From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751820AbXCTQzR (ORCPT ); Tue, 20 Mar 2007 12:55:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751821AbXCTQzQ (ORCPT ); Tue, 20 Mar 2007 12:55:16 -0400 Received: from smtp.osdl.org ([65.172.181.24]:47539 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751820AbXCTQzO (ORCPT ); Tue, 20 Mar 2007 12:55:14 -0400 Date: Tue, 20 Mar 2007 09:52:42 -0700 (PDT) From: Linus Torvalds To: Andi Kleen cc: "Eric W. Biederman" , David Miller , virtualization@lists.linux-foundation.org, jbeulich@novell.com, jeremy@goop.org, xen-devel@lists.xensource.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, chrisw@sous-sol.org, virtualization@lists.osdl.org, anthony@codemonkey.ws, akpm@linux-foundation.org, mingo@elte.hu Subject: Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable In-Reply-To: <20070320174159.GA4286@bingen.suse.de> Message-ID: References: <20070319.120854.30182994.davem@davemloft.net> <20070319.204712.118947830.davem@davemloft.net> <200703201428.50564.ak@suse.de> <20070320174159.GA4286@bingen.suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 20 Mar 2007, Andi Kleen wrote: > > No, me and Jan fixed all reported bugs as far as I know. No you did not. You didn't fix the ones I reported. Which is why it got removed, and will not get added back until there is another maintainer. The ones I reported were all about trusting the stack contents implicitly, and assuming that the unwind info was there and valid. Using things like "__get_user()" didn't fix it, because if a WARN_ON() happened while we held the mm semaphore and the unwind info was bogus, it would take a page-fault and deadlock. Those kinds of things are not acceptable for debugging output. If I cannot use WARN_ON() because I hold the MM lock and I'm afraid there might be kernel corruption, then something is *wrong*! And I told you guys this. Over *months*. And you ignored me. You told me everything was fine. Each time, somebody else ended up reporting a hang where the unwinder was at fault. And since I couldn't trust the maintainers to fix it, removing the broken feature that only caused more problems than it fixed was the only option. And you clearly *still* haven't accepted the fact that the code was buggy. Does anybody wonder why I wouldn't merge it back? Linus