Re: [PATCH 2/3] hw/virtio: Remove NULL check in virtio_free_region_cache()

[Stefano Garzarella]

On Thu, Aug 26, 2021 at 07:26:57PM +0200, Philippe Mathieu-Daudé wrote:
> virtio_free_region_cache() is called within call_rcu(),
> always with a non-NULL argument. Ensure new code keep it
> that way by replacing the NULL check by an assertion.
> Add a comment this function is called within call_rcu().
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> hw/virtio/virtio.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index a5214bca612..3a1f6c520cb 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -133,12 +133,10 @@ struct VirtQueue
>     QLIST_ENTRY(VirtQueue) node;
> };
>
> +/* Called within call_rcu().  */
> static void virtio_free_region_cache(VRingMemoryRegionCaches *caches)
> {
> -    if (!caches) {
> -        return;
> -    }
> -
> +    assert(caches != NULL);
>     address_space_cache_destroy(&caches->desc);
>     address_space_cache_destroy(&caches->avail);
>     address_space_cache_destroy(&caches->used);
> --
> 2.31.1

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>