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 + 1);
 196         if (buf == NULL)
 197                 return -1;
 198
 199         if (do_read(buf, size) < 0) {
 200                 free(buf);
 201                 return -1;
 202         }
 203
 204         buf[size] = '\0';
 205
 206         parse_ftrace_printk(pevent, buf, size);
 207
 208         free(buf);
 209         return 0;
 210 }
 211
 212 static int read_header_files(struct pevent *pevent)
 213 {
 214         unsigned long long size;
 215         char *header_page;
 216         char buf[BUFSIZ];
 217         int ret = 0;
 218
 219         if (do_read(buf, 12) < 0)
 220                 return -1;
 221
 222         if (memcmp(buf, "header_page", 12) != 0) {
 223                 pr_debug("did not read header page");
 224                 return -1;
 225         }
 226
 227         size = read8(pevent);
 228
 229         header_page = malloc(size);
 230         if (header_page == NULL)
 231                 return -1;
 232
 233         if (do_read(header_page, size) < 0) {
 234                 pr_debug("did not read header page");
 235                 free(header_page);
 236                 return -1;
 237         }
 238
 239         if (!pevent_parse_header_page(pevent, header_page, size,
 240                                       pevent_get_long_size(pevent))) {
 241                 /*
 242                  * The commit field in the page is of type long,
 243                  * use that instead, since it represents the kernel.
 244                  */
 245                 pevent_set_long_size(pevent, pevent->header_page_size_size);
 246         }
 247         free(header_page);
 248
 249         if (do_read(buf, 13) < 0)
 250                 return -1;
 251
 252         if (memcmp(buf, "header_event", 13) != 0) {
 253                 pr_debug("did not read header event");
 254                 return -1;
 255         }
 256
 257         size = read8(pevent);
 258         skip(size);
 259
 260         return ret;
 261 }
 262
 263 static int read_ftrace_file(struct pevent *pevent, unsigned long long size)
 264 {
 265         int ret;
 266         char *buf;
 267
 268         buf = malloc(size);
 269         if (buf == NULL) {
 270                 pr_debug("memory allocation failure\n");
 271                 return -1;
 272         }
 273
 274         ret = do_read(buf, size);
 275         if (ret < 0) {
 276                 pr_debug("error reading ftrace file.\n");
 277                 goto out;
 278         }
 279
 280         ret = parse_ftrace_file(pevent, buf, size);
 281         if (ret < 0)
 282                 pr_debug("error parsing ftrace file.\n");
 283 out:
 284         free(buf);
 285         return ret;
 286 }
 287
 288 static int read_event_file(struct pevent *pevent, char *sys,
 289                             unsigned long long size)
 290 {
 291         int ret;
 292         char *buf;
 293
 294         buf = malloc(size);
 295         if (buf == NULL) {
 296                 pr_debug("memory allocation failure\n");
 297                 return -1;
 298         }
 299
 300         ret = do_read(buf, size);
 301         if (ret < 0) {
 302                 free(buf);
 303                 goto out;
 304         }
 305
 306         ret = parse_event_file(pevent, buf, size, sys);
 307         if (ret < 0)
 308                 pr_debug("error parsing event file.\n");
 309 out:
 310         free(buf);
 311         return ret;
 312 }
 313
 314 static int read_ftrace_files(struct pevent *pevent)
 315 {
 316         unsigned long long size;
 317         int count;
 318         int i;
 319         int ret;
 320
 321         count = read4(pevent);
 322
 323         for (i = 0; i < count; i++) {
 324                 size = read8(pevent);
 325                 ret = read_ftrace_file(pevent, size);
 326                 if (ret)
 327                         return ret;
 328         }
 329         return 0;
 330 }
 331
 332 static int read_event_files(struct pevent *pevent)
 333 {
 334         unsigned long long size;
 335         char *sys;
 336         int systems;
 337         int count;
 338         int i,x;
 339         int ret;
 340
 341         systems = read4(pevent);
 342
 343         for (i = 0; i < systems; i++) {
 344                 sys = read_string();
 345                 if (sys == NULL)
 346                         return -1;
 347
 348                 count = read4(pevent);
 349
