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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 0E309C54FC9 for ; Tue, 21 Apr 2020 13:32:09 +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 B851F206F4 for ; Tue, 21 Apr 2020 13:32:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="FB3dWKvP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B851F206F4 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: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=XAlUw629O1UXGOej34su7aSRoianoYw8N5FgpyfbfzM=; b=FB3dWKvPrehr/B MGpMNpunueviSpMW5O6Jm2rEZccoOjBP65CjyJrgPDsA4qanlqDONTnqaNVoPnDan/kvEhW/9QH8T aSk4/dIGQLfZS69jTZlLmIsa4mGTsicaaxPXNnFY/52KGxAE6qNX7s8QXnbYCjsmpH1j+RESKd99l cyvGt68COXYGgccg6g/cqquojJ9kI2l92g+/ImAbbepJms4DsVR1QjN44e7RiMDUMbPxuLtCmqtV/ pal9ca6baPLKvXxuxMPqltI+54fL1TDimrjYkHbe5TOuKxoPRk4y9QPH3qABpO+bD/L4tNtCsxkVx zROFS1a2FAPD4uVUPZ2A==; 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 1jQt0O-00078E-RP; Tue, 21 Apr 2020 13:32:04 +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 1jQt0L-00076Y-CG for linux-arm-kernel@lists.infradead.org; Tue, 21 Apr 2020 13:32:02 +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 6F5A531B; Tue, 21 Apr 2020 06:31:57 -0700 (PDT) Received: from gaia (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 925E73F68F; Tue, 21 Apr 2020 06:31:56 -0700 (PDT) Date: Tue, 21 Apr 2020 14:31:54 +0100 From: Catalin Marinas To: Will Deacon Subject: Re: [PATCH] arm64: sync kernel APIAKey when installing Message-ID: <20200421133153.GB12076@gaia> References: <20200421121014.53120-1-mark.rutland@arm.com> <20200421123150.GA17875@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200421123150.GA17875@willie-the-truck> 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_063201_459371_23174BF4 X-CRM114-Status: GOOD ( 17.10 ) 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 , Amit Daniel Kachhap , 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 01:31:51PM +0100, Will Deacon wrote: > 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? I will. Thanks. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel