From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755476AbcBZWKS (ORCPT ); Fri, 26 Feb 2016 17:10:18 -0500 Received: from ozlabs.org ([103.22.144.67]:51639 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752825AbcBZWKR (ORCPT ); Fri, 26 Feb 2016 17:10:17 -0500 Date: Sat, 27 Feb 2016 09:10:13 +1100 From: Stephen Rothwell To: "H. Peter Anvin" Cc: Dave Hansen , linux-kernel@vger.kernel.org, dave.hansen@linux.intel.com, akpm@linux-foundation.org, tglx@linutronix.de, mingo@elte.hu, peterz@infradead.org, linux-next@vger.kernel.org, deller@gmx.de Subject: Re: [PATCH] x86, pkeys: fix siginfo ABI breakage from new field Message-ID: <20160227091013.6e0606d1@canb.auug.org.au> In-Reply-To: <6C5C3B9B-CAD6-4010-9A3E-AFFF7E13FAE3@zytor.com> References: <20160226173427.54A6949F@viggo.jf.intel.com> <6C5C3B9B-CAD6-4010-9A3E-AFFF7E13FAE3@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Fri, 26 Feb 2016 09:44:00 -0800 "H. Peter Anvin" wrote: > > > __u64 is okay, "unsigned long" is really messy in the presence of 32-on-64 bit ABIs... Yeah, but unfortunately, any 64 bit scalar type here will change the alignment of the enclosing unions on (some) 32 bit platforms and thus break the ABI. -- Cheers, Stephen Rothwell