From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933551Ab1DNRvF (ORCPT ); Thu, 14 Apr 2011 13:51:05 -0400 Received: from mail.windriver.com ([147.11.1.11]:38562 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933450Ab1DNRrW (ORCPT ); Thu, 14 Apr 2011 13:47:22 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, James Jones , Russell King , Paul Gortmaker Subject: [34-longterm 097/209] ARM: 6482/2: Fix find_next_zero_bit and related assembly Date: Thu, 14 Apr 2011 13:42:07 -0400 Message-Id: <1302803039-9400-98-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1302803039-9400-1-git-send-email-paul.gortmaker@windriver.com> References: <1302803039-9400-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: James Jones ===================================================================== | This is a commit scheduled for the next v2.6.34 longterm release. | | If you see a problem with using this for longterm, please comment.| ===================================================================== commit 0e91ec0c06d2cd15071a6021c94840a50e6671aa upstream. The find_next_bit, find_first_bit, find_next_zero_bit and find_first_zero_bit functions were not properly clamping to the maxbit argument at the bit level. They were instead only checking maxbit at the byte level. To fix this, add a compare and a conditional move instruction to the end of the common bit-within-the- byte code used by all the functions and be sure not to clobber the maxbit argument before it is used. Reviewed-by: Nicolas Pitre Tested-by: Stephen Warren Signed-off-by: James Jones Signed-off-by: Russell King Signed-off-by: Paul Gortmaker --- arch/arm/lib/findbit.S | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S index 1e4cbd4..64f6bc1 100644 --- a/arch/arm/lib/findbit.S +++ b/arch/arm/lib/findbit.S @@ -174,8 +174,8 @@ ENDPROC(_find_next_bit_be) */ .L_found: #if __LINUX_ARM_ARCH__ >= 5 - rsb r1, r3, #0 - and r3, r3, r1 + rsb r0, r3, #0 + and r3, r3, r0 clz r3, r3 rsb r3, r3, #31 add r0, r2, r3 @@ -190,5 +190,7 @@ ENDPROC(_find_next_bit_be) addeq r2, r2, #1 mov r0, r2 #endif + cmp r1, r0 @ Clamp to maxbit + movlo r0, r1 mov pc, lr -- 1.7.4.4