[mmotm 2009-10-09-01-07] b43/wireless possible circular locking
From: Dave Young
Date: Sun Oct 11 2009 - 05:43:46 EST
Hi,
I got lockdep warnings about possible circular lock with
b43 interface startup. It looks like a real problem.
[ 71.974542] wlan0: deauthenticating from 00:19:e0:db:24:de by local choice (reason=3)
[ 72.004352] b43-phy0 debug: Removing Interface type 2
[ 72.005431]
[ 72.005435] =======================================================
[ 72.006168] [ INFO: possible circular locking dependency detected ]
[ 72.006759] 2.6.32-rc3-mm1 #4
[ 72.007047] -------------------------------------------------------
[ 72.007617] ifconfig/2175 is trying to acquire lock:
[ 72.007617] (&(&rfkill->poll_work)->work){+.+...}, at: [<c0239375>] __cancel_work_timer+0x8c/0x18e
[ 72.007617]
[ 72.007617] but task is already holding lock:
[ 72.007617] (&wl->mutex){+.+.+.}, at: [<f8fa5359>] b43_op_stop+0x28/0x6a [b43]
[ 72.007617]
[ 72.007617] which lock already depends on the new lock.
[ 72.007617]
[ 72.007617]
[ 72.007617] the existing dependency chain (in reverse order) is:
[ 72.007617]
[ 72.007617] -> #1 (&wl->mutex){+.+.+.}:
[ 72.007617] [<c024b251>] __lock_acquire+0x9e2/0xb73
[ 72.007617] [<c024b449>] lock_acquire+0x67/0x84
[ 72.007617] [<c055854d>] __mutex_lock_common+0x35/0x2ca
[ 72.007617] [<c0558880>] mutex_lock_nested+0x30/0x38
[ 72.007617] [<f8fb9bcd>] b43_rfkill_poll+0x26/0xc9 [b43]
[ 72.007617] [<f8f8330e>] ieee80211_rfkill_poll+0x1f/0x21 [mac80211]
[ 72.007617] [<f8396011>] cfg80211_rfkill_poll+0x11/0x13 [cfg80211]
[ 72.007617] [<f826b740>] rfkill_poll+0x14/0x2a [rfkill]
[ 72.007617] [<c0239927>] worker_thread+0x13b/0x1ff
[ 72.007617] [<c023be0c>] kthread+0x58/0x5d
[ 72.007617] [<c0203d07>] kernel_thread_helper+0x7/0x10
[ 72.007617]
[ 72.007617] -> #0 (&(&rfkill->poll_work)->work){+.+...}:
[ 72.007617] [<c024b15c>] __lock_acquire+0x8ed/0xb73
[ 72.007617] [<c024b449>] lock_acquire+0x67/0x84
[ 72.007617] [<c02393a2>] __cancel_work_timer+0xb9/0x18e
[ 72.007617] [<c0239482>] cancel_delayed_work_sync+0xb/0xd
[ 72.007617] [<f826b71b>] rfkill_pause_polling+0x20/0x22 [rfkill]
[ 72.007617] [<f8396328>] wiphy_rfkill_stop_polling+0x10/0x12 [cfg80211]
[ 72.007617] [<f8fa5361>] b43_op_stop+0x30/0x6a [b43]
[ 72.007617] [<f8f895af>] ieee80211_stop_device+0x20/0x53 [mac80211]
[ 72.007617] [<f8f8141d>] ieee80211_stop+0x3d3/0x452 [mac80211]
[ 72.007617] [<c04e0c47>] dev_close+0x74/0x90
[ 72.007617] [<c04e082c>] dev_change_flags+0x96/0x144
[ 72.007617] [<c05262fd>] devinet_ioctl+0x212/0x468
[ 72.007617] [<c052814d>] inet_ioctl+0x8e/0xa7
[ 72.007617] [<c04d3e16>] sock_ioctl+0x1d3/0x1f7
[ 72.007617] [<c02a6b49>] vfs_ioctl+0x22/0x67
[ 72.007617] [<c02a707d>] do_vfs_ioctl+0x45f/0x493
[ 72.007617] [<c02a70f1>] sys_ioctl+0x40/0x5a
[ 72.007617] [<c020325d>] syscall_call+0x7/0xb
[ 72.007617]
[ 72.007617] other info that might help us debug this:
[ 72.007617]
[ 72.007617] 2 locks held by ifconfig/2175:
[ 72.007617] #0: (rtnl_mutex){+.+.+.}, at: [<c04e8b90>] rtnl_lock+0xf/0x11
