From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932527AbYETPOd (ORCPT ); Tue, 20 May 2008 11:14:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933030AbYETPN4 (ORCPT ); Tue, 20 May 2008 11:13:56 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:51204 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932977AbYETPNz (ORCPT ); Tue, 20 May 2008 11:13:55 -0400 Date: Tue, 20 May 2008 08:12:41 -0700 (PDT) From: Linus Torvalds To: Alexey Dobriyan cc: Dave Jones , Arjan van de Ven , Matthew Wilcox , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Make In-Reply-To: Message-ID: References: <20080502182745.GL14976@parisc-linux.org> <20080501133209.2c04dad0@infradead.org> <20080502184922.GM14976@parisc-linux.org> <20080520032448.GA19348@redhat.com> <20080520071458.707d6e90@infradead.org> <20080520142727.GC4843@redhat.com> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 20 May 2008, Alexey Dobriyan wrote: > > Why list_head corruptions are special? It's not that list corruptions are special, but: - *any* corruption is very interesting, and the earlier we find it the better - we have a lot of lists in the kernel, so testing pointers is actually likely to find stuff. - and lists are something we can *test* for corruption That third one is important. Most random pointers we can't sanely test because they don't have trivial and important patterns. The second one is relevant too: some of the pointers that we *could* test (struct task has a pointer to the thread struct and back, and we could test that) are just not common enough to be worth testing. And other concepts don't have any nice centralized routines for adding the test. So no, lists aren't "special" in any inherent way, they are just special in these kinds of "incidentally, a lot of random data structure corruption has traditionally shown up in lists, because there are so many of them". Linus