* [PATCH] ath9k_htc: Add a missing spin_lock_init()
@ 2021-07-27 21:43 Rajat Asthana
2021-07-28 7:11 ` Kalle Valo
0 siblings, 1 reply; 7+ messages in thread
From: Rajat Asthana @ 2021-07-27 21:43 UTC (permalink / raw)
To: ath9k-devel, kvalo, davem, kuba, linux-wireless, netdev, linux-kernel
Cc: Rajat Asthana
Syzkaller reported a lockdep warning on non-initialized spinlock:
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x143/0x1db lib/dump_stack.c:120
assign_lock_key kernel/locking/lockdep.c:937 [inline]
register_lock_class+0x1077/0x1180 kernel/locking/lockdep.c:1249
__lock_acquire+0x102/0x5230 kernel/locking/lockdep.c:4781
lock_acquire kernel/locking/lockdep.c:5512 [inline]
lock_acquire+0x19d/0x700 kernel/locking/lockdep.c:5477
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
spin_lock_bh include/linux/spinlock.h:359 [inline]
ath9k_wmi_event_tasklet+0x231/0x3f0 drivers/net/wireless/ath/ath9k/wmi.c:172
tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
__do_softirq+0x1b0/0x944 kernel/softirq.c:559
run_ksoftirqd kernel/softirq.c:921 [inline]
run_ksoftirqd+0x21/0x50 kernel/softirq.c:913
smpboot_thread_fn+0x3ec/0x870 kernel/smpboot.c:165
kthread+0x38c/0x460 kernel/kthread.c:313
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
We missed a spin_lock_init() in ath9k_wmi_event_tasklet() when the wmi
event is WMI_TXSTATUS_EVENTID. Placing this init here instead of
ath9k_init_wmi() is fine mainly because we need this spinlock when the
event is WMI_TXSTATUS_EVENTID and hence it should be initialized when it
is needed.
Signed-off-by: Rajat Asthana <rajatasthana4@gmail.com>
---
drivers/net/wireless/ath/ath9k/wmi.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
index fe29ad4b9023..446b7ca459df 100644
--- a/drivers/net/wireless/ath/ath9k/wmi.c
+++ b/drivers/net/wireless/ath/ath9k/wmi.c
@@ -169,6 +169,7 @@ void ath9k_wmi_event_tasklet(struct tasklet_struct *t)
&wmi->drv_priv->fatal_work);
break;
case WMI_TXSTATUS_EVENTID:
+ spin_lock_init(&priv->tx.tx_lock);
spin_lock_bh(&priv->tx.tx_lock);
if (priv->tx.flags & ATH9K_HTC_OP_TX_DRAIN) {
spin_unlock_bh(&priv->tx.tx_lock);
--
2.32.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH] ath9k_htc: Add a missing spin_lock_init()
2021-07-27 21:43 [PATCH] ath9k_htc: Add a missing spin_lock_init() Rajat Asthana
@ 2021-07-28 7:11 ` Kalle Valo
2021-07-28 19:02 ` Rajat Asthana
0 siblings, 1 reply; 7+ messages in thread
From: Kalle Valo @ 2021-07-28 7:11 UTC (permalink / raw)
To: Rajat Asthana
Cc: ath9k-devel, davem, kuba, linux-wireless, netdev, linux-kernel
Rajat Asthana <rajatasthana4@gmail.com> writes:
> Syzkaller reported a lockdep warning on non-initialized spinlock:
>
> INFO: trying to register non-static key.
> The code is fine but needs lockdep annotation, or maybe
> you didn't initialize this object before use?
> turning off the locking correctness validator.
> CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.13.0-rc4-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:79 [inline]
> dump_stack+0x143/0x1db lib/dump_stack.c:120
> assign_lock_key kernel/locking/lockdep.c:937 [inline]
> register_lock_class+0x1077/0x1180 kernel/locking/lockdep.c:1249
> __lock_acquire+0x102/0x5230 kernel/locking/lockdep.c:4781
> lock_acquire kernel/locking/lockdep.c:5512 [inline]
> lock_acquire+0x19d/0x700 kernel/locking/lockdep.c:5477
> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
> _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
> spin_lock_bh include/linux/spinlock.h:359 [inline]
> ath9k_wmi_event_tasklet+0x231/0x3f0 drivers/net/wireless/ath/ath9k/wmi.c:172
> tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
> __do_softirq+0x1b0/0x944 kernel/softirq.c:559
> run_ksoftirqd kernel/softirq.c:921 [inline]
> run_ksoftirqd+0x21/0x50 kernel/softirq.c:913
> smpboot_thread_fn+0x3ec/0x870 kernel/smpboot.c:165
> kthread+0x38c/0x460 kernel/kthread.c:313
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
>
> We missed a spin_lock_init() in ath9k_wmi_event_tasklet() when the wmi
> event is WMI_TXSTATUS_EVENTID. Placing this init here instead of
> ath9k_init_wmi() is fine mainly because we need this spinlock when the
> event is WMI_TXSTATUS_EVENTID and hence it should be initialized when it
> is needed.
>
> Signed-off-by: Rajat Asthana <rajatasthana4@gmail.com>
> ---
> drivers/net/wireless/ath/ath9k/wmi.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
> index fe29ad4b9023..446b7ca459df 100644
> --- a/drivers/net/wireless/ath/ath9k/wmi.c
> +++ b/drivers/net/wireless/ath/ath9k/wmi.c
> @@ -169,6 +169,7 @@ void ath9k_wmi_event_tasklet(struct tasklet_struct *t)
> &wmi->drv_priv->fatal_work);
> break;
> case WMI_TXSTATUS_EVENTID:
> + spin_lock_init(&priv->tx.tx_lock);
> spin_lock_bh(&priv->tx.tx_lock);
> if (priv->tx.flags & ATH9K_HTC_OP_TX_DRAIN) {
> spin_unlock_bh(&priv->tx.tx_lock);
This is not making sense to me. You need to elaborate in the commit log
a lot more why this is "fine". For example, what happens when there are
multiple WMI_TXSTATUS_EVENTID events?
Did you test this on a real device?
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] ath9k_htc: Add a missing spin_lock_init()
2021-07-28 7:11 ` Kalle Valo
@ 2021-07-28 19:02 ` Rajat Asthana
2021-07-28 19:25 ` [PATCH v2] " Rajat Asthana
2021-07-29 7:40 ` [PATCH] " Kalle Valo
0 siblings, 2 replies; 7+ messages in thread
From: Rajat Asthana @ 2021-07-28 19:02 UTC (permalink / raw)
To: Kalle Valo; +Cc: ath9k-devel, davem, kuba, linux-wireless, netdev, linux-kernel
On 28/07/21 12:41 pm, Kalle Valo wrote:
> Rajat Asthana <rajatasthana4@gmail.com> writes:
>
>> Syzkaller reported a lockdep warning on non-initialized spinlock:
>>
>> INFO: trying to register non-static key.
>> The code is fine but needs lockdep annotation, or maybe
>> you didn't initialize this object before use?
>> turning off the locking correctness validator.
>> CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.13.0-rc4-syzkaller #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
>> Call Trace:
>> __dump_stack lib/dump_stack.c:79 [inline]
>> dump_stack+0x143/0x1db lib/dump_stack.c:120
>> assign_lock_key kernel/locking/lockdep.c:937 [inline]
>> register_lock_class+0x1077/0x1180 kernel/locking/lockdep.c:1249
>> __lock_acquire+0x102/0x5230 kernel/locking/lockdep.c:4781
>> lock_acquire kernel/locking/lockdep.c:5512 [inline]
>> lock_acquire+0x19d/0x700 kernel/locking/lockdep.c:5477
>> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
>> _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
>> spin_lock_bh include/linux/spinlock.h:359 [inline]
>> ath9k_wmi_event_tasklet+0x231/0x3f0 drivers/net/wireless/ath/ath9k/wmi.c:172
>> tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
>> __do_softirq+0x1b0/0x944 kernel/softirq.c:559
>> run_ksoftirqd kernel/softirq.c:921 [inline]
>> run_ksoftirqd+0x21/0x50 kernel/softirq.c:913
>> smpboot_thread_fn+0x3ec/0x870 kernel/smpboot.c:165
>> kthread+0x38c/0x460 kernel/kthread.c:313
>> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
>>
>> We missed a spin_lock_init() in ath9k_wmi_event_tasklet() when the wmi
>> event is WMI_TXSTATUS_EVENTID. Placing this init here instead of
>> ath9k_init_wmi() is fine mainly because we need this spinlock when the
>> event is WMI_TXSTATUS_EVENTID and hence it should be initialized when it
>> is needed.
>>
>> Signed-off-by: Rajat Asthana <rajatasthana4@gmail.com>
>> ---
>> drivers/net/wireless/ath/ath9k/wmi.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
>> index fe29ad4b9023..446b7ca459df 100644
>> --- a/drivers/net/wireless/ath/ath9k/wmi.c
>> +++ b/drivers/net/wireless/ath/ath9k/wmi.c
>> @@ -169,6 +169,7 @@ void ath9k_wmi_event_tasklet(struct tasklet_struct *t)
>> &wmi->drv_priv->fatal_work);
>> break;
>> case WMI_TXSTATUS_EVENTID:
>> + spin_lock_init(&priv->tx.tx_lock);
>> spin_lock_bh(&priv->tx.tx_lock);
>> if (priv->tx.flags & ATH9K_HTC_OP_TX_DRAIN) {
>> spin_unlock_bh(&priv->tx.tx_lock);
>
> This is not making sense to me. You need to elaborate in the commit log
> a lot more why this is "fine". For example, what happens when there are
> multiple WMI_TXSTATUS_EVENTID events?
>
Thanks for the review!
Now that you mentioned the case when there are multiple
WMI_TXSTATUS_EVENTID events, this doesn't make sense, as that will cause
a race condition. This instead should be done in ath9k_init_wmi(). I
will make this change in the v2 patch.
> Did you test this on a real device?
>
No, I didn't test this on a real device. Syzkaller has a reproducer for
this and I just relied on the fact that the reproducer did not reproduce
the warning with this patch.
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH v2] ath9k_htc: Add a missing spin_lock_init()
2021-07-28 19:02 ` Rajat Asthana
@ 2021-07-28 19:25 ` Rajat Asthana
2021-07-29 7:41 ` Kalle Valo
2021-12-20 15:50 ` Kalle Valo
2021-07-29 7:40 ` [PATCH] " Kalle Valo
1 sibling, 2 replies; 7+ messages in thread
From: Rajat Asthana @ 2021-07-28 19:25 UTC (permalink / raw)
To: ath9k-devel, kvalo, davem, kuba, linux-wireless, netdev, linux-kernel
Cc: Rajat Asthana
Syzkaller reported a lockdep warning on non-initialized spinlock:
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x143/0x1db lib/dump_stack.c:120
assign_lock_key kernel/locking/lockdep.c:937 [inline]
register_lock_class+0x1077/0x1180 kernel/locking/lockdep.c:1249
__lock_acquire+0x102/0x5230 kernel/locking/lockdep.c:4781
lock_acquire kernel/locking/lockdep.c:5512 [inline]
lock_acquire+0x19d/0x700 kernel/locking/lockdep.c:5477
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
spin_lock_bh include/linux/spinlock.h:359 [inline]
ath9k_wmi_event_tasklet+0x231/0x3f0 drivers/net/wireless/ath/ath9k/wmi.c:172
tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
__do_softirq+0x1b0/0x944 kernel/softirq.c:559
run_ksoftirqd kernel/softirq.c:921 [inline]
run_ksoftirqd+0x21/0x50 kernel/softirq.c:913
smpboot_thread_fn+0x3ec/0x870 kernel/smpboot.c:165
kthread+0x38c/0x460 kernel/kthread.c:313
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
We missed a spin_lock_init() in ath9k_wmi_event_tasklet() when the wmi
event is WMI_TXSTATUS_EVENTID. So, add a spin_lock_init() in
ath9k_init_wmi().
