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* 2.6.35-rc2-git1 - net/mac80211/sta_info.c:125 invoked rcu_dereference_check() without protection!
@ 2010-06-07 18:25 Miles Lane
  2010-06-07 23:59 ` Paul E. McKenney
  0 siblings, 1 reply; 5+ messages in thread
From: Miles Lane @ 2010-06-07 18:25 UTC (permalink / raw)
  To: paulmck
  Cc: Vivek Goyal, Eric Paris, Lai Jiangshan, Ingo Molnar,
	Peter Zijlstra, LKML, nauman, eric.dumazet, netdev, Jens Axboe,
	Gui Jianfeng, Li Zefan, Johannes Berg

[   43.478812] [ INFO: suspicious rcu_dereference_check() usage. ]
[   43.478815] ---------------------------------------------------
[   43.478820] net/mac80211/sta_info.c:125 invoked
rcu_dereference_check() without protection!
[   43.478824]
[   43.478824] other info that might help us debug this:
[   43.478826]
[   43.478829]
[   43.478830] rcu_scheduler_active = 1, debug_locks = 1
[   43.478834] no locks held by NetworkManager/4017.
[   43.478836]
[   43.478837] stack backtrace:
[   43.478842] Pid: 4017, comm: NetworkManager Not tainted 2.6.35-rc2-git1 #8
[   43.478846] Call Trace:
[   43.478849]  <IRQ>  [<ffffffff81064e9c>] lockdep_rcu_dereference+0x9d/0xa5
[   43.478876]  [<ffffffffa010cb3c>] sta_info_get_bss+0x71/0x12d [mac80211]
[   43.478889]  [<ffffffffa010cc0d>] ieee80211_find_sta+0x15/0x2f [mac80211]
[   43.478902]  [<ffffffffa019ae16>] iwlagn_tx_queue_reclaim+0xe7/0x1bb [iwlagn]
[   43.478909]  [<ffffffff8106530b>] ? mark_lock+0x2d/0x262
[   43.478920]  [<ffffffffa019e270>] iwlagn_rx_reply_tx+0x4cd/0x58a [iwlagn]
[   43.478928]  [<ffffffff811ca313>] ? is_swiotlb_buffer+0x2e/0x3b
[   43.478937]  [<ffffffffa0192ec2>] iwl_rx_handle+0x161/0x2bf [iwlagn]
[   43.478946]  [<ffffffffa019370a>] iwl_irq_tasklet+0x2eb/0x408 [iwlagn]
[   43.478953]  [<ffffffff8103f892>] tasklet_action+0xa7/0x10f
[   43.478960]  [<ffffffff810404cf>] __do_softirq+0x148/0x25a
[   43.478966]  [<ffffffff8100314c>] call_softirq+0x1c/0x28
[   43.478972]  [<ffffffff81004d20>] do_softirq+0x38/0x80
[   43.478977]  [<ffffffff8103ffd0>] irq_exit+0x45/0x94
[   43.478983]  [<ffffffff81004465>] do_IRQ+0xad/0xc4
[   43.478989]  [<ffffffff813ca3d3>] ret_from_intr+0x0/0xf
[   43.478993]  <EOI>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: 2.6.35-rc2-git1 - net/mac80211/sta_info.c:125 invoked rcu_dereference_check() without protection!
  2010-06-07 18:25 2.6.35-rc2-git1 - net/mac80211/sta_info.c:125 invoked rcu_dereference_check() without protection! Miles Lane
@ 2010-06-07 23:59 ` Paul E. McKenney
  2010-06-08  7:26   ` Johannes Berg
  0 siblings, 1 reply; 5+ messages in thread
From: Paul E. McKenney @ 2010-06-07 23:59 UTC (permalink / raw)
  To: Miles Lane
  Cc: Vivek Goyal, Eric Paris, Lai Jiangshan, Ingo Molnar,
	Peter Zijlstra, LKML, nauman, eric.dumazet, netdev, Jens Axboe,
	Gui Jianfeng, Li Zefan, Johannes Berg

