linux/tools/perf/util/trace-event-info.c
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   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 <api/fs/tracing_path.h>
  42#include "evsel.h"
  43#include "debug.h"
  44
  45#define VERSION "0.5"
  46
  47static int output_fd;
  48
  49
  50int bigendian(void)
  51{
  52        unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
  53        unsigned int *ptr;
  54
  55        ptr = (unsigned int *)(void *)str;
  56        return *ptr == 0x01020304;
  57}
  58
  59/* unfortunately, you can not stat debugfs or proc files for size */
  60static int record_file(const char *file, ssize_t hdr_sz)
  61{
  62        unsigned long long size = 0;
  63        char buf[BUFSIZ], *sizep;
  64        off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
  65        int r, fd;
  66        int err = -EIO;
  67
  68        fd = open(file, O_RDONLY);
  69        if (fd < 0) {
  70                pr_debug("Can't read '%s'", file);
  71                return -errno;
  72        }
  73
  74        /* put in zeros for file size, then fill true size later */
  75        if (hdr_sz) {
  76                if (write(output_fd, &size, hdr_sz) != hdr_sz)
  77                        goto out;
  78        }
  79
  80        do {
  81                r = read(fd, buf, BUFSIZ);
  82                if (r > 0) {
  83                        size += r;
  84                        if (write(output_fd, buf, r) != r)
  85                                goto out;
  86                }
  87        } while (r > 0);
  88
  89        /* ugh, handle big-endian hdr_size == 4 */
  90        sizep = (char*)&size;
  91        if (bigendian())
  92                sizep += sizeof(u64) - hdr_sz;
  93
  94        if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
  95                pr_debug("writing file size failed\n");
  96                goto out;
  97        }
  98
  99        err = 0;
 100out:
 101        close(fd);
 102        return err;
 103}
 104
 105static int record_header_files(void)
 106{
 107        char *path;
 108        struct stat st;
 109        int err = -EIO;
 110
 111        path = get_tracing_file("events/header_page");
 112        if (!path) {
 113                pr_debug("can't get tracing/events/header_page");
 114                return -ENOMEM;
 115        }
 116
 117        if (stat(path, &st) < 0) {
 118                pr_debug("can't read '%s'", path);
 119                goto out;
 120        }
 121
 122        if (write(output_fd, "header_page", 12) != 12) {
 123                pr_debug("can't write header_page\n");
 124                goto out;
 125        }
 126
 127        if (record_file(path, 8) < 0) {
 128                pr_debug("can't record header_page file\n");
 129                goto out;
 130        }
 131
 132        put_tracing_file(path);
 133
 134        path = get_tracing_file("events/header_event");
 135        if (!path) {
 136                pr_debug("can't get tracing/events/header_event");
 137                err = -ENOMEM;
 138                goto out;
 139        }
 140
 141        if (stat(path, &st) < 0) {
 142                pr_debug("can't read '%s'", path);
 143                goto out;
 144        }
 145
 146        if (write(output_fd, "header_event", 13) != 13) {
 147                pr_debug("can't write header_event\n");
 148                goto out;
 149        }
 150
 151        if (record_file(path, 8) < 0) {
 152                pr_debug("can't record header_event file\n");
 153                goto out;
 154        }
 155
 156        err = 0;
 157out:
 158        put_tracing_file(path);
 159        return err;
 160}
 161
 162static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
 163{
 164        while (tps) {
 165                if (!strcmp(sys, tps->name))
 166                        return true;
 167                tps = tps->next;
 168        }
 169
 170        return false;
 171}
 172
 173static int copy_event_system(const char *sys, struct tracepoint_path *tps)
 174{
 175        struct dirent *dent;
 176        struct stat st;
 177        char *format;
 178        DIR *dir;
 179        int count = 0;
 180        int ret;
 181        int err;
 182
 183        dir = opendir(sys);
 184        if (!dir) {
 185                pr_debug("can't read directory '%s'", sys);
 186                return -errno;
 187        }
 188
 189        while ((dent = readdir(dir))) {
 190                if (dent->d_type != DT_DIR ||
 191                    strcmp(dent->d_name, ".") == 0 ||
 192                    strcmp(dent->d_name, "..") == 0 ||
 193                    !name_in_tp_list(dent->d_name, tps))
 194                        continue;
 195                if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
 196                        err = -ENOMEM;
 197                        goto out;
 198                }
 199                ret = stat(format, &st);
 200                free(format);
