Re: [PATCH v2 12/12] media: mc: Check pad flag validity

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Sakari,

Thank you for the patch.

On Mon, Sep 18, 2023 at 03:51:38PM +0300, Sakari Ailus wrote:
> Check the validity of pad flags on entity init. Exactly one of the flags
> must be set.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
>  drivers/media/mc/mc-entity.c | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
> index 83468d4a440b..38d5bbae33d7 100644
> --- a/drivers/media/mc/mc-entity.c
> +++ b/drivers/media/mc/mc-entity.c
> @@ -195,8 +195,9 @@ int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
>  			   struct media_pad *pads)
>  {
>  	struct media_device *mdev = entity->graph_obj.mdev;
> -	struct media_pad *iter;
> +	struct media_pad *iter, *iter2;
>  	unsigned int i = 0;
> +	int ret = 0;
>  
>  	if (num_pads >= MEDIA_ENTITY_MAX_PADS)
>  		return -E2BIG;
> @@ -210,15 +211,30 @@ int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
>  	media_entity_for_each_pad(entity, iter) {
>  		iter->entity = entity;
>  		iter->index = i++;
> +
> +		if (hweight32(iter->flags & (MEDIA_PAD_FL_SINK |
> +					     MEDIA_PAD_FL_SOURCE)) != 1) {
> +			ret = -EINVAL;
> +			break;
> +		}
> +
>  		if (mdev)
>  			media_gobj_create(mdev, MEDIA_GRAPH_PAD,
>  					  &iter->graph_obj);
>  	}
>  
> +	if (ret && mdev) {
> +		media_entity_for_each_pad(entity, iter2) {
> +			if (iter2 == iter)
> +				break;
> +			media_gobj_destroy(&iter->graph_obj);

Wrong iterator.

Instead of using a second iterator, which can be error-prone as shown
here, how about breaking when !iter->graph_obj.mdev, which indicates an
uninitialized object ?

> +		}
> +	}
> +
>  	if (mdev)
>  		mutex_unlock(&mdev->graph_mutex);
>  
> -	return 0;
> +	return ret;
>  }
>  EXPORT_SYMBOL_GPL(media_entity_pads_init);
>  

-- 
Regards,

Laurent Pinchart