From: "Gustavo F. Padovan" <gustavo@padovan.org>
To: linux-bluetooth@vger.kernel.org
Cc: marcel@holtmann.org, "Gustavo F. Padovan" <padovan@profusion.mobi>
Subject: [PATCH bluetooth-2.6] Bluetooth: Fix inconsistent lock state with RFCOMM
Date: Sat, 4 Sep 2010 06:16:21 -0300 [thread overview]
Message-ID: <1283591781-31412-1-git-send-email-gustavo@padovan.org> (raw)
From: Gustavo F. Padovan <padovan@profusion.mobi>
When receiving a rfcomm connection with the old dund deamon a
inconsistent lock state happens. That's because interrupts were already
disabled by l2cap_conn_start() when rfcomm_sk_state_change() try to lock
the spin_lock.
As result we may have a inconsistent lock state for l2cap_conn_start()
after rfcomm_sk_state_change() calls bh_lock_sock() and disable interrupts
as well.
[ 2833.151999]
[ 2833.151999] =================================
[ 2833.151999] [ INFO: inconsistent lock state ]
[ 2833.151999] 2.6.36-rc3 #2
[ 2833.151999] ---------------------------------
[ 2833.151999] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[ 2833.151999] krfcommd/2306 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 2833.151999] (slock-AF_BLUETOOTH){+.?...}, at: [<ffffffffa00bcb56>] rfcomm_sk_state_change+0x46/0x170 [rfcomm]
[ 2833.151999] {IN-SOFTIRQ-W} state was registered at:
[ 2833.151999] [<ffffffff81094346>] __lock_acquire+0x5b6/0x1560
[ 2833.151999] [<ffffffff8109534a>] lock_acquire+0x5a/0x70
[ 2833.151999] [<ffffffff81392b6c>] _raw_spin_lock+0x2c/0x40
[ 2833.151999] [<ffffffffa00a5092>] l2cap_conn_start+0x92/0x640 [l2cap]
[ 2833.151999] [<ffffffffa00a6a3f>] l2cap_sig_channel+0x6bf/0x1320 [l2cap]
[ 2833.151999] [<ffffffffa00a9173>] l2cap_recv_frame+0x133/0x770 [l2cap]
[ 2833.151999] [<ffffffffa00a997b>] l2cap_recv_acldata+0x1cb/0x390 [l2cap]
[ 2833.151999] [<ffffffffa000db4b>] hci_rx_task+0x2ab/0x450 [bluetooth]
[ 2833.151999] [<ffffffff8106b22b>] tasklet_action+0xcb/0xe0
[ 2833.151999] [<ffffffff8106b91e>] __do_softirq+0xae/0x150
[ 2833.151999] [<ffffffff8102bc0c>] call_softirq+0x1c/0x30
[ 2833.151999] [<ffffffff8102ddb5>] do_softirq+0x75/0xb0
[ 2833.151999] [<ffffffff8106b56d>] irq_exit+0x8d/0xa0
[ 2833.151999] [<ffffffff8104484b>] smp_apic_timer_interrupt+0x6b/0xa0
[ 2833.151999] [<ffffffff8102b6d3>] apic_timer_interrupt+0x13/0x20
[ 2833.151999] [<ffffffff81029dfa>] cpu_idle+0x5a/0xb0
[ 2833.151999] [<ffffffff81381ded>] rest_init+0xad/0xc0
[ 2833.151999] [<ffffffff817ebc4d>] start_kernel+0x2dd/0x2e8
[ 2833.151999] [<ffffffff817eb2e6>] x86_64_start_reservations+0xf6/0xfa
[ 2833.151999] [<ffffffff817eb3ce>] x86_64_start_kernel+0xe4/0xeb
[ 2833.151999] irq event stamp: 731
[ 2833.151999] hardirqs last enabled at (731): [<ffffffff8106b762>] local_bh_enable_ip+0x82/0xe0
[ 2833.151999] hardirqs last disabled at (729): [<ffffffff8106b93e>] __do_softirq+0xce/0x150
[ 2833.151999] softirqs last enabled at (730): [<ffffffff8106b96e>] __do_softirq+0xfe/0x150
[ 2833.151999] softirqs last disabled at (711): [<ffffffff8102bc0c>] call_softirq+0x1c/0x30
[ 2833.151999]
[ 2833.151999] other info that might help us debug this:
