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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 77550C64E7B for ; Mon, 30 Nov 2020 18:07:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3114D2067C for ; Mon, 30 Nov 2020 18:07:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="UaDyV4fD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729536AbgK3SGf (ORCPT ); Mon, 30 Nov 2020 13:06:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:53478 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728512AbgK3SGe (ORCPT ); Mon, 30 Nov 2020 13:06:34 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 5CE67206F9; Mon, 30 Nov 2020 18:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606759553; bh=LEf4/GBSUYi7Yxi/3jEzeug3u/5guDqeKo5QtUgX5Zg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=UaDyV4fDfovSb5djP8oXgSWijVIa5cTZ2WVLoOCv0Djh+GjSJ+hv0t14d7H7Y84jN fPokKr9+9sRZBny9lPeTiZXhFuh38GE9qYbkLuqnDWO+td2WaFdth/diOn7pkRrTvE /1Vi6Dk6sqIb8ztmoTT9GFddL1CuHFooHHBdt2Xs= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1kjnYd-00Em4N-Ff; Mon, 30 Nov 2020 18:05:51 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 30 Nov 2020 18:05:51 +0000 From: Marc Zyngier To: Rongwei Wang Cc: catalin.marinas@arm.com, will@kernel.org, bjorn.andersson@linaro.org, shawnguo@kernel.org, gshan@redhat.com, geert+renesas@glider.be, Anson.Huang@nxp.com, masahiroy@kernel.org, michael@walle.cc, krzk@kernel.org, linux-kernel@vger.kernel.org, vkoul@kernel.org, olof@lixom.net, vincenzo.frascino@arm.com, ardb@kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 0/3] arm64:msr: Add MSR driver In-Reply-To: <20201130174833.41315-1-rongwei.wang@linux.alibaba.com> References: <20201130174833.41315-1-rongwei.wang@linux.alibaba.com> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <5e7f7225982b2df63e62ea60ec632376@misterjones.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: rongwei.wang@linux.alibaba.com, catalin.marinas@arm.com, will@kernel.org, bjorn.andersson@linaro.org, shawnguo@kernel.org, gshan@redhat.com, geert+renesas@glider.be, Anson.Huang@nxp.com, masahiroy@kernel.org, michael@walle.cc, krzk@kernel.org, linux-kernel@vger.kernel.org, vkoul@kernel.org, olof@lixom.net, vincenzo.frascino@arm.com, ardb@kernel.org, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-11-30 17:48, Rongwei Wang wrote: > The interfaces of this module is same as MSR module in user space, and > to solve > the problem that ARM platform has no similar MSR module. Using this > interface, > we did some pressure tests to test the stability and security of MSR > driver. The > test results show that the driver will not cause system panic if > various > illegal values and multithreading concurrent access are passed through > the > interface. It would certainly help if you described what problem you are trying to solve here. In general, giving userspace access to random system registers is a pretty bad idea. Are you trying to validate a CPU? a hypervisor? Or is it just a fun way to check how many things you can poke before something catches fire? Thanks, M. -- Jazz is not dead. It just smells funny...