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 <fcntl.h>
  32#include <unistd.h>
  33#include <errno.h>
  34#include <stdbool.h>
  35#include <linux/list.h>
  36#include <linux/kernel.h>
  37
  38#include "../perf.h"
  39#include "trace-event.h"
  40#include <api/fs/tracing_path.h>
  41#include "evsel.h"
  42#include "debug.h"
  43
  44#define VERSION "0.6"
  45
  46static int output_fd;
  47
  48
  49int bigendian(void)
  50{
  51        unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
  52        unsigned int *ptr;
  53
  54        ptr = (unsigned int *)(void *)str;
  55        return *ptr == 0x01020304;
  56}
  57
  58/* unfortunately, you can not stat debugfs or proc files for size */
  59static int record_file(const char *file, ssize_t hdr_sz)
  60{
  61        unsigned long long size = 0;
  62        char buf[BUFSIZ], *sizep;
  63        off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
  64        int r, fd;
  65        int err = -EIO;
  66
  67        fd = open(file, O_RDONLY);
  68        if (fd < 0) {
  69                pr_debug("Can't read '%s'", file);
  70                return -errno;
  71        }
  72
  73        /* put in zeros for file size, then fill true size later */
  74        if (hdr_sz) {
  75                if (write(output_fd, &size, hdr_sz) != hdr_sz)
  76                        goto out;
  77        }
  78
  79        do {
  80                r = read(fd, buf, BUFSIZ);
  81                if (r > 0) {
  82                        size += r;
  83                        if (write(output_fd, buf, r) != r)
  84                                goto out;
  85                }
  86        } while (r > 0);
  87
  88        /* ugh, handle big-endian hdr_size == 4 */
  89        sizep = (char*)&size;
  90        if (bigendian())
  91                sizep += sizeof(u64) - hdr_sz;
  92
  93        if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
  94                pr_debug("writing file size failed\n");
  95                goto out;
  96        }
  97
  98        err = 0;
  99out:
 100        close(fd);
 101        return err;
 102}
 103
 104static int record_header_files(void)
 105{
 106        char *path;
 107        struct stat st;
 108        int err = -EIO;
 109
 110        path = get_tracing_file("events/header_page");
 111        if (!path) {
 112                pr_debug("can't get tracing/events/header_page");
 113                return -ENOMEM;
 114        }
 115
 116        if (stat(path, &st) < 0) {
 117                pr_debug("can't read '%s'", path);
 118                goto out;
 119        }
 120
 121        if (write(output_fd, "header_page", 12) != 12) {
 122                pr_debug("can't write header_page\n");
 123                goto out;
 124        }
 125
 126        if (record_file(path, 8) < 0) {
 127                pr_debug("can't record header_page file\n");
 128                goto out;
 129        }
 130
 131        put_tracing_file(path);
 132
 133        path = get_tracing_file("events/header_event");
 134        if (!path) {
 135                pr_debug("can't get tracing/events/header_event");
 136                err = -ENOMEM;
 137                goto out;
 138        }
 139
 140        if (stat(path, &st) < 0) {
 141                pr_debug("can't read '%s'", path);
 142                goto out;
 143        }
 144
 145        if (write(output_fd, "header_event", 13) != 13) {
 146                pr_debug("can't write header_event\n");
 147                goto out;
 148        }
 149
 150        if (record_file(path, 8) < 0) {
 151                pr_debug("can't record header_event file\n");
 152                goto out;
 153        }
 154
 155        err = 0;
 156out:
 157        put_tracing_file(path);
 158        return err;
 159}
 160
 161static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
 162{
 163        while (tps) {
 164                if (!strcmp(sys, tps->name))
 165                        return true;
 166                tps = tps->next;
 167        }
 168
 169        return false;
 170}
 171
 172#define for_each_event(dir, dent, tps)                          \
 173        while ((dent = readdir(dir)))                           \
 174                if (dent->d_type == DT_DIR &&                   \
 175                    (strcmp(dent->d_name, ".")) &&              \
 176                    (strcmp(dent->d_name, "..")))               \
 177
 178static int copy_event_system(const char *sys, struct tracepoint_path *tps)
 179{
 180        struct dirent *dent;
 181        struct stat st;
 182        char *format;
 183        DIR *dir;
 184        int count = 0;
 185        int ret;
 186        int err;
 187
 188        dir = opendir(sys);
 189        if (!dir) {
 190                pr_debug("can't read directory '%s'", sys);
 191                return -errno;
 192        }
