Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756923Ab3IMP7E (ORCPT ); Fri, 13 Sep 2013 11:59:04 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:54660 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755032Ab3IMP7B (ORCPT ); Fri, 13 Sep 2013 11:59:01 -0400 Date: Fri, 13 Sep 2013 16:58:36 +0100 From: Russell King To: Josh Boyer Cc: Geert Uytterhoeven , Chris Mason , Mark Fasheh , Linus Torvalds , linux-btrfs , "Linux-Kernel@Vger. Kernel. Org" , Linux-Arch Subject: Re: [GIT PULL] Btrfs Message-ID: <20130913155835.GA9697@flint.arm.linux.org.uk> Mail-Followup-To: Josh Boyer , Geert Uytterhoeven , Chris Mason , Mark Fasheh , Linus Torvalds , linux-btrfs , "Linux-Kernel@Vger. Kernel. Org" , Linux-Arch References: <20130912153629.16487.88969@localhost.localdomain> <20130913121529.GA1437@flint.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2110 Lines: 47 On Fri, Sep 13, 2013 at 11:38:15AM -0400, Josh Boyer wrote: > On Fri, Sep 13, 2013 at 11:06 AM, Josh Boyer wrote: > > On Fri, Sep 13, 2013 at 8:15 AM, Russell King wrote: > >> On Fri, Sep 13, 2013 at 07:53:21AM -0400, Josh Boyer wrote: > >>> I'm not an ARM expert, so I don't know if ARM should use the > >>> asm-generic implementations, or just use __get_user/__put_user in all > >>> cases. I've CC'd rmk. > >> > >> Why do we have uaccess-unaligned.h ? Normally, these kinds of things > >> are spawned by architectures which have problems with unaligned accesses, > >> ARM being one of them, but afaik we've never need this. > >> > >> With the kernel-side trapping of unaligned accesses on older hardware, > >> we've always dealt with the normal accessor faulting. > >> > >> From what I can tell in the git history, these unaligned put_user and > >> get_user have existed all the way back to the dawn of git use. > >> > >> Can someone enlighten me why we have them? > > I somehow fail at email and dropped Russell from CC on accident. Sigh. You're not the first to do that recently. I'm beginning to think it's something someone has written into email clients to make them do in order to piss me off. I mean, it's _hard_ to do - you have to manually edit the recipients list to just drop one person. > > So while that gets sorted out, would it be safe to just do as Geert > > did on m68k and put: > > > > #define __put_user_unaligned(x, ptr) __put_user((x), (ptr)) > > > > in arch/arm/include/asm/uaccess.h, and let the normal accessors and > > kernel-side trapping deal with things? I'm thinking that's a local > > fix until something gets sorted upstream, but I don't want to do it if > > it's going to break things. Yep, that should work just fine. -- Russell King ARM architecture Linux Kernel maintainer -- 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/