From: Larry Finger <Larry.Finger@lwfinger.net>
To: LKML <linux-kernel@vger.kernel.org>
Subject: Lockdep warning from 3.4-gitX
Date: Fri, 25 May 2012 22:18:24 -0500 [thread overview]
Message-ID: <4FC04B80.3000007@lwfinger.net> (raw)
A newly built mainline kernel that git-describe shows as v3.4-7895-g1937f4f has
the following lockdep log splat:
[ 69.013395] =============================================
[ 69.013397] [ INFO: possible recursive locking detected ]
[ 69.013401] 3.4.0-Linus-07895-g1937f4f #148 Not tainted
[ 69.013403] ---------------------------------------------
[ 69.013405] bash/3631 is trying to acquire lock:
[ 69.013415] (&tty->legacy_mutex){+.+.+.}, at: [<ffffffff81382662>]
tty_lock+0x32/0x70
[ 69.013417]
[ 69.013417] but task is already holding lock:
[ 69.013423] (&tty->legacy_mutex){+.+.+.}, at: [<ffffffff81382662>]
tty_lock+0x32/0x70
[ 69.013425]
[ 69.013425] other info that might help us debug this:
[ 69.013427] Possible unsafe locking scenario:
[ 69.013427]
[ 69.013429] CPU0
[ 69.013430] ----
[ 69.013433] lock(&tty->legacy_mutex);
[ 69.013435] lock(&tty->legacy_mutex);
[ 69.013437]
[ 69.013437] *** DEADLOCK ***
[ 69.013437]
[ 69.013439] May be due to missing lock nesting notation
[ 69.013439]
[ 69.013442] 2 locks held by bash/3631:
[ 69.013449] #0: (tty_mutex){+.+.+.}, at: [<ffffffff812577e1>]
tty_release+0x191/0x580
[ 69.013456] #1: (&tty->legacy_mutex){+.+.+.}, at: [<ffffffff81382662>]
tty_lock+0x32/0x70
[ 69.013457]
[ 69.013457] stack backtrace:
[ 69.013461] Pid: 3631, comm: bash Not tainted 3.4.0-Linus-07895-g1937f4f #148
[ 69.013463] Call Trace:
[ 69.013468] [<ffffffff8108c3d8>] __lock_acquire+0xee8/0x1c80
[ 69.013472] [<ffffffff81382662>] ? tty_lock+0x32/0x70
[ 69.013476] [<ffffffff8108d735>] lock_acquire+0x95/0x150
[ 69.013479] [<ffffffff81382662>] ? tty_lock+0x32/0x70
[ 69.013483] [<ffffffff8137f933>] ? mutex_lock_nested+0x273/0x350
[ 69.013486] [<ffffffff8137f72b>] mutex_lock_nested+0x6b/0x350
[ 69.013490] [<ffffffff81382662>] ? tty_lock+0x32/0x70
[ 69.013493] [<ffffffff8108e185>] ? trace_hardirqs_on_caller+0x105/0x190
[ 69.013497] [<ffffffff81382662>] tty_lock+0x32/0x70
[ 69.013500] [<ffffffff813826f5>] tty_lock_pair+0x55/0x5c
[ 69.013504] [<ffffffff812577ec>] tty_release+0x19c/0x580
[ 69.013509] [<ffffffff8112c3a5>] fput+0xf5/0x260
[ 69.013513] [<ffffffff81382886>] ? retint_swapgs+0xe/0x13
[ 69.013517] [<ffffffff81128846>] filp_close+0x56/0x80
[ 69.013520] [<ffffffff8112890b>] sys_close+0x9b/0x100
[ 69.013525] [<ffffffff81382fe2>] system_call_fastpath+0x16/0x1b
Thanks,
Larry
next reply other threads:[~2012-05-26 3:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-26 3:18 Larry Finger [this message]
2012-05-27 12:23 ` Lockdep warning from 3.4-gitX Greg KH
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