Re: NFS causing oops when freeing namespace

From: Oleg Nesterov
Date: Wed Jan 17 2007 - 17:56:38 EST


On 01/17, Eric W. Biederman wrote:
>
> Cedric Le Goater <clg@xxxxxxxxxx> writes:
> >
> > your first analysis was correct : exit_task_namespaces() should be moved
> > above exit_notify(tsk). It will require some extra fixes for nsproxy
> > though.
>
> I think the only issue is the child_reaper and currently we only have one of
> those. When we really do the pid namespace we are going to have to revisit
> this. My gut feel says that we won't be able to exit our pid namespace until
> the process is waited on. So we may need to break up exit_task_namespace into
> individual components.

I agree, but please note that the child_reaper is not the only issue. Think
about sub-thread which auto-reaps itself. I'd suggest to add the comment in
do_exit() after exit_notify() to remind that the task is really dead now, it
has no ->signal, it can't be seen in /proc/, we can't send a signal to it, etc.

Oleg.

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