linux/include/net/bluetooth/l2cap.h

948 lines
22 KiB

Bluetooth: EFS: implement L2CAP config pending state Add L2CAP Config Pending state for EFS. Currently after receiving Config Response Pending respond with Config Response Success. ... > ACL data: handle 1 flags 0x02 dlen 16 L2CAP(s): Connect rsp: dcid 0x0040 scid 0x0040 result 0 status 0 Connection successful > ACL data: handle 1 flags 0x02 dlen 45 L2CAP(s): Config req: dcid 0x0040 flags 0x00 clen 33 RFC 0x03 (Enhanced Retransmission, TxWin 63, MaxTx 3, RTo 0, MTo 0, MPS 1009) EFS (Id 0x01, SerType Best Effort, MaxSDU 0xffff, SDUitime 0xffffffff, AccLat 0xffffffff, FlushTO 0x0000ffff) < ACL data: handle 1 flags 0x00 dlen 45 L2CAP(s): Config req: dcid 0x0040 flags 0x00 clen 33 RFC 0x03 (Enhanced Retransmission, TxWin 63, MaxTx 3, RTo 0, MTo 0, MPS 498) EFS (Id 0x01, SerType Best Effort, MaxSDU 0xffff, SDUitime 0xffffffff, AccLat 0xffffffff, FlushTO 0x0000ffff) < ACL data: handle 1 flags 0x00 dlen 47 L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 4 clen 33 Pending MTU 672 RFC 0x03 (Enhanced Retransmission, TxWin 63, MaxTx 3, RTo 2000, MTo 12000, MPS 498) EFS (Id 0x01, SerType Best Effort, MaxSDU 0xffff, SDUitime 0xffffffff, AccLat 0xffffffff, FlushTO 0x0000ffff) > ACL data: handle 1 flags 0x02 dlen 47 L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 4 clen 33 Pending MTU 672 RFC 0x03 (Enhanced Retransmission, TxWin 63, MaxTx 3, RTo 2000, MTo 12000, MPS 498) EFS (Id 0x01, SerType Best Effort, MaxSDU 0xffff, SDUitime 0xffffffff, AccLat 0xffffffff, FlushTO 0x0000ffff) > ACL data: handle 1 flags 0x02 dlen 14 L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 0 clen 0 Success < ACL data: handle 1 flags 0x00 dlen 14 L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 0 clen 0 Success < ACL data: handle 1 flags 0x00 dlen 510 L2CAP(d): cid 0x0040 len 506 ext_ctrl 0x00010000 fcs 0xebe0 [psm 4113] I-frame: Start (len 672) TxSeq 0 ReqSeq 0 ... Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com> Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-10-17 14:35:32 +03:00
Bluetooth: Ask upper layers for HCI disconnect reason Some of the qualification tests demand that in case of failures in L2CAP the HCI disconnect should indicate a reason why L2CAP fails. This is a bluntly layer violation since multiple L2CAP connections could be using the same ACL and thus forcing a disconnect reason is not a good idea. To comply with the Bluetooth test specification, the disconnect reason is now stored in the L2CAP connection structure and every time a new L2CAP channel is added it will set back to its default. So only in the case where the L2CAP channel with the disconnect reason is really the last one, it will propagated to the HCI layer. The HCI layer has been extended with a disconnect indication that allows it to ask upper layers for a disconnect reason. The upper layer must not support this callback and in that case it will nicely default to the existing behavior. If an upper layer like L2CAP can provide a disconnect reason that one will be used to disconnect the ACL or SCO link. No modification to the ACL disconnect timeout have been made. So in case of Linux to Linux connection the initiator will disconnect the ACL link before the acceptor side can signal the specific disconnect reason. That is perfectly fine since Linux doesn't make use of this value anyway. The L2CAP layer has a perfect valid error code for rejecting connection due to a security violation. It is unclear why the Bluetooth specification insists on having specific HCI disconnect reason. Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2009-02-12 14:02:50 +01:00
