h8300: fix recent uaccess breakage

Al Viro wrote:
>
> 	After that commit in asm-h8300/uaccess.h we have
>
> #define get_user(x, ptr)                                        \
> ({                                                              \
>     int __gu_err = 0;                                           \
>     uint32_t __gu_val = 0;                              \
>     ^^^^^^^^^^^^^^^^^
>     switch (sizeof(*(ptr))) {                                   \
>     case 1:                                                     \
>     case 2:                                                     \
>     case 4:                                                     \
>         __gu_val = *(ptr);                                      \
>         break;                                                  \
>     case 8:                                                     \
>         memcpy(&__gu_val, ptr, sizeof (*(ptr)));                \
>                                ^^^^^^^^^^^^^^^^
>
> which, of course, is FUBAR whenever we actually hit that case - memcpy of
> 8 bytes into uint32_t is obviously wrong.  Why don't we simply do

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NYoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/asm-h8300/uaccess.h

@@ -91,22 +91,19 @@ extern int __put_user_bad(void);
 #define get_user(x, ptr)					\
 ({								\
     int __gu_err = 0;						\
-    uint32_t __gu_val = 0;				\
+    typeof(*(ptr)) __gu_val = *ptr;				\
     switch (sizeof(*(ptr))) {					\
     case 1:							\
     case 2:							\
     case 4:							\
-	__gu_val = *(ptr);	                		\
-	break;							\
-    case 8:							\
-	memcpy(&__gu_val, ptr, sizeof (*(ptr))); 		\
+    case 8: 							\
 	break;							\
     default:							\
-	__gu_val = 0;						\
 	__gu_err = __get_user_bad();				\
+	__gu_val = 0;						\
 	break;							\
     }								\
-    (x) = (typeof(*(ptr)))__gu_val;				\
+    (x) = __gu_val;						\
     __gu_err;							\
 })
 #define __get_user(x, ptr) get_user(x, ptr)