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/kernel.h>
  38
  39 #include "../perf.h"
  40 #include "trace-event.h"
  41 #include "debugfs.h"
  42
  43 #define VERSION "0.5"
  44
  45 #define _STR(x) #x
  46 #define STR(x) _STR(x)
  47 #define MAX_PATH 256
  48
  49 #define TRACE_CTRL      "tracing_on"
  50 #define TRACE           "trace"
  51 #define AVAILABLE       "available_tracers"
  52 #define CURRENT         "current_tracer"
  53 #define ITER_CTRL       "trace_options"
  54 #define MAX_LATENCY     "tracing_max_latency"
  55
  56 unsigned int page_size;
  57
  58 static const char *output_file = "trace.info";
  59 static int output_fd;
  60
  61 struct event_list {
  62         struct event_list *next;
  63         const char *event;
  64 };
  65
  66 struct events {
  67         struct events *sibling;
  68         struct events *children;
  69         struct events *next;
  70         char *name;
  71 };
  72
  73
  74
  75 static void die(const char *fmt, ...)
  76 {
  77         va_list ap;
  78         int ret = errno;
  79
  80         if (errno)
  81                 perror("trace-cmd");
  82         else
  83                 ret = -1;
  84
  85         va_start(ap, fmt);
  86         fprintf(stderr, "  ");
  87         vfprintf(stderr, fmt, ap);
  88         va_end(ap);
  89
  90         fprintf(stderr, "\n");
  91         exit(ret);
  92 }
  93
  94 void *malloc_or_die(unsigned int size)
  95 {
  96         void *data;
  97
  98         data = malloc(size);
  99         if (!data)
 100                 die("malloc");
 101         return data;
 102 }
 103
 104 static const char *find_debugfs(void)
 105 {
 106         const char *path = debugfs_mount(NULL);
 107
 108         if (!path)
 109                 die("Your kernel not support debugfs filesystem");
 110
 111         return path;
 112 }
 113
 114 /*
 115  * Finds the path to the debugfs/tracing
 116  * Allocates the string and stores it.
 117  */
 118 static const char *find_tracing_dir(void)
 119 {
 120         static char *tracing;
 121         static int tracing_found;
 122         const char *debugfs;
 123
 124         if (tracing_found)
 125                 return tracing;
 126
 127         debugfs = find_debugfs();
 128
 129         tracing = malloc_or_die(strlen(debugfs) + 9);
 130
 131         sprintf(tracing, "%s/tracing", debugfs);
 132
 133         tracing_found = 1;
 134         return tracing;
 135 }
 136
 137 static char *get_tracing_file(const char *name)
 138 {
 139         const char *tracing;
 140         char *file;
 141
 142         tracing = find_tracing_dir();
 143         if (!tracing)
 144                 return NULL;
 145
 146         file = malloc_or_die(strlen(tracing) + strlen(name) + 2);
 147
 148         sprintf(file, "%s/%s", tracing, name);
 149         return file;
 150 }
 151
 152 static void put_tracing_file(char *file)
 153 {
 154         free(file);
 155 }
 156
 157 static ssize_t write_or_die(const void *buf, size_t len)
 158 {
 159         int ret;
 160
 161         ret = write(output_fd, buf, len);
 162         if (ret < 0)
 163                 die("writing to '%s'", output_file);
 164
 165         return ret;
 166 }
 167
 168 int bigendian(void)
 169 {
 170         unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
 171         unsigned int *ptr;
 172
 173         ptr = (unsigned int *)(void *)str;
 174         return *ptr == 0x01020304;
 175 }
 176
 177 static unsigned long long copy_file_fd(int fd)
 178 {
 179         unsigned long long size = 0;
 180         char buf[BUFSIZ];
 181         int r;
 182
 183         do {
 184                 r = read(fd, buf, BUFSIZ);
 185                 if (r > 0) {
 186                         size += r;
 187                         write_or_die(buf, r);
 188                 }
 189         } while (r > 0);
 190
 191         return size;
 192 }
 193
 194 static unsigned long long copy_file(const char *file)
 195 {
 196         unsigned long long size = 0;
 197         int fd;
 198
 199         fd = open(file, O_RDONLY);
 200         if (fd < 0)
 201                 die("Can't read '%s'", file);
 202         size = copy_file_fd(fd);
 203         close(fd);
 204
 205         return size;
 206 }
 207
 208 static unsigned long get_size_fd(int fd)
 209 {
 210         unsigned long long size = 0;
 211         char buf[BUFSIZ];
 212         int r;
 213
 214         do {
 215                 r = read(fd, buf, BUFSIZ);
 216                 if (r > 0)
 217                         size += r;
 218         } while (r > 0);
 219
 220         lseek(fd, 0, SEEK_SET);
 221
 222         return size;
 223 }
 224
 225 static unsigned long get_size(const char *file)
 226 {
 227         unsigned long long size = 0;
 228         int fd;
 229
 230         fd = open(file, O_RDONLY);
 231         if (fd < 0)
 232                 die("Can't read '%s'", file);
