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