Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752399Ab0KWV0u (ORCPT ); Tue, 23 Nov 2010 16:26:50 -0500 Received: from relais.videotron.ca ([24.201.245.36]:62029 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750943Ab0KWV0t (ORCPT ); Tue, 23 Nov 2010 16:26:49 -0500 MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: TEXT/PLAIN; charset=US-ASCII Date: Tue, 23 Nov 2010 16:26:47 -0500 (EST) From: Nicolas Pitre X-X-Sender: nico@xanadu.home To: James Jones Cc: Russell King , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ARM: Fix find_next_zero_bit and related assembly In-reply-to: <1289524615-22484-1-git-send-email-jajones@nvidia.com> Message-id: References: <1289524615-22484-1-git-send-email-jajones@nvidia.com> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1858 Lines: 61 On Thu, 11 Nov 2010, James Jones wrote: > 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. > > Signed-off-by: James Jones > Tested-by: Stephen Warren Reviewed-by: Nicolas Pitre Please send to RMK's patch system. > --- > 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 > > -- > 1.7.1 > > -- > 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/ > -- 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/