From: Kurt Kanzenbach <kurt@linutronix.de>
To: Jesse Brandeburg <jesse.brandeburg@intel.com>,
Tony Nguyen <anthony.l.nguyen@intel.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>, Andrew Lunn <andrew@lunn.ch>
Cc: "Sasha Neftin" <sasha.neftin@intel.com>,
"Roman Lozko" <lozko.roma@gmail.com>,
"Kurt Kanzenbach" <kurt@linutronix.de>,
"Marek Marczykowski-Górecki" <marmarek@invisiblethingslab.com>,
"Lukas Wunner" <lukas@wunner.de>,
intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org
Subject: [Intel-wired-lan] [PATCH iwl-net v2] igc: Fix deadlock on module removal
Date: Mon, 15 Apr 2024 12:59:37 +0200 [thread overview]
Message-ID: <20240411-igc_led_deadlock-v2-1-b758c0c88b2b@linutronix.de> (raw)
From: Lukas Wunner <lukas@wunner.de>
The removal of the igc module leads to a deadlock:
|[Mon Apr 8 17:38:55 2024] __mutex_lock.constprop.0+0x3e5/0x7a0
|[Mon Apr 8 17:38:55 2024] ? preempt_count_add+0x85/0xd0
|[Mon Apr 8 17:38:55 2024] __mutex_lock_slowpath+0x13/0x20
|[Mon Apr 8 17:38:55 2024] mutex_lock+0x3b/0x50
|[Mon Apr 8 17:38:55 2024] rtnl_lock+0x19/0x20
|[Mon Apr 8 17:38:55 2024] unregister_netdevice_notifier+0x2a/0xc0
|[Mon Apr 8 17:38:55 2024] netdev_trig_deactivate+0x25/0x70
|[Mon Apr 8 17:38:55 2024] led_trigger_set+0xe2/0x2d0
|[Mon Apr 8 17:38:55 2024] led_classdev_unregister+0x4f/0x100
|[Mon Apr 8 17:38:55 2024] devm_led_classdev_release+0x15/0x20
|[Mon Apr 8 17:38:55 2024] release_nodes+0x47/0xc0
|[Mon Apr 8 17:38:55 2024] devres_release_all+0x9f/0xe0
|[Mon Apr 8 17:38:55 2024] device_del+0x272/0x3c0
|[Mon Apr 8 17:38:55 2024] netdev_unregister_kobject+0x8c/0xa0
|[Mon Apr 8 17:38:55 2024] unregister_netdevice_many_notify+0x530/0x7c0
|[Mon Apr 8 17:38:55 2024] unregister_netdevice_queue+0xad/0xf0
|[Mon Apr 8 17:38:55 2024] unregister_netdev+0x21/0x30
|[Mon Apr 8 17:38:55 2024] igc_remove+0xfb/0x1f0 [igc]
|[Mon Apr 8 17:38:55 2024] pci_device_remove+0x42/0xb0
|[Mon Apr 8 17:38:55 2024] device_remove+0x43/0x70
unregister_netdev() acquires the RNTL lock and releases the LEDs bound
to that netdevice. However, netdev_trig_deactivate() and later
unregister_netdevice_notifier() try to acquire the RTNL lock again.
Avoid this situation by not using the device-managed LED class
functions.
Link: https://lore.kernel.org/r/CAEhC_B=ksywxCG_+aQqXUrGEgKq+4mqnSV8EBHOKbC3-Obj9+Q@mail.gmail.com/
Link: https://lore.kernel.org/r/ZhRD3cOtz5i-61PB@mail-itl/
Reported-by: Roman Lozko <lozko.roma@gmail.com>
Reported-by: "Marek Marczykowski-Górecki" <marmarek@invisiblethingslab.com>
Fixes: ea578703b03d ("igc: Add support for LEDs on i225/i226")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
[Kurt: Wrote commit message and tested on i225]
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
---
Changes in v2:
- Add Lukas' SoB (Lukas)
- Add Reported-by (Lukas)
- Add links to discussions
- Take care of error path (Lukas)
- Remove forward declaration (Lukas)
- Link to v1: https://lore.kernel.org/r/20240411-igc_led_deadlock-v1-1-0da98a3c68c5@linutronix.de
---
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 90316dc58630..6bc56c7c181e 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 @@ 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))
diff --git a/drivers/net/ethernet/intel/igc/igc_leds.c b/drivers/net/ethernet/intel/igc/igc_leds.c
index bf240c5daf86..3929b25b6ae6 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 35ad40a803cb..4d975d620a8e 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.
*/
---
base-commit: 7efd0a74039fb6b584be2cb91c1d0ef0bd796ee1
change-id: 20240411-igc_led_deadlock-7abd85954f5e
Best regards,
--
Kurt Kanzenbach <kurt@linutronix.de>
next reply other threads:[~2024-04-15 10:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-15 10:59 Kurt Kanzenbach [this message]
2024-04-16 13:51 ` [Intel-wired-lan] [PATCH iwl-net v2] igc: Fix deadlock on module removal Simon Horman
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