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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no 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 CF686C433FF for ; Thu, 8 Aug 2019 16:36:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EAE72173C for ; Thu, 8 Aug 2019 16:36:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390153AbfHHQgf (ORCPT ); Thu, 8 Aug 2019 12:36:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:49744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725535AbfHHQgf (ORCPT ); Thu, 8 Aug 2019 12:36:35 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E61AE214C6; Thu, 8 Aug 2019 16:36:33 +0000 (UTC) Date: Thu, 8 Aug 2019 12:36:32 -0400 From: Steven Rostedt To: Will Deacon Cc: linux-kernel@vger.kernel.org, Jiping Ma , catalin.marinas@arm.com, will.deacon@arm.com, mingo@redhat.com, Joel Fernandes , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 1/2 v2] tracing/arm64: Have max stack tracer handle the case of return address after data Message-ID: <20190808123632.0dd1a58c@gandalf.local.home> In-Reply-To: <20190808162825.7klpu3ffza5zxwrt@willie-the-truck> References: <20190807172826.352574408@goodmis.org> <20190807172907.155165959@goodmis.org> <20190808162825.7klpu3ffza5zxwrt@willie-the-truck> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 8 Aug 2019 17:28:26 +0100 Will Deacon wrote: > > + * Note, this may change in the future, and we will need to deal with that > > + * if it were to happen. > > + */ > > +#define ARCH_RET_ADDR_AFTER_LOCAL_VARS 1 > > I know it's long already, but prefixing this with FTRACE_ would be good so > that other code doesn't use it for anything. It's not the end of the world > if the ftrace stack usage statistics are wonky, but if people tried to use > this for crazy things like livepatching then we'd be in trouble. > > Maybe FTRACE_ARCH_FRAME_AFTER_LOCALS, which is the same length as what > you currently have? Note, it would still need to be prefixed with "ARCH_" as that's the way of showing arch specific defines. We could make it more descriptive of what it will do and not the reason for why it is done... ARCH_FTRACE_SHIFT_STACK_TRACER ? -- Steve