From: Jamie Iles <jamie.iles@oracle.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Jamie Iles <jamie.iles@oracle.com>,
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.
Date: Mon, 28 Nov 2016 12:14:34 +0000 [thread overview]
Message-ID: <20161128121434.4it7yd7wmpkxv6f4@cedar> (raw)
In-Reply-To: <20161117190420.GA23492@redhat.com>
Hi Oleg,
On Thu, Nov 17, 2016 at 08:04:20PM +0100, Oleg Nesterov wrote:
> 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.
Did you get chance to look at the patch? I did have another thought -
rather than the accessors, we could change signal_struct to have:
unsigned int unkillable:1;
unsigned int flags:31;
to separate signal_unkillable from flags, making it a bit safer in the
future.
Jamie
next prev parent reply other threads:[~2016-11-28 12:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 12:57 [PATCH] signal: protect SIGNAL_UNKILLABLE from unintentional clearing Jamie Iles
2016-11-17 19:04 ` Oleg Nesterov
2016-11-28 12:14 ` Jamie Iles [this message]
2016-11-29 14:06 ` Oleg Nesterov
2016-11-29 14:23 ` Jamie Iles
2016-12-01 17:45 ` Oleg Nesterov
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