Re: [PATCH] KVM: x86: fix cocci warnings

From: Peter Zijlstra
Date: Mon Nov 15 2021 - 19:08:25 EST


On Mon, Nov 15, 2021 at 06:06:08PM +0100, Paolo Bonzini wrote:
> On 11/15/21 12:43, Peter Zijlstra wrote:
> > On Sun, Nov 14, 2021 at 10:13:12PM +0530, Vihas Mak wrote:
> > > change 0 to false and 1 to true to fix following cocci warnings:
> > >
> > > arch/x86/kvm/mmu/mmu.c:1485:9-10: WARNING: return of 0/1 in function 'kvm_set_pte_rmapp' with return type bool
> > > arch/x86/kvm/mmu/mmu.c:1636:10-11: WARNING: return of 0/1 in function 'kvm_test_age_rmapp' with return type bool
> >
> > That script should be deleted, it's absolute garbage.
> >
>
> Only a Sith deals in absolutes.

Is that a star-wars thingy?

In C 0 is a valid way to spell false, equally, any non-0 value is a
valid way to spell true. Why would this rate a warn?

In fact, when casting _Bool to integer, you get 0 and 1. When looking at
the memory content of the _Bool variable, you'll get 0 and 1. But we're
not allowed to write 0 and 1?