From 0579fafd37fb7efe091f0e6c8ccf968864f40f3e Mon Sep 17 00:00:00 2001 From: Slawomir Laba Date: Wed, 23 Feb 2022 13:37:50 +0100 Subject: iavf: Fix locking for VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS iavf_virtchnl_completion is called under crit_lock but when the code for VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS is called, this lock is released in order to obtain rtnl_lock to avoid ABBA deadlock with unregister_netdev. Along with the new way iavf_remove behaves, there exist many risks related to the lock release and attmepts to regrab it. The driver faces crashes related to races between unregister_netdev and netdev_update_features. Yet another risk is that the driver could already obtain the crit_lock in order to destroy it and iavf_virtchnl_completion could crash or block forever. Make iavf_virtchnl_completion never relock crit_lock in it's call paths. Extract rtnl_lock locking logic to the driver for unregister_netdev in order to set the netdev_registered flag inside the lock. Introduce a new flag that will inform adminq_task to perform the code from VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2_CAPS right after it finishes processing messages. Guard this code with remove flags so it's never called when the driver is in remove state. Fixes: 5951a2b9812d ("iavf: Fix VLAN feature flags after VFR") Signed-off-by: Slawomir Laba Signed-off-by: Phani Burra Signed-off-by: Jacob Keller Signed-off-by: Mateusz Palczewski Tested-by: Konrad Jankowski Signed-off-by: Tony Nguyen --- drivers/net/ethernet/intel/iavf/iavf_virtchnl.c | 24 +----------------------- 1 file changed, 1 insertion(+), 23 deletions(-) (limited to 'drivers/net/ethernet/intel/iavf/iavf_virtchnl.c') diff --git a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c index 5ee1d118fd30..88844d68e150 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c +++ b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c @@ -2146,29 +2146,7 @@ void iavf_virtchnl_completion(struct iavf_adapter *adapter, sizeof(adapter->vlan_v2_caps))); iavf_process_config(adapter); - - /* unlock crit_lock before acquiring rtnl_lock as other - * processes holding rtnl_lock could be waiting for the same - * crit_lock - */ - mutex_unlock(&adapter->crit_lock); - /* VLAN capabilities can change during VFR, so make sure to - * update the netdev features with the new capabilities - */ - rtnl_lock(); - netdev_update_features(netdev); - rtnl_unlock(); - if (iavf_lock_timeout(&adapter->crit_lock, 10000)) - dev_warn(&adapter->pdev->dev, "failed to acquire crit_lock in %s\n", - __FUNCTION__); - - /* Request VLAN offload settings */ - if (VLAN_V2_ALLOWED(adapter)) - iavf_set_vlan_offload_features(adapter, 0, - netdev->features); - - iavf_set_queue_vlan_tag_loc(adapter); - + adapter->flags |= IAVF_FLAG_SETUP_NETDEV_FEATURES; } break; case VIRTCHNL_OP_ENABLE_QUEUES: -- cgit v1.2.3