task_work_add: generic process-context callbacks

[mirror_ubuntu-bionic-kernel.git] / include / linux / tracehook.h

diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index b9ca903bb553ff22a0d3502820c4a4776e3b3342..b2dd0917ca0d6d9a1ecaed8a78324f5ddbaaa32a 100644 (file)
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -49,6 +49,7 @@
 #include <linux/sched.h>
 #include <linux/ptrace.h>
 #include <linux/security.h>
+#include <linux/task_work.h>
 struct linux_binprm;
 
 /*
@@ -164,8 +165,10 @@ static inline void tracehook_signal_handler(int sig, siginfo_t *info,
  */
 static inline void set_notify_resume(struct task_struct *task)
 {
+#ifdef TIF_NOTIFY_RESUME
        if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME))
                kick_process(task);
+#endif
 }
 
 /**
@@ -185,6 +188,14 @@ static inline void tracehook_notify_resume(struct pt_regs *regs)
 {
        if (current->replacement_session_keyring)
                key_replace_session_keyring();
+       /*
+        * The caller just cleared TIF_NOTIFY_RESUME. This barrier
+        * pairs with task_work_add()->set_notify_resume() after
+        * hlist_add_head(task->task_works);
+        */
+       smp_mb__after_clear_bit();
+       if (unlikely(!hlist_empty(&current->task_works)))
+               task_work_run();
 }
 
 #endif /* <linux/tracehook.h> */