Index: head/sys/compat/linuxkpi/common/include/asm/uaccess.h
===================================================================
--- head/sys/compat/linuxkpi/common/include/asm/uaccess.h	(revision 347619)
+++ head/sys/compat/linuxkpi/common/include/asm/uaccess.h	(revision 347620)
@@ -1,68 +1,72 @@
 /*-
  * Copyright (c) 2010 Isilon Systems, Inc.
  * Copyright (c) 2010 iX Systems, Inc.
  * Copyright (c) 2010 Panasas, Inc.
  * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice unmodified, this list of conditions, and the following
  *    disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * $FreeBSD$
  */
 #ifndef _ASM_UACCESS_H_
 #define _ASM_UACCESS_H_
 
 #include <linux/uaccess.h>
 
 static inline long
 copy_to_user(void *to, const void *from, unsigned long n)
 {
 	if (linux_copyout(from, to, n) != 0)
 		return n;
 	return 0;
 }
 #define	__copy_to_user(...)	copy_to_user(__VA_ARGS__)
 
 static inline long
 copy_from_user(void *to, const void *from, unsigned long n)
 {
 	if (linux_copyin(from, to, n) != 0)
 		return n;
 	return 0;
 }
 #define	__copy_from_user(...)	copy_from_user(__VA_ARGS__)
 #define	__copy_in_user(...)	copy_from_user(__VA_ARGS__)
 
+#if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 50000
+#define	user_access_begin(ptr, len) access_ok(ptr, len)
+#else
 #define	user_access_begin() do { } while (0)
+#endif
 #define	user_access_end() do { } while (0)
 
 #define	unsafe_get_user(x, ptr, err) do { \
 	if (unlikely(__get_user(x, ptr))) \
 		goto err; \
 } while (0)
 
 #define	unsafe_put_user(x, ptr, err) do { \
 	if (unlikely(__put_user(x, ptr))) \
 		goto err; \
 } while (0)
 
 #endif	/* _ASM_UACCESS_H_ */