From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753322Ab0AGQsM (ORCPT ); Thu, 7 Jan 2010 11:48:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753306Ab0AGQsL (ORCPT ); Thu, 7 Jan 2010 11:48:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:63195 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753230Ab0AGQsJ (ORCPT ); Thu, 7 Jan 2010 11:48:09 -0500 Message-ID: <4B460664.1090006@redhat.com> Date: Thu, 07 Jan 2010 18:05:56 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Thunderbird/3.0 MIME-Version: 1.0 To: Roel Kluin CC: Marcelo Tosatti , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kvm: don't treat NULL parent_pte as multimapped in mmu_parent_walk() References: <4B460441.6090602@gmail.com> In-Reply-To: <4B460441.6090602@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > --- > 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