Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756853AbaLIM4V (ORCPT ); Tue, 9 Dec 2014 07:56:21 -0500 Received: from e06smtp12.uk.ibm.com ([195.75.94.108]:48567 "EHLO e06smtp12.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755234AbaLIM4U (ORCPT ); Tue, 9 Dec 2014 07:56:20 -0500 Date: Tue, 9 Dec 2014 13:56:12 +0100 From: Cornelia Huck To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, dahi@linux.vnet.ibm.com, rusty@rustcorp.com.au, Ohad Ben-Cohen , Christian Borntraeger , linux390@de.ibm.com, Martin Schwidefsky , Heiko Carstens , Sudeep Dutt , Siva Yerramreddy , lguest@lists.ozlabs.org, linux-s390@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH v3 3/6] virtio: allow finalize_features to fail Message-ID: <20141209135612.0827f70d.cornelia.huck@de.ibm.com> In-Reply-To: <20141209120754.GE3993@redhat.com> References: <1418042769-25539-1-git-send-email-mst@redhat.com> <1418042769-25539-4-git-send-email-mst@redhat.com> <20141209114659.5b0fdea0.cornelia.huck@de.ibm.com> <20141209120754.GE3993@redhat.com> Organization: IBM Deutschland Research & Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz =?UTF-8?B?R2VzY2jDpGZ0c2bDvGhydW5nOg==?= Dirk Wittkopp Sitz der Gesellschaft: =?UTF-8?B?QsO2Ymxpbmdlbg==?= Registergericht: Amtsgericht Stuttgart, HRB 243294 X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14120912-0009-0000-0000-0000024EFD38 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 9 Dec 2014 14:07:54 +0200 "Michael S. Tsirkin" wrote: > On Tue, Dec 09, 2014 at 11:46:59AM +0100, Cornelia Huck wrote: > > On Mon, 8 Dec 2014 15:05:58 +0200 > > "Michael S. Tsirkin" wrote: > > > > > This will make it easy for transports to validate features and return > > > failure. > > > > > > Signed-off-by: Michael S. Tsirkin > > > --- > > > include/linux/virtio_config.h | 3 ++- > > > drivers/lguest/lguest_device.c | 4 +++- > > > drivers/misc/mic/card/mic_virtio.c | 4 +++- > > > drivers/remoteproc/remoteproc_virtio.c | 4 +++- > > > drivers/s390/kvm/kvm_virtio.c | 4 +++- > > > drivers/s390/kvm/virtio_ccw.c | 6 ++++-- > > > drivers/virtio/virtio.c | 21 ++++++++++++++------- > > > drivers/virtio/virtio_mmio.c | 4 +++- > > > drivers/virtio/virtio_pci.c | 4 +++- > > > 9 files changed, 38 insertions(+), 16 deletions(-) > > > > > > > > diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c > > > index c792b5f..789275f 100644 > > > --- a/drivers/s390/kvm/virtio_ccw.c > > > +++ b/drivers/s390/kvm/virtio_ccw.c > > > @@ -752,7 +752,7 @@ out_free: > > > return rc; > > > } > > > > > > -static void virtio_ccw_finalize_features(struct virtio_device *vdev) > > > +static int virtio_ccw_finalize_features(struct virtio_device *vdev) > > > { > > > struct virtio_ccw_device *vcdev = to_vc_device(vdev); > > > struct virtio_feature_desc *features; > > > @@ -760,7 +760,7 @@ static void virtio_ccw_finalize_features(struct virtio_device *vdev) > > > > > > ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL); > > > if (!ccw) > > > - return; > > > + return 0; > > > > I think we'll want to return an error in this case as well to fail > > probing. Also for the other places where something can go wrong. > > Something like this: > > > I guess the fact this previously failed silently is a bug in original > code? Not really a bug; it simply was not possible to fail it. > > Can you please send your S.O.B so I can add this patch on top? Sure. Code below is Signed-off-by: Cornelia Huck > > We might also need to Cc stable. Not sure whether this is stable-worthy, as these are largely pathological cases (and for the one non-pathological case, device going away, we're already fine). > > > > diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c > > index 789275f..bc6e671 100644 > > --- a/drivers/s390/kvm/virtio_ccw.c > > +++ b/drivers/s390/kvm/virtio_ccw.c > > @@ -757,15 +757,17 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev) > > struct virtio_ccw_device *vcdev = to_vc_device(vdev); > > struct virtio_feature_desc *features; > > struct ccw1 *ccw; > > + int ret; > > > > ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL); > > if (!ccw) > > - return 0; > > + return -ENOMEM; > > > > features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL); > > - if (!features) > > + if (!features) { > > + ret = -ENOMEM; > > goto out_free; > > - > > + } > > /* Give virtio_ring a chance to accept features. */ > > vring_transport_features(vdev); > > > > @@ -776,7 +778,9 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev) > > ccw->flags = 0; > > ccw->count = sizeof(*features); > > ccw->cda = (__u32)(unsigned long)features; > > - ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT); > > + ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT); > > + if (ret) > > + goto out_free; > > > > if (vcdev->revision == 0) > > goto out_free; > > @@ -788,13 +792,13 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev) > > ccw->flags = 0; > > ccw->count = sizeof(*features); > > ccw->cda = (__u32)(unsigned long)features; > > - ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT); > > + ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT); > > > > out_free: > > kfree(features); > > kfree(ccw); > > > > - return 0; > > + return ret; > > } > > > > static void virtio_ccw_get_config(struct virtio_device *vdev, > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/