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igc: Fix LED-related deadlock on driver unbind 

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: ea578703b0 ("igc: Add support for LEDs on i225/i226")
Reported-by: Roman Lozko <lozko.roma@gmail.com>
Closes: https://lore.kernel.org/r/CAEhC_B=ksywxCG_+aQqXUrGEgKq+4mqnSV8EBHOKbC3-Obj9+Q@mail.gmail.com/
Reported-by: "Marek Marczykowski-Górecki" <marmarek@invisiblethingslab.com>
Closes: https://lore.kernel.org/r/ZhRD3cOtz5i-61PB@mail-itl/
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Tested-by: Kurt Kanzenbach <kurt@linutronix.de> # Intel i225
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20240422204503.225448-1-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Lukas Wunner 2024-04-22 13:45:02 -07:00 committed by Jakub Kicinski
parent edd2d250fb
commit c04d1b9ecc
3 changed files with 35 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/net/ethernet/intel/igc/igc.h
View File

@ -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 @@ void igc_ptp_read(struct igc_adapter *adapter, struct timespec64 *ts);
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))

38
drivers/net/ethernet/intel/igc/igc_leds.c
View File

@ -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);
}

3
drivers/net/ethernet/intel/igc/igc_main.c
View File

@ -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.
*/