Messages in this thread | | | From | Yury Norov <> | Date | Tue, 11 Oct 2022 12:02:26 -0700 | Subject | Re: [PATCH] x86: Fix /proc/cpuinfo cpumask warning |
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On Tue, Oct 11, 2022 at 11:17 AM Andrew Jones <ajones@ventanamicro.com> wrote: > > On Tue, Oct 11, 2022 at 08:01:03PM +0200, Borislav Petkov wrote: > > On Tue, Oct 11, 2022 at 07:50:31PM +0200, Andrew Jones wrote: > > > Upcoming cpumask changes will start issuing warnings[*] when cpu > > > > What upcoming changes? > > > > This needs a concrete pointer to a commit or so. > > Hi Boris, > > Sorry, I should have pointed this out. The upcoming change is > > linux-next/master commit a314123c8bdb ("cpumask: fix checking valid cpu > range") > > And also an ongoing discussion here > https://lore.kernel.org/lkml/20221011170949.upxk3tcfcwnkytwm@kamzik/ > > I'm hoping that Yury will pick these patches up and integrate > them at the front of his series when introducing the warnings. > I wasn't sure how to call that out other than with the generic > "upcoming change". > > > > > > indices equal to nr_cpu_ids are passed to cpumask_next* functions. > > > > How do those indices get passed here? I think you need to explain how > > exactly this happens.
The cpumask_check() fix is already in master. Because of some mess in cpumask, cpumask_check() was broken for quite a long time, and didn't bark when passed with an out-of-range CPU.
I fixed some false-positives and sent those fixes together with a314123c8bdb. Now, I expect that people will see warnings generated by correct cpumask_check(). This is actually the first sign.
Andrew, can you please answer Borislav's question:
> > How do those indices get passed here? I think you need to explain how > > exactly this happens.
It might be either an expected behaviour, and then there should be a great explanation on how and why things work in the subsystem.
Or it might be an error in the caller. In that case, the caller must be fixed.
Thanks, Yury
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