[alsa-devel] [PATCH 03/14] ALSA: Add a helper to initialize device

[Lars-Peter Clausen]

On 02/02/2015 11:24 AM, Takashi Iwai wrote:
> diff --git a/sound/core/init.c b/sound/core/init.c
> index 074875d68c15..2f730efe97b6 100644
> --- a/sound/core/init.c
> +++ b/sound/core/init.c
> @@ -157,6 +157,25 @@ static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
>   	return mask; /* unchanged */
>   }
>
> +static void default_release(struct device *dev)
> +{
> +}

A empty release callback is pretty much always wrong and typically causes 
use-after-free bugs. It might be correct in this case, but there should at 
least be a comment explaining why it is correct. And on the long run things 
should probably be re-factored to do all memory freeing in a subdevice 
specific release function.

- Lars