 193
 194        for_each_event(dir, dent, tps) {
 195                if (!name_in_tp_list(dent->d_name, tps))
 196                        continue;
 197
 198                if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
 199                        err = -ENOMEM;
 200                        goto out;
 201                }
 202                ret = stat(format, &st);
 203                free(format);
 204                if (ret < 0)
 205                        continue;
 206                count++;
 207        }
 208
 209        if (write(output_fd, &count, 4) != 4) {
 210                err = -EIO;
 211                pr_debug("can't write count\n");
 212                goto out;
 213        }
 214
 215        rewinddir(dir);
 216        for_each_event(dir, dent, tps) {
 217                if (!name_in_tp_list(dent->d_name, tps))
 218                        continue;
 219
 220                if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
 221                        err = -ENOMEM;
 222                        goto out;
 223                }
 224                ret = stat(format, &st);
 225
 226                if (ret >= 0) {
 227                        err = record_file(format, 8);
 228                        if (err) {
 229                                free(format);
 230                                goto out;
 231                        }
 232                }
 233                free(format);
 234        }
 235        err = 0;
 236out:
 237        closedir(dir);
 238        return err;
 239}
 240
 241static int record_ftrace_files(struct tracepoint_path *tps)
 242{
 243        char *path;
 244        int ret;
 245
 246        path = get_tracing_file("events/ftrace");
 247        if (!path) {
 248                pr_debug("can't get tracing/events/ftrace");
 249                return -ENOMEM;
 250        }
 251
 252        ret = copy_event_system(path, tps);
 253
 254        put_tracing_file(path);
 255
 256        return ret;
 257}
 258
 259static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
 260{
 261        while (tps) {
 262                if (!strcmp(sys, tps->system))
 263                        return true;
 264                tps = tps->next;
 265        }
 266
 267        return false;
 268}
 269
 270static int record_event_files(struct tracepoint_path *tps)
 271{
 272        struct dirent *dent;
 273        struct stat st;
 274        char *path;
 275        char *sys;
 276        DIR *dir;
 277        int count = 0;
 278        int ret;
 279        int err;
 280
 281        path = get_tracing_file("events");
 282        if (!path) {
 283                pr_debug("can't get tracing/events");
 284                return -ENOMEM;
 285        }
 286
 287        dir = opendir(path);
 288        if (!dir) {
 289                err = -errno;
 290                pr_debug("can't read directory '%s'", path);
 291                goto out;
 292        }
 293
 294        for_each_event(dir, dent, tps) {
 295                if (strcmp(dent->d_name, "ftrace") == 0 ||
 296                    !system_in_tp_list(dent->d_name, tps))
 297                        continue;
 298
 299                count++;
 300        }
 301
 302        if (write(output_fd, &count, 4) != 4) {
 303                err = -EIO;
 304                pr_debug("can't write count\n");
 305                goto out;
 306        }
 307
 308        rewinddir(dir);
 309        for_each_event(dir, dent, tps) {
 310                if (strcmp(dent->d_name, "ftrace") == 0 ||
 311                    !system_in_tp_list(dent->d_name, tps))
 312                        continue;
 313
 314                if (asprintf(&sys, "%s/%s", path, dent->d_name) < 0) {
 315                        err = -ENOMEM;
 316                        goto out;
 317                }
 318                ret = stat(sys, &st);
 319                if (ret >= 0) {
 320                        ssize_t size = strlen(dent->d_name) + 1;
 321
 322                        if (write(output_fd, dent->d_name, size) != size ||
 323                            copy_event_system(sys, tps) < 0) {
 324                                err = -EIO;
 325                                free(sys);
 326                                goto out;
 327                        }
 328                }
 329                free(sys);
 330        }
 331        err = 0;
 332out:
 333        closedir(dir);
 334        put_tracing_file(path);
 335
 336        return err;
 337}
 338
 339static int record_proc_kallsyms(void)
 340{
 341        unsigned long long size = 0;
 342        /*
 343         * Just to keep older perf.data file parsers happy, record a zero
 344         * sized kallsyms file, i.e. do the same thing that was done when
 345         * /proc/kallsyms (or something specified via --kallsyms, in a
 346         * different path) couldn't be read.
