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Date: Thu, 23 Feb 2012 16:17:54 +0100
From: Oleg Nesterov <oleg@redhat.com>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: tj@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [ptrace] Problem with ptrace cleanup logic.
Message-ID: <20120223151754.GA1065@redhat.com>
References: <201202230526.q1N5QdUc035041@www262.sakura.ne.jp>
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On 02/23, Tetsuo Handa wrote:
>
> I noticed that ptrace(PTRACE_ATTACH, 1) makes the global init process remain
> killable even after a process that called ptrace(PTRACE_ATTACH, 1) exits.

Yes, known problem. We should cleanup the usage of signal->flags.
This also allows to kill the new bitfields in signal_struct.

But firstly we should cleanup force_sig_info(), I sent the initial
patches.

The problem is: init loses SIGNAL_UNKILLABLE.

Oleg.