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=-14.8 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=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 A2146C433ED for ; Thu, 6 May 2021 15:20:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D88D6109E for ; Thu, 6 May 2021 15:20:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231673AbhEFPVg (ORCPT ); Thu, 6 May 2021 11:21:36 -0400 Received: from linux.microsoft.com ([13.77.154.182]:38232 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235036AbhEFPVf (ORCPT ); Thu, 6 May 2021 11:21:35 -0400 Received: from [192.168.254.32] (unknown [47.187.223.33]) by linux.microsoft.com (Postfix) with ESMTPSA id BC3BD20B7178; Thu, 6 May 2021 08:20:36 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com BC3BD20B7178 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1620314437; bh=38FJmBMm62FNJbAmIqdoifYxsyXAhfVcnNsSEdMBgD0=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=BbcudnTW8r91m0v0K6ZtId3NOAYF0iHC2oWz4Ak1nCNi51+ES7ZOm0nmyx40i5cXC ZTW07gTcvVC6MJwR0BfbC+UvozkBqY/AJs3xNtgokGh97WHq2mAOQos1TbbIz3GsMm QkbVo2oH0N9c/dD/sgmUgkooiru1wlGmlBWYwAms= Subject: Re: [RFC PATCH v3 4/4] arm64: Handle funtion graph tracer better in the unwinder To: Mark Brown Cc: jpoimboe@redhat.com, mark.rutland@arm.com, jthierry@redhat.com, catalin.marinas@arm.com, will@kernel.org, jmorris@namei.org, pasha.tatashin@soleen.com, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org References: <65cf4dfbc439b010b50a0c46ec500432acde86d6> <20210503173615.21576-1-madvenka@linux.microsoft.com> <20210503173615.21576-5-madvenka@linux.microsoft.com> <20210506144352.GF4642@sirena.org.uk> From: "Madhavan T. Venkataraman" Message-ID: Date: Thu, 6 May 2021 10:20:35 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210506144352.GF4642@sirena.org.uk> 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 5/6/21 9:43 AM, Mark Brown wrote: > On Mon, May 03, 2021 at 12:36:15PM -0500, madvenka@linux.microsoft.com wrote: >> From: "Madhavan T. Venkataraman" >> >> The Function Graph Tracer modifies the return address of a traced function >> to a return trampoline (return_to_handler()) to gather tracing data on >> function return. When the unwinder encounters return_to_handler(), it calls >> ftrace_graph_get_ret_stack() to lookup the original return address in the >> return address stack. > > This makes sense to me, I'll need to re-review properly with the changes > earlier on in the series but should be fine. > I will make changes based on the comments I have received so far and send out version 4 so everything is current for the next round of review. Thanks! Madhavan