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-rw-r--r--arch/x86/include/asm/pgtable.h8
-rw-r--r--arch/x86/include/asm/special_insns.h22
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");