void unregister_undef_hook(struct undef_hook *hook)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&undef_lock, flags);
	list_del(&hook->node);
	raw_spin_unlock_irqrestore(&undef_lock, flags);
}
void unregister_undef_hook(struct undef_hook *hook)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&undef_lock, flags);
	list_del(&hook->node);
	raw_spin_unlock_irqrestore(&undef_lock, flags);
}