From b811ce9104a7f7663ddae4f7795a194a103b8f90 Mon Sep 17 00:00:00 2001
From: Jesse Brandeburg <jesse.brandeburg@intel.com>
Date: Tue, 20 Sep 2011 15:13:03 +0000
Subject: [PATCH] ixgbe: fix possible null buffer error
It seems that at least one PPC machine would occasionally give a (valid) 0 as
the return value from dma_map, this caused the ixgbe code to not work
correctly. A fix is pending in the PPC tree to not return 0 from dma map, but
we can also fix the driver to make sure we don't mess up in other arches as
well.
This patch is applicable to all current stable kernels.
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=683611
Reported-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: stable@kernel.org
Tested-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.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>
---
drivers/net/ixgbe/ixgbe_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 22790394318a..e1fcc9589278 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -1321,8 +1321,8 @@ static void ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
if (ring_is_rsc_enabled(rx_ring))
pkt_is_rsc = ixgbe_get_rsc_state(rx_desc);
- /* if this is a skb from previous receive DMA will be 0 */
- if (rx_buffer_info->dma) {
+ /* linear means we are building an skb from multiple pages */
+ if (!skb_is_nonlinear(skb)) {
u16 hlen;
if (pkt_is_rsc &&
!(staterr & IXGBE_RXD_STAT_EOP) &&
--
2.34.1