[PATCH 15/38] Annotate hardware config module parameters in drivers/mmc/host/

From	David Howells <dhowells@redhat.com>
Newsgroups	linux.kernel
Subject	[PATCH 15/38] Annotate hardware config module parameters in drivers/mmc/host/
Date	2017-04-05 19:20 +0200
Message-ID	<tsWL8-5w8-23@gated-at.bofh.it> (permalink)
References	<tsWBr-5sA-3@gated-at.bofh.it>
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

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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/mmc/host/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Pierre Ossman <pierre@ossman.eu>
cc: Ulf Hansson <ulf.hansson@linaro.org>
cc: linux-mmc@vger.kernel.org
---

 drivers/mmc/host/wbsd.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c
index bd04e8bae010..e15a9733fcfd 100644
--- a/drivers/mmc/host/wbsd.c
+++ b/drivers/mmc/host/wbsd.c
@@ -2001,11 +2001,11 @@ static void __exit wbsd_drv_exit(void)
 module_init(wbsd_drv_init);
 module_exit(wbsd_drv_exit);
 #ifdef CONFIG_PNP
-module_param_named(nopnp, param_nopnp, uint, 0444);
+module_param_hw_named(nopnp, param_nopnp, uint, other, 0444);
 #endif
-module_param_named(io, param_io, uint, 0444);
-module_param_named(irq, param_irq, uint, 0444);
-module_param_named(dma, param_dma, int, 0444);
+module_param_hw_named(io, param_io, uint, ioport, 0444);
+module_param_hw_named(irq, param_irq, uint, irq, 0444);
+module_param_hw_named(dma, param_dma, int, dma, 0444);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Pierre Ossman <pierre@ossman.eu>");

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[PATCH 15/38] Annotate hardware config module parameters in  drivers/mmc/host/ David Howells <dhowells@redhat.com> - 2017-04-05 19:20 +0200

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