diff mbox series

ibmvnic: Do not process device remove during device reset

Message ID 20200310000058.58521-1-julietk@linux.vnet.ibm.com (mailing list archive)
State Not Applicable
Headers show
Series ibmvnic: Do not process device remove during device reset | expand

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Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (ab326587bb5fb91cc97df9b9f48e9e1469f04621)
snowpatch_ozlabs/build-ppc64le success Build succeeded
snowpatch_ozlabs/build-ppc64be success Build succeeded
snowpatch_ozlabs/build-ppc64e success Build succeeded
snowpatch_ozlabs/build-pmac32 success Build succeeded
snowpatch_ozlabs/checkpatch success total: 0 errors, 0 warnings, 0 checks, 77 lines checked
snowpatch_ozlabs/needsstable success Patch has no Fixes tags

Commit Message

Juliet Kim March 10, 2020, midnight UTC
The ibmvnic driver does not check the device state when the device
is removed. If the device is removed while a device reset is being 
processed, the remove may free structures needed by the reset, 
causing an oops.

Fix this by checking the device state before processing device remove.

Signed-off-by: Juliet Kim <julietk@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 24 ++++++++++++++++++++++--
 drivers/net/ethernet/ibm/ibmvnic.h |  6 +++++-
 2 files changed, 27 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index c75239d8820f..7ef1ae0d49bc 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -2144,6 +2144,8 @@  static void __ibmvnic_reset(struct work_struct *work)
 	struct ibmvnic_adapter *adapter;
 	u32 reset_state;
 	int rc = 0;
+	unsigned long flags;
+	bool saved_state = false;
 
 	adapter = container_of(work, struct ibmvnic_adapter, ibmvnic_reset);
 
@@ -2153,17 +2155,25 @@  static void __ibmvnic_reset(struct work_struct *work)
 		return;
 	}
 
-	reset_state = adapter->state;
-
 	rwi = get_next_rwi(adapter);
 	while (rwi) {
+		spin_lock_irqsave(&adapter->state_lock, flags);
+
 		if (adapter->state == VNIC_REMOVING ||
 		    adapter->state == VNIC_REMOVED) {
+			spin_unlock_irqrestore(&adapter->state_lock, flags);
 			kfree(rwi);
 			rc = EBUSY;
 			break;
 		}
 
+		if (!saved_state) {
+			reset_state = adapter->state;
+			adapter->state = VNIC_RESETTING;
+			saved_state = true;
+		}
+		spin_unlock_irqrestore(&adapter->state_lock, flags);
+
 		if (rwi->reset_reason == VNIC_RESET_CHANGE_PARAM) {
 			/* CHANGE_PARAM requestor holds rtnl_lock */
 			rc = do_change_param_reset(adapter, rwi, reset_state);
@@ -5091,6 +5101,7 @@  static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 			  __ibmvnic_delayed_reset);
 	INIT_LIST_HEAD(&adapter->rwi_list);
 	spin_lock_init(&adapter->rwi_lock);
+	spin_lock_init(&adapter->state_lock);
 	mutex_init(&adapter->fw_lock);
 	init_completion(&adapter->init_done);
 	init_completion(&adapter->fw_done);
@@ -5161,10 +5172,19 @@  static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 
 static int ibmvnic_remove(struct vio_dev *dev)
 {
+	unsigned long flags;
 	struct net_device *netdev = dev_get_drvdata(&dev->dev);
 	struct ibmvnic_adapter *adapter = netdev_priv(netdev);
 
+	spin_lock_irqsave(&adapter->state_lock, flags);
+	if (adapter->state == VNIC_RESETTING) {
+		spin_unlock_irqrestore(&adapter->state_lock, flags);
+		return -EBUSY;
+	}
+
 	adapter->state = VNIC_REMOVING;
+	spin_unlock_irqrestore(&adapter->state_lock, flags);
+
 	rtnl_lock();
 	unregister_netdevice(netdev);
 
diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h
index 60eccaf91b12..971505e4cc52 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.h
+++ b/drivers/net/ethernet/ibm/ibmvnic.h
@@ -941,7 +941,8 @@  enum vnic_state {VNIC_PROBING = 1,
 		 VNIC_CLOSING,
 		 VNIC_CLOSED,
 		 VNIC_REMOVING,
-		 VNIC_REMOVED};
+		 VNIC_REMOVED,
+		 VNIC_RESETTING};
 
 enum ibmvnic_reset_reason {VNIC_RESET_FAILOVER = 1,
 			   VNIC_RESET_MOBILITY,
@@ -1090,4 +1091,7 @@  struct ibmvnic_adapter {
 
 	struct ibmvnic_tunables desired;
 	struct ibmvnic_tunables fallback;
+
+	/* lock to protect state field */
+	spinlock_t state_lock;
 };