From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933174AbbEPHVK (ORCPT ); Sat, 16 May 2015 03:21:10 -0400 Received: from www.linutronix.de ([62.245.132.108]:44164 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753552AbbEPHVI (ORCPT ); Sat, 16 May 2015 03:21:08 -0400 Date: Sat, 16 May 2015 09:21:14 +0200 (CEST) From: Thomas Gleixner To: Arnd Bergmann cc: y2038@lists.linaro.org, baolin.wang@linaro.org, albert.aribaud@3adev.fr, john.stultz@linaro.org, bamvor.zhangjian@linaro.org, ruchandani.tina@gmail.com, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, libc-alpha@sourceware.org Subject: Re: [PATCH 17/19] y2038: use __kernel_timespec in sys_futex In-Reply-To: Message-ID: References: <1430929826-318934-1-git-send-email-arnd@arndb.de> <1430929826-318934-18-git-send-email-arnd@arndb.de> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 16 May 2015, Thomas Gleixner wrote: > On Wed, 6 May 2015, Arnd Bergmann wrote: > > > Conversion for sys_futex is particularly easy, we can use the unmodified > > compat_sys_futex on 32-bit systems to provide compatibility for 32-bit > > time_t, and change sys_futex to pass a __kernel_timespec, which matches > > what future libc implementations will use as their struct timespec. > > Unless I'm missing something I doubt that you get away that easy. It > works on 32bit, but not on 64 bit with 32bit app support: > > Native 64bit: sys_futex() > 32bit timespec32: compat_sys_futex() > 32bit timespec64: ????? > > You cannot map that to sys_futex() because the pointer size differs. Ignore that. You are right. Review induced brainmelt.... tglx