 347         */
 348        return write(output_fd, &size, 4) != 4 ? -EIO : 0;
 349}
 350
 351static int record_ftrace_printk(void)
 352{
 353        unsigned int size;
 354        char *path;
 355        struct stat st;
 356        int ret, err = 0;
 357
 358        path = get_tracing_file("printk_formats");
 359        if (!path) {
 360                pr_debug("can't get tracing/printk_formats");
 361                return -ENOMEM;
 362        }
 363
 364        ret = stat(path, &st);
 365        if (ret < 0) {
 366                /* not found */
 367                size = 0;
 368                if (write(output_fd, &size, 4) != 4)
 369                        err = -EIO;
 370                goto out;
 371        }
 372        err = record_file(path, 4);
 373
 374out:
 375        put_tracing_file(path);
 376        return err;
 377}
 378
 379static int record_saved_cmdline(void)
 380{
 381        unsigned int size;
 382        char *path;
 383        struct stat st;
 384        int ret, err = 0;
 385
 386        path = get_tracing_file("saved_cmdlines");
 387        if (!path) {
 388                pr_debug("can't get tracing/saved_cmdline");
 389                return -ENOMEM;
 390        }
 391
 392        ret = stat(path, &st);
 393        if (ret < 0) {
 394                /* not found */
 395                size = 0;
 396                if (write(output_fd, &size, 8) != 8)
 397                        err = -EIO;
 398                goto out;
 399        }
 400        err = record_file(path, 8);
 401
 402out:
 403        put_tracing_file(path);
 404        return err;
 405}
 406
 407static void
 408put_tracepoints_path(struct tracepoint_path *tps)
 409{
 410        while (tps) {
 411                struct tracepoint_path *t = tps;
 412
 413                tps = tps->next;
 414                zfree(&t->name);
 415                zfree(&t->system);
 416                free(t);
 417        }
 418}
 419
 420static struct tracepoint_path *
 421get_tracepoints_path(struct list_head *pattrs)
 422{
 423        struct tracepoint_path path, *ppath = &path;
 424        struct perf_evsel *pos;
 425        int nr_tracepoints = 0;
 426
 427        list_for_each_entry(pos, pattrs, node) {
 428                if (pos->attr.type != PERF_TYPE_TRACEPOINT)
 429                        continue;
 430                ++nr_tracepoints;
 431
 432                if (pos->name) {
 433                        ppath->next = tracepoint_name_to_path(pos->name);
 434                        if (ppath->next)
 435                                goto next;
 436
 437                        if (strchr(pos->name, ':') == NULL)
 438                                goto try_id;
 439
 440                        goto error;
 441                }
 442
 443try_id:
 444                ppath->next = tracepoint_id_to_path(pos->attr.config);
 445                if (!ppath->next) {
 446error:
 447                        pr_debug("No memory to alloc tracepoints list\n");
 448                        put_tracepoints_path(&path);
 449                        return NULL;
 450                }
 451next:
 452                ppath = ppath->next;
 453        }
 454
 455        return nr_tracepoints > 0 ? path.next : NULL;
 456}
 457
 458bool have_tracepoints(struct list_head *pattrs)
 459{
 460        struct perf_evsel *pos;
 461
 462        list_for_each_entry(pos, pattrs, node)
 463                if (pos->attr.type == PERF_TYPE_TRACEPOINT)
 464                        return true;
 465
 466        return false;
 467}
 468
 469static int tracing_data_header(void)
 470{
 471        char buf[20];
 472        ssize_t size;
 473
 474        /* just guessing this is someone's birthday.. ;) */
 475        buf[0] = 23;
 476        buf[1] = 8;
 477        buf[2] = 68;
 478        memcpy(buf + 3, "tracing", 7);
 479
 480        if (write(output_fd, buf, 10) != 10)
 481                return -1;
 482
 483        size = strlen(VERSION) + 1;