Bluetooth: l2cap: add l2cap_user sub-modules Several sub-modules like HIDP, rfcomm, ... need to track l2cap connections. The l2cap_conn->hcon->dev object is used as parent for sysfs devices so the sub-modules need to be notified when the hci_conn object is removed from sysfs. As submodules normally use the l2cap layer, the l2cap_user objects are registered there instead of on the underlying hci_conn object. This avoids any direct dependency on the HCI layer and lets the l2cap core handle any specifics. This patch introduces l2cap_user objects which contain a "probe" and "remove" callback. You can register them on any l2cap_conn object and if it is active, the "probe" callback will get called. Otherwise, an error is returned. The l2cap_conn object will call your "remove" callback directly before it is removed from user-space. This allows you to remove your submodules _before_ the parent l2cap_conn and hci_conn object is removed. At any time you can asynchronously unregister your l2cap_user object if your submodule vanishes before the l2cap_conn object does. There is no way around l2cap_user. If we want wire-protocols in the kernel, we always want the hci_conn object as parent in the sysfs tree. We cannot use a channel here since we might need multiple channels for a single protocol. But the problem is, we _must_ get notified when an l2cap_conn object is removed. We cannot use reference-counting for object-removal! This is not how it works. If a hardware is removed, we should immediately remove the object from sysfs. Any other behavior would be inconsistent with the rest of the system. Also note that device_del() might sleep, but it doesn't wait for user-space or block very long. It only _unlinks_ the object from sysfs and the whole device-tree. Everything else is handled by ref-counts! This is exactly what the other sub-modules must do: unlink their devices when the "remove" l2cap_user callback is called. They should not do any cleanup or synchronous shutdowns. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
2013-04-06 20:28:45 +02:00
Bluetooth: EFS: implement L2CAP config pending state Add L2CAP Config Pending state for EFS. Currently after receiving Config Response Pending respond with Config Response Success. ... > ACL data: handle 1 flags 0x02 dlen 16 L2CAP(s): Connect rsp: dcid 0x0040 scid 0x0040 result 0 status 0 Connection successful > ACL data: handle 1 flags 0x02 dlen 45 L2CAP(s): Config req: dcid 0x0040 flags 0x00 clen 33 RFC 0x03 (Enhanced Retransmission, TxWin 63, MaxTx 3, RTo 0, MTo 0, MPS 1009) EFS (Id 0x01, SerType Best Effort, MaxSDU 0xffff, SDUitime 0xffffffff, AccLat 0xffffffff, FlushTO 0x0000ffff) < ACL data: handle 1 flags 0x00 dlen 45 L2CAP(s): Config req: dcid 0x0040 flags 0x00 clen 33 RFC 0x03 (Enhanced Retransmission, TxWin 63, MaxTx 3, RTo 0, MTo 0, MPS 498) EFS (Id 0x01, SerType Best Effort, MaxSDU 0xffff, SDUitime 0xffffffff, AccLat 0xffffffff, FlushTO 0x0000ffff) < ACL data: handle 1 flags 0x00 dlen 47 L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 4 clen 33 Pending MTU 672 RFC 0x03 (Enhanced Retransmission, TxWin 63, MaxTx 3, RTo 2000, MTo 12000, MPS 498) EFS (Id 0x01, SerType Best Effort, MaxSDU 0xffff, SDUitime 0xffffffff, AccLat 0xffffffff, FlushTO 0x0000ffff) > ACL data: handle 1 flags 0x02 dlen 47 L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 4 clen 33 Pending MTU 672 RFC 0x03 (Enhanced Retransmission, TxWin 63, MaxTx 3, RTo 2000, MTo 12000, MPS 498) EFS (Id 0x01, SerType Best Effort, MaxSDU 0xffff, SDUitime 0xffffffff, AccLat 0xffffffff, FlushTO 0x0000ffff) > ACL data: handle 1 flags 0x02 dlen 14 L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 0 clen 0 Success < ACL data: handle 1 flags 0x00 dlen 14 L2CAP(s): Config rsp: scid 0x0040 flags 0x00 result 0 clen 0 Success < ACL data: handle 1 flags 0x00 dlen 510 L2CAP(d): cid 0x0040 len 506 ext_ctrl 0x00010000 fcs 0xebe0 [psm 4113] I-frame: Start (len 672) TxSeq 0 ReqSeq 0 ... Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com> Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-10-17 14:35:32 +03:00
Bluetooth: Fix deadlocks with sock lock and L2CAP timers locks When cancelling a delayed work (timer) in L2CAP we can not sleep holding the sock mutex otherwise we might deadlock with an L2CAP timer handler. This is possible because RX/TX and L2CAP timers run in different workqueues. The scenario below illustrates the problem. Thus we are now avoiding to sleep on the timers locks. ====================================================== [ INFO: possible circular locking dependency detected ] 3.1.0-05270-ga978dc7-dirty #239 ------------------------------------------------------- kworker/1:1/873 is trying to acquire lock: (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}, at: [<ffffffffa002ceac>] l2cap_chan_timeout+0x3c/0xe0 [bluetooth] but task is already holding lock: ((&(&chan->chan_timer)->work)){+.+...}, at: [<ffffffff81051a86>] process_one_work+0x126/0x450 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 ((&(&chan->chan_timer)->work)){+.+...}: [<ffffffff8106b276>] check_prevs_add+0xf6/0x170 [<ffffffff8106b903>] validate_chain+0x613/0x790 [<ffffffff8106dfee>] __lock_acquire+0x4be/0xac0 [<ffffffff8106ec2d>] lock_acquire+0x8d/0xb0 [<ffffffff81052a6f>] wait_on_work+0x4f/0x160 [<ffffffff81052ca3>] __cancel_work_timer+0x73/0x80 [<ffffffff81052cbd>] cancel_delayed_work_sync+0xd/0x10 [<ffffffffa002f2ed>] l2cap_chan_connect+0x22d/0x470 [bluetooth] [<ffffffffa002fb51>] l2cap_sock_connect+0xb1/0x140 [bluetooth] [<ffffffff8130811b>] kernel_connect+0xb/0x10 [<ffffffffa00cf98a>] rfcomm_session_create+0x12a/0x1c0 [rfcomm] [<ffffffffa00cfbe7>] __rfcomm_dlc_open+0x1c7/0x240 [rfcomm] [<ffffffffa00d07c2>] rfcomm_dlc_open+0x42/0x70 [rfcomm] [<ffffffffa00d3b03>] rfcomm_sock_connect+0x103/0x150 [rfcomm] [<ffffffff8130bd7e>] sys_connect+0xae/0xc0 [<ffffffff813368d2>] compat_sys_socketcall+0xb2/0x220 [<ffffffff813b2089>] sysenter_dispatch+0x7/0x30 -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}: [<ffffffff8106b16d>] check_prev_add+0x6cd/0x6e0 [<ffffffff8106b276>] check_prevs_add+0xf6/0x170 [<ffffffff8106b903>] validate_chain+0x613/0x790 [<ffffffff8106dfee>] __lock_acquire+0x4be/0xac0 [<ffffffff8106ec2d>] lock_acquire+0x8d/0xb0 [<ffffffff8130d91a>] lock_sock_nested+0x8a/0xa0 [<ffffffffa002ceac>] l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff81051ae4>] process_one_work+0x184/0x450 [<ffffffff8105276e>] worker_thread+0x15e/0x340 [<ffffffff81057bb6>] kthread+0x96/0xa0 [<ffffffff813b1ef4>] kernel_thread_helper+0x4/0x10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((&(&chan->chan_timer)->work)); lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); lock((&(&chan->chan_timer)->work)); lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); *** DEADLOCK *** 2 locks held by kworker/1:1/873: #0: (events){.+.+.+}, at: [<ffffffff81051a86>] process_one_work+0x126/0x450 #1: ((&(&chan->chan_timer)->work)){+.+...}, at: [<ffffffff81051a86>] process_one_work+0x126/0x450 stack backtrace: Pid: 873, comm: kworker/1:1 Not tainted 3.1.0-05270-ga978dc7-dirty #239 Call Trace: [<ffffffff813a0f6e>] print_circular_bug+0xd2/0xe3 [<ffffffff8106b16d>] check_prev_add+0x6cd/0x6e0 [<ffffffff8106b276>] check_prevs_add+0xf6/0x170 [<ffffffff8106b903>] validate_chain+0x613/0x790 [<ffffffff8106dfee>] __lock_acquire+0x4be/0xac0 [<ffffffff8130d8f6>] ? lock_sock_nested+0x66/0xa0 [<ffffffff8106ea30>] ? lock_release_nested+0x100/0x110 [<ffffffff8130d8f6>] ? lock_sock_nested+0x66/0xa0 [<ffffffff8106ec2d>] lock_acquire+0x8d/0xb0 [<ffffffffa002ceac>] ? l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff8130d91a>] lock_sock_nested+0x8a/0xa0 [<ffffffffa002ceac>] ? l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff81051a86>] ? process_one_work+0x126/0x450 [<ffffffffa002ceac>] l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff81051ae4>] process_one_work+0x184/0x450 [<ffffffff81051a86>] ? process_one_work+0x126/0x450 [<ffffffffa002ce70>] ? l2cap_security_cfm+0x4e0/0x4e0 [bluetooth] [<ffffffff8105276e>] worker_thread+0x15e/0x340 [<ffffffff81052610>] ? manage_workers+0x110/0x110 [<ffffffff81057bb6>] kthread+0x96/0xa0 [<ffffffff813b1ef4>] kernel_thread_helper+0x4/0x10 [<ffffffff813af69d>] ? retint_restore_args+0xe/0xe [<ffffffff81057b20>] ? __init_kthread_worker+0x70/0x70 [<ffffffff813b1ef0>] ? gs_change+0xb/0xb Signed-off-by: Ulisses Furquim <ulisses@profusion.mobi> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-12-21 20:02:36 -02:00
Bluetooth: Fix deadlocks with sock lock and L2CAP timers locks When cancelling a delayed work (timer) in L2CAP we can not sleep holding the sock mutex otherwise we might deadlock with an L2CAP timer handler. This is possible because RX/TX and L2CAP timers run in different workqueues. The scenario below illustrates the problem. Thus we are now avoiding to sleep on the timers locks. ====================================================== [ INFO: possible circular locking dependency detected ] 3.1.0-05270-ga978dc7-dirty #239 ------------------------------------------------------- kworker/1:1/873 is trying to acquire lock: (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}, at: [<ffffffffa002ceac>] l2cap_chan_timeout+0x3c/0xe0 [bluetooth] but task is already holding lock: ((&(&chan->chan_timer)->work)){+.+...}, at: [<ffffffff81051a86>] process_one_work+0x126/0x450 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 ((&(&chan->chan_timer)->work)){+.+...