Currently we remap task_entries but it can be used from a sigchld hanler.
We need to block sigchld to remap task_entries and unlock it
when a restorer sigchld handler is set.
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Reviewed-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>