Signed-off-by: Rajat Asthana <rajatasthana4@gmail.com>
---
drivers/net/wireless/ath/ath9k/wmi.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
index fe29ad4b9023..480de2170816 100644
--- a/drivers/net/wireless/ath/ath9k/wmi.c
+++ b/drivers/net/wireless/ath/ath9k/wmi.c
@@ -101,6 +101,7 @@ struct wmi *ath9k_init_wmi(struct ath9k_htc_priv *priv)
skb_queue_head_init(&wmi->wmi_event_queue);
spin_lock_init(&wmi->wmi_lock);
spin_lock_init(&wmi->event_lock);
+ spin_lock_init(&wmi->drv_priv->tx.tx_lock);
mutex_init(&wmi->op_mutex);
mutex_init(&wmi->multi_write_mutex);
mutex_init(&wmi->multi_rmw_mutex);
--
2.32.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2] ath9k_htc: Add a missing spin_lock_init()
2021-07-28 19:25 ` [PATCH v2] " Rajat Asthana
@ 2021-07-29 7:41 ` Kalle Valo
2021-12-20 15:50 ` Kalle Valo
1 sibling, 0 replies; 7+ messages in thread
From: Kalle Valo @ 2021-07-29 7:41 UTC (permalink / raw)
To: Rajat Asthana
Cc: ath9k-devel, davem, kuba, linux-wireless, netdev, linux-kernel
Rajat Asthana <rajatasthana4@gmail.com> writes:
> Syzkaller reported a lockdep warning on non-initialized spinlock:
>
> INFO: trying to register non-static key.
> The code is fine but needs lockdep annotation, or maybe
> you didn't initialize this object before use?
> turning off the locking correctness validator.
> CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.13.0-rc4-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:79 [inline]
> dump_stack+0x143/0x1db lib/dump_stack.c:120
> assign_lock_key kernel/locking/lockdep.c:937 [inline]
> register_lock_class+0x1077/0x1180 kernel/locking/lockdep.c:1249
> __lock_acquire+0x102/0x5230 kernel/locking/lockdep.c:4781
> lock_acquire kernel/locking/lockdep.c:5512 [inline]
> lock_acquire+0x19d/0x700 kernel/locking/lockdep.c:5477
> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
> _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
> spin_lock_bh include/linux/spinlock.h:359 [inline]
> ath9k_wmi_event_tasklet+0x231/0x3f0 drivers/net/wireless/ath/ath9k/wmi.c:172
> tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
> __do_softirq+0x1b0/0x944 kernel/softirq.c:559
> run_ksoftirqd kernel/softirq.c:921 [inline]
> run_ksoftirqd+0x21/0x50 kernel/softirq.c:913
> smpboot_thread_fn+0x3ec/0x870 kernel/smpboot.c:165
> kthread+0x38c/0x460 kernel/kthread.c:313
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
>
> We missed a spin_lock_init() in ath9k_wmi_event_tasklet() when the wmi
> event is WMI_TXSTATUS_EVENTID. So, add a spin_lock_init() in
> ath9k_init_wmi().
>
> Signed-off-by: Rajat Asthana <rajatasthana4@gmail.com>
I assume this version is also not tested on a real device. Can someone
review and/or test this, please?
