make do_notify_parent() return bool

- change do_notify_parent() to return a boolean, true if the task should
  be reaped because its parent ignores SIGCHLD.

- update the only caller which checks the returned value, exit_notify().

This temporary uglifies exit_notify() even more, will be cleanuped by
the next change.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>

2 files changed, 15 insertions, 11 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index d49134a7f250..34d135f4fccc 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -820,6 +820,7 @@ static void forget_original_parent(struct task_struct *father)
 static void exit_notify(struct task_struct *tsk, int group_dead)
 {
         int signal;
+        bool autoreap;
         void *cookie;
 
         /*
@@ -858,9 +859,11 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
 
         signal = tracehook_notify_death(tsk, &cookie, group_dead);
         if (signal >= 0)
-                signal = do_notify_parent(tsk, signal);
+                autoreap = do_notify_parent(tsk, signal);
+        else
+                autoreap = (signal == DEATH_REAP);
 
-        tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE;
+        tsk->exit_state = autoreap ? EXIT_DEAD : EXIT_ZOMBIE;
 
         /* mt-exec, de_thread() is waiting for group leader */
         if (unlikely(tsk->signal->notify_count < 0))
@@ -868,7 +871,7 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
         write_unlock_irq(&tasklist_lock);
 
         /* If the process is dead, release it - nobody will wait for it */
-        if (signal == DEATH_REAP)
+        if (autoreap)
                 release_task(tsk);
 }
 
diff --git a/kernel/signal.c b/kernel/signal.c
index 1550aee34f42..d52e82cd62bb 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1577,15 +1577,15 @@ ret:
  * Let a parent know about the death of a child.
  * For a stopped/continued status change, use do_notify_parent_cldstop instead.
  *
- * Returns -1 if our parent ignored us and so we've switched to
- * self-reaping, or else @sig.
+ * Returns true if our parent ignored us and so we've switched to
+ * self-reaping.
  */
-int do_notify_parent(struct task_struct *tsk, int sig)
+bool do_notify_parent(struct task_struct *tsk, int sig)
 {
         struct siginfo info;
         unsigned long flags;
         struct sighand_struct *psig;
-        int ret = sig;
+        bool autoreap = false;
 
         BUG_ON(sig == -1);
 
@@ -1649,16 +1649,17 @@ int do_notify_parent(struct task_struct *tsk, int sig)
                  * is implementation-defined: we do (if you don't want
                  * it, just use SIG_IGN instead).
                  */
-                ret = tsk->exit_signal = -1;
+                autoreap = true;
+                tsk->exit_signal = -1;
                 if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
-                        sig = -1;
+                        sig = 0;
         }
-        if (valid_signal(sig) && sig > 0)
+        if (valid_signal(sig) && sig)
                 __group_send_sig_info(sig, &info, tsk->parent);
         __wake_up_parent(tsk, tsk->parent);
         spin_unlock_irqrestore(&psig->siglock, flags);
 
-        return ret;
+        return autoreap;
 }
 
 /**