Subject: [RFC v6 37/62] x86: implementation for arch_pkeys_enabled()

From: Ram Pai <[email-masked]>
Date: Sat, 15 Jul 2017 20:56:39 -0700

arch_pkeys_enabled() returns true if the cpu
supports X86_FEATURE_OSPKE.

Signed-off-by: Ram Pai <[email-masked]>
---
 arch/x86/include/asm/pkeys.h |    1 +
 arch/x86/kernel/fpu/xstate.c |    5 +++++
 2 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h
index b3b09b9..fa82799 100644
--- a/arch/x86/include/asm/pkeys.h
+++ b/arch/x86/include/asm/pkeys.h
@@ -5,6 +5,7 @@
 
 extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 		unsigned long init_val);
+extern bool arch_pkeys_enabled(void);
 
 /*
  * Try to dedicate one of the protection keys to be used as an
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c24ac1e..df594b8 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -918,6 +918,11 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 
 	return 0;
 }
+
+bool arch_pkeys_enabled(void)
+{
+	return boot_cpu_has(X86_FEATURE_OSPKE);
+}
 #endif /* ! CONFIG_ARCH_HAS_PKEYS */
 
 /*
-- 
1.7.1