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

From: Ram Pai
Date: Sun Jul 16 2017 - 00:06:45 EST


arch_pkeys_enabled() returns true if the cpu
supports X86_FEATURE_OSPKE.

Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
---
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