On Thu, Oct 10, 2019 at 03:13:30PM +0200, Johan Hovold wrote:
> If a process is interrupted while accessing the "gpu" debugfs file and
> the drm device struct_mutex is contended, release() could return early
> and fail to free related resources.
>
> Note that the return value from release() is ignored.
>
> Fixes: 4f776f4511c7 ("drm/msm/gpu: Convert the GPU show function to use the GPU state")
> Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.18
> Cc: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
> Cc: Rob Clark <robdclark@xxxxxxxxx>
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> ---
Rob, Sean,
Sending a reminder about this one, which is not yet in linux-next.
Perhaps Daniel can pick it up otherwise?
Thanks,
Johan
> drivers/gpu/drm/msm/msm_debugfs.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
> index 6be879578140..1c74381a4fc9 100644
> --- a/drivers/gpu/drm/msm/msm_debugfs.c
> +++ b/drivers/gpu/drm/msm/msm_debugfs.c
> @@ -47,12 +47,8 @@ static int msm_gpu_release(struct inode *inode, struct file *file)
> struct msm_gpu_show_priv *show_priv = m->private;
> struct msm_drm_private *priv = show_priv->dev->dev_private;
> struct msm_gpu *gpu = priv->gpu;
> - int ret;
> -
> - ret = mutex_lock_interruptible(&show_priv->dev->struct_mutex);
> - if (ret)
> - return ret;
>
> + mutex_lock(&show_priv->dev->struct_mutex);
> gpu->funcs->gpu_state_put(show_priv->state);
> mutex_unlock(&show_priv->dev->struct_mutex);
