344                 pr_debug("can't get tracing/events");
 345                 return -ENOMEM;
 346         }
 347
 348         dir = opendir(path);
 349         if (!dir) {
 350                 err = -errno;
 351                 pr_debug("can't read directory '%s'", path);
 352                 goto out;
 353         }
 354
 355         while ((dent = readdir(dir))) {
 356                 if (dent->d_type != DT_DIR ||
 357                     strcmp(dent->d_name, ".") == 0 ||
 358                     strcmp(dent->d_name, "..") == 0 ||
 359                     strcmp(dent->d_name, "ftrace") == 0 ||
 360                     !system_in_tp_list(dent->d_name, tps))
 361                         continue;
 362                 count++;
 363         }
 364
 365         if (write(output_fd, &count, 4) != 4) {
 366                 err = -EIO;
 367                 pr_debug("can't write count\n");
 368                 goto out;
 369         }
 370
 371         rewinddir(dir);
 372         while ((dent = readdir(dir))) {
 373                 if (dent->d_type != DT_DIR ||
 374                     strcmp(dent->d_name, ".") == 0 ||
 375                     strcmp(dent->d_name, "..") == 0 ||
 376                     strcmp(dent->d_name, "ftrace") == 0 ||
 377                     !system_in_tp_list(dent->d_name, tps))
 378                         continue;
 379                 sys = malloc(strlen(path) + strlen(dent->d_name) + 2);
 380                 if (!sys) {
 381                         err = -ENOMEM;
 382                         goto out;
 383                 }
 384                 sprintf(sys, "%s/%s", path, dent->d_name);
 385                 ret = stat(sys, &st);
 386                 if (ret >= 0) {
 387                         ssize_t size = strlen(dent->d_name) + 1;
 388
 389                         if (write(output_fd, dent->d_name, size) != size ||
 390                             copy_event_system(sys, tps) < 0) {
 391                                 err = -EIO;
 392                                 free(sys);
 393                                 goto out;
 394                         }
 395                 }
 396                 free(sys);
 397         }
 398         err = 0;
 399 out:
 400         closedir(dir);
 401         put_tracing_file(path);
 402
 403         return err;
 404 }
 405
 406 static int read_proc_kallsyms(void)
 407 {
 408         unsigned int size;
 409         const char *path = "/proc/kallsyms";
 410         struct stat st;
 411         int ret, err = 0;
 412
 413         ret = stat(path, &st);
 414         if (ret < 0) {
 415                 /* not found */
 416                 size = 0;
 417                 if (write(output_fd, &size, 4) != 4)
 418                         err = -EIO;
 419                 return err;
 420         }
 421         return record_file(path, 4);
 422 }
 423
 424 static int read_ftrace_printk(void)
 425 {
 426         unsigned int size;
 427         char *path;
 428         struct stat st;
 429         int ret, err = 0;
 430
 431         path = get_tracing_file("printk_formats");
 432         if (!path) {
 433                 pr_debug("can't get tracing/printk_formats");
 434                 return -ENOMEM;
 435         }
 436
 437         ret = stat(path, &st);
 438         if (ret < 0) {
 439                 /* not found */
 440                 size = 0;
 441                 if (write(output_fd, &size, 4) != 4)
 442                         err = -EIO;
 443                 goto out;
 444         }
 445         err = record_file(path, 4);
 446
 447 out:
 448         put_tracing_file(path);
 449         return err;
 450 }
 451
 452 static void
 453 put_tracepoints_path(struct tracepoint_path *tps)
 454 {
 455         while (tps) {
 456                 struct tracepoint_path *t = tps;
 457
 458                 tps = tps->next;
 459                 free(t->name);
 460                 free(t->system);
 461                 free(t);
 462         }
 463 }
 464
 465 static struct tracepoint_path *
 466 get_tracepoints_path(struct list_head *pattrs)
 467 {
 468         struct tracepoint_path path, *ppath = &path;
 469         struct perf_evsel *pos;
 470         int nr_tracepoints = 0;
 471
 472         list_for_each_entry(pos, pattrs, node) {
 473                 if (pos->attr.type != PERF_TYPE_TRACEPOINT)
 474                         continue;
 475                 ++nr_tracepoints;
 476                 ppath->next = tracepoint_id_to_path(pos->attr.config);
 477                 if (!ppath->next) {
 478                         pr_debug("No memory to alloc tracepoints list\n");
 479                         put_tracepoints_path(&path);
 480                         return NULL;
 481                 }
 482                 ppath = ppath->next;
 483         }
 484
