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

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Message-ID: <c4894cbd-4e4f-74a1-6fe0-6f3c264f297e@redhat.com>
Date:   Wed, 22 Aug 2018 19:07:41 +0200
From:   David Hildenbrand <david@...hat.com>
To:     Pierre Morel <pmorel@...ux.ibm.com>
Cc:     linux-kernel@...r.kernel.org, cohuck@...hat.com,
        linux-s390@...r.kernel.org, kvm@...r.kernel.org,
        frankja@...ux.ibm.com, akrowiak@...ux.ibm.com,
        borntraeger@...ibm.com, schwidefsky@...ibm.com,
        heiko.carstens@...ibm.com
Subject: Re: [PATCH v2 4/5] KVM: s390: vsie: Always test the crycbd for NULL

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)

Either we return or we check for !crycb_addr

> 
> Signed-off-by: Pierre Morel <pmorel@...ux.ibm.com>
> ---
>  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 */
> 


-- 

Thanks,

David / dhildenb