From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762940AbZBDTAm (ORCPT ); Wed, 4 Feb 2009 14:00:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761407AbZBDStd (ORCPT ); Wed, 4 Feb 2009 13:49:33 -0500 Received: from kroah.org ([198.145.64.141]:32806 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1761380AbZBDStY (ORCPT ); Wed, 4 Feb 2009 13:49:24 -0500 Date: Wed, 4 Feb 2009 10:46:36 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Zhao Yakui , Venki Pallipadi , Len Brown , Thomas Renninger Subject: [patch 24/41] ACPI: Avoid array address overflow when _CST MWAIT hint bits are set Message-ID: <20090204184636.GY25246@kroah.com> References: <20090204184029.881610776@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="acpi-avoid-array-address-overflow-when-_cst-mwait-hint-bits-are-set.patch" In-Reply-To: <20090204184539.GA25246@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Zhao Yakui commit 13b40a1a065824d2d4e55c8b48ea9f3f9d162929 upstream. The Cx Register address obtained from the _CST object is used as the MWAIT hints if the register type is FFixedHW. And it is used to check whether the Cx type is supported or not. On some boxes the following Cx state package is obtained from _CST object: >{ ResourceTemplate () { Register (FFixedHW, 0x01, // Bit Width 0x02, // Bit Offset 0x0000000000889759, // Address 0x03, // Access Size ) }, 0x03, 0xF5, 0x015E } In such case we should use the bit[7:4] of Cx address to check whether the Cx type is supported or not. mask the MWAIT hint to avoid array address overflow Signed-off-by: Zhao Yakui Acked-by:Venki Pallipadi Signed-off-by: Len Brown Cc: Thomas Renninger --- arch/x86/kernel/acpi/cstate.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -56,6 +56,7 @@ static struct cstate_entry *cpu_cstate_e static short mwait_supported[ACPI_PROCESSOR_MAX_POWER]; #define MWAIT_SUBSTATE_MASK (0xf) +#define MWAIT_CSTATE_MASK (0xf) #define MWAIT_SUBSTATE_SIZE (4) #define CPUID_MWAIT_LEAF (5) @@ -98,7 +99,8 @@ int acpi_processor_ffh_cstate_probe(unsi cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx); /* Check whether this particular cx_type (in CST) is supported or not */ - cstate_type = (cx->address >> MWAIT_SUBSTATE_SIZE) + 1; + cstate_type = ((cx->address >> MWAIT_SUBSTATE_SIZE) & + MWAIT_CSTATE_MASK) + 1; edx_part = edx >> (cstate_type * MWAIT_SUBSTATE_SIZE); num_cstate_subtype = edx_part & MWAIT_SUBSTATE_MASK;