From: Peter Zijlstra <peterz@infradead.org>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
Ingo Molnar <mingo@redhat.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>, LKML <linux-kernel@vger.kernel.org>,
J Freyensee <james_p_freyensee@linux.intel.com>,
syzkaller <syzkaller@googlegroups.com>,
Kostya Serebryany <kcc@google.com>,
Alexander Potapenko <glider@google.com>,
Sasha Levin <sasha.levin@oracle.com>,
Eric Dumazet <edumazet@google.com>
Subject: Re: tty: deadlock between n_tracerouter_receivebuf and flush_to_ldisc
Date: Wed, 20 Jan 2016 12:44:30 +0100 [thread overview]
Message-ID: <20160120114430.GA25010@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <CACT4Y+aP=F9fVC2q0vX4A=AhA8Mu54p7v9s8gbNh=JJJH3g8oA@mail.gmail.com>
On Wed, Jan 20, 2016 at 10:36:01AM +0100, Dmitry Vyukov wrote:
> +Peter, Ingo, can you please suggest a way to annotate this locking
> pattern to avoid lockdep false positive?
No, because I haven't a clue what the actual problem is.
The report is fairly clear on how:
routelock
&port->buf.lock/1
&o_tty->termios_rwsem/1
&buf->lock
gets established, and shows where we try:
&buf->lock
routelock
Which gives a circle, ergo deadlock.
Show which link is wrong and why, and I can suggest ways of annotating
that.
next prev parent reply other threads:[~2016-01-20 11:44 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-30 10:44 Dmitry Vyukov
2016-01-15 7:51 ` Dmitry Vyukov
2016-01-15 16:33 ` One Thousand Gnomes
2016-01-15 17:22 ` Dmitry Vyukov
2016-01-20 9:36 ` Dmitry Vyukov
2016-01-20 11:44 ` Peter Zijlstra [this message]
2016-01-20 11:54 ` Dmitry Vyukov
2016-01-20 12:07 ` Peter Zijlstra
2016-01-20 14:58 ` One Thousand Gnomes
2016-01-20 15:16 ` Dmitry Vyukov
2016-01-20 16:32 ` Peter Zijlstra
2016-01-20 2:09 ` J Freyensee
2016-01-20 12:47 ` Jiri Slaby
2016-01-20 13:02 ` Peter Zijlstra
2016-01-20 13:07 ` Dmitry Vyukov
2016-01-20 16:08 ` Peter Hurley
2016-01-20 20:47 ` Peter Hurley
2016-01-21 10:06 ` Dmitry Vyukov
2016-01-21 10:20 ` Peter Zijlstra
2016-01-21 17:51 ` Peter Hurley
2016-01-22 14:10 ` Dmitry Vyukov
2016-01-25 16:56 ` Peter Hurley
2016-01-21 17:43 ` Peter Hurley
2016-02-03 4:24 ` Peter Hurley
2016-02-03 17:32 ` Dmitry Vyukov
2016-02-03 19:09 ` Peter Hurley
2016-02-04 12:39 ` Dmitry Vyukov
2016-02-04 13:17 ` Dmitry Vyukov
2016-02-04 18:46 ` Peter Hurley
2016-02-04 18:48 ` Dmitry Vyukov
2016-02-05 21:22 ` Dmitry Vyukov
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