2 files changed, 30 insertions, 0 deletions

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 0687c4748b8f..e997dcc6ee2b 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -99,6 +99,14 @@ static inline int pte_dirty(pte_t pte)
         return pte_flags(pte) & _PAGE_DIRTY;
 }
 
+
+static inline u32 read_pkru(void)
+{
+        if (boot_cpu_has(X86_FEATURE_OSPKE))
+                return __read_pkru();
+        return 0;
+}
+
 static inline int pte_young(pte_t pte)
 {
         return pte_flags(pte) & _PAGE_ACCESSED;
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 2270e41b32fd..aee6e76e561e 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -98,6 +98,28 @@ static inline void native_write_cr8(unsigned long val)
 }
 #endif
 
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+static inline u32 __read_pkru(void)
+{
+        u32 ecx = 0;
+        u32 edx, pkru;
+
+        /*
+         * "rdpkru" instruction.  Places PKRU contents in to EAX,
+         * clears EDX and requires that ecx=0.
+         */
+        asm volatile(".byte 0x0f,0x01,0xee\n\t"
+                     : "=a" (pkru), "=d" (edx)
+                     : "c" (ecx));
+        return pkru;
+}
+#else
+static inline u32 __read_pkru(void)
+{
+        return 0;
+}
+#endif
+
 static inline void native_wbinvd(void)
 {
         asm volatile("wbinvd": : :"memory");