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

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

[Dan Carpenter]

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)
 {
 	u64 *avic_physical_id_table;
 	struct kvm_arch *vm_data = &vcpu->kvm->arch;

[PATCH 2/2] KVM: Tidy the whitespace in nested_svm_check_permissions()

[Dan Carpenter]

I moved the || to the line before.  Also I replaced some spaces with a
tab on the "return 0;" line.  It looks OK in the diff but originally
that line was only indented 7 spaces.

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..226954f8106f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2370,8 +2371,8 @@ static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)
 
 static int nested_svm_check_permissions(struct vcpu_svm *svm)
 {
-	if (!(svm->vcpu.arch.efer & EFER_SVME)
-	    || !is_paging(&svm->vcpu)) {
+	if (!(svm->vcpu.arch.efer & EFER_SVME) ||
+	    !is_paging(&svm->vcpu)) {
 		kvm_queue_exception(&svm->vcpu, UD_VECTOR);
 		return 1;
 	}
@@ -2381,7 +2382,7 @@ static int nested_svm_check_permissions(struct vcpu_svm *svm)
 		return 1;
 	}
 
-       return 0;
+	return 0;
 }
 
 static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,

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

[Joerg Roedel]

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

Re: [PATCH 2/2] KVM: Tidy the whitespace in nested_svm_check_permissions()

[Joerg Roedel]

On Thu, May 18, 2017 at 10:39:53AM +0300, Dan Carpenter wrote:
> I moved the || to the line before.  Also I replaced some spaces with a
> tab on the "return 0;" line.  It looks OK in the diff but originally
> that line was only indented 7 spaces.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Acked-by: Joerg Roedel <jroedel@suse.de>