 485         return nr_tracepoints > 0 ? path.next : NULL;
 486 }
 487
 488 bool have_tracepoints(struct list_head *pattrs)
 489 {
 490         struct perf_evsel *pos;
 491
 492         list_for_each_entry(pos, pattrs, node)
 493                 if (pos->attr.type == PERF_TYPE_TRACEPOINT)
 494                         return true;
 495
 496         return false;
 497 }
 498
 499 static int tracing_data_header(void)
 500 {
 501         char buf[20];
 502         ssize_t size;
 503
 504         /* just guessing this is someone's birthday.. ;) */
 505         buf[0] = 23;
 506         buf[1] = 8;
 507         buf[2] = 68;
 508         memcpy(buf + 3, "tracing", 7);
 509
 510         if (write(output_fd, buf, 10) != 10)
 511                 return -1;
 512
 513         size = strlen(VERSION) + 1;
 514         if (write(output_fd, VERSION, size) != size)
 515                 return -1;
 516
 517         /* save endian */
 518         if (bigendian())
 519                 buf[0] = 1;
 520         else
 521                 buf[0] = 0;
 522
 523         read_trace_init(buf[0], buf[0]);
 524
 525         if (write(output_fd, buf, 1) != 1)
 526                 return -1;
 527
 528         /* save size of long */
 529         buf[0] = sizeof(long);
 530         if (write(output_fd, buf, 1) != 1)
 531                 return -1;
 532
 533         /* save page_size */
 534         if (write(output_fd, &page_size, 4) != 4)
 535                 return -1;
 536
 537         return 0;
 538 }
 539
 540 struct tracing_data *tracing_data_get(struct list_head *pattrs,
 541                                       int fd, bool temp)
 542 {
 543         struct tracepoint_path *tps;
 544         struct tracing_data *tdata;
 545         int err;
 546
 547         output_fd = fd;
 548
 549         tps = get_tracepoints_path(pattrs);
 550         if (!tps)
 551                 return NULL;
 552
 553         tdata = malloc(sizeof(*tdata));
 554         if (!tdata)
 555                 return NULL;
 556
 557         tdata->temp = temp;
 558         tdata->size = 0;
 559
 560         if (temp) {
 561                 int temp_fd;
 562
 563                 snprintf(tdata->temp_file, sizeof(tdata->temp_file),
 564                          "/tmp/perf-XXXXXX");
 565                 if (!mkstemp(tdata->temp_file)) {
 566                         pr_debug("Can't make temp file");
 567                         return NULL;
 568                 }
 569
 570                 temp_fd = open(tdata->temp_file, O_RDWR);
 571                 if (temp_fd < 0) {
 572                         pr_debug("Can't read '%s'", tdata->temp_file);
 573                         return NULL;
 574                 }
 575
 576                 /*
 577                  * Set the temp file the default output, so all the
 578                  * tracing data are stored into it.
 579                  */
 580                 output_fd = temp_fd;
 581         }
 582
 583         err = tracing_data_header();
 584         if (err)
 585                 goto out;
 586         err = read_header_files();
 587         if (err)
 588                 goto out;
 589         err = read_ftrace_files(tps);
 590         if (err)
 591                 goto out;
 592         err = read_event_files(tps);
 593         if (err)
 594                 goto out;
 595         err = read_proc_kallsyms();
 596         if (err)
 597                 goto out;
 598         err = read_ftrace_printk();
 599
 600 out:
 601         /*
 602          * All tracing data are stored by now, we can restore
 603          * the default output file in case we used temp file.
 604          */
 605         if (temp) {
 606                 tdata->size = lseek(output_fd, 0, SEEK_CUR);
 607                 close(output_fd);
 608                 output_fd = fd;
 609         }
 610
 611         if (err) {
 612                 free(tdata);
 613                 tdata = NULL;
 614         }
 615
 616         put_tracepoints_path(tps);
 617         return tdata;
 618 }
 619
 620 int tracing_data_put(struct tracing_data *tdata)
 621 {
 622         int err = 0;
 623
 624         if (tdata->temp) {
 625                 err = record_file(tdata->temp_file, 0);
 626                 unlink(tdata->temp_file);
 627         }
 628
 629         free(tdata);
 630         return err;
 631 }
 632
 633 int read_tracing_data(int fd, struct list_head *pattrs)
 634 {
 635         int err;
 636         struct tracing_data *tdata;
 637
 638         /*
 639          * We work over the real file, so we can write data
 640          * directly, no temp file is needed.
 641          */
 642         tdata = tracing_data_get(pattrs, fd, false);
 643         if (!tdata)
 644                 return -ENOMEM;
 645
 646         err = tracing_data_put(tdata);
 647         return err;
 648 }