diff --git a/tools/virtio/linux/kernel.h b/tools/virtio/linux/kernel.h
index 395521a7a8d86b6cfe8510ac46fc6fee1b3fdb73..fca8381bbe041315d955f96e7e045d70d1cc89fb 100644
--- a/tools/virtio/linux/kernel.h
+++ b/tools/virtio/linux/kernel.h
@@ -118,7 +118,7 @@ static inline void free_page(unsigned long addr)
 #define dev_err(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 #define dev_warn(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 
-#define WARN_ON_ONCE(cond) ((cond) && fprintf (stderr, "WARNING\n"))
+#define WARN_ON_ONCE(cond) ((cond) ? fprintf (stderr, "WARNING\n") : 0)
 
 #define min(x, y) ({				\
 	typeof(x) _min1 = (x);			\
diff --git a/tools/virtio/linux/thread_info.h b/tools/virtio/linux/thread_info.h
new file mode 100644
index 0000000000000000000000000000000000000000..e0f610d08006c40e2f7500862202f66bb8e30291
--- /dev/null
+++ b/tools/virtio/linux/thread_info.h
@@ -0,0 +1 @@
+#define check_copy_size(A, B, C) (1)