52 lines
2.2 KiB
Diff
52 lines
2.2 KiB
Diff
From: David Howells <dhowells@redhat.com>
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Date: Tue, 4 Apr 2017 16:54:21 +0100
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Subject: [02/62] Annotate hardware config module parameters in arch/x86/mm/
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Origin: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit?id=89a35b5df5de26b9eaed0791580cea872232d563
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When the kernel is running in secure boot mode, we lock down the kernel to
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prevent userspace from modifying the running kernel image. Whilst this
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includes prohibiting access to things like /dev/mem, it must also prevent
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access by means of configuring driver modules in such a way as to cause a
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device to access or modify the kernel image.
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To this end, annotate module_param* statements that refer to hardware
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configuration and indicate for future reference what type of parameter they
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specify. The parameter parser in the core sees this information and can
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skip such parameters with an error message if the kernel is locked down.
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The module initialisation then runs as normal, but just sees whatever the
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default values for those parameters is.
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Note that we do still need to do the module initialisation because some
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drivers have viable defaults set in case parameters aren't specified and
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some drivers support automatic configuration (e.g. PNP or PCI) in addition
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to manually coded parameters.
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This patch annotates drivers in arch/x86/mm/.
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Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
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Signed-off-by: David Howells <dhowells@redhat.com>
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cc: Steven Rostedt <rostedt@goodmis.org>
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cc: Ingo Molnar <mingo@kernel.org>
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cc: Thomas Gleixner <tglx@linutronix.de>
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cc: "H. Peter Anvin" <hpa@zytor.com>
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cc: x86@kernel.org
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cc: linux-kernel@vger.kernel.org
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cc: nouveau@lists.freedesktop.org
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---
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arch/x86/mm/testmmiotrace.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c
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index 38868adf07ea..f6ae6830b341 100644
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--- a/arch/x86/mm/testmmiotrace.c
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+++ b/arch/x86/mm/testmmiotrace.c
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@@ -9,7 +9,7 @@
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#include <linux/mmiotrace.h>
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static unsigned long mmio_address;
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-module_param(mmio_address, ulong, 0);
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+module_param_hw(mmio_address, ulong, iomem, 0);
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MODULE_PARM_DESC(mmio_address, " Start address of the mapping of 16 kB "
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"(or 8 MB if read_far is non-zero).");
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