* [2.6.38-rc5, patch] fix cfg80211_wext_siwfreq lock ordering...
@ 2011-02-21 16:11 Daniel J Blueman
2011-02-21 16:25 ` Johannes Berg
0 siblings, 1 reply; 6+ messages in thread
From: Daniel J Blueman @ 2011-02-21 16:11 UTC (permalink / raw)
To: Johannes Berg, linux-wireless; +Cc: Linux Kernel
I previously managed to reproduce a hang while scanning wireless
channels (reproducible with airodump-ng hopping channels); subsequent
lockdep instrumentation revealed a lock ordering issue [1].
Without knowing the design intent, it looks like the locks should be
taken in reverse order; please comment.
Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
--- [1]
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.38-rc5-341cd #4
-------------------------------------------------------
airodump-ng/15445 is trying to acquire lock:
(&rdev->devlist_mtx){+.+.+.}, at: [<ffffffff816b1266>]
cfg80211_wext_siwfreq+0xc6/0x100
but task is already holding lock:
(&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] cfg80211_wext_siwfreq+0xbc/0x100
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&wdev->mtx){+.+.+.}:
[<ffffffff810a79d6>] lock_acquire+0xc6/0x280
[<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0
[<ffffffff81696080>] cfg80211_netdev_notifier_call+0x430/0x5f0
[<ffffffff8109351b>] notifier_call_chain+0x8b/0x100
[<ffffffff810935b1>] raw_notifier_call_chain+0x11/0x20
[<ffffffff81576d92>] call_netdevice_notifiers+0x32/0x60
[<ffffffff815771a4>] __dev_notify_flags+0x34/0x80
[<ffffffff81577230>] dev_change_flags+0x40/0x70
[<ffffffff8158587c>] do_setlink+0x1fc/0x8d0
[<ffffffff81586042>] rtnl_setlink+0xf2/0x140
[<ffffffff81586923>] rtnetlink_rcv_msg+0x163/0x270
[<ffffffff8159d741>] netlink_rcv_skb+0xa1/0xd0
[<ffffffff815867b0>] rtnetlink_rcv+0x20/0x30
[<ffffffff8159d39a>] netlink_unicast+0x2ba/0x300
[<ffffffff8159dd57>] netlink_sendmsg+0x267/0x3e0
[<ffffffff8155e364>] sock_sendmsg+0xe4/0x110
[<ffffffff8155f3a3>] sys_sendmsg+0x253/0x3b0
[<ffffffff81003192>] system_call_fastpath+0x16/0x1b
-> #0 (&rdev->devlist_mtx){+.+.+.}:
[<ffffffff810a7222>] __lock_acquire+0x1622/0x1d10
[<ffffffff810a79d6>] lock_acquire+0xc6/0x280
[<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0
[<ffffffff816b1266>] cfg80211_wext_siwfreq+0xc6/0x100
[<ffffffff816b2fad>] ioctl_standard_call+0x5d/0xd0
[<ffffffff816b3223>] T.808+0x163/0x170
[<ffffffff816b326a>] wext_handle_ioctl+0x3a/0x90
[<ffffffff815798d2>] dev_ioctl+0x6f2/0x830
[<ffffffff8155cf3d>] sock_ioctl+0xfd/0x290
[<ffffffff8117dffd>] do_vfs_ioctl+0x9d/0x590
[<ffffffff8117e53a>] sys_ioctl+0x4a/0x80
[<ffffffff81003192>] system_call_fastpath+0x16/0x1b
other info that might help us debug this:
2 locks held by airodump-ng/15445:
#0: (rtnl_mutex){+.+.+.}, at: [<ffffffff81586782>] rtnl_lock+0x12/0x20
#1: (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>]
cfg80211_wext_siwfreq+0xbc/0x100
stack backtrace:
Pid: 15445, comm: airodump-ng Not tainted 2.6.38-rc5-341cd #4
Call Trace:
[<ffffffff810a3f0a>] ? print_circular_bug+0xfa/0x100
[<ffffffff810a7222>] ? __lock_acquire+0x1622/0x1d10
[<ffffffff810a1f99>] ? trace_hardirqs_off_caller+0x29/0xc0
[<ffffffff810a79d6>] ? lock_acquire+0xc6/0x280
[<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100
[<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90
[<ffffffff816d6bce>] ? mutex_lock_nested+0x6e/0x4b0
[<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100
[<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90
[<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100
[<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100
[<ffffffff816b2fad>] ? ioctl_standard_call+0x5d/0xd0
[<ffffffff8157818b>] ? __dev_get_by_name+0x9b/0xc0
[<ffffffff816b2f50>] ? ioctl_standard_call+0x0/0xd0
[<ffffffff816b3223>] ? T.808+0x163/0x170
[<ffffffff8112ddf2>] ? might_fault+0x72/0xd0
[<ffffffff816b326a>] ? wext_handle_ioctl+0x3a/0x90
[<ffffffff8112de3b>] ? might_fault+0xbb/0xd0
[<ffffffff815798d2>] ? dev_ioctl+0x6f2/0x830
[<ffffffff810a1bae>] ? put_lock_stats+0xe/0x40
[<ffffffff810a1c8c>] ? lock_release_holdtime+0xac/0x150
[<ffffffff8155cf3d>] ? sock_ioctl+0xfd/0x290
[<ffffffff8117dffd>] ? do_vfs_ioctl+0x9d/0x590
[<ffffffff8116c8ff>] ? fget_light+0x1df/0x3c0
[<ffffffff8117e53a>] ? sys_ioctl+0x4a/0x80
[<ffffffff81003192>] ? system_call_fastpath+0x16/0x1b
--- [2]
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index 3e5dbd4..d112f03 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -802,11 +802,11 @@ int cfg80211_wext_siwfreq(struct net_device *dev,
