selftests/user_events: Clear the events after perf self-test

When the self test is completed, perf self-test left the user events not to
be cleared. Clear the events by unregister and delete the event.

Link: https://lkml.kernel.org/r/20230606062027.1008398-4-sunliming@kylinos.cn

Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Author: sunliming

tools/testing/selftests/user_events/perf_test.c

@@ -81,6 +81,32 @@ static int get_offset(void)
 	return offset;
 }
 
+static int clear(int *check)
+{
+	struct user_unreg unreg = {0};
+
+	unreg.size = sizeof(unreg);
+	unreg.disable_bit = 31;
+	unreg.disable_addr = (__u64)check;
+
+	int fd = open(data_file, O_RDWR);
+
+	if (fd == -1)
+		return -1;
+
+	if (ioctl(fd, DIAG_IOCSUNREG, &unreg) == -1)
+		if (errno != ENOENT)
+			return -1;
+
+	if (ioctl(fd, DIAG_IOCSDEL, "__test_event") == -1)
+		if (errno != ENOENT)
+			return -1;
+
+	close(fd);
+
+	return 0;
+}
+
 FIXTURE(user) {
 	int data_fd;
 	int check;
@@ -93,6 +119,9 @@ FIXTURE_SETUP(user) {
 
 FIXTURE_TEARDOWN(user) {
 	close(self->data_fd);
+
+	if (clear(&self->check) != 0)
+		printf("WARNING: Clear didn't work!\n");
 }
 
 TEST_F(user, perf_write) {