[PATCH 0/2] (Was: pppd service crash in linux-3.13.6)

From: Oleg Nesterov
Date: Mon Mar 17 2014 - 14:05:15 EST


On 03/15, Peter Hurley wrote:
>
> On 03/14/2014 05:04 PM, Oleg Nesterov wrote:
>>
>> But it can't even know who called call_usermodehelper(). Besides,
>> cgroup_release_agent() uses UMH_WAIT_EXEC, so the caller can continue
>> and disappear completely before the usermode process has any chance
>> to do something.
>
> I'm just hypothesizing potential breakage, since the order of teardown
> is sensitive to changes, and I didn't do a complete audit of all the
> possibilities.

Yes, I understand your concerns. Still I do not see how cgroup_exit()
can depend on tty/namespace.

> If you feel strongly about moving disassociate_tty(), I won't object.

It is not that I feel really strongly... just in looks better to me.
If nothing else:

1. If we actually can not do disassociate_ctty() before, say,
cgroup_exit(), then we should understand and document the
reason.

2. task_work_add() can have more users in drivers/tty which
can be triggered by disassociate_tty() paths. So I think
it would be nice to call it before task_work_exit().

2/2 is offtopic and hopefully trivial.

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/