Re: [PATCH v2 4/5] KVM: s390: vsie: Always test the crycbd for NULL

[Pierre Morel]

On 22/08/2018 19:07, David Hildenbrand wrote:
> On 22.08.2018 18:51, Pierre Morel wrote:
> > BUG: the crycbd must be tested for null even if
> > not crossing a page boundary (which will never
> > occur in this case anyway).
>
> I don't see the BUG. Can you elaborate? (maybe it is too late for me)

No it was too late for me :)
The BUG was by me, my brain was fooled by the "else"
there is not problem there.
CRCBD is always tested.

Sorry.

> Either we return or we check for !crycb_addr
>
> > Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
> > ---
> >   arch/s390/kvm/vsie.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
> > index 0b12916..7ee4329 100644
> > --- a/arch/s390/kvm/vsie.c
> > +++ b/arch/s390/kvm/vsie.c
> > @@ -172,7 +172,7 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
> >   
> >   	if ((crycb_addr & PAGE_MASK) != ((crycb_addr + 128) & PAGE_MASK))
> >   		return set_validity_icpt(scb_s, 0x003CU);
> > -	else if (!crycb_addr)
> > +	if (!crycb_addr)
> >   		return set_validity_icpt(scb_s, 0x0039U);
> >   
> >   	/* copy only the wrapping keys */


--
Pierre Morel
Linux/KVM/QEMU in BÃblingen - Germany