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/*
* 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;
}
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