diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 4fc5c2de2de4..01c5de4c279b 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -7,6 +7,8 @@
  */
 
 #include <linux/linkage.h>
+#include <asm/cpufeatures.h>
+#include <asm/alternative.h>
 #include <asm/asm.h>
 #include <asm/export.h>
 
@@ -29,7 +31,7 @@
  */
 SYM_FUNC_START(rep_movs_alternative)
 	cmpq $64,%rcx
-	jae .Lunrolled
+	jae .Llarge
 
 	cmp $8,%ecx
 	jae .Lword
@@ -65,6 +67,12 @@ SYM_FUNC_START(rep_movs_alternative)
 	_ASM_EXTABLE_UA( 2b, .Lcopy_user_tail)
 	_ASM_EXTABLE_UA( 3b, .Lcopy_user_tail)
 
+.Llarge:
+0:	ALTERNATIVE "jmp .Lunrolled", "rep movsb", X86_FEATURE_ERMS
+1:	RET
+
+        _ASM_EXTABLE_UA( 0b, 1b)
+
 	.p2align 4
 .Lunrolled:
 10:	movq (%rsi),%r8