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,URIBL_BLOCKED,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 C5C95C433B4 for ; Thu, 8 Apr 2021 19:23:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9289261105 for ; Thu, 8 Apr 2021 19:23:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232316AbhDHTXx (ORCPT ); Thu, 8 Apr 2021 15:23:53 -0400 Received: from linux.microsoft.com ([13.77.154.182]:54056 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231420AbhDHTXw (ORCPT ); Thu, 8 Apr 2021 15:23:52 -0400 Received: from [192.168.254.32] (unknown [47.187.194.202]) by linux.microsoft.com (Postfix) with ESMTPSA id 77D1220B476F; Thu, 8 Apr 2021 12:23:40 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 77D1220B476F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1617909821; bh=1ucpOVaj4G33S2W7MxZ0QwESYvIN0DIXzPkvhz27OVg=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=L6SzZ58MCWNh1V5W5EzLM2R7xn5e2c9TRu6Q6CRINI5FgpsVBWzfRWQdI56btO5PK nqPt/9ylFdfzYXwKuIZxe+Xe1F3H3d8nOAZGhGp4OK/Q4hgeLTzwjEzIvuzKLqpuY3 HqT/myyRqFcs9Mn73NMenjE28bW3C3aeK2jogkxM= Subject: Re: [RFC PATCH v2 3/4] arm64: Detect FTRACE cases that make the stack trace unreliable To: Mark Brown , mark.rutland@arm.com Cc: jpoimboe@redhat.com, jthierry@redhat.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org References: <705993ccb34a611c75cdae0a8cb1b40f9b218ebd> <20210405204313.21346-1-madvenka@linux.microsoft.com> <20210405204313.21346-4-madvenka@linux.microsoft.com> <20210408165825.GP4516@sirena.org.uk> From: "Madhavan T. Venkataraman" Message-ID: Date: Thu, 8 Apr 2021 14:23:39 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210408165825.GP4516@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: linux-kernel@vger.kernel.org On 4/8/21 11:58 AM, Mark Brown wrote: > On Mon, Apr 05, 2021 at 03:43:12PM -0500, madvenka@linux.microsoft.com wrote: >> From: "Madhavan T. Venkataraman" >> >> When CONFIG_DYNAMIC_FTRACE_WITH_REGS is enabled and tracing is activated >> for a function, the ftrace infrastructure is called for the function at >> the very beginning. Ftrace creates two frames: > > This looks good to me however I'd really like someone who has a firmer > understanding of what ftrace is doing to double check as it is entirely > likely that I am missing cases here, it seems likely that if I am > missing stuff it's extra stuff that needs to be added and we're not > actually making use of the reliability information yet. > OK. So, do you have some specific reviewer(s) in mind? Apart from yourself, Mark Rutland and Josh Poimboeuf, these are some reviewers I can think of (in alphabetical order): AKASHI Takahiro Ard Biesheuvel Catalin Marinas Josh Poimboeuf Steven Rostedt (VMware) Torsten Duwe Will Deacon Sorry if I missed out any of the other experts. Thanks. Madhavan