From: Clemens Ladisch <clemens@ladisch.de>
To: Alan Cox <alan@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org
Subject: deadlock in vt_kbd_con_stop
Date: Tue, 01 May 2012 12:41:20 +0200 [thread overview]
Message-ID: <4F9FBDD0.7050504@ladisch.de> (raw)
Pressing the Scroll Lock key in the console stops scrolling rather permanently.
(Ctrl+S/Q works fine.)
=============================================
[ INFO: possible recursive locking detected ]
3.4.0-rc5+ #354 Not tainted
---------------------------------------------
swapper/5/0 is trying to acquire lock:
(kbd_event_lock){-.....}, at: [<ffffffff8127802c>] vt_kbd_con_stop+0x1a/0x57
but task is already holding lock:
(kbd_event_lock){-.....}, at: [<ffffffff81277a84>] kbd_event+0x29/0x5b7
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(kbd_event_lock);
lock(kbd_event_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by swapper/5/0:
#0: (&serio->lock){-.....}, at: [<ffffffff813abbd1>] serio_interrupt+0x24/0x7c
#1: (&(&dev->event_lock)->rlock#2){-.....}, at: [<ffffffff813b141a>] input_event+0x3a/0x7c
#2: (rcu_read_lock){.+.+..}, at: [<ffffffff813afc20>] input_pass_event+0x0/0x128
#3: (kbd_event_lock){-.....}, at: [<ffffffff81277a84>] kbd_event+0x29/0x5b7
stack backtrace:
Pid: 0, comm: swapper/5 Not tainted 3.4.0-rc5+ #354
Call Trace:
<IRQ> [<ffffffff81029562>] ? vprintk+0x3ac/0x404
[<ffffffff8106a3ed>] validate_chain+0x6ca/0xe6b
[<ffffffff8106a9d5>] ? validate_chain+0xcb2/0xe6b
[<ffffffff8106b417>] __lock_acquire+0x889/0x8fa
[<ffffffff8106b417>] ? __lock_acquire+0x889/0x8fa
[<ffffffff8106b4df>] lock_acquire+0x57/0x6d
[<ffffffff8127802c>] ? vt_kbd_con_stop+0x1a/0x57
[<ffffffff8148ddd8>] _raw_spin_lock_irqsave+0x46/0x58
[<ffffffff8127802c>] ? vt_kbd_con_stop+0x1a/0x57
[<ffffffff8127802c>] vt_kbd_con_stop+0x1a/0x57
[<ffffffff8127c0f5>] con_stop+0x26/0x28
[<ffffffff8126aad0>] stop_tty+0xa4/0xac
[<ffffffff81277823>] fn_hold+0x2a/0x2c
[<ffffffff812769d9>] k_spec+0x38/0x3a
[<ffffffff81277f7b>] kbd_event+0x520/0x5b7
[<ffffffff813afcde>] input_pass_event+0xbe/0x128
[<ffffffff813afc20>] ? input_handler_for_each_handle+0xcd/0xcd
[<ffffffff813b12e8>] input_handle_event+0x42a/0x439
[<ffffffff813b143b>] input_event+0x5b/0x7c
[<ffffffff813b7d8d>] atkbd_interrupt+0x50f/0x5de
[<ffffffff813abbed>] serio_interrupt+0x40/0x7c
[<ffffffff813ac992>] i8042_interrupt+0x289/0x2a3
[<ffffffff8107e594>] handle_irq_event_percpu+0x34/0x133
[<ffffffff8107e6cf>] handle_irq_event+0x3c/0x5c
[<ffffffff81080c4b>] handle_edge_irq+0xc7/0xec
[<ffffffff8100378e>] handle_irq+0x122/0x130
[<ffffffff810459be>] ? atomic_notifier_call_chain+0xf/0x11
[<ffffffff81002eb3>] do_IRQ+0x48/0xaf
[<ffffffff8148e6ac>] common_interrupt+0x6c/0x6c
<EOI> [<ffffffff81008ff0>] ? default_idle+0x29/0x43
[<ffffffff81008fee>] ? default_idle+0x27/0x43
[<ffffffff81009155>] amd_e400_idle+0xcd/0xf4
[<ffffffff81009289>] cpu_idle+0x73/0xb8
[<ffffffff8148674c>] start_secondary+0x225/0x227
next reply other threads:[~2012-05-01 10:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-01 10:41 Clemens Ladisch [this message]
2012-05-01 12:22 ` deadlock in vt_kbd_con_stop Jiri Kosina
2012-05-01 12:31 ` Alan Cox
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4F9FBDD0.7050504@ladisch.de \
--to=clemens@ladisch.de \
--cc=alan@linux.intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.