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 #define _GNU_SOURCE
  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 <ctype.h>
  35 #include <errno.h>
  36 #include <stdbool.h>
  37 #include <linux/list.h>
  38 #include <linux/kernel.h>
  39
  40 #include "../perf.h"
  41 #include "trace-event.h"
  42 #include "debugfs.h"
  43 #include "evsel.h"
  44
  45 #define VERSION "0.5"
  46
  47 #define _STR(x) #x
  48 #define STR(x) _STR(x)
  49 #define MAX_PATH 256
  50
  51 #define TRACE_CTRL      "tracing_on"
  52 #define TRACE           "trace"
  53 #define AVAILABLE       "available_tracers"
  54 #define CURRENT         "current_tracer"
  55 #define ITER_CTRL       "trace_options"
  56 #define MAX_LATENCY     "tracing_max_latency"
  57
  58 unsigned int page_size;
  59
  60 static const char *output_file = "trace.info";
  61 static int output_fd;
  62
  63 struct event_list {
  64         struct event_list *next;
  65         const char *event;
  66 };
  67
  68 struct events {
  69         struct events *sibling;
  70         struct events *children;
  71         struct events *next;
  72         char *name;
  73 };
  74
  75
  76
  77 static void die(const char *fmt, ...)
  78 {
  79         va_list ap;
  80         int ret = errno;
  81
  82         if (errno)
  83                 perror("trace-cmd");
  84         else
  85                 ret = -1;
  86
  87         va_start(ap, fmt);
  88         fprintf(stderr, "  ");
  89         vfprintf(stderr, fmt, ap);
  90         va_end(ap);
  91
  92         fprintf(stderr, "\n");
  93         exit(ret);
  94 }
  95
  96 void *malloc_or_die(unsigned int size)
  97 {
  98         void *data;
  99
 100         data = malloc(size);
 101         if (!data)
 102                 die("malloc");
 103         return data;
 104 }
 105
 106 static const char *find_debugfs(void)
 107 {
 108         const char *path = debugfs_mount(NULL);
 109
 110         if (!path)
 111                 die("Your kernel not support debugfs filesystem");
 112
 113         return path;
 114 }
 115
 116 /*
 117  * Finds the path to the debugfs/tracing
 118  * Allocates the string and stores it.
 119  */
 120 static const char *find_tracing_dir(void)
 121 {
 122         static char *tracing;
 123         static int tracing_found;
 124         const char *debugfs;
 125
 126         if (tracing_found)
 127                 return tracing;
 128
 129         debugfs = find_debugfs();
 130
 131         tracing = malloc_or_die(strlen(debugfs) + 9);
 132
 133         sprintf(tracing, "%s/tracing", debugfs);
 134
 135         tracing_found = 1;
 136         return tracing;
 137 }
 138
 139 static char *get_tracing_file(const char *name)
 140 {
 141         const char *tracing;
 142         char *file;
 143
 144         tracing = find_tracing_dir();
 145         if (!tracing)
 146                 return NULL;
 147
 148         file = malloc_or_die(strlen(tracing) + strlen(name) + 2);
 149
 150         sprintf(file, "%s/%s", tracing, name);
 151         return file;
 152 }
 153
 154 static void put_tracing_file(char *file)
 155 {
 156         free(file);
 157 }
 158
 159 static ssize_t calc_data_size;
 160
 161 static ssize_t write_or_die(const void *buf, size_t len)
 162 {
 163         int ret;
 164
 165         if (calc_data_size) {
 166                 calc_data_size += len;
 167                 return len;
 168         }
 169
 170         ret = write(output_fd, buf, len);
 171         if (ret < 0)
 172                 die("writing to '%s'", output_file);
 173
 174         return ret;
 175 }
 176
 177 int bigendian(void)
 178 {
 179         unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
 180         unsigned int *ptr;
 181
 182         ptr = (unsigned int *)(void *)str;
 183         return *ptr == 0x01020304;
 184 }
 185
 186 /* unfortunately, you can not stat debugfs or proc files for size */
 187 static void record_file(const char *file, size_t hdr_sz)
 188 {
 189         unsigned long long size = 0;
 190         char buf[BUFSIZ], *sizep;
 191         off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
 192         int r, fd;
 193
 194         fd = open(file, O_RDONLY);
 195         if (fd < 0)
 196                 die("Can't read '%s'", file);
 197
 198         /* put in zeros for file size, then fill true size later */
 199         write_or_die(&size, hdr_sz);
 200
 201         do {
 202                 r = read(fd, buf, BUFSIZ);
 203                 if (r > 0) {
 204                         size += r;
 205                         write_or_die(buf, r);
 206                 }
 207         } while (r > 0);
 208         close(fd);
 209
 210         /* ugh, handle big-endian hdr_size == 4 */
 211         sizep = (char*)&size;
 212         if (bigendian())
 213                 sizep += sizeof(u64) - hdr_sz;
 214
 215         if (pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0)
 216                 die("writing to %s", output_file);
 217 }
 218
 219 static void read_header_files(void)
 220 {
 221         char *path;
 222         struct stat st;
 223
 224         path = get_tracing_file("events/header_page");
 225         if (stat(path, &st) < 0)
 226                 die("can't read '%s'", path);
 227
 228         write_or_die("header_page", 12);
 229         record_file(path, 8);
 230         put_tracing_file(path);
 231
 232         path = get_tracing_file("events/header_event");
 233         if (stat(path, &st) < 0)
 234                 die("can't read '%s'", path);
 235
 236         write_or_die("header_event", 13);
 237         record_file(path, 8);
 238         put_tracing_file(path);
 239 }
 240
 241 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
 242 {
 243         while (tps) {
 244                 if (!strcmp(sys, tps->name))
 245                         return true;
 246                 tps = tps->next;
 247         }
 248
 249         return false;
 250 }
 251
 252 static void copy_event_system(const char *sys, struct tracepoint_path *tps)
 253 {
 254         struct dirent *dent;
 255         struct stat st;
 256         char *format;
 257         DIR *dir;
 258         int count = 0;
 259         int ret;
 260
 261         dir = opendir(sys);
 262         if (!dir)
 263                 die("can't read directory '%s'", sys);
 264
 265         while ((dent = readdir(dir))) {
 266                 if (dent->d_type != DT_DIR ||
 267                     strcmp(dent->d_name, ".") == 0 ||
 268                     strcmp(dent->d_name, "..") == 0 ||
 269                     !name_in_tp_list(dent->d_name, tps))
 270                         continue;
 271                 format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
 272                 sprintf(format, "%s/%s/format", sys, dent->d_name);
 273                 ret = stat(format, &st);
 274                 free(format);
 275                 if (ret < 0)
 276                         continue;
 277                 count++;
 278         }
 279
 280         write_or_die(&count, 4);
 281
 282         rewinddir(dir);
 283         while ((dent = readdir(dir))) {
 284                 if (dent->d_type != DT_DIR ||
 285                     strcmp(dent->d_name, ".") == 0 ||
 286                     strcmp(dent->d_name, "..") == 0 ||
 287                     !name_in_tp_list(dent->d_name, tps))
 288                         continue;
 289                 format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
 290                 sprintf(format, "%s/%s/format", sys, dent->d_name);
 291                 ret = stat(format, &st);
 292
 293                 if (ret >= 0)
 294                         record_file(format, 8);
 295
 296                 free(format);
 297         }
 298         closedir(dir);
 299 }
 300
 301 static void read_ftrace_files(struct tracepoint_path *tps)
 302 {
 303         char *path;
 304
 305         path = get_tracing_file("events/ftrace");
 306
 307         copy_event_system(path, tps);
 308
 309         put_tracing_file(path);
 310 }
 311
 312 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
 313 {
 314         while (tps) {
 315                 if (!strcmp(sys, tps->system))
 316                         return true;
 317                 tps = tps->next;
 318         }
 319
 320         return false;
 321 }
 322
 323 static void read_event_files(struct tracepoint_path *tps)
 324 {
 325         struct dirent *dent;
 326         struct stat st;
 327         char *path;
 328         char *sys;
 329         DIR *dir;
 330         int count = 0;
 331         int ret;
 332
 333         path = get_tracing_file("events");
 334
 335         dir = opendir(path);
 336         if (!dir)
 337                 die("can't read directory '%s'", path);
 338
 339         while ((dent = readdir(dir))) {
 340                 if (dent->d_type != DT_DIR ||
 341                     strcmp(dent->d_name, ".") == 0 ||
 342                     strcmp(dent->d_name, "..") == 0 ||
 343                     strcmp(dent->d_name, "ftrace") == 0 ||
 344                     !system_in_tp_list(dent->d_name, tps))
 345                         continue;
 346                 count++;
 347         }
 348
 349         write_or_die(&count, 4);
 350
 351         rewinddir(dir);
