From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267815AbUHJXTL (ORCPT ); Tue, 10 Aug 2004 19:19:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267814AbUHJXTL (ORCPT ); Tue, 10 Aug 2004 19:19:11 -0400 Received: from holomorphy.com ([207.189.100.168]:14829 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S267815AbUHJXPO (ORCPT ); Tue, 10 Aug 2004 19:15:14 -0400 Date: Tue, 10 Aug 2004 16:15:07 -0700 From: William Lee Irwin III To: Robert Picco Cc: Jesse Barnes , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: 2.6.8-rc4-mm1 Message-ID: <20040810231507.GF11200@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Robert Picco , Jesse Barnes , Andrew Morton , linux-kernel@vger.kernel.org References: <20040810002110.4fd8de07.akpm@osdl.org> <200408100937.47451.jbarnes@engr.sgi.com> <20040810212033.GY11200@holomorphy.com> <41194EA5.80706@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41194EA5.80706@hp.com> User-Agent: Mutt/1.5.6+20040722i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 10, 2004 at 06:39:33PM -0400, Robert Picco wrote: > copy_thread expects a switch_stack below pt_regs on the stack. the > switch_stack would have the parent's bspstore value for computing how > much register backing store to copy into child. there isn't a > switch_stack and the resultant bspstore size computed is enormous > (depends on what there is on stack). i suspect printk has changed stack > and the code layout changed too. [...] > * For SMP idle threads, fork_by_hand() calls do_fork with > * NULL regs. > */ > - if (!regs) > + if (clone_flags & CLONE_IDLETASK) > return 0; > #endif It may not be immediately obvious, but since all the checks for CLONE_IDLETASK were ripped out in patches prior to this, respecting CLONE_IDLETASK anywhere means that userspace can create idle threads(!). So the alternative fixes I've been posting are very necessary. -- wli