From: Oleg Nesterov <oleg@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: qianli zhao <zhaoqianligood@gmail.com>,
christian@brauner.io, axboe@kernel.dk,
Thomas Gleixner <tglx@linutronix.de>,
Peter Collingbourne <pcc@google.com>,
linux-kernel@vger.kernel.org, Qianli Zhao <zhaoqianli@xiaomi.com>
Subject: Re: [PATCH V3] exit: trigger panic when global init has exited
Date: Fri, 19 Mar 2021 17:26:50 +0100 [thread overview]
Message-ID: <20210319162649.GA19971@redhat.com> (raw)
In-Reply-To: <m1pmzwb7pd.fsf@fess.ebiederm.org>
On 03/18, Eric W. Biederman wrote:
>
> Oleg Nesterov <oleg@redhat.com> writes:
>
> > On 03/18, qianli zhao wrote:
> >>
> >> In addition, the patch also protects the init process state to
> >> successfully get usable init coredump.
> >
> > Could you spell please?
> >
> > Does this connect to SIGNAL_GROUP_EXIT check? Do you mean that you want
> > to panic earlier, before other init's sub-threads exit?
>
> That is my understanding.
>
> As I understand it this patch has two purposes:
> 1. Avoid the BUG_ON in zap_pid_ns_processes when !CONFIG_PID_NS
> 2. panic as early as possible so exiting threads don't removing
> interesting debugging state.
Yes, this was my understanding too, but the changelog didn't look
clear to me.
And I'd say that it is not that we want to avoid BUG_ON() in
zap_pid_ns_processes() when !CONFIG_PID_NS, we want to avoid
zap_pid_ns_processes() in the root namespace, regardless of
CONFIG_PID_NS.
> It is a bit tricky to tell if the movement of the decrement of
> signal->live is safe.
Agreed, this was my concern. I see nothing wrong at first glance,
but I can easily miss something.
Oleg.
next prev parent reply other threads:[~2021-03-19 16:27 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 12:51 [PATCH V3] exit: trigger panic when global init has exited Qianli Zhao
2021-03-17 14:38 ` Oleg Nesterov
2021-03-18 2:47 ` qianli zhao
2021-03-18 18:04 ` Oleg Nesterov
2021-03-18 19:08 ` Eric W. Biederman
2021-03-19 6:33 ` qianli zhao
2021-03-19 16:34 ` Oleg Nesterov
2021-03-19 16:26 ` Oleg Nesterov [this message]
2021-03-21 16:00 ` qianli zhao
2021-03-22 17:07 ` Oleg Nesterov
2021-03-22 17:09 ` Oleg Nesterov
2021-03-19 5:08 ` qianli zhao
2021-03-19 16:32 ` Oleg Nesterov
2021-03-21 13:04 ` qianli zhao
2021-03-22 16:37 ` Oleg Nesterov
2021-03-23 3:14 ` qianli zhao
2021-03-23 9:00 ` Oleg Nesterov
2021-03-23 11:23 ` qianli zhao
2021-03-24 18:12 ` Oleg Nesterov
2021-03-25 3:00 ` qianli zhao
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