On Mon, Jun 07, 2010 at 02:25:44PM -0400, Miles Lane wrote:
> [   43.478812] [ INFO: suspicious rcu_dereference_check() usage. ]
> [   43.478815] ---------------------------------------------------
> [   43.478820] net/mac80211/sta_info.c:125 invoked
> rcu_dereference_check() without protection!
> [   43.478824]
> [   43.478824] other info that might help us debug this:
> [   43.478826]
> [   43.478829]
> [   43.478830] rcu_scheduler_active = 1, debug_locks = 1
> [   43.478834] no locks held by NetworkManager/4017.

Hmmm...  Johannes's update has been merged, and it requires that callers
either be in an RCU read-side critical section or hold either the
->sta_lock or the ->sta_mtx, and this thread does none of this.

Johannes, any thoughts?

							Thanx, Paul

> [   43.478837] stack backtrace:
> [   43.478842] Pid: 4017, comm: NetworkManager Not tainted 2.6.35-rc2-git1 #8
> [   43.478846] Call Trace:
> [   43.478849]  <IRQ>  [<ffffffff81064e9c>] lockdep_rcu_dereference+0x9d/0xa5
> [   43.478876]  [<ffffffffa010cb3c>] sta_info_get_bss+0x71/0x12d [mac80211]
> [   43.478889]  [<ffffffffa010cc0d>] ieee80211_find_sta+0x15/0x2f [mac80211]
> [   43.478902]  [<ffffffffa019ae16>] iwlagn_tx_queue_reclaim+0xe7/0x1bb [iwlagn]
> [   43.478909]  [<ffffffff8106530b>] ? mark_lock+0x2d/0x262
> [   43.478920]  [<ffffffffa019e270>] iwlagn_rx_reply_tx+0x4cd/0x58a [iwlagn]
> [   43.478928]  [<ffffffff811ca313>] ? is_swiotlb_buffer+0x2e/0x3b
> [   43.478937]  [<ffffffffa0192ec2>] iwl_rx_handle+0x161/0x2bf [iwlagn]
> [   43.478946]  [<ffffffffa019370a>] iwl_irq_tasklet+0x2eb/0x408 [iwlagn]
> [   43.478953]  [<ffffffff8103f892>] tasklet_action+0xa7/0x10f
> [   43.478960]  [<ffffffff810404cf>] __do_softirq+0x148/0x25a
> [   43.478966]  [<ffffffff8100314c>] call_softirq+0x1c/0x28
> [   43.478972]  [<ffffffff81004d20>] do_softirq+0x38/0x80
> [   43.478977]  [<ffffffff8103ffd0>] irq_exit+0x45/0x94
> [   43.478983]  [<ffffffff81004465>] do_IRQ+0xad/0xc4
> [   43.478989]  [<ffffffff813ca3d3>] ret_from_intr+0x0/0xf
> [   43.478993]  <EOI>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: 2.6.35-rc2-git1 - net/mac80211/sta_info.c:125 invoked rcu_dereference_check() without protection!
  2010-06-07 23:59 ` Paul E. McKenney
@ 2010-06-08  7:26   ` Johannes Berg
  2010-06-08 11:29     ` Miles Lane
  0 siblings, 1 reply; 5+ messages in thread
From: Johannes Berg @ 2010-06-08  7:26 UTC (permalink / raw)
  To: paulmck
  Cc: Miles Lane, Vivek Goyal, Eric Paris, Lai Jiangshan, Ingo Molnar,
	Peter Zijlstra, LKML, nauman, eric.dumazet, netdev, Jens Axboe,
	Gui Jianfeng, Li Zefan

