static int check_unshare_flags(unsigned long unshare_flags)
{
	if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
				CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
				CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET|
				CLONE_NEWUSER|CLONE_NEWPID))
		return -EINVAL;
	/*
	 * Not implemented, but pretend it works if there is nothing to
	 * unshare. Note that unsharing CLONE_THREAD or CLONE_SIGHAND
	 * needs to unshare vm.
	 */
	if (unshare_flags & (CLONE_THREAD | CLONE_SIGHAND | CLONE_VM)) {
		/* FIXME: get_task_mm() increments ->mm_users */
		if (atomic_read(&current->mm->mm_users) > 1)
			return -EINVAL;
	}

	return 0;
}
static int check_unshare_flags(unsigned long unshare_flags)
{
	if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
				CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
				CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET|
				CLONE_NEWUSER|CLONE_NEWPID))
		return -EINVAL;
	 
	if (unshare_flags & (CLONE_THREAD | CLONE_SIGHAND | CLONE_VM)) {
		 
		if (atomic_read(&current->mm->mm_users) > 1)
			return -EINVAL;
	}

	return 0;
}