diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c
index 4c54b25..ecfe83a 100644
--- a/samples/livepatch/livepatch-shadow-mod.c
+++ b/samples/livepatch/livepatch-shadow-mod.c
@@ -1,18 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2017 Joe Lawrence <joe.lawrence@redhat.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 /*
@@ -96,15 +84,15 @@
  * Keep a list of all the dummies so we can clean up any residual ones
  * on module exit
  */
-LIST_HEAD(dummy_list);
-DEFINE_MUTEX(dummy_list_mutex);
+static LIST_HEAD(dummy_list);
+static DEFINE_MUTEX(dummy_list_mutex);
 
 struct dummy {
 	struct list_head list;
 	unsigned long jiffies_expire;
 };
 
-noinline struct dummy *dummy_alloc(void)
+static __used noinline struct dummy *dummy_alloc(void)
 {
 	struct dummy *d;
 	void *leak;
@@ -118,6 +106,10 @@
 
 	/* Oops, forgot to save leak! */
 	leak = kzalloc(sizeof(int), GFP_KERNEL);
+	if (!leak) {
+		kfree(d);
+		return NULL;
+	}
 
 	pr_info("%s: dummy @ %p, expires @ %lx\n",
 		__func__, d, d->jiffies_expire);
@@ -125,7 +117,7 @@
 	return d;
 }
 
-noinline void dummy_free(struct dummy *d)
+static __used noinline void dummy_free(struct dummy *d)
 {
 	pr_info("%s: dummy @ %p, expired = %lx\n",
 		__func__, d, d->jiffies_expire);
@@ -133,7 +125,8 @@
 	kfree(d);
 }
 
-noinline bool dummy_check(struct dummy *d, unsigned long jiffies)
+static __used noinline bool dummy_check(struct dummy *d,
+					   unsigned long jiffies)
 {
 	return time_after(jiffies, d->jiffies_expire);
 }