Re: [PATCH 6/7] drm: rcar-du: fix possible object reference leak

[Laurent Pinchart]

Hi Wen,

Thank you for the patch.

On Thu, Apr 04, 2019 at 12:04:14AM +0800, Wen Yang wrote:
> The call to of_get_parent returns a node pointer with refcount
> incremented thus it must be explicitly decremented after the last
> usage.
> 
> Detected by coccinelle with the following warnings:
> drivers/gpu/drm/rcar-du/rcar_du_of.c:235:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 216, but without a corresponding object release within this function.
> drivers/gpu/drm/rcar-du/rcar_du_of.c:236:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 209, but without a corresponding object release within this function.
> 
> Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Cc: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx (open list)
> ---
>  drivers/gpu/drm/rcar-du/rcar_du_of.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_of.c b/drivers/gpu/drm/rcar-du/rcar_du_of.c
> index afef696..30bceca 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_of.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_of.c
> @@ -232,6 +232,8 @@ static void __init rcar_du_of_lvds_patch(const struct of_device_id *of_ids)
>  	lvds_node = of_find_compatible_node(NULL, NULL, compatible);
>  	if (lvds_node) {
>  		of_node_put(lvds_node);
> +		of_node_put(soc_node);
> +		of_node_put(du_node);
>  		return;

Wouldn't it be simpler to just turn the return into a goto done ?

>  	}
>  

-- 
Regards,

Laurent Pinchart