From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760547AbZIPWoe (ORCPT ); Wed, 16 Sep 2009 18:44:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933596AbZIPWoW (ORCPT ); Wed, 16 Sep 2009 18:44:22 -0400 Received: from kroah.org ([198.145.64.141]:55383 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760239AbZIPWkO (ORCPT ); Wed, 16 Sep 2009 18:40:14 -0400 X-Mailbox-Line: From gregkh@mini.kroah.org Wed Sep 16 15:37:18 2009 Message-Id: <20090916223718.433647359@mini.kroah.org> User-Agent: quilt/0.48-1 Date: Wed, 16 Sep 2009 15:36:48 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Glauber Costa , Avi Kivity Subject: [patch 35/45] KVM guest: fix bogus wallclock physical address calculation References: <20090916223613.597295240@mini.kroah.org> Content-Disposition: inline; filename=kvm-guest-fix-bogus-wallclock-physical-address-calculation.patch In-Reply-To: <20090916223739.GA4789@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Glauber Costa commit a20316d2aa41a8f4fd171648bad8f044f6060826 upstream. The use of __pa() to calculate the address of a C-visible symbol is wrong, and can lead to unpredictable results. See arch/x86/include/asm/page.h for details. It should be replaced with __pa_symbol(), that does the correct math here, by taking relocations into account. This ensures the correct wallclock data structure physical address is passed to the hypervisor. Signed-off-by: Glauber Costa Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/kvmclock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -50,8 +50,8 @@ static unsigned long kvm_get_wallclock(v struct timespec ts; int low, high; - low = (int)__pa(&wall_clock); - high = ((u64)__pa(&wall_clock) >> 32); + low = (int)__pa_symbol(&wall_clock); + high = ((u64)__pa_symbol(&wall_clock) >> 32); native_write_msr(MSR_KVM_WALL_CLOCK, low, high); vcpu_time = &get_cpu_var(hv_clock);