 233         size = get_size_fd(fd);
 234         close(fd);
 235
 236         return size;
 237 }
 238
 239 static void read_header_files(void)
 240 {
 241         unsigned long long size, check_size;
 242         char *path;
 243         int fd;
 244
 245         path = get_tracing_file("events/header_page");
 246         fd = open(path, O_RDONLY);
 247         if (fd < 0)
 248                 die("can't read '%s'", path);
 249
 250         /* unfortunately, you can not stat debugfs files for size */
 251         size = get_size_fd(fd);
 252
 253         write_or_die("header_page", 12);
 254         write_or_die(&size, 8);
 255         check_size = copy_file_fd(fd);
 256         close(fd);
 257
 258         if (size != check_size)
 259                 die("wrong size for '%s' size=%lld read=%lld",
 260                     path, size, check_size);
 261         put_tracing_file(path);
 262
 263         path = get_tracing_file("events/header_event");
 264         fd = open(path, O_RDONLY);
 265         if (fd < 0)
 266                 die("can't read '%s'", path);
 267
 268         size = get_size_fd(fd);
 269
 270         write_or_die("header_event", 13);
 271         write_or_die(&size, 8);
 272         check_size = copy_file_fd(fd);
 273         if (size != check_size)
 274                 die("wrong size for '%s'", path);
 275         put_tracing_file(path);
 276         close(fd);
 277 }
 278
 279 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
 280 {
 281         while (tps) {
 282                 if (!strcmp(sys, tps->name))
 283                         return true;
 284                 tps = tps->next;
 285         }
 286
 287         return false;
 288 }
 289
 290 static void copy_event_system(const char *sys, struct tracepoint_path *tps)
 291 {
 292         unsigned long long size, check_size;
 293         struct dirent *dent;
 294         struct stat st;
 295         char *format;
 296         DIR *dir;
 297         int count = 0;
 298         int ret;
 299
 300         dir = opendir(sys);
 301         if (!dir)
 302                 die("can't read directory '%s'", sys);
 303
 304         while ((dent = readdir(dir))) {
 305                 if (dent->d_type != DT_DIR ||
 306                     strcmp(dent->d_name, ".") == 0 ||
 307                     strcmp(dent->d_name, "..") == 0 ||
 308                     !name_in_tp_list(dent->d_name, tps))
 309                         continue;
 310                 format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
 311                 sprintf(format, "%s/%s/format", sys, dent->d_name);
 312                 ret = stat(format, &st);
 313                 free(format);
 314                 if (ret < 0)
 315                         continue;
 316                 count++;
 317         }
 318
 319         write_or_die(&count, 4);
 320
 321         rewinddir(dir);
 322         while ((dent = readdir(dir))) {
 323                 if (dent->d_type != DT_DIR ||
 324                     strcmp(dent->d_name, ".") == 0 ||
 325                     strcmp(dent->d_name, "..") == 0 ||
 326                     !name_in_tp_list(dent->d_name, tps))
 327                         continue;
 328                 format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
 329                 sprintf(format, "%s/%s/format", sys, dent->d_name);
 330                 ret = stat(format, &st);
 331
 332                 if (ret >= 0) {
 333                         /* unfortunately, you can not stat debugfs files for size */
 334                         size = get_size(format);
 335                         write_or_die(&size, 8);
 336                         check_size = copy_file(format);
 337                         if (size != check_size)
 338                                 die("error in size of file '%s'", format);
 339                 }
 340
 341                 free(format);
 342         }
 343         closedir(dir);
 344 }
 345
 346 static void read_ftrace_files(struct tracepoint_path *tps)
 347 {
 348         char *path;
 349
 350         path = get_tracing_file("events/ftrace");
 351
 352         copy_event_system(path, tps);
 353
 354         put_tracing_file(path);
 355 }
 356
 357 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
 358 {
 359         while (tps) {
 360                 if (!strcmp(sys, tps->system))
 361                         return true;
 362                 tps = tps->next;
 363         }
 364
 365         return false;
 366 }
 367
 368 static void read_event_files(struct tracepoint_path *tps)
 369 {
 370         struct dirent *dent;
 371         struct stat st;
 372         char *path;
 373         char *sys;
 374         DIR *dir;
 375         int count = 0;
 376         int ret;
 377
 378         path = get_tracing_file("events");
 379
 380         dir = opendir(path);
 381         if (!dir)
 382                 die("can't read directory '%s'", path);
 383
 384         while ((dent = readdir(dir))) {
 385                 if (dent->d_type != DT_DIR ||
 386                     strcmp(dent->d_name, ".") == 0 ||
 387                     strcmp(dent->d_name, "..") == 0 ||
 388                     strcmp(dent->d_name, "ftrace") == 0 ||
 389                     !system_in_tp_list(dent->d_name, tps))
 390                         continue;
 391                 count++;
 392         }
 393
 394         write_or_die(&count, 4);
 395
 396         rewinddir(dir);
 397         while ((dent = readdir(dir))) {
 398                 if (dent->d_type != DT_DIR ||
 399                     strcmp(dent->d_name, ".") == 0 ||
 400                     strcmp(dent->d_name, "..") == 0 ||
 401                     strcmp(dent->d_name, "ftrace") == 0 ||
 402                     !system_in_tp_list(dent->d_name, tps))
 403                         continue;
 404                 sys = malloc_or_die(strlen(path) + strlen(dent->d_name) + 2);
 405                 sprintf(sys, "%s/%s", path, dent->d_name);
 406                 ret = stat(sys, &st);
 407                 if (ret >= 0) {
 408                         write_or_die(dent->d_name, strlen(dent->d_name) + 1);
 409                         copy_event_system(sys, tps);
 410                 }
 411                 free(sys);
 412         }
 413
 414         closedir(dir);
 415         put_tracing_file(path);
 416 }
 417
 418 static void read_proc_kallsyms(void)
 419 {
 420         unsigned int size, check_size;
 421         const char *path = "/proc/kallsyms";
 422         struct stat st;
 423         int ret;
 424
 425         ret = stat(path, &st);
 426         if (ret < 0) {
 427                 /* not found */
 428                 size = 0;
 429                 write_or_die(&size, 4);
 430                 return;
 431         }
 432         size = get_size(path);
 433         write_or_die(&size, 4);
 434         check_size = copy_file(path);
 435         if (size != check_size)
 436                 die("error in size of file '%s'", path);
 437
 438 }
 439
 440 static void read_ftrace_printk(void)
 441 {
 442         unsigned int size, check_size;
 443         char *path;
 444         struct stat st;
 445         int ret;
 446
 447         path = get_tracing_file("printk_formats");
 448         ret = stat(path, &st);
 449         if (ret < 0) {
 450                 /* not found */
 451                 size = 0;
 452                 write_or_die(&size, 4);
 453                 goto out;
 454         }
 455         size = get_size(path);
 456         write_or_die(&size, 4);
 457         check_size = copy_file(path);
 458         if (size != check_size)
 459                 die("error in size of file '%s'", path);
 460 out:
 461         put_tracing_file(path);
 462 }
 463
 464 static struct tracepoint_path *
 465 get_tracepoints_path(struct perf_event_attr *pattrs, int nb_events)
 466 {
 467         struct tracepoint_path path, *ppath = &path;
 468         int i, nr_tracepoints = 0;
 469
 470         for (i = 0; i < nb_events; i++) {
 471                 if (pattrs[i].type != PERF_TYPE_TRACEPOINT)
 472                         continue;
 473                 ++nr_tracepoints;
 474                 ppath->next = tracepoint_id_to_path(pattrs[i].config);
 475                 if (!ppath->next)
 476                         die("%s\n", "No memory to alloc tracepoints list");
 477                 ppath = ppath->next;
 478         }
 479
 480         return nr_tracepoints > 0 ? path.next : NULL;
 481 }
 482
 483 int read_tracing_data(int fd, struct perf_event_attr *pattrs, int nb_events)
 484 {
 485         char buf[BUFSIZ];
 486         struct tracepoint_path *tps = get_tracepoints_path(pattrs, nb_events);
 487
 488         /*
 489          * What? No tracepoints? No sense writing anything here, bail out.
 490          */
 491         if (tps == NULL)
 492                 return -1;
 493
 494         output_fd = fd;
 495
 496         buf[0] = 23;
 497         buf[1] = 8;
 498         buf[2] = 68;
 499         memcpy(buf + 3, "tracing", 7);
 500
 501         write_or_die(buf, 10);
 502
 503         write_or_die(VERSION, strlen(VERSION) + 1);
 504
 505         /* save endian */
 506         if (bigendian())
 507                 buf[0] = 1;
 508         else
 509                 buf[0] = 0;
 510
 511         write_or_die(buf, 1);
 512
 513         /* save size of long */
 514         buf[0] = sizeof(long);
 515         write_or_die(buf, 1);
 516
 517         /* save page_size */
 518         page_size = sysconf(_SC_PAGESIZE);
 519         write_or_die(&page_size, 4);
 520
 521         read_header_files();
 522         read_ftrace_files(tps);
 523         read_event_files(tps);
 524         read_proc_kallsyms();
 525         read_ftrace_printk();
 526
 527         return 0;
 528 }