Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5de3d401 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Linus Torvalds
Browse files

proc: add selftest for last field of /proc/loadavg 

Test fork counter formerly known as ->last_pid, the only part of
/proc/loadavg which can be tested.

Testing in init pid namespace is not reliable because of background
activity.

Link: http://lkml.kernel.org/r/20180311152241.GA26247@avx2


Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fe079a5e

tools/testing/selftests/proc/.gitignore

+1 −0
Original line number Diff line number Diff line 
/proc-loadavg-001

/proc-self-map-files-001

/proc-self-map-files-002

/proc-self-syscall

tools/testing/selftests/proc/Makefile

+1 −0
Original line number Diff line number Diff line 
CFLAGS += -Wall -O2



TEST_GEN_PROGS :=

TEST_GEN_PROGS += proc-loadavg-001

TEST_GEN_PROGS += proc-self-map-files-001

TEST_GEN_PROGS += proc-self-map-files-002

TEST_GEN_PROGS += proc-self-syscall

tools/testing/selftests/proc/proc-loadavg-001.c

0 → 100644
+83 −0
Original line number Diff line number Diff line 
/*

 * 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/loadavg correctly reports last pid in pid namespace. */

#define _GNU_SOURCE

#include <errno.h>

#include <sched.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <unistd.h>

#include <sys/wait.h>



int main(void)

{

	pid_t pid;

	int wstatus;



	if (unshare(CLONE_NEWPID) == -1) {

		if (errno == ENOSYS || errno == EPERM)

			return 2;

		return 1;

	}



	pid = fork();

	if (pid == -1)

		return 1;

	if (pid == 0) {

		char buf[128], *p;

		int fd;

		ssize_t rv;



		fd = open("/proc/loadavg" , O_RDONLY);

		if (fd == -1)

			return 1;

		rv = read(fd, buf, sizeof(buf));

		if (rv < 3)

			return 1;

		p = buf + rv;



		/* pid 1 */

		if (!(p[-3] == ' ' && p[-2] == '1' && p[-1] == '\n'))

			return 1;



		pid = fork();

		if (pid == -1)

			return 1;

		if (pid == 0)

			return 0;

		if (waitpid(pid, NULL, 0) == -1)

			return 1;



		lseek(fd, 0, SEEK_SET);

		rv = read(fd, buf, sizeof(buf));

		if (rv < 3)

			return 1;

		p = buf + rv;



		/* pid 2 */

		if (!(p[-3] == ' ' && p[-2] == '2' && p[-1] == '\n'))

			return 1;



		return 0;

	}



	if (waitpid(pid, &wstatus, 0) == -1)

		return 1;

	if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0)

		return 0;

	return 1;

}