fm10k: prevent RCU issues during AER events

During an AER action response, we were calling fm10k_close without
holding the rtnl_lock() which could lead to possible RCU warnings being
produced due to 64bit stat updates among other causes. Similarly, we
need rtnl_lock() around fm10k_open during fm10k_io_resume. Follow the
same pattern elsewhere in the driver and protect the entire open/close
sequence.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c
index f099295..a604513 100644 (file)
--- a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c
@@ -2271,6 +2271,8 @@ static pci_ers_result_t fm10k_io_error_detected(struct pci_dev *pdev,
        if (state == pci_channel_io_perm_failure)
                return PCI_ERS_RESULT_DISCONNECT;
 
+       rtnl_lock();
+
        if (netif_running(netdev))
                fm10k_close(netdev);
 
@@ -2279,6 +2281,8 @@ static pci_ers_result_t fm10k_io_error_detected(struct pci_dev *pdev,
        /* free interrupts */
        fm10k_clear_queueing_scheme(interface);
 
+       rtnl_unlock();
+
        pci_disable_device(pdev);
 
        /* Request a slot reset. */
@@ -2349,11 +2353,13 @@ static void fm10k_io_resume(struct pci_dev *pdev)
        /* reset statistics starting values */
        hw->mac.ops.rebind_hw_stats(hw, &interface->stats);
 
+       rtnl_lock();
+
        err = fm10k_init_queueing_scheme(interface);
        if (err) {
                dev_err(&interface->pdev->dev,
                        "init_queueing_scheme failed: %d\n", err);
-               return;
+               goto unlock;
        }
 
        /* reassociate interrupts */
@@ -2370,6 +2376,9 @@ static void fm10k_io_resume(struct pci_dev *pdev)
 
        if (!err)
                netif_device_attach(netdev);
+
+unlock:
+       rtnl_unlock();
 }
 
 static const struct pci_error_handlers fm10k_err_handler = {