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Message-Id: <20220818165558.997984-1-ivecera@redhat.com>
Date: Thu, 18 Aug 2022 18:55:58 +0200
From: Ivan Vecera <ivecera@...hat.com>
To: netdev@...r.kernel.org
Cc: Jacob Keller <jacob.e.keller@...el.com>,
Patryk Piotrowski <patryk.piotrowski@...el.com>,
Vitaly Grinberg <vgrinber@...hat.com>,
Jesse Brandeburg <jesse.brandeburg@...el.com>,
Tony Nguyen <anthony.l.nguyen@...el.com>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
intel-wired-lan@...ts.osuosl.org (moderated list:INTEL ETHERNET DRIVERS),
linux-kernel@...r.kernel.org (open list)
Subject: [PATCH net] iavf: Detach device during reset task
iavf_reset_task() takes crit_lock at the beginning and holds
it during whole call. The function subsequently calls
iavf_init_interrupt_scheme() that grabs RTNL. Problem occurs
when userspace initiates during the reset task any ndo callback
that runs under RTNL like iavf_open() because some of that
functions tries to take crit_lock. This leads to classic A-B B-A
deadlock scenario.
To resolve this situation the device should be detached in
iavf_reset_task() prior taking crit_lock to avoid subsequent
ndos running under RTNL and reattach the device at the end.
Fixes: 62fe2a865e6d ("i40evf: add missing rtnl_lock() around i40evf_set_interrupt_capability")
Cc: Jacob Keller <jacob.e.keller@...el.com>
Cc: Patryk Piotrowski <patryk.piotrowski@...el.com>
Tested-by: Vitaly Grinberg <vgrinber@...hat.com>
Signed-off-by: Ivan Vecera <ivecera@...hat.com>
---
drivers/net/ethernet/intel/iavf/iavf_main.c | 22 +++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index f39440ad5c50..ee8f911b57ea 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -2877,6 +2877,13 @@ static void iavf_reset_task(struct work_struct *work)
int i = 0, err;
bool running;
+ /*
+ * Detach interface to avoid subsequent NDO callbacks
+ */
+ rtnl_lock();
+ netif_device_detach(netdev);
+ rtnl_unlock();
+
/* When device is being removed it doesn't make sense to run the reset
* task, just return in such a case.
*/
@@ -2884,7 +2891,7 @@ static void iavf_reset_task(struct work_struct *work)
if (adapter->state != __IAVF_REMOVE)
queue_work(iavf_wq, &adapter->reset_task);
- return;
+ goto reset_finish;
}
while (!mutex_trylock(&adapter->client_lock))
@@ -2954,7 +2961,6 @@ static void iavf_reset_task(struct work_struct *work)
if (running) {
netif_carrier_off(netdev);
- netif_tx_stop_all_queues(netdev);
adapter->link_up = false;
iavf_napi_disable_all(adapter);
}
@@ -3081,10 +3087,8 @@ static void iavf_reset_task(struct work_struct *work)
adapter->flags &= ~IAVF_FLAG_REINIT_ITR_NEEDED;
- mutex_unlock(&adapter->client_lock);
- mutex_unlock(&adapter->crit_lock);
+ goto reset_finish;
- return;
reset_err:
if (running) {
set_bit(__IAVF_VSI_DOWN, adapter->vsi.state);
@@ -3092,9 +3096,15 @@ static void iavf_reset_task(struct work_struct *work)
}
iavf_disable_vf(adapter);
+ dev_err(&adapter->pdev->dev, "failed to allocate resources during reinit\n");
+
+reset_finish:
mutex_unlock(&adapter->client_lock);
mutex_unlock(&adapter->crit_lock);
- dev_err(&adapter->pdev->dev, "failed to allocate resources during reinit\n");
+
+ rtnl_lock();
+ netif_device_attach(netdev);
+ rtnl_unlock();
}
/**
--
2.35.1
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