From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262714AbTLCXgL (ORCPT ); Wed, 3 Dec 2003 18:36:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262738AbTLCXgL (ORCPT ); Wed, 3 Dec 2003 18:36:11 -0500 Received: from bolt.sonic.net ([208.201.242.18]:27367 "EHLO bolt.sonic.net") by vger.kernel.org with ESMTP id S262714AbTLCXgC (ORCPT ); Wed, 3 Dec 2003 18:36:02 -0500 Date: Wed, 3 Dec 2003 15:36:01 -0800 From: David Hinds To: J?rn Engel , linux-kernel@vger.kernel.org Subject: Re: Worst recursion in the kernel Message-ID: <20031203153601.A23640@sonic.net> References: <20031203143122.GA6470@wohnheim.fh-wedel.de> <20031203100709.B6625@sonic.net> <20031203190440.GA15857@wohnheim.fh-wedel.de> <20031203225743.A25889@flint.arm.linux.org.uk> <20031203230832.GD29119@mis-mike-wstn.matchmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031203230832.GD29119@mis-mike-wstn.matchmail.com> User-Agent: Mutt/1.3.22.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 03, 2003 at 03:08:32PM -0800, Mike Fedyk wrote: > On Wed, Dec 03, 2003 at 10:57:43PM +0000, Russell King wrote: > > Yes, but the condition of the /data/ is such that it will not recurse. > > > > A pure "can this function call that function" analysis ignoring the > > state of the data will say this will infinitely recuse. Include > > the data, and you'll find it has a very definite recursion limit. > > Is the data verified? Russell is using "data" loosely. Basically the logic goes like this: read_cis_mem(): if sys_start is NULL then call validate_mem() validate_mem(): set sys_start call stuff that calls read_cis_mem() so the functions do not require consistency of any external program data to avoid recursion. -- Dave