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Subject: Re: [regression, 2.6.37-rc1] 'ip link tap0 up' stuck in do_exit()
From: Eric Dumazet <eric.dumazet@gmail.com>
To: =?ISO-8859-1?Q?Am=E9rico?= Wang <xiyou.wangcong@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>, Florian Mickler <florian@mickler.org>,
        Ingo Molnar <mingo@elte.hu>, Dave Chinner <david@fromorbit.com>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org
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Content-Type: text/plain; charset="UTF-8"
Date: Thu, 09 Dec 2010 18:09:29 +0100
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Le jeudi 09 décembre 2010 à 18:07 +0100, Eric Dumazet a écrit :
> Le vendredi 10 décembre 2010 à 00:47 +0800, Américo Wang a écrit :
> 
> > Yeah, there is no point that a zombie can trigger a BUG_ON in kenrel.
> > But it is still interesting to know why it becomes a zombie...
> > 
> 
> A zombie is very easy to get.
> 
> Technically speaking, all processes die and become zombies, unless
> parent said : signal(SIGCLD, SIG_IGN) before fork()
> 
> The parent is buggy (sudo in this case ?) and doesnt call wait() to
> 'free' one of its children.
> 
> 

Before you ask :)

If the parent dies before the child, task is re-parented to init.

Then, with namespaces, I dont know what happens (is there one init per
namespace ?)


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