Re: [PATCH v2] [media] v4l2-async: Always unregister the subdev on failure

From: Hans Verkuil
Date: Mon Sep 05 2016 - 09:06:27 EST


Hi Alban,

On 08/24/2016 03:49 PM, Alban Bedel wrote:
> In v4l2_async_test_notify() if the registered_async callback or the
> complete notifier returns an error the subdev is not unregistered.
> This leave paths where v4l2_async_register_subdev() can fail but
> leave the subdev still registered.
>
> Add the required calls to v4l2_device_unregister_subdev() to plug
> these holes.

This patch no longer applies after another patch from Javier was merged.

Can you rebase and post a v3?

Thanks!

Hans

>
> Signed-off-by: Alban Bedel <alban.bedel@xxxxxxxxxxxxxxxxx>
> ---
> Changelog:
> v2: * Added the missing unbind() calls as suggested by Javier.
> ---
> drivers/media/v4l2-core/v4l2-async.c | 29 +++++++++++++++++------------
> 1 file changed, 17 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index ceb28d47c3f9..abe512d0b4cb 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -113,23 +113,28 @@ static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
> list_move(&sd->async_list, &notifier->done);
>
> ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
> - if (ret < 0) {
> - if (notifier->unbind)
> - notifier->unbind(notifier, sd, asd);
> - return ret;
> - }
> + if (ret < 0)
> + goto err_subdev_register;
>
> ret = v4l2_subdev_call(sd, core, registered_async);
> - if (ret < 0 && ret != -ENOIOCTLCMD) {
> - if (notifier->unbind)
> - notifier->unbind(notifier, sd, asd);
> - return ret;
> + if (ret < 0 && ret != -ENOIOCTLCMD)
> + goto err_subdev_call;
> +
> + if (list_empty(&notifier->waiting) && notifier->complete) {
> + ret = notifier->complete(notifier);
> + if (ret < 0)
> + goto err_subdev_call;
> }
>
> - if (list_empty(&notifier->waiting) && notifier->complete)
> - return notifier->complete(notifier);
> -
> return 0;
> +
> +err_subdev_call:
> + v4l2_device_unregister_subdev(sd);
> +err_subdev_register:
> + if (notifier->unbind)
> + notifier->unbind(notifier, sd, asd);
> +
> + return ret;
> }
>
> static void v4l2_async_cleanup(struct v4l2_subdev *sd)
>