From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754723Ab2DSASQ (ORCPT ); Wed, 18 Apr 2012 20:18:16 -0400 Received: from terminus.zytor.com ([198.137.202.10]:43454 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753748Ab2DSARq (ORCPT ); Wed, 18 Apr 2012 20:17:46 -0400 From: "H. Peter Anvin" To: Linux Kernel Mailing List Cc: Ingo Molnar , Thomas Gleixner , Borislav Petkov , Linus Torvalds , "H. Peter Anvin" , Glauber de Oliveira Costa Subject: [PATCH 3/5] x86, paravirt: Replace GET_CR2_INTO_RCX with GET_CR2_INTO_RAX Date: Wed, 18 Apr 2012 17:16:48 -0700 Message-Id: <1334794610-5546-4-git-send-email-hpa@zytor.com> X-Mailer: git-send-email 1.7.6.5 In-Reply-To: <1334794610-5546-1-git-send-email-hpa@zytor.com> References: <1334794610-5546-1-git-send-email-hpa@zytor.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Wed, 18 Apr 2012 17:17:26 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "H. Peter Anvin" GET_CR2_INTO_RCX is asinine: it is only used in one place, the actual paravirt call returns the value in %rax, not %rcx; and the one place that wants it wants the result in %r9. We actually generate as a result of this call: call ... movq %rax, %rcx xorq %rax, %rax /* this value isn't even used... */ movq %rcx, %r9 At least make the macro do what the paravirt call does, which is put the value into %rax. Nevermind the fact that the macro clobbers all the volatile registers. Signed-off-by: H. Peter Anvin Cc: Glauber de Oliveira Costa --- arch/x86/include/asm/paravirt.h | 6 ++---- arch/x86/kernel/head_64.S | 6 +++--- 2 files changed, 5 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index aa0f913..6cbbabf 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -1023,10 +1023,8 @@ extern void default_banner(void); call PARA_INDIRECT(pv_cpu_ops+PV_CPU_swapgs) \ ) -#define GET_CR2_INTO_RCX \ - call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2); \ - movq %rax, %rcx; \ - xorq %rax, %rax; +#define GET_CR2_INTO_RAX \ + call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2) #define PARAVIRT_ADJUST_EXCEPTION_FRAME \ PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_adjust_exception_frame), \ diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index adf52e8..d1e112c 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -23,8 +23,9 @@ #ifdef CONFIG_PARAVIRT #include #include +#define GET_CR2_INTO(reg) GET_CR2_INTO_RAX ; movq %rax, reg #else -#define GET_CR2_INTO_RCX movq %cr2, %rcx +#define GET_CR2_INTO(reg) movq %cr2, reg #endif /* we are not able to switch in one step to the final KERNEL ADDRESS SPACE @@ -286,8 +287,7 @@ ENTRY(early_idt_handler) cmpl $2,early_recursion_flag(%rip) jz 1f incl early_recursion_flag(%rip) - GET_CR2_INTO_RCX - movq %rcx,%r9 + GET_CR2_INTO(%r9) xorl %r8d,%r8d # zero for error code movl %esi,%ecx # get vector number # Test %ecx against mask of vectors that push error code. -- 1.7.6.5