Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932993AbdDERVS (ORCPT ); Wed, 5 Apr 2017 13:21:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54638 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754846AbdDEQ5u (ORCPT ); Wed, 5 Apr 2017 12:57:50 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com AC0FBC04BD24 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dhowells@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com AC0FBC04BD24 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 07/38] Annotate hardware config module parameters in drivers/cpufreq/ From: David Howells To: linux-kernel@vger.kernel.org Cc: gnomes@lxorguk.ukuu.org.uk, linux-pm@vger.kernel.org, Viresh Kumar , "Rafael J. Wysocki" , dhowells@redhat.com, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, gregkh@linuxfoundation.org Date: Wed, 05 Apr 2017 17:57:47 +0100 Message-ID: <149141146722.29162.13947802705058712127.stgit@warthog.procyon.org.uk> In-Reply-To: <149141141298.29162.5612793122429261720.stgit@warthog.procyon.org.uk> References: <149141141298.29162.5612793122429261720.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 05 Apr 2017 16:57:49 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1836 Lines: 43 When the kernel is running in secure boot mode, we lock down the kernel to prevent userspace from modifying the running kernel image. Whilst this includes prohibiting access to things like /dev/mem, it must also prevent access by means of configuring driver modules in such a way as to cause a device to access or modify the kernel image. To this end, annotate module_param* statements that refer to hardware configuration and indicate for future reference what type of parameter they specify. The parameter parser in the core sees this information and can skip such parameters with an error message if the kernel is locked down. The module initialisation then runs as normal, but just sees whatever the default values for those parameters is. Note that we do still need to do the module initialisation because some drivers have viable defaults set in case parameters aren't specified and some drivers support automatic configuration (e.g. PNP or PCI) in addition to manually coded parameters. This patch annotates drivers in drivers/cpufreq/. Suggested-by: Alan Cox Signed-off-by: David Howells Acked-by: "Rafael J. Wysocki" cc: Viresh Kumar cc: linux-pm@vger.kernel.org --- drivers/cpufreq/speedstep-smi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cpufreq/speedstep-smi.c b/drivers/cpufreq/speedstep-smi.c index 770a9ae1999a..37b30071c220 100644 --- a/drivers/cpufreq/speedstep-smi.c +++ b/drivers/cpufreq/speedstep-smi.c @@ -378,7 +378,7 @@ static void __exit speedstep_exit(void) cpufreq_unregister_driver(&speedstep_driver); } -module_param(smi_port, int, 0444); +module_param_hw(smi_port, int, ioport, 0444); module_param(smi_cmd, int, 0444); module_param(smi_sig, uint, 0444);