 201                if (ret < 0)
 202                        continue;
 203                count++;
 204        }
 205
 206        if (write(output_fd, &count, 4) != 4) {
 207                err = -EIO;
 208                pr_debug("can't write count\n");
 209                goto out;
 210        }
 211
 212        rewinddir(dir);
 213        while ((dent = readdir(dir))) {
 214                if (dent->d_type != DT_DIR ||
 215                    strcmp(dent->d_name, ".") == 0 ||
 216                    strcmp(dent->d_name, "..") == 0 ||
 217                    !name_in_tp_list(dent->d_name, tps))
 218                        continue;
 219                if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
 220                        err = -ENOMEM;
 221                        goto out;
 222                }
 223                ret = stat(format, &st);
 224
 225                if (ret >= 0) {
 226                        err = record_file(format, 8);
 227                        if (err) {
 228                                free(format);
 229                                goto out;
 230                        }
 231                }
 232                free(format);
 233        }
 234        err = 0;
 235out:
 236        closedir(dir);
 237        return err;
 238}
 239
 240static int record_ftrace_files(struct tracepoint_path *tps)
 241{
 242        char *path;
 243        int ret;
 244
 245        path = get_tracing_file("events/ftrace");
 246        if (!path) {
 247                pr_debug("can't get tracing/events/ftrace");
 248                return -ENOMEM;
 249        }
 250
 251        ret = copy_event_system(path, tps);
 252
 253        put_tracing_file(path);
 254
 255        return ret;
 256}
 257
 258static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
 259{
 260        while (tps) {
 261                if (!strcmp(sys, tps->system))
 262                        return true;
 263                tps = tps->next;
 264        }
 265
 266        return false;
 267}
 268
 269static int record_event_files(struct tracepoint_path *tps)
 270{
 271        struct dirent *dent;
 272        struct stat st;
 273        char *path;
 274        char *sys;
 275        DIR *dir;
 276        int count = 0;
 277        int ret;
 278        int err;
 279
 280        path = get_tracing_file("events");
 281        if (!path) {
 282                pr_debug("can't get tracing/events");
 283                return -ENOMEM;
 284        }
 285
 286        dir = opendir(path);
 287        if (!dir) {
 288                err = -errno;
 289                pr_debug("can't read directory '%s'", path);
 290                goto out;
 291        }
 292
 293        while ((dent = readdir(dir))) {
 294                if (dent->d_type != DT_DIR ||
 295                    strcmp(dent->d_name, ".") == 0 ||
 296                    strcmp(dent->d_name, "..") == 0 ||
 297                    strcmp(dent->d_name, "ftrace") == 0 ||
 298                    !system_in_tp_list(dent->d_name, tps))
 299                        continue;
 300                count++;
 301        }
 302
 303        if (write(output_fd, &count, 4) != 4) {
 304                err = -EIO;
 305                pr_debug("can't write count\n");
 306                goto out;
 307        }
 308
 309        rewinddir(dir);
 310        while ((dent = readdir(dir))) {
 311                if (dent->d_type != DT_DIR ||
 312                    strcmp(dent->d_name, ".") == 0 ||
 313                    strcmp(dent->d_name, "..") == 0 ||
 314                    strcmp(dent->d_name, "ftrace") == 0 ||
 315                    !system_in_tp_list(dent->d_name, tps))
 316                        continue;
 317                if (asprintf(&sys, "%s/%s", path, dent->d_name) < 0) {
 318                        err = -ENOMEM;
 319                        goto out;
 320                }
 321                ret = stat(sys, &st);
 322                if (ret >= 0) {
 323                        ssize_t size = strlen(dent->d_name) + 1;
 324
 325                        if (write(output_fd, dent->d_name, size) != size ||
 326                            copy_event_system(sys, tps) < 0) {
 327                                err = -EIO;
 328                                free(sys);
 329                                goto out;
 330                        }
 331                }
 332                free(sys);
 333        }
 334        err = 0;
 335out:
 336        closedir(dir);
 337        put_tracing_file(path);
 338
 339        return err;
 340}
 341
 342static int record_proc_kallsyms(void)
 343{
 344        unsigned long long size = 0;
 345        /*
 346         * Just to keep older perf.data file parsers happy, record a zero
 347         * sized kallsyms file, i.e. do the same thing that was done when
 348         * /proc/kallsyms (or something specified via --kallsyms, in a
 349         * different path) couldn't be read.
