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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 07D50C64E7B for ; Tue, 1 Dec 2020 11:27:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91B6320709 for ; Tue, 1 Dec 2020 11:27:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="BojY9Lhb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727957AbgLAL1e (ORCPT ); Tue, 1 Dec 2020 06:27:34 -0500 Received: from mail.skyhub.de ([5.9.137.197]:50908 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727722AbgLAL1d (ORCPT ); Tue, 1 Dec 2020 06:27:33 -0500 Received: from zn.tnic (p200300ec2f0e6a00835f506c18984427.dip0.t-ipconnect.de [IPv6:2003:ec:2f0e:6a00:835f:506c:1898:4427]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id A33A01EC03CE; Tue, 1 Dec 2020 12:26:51 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1606822011; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=kG05JigLq40d1naxqpJ6O+B10zBDQJXKWSq7mQrphYg=; b=BojY9LhbBSwQ8ArzVxrc7xJmMa4uIFOav+p30OL3Syx6JraGb//TATTYxZZJFIjUiez9A2 09xGNqYRskkRNf8Xc1CMYnDSWvJuTK+AxDFujk4khnAeCy1t2Vo04v1Br8C9dwrmoUNa3h q7gIMGzlZ3iVWvjaihbgym07HcKoVjU= Date: Tue, 1 Dec 2020 12:26:47 +0100 From: Borislav Petkov To: wangrongwei Cc: catalin.marinas@arm.com, Will Deacon , bjorn.andersson@linaro.org, shawnguo@kernel.org, vkoul@kernel.org, geert+renesas@glider.be, Anson.Huang@nxp.com, michael@walle.cc, krzk@kernel.org, olof@lixom.net, vincenzo.frascino@arm.com, ardb@kernel.org, masahiroy@kernel.org, gshan@redhat.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] arm64:msr: Add MSR driver Message-ID: <20201201112647.GA22927@zn.tnic> References: <20201130174833.41315-1-rongwei.wang@linux.alibaba.com> <20201130190331.GI6019@zn.tnic> <8724DF91-5BF0-4265-8091-F9E0C7DC2F1A@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <8724DF91-5BF0-4265-8091-F9E0C7DC2F1A@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 01, 2020 at 11:44:52AM +0800, wangrongwei wrote: > Indeed, I have read the commit message, and it seems that writes data > to a system register may cause many problems. Actually, we have taken > this into account. In the current version, we have separated the read > and write functions to the system registers into two commands, There's rdmsr and wrmsr in msr-tools on x86 too. > In providing the WRASR function, we consider that users should bear > the consequences of rewriting registers during the debugging phase. In > fact, most of the time we rarely use WRASR, and only use it when we > are very confident. As I said, there should never never ever be a tool which allows writing of registers from userspace. If I could go back in time, I'd stop this on x86 but it is too late now. Not for ARM though. Also, do you see how all the people who replied to your mail, put the text under the quoted text. Do that too, pls, from now on, and refrain from top-posting. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette