leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

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

Browse Source 
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: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexey Dobriyan 2018-04-10 16:42:23 -07:00 committed by Linus Torvalds
parent fe079a5e10
commit 5de3d401b7
3 changed files with 85 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
tools/testing/selftests/proc/.gitignore vendored
View File

@ -1,3 +1,4 @@
/proc-loadavg-001
/proc-self-map-files-001
/proc-self-map-files-002
/proc-self-syscall

1
tools/testing/selftests/proc/Makefile
View File

@ -1,6 +1,7 @@
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

83
tools/testing/selftests/proc/proc-loadavg-001.c Normal file
View File

@ -0,0 +1,83 @@
/*
* 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;
}