From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756120AbYLNIM5 (ORCPT ); Sun, 14 Dec 2008 03:12:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754399AbYLNIHd (ORCPT ); Sun, 14 Dec 2008 03:07:33 -0500 Received: from mx2.redhat.com ([66.187.237.31]:59920 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753018AbYLNIHP (ORCPT ); Sun, 14 Dec 2008 03:07:15 -0500 From: Avi Kivity To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Mark McLoughlin Subject: [PATCH 15/36] KVM: make kvm_unregister_irq_ack_notifier() safe Date: Sun, 14 Dec 2008 10:06:48 +0200 Message-Id: <1229242029-13410-16-git-send-email-avi@redhat.com> In-Reply-To: <1229242029-13410-1-git-send-email-avi@redhat.com> References: <1229242029-13410-1-git-send-email-avi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mark McLoughlin 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 Signed-off-by: Avi Kivity --- virt/kvm/irq_comm.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c index 973df99..db75045 100644 --- a/virt/kvm/irq_comm.c +++ b/virt/kvm/irq_comm.c @@ -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 */ -- 1.6.0.3