Move "exit_robust_list" into mm_release()

We don't want to get rid of the futexes just at exit() time, we want to
drop them when doing an execve() too, since that gets rid of the
previous VM image too.

Doing it at mm_release() time means that we automatically always do it
when we disassociate a VM map from the task.

Reported-by: pageexec@freemail.hu
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Alex Efros <powerman@powerman.name>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
static void exit_notify(struct task_struct *tsk, int group_dead)
{
	int signal;
	void *cookie;

	/*
	 * This does two things:
	 *
  	 * A.  Make init inherit all the child processes
	 * B.  Check to see if any process groups have become orphaned
	 *	as a result of our exiting, and if they have any stopped
	 *	jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
	 */
	forget_original_parent(tsk);
	exit_task_namespaces(tsk);

	write_lock_irq(&tasklist_lock);
	if (group_dead)
		kill_orphaned_pgrp(tsk->group_leader, NULL);

	/* Let father know we died
	 *
	 * Thread signals are configurable, but you aren't going to use
	 * that to send signals to arbitary processes.
	 * That stops right now.
	 *
	 * If the parent exec id doesn't match the exec id we saved
	 * when we started then we know the parent has changed security
	 * domain.
	 *
	 * If our self_exec id doesn't match our parent_exec_id then
	 * we have changed execution domain as these two values started
	 * the same after a fork.
	 */
	if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) &&
	    (tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
	     tsk->self_exec_id != tsk->parent_exec_id) &&
	    !capable(CAP_KILL))
		tsk->exit_signal = SIGCHLD;

	signal = tracehook_notify_death(tsk, &cookie, group_dead);
	if (signal >= 0)
		signal = do_notify_parent(tsk, signal);

	tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE;

	/* mt-exec, de_thread() is waiting for us */
	if (thread_group_leader(tsk) &&
	    tsk->signal->group_exit_task &&
	    tsk->signal->notify_count < 0)
		wake_up_process(tsk->signal->group_exit_task);

	write_unlock_irq(&tasklist_lock);

	tracehook_report_death(tsk, signal, cookie, group_dead);

	/* If the process is dead, release it - nobody will wait for it */
	if (signal == DEATH_REAP)
		release_task(tsk);
}

static void exit_notify(struct task_struct *tsk, int group_dead)
{
	int signal;
	void *cookie;

	/*
	 * This does two things:
	 *
  	 * A.  Make init inherit all the child processes
	 * B.  Check to see if any process groups have become orphaned
	 *	as a result of our exiting, and if they have any stopped
	 *	jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
	 */
	forget_original_parent(tsk);
	exit_task_namespaces(tsk);

	write_lock_irq(&tasklist_lock);
	if (group_dead)
		kill_orphaned_pgrp(tsk->group_leader, NULL);

	/* Let father know we died
	 *
	 * Thread signals are configurable, but you aren't going to use
	 * that to send signals to arbitary processes.
	 * That stops right now.
	 *
	 * If the parent exec id doesn't match the exec id we saved
	 * when we started then we know the parent has changed security
	 * domain.
	 *
	 * If our self_exec id doesn't match our parent_exec_id then
	 * we have changed execution domain as these two values started
	 * the same after a fork.
	 */
	if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) &&
	    (tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
	     tsk->self_exec_id != tsk->parent_exec_id) &&
	    !capable(CAP_KILL))
		tsk->exit_signal = SIGCHLD;

	signal = tracehook_notify_death(tsk, &cookie, group_dead);
	if (signal >= 0)
		signal = do_notify_parent(tsk, signal);

	tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE;

	/* mt-exec, de_thread() is waiting for us */
	if (thread_group_leader(tsk) &&
	    tsk->signal->group_exit_task &&
	    tsk->signal->notify_count < 0)
		wake_up_process(tsk->signal->group_exit_task);

	write_unlock_irq(&tasklist_lock);

	tracehook_report_death(tsk, signal, cookie, group_dead);

	/* If the process is dead, release it - nobody will wait for it */
	if (signal == DEATH_REAP)
		release_task(tsk);
}
