Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753644AbbBKUQB (ORCPT ); Wed, 11 Feb 2015 15:16:01 -0500 Received: from mail-pa0-f50.google.com ([209.85.220.50]:49897 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752959AbbBKUQA (ORCPT ); Wed, 11 Feb 2015 15:16:00 -0500 Message-ID: <54DBB87C.5060901@amacapital.net> Date: Wed, 11 Feb 2015 12:15:56 -0800 From: Andy Lutomirski User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: "H.J. Lu" , Rich Felker CC: Catalin Marinas , Andrew Pinski , "linux-arm-kernel@lists.infradead.org" , LKML , Andrew Pinski , musl@lists.openwall.com, GNU C Library Subject: Re: [PATCHv3 00/24] ILP32 support in ARM64 References: <20141002155217.GH32147@e104818-lin.cambridge.arm.com> <20150210181302.GA23886@brightrain.aerifal.cx> <20150211190252.GB23507@brightrain.aerifal.cx> <20150211192558.GE23507@brightrain.aerifal.cx> <20150211194741.GI23507@brightrain.aerifal.cx> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1727 Lines: 35 On 02/11/2015 11:57 AM, H.J. Lu wrote: >>>> trivially satisfied if you consider x32 and x86_64 separate >>>> compilation environments, but it's not related to the core issue: that >>>> the definition of timespec violates core (not obscure) requirements of >>>> both POSIX and C11. At the time you were probably unaware of the C11 >>>> requirement. Note that it's a LOT harder to effect change in the C >>>> standard, so even if the Austin Group would be amenable to changing >>>> the requirement for timespec to allow something like nseconds_t, >>>> getting WG14 to make this change to work around a Linux/glibc mistake >>>> does not sound practical. >>> >>> That is very unfortunate. I consider it is too late for x32 to change. >> >> Why? It's hardly an incompatible ABI change, as long as the >> kernel/libc fills the upper bits (for old programs that read them >> based on the old headers) when structs are read from the kernel to the >> application, and ignores the upper bits (potentially set or left >> uninitialized by the application) when strings are passed from >> userspace to the kernel. Newly built apps using the struct definition >> with 32-bit tv_nsec would need new libc to ensure that the high bits >> aren't interpreted, but this could be handled by symbol versioning. >> > > We have considered this option. But since kernel wouldn't change > tv_nsec/tv_usec handling just for x32, it wasn't selected. > Did anyone *ask* the kernel people (e.g. hpa)? --Andy -- 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/