# \[PATCH 6/9\] ARM: uaccess: avoid warning for NOMMU in access\_ok

- From: Arnd Bergmann \<arnd@arndb.de\>
- Date: 2016-02-18 14:04:52 
- List: linux-arm-kernel
- Page: https://ratatoskr.run/linux-arm-kernel/2016/02/4688539
- Thread: https://ratatoskr.run/linux-arm-kernel/2016/02/8730107/t.md

```text
When CONFIG_MMU is disabled, the access_ok() and __range_ok()
macros always return success, and there is a cast to void
to ensure the compiler does not warn about an unused address
variable. However, at least one driver has a variable for
the size argument as well and does warn about that one:

drivers/vhost/vhost.c: In function 'vq_access_ok':
drivers/vhost/vhost.c:633:9: warning: unused variable 's' [-Wunused-variable]

This changes the macro to also ignore the size argument
explicitly to shut up that warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/include/asm/uaccess.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 35c9db857ebe..9c74c84a10d2 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -290,7 +290,7 @@ extern int __put_user_8(void *, unsigned long long);
 
 #define segment_eq(a, b)		(1)
 #define __addr_ok(addr)		((void)(addr), 1)
-#define __range_ok(addr, size)	((void)(addr), 0)
+#define __range_ok(addr, size)	((void)(addr), (void)(size), 0)
 #define get_fs()		(KERNEL_DS)
 
 static inline void set_fs(mm_segment_t fs)
-- 
2.7.0
```
