Re: [PATCH 00/35] media: Fix coccinelle warning/errors

Laurent Pinchart
2024-04-17T15:51:24Z

On Tue, Apr 16, 2024 at 11:47:17AM +0300, Dan Carpenter wrote:
> In my opinion, it's better to just ignore old warnings.

I agree. Whatever checkers we enable, whatever code we test, there will
always be false positives. A CI system needs to be able to ignore those
false positives and only warn about new issues.

> When code is new the warnings are going to be mostly correct. The
> original author is there and knows what the code does. Someone has
> the hardware ready to test any changes. High value, low burden.
>
> When the code is old only the false positives are left. No one is
> testing the code. It's low value, high burden.
>
> Plus it puts static checker authors in a difficult place because now
> people have to work around our mistakes. It creates animosity.
>
> Now we have to hold ourselves to a much higher standard for false
> positives. It sounds like I'm complaining and lazy, right? But Oleg
> Drokin has told me previously that I spend too much time trying to
> silence false positives instead of working on new code. He's has a
> point which is that actually we have limited amount of time and we have
> to make choices about what's the most useful thing we can do.
>
> So what I do and what the zero day bot does is we look at warnings one
> time and we re-review old warnings whenever a file is changed.
>
> Kernel developers are very good at addressing static checker warnings
> and fixing the real issues... People sometimes ask me to create a
> database of warnings which I have reviewed but the answer is that
> anything old can be ignored. As I write this, I've had a thought that
> instead of a database of false positives maybe we should record a
> database of real bugs to ensure that the fixes for anything real is
> applied.

--
Regards,

Laurent Pinchart