x86/mm/pkeys: Add Kconfig prompt to existing config option

I don't have a strong opinion on whether we need this 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.

Here's the option if folks want it.

Signed-off-by: Dave Hansen <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fb2ebeb9a6925ff5a2bf0e2395602f0ff0f8dc35..b8754348de4dbe1e8c9ce957ba557ff6ac9690a1 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1716,8 +1716,18 @@ config X86_INTEL_MPX
          If unsure, say N.
 
 config X86_INTEL_MEMORY_PROTECTION_KEYS
+       prompt "Intel Memory Protection Keys"
        def_bool y
+       # Note: only available in 64-bit mode
        depends on CPU_SUP_INTEL && X86_64
+       ---help---
+         Memory Protection Keys provides a mechanism for enforcing
+         page-based protections, but without requiring modification of the
+         page tables when an application changes protection domains.
+
+         For details, see Documentation/x86/protection-keys.txt
+
+         If unsure, say y.
 
 config EFI
        bool "EFI runtime service support"