From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756172Ab0LHBOA (ORCPT ); Tue, 7 Dec 2010 20:14:00 -0500 Received: from kroah.org ([198.145.64.141]:33744 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932740Ab0LHBDe (ORCPT ); Tue, 7 Dec 2010 20:03:34 -0500 X-Mailbox-Line: From gregkh@clark.site Tue Dec 7 16:57:45 2010 Message-Id: <20101208005745.490732675@clark.site> User-Agent: quilt/0.48-11.2 Date: Tue, 07 Dec 2010 17:00:18 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Catalin Marinas , Will Deacon , Russell King Subject: [241/289] ARM: 6489/1: thumb2: fix incorrect optimisation in usracc In-Reply-To: <20101208005821.GA2922@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.36-stable review patch. If anyone has any objections, please let us know. ------------------ From: Will Deacon commit 1142b71d85894dcff1466dd6c871ea3c89e0352c upstream. Commit 8b592783 added a Thumb-2 variant of usracc which, when it is called with \rept=2, calls usraccoff once with an offset of 0 and secondly with a hard-coded offset of 4 in order to avoid incrementing the pointer again. If \inc != 4 then we will store the data to the wrong offset from \ptr. Luckily, the only caller that passes \rept=2 to this function is __clear_user so we haven't been actively corrupting user data. This patch fixes usracc to pass \inc instead of #4 to usraccoff when it is called a second time. Reported-by: Tony Thompson Acked-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/include/asm/assembler.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -215,7 +215,7 @@ @ Slightly optimised to avoid incrementing the pointer twice usraccoff \instr, \reg, \ptr, \inc, 0, \cond, \abort .if \rept == 2 - usraccoff \instr, \reg, \ptr, \inc, 4, \cond, \abort + usraccoff \instr, \reg, \ptr, \inc, \inc, \cond, \abort .endif add\cond \ptr, #\rept * \inc