i40e: prevent null pointer exception in dump descriptor

Check that rings were allocated before trying to reference them.

Change-Id: I33151e55ab7a7a305fecdb88ccb2709ac246b7c7
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
index 18296f8fcb6846a546eac715db0ebeb60e2f86df..0ce0664de2eac741a25894a30dde4d06d3e1a991 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
@@ -782,6 +782,12 @@ static void i40e_dbg_dump_desc(int cnt, int vsi_seid, int ring_id, int desc_n,
                        dev_info(&pf->pdev->dev, "dump desc tx <vsi_seid> <ring_id> [<desc_n>]\n");
                return;
        }
+       if (!vsi->tx_rings) {
+               dev_info(&pf->pdev->dev,
+                        "descriptor rings have not been allocated for vsi %d\n",
+                        vsi_seid);
+               return;
+       }
        if (is_rx_ring)
                ring = *vsi->rx_rings[ring_id];
        else