v4.19.13 snapshot.
diff --git a/include/linux/sched/user.h b/include/linux/sched/user.h
new file mode 100644
index 0000000..39ad98c
--- /dev/null
+++ b/include/linux/sched/user.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_SCHED_USER_H
+#define _LINUX_SCHED_USER_H
+
+#include <linux/uidgid.h>
+#include <linux/atomic.h>
+#include <linux/refcount.h>
+#include <linux/ratelimit.h>
+
+struct key;
+
+/*
+ * Some day this will be a full-fledged user tracking system..
+ */
+struct user_struct {
+ refcount_t __count; /* reference count */
+ atomic_t processes; /* How many processes does this user have? */
+ atomic_t sigpending; /* How many pending signals does this user have? */
+#ifdef CONFIG_FANOTIFY
+ atomic_t fanotify_listeners;
+#endif
+#ifdef CONFIG_EPOLL
+ atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
+#endif
+#ifdef CONFIG_POSIX_MQUEUE
+ /* protected by mq_lock */
+ unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
+#endif
+ unsigned long locked_shm; /* How many pages of mlocked shm ? */
+ unsigned long unix_inflight; /* How many files in flight in unix sockets */
+ atomic_long_t pipe_bufs; /* how many pages are allocated in pipe buffers */
+
+#ifdef CONFIG_KEYS
+ struct key *uid_keyring; /* UID specific keyring */
+ struct key *session_keyring; /* UID's default session keyring */
+#endif
+
+ /* Hash table maintenance information */
+ struct hlist_node uidhash_node;
+ kuid_t uid;
+
+#if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL) || \
+ defined(CONFIG_NET)
+ atomic_long_t locked_vm;
+#endif
+
+ /* Miscellaneous per-user rate limit */
+ struct ratelimit_state ratelimit;
+};
+
+extern int uids_sysfs_init(void);
+
+extern struct user_struct *find_user(kuid_t);
+
+extern struct user_struct root_user;
+#define INIT_USER (&root_user)
+
+
+/* per-UID process charging. */
+extern struct user_struct * alloc_uid(kuid_t);
+static inline struct user_struct *get_uid(struct user_struct *u)
+{
+ refcount_inc(&u->__count);
+ return u;
+}
+extern void free_uid(struct user_struct *);
+
+#endif /* _LINUX_SCHED_USER_H */