On 10/25, Enke Chen wrote: > > +static void do_notify_parent_predump(void) > +{ > + struct task_struct *parent; > + int sig; > + > + read_lock(&tasklist_lock); > + parent = current->parent; > + sig = parent->signal->predump_signal; > + if (sig != 0) > + do_send_sig_info(sig, SEND_SIG_NOINFO, parent, PIDTYPE_TGID); > + read_unlock(&tasklist_lock); Ah. It is strange I didn't think about this before... Please, do not take tasklist_lock, use rcu_read_lock() instead. do_send_sig_info() uses the rcu-friendly lock_task_sighand(), so rcu_dereference(parent) should work fine. Oleg.