From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Subject: Re: [PATCH 1/2] virtio-balloon: initialize all vq callbacks Date: Wed, 18 Dec 2019 10:28:23 +0100 Message-ID: <20191218102823.790d88fa.cohuck@redhat.com> References: <20191217190610.248061-1-dverkamp@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20191217190610.248061-1-dverkamp@chromium.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: Daniel Verkamp Cc: "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org On Tue, 17 Dec 2019 11:06:09 -0800 Daniel Verkamp wrote: > Ensure that elements of the array that correspond to unavailable s/array/callbacks array/ ? > features are set to NULL; previously, they would be left uninitialized. > > Since the corresponding names array elements were explicitly set to > NULL, the uninitialized callback pointers would not actually be > dereferenced; however, the uninitialized callbacks elements would still > be read in vp_find_vqs_msix() and used to calculate the number of MSI-X > vectors required. > > Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") > Signed-off-by: Daniel Verkamp > --- > drivers/virtio/virtio_balloon.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 93f995f6cf36..8e400ece9273 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -475,7 +475,9 @@ static int init_vqs(struct virtio_balloon *vb) > names[VIRTIO_BALLOON_VQ_INFLATE] = "inflate"; > callbacks[VIRTIO_BALLOON_VQ_DEFLATE] = balloon_ack; > names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate"; > + callbacks[VIRTIO_BALLOON_VQ_STATS] = NULL; > names[VIRTIO_BALLOON_VQ_STATS] = NULL; > + callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; > names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; > > if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { Alternatively, it might make sense to zero the whole array and drop the explicit NULL assignments, which would also be a bit more future proof... but this one fixes things as well, of course. Reviewed-by: Cornelia Huck