v4.19.13 snapshot.
diff --git a/include/linux/sem.h b/include/linux/sem.h
new file mode 100644
index 0000000..5608a50
--- /dev/null
+++ b/include/linux/sem.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_SEM_H
+#define _LINUX_SEM_H
+
+#include <uapi/linux/sem.h>
+
+struct task_struct;
+struct sem_undo_list;
+
+#ifdef CONFIG_SYSVIPC
+
+struct sysv_sem {
+ struct sem_undo_list *undo_list;
+};
+
+extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
+extern void exit_sem(struct task_struct *tsk);
+
+#else
+
+struct sysv_sem {
+ /* empty */
+};
+
+static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
+{
+ return 0;
+}
+
+static inline void exit_sem(struct task_struct *tsk)
+{
+ return;
+}
+#endif
+
+#endif /* _LINUX_SEM_H */