Roman reports a deadlock on unplug of a Thunderbolt docking station
containing an Intel I225 Ethernet adapter.
The root cause is that led_classdev's for LEDs on the adapter are
registered such that they're device-managed by the netdev. That
results in recursive acquisition of the rtnl_lock() mutex on unplug:
When the driver calls unregister_netdev(), it acquires rtnl_lock(),
then frees the device-managed resources. Upon unregistering the LEDs,
netdev_trig_deactivate() invokes unregister_netdevice_notifier(),
which tries to acquire rtnl_lock() again.
Avoid by using non-device-managed LED registration.
Stack trace for posterity:
schedule+0x6e/0xf0
schedule_preempt_disabled+0x15/0x20
__mutex_lock+0x2a0/0x750
unregister_netdevice_notifier+0x40/0x150
netdev_trig_deactivate+0x1f/0x60 [ledtrig_netdev]
led_trigger_set+0x102/0x330
led_classdev_unregister+0x4b/0x110
release_nodes+0x3d/0xb0
devres_release_all+0x8b/0xc0
device_del+0x34f/0x3c0
unregister_netdevice_many_notify+0x80b/0xaf0
unregister_netdev+0x7c/0xd0
igc_remove+0xd8/0x1e0 [igc]
pci_device_remove+0x3f/0xb0
Fixes: ea578703b03d ("igc: Add support for LEDs on i225/i226")
Reported-by: Roman Lozko <[email protected]>
Closes:
https://lore.kernel.org/r/CAEhC_B=ksywxcg_+aqqxurgegkq+4mqnsv8ebhokbc3-obj...@mail.gmail.com/
Signed-off-by: Kurt Kanzenbach <[email protected]>
Signed-off-by: Lukas Wunner <[email protected]>
Cc: Heiner Kallweit <[email protected]>
---
drivers/net/ethernet/intel/igc/igc.h | 2 ++
drivers/net/ethernet/intel/igc/igc_leds.c | 38 ++++++++++++++++++++++++-------
drivers/net/ethernet/intel/igc/igc_main.c | 3 +++
3 files changed, 35 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/intel/igc/igc.h
b/drivers/net/ethernet/intel/igc/igc.h
index 90316dc..6bc56c7 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -298,6 +298,7 @@ struct igc_adapter {
/* LEDs */
struct mutex led_mutex;
+ struct igc_led_classdev *leds;
};
void igc_up(struct igc_adapter *adapter);
@@ -723,6 +724,7 @@ struct igc_nfc_rule *igc_get_nfc_rule(struct igc_adapter
*adapter,
void igc_ptp_tx_tstamp_event(struct igc_adapter *adapter);
int igc_led_setup(struct igc_adapter *adapter);
+void igc_led_free(struct igc_adapter *adapter);
#define igc_rx_pg_size(_ring) (PAGE_SIZE << igc_rx_pg_order(_ring))
diff --git a/drivers/net/ethernet/intel/igc/igc_leds.c
b/drivers/net/ethernet/intel/igc/igc_leds.c
index bf240c5..3929b25 100644
--- a/drivers/net/ethernet/intel/igc/igc_leds.c
+++ b/drivers/net/ethernet/intel/igc/igc_leds.c
@@ -236,8 +236,8 @@ static void igc_led_get_name(struct igc_adapter *adapter,
int index, char *buf,
pci_dev_id(adapter->pdev), index);
}
-static void igc_setup_ldev(struct igc_led_classdev *ldev,
- struct net_device *netdev, int index)
+static int igc_setup_ldev(struct igc_led_classdev *ldev,
+ struct net_device *netdev, int index)
{
struct igc_adapter *adapter = netdev_priv(netdev);
struct led_classdev *led_cdev = &ldev->led;
@@ -257,24 +257,46 @@ static void igc_setup_ldev(struct igc_led_classdev *ldev,
led_cdev->hw_control_get = igc_led_hw_control_get;
led_cdev->hw_control_get_device = igc_led_hw_control_get_device;
- devm_led_classdev_register(&netdev->dev, led_cdev);
+ return led_classdev_register(&netdev->dev, led_cdev);
}
int igc_led_setup(struct igc_adapter *adapter)
{
struct net_device *netdev = adapter->netdev;
- struct device *dev = &netdev->dev;
struct igc_led_classdev *leds;
- int i;
+ int i, err;
mutex_init(&adapter->led_mutex);
- leds = devm_kcalloc(dev, IGC_NUM_LEDS, sizeof(*leds), GFP_KERNEL);
+ leds = kcalloc(IGC_NUM_LEDS, sizeof(*leds), GFP_KERNEL);
if (!leds)
return -ENOMEM;
- for (i = 0; i < IGC_NUM_LEDS; i++)
- igc_setup_ldev(leds + i, netdev, i);
+ for (i = 0; i < IGC_NUM_LEDS; i++) {
+ err = igc_setup_ldev(leds + i, netdev, i);
+ if (err)
+ goto err;
+ }
+
+ adapter->leds = leds;
return 0;
+
+err:
+ for (i--; i >= 0; i--)
+ led_classdev_unregister(&((leds + i)->led));
+
+ kfree(leds);
+ return err;
+}
+
+void igc_led_free(struct igc_adapter *adapter)
+{
+ struct igc_led_classdev *leds = adapter->leds;
+ int i;
+
+ for (i = 0; i < IGC_NUM_LEDS; i++)
+ led_classdev_unregister(&((leds + i)->led));
+
+ kfree(leds);
}
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
b/drivers/net/ethernet/intel/igc/igc_main.c
index 35ad40a..4d975d6 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -7021,6 +7021,9 @@ static void igc_remove(struct pci_dev *pdev)
cancel_work_sync(&adapter->watchdog_task);
hrtimer_cancel(&adapter->hrtimer);
+ if (IS_ENABLED(CONFIG_IGC_LEDS))
+ igc_led_free(adapter);
+
/* Release control of h/w to f/w. If f/w is AMT enabled, this
* would have already happened in close and is redundant.
*/
--
2.43.0