return freq;
if (freq == 0)
return -EINVAL;
- wdev_lock(wdev);
mutex_lock(&rdev->devlist_mtx);
+ wdev_lock(wdev);
err = cfg80211_set_freq(rdev, wdev, freq, NL80211_CHAN_NO_HT);
- mutex_unlock(&rdev->devlist_mtx);
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);
return err;
default:
return -EOPNOTSUPP;
--
Daniel J Blueman
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [2.6.38-rc5, patch] fix cfg80211_wext_siwfreq lock ordering... 2011-02-21 16:11 [2.6.38-rc5, patch] fix cfg80211_wext_siwfreq lock ordering Daniel J Blueman @ 2011-02-21 16:25 ` Johannes Berg 2011-02-22 1:15 ` Daniel J Blueman 0 siblings, 1 reply; 6+ messages in thread From: Johannes Berg @ 2011-02-21 16:25 UTC (permalink / raw) To: Daniel J Blueman; +Cc: linux-wireless, Linux Kernel On Tue, 2011-02-22 at 00:11 +0800, Daniel J Blueman wrote: > I previously managed to reproduce a hang while scanning wireless > channels (reproducible with airodump-ng hopping channels); subsequent > lockdep instrumentation revealed a lock ordering issue [1]. > > Without knowing the design intent, it looks like the locks should be > taken in reverse order; please comment. > > Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> > > --- [1] Yeah, looks this way, thanks. Acked-by: Johannes Berg <johannes@sipsolutions.net> > ======================================================= > [ INFO: possible circular locking dependency detected ] > 2.6.38-rc5-341cd #4 > ------------------------------------------------------- > airodump-ng/15445 is trying to acquire lock: > (&rdev->devlist_mtx){+.+.+.}, at: [<ffffffff816b1266>] > cfg80211_wext_siwfreq+0xc6/0x100 > > but task is already holding lock: > (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] cfg80211_wext_siwfreq+0xbc/0x100 > > which lock already depends on the new lock. > > the existing dependency chain (in reverse order) is: > > -> #1 (&wdev->mtx){+.+.+.}: > [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 > [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 > [<ffffffff81696080>] cfg80211_netdev_notifier_call+0x430/0x5f0 > [<ffffffff8109351b>] notifier_call_chain+0x8b/0x100 > [<ffffffff810935b1>] raw_notifier_call_chain+0x11/0x20 > [<ffffffff81576d92>] call_netdevice_notifiers+0x32/0x60 > [<ffffffff815771a4>] __dev_notify_flags+0x34/0x80 > [<ffffffff81577230>] dev_change_flags+0x40/0x70 > [<ffffffff8158587c>] do_setlink+0x1fc/0x8d0 > [<ffffffff81586042>] rtnl_setlink+0xf2/0x140 > [<ffffffff81586923>] rtnetlink_rcv_msg+0x163/0x270 > [<ffffffff8159d741>] netlink_rcv_skb+0xa1/0xd0 > [<ffffffff815867b0>] rtnetlink_rcv+0x20/0x30 > [<ffffffff8159d39a>] netlink_unicast+0x2ba/0x300 > [<ffffffff8159dd57>] netlink_sendmsg+0x267/0x3e0 > [<ffffffff8155e364>] sock_sendmsg+0xe4/0x110 > [<ffffffff8155f3a3>] sys_sendmsg+0x253/0x3b0 > [<ffffffff81003192>] system_call_fastpath+0x16/0x1b > > -> #0 (&rdev->devlist_mtx){+.+.+.}: > [<ffffffff810a7222>] __lock_acquire+0x1622/0x1d10 > [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 > [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 > [<ffffffff816b1266>] cfg80211_wext_siwfreq+0xc6/0x100 > [<ffffffff816b2fad>] ioctl_standard_call+0x5d/0xd0 > [<ffffffff816b3223>] T.808+0x163/0x170 > [<ffffffff816b326a>] wext_handle_ioctl+0x3a/0x90 > [<ffffffff815798d2>] dev_ioctl+0x6f2/0x830 > [<ffffffff8155cf3d>] sock_ioctl+0xfd/0x290 > [<ffffffff8117dffd>] do_vfs_ioctl+0x9d/0x590 > [<ffffffff8117e53a>] sys_ioctl+0x4a/0x80 > [<ffffffff81003192>] system_call_fastpath+0x16/0x1b > > other info that might help us debug this: > > 2 locks held by airodump-ng/15445: > #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff81586782>] rtnl_lock+0x12/0x20 > #1: (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] > cfg80211_wext_siwfreq+0xbc/0x100 > > stack backtrace: > Pid: 15445, comm: airodump-ng Not tainted 2.6.38-rc5-341cd #4 > Call Trace: > [<ffffffff810a3f0a>] ? print_circular_bug+0xfa/0x100 > [<ffffffff810a7222>] ? __lock_acquire+0x1622/0x1d10 > [<ffffffff810a1f99>] ? trace_hardirqs_off_caller+0x29/0xc0 > [<ffffffff810a79d6>] ? lock_acquire+0xc6/0x280 > [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 > [<ffffffff816d6bce>] ? mutex_lock_nested+0x6e/0x4b0 > [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 > [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > [<ffffffff816b2fad>] ? ioctl_standard_call+0x5d/0xd0 > [<ffffffff8157818b>] ? __dev_get_by_name+0x9b/0xc0 > [<ffffffff816b2f50>] ? ioctl_standard_call+0x0/0xd0 > [<ffffffff816b3223>] ? T.808+0x163/0x170 > [<ffffffff8112ddf2>] ? might_fault+0x72/0xd0 > [<ffffffff816b326a>] ? wext_handle_ioctl+0x3a/0x90 > [<ffffffff8112de3b>] ? might_fault+0xbb/0xd0 > [<ffffffff815798d2>] ? dev_ioctl+0x6f2/0x830 > [<ffffffff810a1bae>] ? put_lock_stats+0xe/0x40 > [<ffffffff810a1c8c>] ? lock_release_holdtime+0xac/0x150 > [<ffffffff8155cf3d>] ? sock_ioctl+0xfd/0x290 > [<ffffffff8117dffd>] ? do_vfs_ioctl+0x9d/0x590 > [<ffffffff8116c8ff>] ? fget_light+0x1df/0x3c0 > [<ffffffff8117e53a>] ? sys_ioctl+0x4a/0x80 > [<ffffffff81003192>] ? system_call_fastpath+0x16/0x1b > > --- [2] > > diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c > index 3e5dbd4..d112f03 100644 > --- a/net/wireless/wext-compat.c > +++ b/net/wireless/wext-compat.c > @@ -802,11 +802,11 @@ int cfg80211_wext_siwfreq(struct net_device *dev, > return freq; > if (freq == 0) > return -EINVAL; > - wdev_lock(wdev); > mutex_lock(&rdev->devlist_mtx); > + wdev_lock(wdev); > err = cfg80211_set_freq(rdev, wdev, freq, NL80211_CHAN_NO_HT); > - mutex_unlock(&rdev->devlist_mtx); > wdev_unlock(wdev); > + mutex_unlock(&rdev->devlist_mtx); > return err; > default: > return -EOPNOTSUPP; ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [2.6.38-rc5, patch] fix cfg80211_wext_siwfreq lock ordering... 2011-02-21 16:25 ` Johannes Berg @ 2011-02-22 1:15 ` Daniel J Blueman 2011-02-22 20:02 ` [stable] " Greg KH 0 siblings, 1 reply; 6+ messages in thread From: Daniel J Blueman @ 2011-02-22 1:15 UTC (permalink / raw) To: stable; +Cc: linux-wireless, Linux Kernel, Johannes Berg On 22 February 2011 00:25, Johannes Berg <johannes@sipsolutions.net> wrote: > On Tue, 2011-02-22 at 00:11 +0800, Daniel J Blueman wrote: >> I previously managed to reproduce a hang while scanning wireless >> channels (reproducible with airodump-ng hopping channels); subsequent >> lockdep instrumentation revealed a lock ordering issue [1]. >> >> Without knowing the design intent, it looks like the locks should be >> taken in reverse order; please comment. >> >> Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> >> >> --- [1] > > Yeah, looks this way, thanks. > > Acked-by: Johannes Berg <johannes@sipsolutions.net> > >> ======================================================= >> [ INFO: possible circular locking dependency detected ] >> 2.6.38-rc5-341cd #4 >> ------------------------------------------------------- >> airodump-ng/15445 is trying to acquire lock: >> (&rdev->devlist_mtx){+.+.+.}, at: [<ffffffff816b1266>] >> cfg80211_wext_siwfreq+0xc6/0x100 >> >> but task is already holding lock: >> (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] cfg80211_wext_siwfreq+0xbc/0x100 >> >> which lock already depends on the new lock. >> >> the existing dependency chain (in reverse order) is: >> >> -> #1 (&wdev->mtx){+.+.+.}: >> [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 >> [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 >> [<ffffffff81696080>] cfg80211_netdev_notifier_call+0x430/0x5f0 >> [<ffffffff8109351b>] notifier_call_chain+0x8b/0x100 >> [<ffffffff810935b1>] raw_notifier_call_chain+0x11/0x20 >> [<ffffffff81576d92>] call_netdevice_notifiers+0x32/0x60 >> [<ffffffff815771a4>] __dev_notify_flags+0x34/0x80 >> [<ffffffff81577230>] dev_change_flags+0x40/0x70 >> [<ffffffff8158587c>] do_setlink+0x1fc/0x8d0 >> [<ffffffff81586042>] rtnl_setlink+0xf2/0x140 >> [<ffffffff81586923>] rtnetlink_rcv_msg+0x163/0x270 >> [<ffffffff8159d741>] netlink_rcv_skb+0xa1/0xd0 >> [<ffffffff815867b0>] rtnetlink_rcv+0x20/0x30 >> [<ffffffff8159d39a>] netlink_unicast+0x2ba/0x300 >> [<ffffffff8159dd57>] netlink_sendmsg+0x267/0x3e0 >> [<ffffffff8155e364>] sock_sendmsg+0xe4/0x110 >> [<ffffffff8155f3a3>] sys_sendmsg+0x253/0x3b0 >> [<ffffffff81003192>] system_call_fastpath+0x16/0x1b >> >> -> #0 (&rdev->devlist_mtx){+.+.+.}: >> [<ffffffff810a7222>] __lock_acquire+0x1622/0x1d10 >> [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 >> [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 >> [<ffffffff816b1266>] cfg80211_wext_siwfreq+0xc6/0x100 >> [<ffffffff816b2fad>] ioctl_standard_call+0x5d/0xd0 >> [<ffffffff816b3223>] T.808+0x163/0x170 >> [<ffffffff816b326a>] wext_handle_ioctl+0x3a/0x90 >> [<ffffffff815798d2>] dev_ioctl+0x6f2/0x830 >> [<ffffffff8155cf3d>] sock_ioctl+0xfd/0x290 >> [<ffffffff8117dffd>] do_vfs_ioctl+0x9d/0x590 >> [<ffffffff8117e53a>] sys_ioctl+0x4a/0x80 >> [<ffffffff81003192>] system_call_fastpath+0x16/0x1b >> >> other info that might help us debug this: >> >> 2 locks held by