Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1646721

Re: [linux-next / tty] possible circular locking dependency detected

From Vegard Nossum <vegard.nossum@oracle.com>
Newsgroups linux.kernel
Subject Re: [linux-next / tty] possible circular locking dependency detected
Date 2017-05-22 12:40 +0200
Message-ID <tJSUP-4wq-47@gated-at.bofh.it> (permalink)
References <tJQgh-2Cc-3@gated-at.bofh.it> <tJSL7-4td-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On 05/22/17 12:24, Greg Kroah-Hartman wrote:
> On Mon, May 22, 2017 at 04:39:43PM +0900, Sergey Senozhatsky wrote:
>> Hello,
>>
>> [ 1274.378287] ======================================================
>> [ 1274.378289] WARNING: possible circular locking dependency detected
>> [ 1274.378290] 4.12.0-rc1-next-20170522-dbg-00007-gc09b2ab28b74-dirty #1317 Not tainted
>> [ 1274.378291] ------------------------------------------------------
>> [ 1274.378293] kworker/u8:5/111 is trying to acquire lock:
>> [ 1274.378294]  (&buf->lock){+.+...}, at: [<ffffffff812f2831>] tty_buffer_flush+0x34/0x88
>> [ 1274.378300]
>>                 but task is already holding lock:
>> [ 1274.378301]  (&o_tty->termios_rwsem/1){++++..}, at: [<ffffffff812ee5c7>] isig+0x47/0xd2
>> [ 1274.378307]
>>                 which lock already depends on the new lock.
>>

> Any hint as to what you were doing when this happened?
> 
> Does this also show up in 4.11?

It's my patch "tty: fix port buffer locking" :-/

At a glance, looks related to pty taking the lock on the other side in a
different order. I'll have a closer look.


Vegard

Back to linux.kernel | Previous | NextPrevious in thread | Find similar | Unroll thread


Thread

[linux-next / tty] possible circular locking dependency detected Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-05-22 09:50 +0200
  Re: [linux-next / tty] possible circular locking dependency detected Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-22 12:30 +0200
    Re: [linux-next / tty] possible circular locking dependency detected Jiri Slaby <jslaby@suse.cz> - 2017-05-22 12:30 +0200
    Re: [linux-next / tty] possible circular locking dependency detected Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-05-22 12:40 +0200
    Re: [linux-next / tty] possible circular locking dependency detected Vegard Nossum <vegard.nossum@oracle.com> - 2017-05-22 12:40 +0200

csiph-web