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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 6122CC32771 for ; Thu, 9 Jan 2020 05:20:07 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 1867720678 for ; Thu, 9 Jan 2020 05:20:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="VY10UCpK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1867720678 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.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=cDcYx731uMvoggeyAOD8dp/lssxGSBxeeVDMBEyqmLg=; b=VY10UCpKZmL6nE OCflRerlxCh7AbRM8GE7kbNCJI9ogg0BzVDaatbKbsHYdu8aWbpgHVBHPaX/ImY0bw4G66BclC2Km oUNBCO2V77nMoL8Tk2BNa0pemldwsYnhdKcnxUCSg4HziSlAIpigb/GDPihLygUZ2GMhs7m3TKq2P nNhTbUvxu6gqEejg8CMtCscEjRt9HPCJLVo2B0NNF2FFSirqodh9hHVFyDdZ12LfzTX6sLIB10sXG AICL9kEovwiC5lr7V135VjiEgYoJ0y+QiteauJgm7W6yPRGwoa/MVtbWjOP5VdnoqOlAdIgP2APym ZWJV2LI2Ws0pk72vVoeQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ipQEo-0003RQ-7x; Thu, 09 Jan 2020 05:20:06 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ipQEl-0002no-IF for linux-arm-kernel@lists.infradead.org; Thu, 09 Jan 2020 05:20:04 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 734BB31B; Wed, 8 Jan 2020 21:19:59 -0800 (PST) Received: from [10.162.40.138] (p8cg001049571a15.blr.arm.com [10.162.40.138]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 67AD83F534; Wed, 8 Jan 2020 21:19:56 -0800 (PST) Subject: Re: [PATCH 01/17] arm64: entry: mark all entry code as notrace To: Mark Rutland , linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will@kernel.org, james.morse@arm.com References: <20200108185634.1163-1-mark.rutland@arm.com> <20200108185634.1163-2-mark.rutland@arm.com> From: Anshuman Khandual Message-ID: <6ac3017e-07cb-8ef4-c2e9-22a6fc8d8e24@arm.com> Date: Thu, 9 Jan 2020 10:51:10 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200108185634.1163-2-mark.rutland@arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200108_212003_656198_1E304C2F X-CRM114-Status: GOOD ( 10.68 ) 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: keescook@chromium.org, maz@kernel.org, broonie@kernel.org, labbott@redhat.com, robin.murphy@arm.com, julien.thierry.kdev@gmail.com, alex.popov@linux.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 01/09/2020 12:26 AM, Mark Rutland wrote: > Almost all functions in entry-common.c are marked notrace, with > el1_undef and el1_inv being the only exceptions. We appear to have done > this on the assumption that there were no exception registers that we > needed to snapshot, and thus it was safe to run trace code that might > result in further exceptions and clobber those registers. > > However, until we inherit the DAIF flags, our irq flag tracing is stale, > and this discrepancy could set off warnings in some configurations. Could you give some example scenarios when this might happen ? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel