tools/perf/util/trace-event-read.c

   1 /*
   2  * Copyright (C) 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 <dirent.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <stdarg.h>
  26 #include <sys/types.h>
  27 #include <sys/stat.h>
  28 #include <sys/wait.h>
  29 #include <sys/mman.h>
  30 #include <pthread.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33 #include <errno.h>
  34
  35 #include "../perf.h"
  36 #include "util.h"
  37 #include "trace-event.h"
  38 #include "debug.h"
  39
  40 static int input_fd;
  41
  42 static ssize_t trace_data_size;
  43 static bool repipe;
  44
  45 static int __do_read(int fd, void *buf, int size)
  46 {
  47         int rsize = size;
  48
  49         while (size) {
  50                 int ret = read(fd, buf, size);
  51
  52                 if (ret <= 0)
  53                         return -1;
  54
  55                 if (repipe) {
  56                         int retw = write(STDOUT_FILENO, buf, ret);
  57
  58                         if (retw <= 0 || retw != ret) {
  59                                 pr_debug("repiping input file");
  60                                 return -1;
  61                         }
  62                 }
  63
  64                 size -= ret;
  65                 buf += ret;
  66         }
  67
  68         return rsize;
  69 }
  70
  71 static int do_read(void *data, int size)
  72 {
  73         int r;
  74
  75         r = __do_read(input_fd, data, size);
  76         if (r <= 0) {
  77                 pr_debug("reading input file (size expected=%d received=%d)",
  78                          size, r);
  79                 return -1;
  80         }
  81
  82         trace_data_size += r;
  83
  84         return r;
  85 }
  86
  87 /* If it fails, the next read will report it */
  88 static void skip(int size)
  89 {
  90         char buf[BUFSIZ];
  91         int r;
  92
  93         while (size) {
  94                 r = size > BUFSIZ ? BUFSIZ : size;
  95                 do_read(buf, r);
  96                 size -= r;
  97         };
  98 }
  99
 100 static unsigned int read4(struct pevent *pevent)
 101 {
 102         unsigned int data;
 103
 104         if (do_read(&data, 4) < 0)
 105                 return 0;
 106         return __data2host4(pevent, data);
 107 }
 108
 109 static unsigned long long read8(struct pevent *pevent)
 110 {
 111         unsigned long long data;
 112
 113         if (do_read(&data, 8) < 0)
 114                 return 0;
 115         return __data2host8(pevent, data);
 116 }
 117
 118 static char *read_string(void)
 119 {
 120         char buf[BUFSIZ];
 121         char *str = NULL;
 122         int size = 0;
 123         off_t r;
 124         char c;
 125
 126         for (;;) {
 127                 r = read(input_fd, &c, 1);
 128                 if (r < 0) {
 129                         pr_debug("reading input file");
 130                         goto out;
 131                 }
 132
 133                 if (!r) {
 134                         pr_debug("no data");
 135                         goto out;
 136                 }
 137
 138                 if (repipe) {
 139                         int retw = write(STDOUT_FILENO, &c, 1);
 140
 141                         if (retw <= 0 || retw != r) {
 142                                 pr_debug("repiping input file string");
 143                                 goto out;
 144                         }
 145                 }
 146
 147                 buf[size++] = c;
 148
 149                 if (!c)
 150                         break;
 151         }
 152
 153         trace_data_size += size;
 154
 155         str = malloc(size);
 156         if (str)
 157                 memcpy(str, buf, size);
 158 out:
 159         return str;
 160 }
 161
 162 static int read_proc_kallsyms(struct pevent *pevent)
 163 {
 164         unsigned int size;
 165
 166         size = read4(pevent);
 167         if (!size)
 168                 return 0;
 169         /*
 170          * Just skip it, now that we configure libtraceevent to use the
 171          * tools/perf/ symbol resolver.
 172          *
 173          * We need to skip it so that we can continue parsing old perf.data
 174          * files, that contains this /proc/kallsyms payload.
 175          *
 176          * Newer perf.data files will have just the 4-bytes zeros "kallsyms
 177          * payload", so that older tools can continue reading it and interpret
 178          * it as "no kallsyms payload is present".
 179          */
 180         lseek(input_fd, size, SEEK_CUR);
 181         trace_data_size += size;
 182         return 0;
 183 }
 184
 185 static int read_ftrace_printk(struct pevent *pevent)
 186 {
 187         unsigned int size;
 188         char *buf;
 189
 190         /* it can have 0 size */
 191         size = read4(pevent);
 192         if (!size)
 193                 return 0;
 194
 195         buf = malloc(size);
 196         if (buf == NULL)
 197                 return -1;
 198
 199         if (do_read(buf, size) < 0) {
 200                 free(buf);
 201                 return -1;
 202         }
 203
 204         parse_ftrace_printk(pevent, buf, size);
 205
 206         free(buf);
 207         return 0;
 208 }
 209
 210 static int read_header_files(struct pevent *pevent)
 211 {
 212         unsigned long long size;
 213         char *header_page;
 214         char buf[BUFSIZ];
 215         int ret = 0;
 216
 217         if (do_read(buf, 12) < 0)
 218                 return -1;
 219
 220         if (memcmp(buf, "header_page", 12) != 0) {
 221                 pr_debug("did not read header page");
 222                 return -1;
 223         }
 224
 225         size = read8(pevent);
 226
 227         header_page = malloc(size);
 228         if (header_page == NULL)
 229                 return -1;
 230
 231         if (do_read(header_page, size) < 0) {
 232                 pr_debug("did not read header page");
 233                 free(header_page);
 234                 return -1;
 235         }
 236
 237         if (!pevent_parse_header_page(pevent, header_page, size,
 238                                       pevent_get_long_size(pevent))) {
 239                 /*
 240                  * The commit field in the page is of type long,
 241                  * use that instead, since it represents the kernel.
 242                  */
 243                 pevent_set_long_size(pevent, pevent->header_page_size_size);
 244         }
 245         free(header_page);
 246
 247         if (do_read(buf, 13) < 0)
 248                 return -1;
 249
 250         if (memcmp(buf, "header_event", 13) != 0) {
 251                 pr_debug("did not read header event");
 252                 return -1;
 253         }
 254
 255         size = read8(pevent);
 256         skip(size);
 257
 258         return ret;
 259 }
 260
 261 static int read_ftrace_file(struct pevent *pevent, unsigned long long size)
 262 {
 263         char *buf;
 264
 265         buf = malloc(size);
 266         if (buf == NULL)
 267                 return -1;
 268
 269         if (do_read(buf, size) < 0) {
 270                 free(buf);
 271                 return -1;
 272         }
 273
 274         parse_ftrace_file(pevent, buf, size);
 275         free(buf);
 276         return 0;
 277 }
 278
 279 static int read_event_file(struct pevent *pevent, char *sys,
 280                             unsigned long long size)
 281 {
 282         char *buf;
 283
 284         buf = malloc(size);
 285         if (buf == NULL)
 286                 return -1;
 287
 288         if (do_read(buf, size) < 0) {
 289                 free(buf);
 290                 return -1;
 291         }
 292
 293         parse_event_file(pevent, buf, size, sys);
 294         free(buf);
 295         return 0;
 296 }
 297
 298 static int read_ftrace_files(struct pevent *pevent)
 299 {
 300         unsigned long long size;
 301         int count;
 302         int i;
 303         int ret;
 304
 305         count = read4(pevent);
 306
 307         for (i = 0; i < count; i++) {
 308                 size = read8(pevent);
 309                 ret = read_ftrace_file(pevent, size);
 310                 if (ret)
 311                         return ret;
 312         }
 313         return 0;
 314 }
 315
 316 static int read_event_files(struct pevent *pevent)
 317 {
 318         unsigned long long size;
 319         char *sys;
 320         int systems;
 321         int count;
 322         int i,x;
 323         int ret;
 324
 325         systems = read4(pevent);
 326
 327         for (i = 0; i < systems; i++) {
 328                 sys = read_string();
 329                 if (sys == NULL)
 330                         return -1;
 331
 332                 count = read4(pevent);
 333
 334                 for (x=0; x < count; x++) {
 335                         size = read8(pevent);
 336                         ret = read_event_file(pevent, sys, size);
 337                         if (ret)
 338                                 return ret;
 339                 }
 340         }
 341         return 0;
 342 }
 343
 344 ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
 345 {
 346         char buf[BUFSIZ];
 347         char test[] = { 23, 8, 68 };
 348         char *version;
 349         int show_version = 0;
 350         int show_funcs = 0;
 351         int show_printk = 0;
 352         ssize_t size = -1;
 353         int file_bigendian;
 354         int host_bigendian;
 355         int file_long_size;
 356         int file_page_size;
 357         struct pevent *pevent = NULL;
 358         int err;
 359
 360         repipe = __repipe;
 361         input_fd = fd;
 362
 363         if (do_read(buf, 3) < 0)
 364                 return -1;
 365         if (memcmp(buf, test, 3) != 0) {
 366                 pr_debug("no trace data in the file");
 367                 return -1;
 368         }
 369
 370         if (do_read(buf, 7) < 0)
 371                 return -1;
 372         if (memcmp(buf, "tracing", 7) != 0) {
 373                 pr_debug("not a trace file (missing 'tracing' tag)");
 374                 return -1;
 375         }
 376
 377         version = read_string();
 378         if (version == NULL)
 379                 return -1;
 380         if (show_version)
 381                 printf("version = %s\n", version);
 382         free(version);
 383
 384         if (do_read(buf, 1) < 0)
 385                 return -1;
 386         file_bigendian = buf[0];
 387         host_bigendian = bigendian();
 388
 389         if (trace_event__init(tevent)) {
 390                 pr_debug("trace_event__init failed");
 391                 goto out;
 392         }
 393
 394         pevent = tevent->pevent;
 395
 396         pevent_set_flag(pevent, PEVENT_NSEC_OUTPUT);
 397         pevent_set_file_bigendian(pevent, file_bigendian);
 398         pevent_set_host_bigendian(pevent, host_bigendian);
 399
 400         if (do_read(buf, 1) < 0)
 401                 goto out;
 402         file_long_size = buf[0];
 403
 404         file_page_size = read4(pevent);
 405         if (!file_page_size)
 406                 goto out;
 407
 408         pevent_set_long_size(pevent, file_long_size);
 409         pevent_set_page_size(pevent, file_page_size);
 410
 411         err = read_header_files(pevent);
 412         if (err)
 413                 goto out;
 414         err = read_ftrace_files(pevent);
 415         if (err)
 416                 goto out;
 417         err = read_event_files(pevent);
 418         if (err)
 419                 goto out;
 420         err = read_proc_kallsyms(pevent);
 421         if (err)
 422                 goto out;
 423         err = read_ftrace_printk(pevent);
 424         if (err)
 425                 goto out;
 426
 427         size = trace_data_size;
 428         repipe = false;
 429
 430         if (show_funcs) {
 431                 pevent_print_funcs(pevent);
 432         } else if (show_printk) {
 433                 pevent_print_printk(pevent);
 434         }
 435
 436         pevent = NULL;
 437
 438 out:
 439         if (pevent)
 440                 trace_event__cleanup(tevent);
 441         return size;
 442 }