On 2019/3/6 下午7:05, Arnd Bergmann wrote:
On some architectures, the MMU can be disabled, leading to access_ok()
becoming an empty macro that does not evaluate its size argument,
which in turn produces an unused-variable warning:
drivers/vhost/vhost.c:1191:9: error: unused variable 's' [-Werror,-Wunused-variable]
size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
Mark the variable as __maybe_unused to shut up that warning.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/vhost/vhost.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a2e5dc7716e2..5ace833de746 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1188,7 +1188,7 @@ static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
struct vring_used __user *used)
{
- size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
+ size_t s __maybe_unused = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
return access_ok(desc, num * sizeof *desc) &&
access_ok(avail,
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
