r8169: check dma mapping failures

Check possible dma mapping errors and do clean up if it happens.

Fix overwrap bug in rtl8169_tx_clear on the way.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index 242748b2c357249eb83690ed9bdd634508e31e91..88d5826ce93d43be21f0923b3c43127cbecd097c 100644 (file)
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -3992,11 +3992,18 @@ static struct sk_buff *rtl8169_alloc_rx_data(struct pci_dev *pdev,
                if (!data)
                        return NULL;
        }
+
        mapping = dma_map_single(&pdev->dev, rtl8169_align(data), rx_buf_sz,
                                 PCI_DMA_FROMDEVICE);
+       if (unlikely(dma_mapping_error(&pdev->dev, mapping)))
+               goto err_out;
 
        rtl8169_map_to_asic(desc, mapping, rx_buf_sz);
        return data;
+
+err_out:
+       kfree(data);
+       return NULL;
 }
 
 static void rtl8169_rx_clear(struct rtl8169_private *tp)
@@ -4080,12 +4087,13 @@ static void rtl8169_unmap_tx_skb(struct pci_dev *pdev, struct ring_info *tx_skb,
        tx_skb->len = 0;
 }
 
-static void rtl8169_tx_clear(struct rtl8169_private *tp)
+static void rtl8169_tx_clear_range(struct rtl8169_private *tp, u32 start,
+                                  unsigned int n)
 {
        unsigned int i;
 
-       for (i = tp->dirty_tx; i < tp->dirty_tx + NUM_TX_DESC; i++) {
-               unsigned int entry = i % NUM_TX_DESC;
+       for (i = 0; i < n; i++) {
+               unsigned int entry = (start + i) % NUM_TX_DESC;
                struct ring_info *tx_skb = tp->tx_skb + entry;
                unsigned int len = tx_skb->len;
 
@@ -4101,6 +4109,11 @@ static void rtl8169_tx_clear(struct rtl8169_private *tp)
                        tp->dev->stats.tx_dropped++;
                }
        }
+}
+
+static void rtl8169_tx_clear(struct rtl8169_private *tp)
+{
+       rtl8169_tx_clear_range(tp, tp->dirty_tx, NUM_TX_DESC);
        tp->cur_tx = tp->dirty_tx = 0;
 }
 
@@ -4219,6 +4232,8 @@ static int rtl8169_xmit_frags(struct rtl8169_private *tp, struct sk_buff *skb,
                addr = ((void *) page_address(frag->page)) + frag->page_offset;
                mapping = dma_map_single(&tp->pci_dev->dev, addr, len,
                                         PCI_DMA_TODEVICE);
+               if (unlikely(dma_mapping_error(&tp->pci_dev->dev, mapping)))
+                       goto err_out;
 
                /* anti gcc 2.95.3 bugware (sic) */
                status = opts1 | len | (RingEnd * !((entry + 1) % NUM_TX_DESC));
@@ -4235,6 +4250,10 @@ static int rtl8169_xmit_frags(struct rtl8169_private *tp, struct sk_buff *skb,
        }
 
        return cur_frag;
+
+err_out:
+       rtl8169_tx_clear_range(tp, tp->cur_tx + 1, cur_frag);
+       return -EIO;
 }
 
 static inline u32 rtl8169_tso_csum(struct sk_buff *skb, struct net_device *dev)
@@ -4261,40 +4280,44 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
                                      struct net_device *dev)
 {
        struct rtl8169_private *tp = netdev_priv(dev);
-       unsigned int frags, entry = tp->cur_tx % NUM_TX_DESC;
+       unsigned int entry = tp->cur_tx % NUM_TX_DESC;
        struct TxDesc *txd = tp->TxDescArray + entry;
        void __iomem *ioaddr = tp->mmio_addr;
        dma_addr_t mapping;
        u32 status, len;
        u32 opts1;
+       int frags;
 
        if (unlikely(TX_BUFFS_AVAIL(tp) < skb_shinfo(skb)->nr_frags)) {
                netif_err(tp, drv, dev, "BUG! Tx Ring full when queue awake!\n");
-               goto err_stop;
+               goto err_stop_0;
        }
 
        if (unlikely(le32_to_cpu(txd->opts1) & DescOwn))
-               goto err_stop;
+               goto err_stop_0;
+
+       len = skb_headlen(skb);
+       mapping = dma_map_single(&tp->pci_dev->dev, skb->data, len,
+                                PCI_DMA_TODEVICE);
+       if (unlikely(dma_mapping_error(&tp->pci_dev->dev, mapping)))
+               goto err_dma_0;
+
+       tp->tx_skb[entry].len = len;
+       txd->addr = cpu_to_le64(mapping);
+       txd->opts2 = cpu_to_le32(rtl8169_tx_vlan_tag(tp, skb));
 
        opts1 = DescOwn | rtl8169_tso_csum(skb, dev);
 
        frags = rtl8169_xmit_frags(tp, skb, opts1);
-       if (frags) {
-               len = skb_headlen(skb);
+       if (frags < 0)
+               goto err_dma_1;
+       else if (frags)
                opts1 |= FirstFrag;
-       } else {
-               len = skb->len;
+       else {
                opts1 |= FirstFrag | LastFrag;
                tp->tx_skb[entry].skb = skb;
        }
 
-       mapping = dma_map_single(&tp->pci_dev->dev, skb->data, len,
-                                PCI_DMA_TODEVICE);
-
-       tp->tx_skb[entry].len = len;
-       txd->addr = cpu_to_le64(mapping);
-       txd->opts2 = cpu_to_le32(rtl8169_tx_vlan_tag(tp, skb));
-
        wmb();
 
        /* anti gcc 2.95.3 bugware (sic) */
@@ -4316,7 +4339,14 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
 
        return NETDEV_TX_OK;
 
-err_stop:
+err_dma_1:
+       rtl8169_unmap_tx_skb(tp->pci_dev, tp->tx_skb + entry, txd);
+err_dma_0:
+       dev_kfree_skb(skb);
+       dev->stats.tx_dropped++;
+       return NETDEV_TX_OK;
+
+err_stop_0:
        netif_stop_queue(dev);
        dev->stats.tx_dropped++;
        return NETDEV_TX_BUSY;