diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index ca6ba3607705..90dbbd9666d4 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -87,9 +87,9 @@ int strcmp(const char *cs, const char *ct);
  *
  * Low level memory copy function that catches machine checks
  *
- * Return true for success, false for fail
+ * Return 0 for success, -EFAULT for fail
  */
-bool memcpy_mcsafe(void *dst, const void *src, size_t cnt);
+int memcpy_mcsafe(void *dst, const void *src, size_t cnt);
 
 #endif /* __KERNEL__ */
 
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index cbb8ee5830ff..2ec0b0abbfaa 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -1,6 +1,7 @@
 /* Copyright 2002 Andi Kleen */
 
 #include <linux/linkage.h>
+#include <asm/errno.h>
 #include <asm/cpufeatures.h>
 #include <asm/alternative-asm.h>
 
@@ -268,16 +269,16 @@ ENTRY(memcpy_mcsafe)
 	decl %ecx
 	jnz .L_copy_trailing_bytes
 
-	/* Copy successful. Return true */
+	/* Copy successful. Return zero */
 .L_done_memcpy_trap:
 	xorq %rax, %rax
 	ret
 ENDPROC(memcpy_mcsafe)
 
 	.section .fixup, "ax"
-	/* Return false for any failure */
+	/* Return -EFAULT for any failure */
 .L_memcpy_mcsafe_fail:
-	mov	$1, %rax
+	mov	$-EFAULT, %rax
 	ret
 
 	.previous