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