From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759116AbXKHE72 (ORCPT ); Wed, 7 Nov 2007 23:59:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753067AbXKHE7U (ORCPT ); Wed, 7 Nov 2007 23:59:20 -0500 Received: from ozlabs.org ([203.10.76.45]:45498 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752495AbXKHE7U (ORCPT ); Wed, 7 Nov 2007 23:59:20 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18226.38816.486372.52353@cargo.ozlabs.ibm.com> Date: Thu, 8 Nov 2007 15:59:12 +1100 From: Paul Mackerras To: Andrew Morton Cc: lkml@davidb.org, linux-kernel@vger.kernel.org, drepper@redhat.com, mtk-manpages@gmx.net Subject: Re: compat_sys_times() bogus until jiffies >= 0. In-Reply-To: <20071107190714.9c404e28.akpm@linux-foundation.org> References: <20071107224722.GA20204@old.davidb.org> <20071107152833.6f302c2a.akpm@linux-foundation.org> <20071107161853.044b6e8f.akpm@linux-foundation.org> <18226.27701.782268.375231@cargo.ozlabs.ibm.com> <20071107190714.9c404e28.akpm@linux-foundation.org> X-Mailer: VM 7.19 under Emacs 21.4.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton writes: > "the latter" is what my protopatch does isn't it? It wraps at 0x7fffffff. > It appears that glibc treats all of 0x80000000-0xffffffff as an error. Not on powerpc. On powerpc the error indication is carried separately in a condition register bit. So a force_successful_syscall_return() call will make glibc automatically do the right thing without any glibc changes on powerpc. Wrapping at 0x7fffffff will cause programs to see large negative deltas between successive calls when the wrap occurs. I can see that giving userspace fits. :) Paul.