Date: Thu, 17 Nov 2016 20:04:20 +0100
From: Oleg Nesterov <oleg@redhat.com>
To: Jamie Iles <jamie.iles@oracle.com>
Cc: linux-kernel@vger.kernel.org, Alexander Viro <viro@zeniv.linux.org.uk>,
        Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] signal: protect SIGNAL_UNKILLABLE from unintentional
        clearing.
Message-ID: <20161117190420.GA23492@redhat.com>
References: <20161116125759.4727-1-jamie.iles@oracle.com>
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On 11/16, Jamie Iles wrote:
>
> This can result in init becoming stoppable/killable after tracing.  For
> example, running:
>
>   while true; do kill -STOP 1; done &
>   strace -p 1

> and then stopping strace and the kill loop will result in init being
> left in state TASK_STOPPED.  Sending SIGCONT to init will resume it, but
> init will now respond to future SIGSTOP signals rather than ignoring
> them.

Yes, and a lot more... I forgot about these problems again.

Jamie, sorry for delay, I'll try to read the patch and reply tomorrow.

Oleg.