e1000e: test for valid check_reset_block function pointer

commit 44abd5c12767a8c567dc4e45fd9aec3b13ca85e0 introduced NULL pointer
dereferences when attempting to access the check_reset_block function
pointer on 8257x and 80003es2lan non-copper devices.

This fix should be applied back through 3.4.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

4 files changed, 12 insertions, 8 deletions

diff --git a/drivers/net/ethernet/intel/e1000e/ethtool.c b/drivers/net/ethernet/intel/e1000e/ethtool.c
index d863075df7a4..905e2147d918 100644
--- a/drivers/net/ethernet/intel/e1000e/ethtool.c
+++ b/drivers/net/ethernet/intel/e1000e/ethtool.c
@@ -258,7 +258,8 @@ static int e1000_set_settings(struct net_device *netdev,
          * When SoL/IDER sessions are active, autoneg/speed/duplex
          * cannot be changed
          */
-        if (hw->phy.ops.check_reset_block(hw)) {
+        if (hw->phy.ops.check_reset_block &&
+            hw->phy.ops.check_reset_block(hw)) {
                 e_err("Cannot change link characteristics when SoL/IDER is active.\n");
                 return -EINVAL;
         }
@@ -1615,7 +1616,8 @@ static int e1000_loopback_test(struct e1000_adapter *adapter, u64 *data)
          * PHY loopback cannot be performed if SoL/IDER
          * sessions are active
          */
-        if (hw->phy.ops.check_reset_block(hw)) {
+        if (hw->phy.ops.check_reset_block &&
+            hw->phy.ops.check_reset_block(hw)) {
                 e_err("Cannot do PHY loopback test when SoL/IDER is active.\n");
                 *data = 0;
                 goto out;
diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c
index 026e8b3ab52e..a13439928488 100644
--- a/drivers/net/ethernet/intel/e1000e/mac.c
+++ b/drivers/net/ethernet/intel/e1000e/mac.c
@@ -709,7 +709,7 @@ s32 e1000e_setup_link_generic(struct e1000_hw *hw)
          * In the case of the phy reset being blocked, we already have a link.
          * We do not need to set it up again.
          */
-        if (hw->phy.ops.check_reset_block(hw))
+        if (hw->phy.ops.check_reset_block && hw->phy.ops.check_reset_block(hw))
                 return 0;
 
         /*
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index a4b0435b00dc..31d37a2b5ba8 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -6237,7 +6237,7 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
                 adapter->hw.phy.ms_type = e1000_ms_hw_default;
         }
 
-        if (hw->phy.ops.check_reset_block(hw))
+        if (hw->phy.ops.check_reset_block && hw->phy.ops.check_reset_block(hw))
                 e_info("PHY reset is blocked due to SOL/IDER session.\n");
 
         /* Set initial default active device features */
@@ -6404,7 +6404,7 @@ err_register:
         if (!(adapter->flags & FLAG_HAS_AMT))
                 e1000e_release_hw_control(adapter);
 err_eeprom:
-        if (!hw->phy.ops.check_reset_block(hw))
+        if (hw->phy.ops.check_reset_block && !hw->phy.ops.check_reset_block(hw))
                 e1000_phy_hw_reset(&adapter->hw);
 err_hw_init:
         kfree(adapter->tx_ring);
diff --git a/drivers/net/ethernet/intel/e1000e/phy.c b/drivers/net/ethernet/intel/e1000e/phy.c
index 0334d013bc3c..b860d4f7ea2a 100644
--- a/drivers/net/ethernet/intel/e1000e/phy.c
+++ b/drivers/net/ethernet/intel/e1000e/phy.c
@@ -2155,9 +2155,11 @@ s32 e1000e_phy_hw_reset_generic(struct e1000_hw *hw)
         s32 ret_val;
         u32 ctrl;
 
-        ret_val = phy->ops.check_reset_block(hw);
-        if (ret_val)
-                return 0;
+        if (phy->ops.check_reset_block) {
+                ret_val = phy->ops.check_reset_block(hw);
+                if (ret_val)
+                        return 0;
+        }
 
         ret_val = phy->ops.acquire(hw);
         if (ret_val)