v4.19.13 snapshot.
diff --git a/include/linux/ipc.h b/include/linux/ipc.h
new file mode 100644
index 0000000..e1c9eea
--- /dev/null
+++ b/include/linux/ipc.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_IPC_H
+#define _LINUX_IPC_H
+
+#include <linux/spinlock.h>
+#include <linux/uidgid.h>
+#include <linux/rhashtable-types.h>
+#include <uapi/linux/ipc.h>
+#include <linux/refcount.h>
+
+/* used by in-kernel data structures */
+struct kern_ipc_perm {
+ spinlock_t lock;
+ bool deleted;
+ int id;
+ key_t key;
+ kuid_t uid;
+ kgid_t gid;
+ kuid_t cuid;
+ kgid_t cgid;
+ umode_t mode;
+ unsigned long seq;
+ void *security;
+
+ struct rhash_head khtnode;
+
+ struct rcu_head rcu;
+ refcount_t refcount;
+} ____cacheline_aligned_in_smp __randomize_layout;
+
+#endif /* _LINUX_IPC_H */