microblaze: fix copy_from_user()

[firefly-linux-kernel-4.4.55.git] / arch / microblaze / include / asm / uaccess.h

diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index 905a9c67f6b89480a94085985d3466589e8ff0b4..826676778094f23a8ced8264b5c448184c0fa006 100644 (file)
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -373,10 +373,13 @@ extern long __user_bad(void);
 static inline long copy_from_user(void *to,
                const void __user *from, unsigned long n)
 {
+       unsigned long res = n;
        might_fault();
-       if (access_ok(VERIFY_READ, from, n))
-               return __copy_from_user(to, from, n);
-       return n;
+       if (likely(access_ok(VERIFY_READ, from, n)))
+               res = __copy_from_user(to, from, n);
+       if (unlikely(res))
+               memset(to + (n - res), 0, res);
+       return res;
 }
 
 #define __copy_to_user(to, from, n)    \