Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754465Ab1CUUl1 (ORCPT ); Mon, 21 Mar 2011 16:41:27 -0400 Received: from mail-vw0-f46.google.com ([209.85.212.46]:59045 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754394Ab1CUUlZ (ORCPT ); Mon, 21 Mar 2011 16:41:25 -0400 Date: Mon, 21 Mar 2011 16:41:19 -0400 (EDT) From: Nicolas Pitre X-X-Sender: nico@xanadu.home To: Po-Yu Chuang cc: Ashwin Chaugule , Russell King - ARM Linux , Po-Yu Chuang , tony@atomide.com, lkml , joe@perches.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2] arm: cmpxchg syscall should data abort if page not write In-Reply-To: Message-ID: References: <1300098516-1601-1-git-send-email-ratbert.chuang@gmail.com> <1300169637-1628-1-git-send-email-ratbert.chuang@gmail.com> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="8323328-1230036926-1300740081=:11889" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1448 Lines: 34 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-1230036926-1300740081=:11889 Content-Type: TEXT/PLAIN; charset=UTF-8 Content-Transfer-Encoding: 8BIT On Fri, 18 Mar 2011, Po-Yu Chuang wrote: > On Fri, Mar 18, 2011 at 1:57 AM, Nicolas Pitre wrote: > > Nope.  The code being fixed here was suptly broken so it needs fixing. > > However this code is almost never used, if at all, as it is a fall-back > > solution for when all the better alternatives are not available for some > > reasons (and I'm still wondering what those reasons are for Po-Yu Chuang > > to actually use that code).  In practice this bug should have affected > > no one. > > We met this problem while porting an v5 SMP processor because kernel > selects NEEDS_SYSCALL_FOR_CMPXCHG by default if CPU_32v5. > > After we added our own implementation of __kuser_cmpxchg, this code > is not needed anymore. But since this is actually a bug, it is still a good > idea to submit a patch. :-) Yes. Please send to RMK's patch system with my ACK. Nicolas --8323328-1230036926-1300740081=:11889-- -- 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/