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* [PATCH] kvm: don't treat NULL parent_pte as multimapped in mmu_parent_walk()
@ 2010-01-07 15:56 Roel Kluin
  2010-01-07 16:05 ` Avi Kivity
  0 siblings, 1 reply; 2+ messages in thread
From: Roel Kluin @ 2010-01-07 15:56 UTC (permalink / raw)
  To: Avi Kivity, Marcelo Tosatti, Thomas Gleixner, Ingo Molnar,
	H. Peter Anvin, x86, kvm, linux-kernel

If a kvm_mmu_page is not multimapped but parent_pte is NULL
don't treat it as multimapped and dereference it.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
This wasn't tested and maybe I misunderstood so please review.

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 4c3e5b2..eb17287 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1031,10 +1031,12 @@ static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 	struct kvm_mmu_page *parent_sp;
 	int i;
 
-	if (!sp->multimapped && sp->parent_pte) {
-		parent_sp = page_header(__pa(sp->parent_pte));
-		fn(vcpu, parent_sp);
-		mmu_parent_walk(vcpu, parent_sp, fn);
+	if (!sp->multimapped) {
+		if (sp->parent_pte) {
+			parent_sp = page_header(__pa(sp->parent_pte));
+			fn(vcpu, parent_sp);
+			mmu_parent_walk(vcpu, parent_sp, fn);
+		}
 		return;
 	}
 	hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] kvm: don't treat NULL parent_pte as multimapped in mmu_parent_walk()
  2010-01-07 15:56 [PATCH] kvm: don't treat NULL parent_pte as multimapped in mmu_parent_walk() Roel Kluin
@ 2010-01-07 16:05 ` Avi Kivity
  0 siblings, 0 replies; 2+ messages in thread
From: Avi Kivity @ 2010-01-07 16:05 UTC (permalink / raw)
  To: Roel Kluin
  Cc: Marcelo Tosatti, Thomas Gleixner, Ingo Molnar, H. Peter Anvin,
	x86, kvm, linux-kernel

On 01/07/2010 05:56 PM, Roel Kluin wrote:
> If a kvm_mmu_page is not multimapped but parent_pte is NULL
> don't treat it as multimapped and dereference it.
>
> Signed-off-by: Roel Kluin<roel.kluin@gmail.com>
> ---
> This wasn't tested and maybe I misunderstood so please review.
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 4c3e5b2..eb17287 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -1031,10 +1031,12 @@ static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
>   	struct kvm_mmu_page *parent_sp;
>   	int i;
>
> -	if (!sp->multimapped&&  sp->parent_pte) {
> -		parent_sp = page_header(__pa(sp->parent_pte));
> -		fn(vcpu, parent_sp);
> -		mmu_parent_walk(vcpu, parent_sp, fn);
> +	if (!sp->multimapped) {
> +		if (sp->parent_pte) {
> +			parent_sp = page_header(__pa(sp->parent_pte));
> +			fn(vcpu, parent_sp);
> +			mmu_parent_walk(vcpu, parent_sp, fn);
> +		}
>   		return;
>   	}
>   	hlist_for_each_entry(pte_chain, node,&sp->parent_ptes, link)
>
>    

If sp->parent_pte is NULL then the list walk terminates immediately.

-- 
error compiling committee.c: too many arguments to function


^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2010-01-07 16:48 UTC | newest]

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2010-01-07 16:05 ` Avi Kivity

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