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] ath9k_htc: Add a missing spin_lock_init()
2021-07-28 19:25 ` [PATCH v2] " Rajat Asthana
2021-07-29 7:41 ` Kalle Valo
@ 2021-12-20 15:50 ` Kalle Valo
1 sibling, 0 replies; 7+ messages in thread
From: Kalle Valo @ 2021-12-20 15:50 UTC (permalink / raw)
To: Rajat Asthana
Cc: ath9k-devel, kvalo, davem, kuba, linux-wireless, netdev,
linux-kernel, Rajat Asthana
Rajat Asthana <rajatasthana4@gmail.com> wrote:
> Syzkaller reported a lockdep warning on non-initialized spinlock:
>
> INFO: trying to register non-static key.
> The code is fine but needs lockdep annotation, or maybe
> you didn't initialize this object before use?
> turning off the locking correctness validator.
> CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.13.0-rc4-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:79 [inline]
> dump_stack+0x143/0x1db lib/dump_stack.c:120
> assign_lock_key kernel/locking/lockdep.c:937 [inline]
> register_lock_class+0x1077/0x1180 kernel/locking/lockdep.c:1249
> __lock_acquire+0x102/0x5230 kernel/locking/lockdep.c:4781
> lock_acquire kernel/locking/lockdep.c:5512 [inline]
> lock_acquire+0x19d/0x700 kernel/locking/lockdep.c:5477
> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
> _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
> spin_lock_bh include/linux/spinlock.h:359 [inline]
> ath9k_wmi_event_tasklet+0x231/0x3f0 drivers/net/wireless/ath/ath9k/wmi.c:172
> tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
> __do_softirq+0x1b0/0x944 kernel/softirq.c:559
> run_ksoftirqd kernel/softirq.c:921 [inline]
> run_ksoftirqd+0x21/0x50 kernel/softirq.c:913
> smpboot_thread_fn+0x3ec/0x870 kernel/smpboot.c:165
> kthread+0x38c/0x460 kernel/kthread.c:313
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
>
> We missed a spin_lock_init() in ath9k_wmi_event_tasklet() when the wmi
> event is WMI_TXSTATUS_EVENTID. So, add a spin_lock_init() in
> ath9k_init_wmi().
>
> Signed-off-by: Rajat Asthana <rajatasthana4@gmail.com>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
The lock is already initialised in ath9k_init_priv(), so now the same lock is
initialised twice. ath9k_init_wmi() is called before ath9k_init_priv(), so it
looks like we have a race somewhere.
Patch set to Changes Requested.
--
https://patchwork.kernel.org/project/linux-wireless/patch/20210728192533.18727-1-rajatasthana4@gmail.com/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] ath9k_htc: Add a missing spin_lock_init()
2021-07-28 19:02 ` Rajat Asthana
2021-07-28 19:25 ` [PATCH v2] " Rajat Asthana
@ 2021-07-29 7:40 ` Kalle Valo
1 sibling, 0 replies; 7+ messages in thread
From: Kalle Valo @ 2021-07-29 7:40 UTC (permalink / raw)
To: Rajat Asthana
Cc: ath9k-devel, davem, kuba, linux-wireless, netdev, linux-kernel
Rajat Asthana <rajatasthana4@gmail.com> writes:
>> Did you test this on a real device?
>
> No, I didn't test this on a real device. Syzkaller has a reproducer
> for this and I just relied on the fact that the reproducer did not
> reproduce the warning with this patch.
This is exactly what worries me with syzbot patches. People just try to
silence the warning and not thinking how it works on a real device.
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-12-20 15:50 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-27 21:43 [PATCH] ath9k_htc: Add a missing spin_lock_init() Rajat Asthana
2021-07-28 7:11 ` Kalle Valo
2021-07-28 19:02 ` Rajat Asthana
2021-07-28 19:25 ` [PATCH v2] " Rajat Asthana
2021-07-29 7:41 ` Kalle Valo
2021-12-20 15:50 ` Kalle Valo
2021-07-29 7:40 ` [PATCH] " Kalle Valo
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