From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751413AbaJAMmn (ORCPT ); Wed, 1 Oct 2014 08:42:43 -0400 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:40061 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751053AbaJAMmm (ORCPT ); Wed, 1 Oct 2014 08:42:42 -0400 Date: Wed, 1 Oct 2014 13:42:27 +0100 From: Catalin Marinas To: Arnd Bergmann Cc: "linux-arm-kernel@lists.infradead.org" , "pinskia@gmail.com" , Andrew Pinski , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 08/24] Allow a 32bit ABI to use the naming of the 64bit ABI syscalls to avoid confusion of not splitting the registers Message-ID: <20141001124226.GI12702@e104818-lin.cambridge.arm.com> References: <1409779158-30963-1-git-send-email-apinski@cavium.com> <1409779158-30963-9-git-send-email-apinski@cavium.com> <3318813.yqP9pCQtAB@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3318813.yqP9pCQtAB@wuerfel> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 04, 2014 at 11:11:04AM +0100, Arnd Bergmann wrote: > On Wednesday 03 September 2014 14:19:02 Andrew Pinski wrote: > > + * For 32bit abis where 64bit can be passed via one > > + * register, use the same naming as the 64bit ones > > + * as they will only have a 64 bit off_t. > > */ > > -#if __BITS_PER_LONG == 64 && !defined(__SYSCALL_COMPAT) > > +#if (__BITS_PER_LONG == 64 && !defined(__SYSCALL_COMPAT)) || \ > > + defined(__ARCH_WANT_64BIT_SYSCALLS) > > I'm not sure if __ARCH_WANT_64BIT_SYSCALLS is the best name for > this, since it's really only about off_t. It took me a while > to understand what you are doing here. I'm not sure I fully get it yet. So with this change, we avoid using syscall numbers like __NR_ftruncate64 in favour of __NR_ftruncate. Why? (maybe there's a valid reason, just not getting it). Either way, ILP32 would still end up calling sys_ftruncate64() (rather than the native sys_ftruncate()). -- Catalin