Merge branch 'linus' into sched/clock

1 files changed, 15 insertions, 9 deletions

diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index b1875582c1a..b48d8196957 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -280,7 +280,7 @@ static inline void tracehook_report_clone(int trace, struct pt_regs *regs,
 					  unsigned long clone_flags,
 					  pid_t pid, struct task_struct *child)
 {
-	if (unlikely(trace)) {
+	if (unlikely(trace) || unlikely(clone_flags & CLONE_PTRACE)) {
 		/*
 		 * The child starts up with an immediate SIGSTOP.
 		 */
@@ -487,14 +487,20 @@ static inline int tracehook_notify_jctl(int notify, int why)
 	return notify || (current->ptrace & PT_PTRACED);
 }
 
+#define DEATH_REAP			-1
+#define DEATH_DELAYED_GROUP_LEADER	-2
+
 /**
  * tracehook_notify_death - task is dead, ready to notify parent
  * @task:		@current task now exiting
  * @death_cookie:	value to pass to tracehook_report_death()
  * @group_dead:		nonzero if this was the last thread in the group to die
  *
- * Return the signal number to send our parent with do_notify_parent(), or
- * zero to send no signal and leave a zombie, or -1 to self-reap right now.
+ * A return value >= 0 means call do_notify_parent() with that signal
+ * number.  Negative return value can be %DEATH_REAP to self-reap right
+ * now, or %DEATH_DELAYED_GROUP_LEADER to a zombie without notifying our
+ * parent.  Note that a return value of 0 means a do_notify_parent() call
+ * that sends no signal, but still wakes up a parent blocked in wait*().
  *
  * Called with write_lock_irq(&tasklist_lock) held.
  */
@@ -502,7 +508,7 @@ static inline int tracehook_notify_death(struct task_struct *task,
 					 void **death_cookie, int group_dead)
 {
 	if (task->exit_signal == -1)
-		return task->ptrace ? SIGCHLD : -1;
+		return task->ptrace ? SIGCHLD : DEATH_REAP;
 
 	/*
 	 * If something other than our normal parent is ptracing us, then
@@ -512,21 +518,21 @@ static inline int tracehook_notify_death(struct task_struct *task,
 	if (thread_group_empty(task) && !ptrace_reparented(task))
 		return task->exit_signal;
 
-	return task->ptrace ? SIGCHLD : 0;
+	return task->ptrace ? SIGCHLD : DEATH_DELAYED_GROUP_LEADER;
 }
 
 /**
  * tracehook_report_death - task is dead and ready to be reaped
  * @task:		@current task now exiting
- * @signal:		signal number sent to parent, or 0 or -1
+ * @signal:		return value from tracheook_notify_death()
  * @death_cookie:	value passed back from tracehook_notify_death()
  * @group_dead:		nonzero if this was the last thread in the group to die
  *
  * Thread has just become a zombie or is about to self-reap.  If positive,
  * @signal is the signal number just sent to the parent (usually %SIGCHLD).
- * If @signal is -1, this thread will self-reap.  If @signal is 0, this is
- * a delayed_group_leader() zombie.  The @death_cookie was passed back by
- * tracehook_notify_death().
+ * If @signal is %DEATH_REAP, this thread will self-reap.  If @signal is
+ * %DEATH_DELAYED_GROUP_LEADER, this is a delayed_group_leader() zombie.
+ * The @death_cookie was passed back by tracehook_notify_death().
  *
  * If normal reaping is not inhibited, @task->exit_state might be changing
  * in parallel.