Re: unshare() pid ns

[Cedric Le Goater <clg-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>]

Hello Pavel ! 

Pavel Emelyanov wrote:
> Serge E. Hallyn wrote:
>> Quoting Pavel Emelyanov (xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org):
>>> sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org wrote:
>>>> Pavel,
>>>> unshare() of pid ns seems to fail with -EINVAL in 2.6.23-rc3-mm1.
>>>> I thought we supported it in the earlier patchsets.  I guess
>>>> I missed that in the review of recent patchsets.
>>> I disabled unsharing of pid namespaces because it's almost
>>> impossible. Look - you have to reattach all the pids to the
>>> task with saving its ids as seen in previous namespaces.
>> We agree, but thought you for some perverse reason preferred unshare to
>> clone for pidns :)
> 
> I did that in my first version of patches, but then realized
> that such problem (the need in reattaching pids) makes the
> unsharing ugly.
> 
> BTW, unsharing of a pid namespace is a valid operation, so I
> think I will enable it in the nearest future. I have some
> thought on how to make such a reattach ;)

that would be also very useful to 'enter' such a namespace.

BTW, did you take a look at the sys_hijack() serge sent ? 

Thanks,

C.