On Mon, 2010-06-07 at 16:59 -0700, Paul E. McKenney wrote:
> On Mon, Jun 07, 2010 at 02:25:44PM -0400, Miles Lane wrote:
> > [   43.478812] [ INFO: suspicious rcu_dereference_check() usage. ]
> > [   43.478815] ---------------------------------------------------
> > [   43.478820] net/mac80211/sta_info.c:125 invoked
> > rcu_dereference_check() without protection!
> > [   43.478824]
> > [   43.478824] other info that might help us debug this:
> > [   43.478826]
> > [   43.478829]
> > [   43.478830] rcu_scheduler_active = 1, debug_locks = 1
> > [   43.478834] no locks held by NetworkManager/4017.
> 
> Hmmm...  Johannes's update has been merged, and it requires that callers
> either be in an RCU read-side critical section or hold either the
> ->sta_lock or the ->sta_mtx, and this thread does none of this.
> 
> Johannes, any thoughts?
> 
> 							Thanx, Paul
> 
> > [   43.478837] stack backtrace:
> > [   43.478842] Pid: 4017, comm: NetworkManager Not tainted 2.6.35-rc2-git1 #8
> > [   43.478846] Call Trace:
> > [   43.478849]  <IRQ>  [<ffffffff81064e9c>] lockdep_rcu_dereference+0x9d/0xa5
> > [   43.478876]  [<ffffffffa010cb3c>] sta_info_get_bss+0x71/0x12d [mac80211]
> > [   43.478889]  [<ffffffffa010cc0d>] ieee80211_find_sta+0x15/0x2f [mac80211]
> > [   43.478902]  [<ffffffffa019ae16>] iwlagn_tx_queue_reclaim+0xe7/0x1bb [iwlagn]

iwlwifi wasn't using rcu protection here -- already sent a patch fixing
it. My mistake, I  think. Thanks for checking :)

johannes

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: 2.6.35-rc2-git1 - net/mac80211/sta_info.c:125 invoked rcu_dereference_check() without protection!
  2010-06-08  7:26   ` Johannes Berg
@ 2010-06-08 11:29     ` Miles Lane
  2010-06-08 16:26       ` Paul E. McKenney
  0 siblings, 1 reply; 5+ messages in thread
From: Miles Lane @ 2010-06-08 11:29 UTC (permalink / raw)
  To: Johannes Berg
  Cc: paulmck, Vivek Goyal, Eric Paris, Lai Jiangshan, Ingo Molnar,
	Peter Zijlstra, LKML, nauman, eric.dumazet, netdev, Jens Axboe,
	Gui Jianfeng, Li Zefan

On Tue, Jun 8, 2010 at 3:26 AM, Johannes Berg <johannes@sipsolutions.net> wrote:
> On Mon, 2010-06-07 at 16:59 -0700, Paul E. McKenney wrote:
>> On Mon, Jun 07, 2010 at 02:25:44PM -0400, Miles Lane wrote:
>> > [   43.478812] [ INFO: suspicious rcu_dereference_check() usage. ]
>> > [   43.478815] ---------------------------------------------------
>> > [   43.478820] net/mac80211/sta_info.c:125 invoked
>> > rcu_dereference_check() without protection!
>> > [   43.478824]
>> > [   43.478824] other info that might help us debug this:
>> > [   43.478826]
>> > [   43.478829]
>> > [   43.478830] rcu_scheduler_active = 1, debug_locks = 1
>> > [   43.478834] no locks held by NetworkManager/4017.
>>
>> Hmmm...  Johannes's update has been merged, and it requires that callers
>> either be in an RCU read-side critical section or hold either the
>> ->sta_lock or the ->sta_mtx, and this thread does none of this.
>>
>> Johannes, any thoughts?
>>
>>                                                       Thanx, Paul
>>
>> > [   43.478837] stack backtrace:
>> > [   43.478842] Pid: 4017, comm: NetworkManager Not tainted 2.6.35-rc2-git1 #8
>> > [   43.478846] Call Trace:
>> > [   43.478849]  <IRQ>  [<ffffffff81064e9c>] lockdep_rcu_dereference+0x9d/0xa5
>> > [   43.478876]  [<ffffffffa010cb3c>] sta_info_get_bss+0x71/0x12d [mac80211]
>> > [   43.478889]  [<ffffffffa010cc0d>] ieee80211_find_sta+0x15/0x2f [mac80211]
>> > [   43.478902]  [<ffffffffa019ae16>] iwlagn_tx_queue_reclaim+0xe7/0x1bb [iwlagn]
>
> iwlwifi wasn't using rcu protection here -- already sent a patch fixing
> it. My mistake, I  think. Thanks for checking :)
>
> johannes
>
>

Yes, your patch works for me.

