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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 42D97C282D8 for ; Fri, 1 Feb 2019 10:51:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F79D21916 for ; Fri, 1 Feb 2019 10:51:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729918AbfBAKvz (ORCPT ); Fri, 1 Feb 2019 05:51:55 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:57826 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729451AbfBAKvz (ORCPT ); Fri, 1 Feb 2019 05:51:55 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AD6B280D; Fri, 1 Feb 2019 02:51:54 -0800 (PST) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7A82B3F71E; Fri, 1 Feb 2019 02:51:53 -0800 (PST) Date: Fri, 1 Feb 2019 10:51:44 +0000 From: Will Deacon To: "Zhang, Lei" Cc: 'James Morse' , 'Mark Rutland' , 'Catalin Marinas' , "'linux-kernel@vger.kernel.org'" , "'linux-arm-kernel@lists.infradead.org'" Subject: Re: [PATCH v3 0/1] arm64: Add workaround for Fujitsu A64FX erratum 010001 Message-ID: <20190201105144.GA27140@fuggles.cambridge.arm.com> References: <8898674D84E3B24BA3A2D289B872026A6A2C04E6@G01JPEXMBKW03> <8898674D84E3B24BA3A2D289B872026A6A3090AC@G01JPEXMBKW03> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <8898674D84E3B24BA3A2D289B872026A6A3090AC@G01JPEXMBKW03> User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 01, 2019 at 05:53:50AM +0000, Zhang, Lei wrote: > > -----Original Message----- > > From: linux-arm-kernel > > [mailto:linux-arm-kernel-bounces@lists.infradead.org] On Behalf Of > > James Morse > > Sent: Thursday, January 31, 2019 12:00 AM > > To: Zhang, Lei/張 雷 > > Cc: 'Mark Rutland'; 'Catalin Marinas'; 'will.deacon@arm.com'; > > 'linux-kernel@vger.kernel.org'; > > 'linux-arm-kernel@lists.infradead.org' > > Subject: Re: [PATCH v3 0/1] arm64: Add workaround for Fujitsu A64FX > > erratum 010001 > > > > > > e03e61c3173c ("arm64: kaslr: Set TCR_EL1.NFD1 when > > CONFIG_RANDOMIZE_BASE=y") ? > > > > So you'd never see it if you disabled CONFIG_RANDOMIZE_BASE? > For security, it is necessary to set CONFIG_RANDOMIZE_BASE=y. So I guess we should boot with NFD1 clear, and then set it only when we realise we're not on an A64FX? Will