From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753970AbaLBI7x (ORCPT ); Tue, 2 Dec 2014 03:59:53 -0500 Received: from mail-wi0-f173.google.com ([209.85.212.173]:50534 "EHLO mail-wi0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752089AbaLBI7w (ORCPT ); Tue, 2 Dec 2014 03:59:52 -0500 Date: Tue, 2 Dec 2014 09:59:49 +0100 From: Michal Hocko To: Oleg Nesterov Cc: Cong Wang , "Rafael J. Wysocki" , Tejun Heo , David Rientjes , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: oom && coredump Message-ID: <20141202085949.GA27014@dhcp22.suse.cz> References: <20141017171904.GA12263@redhat.com> <20141020184657.GA505@dhcp22.suse.cz> <20141020190620.GA21882@redhat.com> <20141020195618.GA606@redhat.com> <20141127122908.GB18833@dhcp22.suse.cz> <20141127174747.GA7684@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141127174747.GA7684@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 27-11-14 18:47:47, Oleg Nesterov wrote: > On 11/27, Michal Hocko wrote: [...] > > Why is the ptrace check wrong? > > It was added in reply to exploit I sent. But: > > - It doesn't (and can't) really work, it can only detect this particular > case and the same exploit still blocks oom-killer with the minimal > modifications. > > - Once again, this has nothing to do with ptrace. That exploit used > ptrace only to control (freeze) the coredumping process, the coredumping > can "hang" because of other reasons. > > - It is no longer needed after this patch, the coredumping process will > be killed. OK, I guess I am seeing it now. Thanks for the clarification! [...] -- Michal Hocko SUSE Labs