 350                 for (x=0; x < count; x++) {
 351                         size = read8(pevent);
 352                         ret = read_event_file(pevent, sys, size);
 353                         if (ret)
 354                                 return ret;
 355                 }
 356         }
 357         return 0;
 358 }
 359
 360 static int read_saved_cmdline(struct pevent *pevent)
 361 {
 362         unsigned long long size;
 363         char *buf;
 364         int ret;
 365
 366         /* it can have 0 size */
 367         size = read8(pevent);
 368         if (!size)
 369                 return 0;
 370
 371         buf = malloc(size + 1);
 372         if (buf == NULL) {
 373                 pr_debug("memory allocation failure\n");
 374                 return -1;
 375         }
 376
 377         ret = do_read(buf, size);
 378         if (ret < 0) {
 379                 pr_debug("error reading saved cmdlines\n");
 380                 goto out;
 381         }
 382
 383         parse_saved_cmdline(pevent, buf, size);
 384         ret = 0;
 385 out:
 386         free(buf);
 387         return ret;
 388 }
 389
 390 ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
 391 {
 392         char buf[BUFSIZ];
 393         char test[] = { 23, 8, 68 };
 394         char *version;
 395         int show_version = 0;
 396         int show_funcs = 0;
 397         int show_printk = 0;
 398         ssize_t size = -1;
 399         int file_bigendian;
 400         int host_bigendian;
 401         int file_long_size;
 402         int file_page_size;
 403         struct pevent *pevent = NULL;
 404         int err;
 405
 406         repipe = __repipe;
 407         input_fd = fd;
 408
 409         if (do_read(buf, 3) < 0)
 410                 return -1;
 411         if (memcmp(buf, test, 3) != 0) {
 412                 pr_debug("no trace data in the file");
 413                 return -1;
 414         }
 415
 416         if (do_read(buf, 7) < 0)
 417                 return -1;
 418         if (memcmp(buf, "tracing", 7) != 0) {
 419                 pr_debug("not a trace file (missing 'tracing' tag)");
 420                 return -1;
 421         }
 422
 423         version = read_string();
 424         if (version == NULL)
 425                 return -1;
 426         if (show_version)
 427                 printf("version = %s\n", version);
 428
 429         if (do_read(buf, 1) < 0) {
 430                 free(version);
 431                 return -1;
 432         }
 433         file_bigendian = buf[0];
 434         host_bigendian = bigendian();
 435
 436         if (trace_event__init(tevent)) {
 437                 pr_debug("trace_event__init failed");
 438                 goto out;
 439         }
 440
 441         pevent = tevent->pevent;
 442
 443         pevent_set_flag(pevent, PEVENT_NSEC_OUTPUT);
 444         pevent_set_file_bigendian(pevent, file_bigendian);
 445         pevent_set_host_bigendian(pevent, host_bigendian);
 446
 447         if (do_read(buf, 1) < 0)
 448                 goto out;
 449         file_long_size = buf[0];
 450
 451         file_page_size = read4(pevent);
 452         if (!file_page_size)
 453                 goto out;
 454
 455         pevent_set_long_size(pevent, file_long_size);
 456         pevent_set_page_size(pevent, file_page_size);
 457
 458         err = read_header_files(pevent);
 459         if (err)
 460                 goto out;
 461         err = read_ftrace_files(pevent);
 462         if (err)
 463                 goto out;
 464         err = read_event_files(pevent);
 465         if (err)
 466                 goto out;
 467         err = read_proc_kallsyms(pevent);
 468         if (err)
 469                 goto out;
 470         err = read_ftrace_printk(pevent);
 471         if (err)
 472                 goto out;
 473         if (atof(version) >= 0.6) {
 474                 err = read_saved_cmdline(pevent);
 475                 if (err)
 476                         goto out;
 477         }
 478
 479         size = trace_data_size;
 480         repipe = false;
 481
 482         if (show_funcs) {
 483                 pevent_print_funcs(pevent);
 484         } else if (show_printk) {
 485                 pevent_print_printk(pevent);
 486         }
 487
 488         pevent = NULL;
 489
 490 out:
 491         if (pevent)
 492                 trace_event__cleanup(tevent);
 493         free(version);
 494         return size;
 495 }