Re: [PATCH v3 2/2] x86: Fix /proc/cpuinfo cpumask warning

Andrew Jones
2022-10-31T08:06:12Z

On Fri, Oct 28, 2022 at 06:06:41PM +0200, Borislav Petkov wrote:
> On Fri, Oct 28, 2022 at 10:13:28AM -0500, Yury Norov wrote:
> > Because it's related to bitmap API usage and has been revealed after
> > some work in bitmaps.
>
> So first of all, that "fix" needs to explain what exactly it is fixing.
> Not "it fixes this and that warning" but why the input arg to
> cpumask_next() cannot be nr_cpu_ids because... yadda yadda...

Hi Boris,

I didn't realize you were still looking for improvements to the commit
message for this patch. I could add something like,

The valid cpumask range is [0, nr_cpu_ids) and cpumask_next() always
returns a CPU ID greater than its input, which results in its input
range being [-1, nr_cpu_ids - 1). Ensure showing CPU info avoids
triggering error conditions in cpumask_next() by stopping its loop
over CPUs when its input would be invalid.

Thanks,
drew

>
> > And because nobody else cares.
>
> Why do you assume that?
>
> > If you're willing to move it yourself please go ahead.
>
> If it fixes a real issue, we are taking it. And pls note that x86
> patches go through the tip tree.
>
> Thx.
>
> --
> Regards/Gruss,
> Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette