From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2507CC432C0 for ; Thu, 21 Nov 2019 11:27:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED10120714 for ; Thu, 21 Nov 2019 11:27:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726554AbfKUL1a (ORCPT ); Thu, 21 Nov 2019 06:27:30 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:48327 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726342AbfKUL1a (ORCPT ); Thu, 21 Nov 2019 06:27:30 -0500 Received: from [79.140.122.151] (helo=wittgenstein) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iXkcL-0005p8-6z; Thu, 21 Nov 2019 11:27:21 +0000 Date: Thu, 21 Nov 2019 12:27:20 +0100 From: Christian Brauner To: "Michael Kerrisk (man-pages)" Cc: Christian Brauner , adrian@lisas.de, akpm@linux-foundation.org, arnd@arndb.de, avagin@gmail.com, dhowells@redhat.com, fweimer@redhat.com, jannh@google.com, keescook@chromium.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-man@vger.kernel.org, mingo@elte.hu, oleg@redhat.com, xemul@virtuozzo.com Subject: Re: [PATCH] clone.2: Mention that CLONE_PARENT is off-limits for inits Message-ID: <20191121112719.lg3qxptnowjkpxlg@wittgenstein> References: <20191120104504.22411-1-christian@brauner.io> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Sender: linux-man-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-man@vger.kernel.org On Thu, Nov 21, 2019 at 10:53:50AM +0100, Michael Kerrisk (man-pages) wrote: > Hello Christian, > > On 11/20/19 11:45 AM, Christian Brauner wrote: > > From: Christian Brauner > > > > The CLONE_PARENT flag cannot but used by init processes. Let's mention > > this in the manpages to prevent suprises. > > > > Signed-off-by: Christian Brauner > > --- > > man2/clone.2 | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/man2/clone.2 b/man2/clone.2 > > index f0f29d6f1..aa98ab79b 100644 > > --- a/man2/clone.2 > > +++ b/man2/clone.2 > > @@ -646,6 +646,13 @@ if > > .B CLONE_PARENT > > is set, then the parent of the calling process, rather than the > > calling process itself, will be signaled. > > +.IP > > +The kernel will not allow global init and init processes in pid > > +namespaces to use the > > +.B CLONE_PARENT > > +flag. This is done to prevent the creation of multi-rooted process > > +trees. It also avoids unreapable zombies in the initial pid > > +namespace. > > .TP > > .BR CLONE_PARENT_SETTID " (since Linux 2.5.49)" > > Store the child thread ID at the location pointed to by > > Thank. I applied, and then tweaked the text a little, > and noted the associated EINVAL error. In the end, the > change is as below. Thanks! Christian