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Cornelia Huck

2014-Dec-09 10:46 UTC

[PATCH v3 3/6] virtio: allow finalize_features to fail

On Mon, 8 Dec 2014 15:05:58 +0200
"Michael S. Tsirkin" <mst at redhat.com> wrote:
> This will make it easy for transports to validate features and return
> failure.
> 
> Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> ---
>  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:

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,

Michael S. Tsirkin

2014-Dec-09 12:07 UTC

head link

[PATCH v3 3/6] virtio: allow finalize_features to fail

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" <mst at redhat.com> wrote:
> 
> > This will make it easy for transports to validate features and return
> > failure.
> > 
> > Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> > ---
> >  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?

Can you please send your S.O.B so I can add this patch on top?

We might also need to Cc stable.

> 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,

Cornelia Huck

2014-Dec-09 12:56 UTC

head link

[PATCH v3 3/6] virtio: allow finalize_features to fail

On Tue, 9 Dec 2014 14:07:54 +0200
"Michael S. Tsirkin" <mst at redhat.com> 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" <mst at redhat.com> wrote:
> > 
> > > This will make it easy for transports to validate features and
return
> > > failure.
> > > 
> > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> > > ---
> > >  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 <cornelia.huck at de.ibm.com>
> 
> 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,
>

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