[PATCH] bluetooth: fix socket locking in hci_sock_dev_event()
[Bluetooth] Fix socket locking in hci_sock_dev_event() hci_sock_dev_event() uses bh_lock_sock() to lock the socket lock. This is not deadlock-safe against locking of the same socket lock in l2cap_connect_cfm() from softirq context. In addition to that, hci_sock_dev_event() doesn't seem to be called from softirq context, so it is safe to use lock_sock()/release_sock() instead. The lockdep warning can be triggered on my T42p simply by switching the Bluetooth off by the keyboard button. ================================= [ INFO: inconsistent lock state ] 2.6.21-rc2 #4 --------------------------------- inconsistent {in-softirq-W} -> {softirq-on-W} usage. khubd/156 [HC0[0]:SC0[0]:HE1:SE1] takes: (slock-AF_BLUETOOTH){-+..}, at: [<e0ca5520>] hci_sock_dev_event+0xa8/0xc5 [bluetooth] {in-softirq-W} state was registered at: [<c012d1db>] mark_lock+0x59/0x414 [<e0cef688>] l2cap_connect_cfm+0x4e/0x11f [l2cap] [<c012dfd7>] __lock_acquire+0x3e5/0xb99 [<e0cef688>] l2cap_connect_cfm+0x4e/0x11f [l2cap] [<c012e7f2>] lock_acquire+0x67/0x81 [<e0cef688>] l2cap_connect_cfm+0x4e/0x11f [l2cap] [<c036ee72>] _spin_lock+0x29/0x34 [<e0cef688>] l2cap_connect_cfm+0x4e/0x11f [l2cap] [<e0cef688>] l2cap_connect_cfm+0x4e/0x11f [l2cap] [<e0ca17c3>] hci_send_cmd+0x126/0x14f [bluetooth] [<e0ca4ce4>] hci_event_packet+0x729/0xebd [bluetooth] [<e0ca205b>] hci_rx_task+0x2a/0x20f [bluetooth] [<e0ca209d>] hci_rx_task+0x6c/0x20f [bluetooth] [<c012d7be>] trace_hardirqs_on+0x10d/0x14e [<c011ac85>] tasklet_action+0x3d/0x68 [<c011abba>] __do_softirq+0x41/0x92 [<c011ac32>] do_softirq+0x27/0x3d [<c0105134>] do_IRQ+0x7b/0x8f [<c0103dec>] common_interrupt+0x24/0x34 [<c0103df6>] common_interrupt+0x2e/0x34 [<c0248e65>] acpi_processor_idle+0x1b3/0x34a [<c0248e68>] acpi_processor_idle+0x1b6/0x34a [<c010232b>] cpu_idle+0x39/0x4e [<c04bab0c>] start_kernel+0x372/0x37a [<c04ba42b>] unknown_bootoption+0x0/0x202 [<ffffffff>] 0xffffffff Signed-off-by:Jiri Kosina <jkosina@suse.cz> Acked-by:
Marcel Holtmann <marcel@holtmann.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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47c51dff