MIPS: Make access_ok() sideeffect proof.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 13 insertions, 3 deletions

diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index 09ff5bb17445..42b9cec2ee96 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -104,11 +104,21 @@
 
 #define __access_mask get_fs().seg
 
-#define __access_ok(addr, size, mask)                                   \
-        (((signed long)((mask) & ((addr) | ((addr) + (size)) | __ua_size(size)))) == 0)
+#define __access_ok(addr, size, mask)                                                   \
+({                                                                                      \
+        const volatile void __user *__up = addr;                                        \
+        unsigned long __addr = (unsigned long) __up;                                    \
+        unsigned long __size = size;                                                    \
+        unsigned long __mask = mask;                                                    \
+        unsigned long __ok;                                                             \
+                                                                                        \
+        __ok = (signed long)(__mask & (__addr | (__addr + __size) |                     \
+                __ua_size(__size)));                                                    \
+        __ok == 0;                                                                      \
+})
 
 #define access_ok(type, addr, size)                                     \
-        likely(__access_ok((unsigned long)(addr), (size), __access_mask))
+        likely(__access_ok((addr), (size), __access_mask))
 
 /*
  * put_user: - Write a simple value into user space.