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=-5.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 C07F4C54FC9 for ; Tue, 21 Apr 2020 12:31:58 +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 8CC8C2076E for ; Tue, 21 Apr 2020 12:31:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="c2l6lKu9"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="kIH1xpTa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8CC8C2076E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uXxDNhVVua5cjAOVBgukumP/V8OFYriHcb4rId9EQSU=; b=c2l6lKu9uIEppT CappnDxEko3qj3viDJPOOWXhhKDrDlkNrcqLpk+eo5fHLlmfEroOMyY0XCiVo6adsoRRSR9jPnwE9 HzjpFOE4RUyUCHbhiM0wGCWKm/IKmXn1BjvkYutbKO6EIEA2mpbqx7QKDLJQk9uv7hVM/eTCLxIUl pIXi0No3EAcij/gw3TxviZUGNAfjEL769wTmPFEt8y/dbp9tUcCZanxtH1k4ooVlCIWlrdJCG9dso Y6hQHzodFi/y/oJE0RKNJiK3IyAxXGIlMBDZMCubClLkQCMaReunQZ10RnQ9hLrFJoswOK8lOqifo bC29XySdebEdm137V9mg==; 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 1jQs4E-0000T3-7a; Tue, 21 Apr 2020 12:31:58 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jQs4C-0000Rw-3T for linux-arm-kernel@lists.infradead.org; Tue, 21 Apr 2020 12:31:57 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 903E42070B; Tue, 21 Apr 2020 12:31:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587472315; bh=giULxdNXPzDCnwQ0D0j+NlFvih/Iz/GiAcWHzMDKaX8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kIH1xpTac4Ypo0E7ABszu7rfMZ3nqHk+wJR2p6TUUcHPmBiFzmrFqg/jqp1ET39hX qjNtLbaCOMAgCS14YwxXwziewd3RTwrrHU78911Hu/ALiyd3Pd2iIw3t/IAtkNXN0n DMl/9hYHuSmart12B9HChOqahVYJlOIsJq+0rJ04= Date: Tue, 21 Apr 2020 13:31:51 +0100 From: Will Deacon To: Mark Rutland Subject: Re: [PATCH] arm64: sync kernel APIAKey when installing Message-ID: <20200421123150.GA17875@willie-the-truck> References: <20200421121014.53120-1-mark.rutland@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200421121014.53120-1-mark.rutland@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200421_053156_163377_EF5FEAB7 X-CRM114-Status: GOOD ( 14.08 ) 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: Amit Daniel Kachhap , Catalin Marinas , linux-arm-kernel@lists.infradead.org, Marc Zyngier 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 Tue, Apr 21, 2020 at 01:10:14PM +0100, Mark Rutland wrote: > A direct write to a APxxKey_EL1 register requires a context > synchronization event to ensure that indirect reads made by subsequent > instructions (e.g. AUTIASP, PACIASP) observe the new value. > > When we initialize the boot task's APIAKey in boot_init_stack_canary() > via ptrauth_keys_switch_kernel() we miss the necessary ISB, and so there > is a window where instructions are not guaranteed to use the new APIAKey > value. This has been observed to result in boot-time crashes where > PACIASP and AUTIASP within a function used a mixture of the old and new > key values. > > Fix this by having ptrauth_keys_switch_kernel() synchronize the new key > value with an ISB. At the same time, __ptrauth_key_install() is renamed > to __ptrauth_key_install_nosync() so that it is obvious that this > performs no synchronization itself. > > Fixes: 28321582334c261c ("arm64: initialize ptrauth keys for kernel booting task") > Signed-off-by: Mark Rutland > Reported-by: Will Deacon > Cc: Amit Daniel Kachhap > Cc: Catalin Marinas > Cc: Marc Zyngier > --- > arch/arm64/include/asm/pointer_auth.h | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) Tested-by: Will Deacon Catalin -- please can you queue this for -rc3? Cheers, Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel