From: Tejun Heo <tj@kernel.org>
To: Andrew Vagin <avagin@openvz.org>
Cc: linux-kernel@vger.kernel.org, Oleg Nesterov <oleg@redhat.com>,
Roland McGrath <roland@redhat.com>,
Cyrill Gorcunov <gorcunov@openvz.org>,
Pavel Emelyanov <xemul@parallels.com>
Subject: Re: [PATCH] ptrace: add ability to get clear_tid_address
Date: Fri, 3 Feb 2012 08:25:19 -0800 [thread overview]
Message-ID: <20120203162519.GB805@google.com> (raw)
In-Reply-To: <1328267483-3225342-1-git-send-email-avagin@openvz.org>
On Fri, Feb 03, 2012 at 02:11:23PM +0300, Andrew Vagin wrote:
> Zero is written at clear_tid_address, when the process exits.
> This functionality is used by pthread_join().
>
> sys_set_tid_address() changes this address for current task.
>
> Before this patch clear_tid_address could not be got from user space.
> I want to dump a full state of a task, so I need this address.
> Also I think it may be useful for debugging a multithreading program.
>
> I am not sure that ptrace is suitable place. It may be added in prctl,
> but I think it's a bit useless and strange. I can't image a real
> situation (avoid checkpointing) when a thread will want to get own
> clear_tid_address from itself, this address is used by parent ussually.
>
> Signed-off-by: Andrew Vagin <avagin@openvz.org>
Ummm... this really doesn't fit in ptrace. Cyrill, why not put it
together with other params you're exporting?
Thanks.
--
tejun
next prev parent reply other threads:[~2012-02-03 16:25 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-03 11:11 [PATCH] ptrace: add ability to get clear_tid_address Andrew Vagin
2012-02-03 16:25 ` Tejun Heo [this message]
2012-02-03 16:30 ` Cyrill Gorcunov
2012-02-03 16:41 ` Oleg Nesterov
2012-02-03 16:54 ` Cyrill Gorcunov
2012-02-03 16:45 ` Pavel Emelyanov
2012-02-03 16:51 ` Oleg Nesterov
2012-02-07 20:07 ` Pedro Alves
2012-02-07 20:56 ` Cyrill Gorcunov
2012-02-07 21:15 ` Pedro Alves
2012-02-07 21:51 ` Cyrill Gorcunov
2012-02-08 12:30 ` Pedro Alves
2012-02-08 12:42 ` Cyrill Gorcunov
2012-02-08 17:31 ` Oleg Nesterov
2012-02-08 18:04 ` Pedro Alves
2012-02-08 19:02 ` Oleg Nesterov
2012-02-08 19:20 ` Cyrill Gorcunov
2012-02-08 19:21 ` Jan Kratochvil
2012-02-08 19:42 ` Pedro Alves
2012-02-08 13:41 ` Andrew Vagin
2012-02-08 18:12 ` Jan Kratochvil
2012-02-10 3:02 ` Jamie Lokier
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