From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932144AbbKQQ50 (ORCPT ); Tue, 17 Nov 2015 11:57:26 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34078 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753888AbbKQQ5L (ORCPT ); Tue, 17 Nov 2015 11:57:11 -0500 Date: Tue, 17 Nov 2015 18:53:09 +0100 From: Oleg Nesterov To: Tejun Heo Cc: Ingo Molnar , Peter Zijlstra , Milos Vyletel , Prarit Bhargava , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/8] stop_machine: cpu_stopper_thread() must check done != NULL Message-ID: <20151117175309.GA16154@redhat.com> References: <20151115193254.GA8225@redhat.com> <20151115193311.GA8242@redhat.com> <20151116185221.GK18894@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151116185221.GK18894@mtj.duckdns.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/16, Tejun Heo wrote: > > On Sun, Nov 15, 2015 at 08:33:11PM +0100, Oleg Nesterov wrote: > > stop_one_cpu_nowait(fn) will crash the kernel if the callback returns > > nonzero, work->done == NULL in this case. > > > > This needs more cleanups, cpu_stop_signal_done() is called right after > > we check done != NULL and it does the same check. > > > > Signed-off-by: Oleg Nesterov > > Acked-by: Tejun Heo Thanks! > cc stable? Yes, I was going to add -stable initially. And perhaps this makes sense anyway, the patch is really trivial. OTOH I have checked the history, none of cpu_stop_signal_done's callbacks ever returned non-zero, so I decided to not spam -stable. Oleg.