tracehook: TIF_NOTIFY_RESUME

[linux-2.6-omap-h63xx.git] / include / linux / tracehook.h

diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index 43bc51b6bd33e7783ef61c1b049ee9c71276b8ff..32867ab86c7030502ea88675a1011748db92c090 100644 (file)
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -537,4 +537,38 @@ static inline void tracehook_report_death(struct task_struct *task,
 {
 }
 
+#ifdef TIF_NOTIFY_RESUME
+/**
+ * set_notify_resume - cause tracehook_notify_resume() to be called
+ * @task:              task that will call tracehook_notify_resume()
+ *
+ * Calling this arranges that @task will call tracehook_notify_resume()
+ * before returning to user mode.  If it's already running in user mode,
+ * it will enter the kernel and call tracehook_notify_resume() soon.
+ * If it's blocked, it will not be woken.
+ */
+static inline void set_notify_resume(struct task_struct *task)
+{
+       if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME))
+               kick_process(task);
+}
+
+/**
+ * tracehook_notify_resume - report when about to return to user mode
+ * @regs:              user-mode registers of @current task
+ *
+ * This is called when %TIF_NOTIFY_RESUME has been set.  Now we are
+ * about to return to user mode, and the user state in @regs can be
+ * inspected or adjusted.  The caller in arch code has cleared
+ * %TIF_NOTIFY_RESUME before the call.  If the flag gets set again
+ * asynchronously, this will be called again before we return to
+ * user mode.
+ *
+ * Called without locks.
+ */
+static inline void tracehook_notify_resume(struct pt_regs *regs)
+{
+}
+#endif /* TIF_NOTIFY_RESUME */
+
 #endif /* <linux/tracehook.h> */