On Saturday, January 4, 2020 2:41 AM, Daniel Verkamp wrote:
> Subject: [PATCH v2 1/2] virtio-balloon: initialize all vq callbacks
>
> Ensure that elements of the callbacks 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.
The above description doesn't seem true after your second patch gets applied.
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 86a559787e6f ("virtio-balloon:
> VIRTIO_BALLOON_F_FREE_PAGE_HINT")
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> Signed-off-by: Daniel Verkamp <dverkamp@xxxxxxxxxxxx>
> ---
>
> v1:
> https://lists.linuxfoundation.org/pipermail/virtualization/2019-December/04
> 4829.html
>
> Changes from v1:
> - Clarified "array" in commit message to "callbacks array"
>
> 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;
Could you remove other redundant NULL initialization well?
https://lists.linuxfoundation.org/pipermail/virtualization/2019-December/044837.html
Best,
Wei