[ 72.007617] #1: (&wl->mutex){+.+.+.}, at: [<f8fa5359>] b43_op_stop+0x28/0x6a [b43]
[ 72.007617]
[ 72.007617] stack backtrace:
[ 72.007617] Pid: 2175, comm: ifconfig Not tainted 2.6.32-rc3-mm1 #4
[ 72.007617] Call Trace:
[ 72.007617] [<c024a863>] print_circular_bug+0x8a/0x96
[ 72.007617] [<c024b15c>] __lock_acquire+0x8ed/0xb73
[ 72.007617] [<c024b449>] lock_acquire+0x67/0x84
[ 72.007617] [<c0239375>] ? __cancel_work_timer+0x8c/0x18e
[ 72.007617] [<c02393a2>] __cancel_work_timer+0xb9/0x18e
[ 72.007617] [<c0239375>] ? __cancel_work_timer+0x8c/0x18e
[ 72.007617] [<c05587c8>] ? __mutex_lock_common+0x2b0/0x2ca
[ 72.007617] [<c0248233>] ? debug_mutex_free_waiter+0x45/0x48
[ 72.007617] [<c05587d8>] ? __mutex_lock_common+0x2c0/0x2ca
[ 72.007617] [<c0239482>] cancel_delayed_work_sync+0xb/0xd
[ 72.007617] [<f826b71b>] rfkill_pause_polling+0x20/0x22 [rfkill]
[ 72.007617] [<f8396328>] wiphy_rfkill_stop_polling+0x10/0x12 [cfg80211]
[ 72.007617] [<f8fa5361>] b43_op_stop+0x30/0x6a [b43]
[ 72.007617] [<f8f895af>] ieee80211_stop_device+0x20/0x53 [mac80211]
[ 72.007617] [<f8f8141d>] ieee80211_stop+0x3d3/0x452 [mac80211]
[ 72.007617] [<c0249d42>] ? trace_hardirqs_on+0xb/0xd
[ 72.007617] [<c022fd77>] ? _local_bh_enable_ip+0x9d/0xa6
[ 72.007617] [<c022fd88>] ? local_bh_enable_ip+0x8/0xa
[ 72.007617] [<c05592a8>] ? _spin_unlock_bh+0x25/0x28
[ 72.007617] [<c04e0c47>] dev_close+0x74/0x90
[ 72.007617] [<c04e082c>] dev_change_flags+0x96/0x144
[ 72.007617] [<c05262fd>] devinet_ioctl+0x212/0x468
[ 72.007617] [<c052814d>] inet_ioctl+0x8e/0xa7
[ 72.007617] [<c04d3e16>] sock_ioctl+0x1d3/0x1f7
[ 72.007617] [<c04d3c43>] ? sock_ioctl+0x0/0x1f7
[ 72.007617] [<c02a6b49>] vfs_ioctl+0x22/0x67
[ 72.007617] [<c02a707d>] do_vfs_ioctl+0x45f/0x493
[ 72.007617] [<c0221652>] ? need_resched+0x14/0x1e
[ 72.007617] [<c0557e29>] ? schedule+0x6ed/0x6fd
[ 72.007617] [<c055b24e>] ? do_page_fault+0x29d/0x2a5
[ 72.007617] [<c02a70f1>] sys_ioctl+0x40/0x5a
[ 72.007617] [<c020325d>] syscall_call+0x7/0xb
[ 73.122930] b43-phy0 debug: Wireless interface stopped
[ 73.131557] ifconfig used greatest stack depth: 5660 bytes left
[ 73.310494] b43-phy0: Loading firmware version 410.2160 (2007-05-26 15:32:10)
[ 73.329042] b43-phy0 debug: b2062: Using crystal tab entry 19200 kHz.
[ 77.923855] b43-phy0 debug: Chip initialized
[ 77.924695] b43-phy0 debug: PIO initialized
[ 77.925410] b43-phy0 debug: QoS enabled
[ 77.941415] b43-phy0 debug: Wireless interface started
[ 77.942164] b43-phy0 debug: Adding Interface type 2
[ 77.961969] wlan0: direct probe to AP 00:19:e0:db:24:de (try 1)
[ 78.160198] wlan0: direct probe to AP 00:19:e0:db:24:de (try 2)
[ 78.164241] wlan0: direct probe responded
[ 78.164649] wlan0: authenticate with AP 00:19:e0:db:24:de (try 1)
[ 78.167341] wlan0: authenticated
[ 78.167791] wlan0: associate with AP 00:19:e0:db:24:de (try 1)
[ 78.170935] wlan0: RX ReassocResp from 00:19:e0:db:24:de (capab=0x421 status=0 aid=4)
[ 78.171690] wlan0: associated
--
Regards
dave
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