 352         while ((dent = readdir(dir))) {
 353                 if (dent->d_type != DT_DIR ||
 354                     strcmp(dent->d_name, ".") == 0 ||
 355                     strcmp(dent->d_name, "..") == 0 ||
 356                     strcmp(dent->d_name, "ftrace") == 0 ||
 357                     !system_in_tp_list(dent->d_name, tps))
 358                         continue;
 359                 sys = malloc_or_die(strlen(path) + strlen(dent->d_name) + 2);
 360                 sprintf(sys, "%s/%s", path, dent->d_name);
 361                 ret = stat(sys, &st);
 362                 if (ret >= 0) {
 363                         write_or_die(dent->d_name, strlen(dent->d_name) + 1);
 364                         copy_event_system(sys, tps);
 365                 }
 366                 free(sys);
 367         }
 368
 369         closedir(dir);
 370         put_tracing_file(path);
 371 }
 372
 373 static void read_proc_kallsyms(void)
 374 {
 375         unsigned int size;
 376         const char *path = "/proc/kallsyms";
 377         struct stat st;
 378         int ret;
 379
 380         ret = stat(path, &st);
 381         if (ret < 0) {
 382                 /* not found */
 383                 size = 0;
 384                 write_or_die(&size, 4);
 385                 return;
 386         }
 387         record_file(path, 4);
 388 }
 389
 390 static void read_ftrace_printk(void)
 391 {
 392         unsigned int size;
 393         char *path;
 394         struct stat st;
 395         int ret;
 396
 397         path = get_tracing_file("printk_formats");
 398         ret = stat(path, &st);
 399         if (ret < 0) {
 400                 /* not found */
 401                 size = 0;
 402                 write_or_die(&size, 4);
 403                 goto out;
 404         }
 405         record_file(path, 4);
 406
 407 out:
 408         put_tracing_file(path);
 409 }
 410
 411 static struct tracepoint_path *
 412 get_tracepoints_path(struct list_head *pattrs)
 413 {
 414         struct tracepoint_path path, *ppath = &path;
 415         struct perf_evsel *pos;
 416         int nr_tracepoints = 0;
 417
 418         list_for_each_entry(pos, pattrs, node) {
 419                 if (pos->attr.type != PERF_TYPE_TRACEPOINT)
 420                         continue;
 421                 ++nr_tracepoints;
 422                 ppath->next = tracepoint_id_to_path(pos->attr.config);
 423                 if (!ppath->next)
 424                         die("%s\n", "No memory to alloc tracepoints list");
 425                 ppath = ppath->next;
 426         }
 427
 428         return nr_tracepoints > 0 ? path.next : NULL;
 429 }
 430
 431 bool have_tracepoints(struct list_head *pattrs)
 432 {
 433         struct perf_evsel *pos;
 434
 435         list_for_each_entry(pos, pattrs, node)
 436                 if (pos->attr.type == PERF_TYPE_TRACEPOINT)
 437                         return true;
 438
 439         return false;
 440 }
 441
 442 int read_tracing_data(int fd, struct list_head *pattrs)
 443 {
 444         char buf[BUFSIZ];
 445         struct tracepoint_path *tps = get_tracepoints_path(pattrs);
 446
 447         /*
 448          * What? No tracepoints? No sense writing anything here, bail out.
 449          */
 450         if (tps == NULL)
 451                 return -1;
 452
 453         output_fd = fd;
 454
 455         buf[0] = 23;
 456         buf[1] = 8;
 457         buf[2] = 68;
 458         memcpy(buf + 3, "tracing", 7);
 459
 460         write_or_die(buf, 10);
 461
 462         write_or_die(VERSION, strlen(VERSION) + 1);
 463
 464         /* save endian */
 465         if (bigendian())
 466                 buf[0] = 1;
 467         else
 468                 buf[0] = 0;
 469
 470         write_or_die(buf, 1);
 471
 472         /* save size of long */
 473         buf[0] = sizeof(long);
 474         write_or_die(buf, 1);
 475
 476         /* save page_size */
 477         page_size = sysconf(_SC_PAGESIZE);
 478         write_or_die(&page_size, 4);
 479
 480         read_header_files();
 481         read_ftrace_files(tps);
 482         read_event_files(tps);
 483         read_proc_kallsyms();
 484         read_ftrace_printk();
 485
 486         return 0;
 487 }
 488
 489 ssize_t read_tracing_data_size(int fd, struct list_head *pattrs)
 490 {
 491         ssize_t size;
 492         int err = 0;
 493
 494         calc_data_size = 1;
 495         err = read_tracing_data(fd, pattrs);
 496         size = calc_data_size - 1;
 497         calc_data_size = 0;
 498
 499         if (err < 0)
 500                 return err;
 501
 502         return size;
 503 }