From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH 08/10] Use __kernel_ulong_t in struct msqid64_ds Date: Fri, 18 May 2012 15:08:34 -0700 Message-ID: <4FB6C862.5060401@zytor.com> References: <1337292816-10839-1-git-send-email-hjl.tools@gmail.com> <201205182131.29353.arnd@arndb.de> <4FB6C1F7.1010307@zytor.com> <201205182158.59616.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:48114 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967321Ab2ERWIx (ORCPT ); Fri, 18 May 2012 18:08:53 -0400 In-Reply-To: <201205182158.59616.arnd@arndb.de> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Arnd Bergmann Cc: Linus Torvalds , David Daney , Ralf Baechle , "H.J. Lu" , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de On 05/18/2012 02:58 PM, Arnd Bergmann wrote: > > But why do you think it's wrong the way it is? I see the idea of putting > padding in varying places depending on the endianess as a failed experiment > and defining a structure that is always the same as the logical conclusion > from that, even if it's a bit silly to have any padding in it at all. > The *whole point* is to make the structure the same across modes, to make the compat layer's job easier. > Being consistent seems more important here than following the intent > of whoever came up with the concept of the ipc64 data structures > and was consequently ignored by most people after him. So you're saying because some architectures introduced a bug, we should *CONTINUE* to introduce the same bug?? WTF?? > If we really wanted the data structures to be compatible between 32 and > 64 bit mode, we'd have to use __u64 here but that would mean having to > change all bits of user code that already rely on the existing x86 > compatible layout. x86 is doing it right. Some bigendian architectures blindly copied what x86 was doing without thinking. That's a bug on their part, period. -hpa