Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index e9de8ad..1fb11da 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 #ifndef _LINUX_TRACEPOINT_H
 #define _LINUX_TRACEPOINT_H
 
@@ -9,9 +10,6 @@
  * Copyright (C) 2008-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * Heavily inspired from the Linux Kernel Markers.
- *
- * This file is released under the GPLv2.
- * See the file COPYING for more details.
  */
 
 #include <linux/smp.h>
@@ -82,7 +80,7 @@
 static inline void tracepoint_synchronize_unregister(void)
 {
 	synchronize_srcu(&tracepoint_srcu);
-	synchronize_sched();
+	synchronize_rcu();
 }
 #else
 static inline void tracepoint_synchronize_unregister(void)
@@ -548,4 +546,19 @@
 
 #define TRACE_EVENT_PERF_PERM(event, expr...)
 
+#define DECLARE_EVENT_NOP(name, proto, args)				\
+	static inline void trace_##name(proto)				\
+	{ }								\
+	static inline bool trace_##name##_enabled(void)			\
+	{								\
+		return false;						\
+	}
+
+#define TRACE_EVENT_NOP(name, proto, args, struct, assign, print)	\
+	DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
+
+#define DECLARE_EVENT_CLASS_NOP(name, proto, args, tstruct, assign, print)
+#define DEFINE_EVENT_NOP(template, name, proto, args)			\
+	DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
+
 #endif /* ifdef TRACE_EVENT (see note above) */