From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754193AbZKPWHH (ORCPT ); Mon, 16 Nov 2009 17:07:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752978AbZKPWHG (ORCPT ); Mon, 16 Nov 2009 17:07:06 -0500 Received: from hera.kernel.org ([140.211.167.34]:49489 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753991AbZKPWHE (ORCPT ); Mon, 16 Nov 2009 17:07:04 -0500 Date: Mon, 16 Nov 2009 22:06:41 GMT From: "tip-bot for H. Peter Anvin" Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, kees.cook@canonical.com, tglx@linutronix.de Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, kees.cook@canonical.com, tglx@linutronix.de In-Reply-To: <1258154897-6770-2-git-send-email-hpa@zytor.com> References: <1258154897-6770-2-git-send-email-hpa@zytor.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86-32: Use symbolic constants, safer CPUID when enabling EFER.NX Message-ID: Git-Commit-ID: 8a50e5135af0c243e117e94e27feb8d149c879b4 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 8a50e5135af0c243e117e94e27feb8d149c879b4 Gitweb: http://git.kernel.org/tip/8a50e5135af0c243e117e94e27feb8d149c879b4 Author: H. Peter Anvin AuthorDate: Fri, 13 Nov 2009 15:28:13 -0800 Committer: H. Peter Anvin CommitDate: Mon, 16 Nov 2009 13:44:56 -0800 x86-32: Use symbolic constants, safer CPUID when enabling EFER.NX Use symbolic constants rather than hard-coded values when setting EFER.NX in head_32.S, and do a more rigorous test for the validity of the response when probing for the extended CPUID range. Signed-off-by: H. Peter Anvin LKML-Reference: <1258154897-6770-2-git-send-email-hpa@zytor.com> Acked-by: Kees Cook --- arch/x86/kernel/head_32.S | 18 +++++++++++------- 1 files changed, 11 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 050c278..7fd318b 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -18,6 +18,8 @@ #include #include #include +#include +#include #include /* Physical address */ @@ -297,25 +299,27 @@ ENTRY(startup_32_smp) orl %edx,%eax movl %eax,%cr4 - btl $5, %eax # check if PAE is enabled - jnc 6f + testb $X86_CR4_PAE, %al # check if PAE is enabled + jz 6f /* Check if extended functions are implemented */ movl $0x80000000, %eax cpuid - cmpl $0x80000000, %eax - jbe 6f + /* Value must be in the range 0x80000001 to 0x8000ffff */ + subl $0x80000001, %eax + cmpl $(0x8000ffff-0x80000001), %eax + ja 6f mov $0x80000001, %eax cpuid /* Execute Disable bit supported? */ - btl $20, %edx + btl $(X86_FEATURE_NX & 31), %edx jnc 6f /* Setup EFER (Extended Feature Enable Register) */ - movl $0xc0000080, %ecx + movl $MSR_EFER, %ecx rdmsr - btsl $11, %eax + btsl $_EFER_NX, %eax /* Make changes effective */ wrmsr