net: mvneta: fix DMA buffer unmapping in mvneta_rx()

This patch fixes a regression introduced by the commit a84e32894191
("net: mvneta: fix refilling for Rx DMA buffers"). Due to this commit
the newly allocated Rx buffers are DMA-unmapped in place of those passed
to the networking stack. Obviously, this causes data corruptions.

This patch fixes the issue by ensuring that the right Rx buffers are
DMA-unmapped.

Reported-by: Oren Laskin <oren@igneous.io>
Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Fixes: a84e32894191 ("net: mvneta: fix refilling for Rx DMA buffers")
Cc: <stable@vger.kernel.org> # v3.8+
Tested-by: Oren Laskin <oren@igneous.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index fe2299ac4f5c0e43b1ff3cf124381df3a1daecf1..09ec32e33076cf84040be77006b0607b4806f8eb 100644 (file)
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -1479,6 +1479,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
                struct mvneta_rx_desc *rx_desc = mvneta_rxq_next_desc_get(rxq);
                struct sk_buff *skb;
                unsigned char *data;
+               dma_addr_t phys_addr;
                u32 rx_status;
                int rx_bytes, err;
 
@@ -1486,6 +1487,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
                rx_status = rx_desc->status;
                rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE);
                data = (unsigned char *)rx_desc->buf_cookie;
+               phys_addr = rx_desc->buf_phys_addr;
 
                if (!mvneta_rxq_desc_is_first_last(rx_status) ||
                    (rx_status & MVNETA_RXD_ERR_SUMMARY)) {
@@ -1534,7 +1536,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
                if (!skb)
                        goto err_drop_frame;
 
-               dma_unmap_single(dev->dev.parent, rx_desc->buf_phys_addr,
+               dma_unmap_single(dev->dev.parent, phys_addr,
                                 MVNETA_RX_BUF_SIZE(pp->pkt_size), DMA_FROM_DEVICE);
 
                rcvd_pkts++;