Re: [BUG] [5.15] Compilation error in arch/x86/kvm/mmu/spte.h with clang-14

From: torvic9
Date: Mon Oct 04 2021 - 05:30:47 EST



> Paolo Bonzini <pbonzini@xxxxxxxxxx> hat am 04.10.2021 11:26 geschrieben:
>
>
> On 04/10/21 11:08, torvic9@xxxxxxxxxxx wrote:
> > I encounter the following issue when compiling 5.15-rc4 with clang-14:
> >
> > In file included from arch/x86/kvm/mmu/mmu.c:27:
> > arch/x86/kvm/mmu/spte.h:318:9: error: use of bitwise '|' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
> > return __is_bad_mt_xwr(rsvd_check, spte) |
> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > ||
> > arch/x86/kvm/mmu/spte.h:318:9: note: cast one or both operands to int to silence this warning
>
> The warning is wrong, as mentioned in the line right above:

So it's an issue with clang-14 then?
(I add Nick and Nathan)

>
> /*
> * Use a bitwise-OR instead of a logical-OR to aggregate the reserved
> * bits and EPT's invalid memtype/XWR checks to avoid an extra Jcc
> * (this is extremely unlikely to be short-circuited as true).
> */
>
> Paolo