microblaze: fix copy_from_user()
authorAl Viro <viro@zeniv.linux.org.uk>
Fri, 9 Sep 2016 23:22:34 +0000 (19:22 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Tue, 13 Sep 2016 21:50:17 +0000 (17:50 -0400)
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
arch/microblaze/include/asm/uaccess.h

index 331b0d35f89ce301ad9ba876be7322f417d7c909..3a486d3b6f52a1ddc089b26a1d59141e774a969d 100644 (file)
@@ -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)    \