Re: [PATCH 4/4] x86/percpu: Use C for percpu read/write accessors

[Uros Bizjak]

On Mon, Oct 9, 2023 at 1:41 PM Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
>
> * Uros Bizjak <ubizjak@xxxxxxxxx> wrote:
>
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > index ecb256954351..1edf4a5b93ca 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -2393,7 +2393,7 @@ config CC_HAS_NAMED_AS
> >
> >  config USE_X86_SEG_SUPPORT
> >       def_bool y
> > -     depends on CC_HAS_NAMED_AS && SMP
> > +     depends on CC_HAS_NAMED_AS && SMP && !KASAN
> > +     depends on CC_HAS_NAMED_AS && SMP && !KASAN
>
> So I'd rather express this as a Kconfig quirk line, and explain each quirk.
>
> Something like:
>
>         depends on CC_HAS_NAMED_AS
>         depends on SMP
>         #
>         # -fsanitize=kernel-address (KASAN) is at the moment incompatible
>         # with named address spaces - see GCC bug #12345.
>         #
>         depends on !KASAN
>
> ... or so.
>
> BTW., please also document the reason why !SMP is excluded.

Eh, thanks for pointing it out, it is not needed at all, it works also
for !SMP. Will fix in a Kconfig patch.

Thanks,
Uros.