 484        if (write(output_fd, VERSION, size) != size)
 485                return -1;
 486
 487        /* save endian */
 488        if (bigendian())
 489                buf[0] = 1;
 490        else
 491                buf[0] = 0;
 492
 493        if (write(output_fd, buf, 1) != 1)
 494                return -1;
 495
 496        /* save size of long */
 497        buf[0] = sizeof(long);
 498        if (write(output_fd, buf, 1) != 1)
 499                return -1;
 500
 501        /* save page_size */
 502        if (write(output_fd, &page_size, 4) != 4)
 503                return -1;
 504
 505        return 0;
 506}
 507
 508struct tracing_data *tracing_data_get(struct list_head *pattrs,
 509                                      int fd, bool temp)
 510{
 511        struct tracepoint_path *tps;
 512        struct tracing_data *tdata;
 513        int err;
 514
 515        output_fd = fd;
 516
 517        tps = get_tracepoints_path(pattrs);
 518        if (!tps)
 519                return NULL;
 520
 521        tdata = malloc(sizeof(*tdata));
 522        if (!tdata)
 523                return NULL;
 524
 525        tdata->temp = temp;
 526        tdata->size = 0;
 527
 528        if (temp) {
 529                int temp_fd;
 530
 531                snprintf(tdata->temp_file, sizeof(tdata->temp_file),
 532                         "/tmp/perf-XXXXXX");
 533                if (!mkstemp(tdata->temp_file)) {
 534                        pr_debug("Can't make temp file");
 535                        return NULL;
 536                }
 537
 538                temp_fd = open(tdata->temp_file, O_RDWR);
 539                if (temp_fd < 0) {
 540                        pr_debug("Can't read '%s'", tdata->temp_file);
 541                        return NULL;
 542                }
 543
 544                /*
 545                 * Set the temp file the default output, so all the
 546                 * tracing data are stored into it.
 547                 */
 548                output_fd = temp_fd;
 549        }
 550
 551        err = tracing_data_header();
 552        if (err)
 553                goto out;
 554        err = record_header_files();
 555        if (err)
 556                goto out;
 557        err = record_ftrace_files(tps);
 558        if (err)
 559                goto out;
 560        err = record_event_files(tps);
 561        if (err)
 562                goto out;
 563        err = record_proc_kallsyms();
 564        if (err)
 565                goto out;
 566        err = record_ftrace_printk();
 567        if (err)
 568                goto out;
 569        err = record_saved_cmdline();
 570
 571out:
 572        /*
 573         * All tracing data are stored by now, we can restore
 574         * the default output file in case we used temp file.
 575         */
 576        if (temp) {
 577                tdata->size = lseek(output_fd, 0, SEEK_CUR);
 578                close(output_fd);
 579                output_fd = fd;
 580        }
 581
 582        if (err)
 583                zfree(&tdata);
 584
 585        put_tracepoints_path(tps);
 586        return tdata;
 587}
 588
 589int tracing_data_put(struct tracing_data *tdata)
 590{
 591        int err = 0;
 592
 593        if (tdata->temp) {
 594                err = record_file(tdata->temp_file, 0);
 595                unlink(tdata->temp_file);
 596        }
 597
 598        free(tdata);
 599        return err;
 600}
 601
 602int read_tracing_data(int fd, struct list_head *pattrs)
 603{
 604        int err;
 605        struct tracing_data *tdata;
 606
 607        /*
 608         * We work over the real file, so we can write data
 609         * directly, no temp file is needed.
 610         */
 611        tdata = tracing_data_get(pattrs, fd, false);
 612        if (!tdata)
 613                return -ENOMEM;
 614
 615        err = tracing_data_put(tdata);
 616        return err;
 617}
 618