From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753780AbcIOShy (ORCPT ); Thu, 15 Sep 2016 14:37:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37334 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751704AbcIOShn (ORCPT ); Thu, 15 Sep 2016 14:37:43 -0400 Date: Thu, 15 Sep 2016 13:37:41 -0500 From: Josh Poimboeuf To: Andy Lutomirski Cc: Andy Lutomirski , X86 ML , Borislav Petkov , "linux-kernel@vger.kernel.org" , Brian Gerst , Jann Horn Subject: Re: [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Message-ID: <20160915183741.wka5dzdsvbn53drp@treble> References: <7cd5e328dc75d8ccd912e5783665de34503f7c63.1473801993.git.luto@kernel.org> <20160914145556.5whqcpzys7c23nib@treble> <20160914183501.cknjhsbkzxg6m6pl@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.0.1 (2016-04-01) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Thu, 15 Sep 2016 18:37:43 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 15, 2016 at 11:04:47AM -0700, Andy Lutomirski wrote: > On Wed, Sep 14, 2016 at 11:35 AM, Josh Poimboeuf wrote: > > On Wed, Sep 14, 2016 at 11:22:00AM -0700, Andy Lutomirski wrote: > >> On Wed, Sep 14, 2016 at 7:55 AM, Josh Poimboeuf wrote: > >> > On Tue, Sep 13, 2016 at 02:29:28PM -0700, Andy Lutomirski wrote: > >> >> This will prevent a crash if the target task dies before or while > >> >> dumping its stack once we start freeing task stacks early. > >> >> > >> >> Signed-off-by: Andy Lutomirski > >> > > >> > Do we need a similar patch for show_stack()? > >> > >> Probably. Shouldn't it go in show_stack_log_lvl() instead, though? > > > > Yeah, that would probably be better. > > This code is a colossal mess. I really hope that, some day, we can > clarify which entry points are used only in dumpstack*.c and which are > used elsewhere. Creating an arch/x86/kernel/dumpstack.h or just > merging the three files and removing all the intermediate crap from > the headers could help a lot. Agreed, it's a mess, though it's improving with some of my changes. dumpstack_32.c and dumpstack_64.c will be shrinking, with dump_trace() getting removed. And they'll be shrinking even more with Linus's suggestion to remove show_stack_log_lvl(). Then maybe we can look at merging those two files into dumpstack.c with an #ifdef to separate the subarch differences. -- Josh