Re: [alsa-devel] [RFC PATCH 06/40] soundwire: intel: prevent possible dereference in hw_params

[Pierre-Louis Bossart]

On 8/2/19 10:57 AM, Vinod Koul wrote:
> On 02-08-19, 10:16, Pierre-Louis Bossart wrote:
> > On 8/2/19 6:55 AM, Vinod Koul wrote:
> > > On 25-07-19, 18:39, Pierre-Louis Bossart wrote:
> > > > This should not happen in production systems but we should test for
> > > > all callback arguments before invoking the config_stream callback.
> > >
> > > so you are saying callback arg is mandatory, if so please document that
> > > assumption
> >
> > no, what this says is that if a config_stream is provided then it needs to
> > have a valid argument.
>
> well typically args are not mandatory..
>
> > I am not sure what you mean by "document that assumption", comment in the
> > code (where?) or SoundWire documentation?
>
> The callback documentation which in this is in include/linux/soundwire/sdw_intel.h

/**
 * struct sdw_intel_ops: Intel audio driver callback ops
 *
 * @config_stream: configure the stream with the hw_params
 */
struct sdw_intel_ops {
	int (*config_stream)(void *arg, void *substream,
			     void *dai, void *hw_params, int stream_num);
};

all parameters are mandatory really, not sure what you are trying to get at.