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

From: Pierre-Louis Bossart
Date: Fri Aug 02 2019 - 12:52:30 EST

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

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.