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From: Igor Zhbanov <i.zhbanov@omprussia.ru>
To: Oleg Nesterov <oleg@redhat.com>
Cc: <linux-trace-devel@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: Mutual debugging of 2 processes can stuck in unkillable stopped state
Date: Mon, 29 Mar 2021 20:44:41 +0300	[thread overview]
Message-ID: <c0131d23-fb09-7622-d51d-30e094d92136@omprussia.ru> (raw)
In-Reply-To: <20210329173848.GC24849@redhat.com>

Hi Oleg,

On 29.03.2021 20:38, Oleg Nesterov wrote:
> Hi Igor,
> 
> So. As expected, they sleep in EVENT_EXIT _after_ you have already
> sent SIGKILL.

Here is the processes stack before sending any signals to them:

izh@suse2:~> sudo cat /proc/1751/stack
[<0>] ptrace_stop+0x14e/0x260
[<0>] ptrace_do_notify+0x91/0xb0
[<0>] ptrace_notify+0x4e/0x70
[<0>] syscall_slow_exit_work+0x90/0x150
[<0>] do_syscall_64+0x129/0x1f0
[<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

izh@suse2:~> sudo cat /proc/1979/stack
[<0>] ptrace_stop+0x14e/0x260
[<0>] get_signal+0x4d5/0x840
[<0>] do_signal+0x30/0x6a0
[<0>] exit_to_usermode_loop+0x8b/0x120
[<0>] do_syscall_64+0x1c3/0x1f0
[<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

> Igor, thanks for your report, but (I think) this has nothing to do
> with mutual debugging. I'll return to this problem in a couple of
> days, I'm a bit busy right now.

Sorry for inexact description. I said it from the user perspective when
the processes are stopped and can't be killed. :-)

  reply	other threads:[~2021-03-29 17:45 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-29 15:28 Mutual debugging of 2 processes can stuck in unkillable stopped state Igor Zhbanov
2021-03-29 16:49 ` Oleg Nesterov
2021-03-29 17:01   ` Igor Zhbanov
2021-03-29 17:38     ` Oleg Nesterov
2021-03-29 17:44       ` Igor Zhbanov [this message]
2021-04-12  7:25         ` Igor Zhbanov
2021-04-13 17:17           ` Oleg Nesterov

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