x86: don't always use EFAULT on __get_user_size.

Let the user of the macro specify the desired return.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/asm-x86/uaccess_64.h

@@ -61,27 +61,27 @@ extern void __put_user_bad(void);
 ({								\
 	int __gu_err;						\
 	unsigned long __gu_val;					\
-	__get_user_size(__gu_val, (ptr), (size), __gu_err);	\
+	__get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT);\
 	(x) = (__force typeof(*(ptr)))__gu_val;			\
 	__gu_err;						\
 })
 
-#define __get_user_size(x, ptr, size, retval)				\
+#define __get_user_size(x, ptr, size, retval, errret)			\
 do {									\
 	retval = 0;							\
 	__chk_user_ptr(ptr);						\
 	switch (size) {							\
 	case 1:								\
-		__get_user_asm(x, ptr, retval, "b", "b", "=q", -EFAULT);\
+		__get_user_asm(x, ptr, retval, "b", "b", "=q", errret);\
 		break;							\
 	case 2:								\
-		__get_user_asm(x, ptr, retval, "w", "w", "=r", -EFAULT);\
+		__get_user_asm(x, ptr, retval, "w", "w", "=r", errret);\
 		break;							\
 	case 4:								\
-		__get_user_asm(x, ptr, retval, "l", "k", "=r", -EFAULT);\
+		__get_user_asm(x, ptr, retval, "l", "k", "=r", errret);\
 		break;							\
 	case 8:								\
-		__get_user_asm(x, ptr, retval, "q", "", "=r", -EFAULT);	\
+		__get_user_asm(x, ptr, retval, "q", "", "=r", errret);	\
 		break;							\
 	default:							\
 		(x) = __get_user_bad();					\