 350         */
 351        return write(output_fd, &size, 4) != 4 ? -EIO : 0;
 352}
 353
 354static int record_ftrace_printk(void)
 355{
 356        unsigned int size;
 357        char *path;
 358        struct stat st;
 359        int ret, err = 0;
 360
 361        path = get_tracing_file("printk_formats");
 362        if (!path) {
 363                pr_debug("can't get tracing/printk_formats");
 364                return -ENOMEM;
 365        }
 366
 367        ret = stat(path, &st);
 368        if (ret < 0) {
 369                /* not found */
 370                size = 0;
 371                if (write(output_fd, &size, 4) != 4)
 372                        err = -EIO;
 373                goto out;
 374        }
 375        err = record_file(path, 4);
 376
 377out:
 378        put_tracing_file(path);
 379        return err;
 380}
 381
 382static void
 383put_tracepoints_path(struct tracepoint_path *tps)
 384{
 385        while (tps) {
 386                struct tracepoint_path *t = tps;
 387
 388                tps = tps->next;
 389                zfree(&t->name);
 390                zfree(&t->system);
 391                free(t);
 392        }
 393}
 394
 395static struct tracepoint_path *
 396get_tracepoints_path(struct list_head *pattrs)
 397{
 398        struct tracepoint_path path, *ppath = &path;
 399        struct perf_evsel *pos;
 400        int nr_tracepoints = 0;
 401
 402        list_for_each_entry(pos, pattrs, node) {
 403                if (pos->attr.type != PERF_TYPE_TRACEPOINT)
 404                        continue;
 405                ++nr_tracepoints;
 406
 407                if (pos->name) {
 408                        ppath->next = tracepoint_name_to_path(pos->name);
 409                        if (ppath->next)
 410                                goto next;
 411
 412                        if (strchr(pos->name, ':') == NULL)
 413                                goto try_id;
 414
 415                        goto error;
 416                }
 417
 418try_id:
 419                ppath->next = tracepoint_id_to_path(pos->attr.config);
 420                if (!ppath->next) {
 421error:
 422                        pr_debug("No memory to alloc tracepoints list\n");
 423                        put_tracepoints_path(&path);
 424                        return NULL;
 425                }
 426next:
 427                ppath = ppath->next;
 428        }
 429
 430        return nr_tracepoints > 0 ? path.next : NULL;
 431}
 432
 433bool have_tracepoints(struct list_head *pattrs)
 434{
 435        struct perf_evsel *pos;
 436
 437        list_for_each_entry(pos, pattrs, node)
 438                if (pos->attr.type == PERF_TYPE_TRACEPOINT)
 439                        return true;
 440
 441        return false;
 442}
 443
 444static int tracing_data_header(void)
 445{
 446        char buf[20];
 447        ssize_t size;
 448
 449        /* just guessing this is someone's birthday.. ;) */
 450        buf[0] = 23;
 451        buf[1] = 8;
 452        buf[2] = 68;
 453        memcpy(buf + 3, "tracing", 7);
 454
 455        if (write(output_fd, buf, 10) != 10)
 456                return -1;
 457
 458        size = strlen(VERSION) + 1;
 459        if (write(output_fd, VERSION, size) != size)
 460                return -1;
 461
 462        /* save endian */
 463        if (bigendian())
 464                buf[0] = 1;
 465        else
 466                buf[0] = 0;
 467
 468        if (write(output_fd, buf, 1) != 1)
 469                return -1;
