From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947206AbcHRN1K (ORCPT ); Thu, 18 Aug 2016 09:27:10 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:34902 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1950088AbcHRNZQ (ORCPT ); Thu, 18 Aug 2016 09:25:16 -0400 Date: Thu, 18 Aug 2016 15:25:09 +0200 From: Frederic Weisbecker To: Josh Poimboeuf Cc: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Linus Torvalds , Steven Rostedt , Brian Gerst , Kees Cook , Peter Zijlstra , Byungchul Park , Nilay Vaish Subject: Re: [PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code Message-ID: <20160818132507.GD22490@lerouge> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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, Aug 18, 2016 at 08:05:40AM -0500, Josh Poimboeuf wrote: > > The x86 stack dump code is a bit of a mess. dump_trace() uses > callbacks, and each user of it seems to have slightly different > requirements, so there are several slightly different callbacks floating > around. > > Also there are some upcoming features which will require more changes to > the stack dump code: reliable stack detection for live patching, > hardened user copy, and the DWARF unwinder. Each of those features > would at least need more callbacks and/or callback interfaces, resulting > in a much bigger mess than what we have today. > > Before doing all that, we should try to clean things up and replace > dump_trace() with something cleaner and more flexible. > > The new unwinder is a simple state machine which was heavily inspired by > a suggestion from Andy Lutomirski: > > https://lkml.kernel.org/r/CALCETrUbNTqaM2LRyXGRx=kVLRPeY5A3Pc6k4TtQxF320rUT=w@mail.gmail.com > > It's also similar to the libunwind API: > > http://www.nongnu.org/libunwind/man/libunwind(3).html > > Some if its advantages: > > - simplicity: no more callback sprawl and less code duplication. > > - flexibility: allows the caller to stop and inspect the stack state at > each step in the unwinding process. > > - modularity: the unwinder code, console stack dump code, and stack > metadata analysis code are all better separated so that changing one > of them shouldn't have much of an impact on any of the others. > > ---- > > Josh Poimboeuf (57): I am personally unable to review a 57 patches series. Any chance you could split it into self-contained steps? In general doing so increase the chances for reviews, accelerate merging, improve maintainance... Thanks.