v4.19.13 snapshot.
diff --git a/include/linux/timerfd.h b/include/linux/timerfd.h
new file mode 100644
index 0000000..0c33260
--- /dev/null
+++ b/include/linux/timerfd.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * include/linux/timerfd.h
+ *
+ * Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#ifndef _LINUX_TIMERFD_H
+#define _LINUX_TIMERFD_H
+
+#include <uapi/linux/timerfd.h>
+
+#define TFD_SHARED_FCNTL_FLAGS (TFD_CLOEXEC | TFD_NONBLOCK)
+/* Flags for timerfd_create. */
+#define TFD_CREATE_FLAGS TFD_SHARED_FCNTL_FLAGS
+/* Flags for timerfd_settime. */
+#define TFD_SETTIME_FLAGS (TFD_TIMER_ABSTIME | TFD_TIMER_CANCEL_ON_SET)
+
+#endif /* _LINUX_TIMERFD_H */