1 files changed, 49 insertions, 0 deletions
diff --git a/include/linux/user-return-notifier.h b/include/linux/user-return-notifier.h
new file mode 100644
index 000000000000..9c4a445bb43c
--- /dev/null
+++ b/include/linux/user-return-notifier.h
@@ -0,0 +1,49 @@
+#ifndef _LINUX_USER_RETURN_NOTIFIER_H
+#define _LINUX_USER_RETURN_NOTIFIER_H
+
+#ifdef CONFIG_USER_RETURN_NOTIFIER
+
+#include <linux/list.h>
+#include <linux/sched.h>
+
+struct user_return_notifier {
+	void (*on_user_return)(struct user_return_notifier *urn);
+	struct hlist_node link;
+};
+
+
+void user_return_notifier_register(struct user_return_notifier *urn);
+void user_return_notifier_unregister(struct user_return_notifier *urn);
+
+static inline void propagate_user_return_notify(struct task_struct *prev,
+						struct task_struct *next)
+{
+	if (test_tsk_thread_flag(prev, TIF_USER_RETURN_NOTIFY)) {
+		clear_tsk_thread_flag(prev, TIF_USER_RETURN_NOTIFY);
+		set_tsk_thread_flag(next, TIF_USER_RETURN_NOTIFY);
+	}
+}
+
+void fire_user_return_notifiers(void);
+
+static inline void clear_user_return_notifier(struct task_struct *p)
+{
+	clear_tsk_thread_flag(p, TIF_USER_RETURN_NOTIFY);
+}
+
+#else
+
+struct user_return_notifier {};
+
+static inline void propagate_user_return_notify(struct task_struct *prev,
+						struct task_struct *next)
+{
+}
+
+static inline void fire_user_return_notifiers(void) {}
+
+static inline void clear_user_return_notifier(struct task_struct *p) {}
+
+#endif
+
+#endif