2007-08-05 15:24:57

by Oleg Nesterov

Subject: [PATCH] exit_notify: don't take tasklist for TIF_SIGPENDING re-targeting

->siglock provides enough protection to iterate over the thread group.

Signed-off-by: Oleg Nesterov <[email protected]>

--- t/kernel/exit.c~3_SIGPEND 2007-08-05 18:54:09.000000000 +0400
+++ t/kernel/exit.c 2007-08-05 19:16:38.000000000 +0400
@@ -756,13 +756,11 @@ static void exit_notify(struct task_stru
* Now we'll wake all the threads in the group just to make
* sure someone gets all the pending signals.
*/
- read_lock(&tasklist_lock);
spin_lock_irq(&tsk->sighand->siglock);
for (t = next_thread(tsk); t != tsk; t = next_thread(t))
if (!signal_pending(t) && !(t->flags & PF_EXITING))
recalc_sigpending_and_wake(t);
spin_unlock_irq(&tsk->sighand->siglock);
- read_unlock(&tasklist_lock);
}

write_lock_irq(&tasklist_lock);
@@ -790,9 +788,8 @@ static void exit_notify(struct task_stru
* and we were the only connection outside, so our pgrp
* is about to become orphaned.
*/
-
t = tsk->real_parent;
-
+
pgrp = task_pgrp(tsk);
if ((task_pgrp(t) != pgrp) &&
(task_session(t) == task_session(tsk)) &&

2007-08-05 20:47:48

by Roland McGrath

Subject: Re: [PATCH] exit_notify: don't take tasklist for TIF_SIGPENDING re-targeting

Looks fine to me.

Thanks,
Roland