Re: [PATCH] vduse: Fix error around jumping over a __cleanup() variable

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

On Wed, Jun 10, 2026 at 12:16:49PM -0700, Nathan Chancellor wrote:
> When building with clang, there is an error in vduse_vq_kick() from
> attempting to jump over a variable declared with the cleanup attribute
> using goto:
> 
>   drivers/vdpa/vdpa_user/vduse_dev.c:566:3: error: cannot jump from this goto statement to its label
>     566 |                 goto unlock;
>         |                 ^
>   drivers/vdpa/vdpa_user/vduse_dev.c:568:2: note: jump bypasses initialization of variable with __attribute__((cleanup))
>     568 |         guard(rwsem_read)(&vq->dev->rwsem);
>         |         ^
> 
> Jumping over a variable declared with the cleanup attribute does not
> prevent the cleanup function from running, it would just result in the
> variable being passed uninitialized to the cleanup function .clang
> errors instead of generating the invalid code, unlike GCC.
> 
> The jump is only present to call spin_unlock(), so convert the
> spin_lock() and spin_unlock() calls to an equivalent guard() to avoid
> the jump while leaving runtime behavior unchanged, clearing up the
> warning.
> 
> Fixes: 6c141c034c1b ("vduse: Add suspend")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Eugenio?

> ---
>  drivers/vdpa/vdpa_user/vduse_dev.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> index a257fdcb77b7..0500da043761 100644
> --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -561,9 +561,9 @@ static int vduse_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 idx,
>  
>  static void vduse_vq_kick(struct vduse_virtqueue *vq)
>  {
> -	spin_lock(&vq->kick_lock);
> +	guard(spinlock)(&vq->kick_lock);
>  	if (!vq->ready)
> -		goto unlock;
> +		return;
>  
>  	guard(rwsem_read)(&vq->dev->rwsem);
>  	if (vq->dev->suspended)
> @@ -573,8 +573,6 @@ static void vduse_vq_kick(struct vduse_virtqueue *vq)
>  		eventfd_signal(vq->kickfd);
>  	else
>  		vq->kicked = true;
> -unlock:
> -	spin_unlock(&vq->kick_lock);
>  }
>  
>  static void vduse_vq_kick_work(struct work_struct *work)
> 
> ---
> base-commit: 6c141c034c1b0b74a2ca4dd3d6fbb6d9054f6e46
> change-id: 20260610-vduse_vq_kick-fix-guard-usage-d1037c331419
> 
> Best regards,
> --  
> Cheers,
> Nathan