Re: + daemonize-detach-from-current-namespace.patch added to -mm tree

[ebiederm@xmission.com (Eric W. Biederman)]

Andrew Morton <akpm@osdl.org> writes:

> ebiederm@xmission.com (Eric W. Biederman) wrote:
>>
>> I am beginning to suspect that we will want to fix kernel_thread so it
>>  creates copies of the init_task rather than copies of whatever random
>>  user space process we happen to be a member of at the time.  With an
>>  enhanced kernel_thread this problem could more easily avoided, as
>>  we add additional namespaces to the kernel.
>
> You wouldn't believe the problems we had with kernel_thread followed by
> call_usermodehelper() due to inheritance of random stuff from the userspace
> parent.
>
> A suitable solution is to stop using kernel_thread(), migrate to the
> kthread API - that way the threads are parented by keventd which is a known
> and good environment.

Thanks.  This sounds worth investigating.

On the other hand call_usermodehelper is the one case where we might
want to share some of the attributes with an existing process, at
least if we ever want it to run in a non-default namespace.

Eric