It predates the git history and most probably it was never needed. It
doesn't really hurt, but it looks confusing because its purpose is not
clear at all.

release_task(p) is called when this task has already passed exit_notify()
so signal_pending(p) == T shouldn't make any difference.

And even _if_ there were a subtle reason to clear TIF_SIGPENDING after
exit_notify(), this clear_tsk_thread_flag() can't help anyway.  If the
exiting task is a group leader or if it is ptraced, release_task() will
be likely called when this task has already done its last schedule() from
do_task_dead().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 kernel/exit.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index 2d7444da743d..0acb94b17caa 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -204,7 +204,6 @@ static void __exit_signal(struct task_struct *tsk)
 	spin_unlock(&sighand->siglock);
 
 	__cleanup_sighand(sighand);
-	clear_tsk_thread_flag(tsk, TIF_SIGPENDING);
 	if (group_dead)
 		tty_kref_put(tty);
 }
-- 
2.25.1.362.g51ebf55

Le Thu, Feb 06, 2025 at 04:23:34PM +0100, Oleg Nesterov a écrit :
> It predates the git history and most probably it was never needed. It
> doesn't really hurt, but it looks confusing because its purpose is not
> clear at all.
> 
> release_task(p) is called when this task has already passed exit_notify()
> so signal_pending(p) == T shouldn't make any difference.
> 
> And even _if_ there were a subtle reason to clear TIF_SIGPENDING after
> exit_notify(), this clear_tsk_thread_flag() can't help anyway.  If the
> exiting task is a group leader or if it is ptraced, release_task() will
> be likely called when this task has already done its last schedule() from
> do_task_dead().
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Acked-by: Frederic Weisbecker <frederic@kernel.org>