ixgbe: fix panic while dumping packets on Tx hang with IOMMU

This patch resolves a "BUG: unable to handle kernel paging request at ..."
oops while dumping packet data. The issue occurs with IOMMU enabled due to
the address provided by phys_to_virt().

This patch makes use of skb->data on Tx and the virtual address of the pages
allocated for Rx.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 3b6784cf134a..c709eae58c63 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -396,11 +396,10 @@ static void ixgbe_dump(struct ixgbe_adapter *adapter)
                                 pr_cont("\n");
 
                         if (netif_msg_pktdata(adapter) &&
-                            dma_unmap_len(tx_buffer, len) != 0)
+                            tx_buffer->skb)
                                 print_hex_dump(KERN_INFO, "",
                                         DUMP_PREFIX_ADDRESS, 16, 1,
-                                        phys_to_virt(dma_unmap_addr(tx_buffer,
-                                                                    dma)),
+                                        tx_buffer->skb->data,
                                         dma_unmap_len(tx_buffer, len),
                                         true);
                 }
@@ -474,10 +473,12 @@ rx_ring_summary:
                                         (u64)rx_buffer_info->dma,
                                         rx_buffer_info->skb);
 
-                                if (netif_msg_pktdata(adapter)) {
+                                if (netif_msg_pktdata(adapter) &&
+                                    rx_buffer_info->dma) {
                                         print_hex_dump(KERN_INFO, "",
                                            DUMP_PREFIX_ADDRESS, 16, 1,
-                                           phys_to_virt(rx_buffer_info->dma),
+                                           page_address(rx_buffer_info->page) +
+                                                    rx_buffer_info->page_offset,
                                            ixgbe_rx_bufsz(rx_ring), true);
                                 }
                         }