Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/perf/lib/tests/test-cpumap.c b/tools/perf/lib/tests/test-cpumap.c
new file mode 100644
index 0000000..aa34c20
--- /dev/null
+++ b/tools/perf/lib/tests/test-cpumap.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdarg.h>
+#include <stdio.h>
+#include <perf/cpumap.h>
+#include <internal/tests.h>
+
+static int libperf_print(enum libperf_print_level level,
+			 const char *fmt, va_list ap)
+{
+	return vfprintf(stderr, fmt, ap);
+}
+
+int main(int argc, char **argv)
+{
+	struct perf_cpu_map *cpus;
+
+	__T_START;
+
+	libperf_init(libperf_print);
+
+	cpus = perf_cpu_map__dummy_new();
+	if (!cpus)
+		return -1;
+
+	perf_cpu_map__get(cpus);
+	perf_cpu_map__put(cpus);
+	perf_cpu_map__put(cpus);
+
+	__T_OK;
+	return 0;
+}