airodump-ng/15445: >> #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff81586782>] rtnl_lock+0x12/0x20 >> #1: (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] >> cfg80211_wext_siwfreq+0xbc/0x100 >> >> stack backtrace: >> Pid: 15445, comm: airodump-ng Not tainted 2.6.38-rc5-341cd #4 >> Call Trace: >> [<ffffffff810a3f0a>] ? print_circular_bug+0xfa/0x100 >> [<ffffffff810a7222>] ? __lock_acquire+0x1622/0x1d10 >> [<ffffffff810a1f99>] ? trace_hardirqs_off_caller+0x29/0xc0 >> [<ffffffff810a79d6>] ? lock_acquire+0xc6/0x280 >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 >> [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 >> [<ffffffff816d6bce>] ? mutex_lock_nested+0x6e/0x4b0 >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 >> [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 >> [<ffffffff816b2fad>] ? ioctl_standard_call+0x5d/0xd0 >> [<ffffffff8157818b>] ? __dev_get_by_name+0x9b/0xc0 >> [<ffffffff816b2f50>] ? ioctl_standard_call+0x0/0xd0 >> [<ffffffff816b3223>] ? T.808+0x163/0x170 >> [<ffffffff8112ddf2>] ? might_fault+0x72/0xd0 >> [<ffffffff816b326a>] ? wext_handle_ioctl+0x3a/0x90 >> [<ffffffff8112de3b>] ? might_fault+0xbb/0xd0 >> [<ffffffff815798d2>] ? dev_ioctl+0x6f2/0x830 >> [<ffffffff810a1bae>] ? put_lock_stats+0xe/0x40 >> [<ffffffff810a1c8c>] ? lock_release_holdtime+0xac/0x150 >> [<ffffffff8155cf3d>] ? sock_ioctl+0xfd/0x290 >> [<ffffffff8117dffd>] ? do_vfs_ioctl+0x9d/0x590 >> [<ffffffff8116c8ff>] ? fget_light+0x1df/0x3c0 >> [<ffffffff8117e53a>] ? sys_ioctl+0x4a/0x80 >> [<ffffffff81003192>] ? system_call_fastpath+0x16/0x1b >> >> --- [2] >> >> diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c >> index 3e5dbd4..d112f03 100644 >> --- a/net/wireless/wext-compat.c >> +++ b/net/wireless/wext-compat.c >> @@ -802,11 +802,11 @@ int cfg80211_wext_siwfreq(struct net_device *dev, >> return freq; >> if (freq == 0) >> return -EINVAL; >> - wdev_lock(wdev); >> mutex_lock(&rdev->devlist_mtx); >> + wdev_lock(wdev); >> err = cfg80211_set_freq(rdev, wdev, freq, NL80211_CHAN_NO_HT); >> - mutex_unlock(&rdev->devlist_mtx); >> wdev_unlock(wdev); >> + mutex_unlock(&rdev->devlist_mtx); >> return err; >> default: >> return -EOPNOTSUPP; Please consider for -stable. This patch resolves the lock ordering case my test exposed, and passes lockdep and extended testing. Thanks, Daniel -- Daniel J Blueman ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [stable] [2.6.38-rc5, patch] fix cfg80211_wext_siwfreq lock ordering... 2011-02-22 1:15 ` Daniel J Blueman @ 2011-02-22 20:02 ` Greg KH 2011-02-22 20:21 ` John W. Linville 0 siblings, 1 reply; 6+ messages in thread From: Greg KH @ 2011-02-22 20:02 UTC (permalink / raw) To: Daniel J Blueman; +Cc: stable, Johannes Berg, linux-wireless, Linux Kernel On Tue, Feb 22, 2011 at 09:15:47AM +0800, Daniel J Blueman wrote: > On 22 February 2011 00:25, Johannes Berg <johannes@sipsolutions.net> wrote: > > On Tue, 2011-02-22 at 00:11 +0800, Daniel J Blueman wrote: > >> I previously managed to reproduce a hang while scanning wireless > >> channels (reproducible with airodump-ng hopping channels); subsequent > >> lockdep instrumentation revealed a lock ordering issue [1]. > >> > >> Without knowing the design intent, it looks like the locks should be > >> taken in reverse order; please comment. > >> > >> Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> > >> > >> --- [1] > > > > Yeah, looks this way, thanks. > > > > Acked-by: Johannes Berg <johannes@sipsolutions.net> > > > >> ======================================================= > >> [ INFO: possible circular locking dependency detected ] > >> 2.6.38-rc5-341cd #4 > >> ------------------------------------------------------- > >> airodump-ng/15445 is trying to acquire lock: > >> (&rdev->devlist_mtx){+.+.+.}, at: [<ffffffff816b1266>] > >> cfg80211_wext_siwfreq+0xc6/0x100 > >> > >> but task is already holding lock: > >> (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] cfg80211_wext_siwfreq+0xbc/0x100 > >> > >> which lock already depends on the new lock. > >> > >> the existing dependency chain (in reverse order) is: > >> > >> -> #1 (&wdev->mtx){+.+.+.