From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753992AbbKWXPm (ORCPT ); Mon, 23 Nov 2015 18:15:42 -0500 Received: from mail-yk0-f179.google.com ([209.85.160.179]:33470 "EHLO mail-yk0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752395AbbKWXPl (ORCPT ); Mon, 23 Nov 2015 18:15:41 -0500 Date: Mon, 23 Nov 2015 18:15:36 -0500 From: Tejun Heo To: Oleg Nesterov Cc: Andrew Morton , Andrey Ryabinin , Roland McGrath , LKML , Pedro Alves , Jan Kratochvil Subject: Re: [PATCH 2/2] ptrace: task_stopped_code(ptrace => true) can't see TASK_STOPPED task Message-ID: <20151123231536.GK19072@mtj.duckdns.org> References: <5640B7F2.70406@virtuozzo.com> <20151119184709.GA19061@redhat.com> <20151119184752.GC19061@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151119184752.GC19061@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 19, 2015 at 07:47:52PM +0100, Oleg Nesterov wrote: > task_stopped_code()->task_is_stopped_or_traced() doesn't look right, > the traced task must never be TASK_STOPPED. > > We can not add WARN_ON(task_is_stopped(p)), but this is only because > do_wait() can race with PTRACE_ATTACH from another thread. > > Signed-off-by: Oleg Nesterov I think it's a left over from before. We used to leave STOPPED tasks alone during ptrace attach. Acked-by: Tejun Heo Thanks. -- tejun