atl1: fix 4G memory corruption bug

upstream commit: aefdbf1a3b832a580a50cf3d1dcbb717be7cbdbe

When using 4+ GB RAM and SWIOTLB is active, the driver corrupts
memory by writing an skb after the relevant DMA page has been
unmapped.  Although this doesn't happen when *not* using bounce
buffers, clearing the pointer to the DMA page after unmapping
it fixes the problem.

http://marc.info/?t=120861317000005&r=2&w=2

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Jay Cliburn <jacliburn@bellsouth.net>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
[jacliburn@bellsouth.net: backport to 2.6.25.4]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/drivers/net/atl1/atl1_main.c b/drivers/net/atl1/atl1_main.c
index 129b8b3aa7731632853e331ee422435ef419efd3..68be4e1c69aed83a65eb2734eb4eb8d4e6b69f5f 100644 (file)
--- a/drivers/net/atl1/atl1_main.c
+++ b/drivers/net/atl1/atl1_main.c
@@ -1334,6 +1334,7 @@ rrd_ok:
                /* Good Receive */
                pci_unmap_page(adapter->pdev, buffer_info->dma,
                               buffer_info->length, PCI_DMA_FROMDEVICE);
+               buffer_info->dma = 0;
                skb = buffer_info->skb;
                length = le16_to_cpu(rrd->xsz.xsum_sz.pkt_size);