From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: [patch] KVM: fix hypercall cache/decache Date: Tue, 20 Mar 2007 09:54:27 +0100 Message-ID: <20070320085427.GA21948@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Avi Kivity Return-path: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Subject: [patch] KVM: fix hypercall cache/decache From: Ingo Molnar a recent change to kvm_hypercall() flipped around the order of ->cache_regs() and ->decache_regs(), but that is bogus and causes ESP/RIP corruption: ->cache_regs() will 'cache' the CPU-side registers into the vcpu structure, and ->decache_regs() will sync it back to the CPU. fix this by using the correct order again. Signed-off-by: Ingo Molnar --- drivers/kvm/kvm_main.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) Index: linux/drivers/kvm/kvm_main.c =================================================================== --- linux.orig/drivers/kvm/kvm_main.c +++ linux/drivers/kvm/kvm_main.c @@ -1177,7 +1177,7 @@ int kvm_hypercall(struct kvm_vcpu *vcpu, { unsigned long nr, a0, a1, a2, a3, a4, a5, ret; - kvm_arch_ops->decache_regs(vcpu); + kvm_arch_ops->cache_regs(vcpu); ret = -KVM_EINVAL; #ifdef CONFIG_X86_64 if (is_long_mode(vcpu)) { @@ -1204,7 +1204,8 @@ int kvm_hypercall(struct kvm_vcpu *vcpu, ; } vcpu->regs[VCPU_REGS_RAX] = ret; - kvm_arch_ops->cache_regs(vcpu); + kvm_arch_ops->decache_regs(vcpu); + return 1; } EXPORT_SYMBOL_GPL(kvm_hypercall); ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV