Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760201AbXKAPSV (ORCPT ); Thu, 1 Nov 2007 11:18:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754625AbXKAPSO (ORCPT ); Thu, 1 Nov 2007 11:18:14 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:39373 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754571AbXKAPSN (ORCPT ); Thu, 1 Nov 2007 11:18:13 -0400 Date: Thu, 1 Nov 2007 16:17:53 +0100 From: Ingo Molnar To: Pavel Emelyanov Cc: Peter Zijlstra , Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Ulrich Drepper Subject: Re: [patch] PID namespace design bug, workaround Message-ID: <20071101151753.GA6181@elte.hu> References: <20071101144307.GA29566@elte.hu> <4729E7E4.8070208@openvz.org> <1193928977.27652.289.camel@twins> <4729EB88.6080408@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4729EB88.6080408@openvz.org> User-Agent: Mutt/1.5.16 (2007-06-09) 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=3.1.7-deb -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1510 Lines: 31 * Pavel Emelyanov wrote: > The "fix" I mention is just returning -EINVAL in case user orders > CLONE_NEWPIDS and compiling out all the namespace cloning code. This > is just a more elegant way to get rid of pid namespaces rather than > Ingo proposed. unfortunately i have to NACK that approach. We never allowed broken user-space visible APIs into the kernel like that because it just gives a vector for that breakage to become de-facto used and forced upon the core kernel. Even if they can be .config turned off. That's just a lame excuse that delays the fixing of it. We may mark features that have a good expectation to be fixed as CONFIG_EXPERIMENTAL, and we may mark drivers that nobody maintains anymore as CONFIG_BROKEN, but we dont introduce new core syscall features with CONFIG_BROKEN! We never did and i hope we never will. The _only_ way to force the fixing of such type of breakages is to not offer them _at all_. Really, you are proposing a major new extension to lots of important core Linux APIs so please try to solve this problem cleanly, it's really severe. Right now as things stand this containers sub-feature is "a little bit pregnant". This is one of the few cases where we really _must_ say no. 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/