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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 B7349C433DB for ; Tue, 2 Feb 2021 13:36:31 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 678A664EC5 for ; Tue, 2 Feb 2021 13:36:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 678A664EC5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=q4UURw+q0oH5OzFUk4elFu/3CHSU37UyPH5+WRyE8Ww=; b=qHTV1my66xjvAzbxu1GsgfJZk L6OEj4sR31pKQBlXxsd/FpLNDdmfQ8r3GOQ2CyQTWyaloKB4oOz2Y4Tgb+qDTNVt5TgUL1RxCmC9e g+EoB89VsjNKUvurp06FCEMoVIEmkdNt0Y03apKD6APAhEQaPEsWpo+QSnihUz+/WPrMlfz46hmPa L8LjaquqRseFI1/Ga3xBDxIjECZ+Dfw+z0AI9W5bgEkNt13X4iEINb9wJbC6/3hgq+bPY20CDvSJq 5WH/JsbYDikrV3/FFRDR265sCkD44z58ZLRmjnZdvwoJL7UEQzw+xow6ET4HauoHHLjvzR5VpZTuh coBOqdUJQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6vq3-0002Fx-Vm; Tue, 02 Feb 2021 13:35:28 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6vpz-0002EW-Ru for linux-arm-kernel@lists.infradead.org; Tue, 02 Feb 2021 13:35:24 +0000 Received: from [192.168.254.32] (unknown [47.187.219.45]) by linux.microsoft.com (Postfix) with ESMTPSA id C7A2020B7192; Tue, 2 Feb 2021 05:35:22 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C7A2020B7192 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1612272923; bh=5ZF6yWf5jT1AkU5IIHmVxGOC4jSrecyCU1Gt3I4nEt0=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=T5VgOLeTv1q8aoxKXX3M1YHVhi0geJ8pNwFK2GH/hEsSTql7jbgJVbhBd182kKlso Bcx8f1SJSDIhEHGPxBFVJ4/PGEGM/8G36usTbh6aFOqJYahgamb/cPRfrWUqGmIiGv R0KBctvwoSJyb7asMMbk8fuWVhkAD03YI8DXQ4oc= Subject: Re: [RFC PATCH 0/3] arm64: Implement reliable stack trace To: Mark Rutland References: <20201012172605.10715-1-broonie@kernel.org> <13095563-ff6d-b806-1bf3-efde4383456e@linux.microsoft.com> <20210128142250.GC4537@sirena.org.uk> <20210128152649.6zin3hzim3etbv2p@treble> <20210201160225.GD66060@C02TD0UTHF1T.local> <20210202100547.GA59049@C02TD0UTHF1T.local> From: "Madhavan T. Venkataraman" Message-ID: <312dbbec-2c0d-8e7e-e9f4-9bc8624de055@linux.microsoft.com> Date: Tue, 2 Feb 2021 07:35:21 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210202100547.GA59049@C02TD0UTHF1T.local> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210202_083524_049544_5BAC2450 X-CRM114-Status: GOOD ( 11.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Julien Thierry , Catalin Marinas , Mark Brown , Josh Poimboeuf , Miroslav Benes , Will Deacon , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2/2/21 4:05 AM, Mark Rutland wrote: >> Objtool has to follow all the code paths to check every single possible return >> as I mentioned above. > Here I was pointing out that in order to do so you need to decode and > reason about more than NOP, RET, STP, and LDP, and you need to reason > about the logical function of an instruction (e.g. here the last LDP is > emulating a RET). > Agreed. In addition to the instructions I pointed out, the other control transfer instruction(s) like branches (but not calls) should be decoded. Madhavan _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel