[PATCH] virtio-gpu: fix shift wrapping bug in virtio_gpu_fence_event_create()

Dan Carpenter dan.carpenter at oracle.com
Thu Sep 15 11:14:14 UTC 2022


The ->ring_idx_mask variable is a u64 so static checkers, Smatch in
this case, complain if the BIT() is not also a u64.

drivers/gpu/drm/virtio/virtgpu_ioctl.c:50 virtio_gpu_fence_event_create()
warn: should '(1 << ring_idx)' be a 64 bit type?

Fixes: cd7f5ca33585 ("drm/virtio: implement context init: add virtio_gpu_fence_event")
Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
---
 drivers/gpu/drm/virtio/virtgpu_ioctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 3b1701607aae..14eedb75f8a8 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -47,7 +47,7 @@ static int virtio_gpu_fence_event_create(struct drm_device *dev,
 	struct virtio_gpu_fence_event *e = NULL;
 	int ret;
 
-	if (!(vfpriv->ring_idx_mask & (1 << ring_idx)))
+	if (!(vfpriv->ring_idx_mask & (1ULL << ring_idx)))
 		return 0;
 
 	e = kzalloc(sizeof(*e), GFP_KERNEL);
-- 
2.35.1



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