[PATCH 32/47][X] Annotate hardware config module parameters in drivers/staging/media/

Seth Forshee seth.forshee at canonical.com
Thu Jun 18 23:12:43 UTC 2020


From: David Howells <dhowells at redhat.com>

BugLink: https://bugs.launchpad.net/bugs/1884159

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/staging/media/.

Suggested-by: Alan Cox <gnomes at lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells at redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Acked-by: Mauro Carvalho Chehab <mchehab at s-opensource.com>
cc: linux-media at vger.kernel.org
cc: devel at driverdev.osuosl.org
(cherry picked from commit 32820d8abd4d9502208697f0d26a3f8761b5868f)
Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
---
 drivers/staging/media/lirc/lirc_sir.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/media/lirc/lirc_sir.c b/drivers/staging/media/lirc/lirc_sir.c
index 4f326e97ad75..e27842e01fba 100644
--- a/drivers/staging/media/lirc/lirc_sir.c
+++ b/drivers/staging/media/lirc/lirc_sir.c
@@ -986,10 +986,10 @@ MODULE_AUTHOR("Milan Pikula");
 #endif
 MODULE_LICENSE("GPL");
 
-module_param(io, int, S_IRUGO);
+module_param_hw(io, int, ioport, S_IRUGO);
 MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
 
-module_param(irq, int, S_IRUGO);
+module_param_hw(irq, int, irq, S_IRUGO);
 MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
 
 module_param(threshold, int, S_IRUGO);
-- 
2.27.0




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