With /sys/kernel/debug/acpi/custom_method root can write
to arbitrary memory and increase his priveleges, even if
these are restricted.
-> Make this an own debug .config option and warn about the
security issue in the config description.
-> Still keep acpi/debugfs.c which now only creates an empty
/sys/kernel/debug/acpi directory. There might be other
users of it later.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: rui.zhang@intel.com
Signed-off-by: Len Brown <len.brown@intel.com>
Introduce module parameter acpi.aml_debug_output.
With acpi.aml_debug_output set, we can get AML debug object output
(Store (AAA, Debug)), even with CONFIG_ACPI_DEBUG cleared.
Together with the runtime custom method mechanism,
we can debug AML code problems without rebuilding the kernel.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Introduce a new debugfs I/F (/sys/kernel/debug/acpi/custom_method) for ACPI,
which can be used to customize the ACPI control methods at runtime.
We can use this to debug the AML code level bugs instead of overriding the
whole DSDT table, without rebuilding/rebooting kernel any more.
Detailed description about how to use this debugfs I/F is stated in
Documentation/acpi/method-customizing.txt
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Thomas Renninger