Messages in this thread | | | Subject | Re: [linux-next / tty] possible circular locking dependency detected | From | Vegard Nossum <> | Date | Mon, 29 May 2017 12:43:39 +0200 |
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On 05/22/17 12:27, Vegard Nossum wrote: > 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.
I can reproduce the lockdep report locally on v4.12-rc3. Looking at it now.
Vegard
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