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2f304d1e8b
We don't need to use the _sync variant in hci_conn_hold and hci_conn_put to cancel conn->disc_work delayed work. This way we avoid potential deadlocks like this one reported by lockdep. ====================================================== [ INFO: possible circular locking dependency detected ] 3.2.0+ #1 Not tainted ------------------------------------------------------- kworker/u:1/17 is trying to acquire lock: (&hdev->lock){+.+.+.}, at: [<ffffffffa0041155>] hci_conn_timeout+0x62/0x158 [bluetooth] but task is already holding lock: ((&(&conn->disc_work)->work)){+.+...}, at: [<ffffffff81035751>] process_one_work+0x11a/0x2bf which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((&(&conn->disc_work)->work)){+.+...}: [<ffffffff81057444>] lock_acquire+0x8a/0xa7 [<ffffffff81034ed1>] wait_on_work+0x3d/0xaa [<ffffffff81035b54>] __cancel_work_timer+0xac/0xef [<ffffffff81035ba4>] cancel_delayed_work_sync+0xd/0xf [<ffffffffa00554b0>] smp_chan_create+0xde/0xe6 [bluetooth] [<ffffffffa0056160>] smp_conn_security+0xa3/0x12d [bluetooth] [<ffffffffa0053640>] l2cap_connect_cfm+0x237/0x2e8 [bluetooth] [<ffffffffa004239c>] hci_proto_connect_cfm+0x2d/0x6f [bluetooth] [<ffffffffa0046ea5>] hci_event_packet+0x29d1/0x2d60 [bluetooth] [<ffffffffa003dde3>] hci_rx_work+0xd0/0x2e1 [bluetooth] [<ffffffff810357af>] process_one_work+0x178/0x2bf [<ffffffff81036178>] worker_thread+0xce/0x152 [<ffffffff81039a03>] kthread+0x95/0x9d [<ffffffff812e7754>] kernel_thread_helper+0x4/0x10 -> #1 (slock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}: [<ffffffff81057444>] lock_acquire+0x8a/0xa7 [<ffffffff812e553a>] _raw_spin_lock_bh+0x36/0x6a [<ffffffff81244d56>] lock_sock_nested+0x24/0x7f [<ffffffffa004d96f>] lock_sock+0xb/0xd [bluetooth] [<ffffffffa0052906>] l2cap_chan_connect+0xa9/0x26f [bluetooth] [<ffffffffa00545f8>] l2cap_sock_connect+0xb3/0xff [bluetooth] [<ffffffff81243b48>] sys_connect+0x69/0x8a [<ffffffff812e6579>] system_call_fastpath+0x16/0x1b -> #0 (&hdev->lock){+.+.+.}: [<ffffffff81056d06>] __lock_acquire+0xa80/0xd74 [<ffffffff81057444>] lock_acquire+0x8a/0xa7 [<ffffffff812e3870>] __mutex_lock_common+0x48/0x38e [<ffffffff812e3c75>] mutex_lock_nested+0x2a/0x31 [<ffffffffa0041155>] hci_conn_timeout+0x62/0x158 [bluetooth] [<ffffffff810357af>] process_one_work+0x178/0x2bf [<ffffffff81036178>] worker_thread+0xce/0x152 [<ffffffff81039a03>] kthread+0x95/0x9d [<ffffffff812e7754>] kernel_thread_helper+0x4/0x10 other info that might help us debug this: Chain exists of: &hdev->lock --> slock-AF_BLUETOOTH-BTPROTO_L2CAP --> (&(&conn->disc_work)->work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((&(&conn->disc_work)->work)); lock(slock-AF_BLUETOOTH-BTPROTO_L2CAP); lock((&(&conn->disc_work)->work)); lock(&hdev->lock); *** DEADLOCK *** 2 locks held by kworker/u:1/17: #0: (hdev->name){.+.+.+}, at: [<ffffffff81035751>] process_one_work+0x11a/0x2bf #1: ((&(&conn->disc_work)->work)){+.+...}, at: [<ffffffff81035751>] process_one_work+0x11a/0x2bf stack backtrace: Pid: 17, comm: kworker/u:1 Not tainted 3.2.0+ #1 Call Trace: [<ffffffff812e06c6>] print_circular_bug+0x1f8/0x209 [<ffffffff81056d06>] __lock_acquire+0xa80/0xd74 [<ffffffff81021ef2>] ? arch_local_irq_restore+0x6/0xd [<ffffffff81022bc7>] ? vprintk+0x3f9/0x41e [<ffffffff81057444>] lock_acquire+0x8a/0xa7 [<ffffffffa0041155>] ? hci_conn_timeout+0x62/0x158 [bluetooth] [<ffffffff812e3870>] __mutex_lock_common+0x48/0x38e [<ffffffffa0041155>] ? hci_conn_timeout+0x62/0x158 [bluetooth] [<ffffffff81190fd6>] ? __dynamic_pr_debug+0x6d/0x6f [<ffffffffa0041155>] ? hci_conn_timeout+0x62/0x158 [bluetooth] [<ffffffff8105320f>] ? trace_hardirqs_off+0xd/0xf [<ffffffff812e3c75>] mutex_lock_nested+0x2a/0x31 [<ffffffffa0041155>] hci_conn_timeout+0x62/0x158 [bluetooth] [<ffffffff810357af>] process_one_work+0x178/0x2bf [<ffffffff81035751>] ? process_one_work+0x11a/0x2bf [<ffffffff81055af3>] ? lock_acquired+0x1d0/0x1df [<ffffffffa00410f3>] ? hci_acl_disconn+0x65/0x65 [bluetooth] [<ffffffff81036178>] worker_thread+0xce/0x152 [<ffffffff810407ed>] ? finish_task_switch+0x45/0xc5 [<ffffffff810360aa>] ? manage_workers.isra.25+0x16a/0x16a [<ffffffff81039a03>] kthread+0x95/0x9d [<ffffffff812e7754>] kernel_thread_helper+0x4/0x10 [<ffffffff812e5db4>] ? retint_restore_args+0x13/0x13 [<ffffffff8103996e>] ? __init_kthread_worker+0x55/0x55 [<ffffffff812e7750>] ? gs_change+0x13/0x13 Signed-off-by: Andre Guedes <andre.guedes@openbossa.org> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org> Reviewed-by: Ulisses Furquim <ulisses@profusion.mobi> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com> |
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| .. | ||
| 9p | ||
| bluetooth | ||
| caif | ||
| irda | ||
| iucv | ||
| netfilter | ||
| netns | ||
| nfc | ||
| phonet | ||
| sctp | ||
| tc_act | ||
| act_api.h | ||
| addrconf.h | ||
| af_ieee802154.h | ||
| af_rxrpc.h | ||
| af_unix.h | ||
| ah.h | ||
| arp.h | ||
| atmclip.h | ||
| ax25.h | ||
| ax88796.h | ||
| cfg80211-wext.h | ||
| cfg80211.h | ||
| checksum.h | ||
| cipso_ipv4.h | ||
| cls_cgroup.h | ||
| compat.h | ||
| datalink.h | ||
| dcbevent.h | ||
| dcbnl.h | ||
| dn_dev.h | ||
| dn_fib.h | ||
| dn_neigh.h | ||
| dn_nsp.h | ||
| dn_route.h | ||
| dn.h | ||
| dsa.h | ||
| dsfield.h | ||
| dst_ops.h | ||
| dst.h | ||
| esp.h | ||
| ethoc.h | ||
| fib_rules.h | ||
| flow_keys.h | ||
| flow.h | ||
| garp.h | ||
| gen_stats.h | ||
| genetlink.h | ||
| gre.h | ||
| icmp.h | ||
| ieee80211_radiotap.h | ||
| ieee802154_netdev.h | ||
| ieee802154.h | ||
| if_inet6.h | ||
| inet6_connection_sock.h | ||
| inet6_hashtables.h | ||
| inet_common.h | ||
| inet_connection_sock.h | ||
| inet_ecn.h | ||
| inet_frag.h | ||
| inet_hashtables.h | ||
| inet_sock.h | ||
| inet_timewait_sock.h | ||
| inetpeer.h | ||
| ip6_checksum.h | ||
| ip6_fib.h | ||
| ip6_route.h | ||
| ip6_tunnel.h | ||
| ip_fib.h | ||
| ip_vs.h | ||
| ip.h | ||
| ipcomp.h | ||
| ipconfig.h | ||
| ipip.h | ||
| ipv6.h | ||
| ipx.h | ||
| iw_handler.h | ||
| lapb.h | ||
| lib80211.h | ||
| llc_c_ac.h | ||
| llc_c_ev.h | ||
| llc_c_st.h | ||
| llc_conn.h | ||
| llc_if.h | ||
| llc_pdu.h | ||
| llc_s_ac.h | ||
| llc_s_ev.h | ||
| llc_s_st.h | ||
| llc_sap.h | ||
| llc.h | ||
| mac80211.h | ||
| mip6.h | ||
| mld.h | ||
| ndisc.h | ||
| neighbour.h | ||
| net_namespace.h | ||
| net_ratelimit.h | ||
| netdma.h | ||
| netevent.h | ||
| netlabel.h | ||
| netlink.h | ||
| netprio_cgroup.h | ||
| netrom.h | ||
| nexthop.h | ||
| nl802154.h | ||
| p8022.h | ||
| ping.h | ||
| pkt_cls.h | ||
| pkt_sched.h | ||
| protocol.h | ||
| psnap.h | ||
| raw.h | ||
| rawv6.h | ||
| red.h | ||
| regulatory.h | ||
| request_sock.h | ||
| rose.h | ||
| route.h | ||
| rtnetlink.h | ||
| sch_generic.h | ||
| scm.h | ||
| secure_seq.h | ||
| slhc_vj.h | ||
| snmp.h | ||
| sock.h | ||
| stp.h | ||
| tcp_memcontrol.h | ||
| tcp_states.h | ||
| tcp.h | ||
| timewait_sock.h | ||
| transp_v6.h | ||
| udp.h | ||
| udplite.h | ||
| wext.h | ||
| wimax.h | ||
| wpan-phy.h | ||
| x25.h | ||
| x25device.h | ||
| xfrm.h | ||