avr32: fix copy_from_user()

really ugly, but apparently avr32 compilers turns access_ok() into
something so bad that they want it in assembler.  Left that way,
zeroing added in inline wrapper.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 10 insertions, 1 deletions

diff --git a/arch/avr32/include/asm/uaccess.h b/arch/avr32/include/asm/uaccess.h
index 68cf638faf48..b1ec1fa06463 100644
--- a/arch/avr32/include/asm/uaccess.h
+++ b/arch/avr32/include/asm/uaccess.h
@@ -74,7 +74,7 @@ extern __kernel_size_t __copy_user(void *to, const void *from,
 
 extern __kernel_size_t copy_to_user(void __user *to, const void *from,
                                     __kernel_size_t n);
-extern __kernel_size_t copy_from_user(void *to, const void __user *from,
+extern __kernel_size_t ___copy_from_user(void *to, const void __user *from,
                                       __kernel_size_t n);
 
 static inline __kernel_size_t __copy_to_user(void __user *to, const void *from,
@@ -88,6 +88,15 @@ static inline __kernel_size_t __copy_from_user(void *to,
 {
         return __copy_user(to, (const void __force *)from, n);
 }
+static inline __kernel_size_t copy_from_user(void *to,
+                                               const void __user *from,
+                                               __kernel_size_t n)
+{
+        size_t res = ___copy_from_user(to, from, n);
+        if (unlikely(res))
+                memset(to + (n - res), 0, res);
+        return res;
+}
 
 #define __copy_to_user_inatomic __copy_to_user
 #define __copy_from_user_inatomic __copy_from_user