Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753535AbcLGSfC (ORCPT ); Wed, 7 Dec 2016 13:35:02 -0500 Received: from mail.kernel.org ([198.145.29.136]:46816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753222AbcLGSfA (ORCPT ); Wed, 7 Dec 2016 13:35:00 -0500 Date: Wed, 7 Dec 2016 12:34:55 -0600 From: Bjorn Helgaas To: David Howells Cc: linux-kernel@vger.kernel.org, Scott Murray , minyard@acm.org, gnomes@lxorguk.ukuu.org.uk, linux-pci@vger.kernel.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, Bjorn Helgaas Subject: Re: [PATCH 25/39] Annotate hardware config module parameters in drivers/pci/hotplug/ Message-ID: <20161207183455.GC22129@bhelgaas-glaptop.roam.corp.google.com> References: <148059537897.31612.9461043954611464597.stgit@warthog.procyon.org.uk> <148059557836.31612.5039521915534964791.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <148059557836.31612.5039521915534964791.stgit@warthog.procyon.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2522 Lines: 55 On Thu, Dec 01, 2016 at 12:32:58PM +0000, 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/pci/hotplug/. > > Suggested-by: One Thousand Gnomes > Signed-off-by: David Howells > cc: Scott Murray > cc: Bjorn Helgaas > cc: linux-pci@vger.kernel.org Acked-by: Bjorn Helgaas I assume you'll merge this via some non-PCI tree. Let me know if you need anything else from me. > --- > > drivers/pci/hotplug/cpcihp_generic.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/hotplug/cpcihp_generic.c b/drivers/pci/hotplug/cpcihp_generic.c > index 88a44a707b96..bbf9cf8aeaad 100644 > --- a/drivers/pci/hotplug/cpcihp_generic.c > +++ b/drivers/pci/hotplug/cpcihp_generic.c > @@ -220,7 +220,7 @@ module_param(first_slot, byte, 0); > MODULE_PARM_DESC(first_slot, "Hotswap bus first slot number"); > module_param(last_slot, byte, 0); > MODULE_PARM_DESC(last_slot, "Hotswap bus last slot number"); > -module_param(port, ushort, 0); > +module_param_hw(port, ushort, ioport, 0); > MODULE_PARM_DESC(port, "#ENUM signal I/O port"); > module_param(enum_bit, uint, 0); > MODULE_PARM_DESC(enum_bit, "#ENUM signal bit (0-7)"); > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html