Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757596AbYGNQeY (ORCPT ); Mon, 14 Jul 2008 12:34:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753763AbYGNQeP (ORCPT ); Mon, 14 Jul 2008 12:34:15 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:35905 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751153AbYGNQeO (ORCPT ); Mon, 14 Jul 2008 12:34:14 -0400 Date: Mon, 14 Jul 2008 18:34:02 +0200 From: Ingo Molnar To: Linus Torvalds Cc: Avi Kivity , Linux Kernel Mailing List , Andrew Morton Subject: Re: [git pull] core, x86: make LIST_POISON less deadly Message-ID: <20080714163402.GB21068@elte.hu> References: <20080714144828.GA22666@elte.hu> <20080714151247.GA27145@elte.hu> <487B7A10.9050104@qumranet.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1448 Lines: 38 * Linus Torvalds wrote: > On Mon, 14 Jul 2008, Avi Kivity wrote: > > > > We could add a printk to the #GP handler that alerts the reader that a > > poisoned list is suspected, if we find the address pattern in one of the > > registers. > > I wouldn't worry too much - it's going to be pretty visible anyway. > > The only thing I _would_ worry about is the AMD prefetch bug - some AMD > cores raise a spurious page fault for prefetch instructions, and we ignore > it. > > I _think_ that bug is a pure TLB issue and would never trigger for an > address that doesn't do page fault handling at all because it gets caught > in the "is the address valid" code, but it does make me go "Hmm". > > See > > http://lkml.org/lkml/2003/9/10/397 > > from Rich Brunner. The AMD errata listing does say just page fault, > and does talk about speculative TLB reloads, so I think we're all > good. one of my testboxes has this erratum and i saw related bugs in the past during stress-tests so it will show up if the non-canonical address causes any problems. So i think 0xdead000000000000 will be fine, and even if it isnt, we'll catch any problems fast enough. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/