s390/uaccess: fix access_ok compile warnings

On s390 access_ok is a macro which discards all parameters and always
returns 1. This can result in compile warnings which warn about unused
variables like this:

fs/read_write.c: In function 'rw_copy_check_uvector':
fs/read_write.c:684:16: warning: unused variable 'buf' [-Wunused-variable]

Fix this by adding a __range_ok() function which consumes all parameters
but still always returns 1.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 8e83da66df0d..1f3a79bcd262 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -50,10 +50,15 @@
 
 #define segment_eq(a,b) ((a).ar4 == (b).ar4)
 
-#define __access_ok(addr, size) \
-({                              \
-        __chk_user_ptr(addr);   \
-        1;                      \
+static inline int __range_ok(unsigned long addr, unsigned long size)
+{
+        return 1;
+}
+
+#define __access_ok(addr, size)                         \
+({                                                      \
+        __chk_user_ptr(addr);                           \
+        __range_ok((unsigned long)(addr), (size));      \
 })
 
 #define access_ok(type, addr, size) __access_ok(addr, size)