Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753594AbZAaHRd (ORCPT ); Sat, 31 Jan 2009 02:17:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751754AbZAaHRZ (ORCPT ); Sat, 31 Jan 2009 02:17:25 -0500 Received: from gw.goop.org ([64.81.55.164]:40920 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751736AbZAaHRY (ORCPT ); Sat, 31 Jan 2009 02:17:24 -0500 Message-ID: <4983FB03.9030001@goop.org> Date: Fri, 30 Jan 2009 23:17:23 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: "H. Peter Anvin" CC: Ingo Molnar , linux-kernel@vger.kernel.org, Xen-devel , the arch/x86 maintainers , Ian Campbell , Zachary Amsden , Rusty Russell , Ravikiran Thirumalai Subject: [PATCH 1/2] x86/paravirt: don't restore second return reg References: <49815764.6040809@kernel.org> <49817C26.2020503@goop.org> <4983DBC9.5080701@kernel.org> In-Reply-To: <4983DBC9.5080701@kernel.org> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1145 Lines: 32 Impact: bugfix In the 32-bit calling convention, %eax:%edx is used to return 64-bit values. Don't save and restore %edx around wrapped functions, or they can't return a full 64-bit result. Signed-off-by: Jeremy Fitzhardinge --- arch/x86/include/asm/paravirt.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) =================================================================== --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -1522,8 +1522,8 @@ #define PV_RESTORE_REGS "popl %edx; popl %ecx;" /* save and restore all caller-save registers, except return value */ -#define PV_SAVE_ALL_CALLER_REGS PV_SAVE_REGS -#define PV_RESTORE_ALL_CALLER_REGS PV_RESTORE_REGS +#define PV_SAVE_ALL_CALLER_REGS "pushl %ecx;" +#define PV_RESTORE_ALL_CALLER_REGS "popl %ecx;" #define PV_FLAGS_ARG "0" #define PV_EXTRA_CLOBBERS -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/