[PATCH] futex_find_get_task(): remove an obscure EXIT_ZOMBIE check
Oleg Nesterov [Sun, 27 Aug 2006 08:23:40 +0000 (01:23 -0700)]
futex_find_get_task:

if (p->state == EXIT_ZOMBIE || p->exit_state == EXIT_ZOMBIE)
return NULL;

I can't understand this.  First, p->state can't be EXIT_ZOMBIE.  The
->exit_state check looks strange too.  Sub-threads or tasks whose ->parent
ignores SIGCHLD go directly to EXIT_DEAD state (I am ignoring a ptrace
case).  Why EXIT_DEAD tasks should be ok?  Yes, EXIT_ZOMBIE is more
important (a task may stay zombie for a long time), but this doesn't mean
we should explicitely ignore other EXIT_XXX states.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/futex.c

index d4633c5..b9b8aea 100644 (file)
@@ -397,7 +397,7 @@ static struct task_struct * futex_find_get_task(pid_t pid)
                p = NULL;
                goto out_unlock;
        }
-       if (p->state == EXIT_ZOMBIE || p->exit_state == EXIT_ZOMBIE) {
+       if (p->exit_state != 0) {
                p = NULL;
                goto out_unlock;
        }