Add a sticky "PF_DEAD" task flag to keep track of dead processes.

Use this to simplify 'finish_task_switch', but perhaps more
importantly we can use this to track down why some processes
seem to sometimes not die properly even after having been
marked as ZOMBIE. The "task->state" flags are too fluid to 
allow that well.

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 25b62f5971be..32f739f782d1 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -688,6 +688,7 @@ static void exit_notify(struct task_struct *tsk)
 	}
 
 	tsk->state = TASK_ZOMBIE;
+	tsk->flags |= PF_DEAD;
 	/*
 	 * In the preemption case it must be impossible for the task
 	 * to get runnable again, so use "_raw_" unlock to keep