tg3: Avoid null pointer dereference in tg3_interrupt in netconsole mode

When netconsole is enabled, logging messages generated during tg3_open
can result in a null pointer dereference for the uninitialized tg3
status block. Use the irq_sync flag to disable polling in the early
stages. irq_sync is cleared when the driver is enabling interrupts after
all initialization is completed.

Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 78ea90c40e19..d326d9219aa8 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -6950,6 +6950,9 @@ static void tg3_poll_controller(struct net_device *dev)
         int i;
         struct tg3 *tp = netdev_priv(dev);
 
+        if (tg3_irq_sync(tp))
+                return;
+
         for (i = 0; i < tp->irq_cnt; i++)
                 tg3_interrupt(tp->napi[i].irq_vec, &tp->napi[i]);
 }
@@ -16367,6 +16370,7 @@ static int tg3_init_one(struct pci_dev *pdev,
         tp->pm_cap = pm_cap;
         tp->rx_mode = TG3_DEF_RX_MODE;
         tp->tx_mode = TG3_DEF_TX_MODE;
+        tp->irq_sync = 1;
 
         if (tg3_debug > 0)
                 tp->msg_enable = tg3_debug;