}: > >> [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 > >> [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 > >> [<ffffffff81696080>] cfg80211_netdev_notifier_call+0x430/0x5f0 > >> [<ffffffff8109351b>] notifier_call_chain+0x8b/0x100 > >> [<ffffffff810935b1>] raw_notifier_call_chain+0x11/0x20 > >> [<ffffffff81576d92>] call_netdevice_notifiers+0x32/0x60 > >> [<ffffffff815771a4>] __dev_notify_flags+0x34/0x80 > >> [<ffffffff81577230>] dev_change_flags+0x40/0x70 > >> [<ffffffff8158587c>] do_setlink+0x1fc/0x8d0 > >> [<ffffffff81586042>] rtnl_setlink+0xf2/0x140 > >> [<ffffffff81586923>] rtnetlink_rcv_msg+0x163/0x270 > >> [<ffffffff8159d741>] netlink_rcv_skb+0xa1/0xd0 > >> [<ffffffff815867b0>] rtnetlink_rcv+0x20/0x30 > >> [<ffffffff8159d39a>] netlink_unicast+0x2ba/0x300 > >> [<ffffffff8159dd57>] netlink_sendmsg+0x267/0x3e0 > >> [<ffffffff8155e364>] sock_sendmsg+0xe4/0x110 > >> [<ffffffff8155f3a3>] sys_sendmsg+0x253/0x3b0 > >> [<ffffffff81003192>] system_call_fastpath+0x16/0x1b > >> > >> -> #0 (&rdev->devlist_mtx){+.+.+.}: > >> [<ffffffff810a7222>] __lock_acquire+0x1622/0x1d10 > >> [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 > >> [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 > >> [<ffffffff816b1266>] cfg80211_wext_siwfreq+0xc6/0x100 > >> [<ffffffff816b2fad>] ioctl_standard_call+0x5d/0xd0 > >> [<ffffffff816b3223>] T.808+0x163/0x170 > >> [<ffffffff816b326a>] wext_handle_ioctl+0x3a/0x90 > >> [<ffffffff815798d2>] dev_ioctl+0x6f2/0x830 > >> [<ffffffff8155cf3d>] sock_ioctl+0xfd/0x290 > >> [<ffffffff8117dffd>] do_vfs_ioctl+0x9d/0x590 > >> [<ffffffff8117e53a>] sys_ioctl+0x4a/0x80 > >> [<ffffffff81003192>] system_call_fastpath+0x16/0x1b > >> > >> other info that might help us debug this: > >> > >> 2 locks held by airodump-ng/15445: > >> #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff81586782>] rtnl_lock+0x12/0x20 > >> #1: (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] > >> cfg80211_wext_siwfreq+0xbc/0x100 > >> > >> stack backtrace: > >> Pid: 15445, comm: airodump-ng Not tainted 2.6.38-rc5-341cd #4 > >> Call Trace: > >> [<ffffffff810a3f0a>] ? print_circular_bug+0xfa/0x100 > >> [<ffffffff810a7222>] ? __lock_acquire+0x1622/0x1d10 > >> [<ffffffff810a1f99>] ? trace_hardirqs_off_caller+0x29/0xc0 > >> [<ffffffff810a79d6>] ? lock_acquire+0xc6/0x280 > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > >> [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 > >> [<ffffffff816d6bce>] ? mutex_lock_nested+0x6e/0x4b0 > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > >> [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > >> [<ffffffff816b2fad>] ? ioctl_standard_call+0x5d/0xd0 > >> [<ffffffff8157818b>] ? __dev_get_by_name+0x9b/0xc0 > >> [<ffffffff816b2f50>] ? ioctl_standard_call+0x0/0xd0 > >> [<ffffffff816b3223>] ? T.808+0x163/0x170 > >> [<ffffffff8112ddf2>] ? might_fault+0x72/0xd0 > >> [<ffffffff816b326a>] ? wext_handle_ioctl+0x3a/0x90 > >> [<ffffffff8112de3b>] ? might_fault+0xbb/0xd0 > >> [<ffffffff815798d2>] ? dev_ioctl+0x6f2/0x830 > >> [<ffffffff810a1bae>] ? put_lock_stats+0xe/0x40 > >> [<ffffffff810a1c8c>] ? lock_release_holdtime+0xac/0x150 > >> [<ffffffff8155cf3d>] ? sock_ioctl+0xfd/0x290 > >> [<ffffffff8117dffd>] ? do_vfs_ioctl+0x9d/0x590 > >> [<ffffffff8116c8ff>] ? fget_light+0x1df/0x3c0 > >> [<ffffffff8117e53a>] ? sys_ioctl+0x4a/0x80 > >> [<ffffffff81003192>] ? system_call_fastpath+0x16/0x1b > >> > >> --- [2] > >> > >> diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c > >> index 3e5dbd4..d112f03 100644 > >> --- a/net/wireless/wext-compat.c > >> +++ b/net/wireless/wext-compat.c > >> @@ -802,11 +802,11 @@ int cfg80211_wext_siwfreq(struct net_device *dev, > >> return freq; > >> if (freq == 0) > >> return -EINVAL; > >> - wdev_lock(wdev); > >> mutex_lock(&rdev->devlist_mtx); > >> + wdev_lock(wdev); > >> err = cfg80211_set_freq(rdev, wdev, freq, NL80211_CHAN_NO_HT); > >> - mutex_unlock(&rdev->devlist_mtx); > >> wdev_unlock(wdev); > >> + mutex_unlock(&rdev->devlist_mtx); > >> return err; > >> default: > >> return -EOPNOTSUPP; > > Please consider for -stable. This patch resolves the lock ordering > case my test exposed, and passes lockdep and extended testing. Consider what? What is the git commit id of this patch in Linus's tree? confused, greg k-h ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [stable] [2.6.38-rc5, patch] fix cfg80211_wext_siwfreq lock ordering... 