}: [<ffffffff8106b276>] check_prevs_add+0xf6/0x170 [<ffffffff8106b903>] validate_chain+0x613/0x790 [<ffffffff8106dfee>] __lock_acquire+0x4be/0xac0 [<ffffffff8106ec2d>] lock_acquire+0x8d/0xb0 [<ffffffff81052a6f>] wait_on_work+0x4f/0x160 [<ffffffff81052ca3>] __cancel_work_timer+0x73/0x80 [<ffffffff81052cbd>] cancel_delayed_work_sync+0xd/0x10 [<ffffffffa002f2ed>] l2cap_chan_connect+0x22d/0x470 [bluetooth] [<ffffffffa002fb51>] l2cap_sock_connect+0xb1/0x140 [bluetooth] [<ffffffff8130811b>] kernel_connect+0xb/0x10 [<ffffffffa00cf98a>] rfcomm_session_create+0x12a/0x1c0 [rfcomm] [<ffffffffa00cfbe7>] __rfcomm_dlc_open+0x1c7/0x240 [rfcomm] [<ffffffffa00d07c2>] rfcomm_dlc_open+0x42/0x70 [rfcomm] [<ffffffffa00d3b03>] rfcomm_sock_connect+0x103/0x150 [rfcomm] [<ffffffff8130bd7e>] sys_connect+0xae/0xc0 [<ffffffff813368d2>] compat_sys_socketcall+0xb2/0x220 [<ffffffff813b2089>] sysenter_dispatch+0x7/0x30 -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}: [<ffffffff8106b16d>] check_prev_add+0x6cd/0x6e0 [<ffffffff8106b276>] check_prevs_add+0xf6/0x170 [<ffffffff8106b903>] validate_chain+0x613/0x790 [<ffffffff8106dfee>] __lock_acquire+0x4be/0xac0 [<ffffffff8106ec2d>] lock_acquire+0x8d/0xb0 [<ffffffff8130d91a>] lock_sock_nested+0x8a/0xa0 [<ffffffffa002ceac>] l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff81051ae4>] process_one_work+0x184/0x450 [<ffffffff8105276e>] worker_thread+0x15e/0x340 [<ffffffff81057bb6>] kthread+0x96/0xa0 [<ffffffff813b1ef4>] kernel_thread_helper+0x4/0x10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((&(&chan->chan_timer)->work)); lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); lock((&(&chan->chan_timer)->work)); lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); *** DEADLOCK *** 2 locks held by kworker/1:1/873: #0: (events){.+.+.+}, at: [<ffffffff81051a86>] process_one_work+0x126/0x450 #1: ((&(&chan->chan_timer)->work)){+.+...}, at: [<ffffffff81051a86>] process_one_work+0x126/0x450 stack backtrace: Pid: 873, comm: kworker/1:1 Not tainted 3.1.0-05270-ga978dc7-dirty #239 Call Trace: [<ffffffff813a0f6e>] print_circular_bug+0xd2/0xe3 [<ffffffff8106b16d>] check_prev_add+0x6cd/0x6e0 [<ffffffff8106b276>] check_prevs_add+0xf6/0x170 [<ffffffff8106b903>] validate_chain+0x613/0x790 [<ffffffff8106dfee>] __lock_acquire+0x4be/0xac0 [<ffffffff8130d8f6>] ? lock_sock_nested+0x66/0xa0 [<ffffffff8106ea30>] ? lock_release_nested+0x100/0x110 [<ffffffff8130d8f6>] ? lock_sock_nested+0x66/0xa0 [<ffffffff8106ec2d>] lock_acquire+0x8d/0xb0 [<ffffffffa002ceac>] ? l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff8130d91a>] lock_sock_nested+0x8a/0xa0 [<ffffffffa002ceac>] ? l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff81051a86>] ? process_one_work+0x126/0x450 [<ffffffffa002ceac>] l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff81051ae4>] process_one_work+0x184/0x450 [<ffffffff81051a86>] ? process_one_work+0x126/0x450 [<ffffffffa002ce70>] ? l2cap_security_cfm+0x4e0/0x4e0 [bluetooth] [<ffffffff8105276e>] worker_thread+0x15e/0x340 [<ffffffff81052610>] ? manage_workers+0x110/0x110 [<ffffffff81057bb6>] kthread+0x96/0xa0 [<ffffffff813b1ef4>] kernel_thread_helper+0x4/0x10 [<ffffffff813af69d>] ? retint_restore_args+0xe/0xe [<ffffffff81057b20>] ? __init_kthread_worker+0x70/0x70 [<ffffffff813b1ef0>] ? gs_change+0xb/0xb Signed-off-by: Ulisses Furquim <ulisses@profusion.mobi> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-12-21 20:02:36 -02:00
Bluetooth: Fix deadlocks with sock lock and L2CAP timers locks When cancelling a delayed work (timer) in L2CAP we can not sleep holding the sock mutex otherwise we might deadlock with an L2CAP timer handler. This is possible because RX/TX and L2CAP timers run in different workqueues. The scenario below illustrates the problem. Thus we are now avoiding to sleep on the timers locks. ====================================================== [ INFO: possible circular locking dependency detected ] 3.1.0-05270-ga978dc7-dirty #239 ------------------------------------------------------- kworker/1:1/873 is trying to acquire lock: (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}, at: [<ffffffffa002ceac>] l2cap_chan_timeout+0x3c/0xe0 [bluetooth] but task is already holding lock: ((&(&chan->chan_timer)->work)){+.+...}, at: [<ffffffff81051a86>] process_one_work+0x126/0x450 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 ((&(&chan->chan_timer)->work)){+.+...}: [<ffffffff8106b276>] check_prevs_add+0xf6/0x170 [<ffffffff8106b903>] validate_chain+0x613/0x790 [<ffffffff8106dfee>] __lock_acquire+0x4be/0xac0 [<ffffffff8106ec2d>] lock_acquire+0x8d/0xb0 [<ffffffff81052a6f>] wait_on_work+0x4f/0x160 [<ffffffff81052ca3>] __cancel_work_timer+0x73/0x80 [<ffffffff81052cbd>] cancel_delayed_work_sync+0xd/0x10 [<ffffffffa002f2ed>] l2cap_chan_connect+0x22d/0x470 [bluetooth] [<ffffffffa002fb51>] l2cap_sock_connect+0xb1/0x140 [bluetooth] [<ffffffff8130811b>] kernel_connect+0xb/0x10 [<ffffffffa00cf98a>] rfcomm_session_create+0x12a/0x1c0 [rfcomm] [<ffffffffa00cfbe7>] __rfcomm_dlc_open+0x1c7/0x240 [rfcomm] [<ffffffffa00d07c2>] rfcomm_dlc_open+0x42/0x70 [rfcomm] [<ffffffffa00d3b03>] rfcomm_sock_connect+0x103/0x150 [rfcomm] [<ffffffff8130bd7e>] sys_connect+0xae/0xc0 [<ffffffff813368d2>] compat_sys_socketcall+0xb2/0x220 [<ffffffff813b2089>] sysenter_dispatch+0x7/0x30 -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}: [<ffffffff8106b16d>] check_prev_add+0x6cd/0x6e0 [<ffffffff8106b276>] check_prevs_add+0xf6/0x170 [<ffffffff8106b903>] validate_chain+0x613/0x790 [<ffffffff8106dfee>] __lock_acquire+0x4be/0xac0 [<ffffffff8106ec2d>] lock_acquire+0x8d/0xb0 [<ffffffff8130d91a>] lock_sock_nested+0x8a/0xa0 [<ffffffffa002ceac>] l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff81051ae4>] process_one_work+0x184/0x450 [<ffffffff8105276e>] worker_thread+0x15e/0x340 [<ffffffff81057bb6>] kthread+0x96/0xa0 [<ffffffff813b1ef4>] kernel_thread_helper+0x4/0x10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((&(&chan->chan_timer)->work)); lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); lock((&(&chan->chan_timer)->work)); lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); *** DEADLOCK *** 2 locks held by kworker/1:1/873: #0: (events){.+.+.+}, at: [<ffffffff81051a86>] process_one_work+0x126/0x450 #1: ((&(&chan->chan_timer)->work)){+.+...