[PATCH 05/33] x86, pkeys: Add Kconfig option

From: Dave Hansen
Date: Fri Feb 12 2016 - 16:12:04 EST



From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>

I don't have a strong opinion on whether we need a Kconfig prompt
or not. Protection Keys has relatively little code associated
with it, and it is not a heavyweight feature to keep enabled.
However, I can imagine that folks would still appreciate being
able to disable it.

Note that, with disabled-features.h, the checks in the code
for protection keys are always the same:

cpu_has(c, X86_FEATURE_PKU)

With the config option disabled, this essentially turns into an
#ifdef.

We will hide the prompt for now.

Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---

b/arch/x86/Kconfig | 4 ++++
1 file changed, 4 insertions(+)

diff -puN arch/x86/Kconfig~pkeys-01-kconfig arch/x86/Kconfig
--- a/arch/x86/Kconfig~pkeys-01-kconfig 2016-02-12 10:44:15.909231872 -0800
+++ b/arch/x86/Kconfig 2016-02-12 10:44:15.913232055 -0800
@@ -1713,6 +1713,10 @@ config X86_INTEL_MPX

If unsure, say N.

+config X86_INTEL_MEMORY_PROTECTION_KEYS
+ def_bool y
+ depends on CPU_SUP_INTEL && X86_64
+
config EFI
bool "EFI runtime service support"
depends on ACPI
_