Re: [PATCH 1/2] KVM: Silence underflow warning in avic_get_physical_id_entry()

[Joerg Roedel <joro@8bytes.org>]

On Thu, May 18, 2017 at 10:38:53AM +0300, Dan Carpenter wrote:
> Smatch complains that we check cap the upper bound of "index" but don't
> check for negatives.  It's a false positive because "index" is never
> negative.  But it's also simple enough to make it unsigned which makes
> the code easier to audit.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index c27ac6923a18..183ddb235fb4 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -1272,7 +1272,8 @@ static void init_vmcb(struct vcpu_svm *svm)
>  
>  }
>  
> -static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu, int index)
> +static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu,
> +				       unsigned int index)

I would have used 'unsigned', just to annoy checkpatch. But I guess
this is ok too :)


	Joerg