From: Dave Hansen <dave.hansen@linux.intel.com>
Date: Fri, 12 Feb 2016 21:02:00 +0000 (-0800)
Subject: x86/mm/pkeys: Add Kconfig option
X-Git-Tag: v4.6-rc1~68^2~33
X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=35e97790f5f1e5cf2b5522c55e3e31d5c81bd226

x86/mm/pkeys: Add Kconfig option

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

We will hide the prompt for now.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210200.DB7055E8@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ab2ed5328f0a..3632cdd03201 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -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