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,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 80812C433E0 for ; Fri, 5 Jun 2020 13:23:42 +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 4FE87206E6 for ; Fri, 5 Jun 2020 13:23:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="bWX+iSPz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4FE87206E6 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-Type: Content-Transfer-Encoding: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=8UDi/7HZYmcU/MZxeO35VpVFSE81se5De2h76sCA+kc=; b=bWX+iSPzORmvBkUckSR9uMPr2 lIV6fyI7XOKnoSZcc6A0z6ZfKMLTRMrn7EeGrKUn/oGSUmLFgY6U57T6fmKCe1tgcsKdBnSEdEH+R AFG60UXP/LOyHPzfbE+qZv/36Qk93/iRbsMgtE271ZWU/CZZXpVRfXMUpsJY35BelXyAQVTc++yVb ZDuj8uFfGrIwGzEeBcWw+KHnLAn44ljN8cOzXM+wZ50Su8RdT9KPSmOXCj8cSr628u5QccpwPPoVW QB0sbBeaednLFba4uDLmX85C1yjmdnERxLx6Lm19slKygFT4v8NoHdSCA2gM9/JSb1J46bocoiweO Mp3We14QQ==; 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 1jhCJw-0006Il-Vi; Fri, 05 Jun 2020 13:23:40 +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 1jhCJu-0006ID-DM for linux-arm-kernel@lists.infradead.org; Fri, 05 Jun 2020 13:23:40 +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 4F84331B; Fri, 5 Jun 2020 06:23:36 -0700 (PDT) Received: from [10.57.10.23] (unknown [10.57.10.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 28FEE3F305; Fri, 5 Jun 2020 06:23:34 -0700 (PDT) Subject: Re: Please help to confirm the risk if using TPIDRRO_EL0 to save CPU number, thanks. To: Will Deacon References: <1D289F1E6D91D2489524BBB0B8880A7DA1A39219@dggeml509-mbx.china.huawei.com> <20200601070311.GA8601@willie-the-truck> <20200605121029.GE5413@sirena.org.uk> <20200605123302.GA19936@willie-the-truck> <20200605130251.GB20441@willie-the-truck> From: Robin Murphy Message-ID: Date: Fri, 5 Jun 2020 14:23:32 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200605130251.GB20441@willie-the-truck> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200605_062338_537442_BA4B2819 X-CRM114-Status: GOOD ( 20.05 ) 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: "fujun \(F\)" , Mark Brown , Wuxuecheng , "Lixin \(Victor, Kirin\)" , "linux-arm-kernel@lists.infradead.org" Content-Transfer-Encoding: base64 Content-Type: text/plain; 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