signal: do_signal_stop: Remove the unneeded task_clear_group_stop_pending()
PF_EXITING or TASK_STOPPED has already called task_participate_group_stop()
and cleared its ->group_stop. No need to do task_clear_group_stop_pending()
when we start the new group stop.
Add a small comment to explain the !task_is_stopped() check. Note that this
check is not exactly right and it can lead to unnecessary stop later if the
thread is TASK_PTRACED. What we need is task_participated_in_group_stop(),
this will be solved later.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/signal.c b/kernel/signal.c
index 38ea9e2..e9abc69 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1866,7 +1866,8 @@
* still in effect and then receive a stop signal and
* initiate another group stop. This deviates from the
* usual behavior as two consecutive stop signals can't
- * cause two group stops when !ptraced.
+ * cause two group stops when !ptraced. That is why we
+ * also check !task_is_stopped(t) below.
*
* The condition can be distinguished by testing whether
* SIGNAL_STOP_STOPPED is already set. Don't generate
@@ -1896,8 +1897,6 @@
t->group_stop |= signr | gstop;
sig->group_stop_count++;
signal_wake_up(t, 0);
- } else {
- task_clear_group_stop_pending(t);
}
}
}