KVM: make kvm_unregister_irq_ack_notifier() safe

We never pass a NULL notifier pointer here, but we may well
pass a notifier struct which hasn't previously been
registered.

Guard against this by using hlist_del_init() which will
not do anything if the node hasn't been added to the list
and, when removing the node, will ensure that a subsequent
call to hlist_del_init() will be fine too.

Fixes an oops seen when an assigned device is freed before
and IRQ is assigned to it.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Mark McLoughlin 2008-12-01 13:57:46 +00:00 committed by Avi Kivity
parent 844c7a9ff4
commit fdd897e6b5
1 changed files with 1 additions and 3 deletions

View File

@ -63,9 +63,7 @@ void kvm_register_irq_ack_notifier(struct kvm *kvm,
void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
{
if (!kian)
return;
hlist_del(&kian->link);
hlist_del_init(&kian->link);
}
/* The caller must hold kvm->lock mutex */