LXR linux/tools/testing/selftests/proc/fd-002-posix-eq.c

   1/*
   2 * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
   3 *
   4 * Permission to use, copy, modify, and distribute this software for any
   5 * purpose with or without fee is hereby granted, provided that the above
   6 * copyright notice and this permission notice appear in all copies.
   7 *
   8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15 */
  16// Test that open(/proc/*/fd/*) opens the same file.
  17#undef NDEBUG
  18#include <assert.h>
  19#include <stdio.h>
  20#include <sys/types.h>
  21#include <sys/stat.h>
  22#include <fcntl.h>
  23#include <unistd.h>
  24
  25int main(void)
  26{
  27        int fd0, fd1, fd2;
  28        struct stat st0, st1, st2;
  29        char buf[64];
  30        int rv;
  31
  32        fd0 = open("/", O_DIRECTORY|O_RDONLY);
  33        assert(fd0 >= 0);
  34
  35        snprintf(buf, sizeof(buf), "/proc/self/fd/%u", fd0);
  36        fd1 = open(buf, O_RDONLY);
  37        assert(fd1 >= 0);
  38
  39        snprintf(buf, sizeof(buf), "/proc/thread-self/fd/%u", fd0);
  40        fd2 = open(buf, O_RDONLY);
  41        assert(fd2 >= 0);
  42
  43        rv = fstat(fd0, &st0);
  44        assert(rv == 0);
  45        rv = fstat(fd1, &st1);
  46        assert(rv == 0);
  47        rv = fstat(fd2, &st2);
  48        assert(rv == 0);
  49
  50        assert(st0.st_dev == st1.st_dev);
  51        assert(st0.st_ino == st1.st_ino);
  52
  53        assert(st0.st_dev == st2.st_dev);
  54        assert(st0.st_ino == st2.st_ino);
  55
  56        return 0;
  57}
  58