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 C3E38C10DCE for ; Thu, 12 Mar 2020 06:53:25 +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 B336320578 for ; Thu, 12 Mar 2020 06:53:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="bNYl5ui8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B336320578 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=uyhQIkuPWgkUBL7Y1AC4C5h0XMabjPSwhWxaZ3nbajQ=; b=bNYl5ui8G2qef0G4fjwhPauvl 2brQlG94mseSxWGutcdisoiW8ggWOp5Ix3FH4UaJu6lxSWA5IUxz7fY1KYW+rIlSCgISu4EOWFcVv zJjNCfOGVHx8xMSfnAe+I6xZc/F5h3AgF7On5GyICvqxXZA88sOJad4EIZ7KOutSe8wqDkoj4PtSb F8FS6RZ7acffs8VuBQzN+yq8XGRH+IBoqovDywxmEXXoD0dCh3FkPnpp09IqjVc9xcfnSpj21DRrW 40VjG4DUlETG0xZUMDTyUAzaoZaGXv4w62LTQWirsGxU721ub9xBkX7++QOh7BXHekJF87dYJsqRJ pe9gS4g1A==; 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 1jCHic-0004np-8Q; Thu, 12 Mar 2020 06:53:22 +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 1jCHiZ-0004n1-Bt for linux-arm-kernel@lists.infradead.org; Thu, 12 Mar 2020 06:53:20 +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 AD3CA30E; Wed, 11 Mar 2020 23:53:14 -0700 (PDT) Received: from [10.162.16.120] (a075563-lin.blr.arm.com [10.162.16.120]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id ADAC33F534; Wed, 11 Mar 2020 23:57:09 -0700 (PDT) Subject: Re: [PATCH v6 00/18] arm64: return address signing To: James Morse References: <1583476525-13505-1-git-send-email-amit.kachhap@arm.com> From: Amit Kachhap Message-ID: <79a45ce2-a632-9821-986e-1f48cb0121c9@arm.com> Date: Thu, 12 Mar 2020 12:23:12 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200311_235319_451753_BD6D412C X-CRM114-Status: GOOD ( 15.81 ) 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: Mark Rutland , Marc Zyngier , Kees Cook , Suzuki K Poulose , Catalin Marinas , Kristina Martsenko , Dave Martin , Mark Brown , Ramana Radhakrishnan , Vincenzo Frascino , Will Deacon , Ard Biesheuvel , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi James, On 3/11/20 2:58 PM, James Morse wrote: > Hi Amit, > > (CC: +Marc) > > On 3/6/20 6:35 AM, Amit Daniel Kachhap wrote: >> This series improves function return address protection for the arm64 kernel, by >> compiling the kernel with ARMv8.3 Pointer Authentication instructions (referred >> ptrauth hereafter). This should help protect the kernel against attacks using >> return-oriented programming. > > (as it looks like there may be another version of this:) > > Am I right in thinking that after your patch 10 changing > cpu_switch_to(), only the A key is live during kernel execution? Yes > > KVM is still save/restoring 4 extra keys around guest-entry/exit. As you > restore all the keys on return to user-space, is this still necessary? Yes Its a good optimization to skip 4 non-A keys. I was wondering whether to do it in this series or send it separately. Cheers, Amit Daniel > > (insert cross-tree headache here) > > > Thanks, > > James > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel