Merge branch 'stacking-fixes' (vfs stacking fixes from Jann)

Merge filesystem stacking fixes from Jann Horn.

* emailed patches from Jann Horn <jannh@google.com>:
  sched: panic on corrupted stack end
  ecryptfs: forbid opening files without mmap handler
  proc: prevent stacking filesystems on top
void sched_destroy_group(struct task_group *tg)
{
	/* wait for possible concurrent references to cfs_rqs complete */
	call_rcu(&tg->rcu, sched_free_group_rcu);
}

void sched_destroy_group(struct task_group *tg)
{
	/* wait for possible concurrent references to cfs_rqs complete */
	call_rcu(&tg->rcu, sched_free_group_rcu);
}
