3 files changed, 12 insertions, 13 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 60d6fdcc9265..782b2e1f7ca2 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1575,6 +1575,11 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
         return 0;
 }
 
+void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
+{
+        wake_up_interruptible_sync(&parent->signal->wait_chldexit);
+}
+
 static long do_wait(struct wait_opts *wo)
 {
         DECLARE_WAITQUEUE(wait, current);
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 307c285af59e..23bd09cd042e 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -266,9 +266,10 @@ static int ignoring_children(struct sighand_struct *sigh)
  * or self-reaping.  Do notification now if it would have happened earlier.
  * If it should reap itself, return true.
  *
- * If it's our own child, there is no notification to do.
- * But if our normal children self-reap, then this child
- * was prevented by ptrace and we must reap it now.
+ * If it's our own child, there is no notification to do. But if our normal
+ * children self-reap, then this child was prevented by ptrace and we must
+ * reap it now, in that case we must also wake up sub-threads sleeping in
+ * do_wait().
  */
 static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
 {
@@ -278,8 +279,10 @@ static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
                 if (!task_detached(p) && thread_group_empty(p)) {
                         if (!same_thread_group(p->real_parent, tracer))
                                 do_notify_parent(p, p->exit_signal);
-                        else if (ignoring_children(tracer->sighand))
+                        else if (ignoring_children(tracer->sighand)) {
+                                __wake_up_parent(p, tracer);
                                 p->exit_signal = -1;
+                        }
                 }
                 if (task_detached(p)) {
                         /* Mark it as in the process of being reaped. */
diff --git a/kernel/signal.c b/kernel/signal.c
index 64c5deeaca5d..534ea81cde47 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1383,15 +1383,6 @@ ret:
 }
 
 /*
- * Wake up any threads in the parent blocked in wait* syscalls.
- */
-static inline void __wake_up_parent(struct task_struct *p,
-                                    struct task_struct *parent)
-{
-        wake_up_interruptible_sync(&parent->signal->wait_chldexit);
-}
-
-/*
  * Let a parent know about the death of a child.
  * For a stopped/continued status change, use do_notify_parent_cldstop instead.
  *