Re: [PATCH] arm64: kvm: Delete duplicated label: in invalid_vector

From: Marc Zyngier
Date: Tue Apr 14 2020 - 09:57:24 EST


Hi Nick,

On Mon, 13 Apr 2020 16:37:10 -0700
Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote:

> On Mon, Apr 13, 2020 at 4:10 PM Fangrui Song <maskray@xxxxxxxxxx> wrote:
> >
> > SYM_CODE_START defines \label , so it is redundant to define \label again.
> > A redefinition at the same place is accepted by GNU as
> > (https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=159fbb6088f17a341bcaaac960623cab881b4981)
> > but rejected by the clang integrated assembler.
> >
> > Fixes: 617a2f392c92 ("arm64: kvm: Annotate assembly using modern annoations")
>
> Thanks for the patch! I think a more accurate Fixes tag would be:
> Fixes: 2b28162cf65a ("arm64: KVM: HYP mode entry points")

I'm not sure this commit is accurate. At that time, there was no other
declaration for \label and dropping it would simply break compilation.
I believe that Fangrui is correct in his analysis that 617a2f392c92 is
the first broken commit.

> With this patch applied, and your other arm64 integrated assembler
> patch (https://lore.kernel.org/linux-arm-kernel/20200413033811.75074-1-maskray@xxxxxxxxxx/T/#u),
> I can now assemble arch/arm64/kvm/.

Progress! ;-)

> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
>
> > Link: https://github.com/ClangBuiltLinux/linux/issues/988
> > Signed-off-by: Fangrui Song <maskray@xxxxxxxxxx>
> > ---
> > arch/arm64/kvm/hyp/hyp-entry.S | 1 -
> > 1 file changed, 1 deletion(-)
> >
> > diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
> > index c2a13ab3c471..9c5cfb04170e 100644
> > --- a/arch/arm64/kvm/hyp/hyp-entry.S
> > +++ b/arch/arm64/kvm/hyp/hyp-entry.S
> > @@ -198,7 +198,6 @@ SYM_CODE_END(__hyp_panic)
> > .macro invalid_vector label, target = __hyp_panic
> > .align 2
> > SYM_CODE_START(\label)
> > -\label:
> > b \target
> > SYM_CODE_END(\label)
> > .endm
> > --
> > 2.26.0.110.g2183baf09c-goog
> >
>
>

I'll pick this up as soon as we've sorted the queue with the rest of
the fixes.

Thanks,

M.
--
Jazz is not dead. It just smells funny...