[PATCH v1 0/3] ASoC: Add bounds checking for written values

[Takashi Iwai]

On Mon, 24 Jan 2022 17:52:46 +0100,
Mark Brown wrote:
> 
> On Mon, Jan 24, 2022 at 05:29:50PM +0100, Jaroslav Kysela wrote:
> > On 24. 01. 22 16:32, Mark Brown wrote:
> 
> > > This series adds verification that values written to registers are in
> > > bounds for controls since the core doesn't validate for us.
> 
> > As discussed, those conditions should be optional to eventually catch the
> > wrong applications. I don't see any benefit to report the range error back
> > when there is value masking code already. The users will note when the
> > unwanted values are written to the hardware, or not?
> 
> In general I'd say that silent failures are harder to work with than
> returning an error at the point where we notice that there's a problem,
> assuming userspace is paying any attention to the error return at all of
> course.  We certainly have quite a lot of existing put() methods that do
> return errors and it's not like the application isn't invoking undefined
> behaviour so I don't see a problem here.

I find also it's more useful to have the proper checks in general.

Jaroslav, is you concern only about the compatibility of user-space?
Or anything else?  The compatibility is always certainly a slight
issue; if this breaks really something useful and actually working
stuff, we need to consider the workaround...


thanks,

Takashi