umount2("/dev/pts", MNT_DETACH);
umount2("/dev/", MNT_DETACH);
mount("tmpfs", "/dev", "tmpfs", MS_NOSUID, "mode=0755,size=512K");
umount2("/dev/pts", MNT_DETACH);
umount2("/dev/", MNT_DETACH);
mount("tmpfs", "/dev", "tmpfs", MS_NOSUID, "mode=0755,size=512K");