Re: The sheer number of sparse warnings in the kernel

H. Peter Anvin
2014-02-27T00:11:40Z

On 02/26/2014 03:28 PM, Greg KH wrote:
>>
>> What do we need to do to actually make our tools be able to do work for
>> us? Newbie projects to clean up? Trying to get the larger Linux
>> companies to put resources on it?
>
> It's not the easiest "newbie" project as usually the first reflex to
> "just cast it away" is wrong for a lot of sparse warnings. I know this
> from people trying to fix up the sparse warnings in drivers/staging/
>

I have seen this phenomenon, too. I also see a bunch of sparse warnings
which are clearly bogus, for example complaining about sizeof(bool) when
in bits like:

__this_cpu_write(swallow_nmi, false);

So getting this to the point where it is genuinely useful and can be
made a ubiquitous part of the Linux development process is going to take
more work and probably involve improvements to sparse so we can indicate
in the kernel sources when something is okay or removing completely
bogus warnings, and so on.

The bigger question, again, is what do we need to do to make this
happen, assuming it is worth doing? We certainly have had bugs,
including security holes, which sparse would have caught. At the same
time, this kind of work tends to not be the kind that attract the top
hackers, unfortunately, as it is not "fun".

-hpa