From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755372Ab1HaU7k (ORCPT ); Wed, 31 Aug 2011 16:59:40 -0400 Received: from terminus.zytor.com ([198.137.202.10]:58037 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752429Ab1HaU7j (ORCPT ); Wed, 31 Aug 2011 16:59:39 -0400 Message-ID: <4E5EA068.9070206@zytor.com> Date: Wed, 31 Aug 2011 13:58:16 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:6.0) Gecko/20110816 Thunderbird/6.0 MIME-Version: 1.0 To: Arnd Bergmann CC: Alan Cox , Linus Torvalds , Christoph Hellwig , LKML , "H.J. Lu" , Ingo Molnar , Thomas Gleixner , Richard Kuo , Mark Salter , Jonas Bonn , Tobias Klauser Subject: Re: RFD: x32 ABI system call numbers References: <4E582577.2060805@zytor.com> <20110831205439.1a0c94da@lxorguk.ukuu.org.uk> <4E5E9347.4010503@zytor.com> <2902501.mMiynrre7t@wuerfel> In-Reply-To: <2902501.mMiynrre7t@wuerfel> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/31/2011 01:55 PM, Arnd Bergmann wrote: > > But isn't this mostly a glibc thing then? The definition of time_t that > is used by applications comes from bits/typesizes.h, not from the > kernel's linux/types.h. If we use 64 bit time_t values internally > in the kernel and truncate them to 32 bits on the user interface, > there is no visible difference between signed and unsigned values > for data passed from kernel to user when it's interpreted as > signed int anyway. > > For the rarer case of user space passing a 32 bit time_t into the > kernel (e.g. utimensat), there is of course a difference. > Yes, exactly. It should be done in a coordinated fashion. -hpa