From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965655AbXCBVVA (ORCPT ); Fri, 2 Mar 2007 16:21:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965656AbXCBVVA (ORCPT ); Fri, 2 Mar 2007 16:21:00 -0500 Received: from ruby.spiritone.com ([216.99.193.130]:55232 "EHLO ruby.spiritone.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965655AbXCBVU7 (ORCPT ); Fri, 2 Mar 2007 16:20:59 -0500 Message-ID: <45E894FA.2040103@BitWagon.com> Date: Fri, 02 Mar 2007 13:19:54 -0800 From: John Reiser Organization: - User-Agent: Mozilla Thunderbird 1.0.8-1.1.fc4 (X11/20060501) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Oleg Nesterov CC: Paul Mundt , Andi Kleen , Ingo Molnar , Arjan van de Ven , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: + fully-honor-vdso_enabled.patch added to -mm tree References: <20070301175207.GA849@tv-sign.ru> <20070302034800.GA12530@linux-sh.org> <20070302193219.GA87@tv-sign.ru> In-Reply-To: <20070302193219.GA87@tv-sign.ru> X-Enigmail-Version: 0.92.0.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Oleg Nesterov wrote: > Still, I don't understand why we don't pass NEW_AUX_ENT(AT_SYSINFO) when > vdso_enabled == 0. We don't need linux-gate.so to use __kernel_vsyscall, > we have FIX_VDSO. In that case we should s/PAGE_KERNEL_RO/PAGE_READONLY/ > of course. I guess the reason is some magic in glibc. In the past there were problems where user code could not single-step (or even read the code of) such system calls. Can these two operations be performed today with what you propose, particularly if FIX_VDSO is near 0xfffff000 ? -- John Reiser, jreiser@BitWagon.com