From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23577C432BE for ; Thu, 26 Aug 2021 23:19:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 031B560FE6 for ; Thu, 26 Aug 2021 23:19:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243671AbhHZXT6 (ORCPT ); Thu, 26 Aug 2021 19:19:58 -0400 Received: from linux.microsoft.com ([13.77.154.182]:36022 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234555AbhHZXT5 (ORCPT ); Thu, 26 Aug 2021 19:19:57 -0400 Received: from [192.168.254.32] (unknown [47.187.212.181]) by linux.microsoft.com (Postfix) with ESMTPSA id 8A5A420B861E; Thu, 26 Aug 2021 16:19:08 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8A5A420B861E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1630019949; bh=TNk71oULKpnJVXpIAkpW4dxCRZZFfi0WY/GV0rQ4Blw=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=sDrPH0DIYqzWljDeynFQ2cHN8Shft6uXuyS4L8KXZr4/VtcLamVAxWh5cQW0bRTzZ jRY4voAsLQE2MfrL7Lxe/Oqs/DQ0JxZFajO2NvhnOok99Bv9D9JJvywU8FT7g7p6vD vtYq3ii0I1E1jMYUrrV4jbhwRbx90qfjp7fFyjq4= Subject: Re: [RFC PATCH v8 2/4] arm64: Reorganize the unwinder code for better consistency and maintenance To: Mark Brown Cc: mark.rutland@arm.com, jpoimboe@redhat.com, ardb@kernel.org, nobuta.keiya@fujitsu.com, sjitindarsingh@gmail.com, catalin.marinas@arm.com, will@kernel.org, jmorris@namei.org, pasha.tatashin@soleen.com, jthierry@redhat.com, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210812190603.25326-1-madvenka@linux.microsoft.com> <20210812190603.25326-3-madvenka@linux.microsoft.com> From: "Madhavan T. Venkataraman" Message-ID: Date: Thu, 26 Aug 2021 18:19:07 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org On 8/26/21 10:46 AM, Mark Brown wrote: > On Thu, Aug 12, 2021 at 02:06:01PM -0500, madvenka@linux.microsoft.com wrote: > >> Renaming of unwinder functions >> ============================== > >> Rename unwinder functions to unwind_*() similar to other architectures >> for naming consistency. More on this below. > > This feels like it could probably do with splitting up a bit for > reviewability, several of these headers you've got in the commit > logs look like they could be separate commits. Splitting things > up does help with reviewability, having only one change to keep > in mind at once is a lot less cognative load. > >> Replace walk_stackframe() with unwind() >> ======================================= >> >> walk_stackframe() contains the unwinder loop that walks the stack >> frames. Currently, start_backtrace() and walk_stackframe() are called >> separately. They should be combined in the same function. Also, the >> loop in walk_stackframe() should be simplified and should look like >> the unwind loops in other architectures such as X86 and S390. > > This definitely seems like a separate change. > OK. I will take a look at splitting the patch. I am also requesting a review of the sym_code special section approach. I know that you have already approved it. I wanted one more vote. Then, I can remove the "RFC" word from the title and then it will be just a code review of the patch series. Mark Rutland, Do you also approve the idea of placing unreliable functions (from an unwind perspective) in a special section and using that in the unwinder for reliable stack trace? Thanks. Madhavan