diff options
author | Florian Fainelli <f.fainelli@gmail.com> | 2014-09-08 22:37:51 +0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-09-09 03:02:49 +0400 |
commit | fe24ba082b8483c81f546d24e40a55624295b85d (patch) | |
tree | 8beda3a9ad3031dac7a4d85e07950e3b9df8fc9a /drivers/net/ethernet | |
parent | 278d436a476f69fc95d5c82bf61b6c2d02f4d44e (diff) | |
download | linux-fe24ba082b8483c81f546d24e40a55624295b85d.tar.xz |
net: systemport: check harder for out of memory conditions
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet')
-rw-r--r-- | drivers/net/ethernet/broadcom/bcmsysport.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index 6f4e18644bd4..d9b9170ed2fc 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -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++; |