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