2011-02-22 20:02 ` [stable] " Greg KH @ 2011-02-22 20:21 ` John W. Linville 2011-02-22 20:43 ` Greg KH 0 siblings, 1 reply; 6+ messages in thread From: John W. Linville @ 2011-02-22 20:21 UTC (permalink / raw) To: Greg KH Cc: Daniel J Blueman, stable, Johannes Berg, linux-wireless, Linux Kernel On Tue, Feb 22, 2011 at 12:02:22PM -0800, Greg KH wrote: > On Tue, Feb 22, 2011 at 09:15:47AM +0800, Daniel J Blueman wrote: > > On 22 February 2011 00:25, Johannes Berg <johannes@sipsolutions.net> wrote: > > > On Tue, 2011-02-22 at 00:11 +0800, Daniel J Blueman wrote: > > >> I previously managed to reproduce a hang while scanning wireless > > >> channels (reproducible with airodump-ng hopping channels); subsequent > > >> lockdep instrumentation revealed a lock ordering issue [1]. > > >> > > >> Without knowing the design intent, it looks like the locks should be > > >> taken in reverse order; please comment. > > >> > > >> Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> > > >> > > >> --- [1] > > > > > > Yeah, looks this way, thanks. > > > > > > Acked-by: Johannes Berg <johannes@sipsolutions.net> > > > > > >> ======================================================= > > >> [ INFO: possible circular locking dependency detected ] > > >> 2.6.38-rc5-341cd #4 > > >> ------------------------------------------------------- > > >> airodump-ng/15445 is trying to acquire lock: > > >> (&rdev->devlist_mtx){+.+.+.}, at: [<ffffffff816b1266>] > > >> cfg80211_wext_siwfreq+0xc6/0x100 > > >> > > >> but task is already holding lock: > > >> (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] cfg80211_wext_siwfreq+0xbc/0x100 > > >> > > >> which lock already depends on the new lock. > > >> > > >> the existing dependency chain (in reverse order) is: > > >> > > >> -> #1 (&wdev->mtx){+.+.+.}: > > >> [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 > > >> [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 > > >> [<ffffffff81696080>] cfg80211_netdev_notifier_call+0x430/0x5f0 > > >> [<ffffffff8109351b>] notifier_call_chain+0x8b/0x100 > > >> [<ffffffff810935b1>] raw_notifier_call_chain+0x11/0x20 > > >> [<ffffffff81576d92>] call_netdevice_notifiers+0x32/0x60 > > >> [<ffffffff815771a4>] __dev_notify_flags+0x34/0x80 > > >> [<ffffffff81577230>] dev_change_flags+0x40/0x70 > > >> [<ffffffff8158587c>] do_setlink+0x1fc/0x8d0 > > >> [<ffffffff81586042>] rtnl_setlink+0xf2/0x140 > > >> [<ffffffff81586923>] rtnetlink_rcv_msg+0x163/0x270 > > >> [<ffffffff8159d741>] netlink_rcv_skb+0xa1/0xd0 > > >> [<ffffffff815867b0>] rtnetlink_rcv+0x20/0x30 > > >> [<ffffffff8159d39a>] netlink_unicast+0x2ba/0x300 > > >> [<ffffffff8159dd57>] netlink_sendmsg+0x267/0x3e0 > > >> [<ffffffff8155e364>] sock_sendmsg+0xe4/0x110 > > >> [<ffffffff8155f3a3>] sys_sendmsg+0x253/0x3b0 > > >> [<ffffffff81003192>] system_call_fastpath+0x16/0x1b > > >> > > >> -> #0 (&rdev->devlist_mtx){+.+.+.}: > > >> [<ffffffff810a7222>] __lock_acquire+0x1622/0x1d10 > > >> [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 > > >> [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 > > >> [<ffffffff816b1266>] cfg80211_wext_siwfreq+0xc6/0x100 > > >> [<ffffffff816b2fad>] ioctl_standard_call+0x5d/0xd0 > > >> [<ffffffff816b3223>] T.808+0x163/0x170 > > >> [<ffffffff816b326a>] wext_handle_ioctl+0x3a/0x90 > > >> [<ffffffff815798d2>] dev_ioctl+0x6f2/0x830 > > >> [<ffffffff8155cf3d>] sock_ioctl+0xfd/0x290 > > >> [<ffffffff8117dffd>] do_vfs_ioctl+0x9d/0x590 > > >> [<ffffffff8117e53a>] sys_ioctl+0x4a/0x80 > > >> [<ffffffff81003192>] system_call_fastpath+0x16/0x1b > > >> > > >> other info that might help us debug this: > > >> > > >> 2 locks held by airodump-ng/15445: > > >> #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff81586782>] rtnl_lock+0x12/0x20 > > >> #1: (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] > > >> cfg80211_wext_siwfreq+0xbc/0x100 > > >> > > >> stack backtrace: > > >> Pid: 15445, comm: airodump-ng Not tainted 2.6.38-rc5-341cd #4 > > >> Call Trace: > > >> [<ffffffff810a3f0a>] ? print_circular_bug+0xfa/0x100 > > >> [<ffffffff810a7222>] ? __lock_acquire+0x1622/0x1d10 > > >> [<ffffffff810a1f99>] ? trace_hardirqs_off_caller+0x29/0xc0 > > >> [<ffffffff810a79d6>] ? lock_acquire+0xc6/0x280 > > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > > >> [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 > > >> [<ffffffff816d6bce>] ? mutex_lock_nested+0x6e/0x4b0 > > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > > >> [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 > > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > > >> [<ffffffff816b2fad>] ? ioctl_standard_call+0x5d/0xd0 > > >> [<ffffffff8157818b>] ? __dev_get_by_name+0x9b/0xc0 > > >> [<ffffffff816b2f50>] ? ioctl_standard_call+0x0/0xd0 > > >> [<ffffffff816b3223>] ? T.808+0x163/0x170 > > >> [<ffffffff8112ddf2>] ? might_fault+0x72/0xd0 > > >> [<ffffffff816b326a>] ? wext_handle_ioctl+0x3a/0x90 > > >> [<ffffffff8112de3b>] ? might_fault+0xbb/0xd0 > > >> [<ffffffff815798d2>] ? dev_ioctl+0x6f2/0x830 > > >> [<ffffffff810a1bae>] ? put_lock_stats+0xe/0x40 > > >> [<ffffffff810a1c8c>] ? lock_release_holdtime+0xac/0x150 > > >> [<ffffffff8155cf3d>] ? sock_ioctl+0xfd/0x290 > > >> [<ffffffff8117dffd>] ? do_vfs_ioctl+0x9d/0x590 > > >> [<ffffffff8116c8ff>] ? fget_light+0x1df/0x3c0 > > >> [<ffffffff8117e53a>] ? sys_ioctl+0x4a/0x80 > > >> [<ffffffff81003192>] ? system_call_fastpath+0x16/0x1b > > >> > > >> --- [2] > > >> > > >> diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c > > >> index 3e5dbd4..d112f03 100644 > > >> --- a/net/wireless/wext-compat.c > > >> +++ b/net/wireless/wext-compat.c > > >> @@ -802,11 +802,11 @@ int cfg80211_wext_siwfreq(struct net_device *dev, > > >> return freq; > > >> if (freq == 0) > > >> return -EINVAL; > > >> - wdev_lock(wdev); > > >> mutex_lock(&rdev->devlist_mtx); > > >> + wdev_lock(wdev); > > >> err = cfg80211_set_freq(rdev, wdev, freq, NL80211_CHAN_NO_HT); > > >> - mutex_unlock(&rdev->devlist_mtx); > > >> wdev_unlock(wdev); > > >> + mutex_unlock(&rdev->devlist_mtx); > > >> return err; > > >> default: > > >> return -EOPNOTSUPP; > > > > Please consider for -stable. This patch resolves the lock ordering > > case my test exposed, and passes lockdep and extended testing. > > Consider what? What is the git commit id of this patch in Linus's tree? I just sent this to Dave M. The commit id should be 4f919a3bc54da01db829c520ce4b1fabfde1c3f7 when it hits Linus' tree. Hth! John -- John W. Linville Someday the world will need a hero, and you linville@tuxdriver.com might be all we have. Be ready. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [stable] [2.6.38-rc5, patch] fix cfg80211_wext_siwfreq lock ordering... 2011-02-22 20:21 ` John W. Linville @ 2011-02-22 20:43 ` Greg KH 0 siblings, 0 replies; 6+ messages in thread From: Greg KH @ 2011-02-22 20:43 UTC (permalink / raw) To: John W. Linville Cc: Daniel J Blueman, stable, Johannes Berg, linux-wireless, Linux Kernel On Tue, Feb 22, 2011 at 03:21:46PM -0500, John W. Linville wrote: > On Tue, Feb 22, 2011 at 12:02:22PM -0800, Greg KH wrote: > > On Tue, Feb 22, 2011 at 09:15:47AM +0800, Daniel J Blueman wrote: > > > On 22 February 2011 00:25, Johannes Berg <johannes@sipsolutions.net> wrote: > > > > On Tue, 2011-02-22 at 00:11 +0800, Daniel J Blueman wrote: > > > >> I previously managed to reproduce a hang while scanning wireless > > > >> channels (reproducible with airodump-ng hopping channels); subsequent > > > >> lockdep instrumentation revealed a lock ordering issue [1]. > > > >> > > > >> Without knowing the design intent, it looks like the locks should be > > > >> taken in reverse order; please comment. > > > >> > > > >> Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> > > > >> > > > >> --- [1] > > > > > > > > Yeah, looks this way, thanks. > > > > > > > > Acked-by: Johannes Berg <johannes@sipsolutions.net> > > > > > > > >> ======================================================= > > > >> [ INFO: possible circular locking dependency detected ] > > > >> 2.6.38-rc5-341cd #4 > > > >> ------------------------------------------------------- > > > >> airodump-ng/15445 is trying to acquire lock: > > > >> (&rdev->devlist_mtx){+.+.+.}, at: [<ffffffff816b1266>] > > > >> cfg80211_wext_siwfreq+0xc6/0x100 > > > >> > > > >> but task is already holding lock: > > > >> (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] cfg80211_wext_siwfreq+0xbc/0x100 > > > >> > > > >> which lock already depends on the new lock. > > > >> > > > >> the existing dependency chain (in reverse order) is: > > > >> > > > >> -> #1 (&wdev->mtx){+.+.+.}: > > > >> [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 > > > >> [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 > > > >> [<ffffffff81696080>] cfg80211_netdev_notifier_call+0x430/0x5f0 > > > >> [<ffffffff8109351b>] notifier_call_chain+0x8b/0x100 > > > >> [<ffffffff810935b1>] raw_notifier_call_chain+0x11/0x20 > > > >> [<ffffffff81576d92>] call_netdevice_notifiers+0x32/0x60 > > > >> [<ffffffff815771a4>] __dev_notify_flags+0x34/0x80 > > > >> [<ffffffff81577230>] dev_change_flags+0x40/0x70 > > > >> [<ffffffff8158587c>] do_setlink+0x1fc/0x8d0 > > > >> [<ffffffff81586042>] rtnl_setlink+0xf2/0x140 > > > >> [<ffffffff81586923>] rtnetlink_rcv_msg+0x163/0x270 > > > >> [<ffffffff8159d741>] netlink_rcv_skb+0xa1/0xd0 > > > >> [<ffffffff815867b0>] rtnetlink_rcv+0x20/0x30 > > > >> [<ffffffff8159d39a>] netlink_unicast+0x2ba/0x300 > > > >> [<ffffffff8159dd57>] netlink_sendmsg+0x267/0x3e0 > > > >> [<ffffffff8155e364>] sock_sendmsg+0xe4/0x110 > > > >> [<ffffffff8155f3a3>] sys_sendmsg+0x253/0x3b0 > > > >> [<ffffffff81003192>] system_call_fastpath+0x16/0x1b > > > >> > > > >> -> #0 (&rdev->devlist_mtx){+.