Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933507AbdDERf5 (ORCPT ); Wed, 5 Apr 2017 13:35:57 -0400 Received: from mail.kernel.org ([198.145.29.136]:32808 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933375AbdDERfm (ORCPT ); Wed, 5 Apr 2017 13:35:42 -0400 Date: Wed, 5 Apr 2017 13:35:37 -0400 From: Steven Rostedt To: David Howells Cc: linux-kernel@vger.kernel.org, gnomes@lxorguk.ukuu.org.uk, gregkh@linuxfoundation.org, nouveau@lists.freedesktop.org, x86@kernel.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar Subject: Re: [PATCH 02/38] Annotate hardware config module parameters in arch/x86/mm/ Message-ID: <20170405133537.3a1fdb5b@gandalf.local.home> In-Reply-To: <149141142839.29162.10470212173396183651.stgit@warthog.procyon.org.uk> References: <149141141298.29162.5612793122429261720.stgit@warthog.procyon.org.uk> <149141142839.29162.10470212173396183651.stgit@warthog.procyon.org.uk> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2150 Lines: 54 On Wed, 05 Apr 2017 17:57:08 +0100 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 arch/x86/mm/. > > Suggested-by: Alan Cox > Signed-off-by: David Howells Acked-by: Steven Rostedt (VMware) -- Steve > cc: Ingo Molnar > cc: Thomas Gleixner > cc: "H. Peter Anvin" > cc: x86@kernel.org > cc: linux-kernel@vger.kernel.org > cc: nouveau@lists.freedesktop.org > --- > > arch/x86/mm/testmmiotrace.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c > index 38868adf07ea..f6ae6830b341 100644 > --- a/arch/x86/mm/testmmiotrace.c > +++ b/arch/x86/mm/testmmiotrace.c > @@ -9,7 +9,7 @@ > #include > > static unsigned long mmio_address; > -module_param(mmio_address, ulong, 0); > +module_param_hw(mmio_address, ulong, iomem, 0); > MODULE_PARM_DESC(mmio_address, " Start address of the mapping of 16 kB " > "(or 8 MB if read_far is non-zero)."); >