Re: [PATCH 1/2] virtio-balloon: initialize all vq callbacks

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Dec 18, 2019 at 11:18:45AM +0800, Wei Wang wrote:
> On 12/18/2019 03:06 AM, Daniel Verkamp wrote:
> > Ensure that elements of the array that correspond to unavailable
> > 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.
> 
> With your 2nd patch:
> if (names[i] && callbacks[i])
>     ++nvectors;
> 
> It seems this patch isn't necessary as names[i] is already NULL, isn't it?
> 
> Best,
> Wei

Right but passing uninitialized values isn't nice even if
the function called happens to ignore them.