Re: [PATCH v1 2/2] drm/panfrost: Fix wait_bo ioctl leaking positive return from dma_resv_wait_timeout()

[Boris Brezillon]

On Sun, 19 Apr 2026 16:17:16 +0900
Gyeyoung Baek <gye976@xxxxxxxxx> wrote:

> dma_resv_wait_timeout() returns a positive 'remaining jiffies' value
> on success, 0 on timeout, and -errno on failure.
> 
> panfrost_ioctl_wait_bo() returns this 'long' result from an int-typed
> ioctl handler, so positive values reach userspace as bogus errors.
> Explicitly set ret to 0 on the success path.
> 
> Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Gyeyoung Baek <gye976@xxxxxxxxx>

Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>

> ---
>  drivers/gpu/drm/panfrost/panfrost_drv.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index 3d0bdba2a..784e36d72 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -390,6 +390,8 @@ panfrost_ioctl_wait_bo(struct drm_device *dev, void *data,
>  				    true, timeout);
>  	if (!ret)
>  		ret = timeout ? -ETIMEDOUT : -EBUSY;
> +	else if (ret > 0)
> +		ret = 0;
>  
>  	drm_gem_object_put(gem_obj);
>