diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h
index 23e77f5..9b43b49 100644
--- a/tools/testing/radix-tree/linux/kernel.h
+++ b/tools/testing/radix-tree/linux/kernel.h
@@ -8,6 +8,7 @@
 #include <limits.h>
 
 #include "../../include/linux/compiler.h"
+#include "../../include/linux/err.h"
 #include "../../../include/linux/kconfig.h"
 
 #ifdef BENCHMARK
@@ -58,4 +59,6 @@ static inline int in_interrupt(void)
 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
 #define round_down(x, y) ((x) & ~__round_mask(x, y))
 
+#define xchg(ptr, x)	uatomic_xchg(ptr, x)
+
 #endif /* _KERNEL_H */