From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422996AbcFMV67 (ORCPT ); Mon, 13 Jun 2016 17:58:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50571 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422854AbcFMV65 (ORCPT ); Mon, 13 Jun 2016 17:58:57 -0400 Date: Mon, 13 Jun 2016 16:58:55 -0500 From: Josh Poimboeuf To: Jiri Slaby Cc: Miroslav Benes , Jiri Kosina , Jessica Yu , linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Vojtech Pavlik Subject: Re: [RFC PATCH v1.9 07/14] x86/stacktrace: add function for detecting reliable stack traces Message-ID: <20160613215855.66xvswctxdy2bbrj@treble> References: <1f8c648ed8b8eb49a75f5a6cacf8b7ca76f44fa9.1458933243.git.jpoimboe@redhat.com> <20160404175437.gjj2ghphzv5foh4j@treble.redhat.com> <570BB1AE.6090502@suse.cz> <20160412155658.uuz5jbtnmw3teaey@treble> <91e1f8fc-1a97-709c-3846-16b9ce694246@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <91e1f8fc-1a97-709c-3846-16b9ce694246@suse.cz> 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 [10.5.110.28]); Mon, 13 Jun 2016 21:58:56 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 09, 2016 at 10:31:01AM +0200, Jiri Slaby wrote: > On 04/12/2016, 05:56 PM, Josh Poimboeuf wrote: > >> We had been using unwinder for over a decade in SUSE but it stopped > >> working for assembly recently (for obvious reasons). So having a working > >> and reliable unwinder again is one of the top priorities for us. > > > > Since you already have an unwinder in SUSE, it sounds like what you need > > most urgently is DWARF generation support in objtool so that your > > unwinder will work again for asm code, right? The kernel already emits > > DWARF today (for C code), so an upstream unwinder isn't needed first. > > Right, that's exact. > > > That's high on my TODO list, and the coding is probably 70-80% done. I > > don't want to hold up progress... But I don't really feel comfortable > > passing the code off because it's quite a big feature with some major > > changes to objtool. Being the objtool author, I want to make sure to > > give it my full attention. > > Sure. There is going to be no pressure to merge the v1 of the changes. > But it would be nice to see what you have now so that we can start > reviewing and proposing patches on the top of what you have :). The code is still quite a mess and doesn't even work yet. I think it would be counterproductive for everybody if I were to share it at this stage. > > I'm spread quite thin at the moment but I do hope to have v1 of those > > patches soon, hopefully May-ish. > > So I hope we will see something we can start working on now. I can > really dedicate one-man hours to that work. I do appreciate your offer to help. Hopefully soon I'll get it to at least a decently working and halfway readable state, and then I'll post it. Then any help will be much appreciated. -- Josh