From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263340AbUE3MeR (ORCPT ); Sun, 30 May 2004 08:34:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263429AbUE3MeR (ORCPT ); Sun, 30 May 2004 08:34:17 -0400 Received: from mail1.kontent.de ([81.88.34.36]:17870 "EHLO Mail1.KONTENT.De") by vger.kernel.org with ESMTP id S263340AbUE3MeQ (ORCPT ); Sun, 30 May 2004 08:34:16 -0400 From: Oliver Neukum To: Sau Dan Lee Subject: Re: keyboard problem with 2.6.6 Date: Sun, 30 May 2004 14:32:45 +0200 User-Agent: KMail/1.6.2 Cc: Vojtech Pavlik , Giuseppe Bilotta , linux-kernel@vger.kernel.org, Tuukka Toivonen References: <200405301401.20196.oliver@neukum.org> In-Reply-To: MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <200405301432.45736.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Am Sonntag, 30. Mai 2004 14:22 schrieb Sau Dan Lee: > >>>>> "Oliver" == Oliver Neukum writes: > > >> Where it is now possible to move it out of kernel space WITHOUT > >> performance problems, why not move it out? > > Oliver> Two reasons: security and robustness. > > Oliver> 1. sysreq must work, always work. Ideally you even do the > Oliver> dump in hard irq. USB has been modified to support this. > > It doesn't always work. Try to compile 'i8042' and 'atkbd' as > modules. rmmod one of them, and voila: SysRq doesn't work anymore. Yes. Remove the driver for your root fs and, lo, the kernel will panic. You must not confuse kernel and user space. The notion that drivers can be compiled into modules is not exactly new. In which context they run is the all important question. Oliver