Hi Laurent,
Thanks for your work.
On 2020-08-11 23:59:38 +0300, Laurent Pinchart wrote:
> v4l2_async_notifier_add_subdev() requires the asd to be allocated
> dynamically, but the rcar-csi2 driver embeds it in the rcar_csi2
> structure. This causes memory corruption when the notifier is destroyed
> at remove time with v4l2_async_notifier_cleanup().
>
> Fix this issue by registering the asd with
> v4l2_async_notifier_add_fwnode_subdev(), which allocates it dynamically
> internally.
This patch conflicts with [1] which I think is a nicer solution to the
problem, provided 1/2 of that series is palatable for everyone :-)
1. [PATCH 2/2] rcar-csi2: Use V4L2 async helpers to create the notifier
>
> Fixes: 769afd212b16 ("media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver driver")
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/platform/rcar-vin/rcar-csi2.c | 24 +++++++++------------
> 1 file changed, 10 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
> index c6cc4f473a07..a16c492b3143 100644
> --- a/drivers/media/platform/rcar-vin/rcar-csi2.c
> +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
> @@ -362,7 +362,6 @@ struct rcar_csi2 {
> struct media_pad pads[NR_OF_RCAR_CSI2_PAD];
>
> struct v4l2_async_notifier notifier;
> - struct v4l2_async_subdev asd;
> struct v4l2_subdev *remote;
>
> struct v4l2_mbus_framefmt mf;
> @@ -811,6 +810,8 @@ static int rcsi2_parse_v4l2(struct rcar_csi2 *priv,
>
> static int rcsi2_parse_dt(struct rcar_csi2 *priv)
> {
> + struct v4l2_async_subdev *asd;
> + struct fwnode_handle *fwnode;
> struct device_node *ep;
> struct v4l2_fwnode_endpoint v4l2_ep = { .bus_type = 0 };
> int ret;
> @@ -834,24 +835,19 @@ static int rcsi2_parse_dt(struct rcar_csi2 *priv)
> return ret;
> }
>
> - priv->asd.match.fwnode =
> - fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
> - priv->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
> -
> + fwnode = fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
> of_node_put(ep);
>
> + dev_dbg(priv->dev, "Found '%pOF'\n", to_of_node(fwnode));
> +
> v4l2_async_notifier_init(&priv->notifier);
> -
> - ret = v4l2_async_notifier_add_subdev(&priv->notifier, &priv->asd);
> - if (ret) {
> - fwnode_handle_put(priv->asd.match.fwnode);
> - return ret;
> - }
> -
> priv->notifier.ops = &rcar_csi2_notify_ops;
>
> - dev_dbg(priv->dev, "Found '%pOF'\n",
> - to_of_node(priv->asd.match.fwnode));
> + asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier, fwnode,
> + sizeof(*asd));
> + fwnode_handle_put(fwnode);
> + if (IS_ERR(asd))
> + return PTR_ERR(asd);
>
> ret = v4l2_async_subdev_notifier_register(&priv->subdev,
> &priv->notifier);
> --
> Regards,
>
> Laurent Pinchart
>
--
Regards,
Niklas Söderlund