+.+.}: > > > >> [<ffffffff810a7222>] __lock_acquire+0x1622/0x1d10 > > > >> [<ffffffff810a79d6>] lock_acquire+0xc6/0x280 > > > >> [<ffffffff816d6bce>] mutex_lock_nested+0x6e/0x4b0 > > > >> [<ffffffff816b1266>] cfg80211_wext_siwfreq+0xc6/0x100 > > > >> [<ffffffff816b2fad>] ioctl_standard_call+0x5d/0xd0 > > > >> [<ffffffff816b3223>] T.808+0x163/0x170 > > > >> [<ffffffff816b326a>] wext_handle_ioctl+0x3a/0x90 > > > >> [<ffffffff815798d2>] dev_ioctl+0x6f2/0x830 > > > >> [<ffffffff8155cf3d>] sock_ioctl+0xfd/0x290 > > > >> [<ffffffff8117dffd>] do_vfs_ioctl+0x9d/0x590 > > > >> [<ffffffff8117e53a>] sys_ioctl+0x4a/0x80 > > > >> [<ffffffff81003192>] system_call_fastpath+0x16/0x1b > > > >> > > > >> other info that might help us debug this: > > > >> > > > >> 2 locks held by airodump-ng/15445: > > > >> #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff81586782>] rtnl_lock+0x12/0x20 > > > >> #1: (&wdev->mtx){+.+.+.}, at: [<ffffffff816b125c>] > > > >> cfg80211_wext_siwfreq+0xbc/0x100 > > > >> > > > >> stack backtrace: > > > >> Pid: 15445, comm: airodump-ng Not tainted 2.6.38-rc5-341cd #4 > > > >> Call Trace: > > > >> [<ffffffff810a3f0a>] ? print_circular_bug+0xfa/0x100 > > > >> [<ffffffff810a7222>] ? __lock_acquire+0x1622/0x1d10 > > > >> [<ffffffff810a1f99>] ? trace_hardirqs_off_caller+0x29/0xc0 > > > >> [<ffffffff810a79d6>] ? lock_acquire+0xc6/0x280 > > > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > > > >> [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 > > > >> [<ffffffff816d6bce>] ? mutex_lock_nested+0x6e/0x4b0 > > > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > > > >> [<ffffffff810a31d7>] ? mark_held_locks+0x67/0x90 > > > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > > > >> [<ffffffff816b1266>] ? cfg80211_wext_siwfreq+0xc6/0x100 > > > >> [<ffffffff816b2fad>] ? ioctl_standard_call+0x5d/0xd0 > > > >> [<ffffffff8157818b>] ? __dev_get_by_name+0x9b/0xc0 > > > >> [<ffffffff816b2f50>] ? ioctl_standard_call+0x0/0xd0 > > > >> [<ffffffff816b3223>] ? T.808+0x163/0x170 > > > >> [<ffffffff8112ddf2>] ? might_fault+0x72/0xd0 > > > >> [<ffffffff816b326a>] ? wext_handle_ioctl+0x3a/0x90 > > > >> [<ffffffff8112de3b>] ? might_fault+0xbb/0xd0 > > > >> [<ffffffff815798d2>] ? dev_ioctl+0x6f2/0x830 > > > >> [<ffffffff810a1bae>] ? put_lock_stats+0xe/0x40 > > > >> [<ffffffff810a1c8c>] ? lock_release_holdtime+0xac/0x150 > > > >> [<ffffffff8155cf3d>] ? sock_ioctl+0xfd/0x290 > > > >> [<ffffffff8117dffd>] ? do_vfs_ioctl+0x9d/0x590 > > > >> [<ffffffff8116c8ff>] ? fget_light+0x1df/0x3c0 > > > >> [<ffffffff8117e53a>] ? sys_ioctl+0x4a/0x80 > > > >> [<ffffffff81003192>] ? system_call_fastpath+0x16/0x1b > > > >> > > > >> --- [2] > > > >> > > > >> diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c > > > >> index 3e5dbd4..d112f03 100644 > > > >> --- a/net/wireless/wext-compat.c > > > >> +++ b/net/wireless/wext-compat.c > > > >> @@ -802,11 +802,11 @@ int cfg80211_wext_siwfreq(struct net_device *dev, > > > >> return freq; > > > >> if (freq == 0) > > > >> return -EINVAL; > > > >> - wdev_lock(wdev); > > > >> mutex_lock(&rdev->devlist_mtx); > > > >> + wdev_lock(wdev); > > > >> err = cfg80211_set_freq(rdev, wdev, freq, NL80211_CHAN_NO_HT); > > > >> - mutex_unlock(&rdev->devlist_mtx); > > > >> wdev_unlock(wdev); > > > >> + mutex_unlock(&rdev->devlist_mtx); > > > >> return err; > > > >> default: > > > >> return -EOPNOTSUPP; > > > > > > Please consider for -stable. This patch resolves the lock ordering > > > case my test exposed, and passes lockdep and extended testing. > > > > Consider what? What is the git commit id of this patch in Linus's tree? > > I just sent this to Dave M. The commit id should be > 4f919a3bc54da01db829c520ce4b1fabfde1c3f7 when it hits Linus' tree. > > Hth! Yes it does, I'll look out for it. thanks, greg k-h ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2011-02-22 20:45 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2011-02-21 16:11 [2.6.38-rc5, patch] fix cfg80211_wext_siwfreq lock ordering Daniel J Blueman 2011-02-21 16:25 ` Johannes Berg 2011-02-22 1:15 ` Daniel J Blueman 2011-02-22 20:02 ` [stable] " Greg KH 2011-02-22 20:21 ` John W. Linville 2011-02-22 20:43 ` Greg KH
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