[ 2833.151999] 2 locks held by krfcommd/2306:
[ 2833.151999] #0: (rfcomm_mutex){+.+.+.}, at: [<ffffffffa00bb744>] rfcomm_run+0x174/0xb20 [rfcomm]
[ 2833.151999] #1: (&(&d->lock)->rlock){+.+...}, at: [<ffffffffa00b9223>] rfcomm_dlc_accept+0x53/0x100 [rfcomm]
[ 2833.151999]
[ 2833.151999] stack backtrace:
[ 2833.151999] Pid: 2306, comm: krfcommd Tainted: G W 2.6.36-rc3 #2
[ 2833.151999] Call Trace:
[ 2833.151999] [<ffffffff810928e1>] print_usage_bug+0x171/0x180
[ 2833.151999] [<ffffffff810936c3>] mark_lock+0x333/0x400
[ 2833.151999] [<ffffffff810943ca>] __lock_acquire+0x63a/0x1560
[ 2833.151999] [<ffffffff810948b5>] ? __lock_acquire+0xb25/0x1560
[ 2833.151999] [<ffffffff8109534a>] lock_acquire+0x5a/0x70
[ 2833.151999] [<ffffffffa00bcb56>] ? rfcomm_sk_state_change+0x46/0x170 [rfcomm]
[ 2833.151999] [<ffffffff81392b6c>] _raw_spin_lock+0x2c/0x40
[ 2833.151999] [<ffffffffa00bcb56>] ? rfcomm_sk_state_change+0x46/0x170 [rfcomm]
[ 2833.151999] [<ffffffffa00bcb56>] rfcomm_sk_state_change+0x46/0x170 [rfcomm]
[ 2833.151999] [<ffffffffa00b9239>] rfcomm_dlc_accept+0x69/0x100 [rfcomm]
[ 2833.151999] [<ffffffffa00b9a49>] rfcomm_check_accept+0x59/0xd0 [rfcomm]
[ 2833.151999] [<ffffffffa00bacab>] rfcomm_recv_frame+0x9fb/0x1320 [rfcomm]
[ 2833.151999] [<ffffffff813932bb>] ? _raw_spin_unlock_irqrestore+0x3b/0x60
[ 2833.151999] [<ffffffff81093acd>] ? trace_hardirqs_on_caller+0x13d/0x180
[ 2833.151999] [<ffffffff81093b1d>] ? trace_hardirqs_on+0xd/0x10
[ 2833.151999] [<ffffffffa00bb7f1>] rfcomm_run+0x221/0xb20 [rfcomm]
[ 2833.151999] [<ffffffff813905e7>] ? schedule+0x287/0x780
[ 2833.151999] [<ffffffffa00bb5d0>] ? rfcomm_run+0x0/0xb20 [rfcomm]
[ 2833.151999] [<ffffffff81081026>] kthread+0x96/0xa0
[ 2833.151999] [<ffffffff8102bb14>] kernel_thread_helper+0x4/0x10
[ 2833.151999] [<ffffffff813936bc>] ? restore_args+0x0/0x30
[ 2833.151999] [<ffffffff81080f90>] ? kthread+0x0/0xa0
[ 2833.151999] [<ffffffff8102bb10>] ? kernel_thread_helper+0x0/0x10
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
---
net/bluetooth/rfcomm/sock.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 44a6232..194b3a0 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -82,11 +82,14 @@ static void rfcomm_sk_data_ready(struct rfcomm_dlc *d, struct sk_buff *skb)
static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err)
{
struct sock *sk = d->owner, *parent;
+ unsigned long flags;
+
if (!sk)
return;
BT_DBG("dlc %p state %ld err %d", d, d->state, err);
+ local_irq_save(flags);
bh_lock_sock(sk);
if (err)
@@ -108,6 +111,7 @@ static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err)
}
bh_unlock_sock(sk);
+ local_irq_restore(flags);
if (parent && sock_flag(sk, SOCK_ZAPPED)) {
/* We have to drop DLC lock here, otherwise
--
1.7.1.1
reply other threads:[~2010-09-04 9:16 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=1283591781-31412-1-git-send-email-gustavo@padovan.org \
--to=gustavo@padovan.org \
--cc=linux-bluetooth@vger.kernel.org \
--cc=marcel@holtmann.org \
--cc=padovan@profusion.mobi \
/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.