 470
 471        /* save size of long */
 472        buf[0] = sizeof(long);
 473        if (write(output_fd, buf, 1) != 1)
 474                return -1;
 475
 476        /* save page_size */
 477        if (write(output_fd, &page_size, 4) != 4)
 478                return -1;
 479
 480        return 0;
 481}
 482
 483struct tracing_data *tracing_data_get(struct list_head *pattrs,
 484                                      int fd, bool temp)
 485{
 486        struct tracepoint_path *tps;
 487        struct tracing_data *tdata;
 488        int err;
 489
 490        output_fd = fd;
 491
 492        tps = get_tracepoints_path(pattrs);
 493        if (!tps)
 494                return NULL;
 495
 496        tdata = malloc(sizeof(*tdata));
 497        if (!tdata)
 498                return NULL;
 499
 500        tdata->temp = temp;
 501        tdata->size = 0;
 502
 503        if (temp) {
 504                int temp_fd;
 505
 506                snprintf(tdata->temp_file, sizeof(tdata->temp_file),
 507                         "/tmp/perf-XXXXXX");
 508                if (!mkstemp(tdata->temp_file)) {
 509                        pr_debug("Can't make temp file");
 510                        return NULL;
 511                }
 512
 513                temp_fd = open(tdata->temp_file, O_RDWR);
 514                if (temp_fd < 0) {
 515                        pr_debug("Can't read '%s'", tdata->temp_file);
 516                        return NULL;
 517                }
 518
 519                /*
 520                 * Set the temp file the default output, so all the
 521                 * tracing data are stored into it.
 522                 */
 523                output_fd = temp_fd;
 524        }
 525
 526        err = tracing_data_header();
 527        if (err)
 528                goto out;
 529        err = record_header_files();
 530        if (err)
 531                goto out;
 532        err = record_ftrace_files(tps);
 533        if (err)
 534                goto out;
 535        err = record_event_files(tps);
 536        if (err)
 537                goto out;
 538        err = record_proc_kallsyms();
 539        if (err)
 540                goto out;
 541        err = record_ftrace_printk();
 542
 543out:
 544        /*
 545         * All tracing data are stored by now, we can restore
 546         * the default output file in case we used temp file.
 547         */
 548        if (temp) {
 549                tdata->size = lseek(output_fd, 0, SEEK_CUR);
 550                close(output_fd);
 551                output_fd = fd;
 552        }
 553
 554        if (err)
 555                zfree(&tdata);
 556
 557        put_tracepoints_path(tps);
 558        return tdata;
 559}
 560
 561int tracing_data_put(struct tracing_data *tdata)
 562{
 563        int err = 0;
 564
 565        if (tdata->temp) {
 566                err = record_file(tdata->temp_file, 0);
 567                unlink(tdata->temp_file);
 568        }
 569
 570        free(tdata);
 571        return err;
 572}
 573
 574int read_tracing_data(int fd, struct list_head *pattrs)
 575{
 576        int err;
 577        struct tracing_data *tdata;
 578
 579        /*
 580         * We work over the real file, so we can write data
 581         * directly, no temp file is needed.
 582         */
 583        tdata = tracing_data_get(pattrs, fd, false);
 584        if (!tdata)
 585                return -ENOMEM;
 586
 587        err = tracing_data_put(tdata);
 588        return err;
 589}
 590