1 files changed, 101 insertions, 0 deletions
diff --git a/tools/testing/selftests/ftrace/test.d/00basic/mount_options.tc b/tools/testing/selftests/ftrace/test.d/00basic/mount_options.tc
new file mode 100644
index 000000000000..35e8d47d6072
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/00basic/mount_options.tc
@@ -0,0 +1,101 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Test tracefs GID mount option
+# requires: "[gid=<gid>]":README
+
+fail() {
+	local msg="$1"
+
+	echo "FAILED: $msg"
+	exit_fail
+}
+
+find_alternate_gid() {
+	local original_gid="$1"
+	tac /etc/group | grep -v ":$original_gid:" | head -1 | cut -d: -f3
+}
+
+mount_tracefs_with_options() {
+	local mount_point="$1"
+	local options="$2"
+
+	mount -t tracefs -o "$options" nodev "$mount_point"
+
+	setup
+}
+
+unmount_tracefs() {
+	local mount_point="$1"
+
+	# Need to make sure the mount isn't busy so that we can umount it
+	(cd $mount_point; finish_ftrace;)
+
+	cleanup
+}
+
+create_instance() {
+	local mount_point="$1"
+	local instance="$mount_point/instances/$(mktemp -u test-XXXXXX)"
+
+	mkdir "$instance"
+	echo "$instance"
+}
+
+remove_instance() {
+	local instance="$1"
+
+	rmdir "$instance"
+}
+
+check_gid() {
+	local mount_point="$1"
+	local expected_gid="$2"
+
+	echo "Checking permission group ..."
+
+	cd "$mount_point"
+
+	for file in "." "events" "events/sched" "events/sched/sched_switch" "events/sched/sched_switch/enable"; do
+		local gid=`stat -c "%g" $file`
+		if [ "$gid" -ne "$expected_gid" ]; then
+			cd - # Return to the previous working directory (tracefs root)
+			fail "$(realpath $file): Expected group $expected_gid; Got group $gid"
+		fi
+	done
+
+	cd - # Return to the previous working directory (tracefs root)
+}
+
+test_gid_mount_option() {
+	local mount_point=$(get_mount_point)
+	local mount_options=$(get_mnt_options "$mount_point")
+	local original_group=$(stat -c "%g" .)
+	local other_group=$(find_alternate_gid "$original_group")
+
+	# Set up mount options with new GID for testing
+	local new_options=`echo "$mount_options" | sed -e "s/gid=[0-9]*/gid=$other_group/"`
+	if [ "$new_options" = "$mount_options" ]; then
+		new_options="$mount_options,gid=$other_group"
+		mount_options="$mount_options,gid=$original_group"
+	fi
+
+	# Unmount existing tracefs instance and mount with new GID
+	unmount_tracefs "$mount_point"
+	mount_tracefs_with_options "$mount_point" "$new_options"
+
+	check_gid "$mount_point" "$other_group"
+
+	# Check that files created after the mount inherit the GID
+	local instance=$(create_instance "$mount_point")
+	check_gid "$instance" "$other_group"
+	remove_instance "$instance"
+
+	# Unmount and remount with the original GID
+	unmount_tracefs "$mount_point"
+	mount_tracefs_with_options "$mount_point" "$mount_options"
+	check_gid "$mount_point" "$original_group"
+}
+
+test_gid_mount_option
+
+exit 0