[PATCH 03/31] x86, pkeys: Add Kconfig option

[Dave Hansen]

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	2016-01-28 15:52:17.645279448 -0800
+++ b/arch/x86/Kconfig	2016-01-28 15:52:17.649279631 -0800
@@ -1714,6 +1714,10 @@ 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
_