Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754157Ab0FSFxX (ORCPT ); Sat, 19 Jun 2010 01:53:23 -0400 Received: from smtp.outflux.net ([198.145.64.163]:43287 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753192Ab0FSFxV (ORCPT ); Sat, 19 Jun 2010 01:53:21 -0400 Date: Fri, 18 Jun 2010 22:52:59 -0700 From: Kees Cook To: x86@kernel.org Cc: "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Alexander Potashev , Tim Abbott , Sam Ravnborg , Jan Beulich , Jeremy Fitzhardinge , linux-kernel@vger.kernel.org Subject: [PATCH 3/4] x86: call verify_cpu during 32bit CPU startup Message-ID: <20100619055259.GU24749@outflux.net> References: <20100619055010.GR24749@outflux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100619055010.GR24749@outflux.net> Organization: Canonical X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1579 Lines: 57 The XD_DISABLE-clearing side-effect needs to happen on 32bit CPU start-up as well. Signed-off-by: Kees Cook --- arch/x86/kernel/head_32.S | 6 ++++++ arch/x86/kernel/verify_cpu.S | 1 + 2 files changed, 7 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 37c3d4b..0dec923 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -309,6 +309,10 @@ ENTRY(startup_32_smp) subl $0x80000001, %eax cmpl $(0x8000ffff-0x80000001), %eax ja 6f + + /* Clear bogus XD_DISABLE bits */ + call verify_cpu + mov $0x80000001, %eax cpuid /* Execute Disable bit supported? */ @@ -604,6 +608,8 @@ ignore_int: #endif iret +#include "verify_cpu.S" + __REFDATA .align 4 ENTRY(initial_code) diff --git a/arch/x86/kernel/verify_cpu.S b/arch/x86/kernel/verify_cpu.S index d6a0be6..29a6357 100644 --- a/arch/x86/kernel/verify_cpu.S +++ b/arch/x86/kernel/verify_cpu.S @@ -19,6 +19,7 @@ * * arch/x86_64/boot/compressed/head_64.S: Boot cpu verification * arch/x86_64/kernel/trampoline_64.S: secondary processor verfication + * arch/x86_64/kernel/head_32.S: processor startup * * verify_cpu, returns the status of longmode and SSE in register %eax. * 0: Success 1: Failure -- 1.7.1 -- Kees Cook Ubuntu Security Team -- 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/