From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PATCH] virtio_balloon: set DRIVER_OK before using device Date: Thu, 05 Mar 2015 13:24:47 +1030 Message-ID: <877fuwjgqw.fsf@rustcorp.com.au> References: <1425474779-29412-1-git-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1425474779-29412-1-git-send-email-mst@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: "Michael S. Tsirkin" , linux-kernel@vger.kernel.org Cc: virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org "Michael S. Tsirkin" writes: > virtio spec requires that all drivers set DRIVER_OK > before using devices. While balloon isn't yet > included in the virtio 1 spec, previous spec versions > also required this. > > virtio balloon might violate this rule: probe calls > kthread_run before setting DRIVER_OK, which might run > immediately and cause balloon to inflate/deflate. > > To fix, call virtio_device_ready before running the kthread. > > Signed-off-by: Michael S. Tsirkin Replied, CC'd stable. Thanks, Rusty. > --- > 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 5a6ad6d..6a356e3 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -508,6 +508,8 @@ static int virtballoon_probe(struct virtio_device *vdev) > if (err < 0) > goto out_oom_notify; > > + virtio_device_ready(vdev); > + > vb->thread = kthread_run(balloon, vb, "vballoon"); > if (IS_ERR(vb->thread)) { > err = PTR_ERR(vb->thread); > -- > MST