@@ -534,6 +534,25 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv,
while ((processed < to_process) && (processed < budget)) {
cb = &priv->rx_cbs[priv->rx_read_ptr];
skb = cb->skb;
+
+ processed++;
+ priv->rx_read_ptr++;
+
+ if (priv->rx_read_ptr == priv->num_rx_bds)
+ priv->rx_read_ptr = 0;
+
+ /* We do not have a backing SKB, so we do not a corresponding
+ * DMA mapping for this incoming packet since
+ * bcm_sysport_rx_refill always either has both skb and mapping
+ * or none.
+ */
+ if (unlikely(!skb)) {
+ netif_err(priv, rx_err, ndev, "out of memory!\n");
+ ndev->stats.rx_dropped++;
+ ndev->stats.rx_errors++;
+ goto refill;
+ }
+
dma_unmap_single(kdev, dma_unmap_addr(cb, dma_addr),
RX_BUF_LENGTH, DMA_FROM_DEVICE);
@@ -543,23 +562,11 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv,
status = (rsb->rx_status_len >> DESC_STATUS_SHIFT) &
DESC_STATUS_MASK;
- processed++;
- priv->rx_read_ptr++;
- if (priv->rx_read_ptr == priv->num_rx_bds)
- priv->rx_read_ptr = 0;
-
netif_dbg(priv, rx_status, ndev,
"p=%d, c=%d, rd_ptr=%d, len=%d, flag=0x%04x\n",
p_index, priv->rx_c_index, priv->rx_read_ptr,
len, status);
- if (unlikely(!skb)) {
- netif_err(priv, rx_err, ndev, "out of memory!\n");
- ndev->stats.rx_dropped++;
- ndev->stats.rx_errors++;
- goto refill;
- }
-
if (unlikely(!(status & DESC_EOP) || !(status & DESC_SOP))) {
netif_err(priv, rx_status, ndev, "fragmented packet!\n");
ndev->stats.rx_dropped++;
There is a potential case where we might be failing to refill a control block, leaving it with both a NULL skb pointer *and* a NULL dma_unmap_addr. The way we process incoming packets, by first calling dma_unmap_single(), and then only checking for a potential NULL skb can lead to situations where do pass a NULL dma_unmap_addr() to dma_unmap_single(), resulting in an oops. Fix this my moving the NULL skb check earlier, since no backing skb also means no corresponding DMA mapping for this packet. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> --- drivers/net/ethernet/broadcom/bcmsysport.c | 31 ++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-)