ia64: copy_from_user() should zero the destination on access_ok() failure

commit a5e541f796f17228793694d64b507f5f57db4cd7 upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: no calls to check_object_size()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/arch/ia64/include/asm/uaccess.h b/arch/ia64/include/asm/uaccess.h
index 449c8c0..810926c 100644 (file)
--- a/arch/ia64/include/asm/uaccess.h
+++ b/arch/ia64/include/asm/uaccess.h
@@ -262,17 +262,15 @@ __copy_from_user (void *to, const void __user *from, unsigned long count)
        __cu_len;                                                                       \
 })
 
        __cu_len;                                                                       \
 })
 

-#define copy_from_user(to, from, n)                                                    \
-({                                                                                     \
-       void *__cu_to = (to);                                                           \
-       const void __user *__cu_from = (from);                                          \
-       long __cu_len = (n);                                                            \
-                                                                                       \
-       __chk_user_ptr(__cu_from);                                                      \
-       if (__access_ok(__cu_from, __cu_len, get_fs()))                                 \
-               __cu_len = __copy_user((__force void __user *) __cu_to, __cu_from, __cu_len);   \
-       __cu_len;                                                                       \
-})
+static inline unsigned long
+copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+       if (likely(__access_ok(from, n, get_fs())))
+               n = __copy_user((__force void __user *) to, from, n);
+       else
+               memset(to, 0, n);
+       return n;
+}

 
 #define __copy_in_user(to, from, size) __copy_user((to), (from), (size))
 
 
 #define __copy_in_user(to, from, size) __copy_user((to), (from), (size))