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>

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>
Oleg Nesterov
1 parent 06d984737b
Showing 3 changed files with 17 additions and 13 deletions Side-by-side Diff
include/linux/sched.h
kernel/exit.c
kernel/signal.c
@@ -2145,7 +2145,7 @@
 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
  
 	return ret;
-}	
+}
  
 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
 			      sigset_t *mask);
@@ -2160,7 +2160,7 @@
 extern int kill_pgrp(struct pid *pid, int sig, int priv);
 extern int kill_pid(struct pid *pid, int sig, int priv);
 extern int kill_proc_info(int, struct siginfo *, pid_t);
-extern int do_notify_parent(struct task_struct *, int);
+extern bool do_notify_parent(struct task_struct *, int);
 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
 extern void force_sig(int, struct task_struct *);
 extern int send_sig(int, struct task_struct *, int);
@@ -820,6 +820,7 @@
 static void exit_notify(struct task_struct *tsk, int group_dead)
 {
 	int signal;
+	bool autoreap;
 	void *cookie;
  
 	/*
  
@@ -858,9 +859,11 @@
  
 	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 @@
 	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);
 }
  
@@ -1577,15 +1577,15 @@
  * 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 @@
 		 * 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;
 }
  
 /**
...	...	@@ -2145,7 +2145,7 @@
2145	2145	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2146	2146
2147	2147	return ret;
2148		-}
	2148	+}
2149	2149
2150	2150	extern void block_all_signals(int (notifier)(void priv), void *priv,
2151	2151	sigset_t *mask);
...	...	@@ -2160,7 +2160,7 @@
2160	2160	extern int kill_pgrp(struct pid *pid, int sig, int priv);
2161	2161	extern int kill_pid(struct pid *pid, int sig, int priv);
2162	2162	extern int kill_proc_info(int, struct siginfo *, pid_t);
2163		-extern int do_notify_parent(struct task_struct *, int);
	2163	+extern bool do_notify_parent(struct task_struct *, int);
2164	2164	extern void __wake_up_parent(struct task_struct p, struct task_struct parent);
2165	2165	extern void force_sig(int, struct task_struct *);
2166	2166	extern int send_sig(int, struct task_struct *, int);
...	...	@@ -820,6 +820,7 @@
820	820	static void exit_notify(struct task_struct *tsk, int group_dead)
821	821	{
822	822	int signal;
	823	+ bool autoreap;
823	824	void *cookie;
824	825
825	826	/*
826	827
...	...	@@ -858,9 +859,11 @@
858	859
859	860	signal = tracehook_notify_death(tsk, &cookie, group_dead);
860	861	if (signal >= 0)
861		- signal = do_notify_parent(tsk, signal);
	862	+ autoreap = do_notify_parent(tsk, signal);
	863	+ else
	864	+ autoreap = (signal == DEATH_REAP);
862	865
863		- tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE;
	866	+ tsk->exit_state = autoreap ? EXIT_DEAD : EXIT_ZOMBIE;
864	867
865	868	/* mt-exec, de_thread() is waiting for group leader */
866	869	if (unlikely(tsk->signal->notify_count < 0))
...	...	@@ -868,7 +871,7 @@
868	871	write_unlock_irq(&tasklist_lock);
869	872
870	873	/* If the process is dead, release it - nobody will wait for it */
871		- if (signal == DEATH_REAP)
	874	+ if (autoreap)
872	875	release_task(tsk);
873	876	}
874	877
...	...	@@ -1577,15 +1577,15 @@
1577	1577	* Let a parent know about the death of a child.
1578	1578	* For a stopped/continued status change, use do_notify_parent_cldstop instead.
1579	1579	*
1580		- * Returns -1 if our parent ignored us and so we've switched to
1581		- * self-reaping, or else @sig.
	1580	+ * Returns true if our parent ignored us and so we've switched to
	1581	+ * self-reaping.
1582	1582	*/
1583		-int do_notify_parent(struct task_struct *tsk, int sig)
	1583	+bool do_notify_parent(struct task_struct *tsk, int sig)
1584	1584	{
1585	1585	struct siginfo info;
1586	1586	unsigned long flags;
1587	1587	struct sighand_struct *psig;
1588		- int ret = sig;
	1588	+ bool autoreap = false;
1589	1589
1590	1590	BUG_ON(sig == -1);
1591	1591
1592	1592
1593	1593
1594	1594
...	...	@@ -1649,16 +1649,17 @@
1649	1649	* is implementation-defined: we do (if you don't want
1650	1650	* it, just use SIG_IGN instead).
1651	1651	*/
1652		- ret = tsk->exit_signal = -1;
	1652	+ autoreap = true;
	1653	+ tsk->exit_signal = -1;
1653	1654	if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
1654		- sig = -1;
	1655	+ sig = 0;
1655	1656	}
1656		- if (valid_signal(sig) && sig > 0)
	1657	+ if (valid_signal(sig) && sig)
1657	1658	__group_send_sig_info(sig, &info, tsk->parent);
1658	1659	__wake_up_parent(tsk, tsk->parent);
1659	1660	spin_unlock_irqrestore(&psig->siglock, flags);
1660	1661
1661		- return ret;
	1662	+ return autoreap;
1662	1663	}
1663	1664
1664	1665	/**