From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751451AbXDHQU4 (ORCPT ); Sun, 8 Apr 2007 12:20:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751443AbXDHQU4 (ORCPT ); Sun, 8 Apr 2007 12:20:56 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:48584 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750717AbXDHQUz (ORCPT ); Sun, 8 Apr 2007 12:20:55 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Oleg Nesterov Cc: Andrew Morton , Davide Libenzi , Ingo Molnar , Linus Torvalds , Robin Holt , Roland McGrath , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [RFC, PATCH 1/3] introduce SYS_CLONE_MASK References: <20070408155337.GA126@tv-sign.ru> Date: Sun, 08 Apr 2007 10:19:48 -0600 In-Reply-To: <20070408155337.GA126@tv-sign.ru> (Oleg Nesterov's message of "Sun, 8 Apr 2007 19:53:37 +0400") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) 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 Oleg Nesterov writes: > For review only. > > To implement for-in-kerenl-use-only CLONE_ flags, we need to filter out them > in sys_clone(). Nack The current clone_flags field is for user space consumption and we have proposed users for all or almost all of the remaining bits. If we are going to have kernel only flags please use an additional argument to do_fork and copy_process. Your current scheme also has the bad side that if user space supplied a kernel flag it is hard to detect it and return -EINVAL. Which limits future expansion. Silently dropping clone flags is a real pain, if you are trying to detect if a new flag has been implemented. Eric