From: =?UTF-8?q?Pawe=C5=82=20Jab=C5=82o=C5=84ski?=
Date: Mon, 5 Feb 2018 13:03:36 -0800
 <pawel.jablonski@intel.com>
Subject: i40evf: Fix double locking the same resource
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Patch-mainline: v4.17-rc1
Git-commit: 8cd5fe62cc5a2aca1c698c28baa46ac6931ba11f
References: bsc#1101816 FATE#325147 FATE#325149

Removes the locking of adapter->mac_vlan_list_lock resource in
i40evf_add_filter(). The locking part is moved above i40evf_add_filter().
i40evf_add_filter(), called by i40evf_addr_sync(), was trying to lock the
resource again and double locking generated a kernel panic after bringing
an interface up.

Fixes: 8946b56354b7 ("i40evf: use __dev_[um]c_sync routines in
       .set_rx_mode")
Signed-off-by: Paweł Jabłoński <pawel.jablonski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/i40evf/i40evf_main.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -815,13 +815,11 @@ i40evf_mac_filter *i40evf_add_filter(str
 	if (!macaddr)
 		return NULL;
 
-	spin_lock_bh(&adapter->mac_vlan_list_lock);
-
 	f = i40evf_find_filter(adapter, macaddr);
 	if (!f) {
 		f = kzalloc(sizeof(*f), GFP_ATOMIC);
 		if (!f)
-			goto clearout;
+			return f;
 
 		ether_addr_copy(f->macaddr, macaddr);
 
@@ -832,8 +830,6 @@ i40evf_mac_filter *i40evf_add_filter(str
 		f->remove = false;
 	}
 
-clearout:
-	spin_unlock_bh(&adapter->mac_vlan_list_lock);
 	return f;
 }
 
@@ -868,9 +864,10 @@ static int i40evf_set_mac(struct net_dev
 		adapter->aq_required |= I40EVF_FLAG_AQ_DEL_MAC_FILTER;
 	}
 
+	f = i40evf_add_filter(adapter, addr->sa_data);
+
 	spin_unlock_bh(&adapter->mac_vlan_list_lock);
 
-	f = i40evf_add_filter(adapter, addr->sa_data);
 	if (f) {
 		ether_addr_copy(hw->mac.addr, addr->sa_data);
 		ether_addr_copy(netdev->dev_addr, adapter->hw.mac.addr);
@@ -2256,7 +2253,12 @@ static int i40evf_open(struct net_device
 	if (err)
 		goto err_req_irq;
 
+	spin_lock_bh(&adapter->mac_vlan_list_lock);
+
 	i40evf_add_filter(adapter, adapter->hw.mac.addr);
+
+	spin_unlock_bh(&adapter->mac_vlan_list_lock);
+
 	i40evf_configure(adapter);
 
 	i40evf_up_complete(adapter);