Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933184AbcLBMzV (ORCPT ); Fri, 2 Dec 2016 07:55:21 -0500 Received: from mail-qk0-f173.google.com ([209.85.220.173]:33559 "EHLO mail-qk0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932973AbcLBMzR (ORCPT ); Fri, 2 Dec 2016 07:55:17 -0500 MIME-Version: 1.0 In-Reply-To: <148059543997.31612.610019846448617763.stgit@warthog.procyon.org.uk> References: <148059537897.31612.9461043954611464597.stgit@warthog.procyon.org.uk> <148059543997.31612.610019846448617763.stgit@warthog.procyon.org.uk> From: Linus Walleij Date: Fri, 2 Dec 2016 13:55:16 +0100 Message-ID: Subject: Re: [PATCH 08/39] Annotate hardware config module parameters in drivers/gpio/ To: David Howells Cc: "linux-kernel@vger.kernel.org" , Alexandre Courbot , minyard@acm.org, One Thousand Gnomes , William Breathitt Gray , "linux-gpio@vger.kernel.org" , linux-security-module@vger.kernel.org, keyrings@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1528 Lines: 33 On Thu, Dec 1, 2016 at 1:30 PM, David Howells wrote: > 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/gpio/. > > Suggested-by: One Thousand Gnomes > Signed-off-by: David Howells > cc: William Breathitt Gray > cc: Linus Walleij > cc: Alexandre Courbot > cc: linux-gpio@vger.kernel.org Acked-by: Linus Walleij Yours, Linus Walleij