From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH 2/2] virtio: fix double free_irq Date: Thu, 23 Jul 2009 12:08:35 +0300 Message-ID: <20090723090835.GB10860@redhat.com> References: <20090721155925.GC3306@redhat.com> <200907231410.32287.rusty@rustcorp.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christian Borntraeger , virtualization@lists.linux-foundation.org, Anthony Liguori , kvm@vger.kernel.org, avi@redhat.com, Carsten Otte To: Rusty Russell Return-path: Received: from mx2.redhat.com ([66.187.237.31]:48739 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752030AbZGWJKQ (ORCPT ); Thu, 23 Jul 2009 05:10:16 -0400 Content-Disposition: inline In-Reply-To: <200907231410.32287.rusty@rustcorp.com.au> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Jul 23, 2009 at 02:10:31PM +0930, Rusty Russell wrote: > On Wed, 22 Jul 2009 01:29:25 am Michael S. Tsirkin wrote: > > - if (info->vector != VIRTIO_MSI_NO_VECTOR) > > + if (info->vector != VIRTIO_MSI_NO_VECTOR) { > > free_irq(vp_dev->msix_entries[info->vector].vector, vq); > > + --vp_dev->msix_used_vectors; > > + } > > > > This only works because the only current caller of vp_del_vq is vp_del_vqs, Right > so msix_used_vectors will be 0 after all the queues have been freed. Not 0, actually, we have vectors for control and possibly a shared vector for all vqs. > Make up your mind. Either find_vq allocates and del_vq frees, or it's find_vqs > and del_vqs. I suggest the former, and setting the value VIRTIO_MSI_NO_VECTOR > to indicate it's already freed. I think with some cleanups, that loop in > vp_free_vectors might go away, too. > > Rusty. IOW, msix_used_vectors counter will be for control and shared vector for all vqs, excluding per-vq vectors. Makes sense. I'll put out a patch. -- MST