Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/testing/selftests/kselftest_module.sh b/tools/testing/selftests/kselftest_module.sh
new file mode 100755
index 0000000..18e1c79
--- /dev/null
+++ b/tools/testing/selftests/kselftest_module.sh
@@ -0,0 +1,84 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+
+#
+# Runs an individual test module.
+#
+# kselftest expects a separate executable for each test, this can be
+# created by adding a script like this:
+#
+#   #!/bin/sh
+#   SPDX-License-Identifier: GPL-2.0+
+#   $(dirname $0)/../kselftest_module.sh "description" module_name
+#
+# Example: tools/testing/selftests/lib/printf.sh
+
+desc=""				# Output prefix.
+module=""			# Filename (without the .ko).
+args=""				# modprobe arguments.
+
+modprobe="/sbin/modprobe"
+
+main() {
+    parse_args "$@"
+    assert_root
+    assert_have_module
+    run_module
+}
+
+parse_args() {
+    script=${0##*/}
+
+    if [ $# -lt 2 ]; then
+	echo "Usage: $script <description> <module_name> [FAIL]"
+	exit 1
+    fi
+
+    desc="$1"
+    shift || true
+    module="$1"
+    shift || true
+    args="$@"
+}
+
+assert_root() {
+    if [ ! -w /dev ]; then
+	skip "please run as root"
+    fi
+}
+
+assert_have_module() {
+    if ! $modprobe -q -n $module; then
+	skip "module $module is not found"
+    fi
+}
+
+run_module() {
+    if $modprobe -q $module $args; then
+	$modprobe -q -r $module
+	say "ok"
+    else
+	fail ""
+    fi
+}
+
+say() {
+    echo "$desc: $1"
+}
+
+
+fail() {
+    say "$1 [FAIL]" >&2
+    exit 1
+}
+
+skip() {
+    say "$1 [SKIP]" >&2
+    # Kselftest framework requirement - SKIP code is 4.
+    exit 4
+}
+
+#
+# Main script
+#
+main "$@"