net: fec: fix missing kmalloc() failure check in fec_enet_alloc_buffers()

fec_enet_alloc_buffers() assumes that kmalloc() will never fail, which
is an invalid assumption.  Fix this by implementing a common error
cleanup path, and use it to also clean up after failed bounce buffer
allocation.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 5499bd8ad0a5..f43c388e2eb9 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2100,19 +2100,16 @@ static int fec_enet_alloc_buffers(struct net_device *ndev)
                 dma_addr_t addr;
 
                 skb = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);
-                if (!skb) {
-                        fec_enet_free_buffers(ndev);
-                        return -ENOMEM;
-                }
+                if (!skb)
+                        goto err_alloc;
 
                 addr = dma_map_single(&fep->pdev->dev, skb->data,
                                 FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);
                 if (dma_mapping_error(&fep->pdev->dev, addr)) {
                         dev_kfree_skb(skb);
-                        fec_enet_free_buffers(ndev);
                         if (net_ratelimit())
                                 netdev_err(ndev, "Rx DMA memory map failed\n");
-                        return -ENOMEM;
+                        goto err_alloc;
                 }
 
                 fep->rx_skbuff[i] = skb;
@@ -2134,6 +2131,8 @@ static int fec_enet_alloc_buffers(struct net_device *ndev)
         bdp = fep->tx_bd_base;
         for (i = 0; i < fep->tx_ring_size; i++) {
                 fep->tx_bounce[i] = kmalloc(FEC_ENET_TX_FRSIZE, GFP_KERNEL);
+                if (!fep->tx_bounce[i])
+                        goto err_alloc;
 
                 bdp->cbd_sc = 0;
                 bdp->cbd_bufaddr = 0;
@@ -2151,6 +2150,10 @@ static int fec_enet_alloc_buffers(struct net_device *ndev)
         bdp->cbd_sc |= BD_SC_WRAP;
 
         return 0;
+
+ err_alloc:
+        fec_enet_free_buffers(ndev);
+        return -ENOMEM;
 }
 
 static int