From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752374AbcADHvn (ORCPT ); Mon, 4 Jan 2016 02:51:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37156 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751118AbcADHvi (ORCPT ); Mon, 4 Jan 2016 02:51:38 -0500 Date: Mon, 4 Jan 2016 02:51:29 -0500 From: Richard Guy Briggs To: Sergey Senozhatsky Cc: "Serge E. Hallyn" , Sergey Senozhatsky , Oleg Nesterov , Peter Zijlstra , Andrew Morton , "Eric W. Biederman" , "Serge E. Hallyn" , linux-kernel@vger.kernel.org Subject: Re: [RFC] is_global_init() called on global init sub-thread Message-ID: <20160104075129.GA11244@madcap2.tricolour.ca> References: <20151230062542.GA605@swordfish> <20160101010823.GB26243@mail.hallyn.com> <20160101011035.GA538@swordfish> <20160101011831.GA26628@mail.hallyn.com> <20160101013353.GB532@swordfish> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160101013353.GB532@swordfish> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/01/01, Sergey Senozhatsky wrote: > On (12/31/15 19:18), Serge E. Hallyn wrote: > > On Fri, Jan 01, 2016 at 10:10:35AM +0900, Sergey Senozhatsky wrote: > > > On (12/31/15 19:08), Serge E. Hallyn wrote: > > > > > re-upping https://www.redhat.com/archives/linux-audit/2013-December/msg00086.html > > > > > > > > > > Oleg Nesterov wrote: > > > > > > > > > > :Because is_global_init() is only true for the main thread of /sbin/init. > > > > > : > > > > > :Just look at oom_unkillable_task(). It tries to not kill init. But, say, > > > > > :select_bad_process() can happily find a sub-thread of is_global_init() > > > > > :and still kill it. > > > > > > > > > > this is still the case, isn't it? at least in some -stable kernels. > > > > > is there (or was there) any reason this change has never been committed? > > > > > (I'm particularly interested in is_global_init()). > > > > > > > > ... seems like it makes sense. Can you remind us which init you're having > > > > to deal with? > > > > > > > > > > systemd > > > > > > -ss > > > > Well it makes sense to me. The question is whether we are protecting the > > thing running as init, or the 'physical' thread with pid 1. I think it's > > the former, so let's push on this. Please resend the patch with a proper > > signed-off-by, and feel free to add > > thanks. a bit puzzled, would reported-by Oleg and suggested-by Richard > be appropriate? (no objections if Oleg or Richard will submit it). This works for me. I have more patches related to it, but I'll re-submit them later. > > Acked-by: Serge Hallyn > > -ss - RGB -- Richard Guy Briggs Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat Remote, Ottawa, Canada Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545