diff options
author | Florian Fainelli <f.fainelli@gmail.com> | 2014-09-08 22:37:52 +0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-09-09 03:02:49 +0400 |
commit | b629be5c8399d7c423b92135eb43a86c924d1cbc (patch) | |
tree | 28483cec84c56b551a51d19a25d5479ea948aae5 /drivers/net/ethernet | |
parent | fe24ba082b8483c81f546d24e40a55624295b85d (diff) | |
download | linux-b629be5c8399d7c423b92135eb43a86c924d1cbc.tar.xz |
net: bcmgenet: 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/genet/bcmgenet.c | 33 |
1 files changed, 19 insertions, 14 deletions
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index 3f9d4de8173c..cdef86a03862 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -1274,12 +1274,29 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv, while ((rxpktprocessed < rxpkttoprocess) && (rxpktprocessed < budget)) { + cb = &priv->rx_cbs[priv->rx_read_ptr]; + skb = cb->skb; + + rxpktprocessed++; + + priv->rx_read_ptr++; + priv->rx_read_ptr &= (priv->num_rx_bds - 1); + + /* We do not have a backing SKB, so we do not have a + * corresponding DMA mapping for this incoming packet since + * bcmgenet_rx_refill always either has both skb and mapping or + * none. + */ + if (unlikely(!skb)) { + dev->stats.rx_dropped++; + dev->stats.rx_errors++; + goto refill; + } + /* Unmap the packet contents such that we can use the * RSV from the 64 bytes descriptor when enabled and save * a 32-bits register read */ - cb = &priv->rx_cbs[priv->rx_read_ptr]; - skb = cb->skb; dma_unmap_single(&dev->dev, dma_unmap_addr(cb, dma_addr), priv->rx_buf_len, DMA_FROM_DEVICE); @@ -1307,18 +1324,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv, __func__, p_index, priv->rx_c_index, priv->rx_read_ptr, dma_length_status); - rxpktprocessed++; - - priv->rx_read_ptr++; - priv->rx_read_ptr &= (priv->num_rx_bds - 1); - - /* out of memory, just drop packets at the hardware level */ - if (unlikely(!skb)) { - dev->stats.rx_dropped++; - dev->stats.rx_errors++; - goto refill; - } - if (unlikely(!(dma_flag & DMA_EOP) || !(dma_flag & DMA_SOP))) { netif_err(priv, rx_status, dev, "dropping fragmented packet!\n"); |