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: 2.6.35-rc2-git1 - net/mac80211/sta_info.c:125 invoked rcu_dereference_check() without protection!
  2010-06-08 11:29     ` Miles Lane
@ 2010-06-08 16:26       ` Paul E. McKenney
  0 siblings, 0 replies; 5+ messages in thread
From: Paul E. McKenney @ 2010-06-08 16:26 UTC (permalink / raw)
  To: Miles Lane
  Cc: Johannes Berg, Vivek Goyal, Eric Paris, Lai Jiangshan,
	Ingo Molnar, Peter Zijlstra, LKML, nauman, eric.dumazet, netdev,
	Jens Axboe, Gui Jianfeng, Li Zefan

On Tue, Jun 08, 2010 at 07:29:48AM -0400, Miles Lane wrote:
> On Tue, Jun 8, 2010 at 3:26 AM, Johannes Berg <johannes@sipsolutions.net> wrote:
> > On Mon, 2010-06-07 at 16:59 -0700, Paul E. McKenney wrote:
> >> On Mon, Jun 07, 2010 at 02:25:44PM -0400, Miles Lane wrote:
> >> > [   43.478812] [ INFO: suspicious rcu_dereference_check() usage. ]
> >> > [   43.478815] ---------------------------------------------------
> >> > [   43.478820] net/mac80211/sta_info.c:125 invoked
> >> > rcu_dereference_check() without protection!
> >> > [   43.478824]
> >> > [   43.478824] other info that might help us debug this:
> >> > [   43.478826]
> >> > [   43.478829]
> >> > [   43.478830] rcu_scheduler_active = 1, debug_locks = 1
> >> > [   43.478834] no locks held by NetworkManager/4017.
> >>
> >> Hmmm...  Johannes's update has been merged, and it requires that callers
> >> either be in an RCU read-side critical section or hold either the
> >> ->sta_lock or the ->sta_mtx, and this thread does none of this.
> >>
> >> Johannes, any thoughts?
> >>
> >>                                                       Thanx, Paul
> >>
> >> > [   43.478837] stack backtrace:
> >> > [   43.478842] Pid: 4017, comm: NetworkManager Not tainted 2.6.35-rc2-git1 #8
> >> > [   43.478846] Call Trace:
> >> > [   43.478849]  <IRQ>  [<ffffffff81064e9c>] lockdep_rcu_dereference+0x9d/0xa5
> >> > [   43.478876]  [<ffffffffa010cb3c>] sta_info_get_bss+0x71/0x12d [mac80211]
> >> > [   43.478889]  [<ffffffffa010cc0d>] ieee80211_find_sta+0x15/0x2f [mac80211]
> >> > [   43.478902]  [<ffffffffa019ae16>] iwlagn_tx_queue_reclaim+0xe7/0x1bb [iwlagn]
> >
> > iwlwifi wasn't using rcu protection here -- already sent a patch fixing
> > it. My mistake, I  think. Thanks for checking :)
> >
> > johannes
> 
> Yes, your patch works for me.

Thank you both!!!

							Thanx, Paul

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2010-06-08 16:26 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-06-07 18:25 2.6.35-rc2-git1 - net/mac80211/sta_info.c:125 invoked rcu_dereference_check() without protection! Miles Lane
2010-06-07 23:59 ` Paul E. McKenney
2010-06-08  7:26   ` Johannes Berg
2010-06-08 11:29     ` Miles Lane
2010-06-08 16:26       ` Paul E. McKenney

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