Hi Hans,
Thanks for the patch.
On Fri, Feb 23, 2024 at 09:46:19AM +0100, Hans Verkuil wrote:
> First the media device node was created, and if successful it was
> marked as 'registered'. This leaves a small race condition where
> an application can open the device node and get an error back
> because the 'registered' flag was not yet set.
>
> Change the order: first set the 'registered' flag, then actually
> register the media device node. If that fails, then clear the flag.
>
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> drivers/media/mc/mc-devnode.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c
> index 7f67825c8757..318e267e798e 100644
> --- a/drivers/media/mc/mc-devnode.c
> +++ b/drivers/media/mc/mc-devnode.c
> @@ -245,15 +245,14 @@ int __must_check media_devnode_register(struct media_device *mdev,
> kobject_set_name(&devnode->cdev.kobj, "media%d", devnode->minor);
>
> /* Part 3: Add the media and char device */
> + set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
> ret = cdev_device_add(&devnode->cdev, &devnode->dev);
> if (ret < 0) {
> + clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
> pr_err("%s: cdev_device_add failed\n", __func__);
> goto cdev_add_error;
> }
>
> - /* Part 4: Activate this minor. The char device can now be used. */
> - set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
> -
> return 0;
>
> cdev_add_error:
--
Kind regards,
Sakari Ailus
