From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753082Ab0CXU7u (ORCPT ); Wed, 24 Mar 2010 16:59:50 -0400 Received: from tex.lwn.net ([70.33.254.29]:50673 "EHLO vena.lwn.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751604Ab0CXU7t (ORCPT ); Wed, 24 Mar 2010 16:59:49 -0400 Date: Wed, 24 Mar 2010 14:59:46 -0600 From: Jonathan Corbet To: Andrew Morton Cc: Mel Gorman , Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , Minchan Kim , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 07/11] Memory compaction core Message-ID: <20100324145946.372f3f31@bike.lwn.net> In-Reply-To: <20100324133347.9b4b2789.akpm@linux-foundation.org> References: <1269347146-7461-1-git-send-email-mel@csn.ul.ie> <1269347146-7461-8-git-send-email-mel@csn.ul.ie> <20100324133347.9b4b2789.akpm@linux-foundation.org> Organization: LWN.net X-Mailer: Claws Mail 3.7.5 (GTK+ 2.19.7; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 24 Mar 2010 13:33:47 -0700 Andrew Morton wrote: > > + VM_BUG_ON(cc == NULL); > > It's a bit strange to test this when we're about to oops anyway. The > oops will tell us the same thing. ...except that we've seen a fair number of null pointer dereference exploits that have told us something altogether different. Are we *sure* we don't want to test for null pointers...? jon