diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index e0e71ca023ce34ea501dcf0617bac19cea13fa1a..403ba3eb4b8443071a30b1ce32f2fbe04412e722 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -225,6 +225,7 @@ EXPORT_SYMBOL(copy_user_enhanced_fast_string)
  * Don't try to copy the tail if machine check happened
  *
  * Input:
+ * eax trap number written by ex_handler_copy()
  * rdi destination
  * rsi source
  * rdx count
@@ -233,12 +234,20 @@ EXPORT_SYMBOL(copy_user_enhanced_fast_string)
  * eax uncopied bytes or 0 if successful.
  */
 SYM_CODE_START_LOCAL(.Lcopy_user_handle_tail)
+	cmp $X86_TRAP_MC,%eax
+	je 3f
+
 	movl %edx,%ecx
 1:	rep movsb
 2:	mov %ecx,%eax
 	ASM_CLAC
 	ret
 
+3:
+	movl %edx,%eax
+	ASM_CLAC
+	RET
+
 	_ASM_EXTABLE_CPY(1b, 2b)
 SYM_CODE_END(.Lcopy_user_handle_tail)