e1000e: Modify Tx/Rx configurations to avoid null pointer dereferences in e1000_open

When e1000e_setup_rx_resources is failed in e1000_open,
e1000e_free_tx_resources in "err_setup_rx" segment is executed.
"writel(0, tx_ring->head)" statement in e1000_clean_tx_ring
in e1000e_free_tx_resources will cause a null poonter dereference(crash),
because "tx_ring->head" is only assigned in e1000_configure_tx
in e1000_configure, but it is after e1000e_setup_rx_resources.

This patch moves head/tail register writing to e1000_configure_tx/rx,
which can fix this problem. It is inspired by igb_configure_tx_ring
in the igb driver.

Specially, thank Alexander Duyck for his valuable suggestion.

Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This commit is contained in:
Jia-Ju Bai 2015-08-05 18:16:10 +08:00 committed by Jeff Kirsher
parent 3eb14ea8d9
commit 0845d45e90

View File

@ -1737,12 +1737,6 @@ static void e1000_clean_rx_ring(struct e1000_ring *rx_ring)
rx_ring->next_to_clean = 0;
rx_ring->next_to_use = 0;
adapter->flags2 &= ~FLAG2_IS_DISCARDING;
writel(0, rx_ring->head);
if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
e1000e_update_rdt_wa(rx_ring, 0);
else
writel(0, rx_ring->tail);
}
static void e1000e_downshift_workaround(struct work_struct *work)
@ -2447,12 +2441,6 @@ static void e1000_clean_tx_ring(struct e1000_ring *tx_ring)
tx_ring->next_to_use = 0;
tx_ring->next_to_clean = 0;
writel(0, tx_ring->head);
if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
e1000e_update_tdt_wa(tx_ring, 0);
else
writel(0, tx_ring->tail);
}
/**
@ -2954,6 +2942,12 @@ static void e1000_configure_tx(struct e1000_adapter *adapter)
tx_ring->head = adapter->hw.hw_addr + E1000_TDH(0);
tx_ring->tail = adapter->hw.hw_addr + E1000_TDT(0);
writel(0, tx_ring->head);
if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
e1000e_update_tdt_wa(tx_ring, 0);
else
writel(0, tx_ring->tail);
/* Set the Tx Interrupt Delay register */
ew32(TIDV, adapter->tx_int_delay);
/* Tx irq moderation */
@ -3275,6 +3269,12 @@ static void e1000_configure_rx(struct e1000_adapter *adapter)
rx_ring->head = adapter->hw.hw_addr + E1000_RDH(0);
rx_ring->tail = adapter->hw.hw_addr + E1000_RDT(0);
writel(0, rx_ring->head);
if (adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
e1000e_update_rdt_wa(rx_ring, 0);
else
writel(0, rx_ring->tail);
/* Enable Receive Checksum Offload for TCP and UDP */
rxcsum = er32(RXCSUM);
if (adapter->netdev->features & NETIF_F_RXCSUM)