From: Oleg Nesterov <oleg@redhat.com>
To: qianli zhao <zhaoqianligood@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.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 17:34:43 +0100 [thread overview]
Message-ID: <20210319163442.GC19971@redhat.com> (raw)
In-Reply-To: <CAPx_LQHahNDvUkv08RZgUvbKZtdHNaSNRA1XqVDkNiwv5D=fXg@mail.gmail.com>
On 03/19, qianli zhao wrote:
>
> I will think about the risks of movement of the decrement of
> signal->live before exit_signal().
> If is difficult to judge movement of the decrement of signal->live is
> safe,how about only test 'signal->live==1' not use group_dead?
>
> Such as:
> diff --git a/kernel/exit.c b/kernel/exit.c
> index 04029e3..87f3595 100644
> --- a/kernel/exit.c
> +++ b/kernel/exit.c
> @@ -767,6 +767,17 @@ void __noreturn do_exit(long code)
> validate_creds_for_do_exit(tsk);
>
> /*
> + * If global init has exited,
> + * panic immediately to get a useable coredump.
> + */
> + if (unlikely(is_global_init(tsk) &&
> + ((atomic_read(&tsk->signal->live) == 1) || /*current is
> last init thread*/
Just suppose signal->live == 2 and both init's sub-threads exit at the
same time. They both can see signal->live == 2, panic() won't be called.
Oleg.
next prev parent reply other threads:[~2021-03-19 16:35 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 [this message]
2021-03-19 16:26 ` Oleg Nesterov
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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