Hi, Oleg:
Yes, it should be the "real_parent" that is more interested in the notification.
Will revert back.
+static void do_notify_parent_predump(void)
+{
+ struct task_struct *parent;
+ int sig;
+
+ rcu_read_lock();
+ parent = rcu_dereference(current->real_parent);
+ sig = parent->signal->predump_signal;
+ if (sig != 0)
+ do_send_sig_info(sig, SEND_SIG_NOINFO, parent, PIDTYPE_TGID);
+ rcu_read_unlock();
+}
Thanks. -- Enke
On 10/29/18 4:18 AM, Oleg Nesterov wrote:
> Hi,
>
> On 10/26, Enke Chen wrote:
>>
>> This is really a good idea given that "parent" is declared as RCU-protected.
>> Just a bit odd, though, that the "parent" has not been accessed this way in
>> the code base.
>
> It is acccessed when possible,
>
>> So just to confirm: the revised code would look like the following:
>>
>> static void do_notify_parent_predump(void)
>> {
>> struct task_struct *parent;
>> int sig;
>>
>> rcu_read_lock();
>> parent = rcu_dereference(current->parent);
>> sig = parent->signal->predump_signal;
>> if (sig != 0)
>> do_send_sig_info(sig, SEND_SIG_NOINFO, parent, PIDTYPE_TGID);
>> rcu_read_unlock();
>> }
>
> Yes, this is what I meant.
>
> But I still think do_notify_parent_predump() should notify ->real_parent,
> not ->parent.
>
> Oleg.
>