}, at: [<ffffffff81051a86>] process_one_work+0x126/0x450 stack backtrace: Pid: 873, comm: kworker/1:1 Not tainted 3.1.0-05270-ga978dc7-dirty #239 Call Trace: [<ffffffff813a0f6e>] print_circular_bug+0xd2/0xe3 [<ffffffff8106b16d>] check_prev_add+0x6cd/0x6e0 [<ffffffff8106b276>] check_prevs_add+0xf6/0x170 [<ffffffff8106b903>] validate_chain+0x613/0x790 [<ffffffff8106dfee>] __lock_acquire+0x4be/0xac0 [<ffffffff8130d8f6>] ? lock_sock_nested+0x66/0xa0 [<ffffffff8106ea30>] ? lock_release_nested+0x100/0x110 [<ffffffff8130d8f6>] ? lock_sock_nested+0x66/0xa0 [<ffffffff8106ec2d>] lock_acquire+0x8d/0xb0 [<ffffffffa002ceac>] ? l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff8130d91a>] lock_sock_nested+0x8a/0xa0 [<ffffffffa002ceac>] ? l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff81051a86>] ? process_one_work+0x126/0x450 [<ffffffffa002ceac>] l2cap_chan_timeout+0x3c/0xe0 [bluetooth] [<ffffffff81051ae4>] process_one_work+0x184/0x450 [<ffffffff81051a86>] ? process_one_work+0x126/0x450 [<ffffffffa002ce70>] ? l2cap_security_cfm+0x4e0/0x4e0 [bluetooth] [<ffffffff8105276e>] worker_thread+0x15e/0x340 [<ffffffff81052610>] ? manage_workers+0x110/0x110 [<ffffffff81057bb6>] kthread+0x96/0xa0 [<ffffffff813b1ef4>] kernel_thread_helper+0x4/0x10 [<ffffffff813af69d>] ? retint_restore_args+0xe/0xe [<ffffffff81057b20>] ? __init_kthread_worker+0x70/0x70 [<ffffffff813b1ef0>] ? gs_change+0xb/0xb Signed-off-by: Ulisses Furquim <ulisses@profusion.mobi> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-12-21 20:02:36 -02:00
Bluetooth: l2cap: add l2cap_user sub-modules Several sub-modules like HIDP, rfcomm, ... need to track l2cap connections. The l2cap_conn->hcon->dev object is used as parent for sysfs devices so the sub-modules need to be notified when the hci_conn object is removed from sysfs. As submodules normally use the l2cap layer, the l2cap_user objects are registered there instead of on the underlying hci_conn object. This avoids any direct dependency on the HCI layer and lets the l2cap core handle any specifics. This patch introduces l2cap_user objects which contain a "probe" and "remove" callback. You can register them on any l2cap_conn object and if it is active, the "probe" callback will get called. Otherwise, an error is returned. The l2cap_conn object will call your "remove" callback directly before it is removed from user-space. This allows you to remove your submodules _before_ the parent l2cap_conn and hci_conn object is removed. At any time you can asynchronously unregister your l2cap_user object if your submodule vanishes before the l2cap_conn object does. There is no way around l2cap_user. If we want wire-protocols in the kernel, we always want the hci_conn object as parent in the sysfs tree. We cannot use a channel here since we might need multiple channels for a single protocol. But the problem is, we _must_ get notified when an l2cap_conn object is removed. We cannot use reference-counting for object-removal! This is not how it works. If a hardware is removed, we should immediately remove the object from sysfs. Any other behavior would be inconsistent with the rest of the system. Also note that device_del() might sleep, but it doesn't wait for user-space or block very long. It only _unlinks_ the object from sysfs and the whole device-tree. Everything else is handled by ref-counts! This is exactly what the other sub-modules must do: unlink their devices when the "remove" l2cap_user callback is called. They should not do any cleanup or synchronous shutdowns. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
2013-04-06 20:28:45 +02:00