linux/tools/testing/selftests/proc/self.c
Alexey Dobriyan 61d47c4e71 proc: test /proc/self symlink
There are plans to change how /proc/self result is calculated,
for that a test is necessary.

Use direct system call because of this whole getpid caching story.

Link: http://lkml.kernel.org/r/20180627195103.GB18113@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:45 -07:00

40 lines
1.2 KiB
C

/*
* Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
// Test that /proc/self gives correct TGID.
#undef NDEBUG
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include "proc.h"
int main(void)
{
char buf1[64], buf2[64];
pid_t pid;
ssize_t rv;
pid = sys_getpid();
snprintf(buf1, sizeof(buf1), "%u", pid);
rv = readlink("/proc/self", buf2, sizeof(buf2));
assert(rv == strlen(buf1));
buf2[rv] = '\0';
assert(streq(buf1, buf2));
return 0;
}