target/linux/leon/patches-2.6.36/021-greth_fix_memory_leak.patch

   1 From 54789a03adf9c924d0cf7b890323c9c1ca7ab042 Mon Sep 17 00:00:00 2001
   2 From: Daniel Hellstrom <daniel@gaisler.com>
   3 Date: Wed, 1 Dec 2010 10:26:09 +0100
   4 Subject: [PATCH] GRETH: fixed skb buffer memory leak on frame errors
   5
   6 A new SKB buffer should not be allocated when the old SKB is reused.
   7
   8 Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
   9 ---
  10  drivers/net/greth.c |   17 +++++++++++------
  11  1 files changed, 11 insertions(+), 6 deletions(-)
  12
  13 --- a/drivers/net/greth.c
  14 +++ b/drivers/net/greth.c
  15 @@ -879,10 +879,8 @@ static int greth_rx_gbit(struct net_devi
  16                         }
  17                 }
  18
  19 -               /* Allocate new skb to replace current */
  20 -               newskb = netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN);
  21 -
  22 -               if (!bad && newskb) {
  23 +               /* Allocate new skb to replace current, not needed if the current skb can be reused */
  24 +               if (!bad && (newskb=netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN))) {
  25                         skb_reserve(newskb, NET_IP_ALIGN);
  26
  27                         dma_addr = dma_map_single(greth->dev,
  28 @@ -919,12 +917,19 @@ static int greth_rx_gbit(struct net_devi
  29                                 if (net_ratelimit())
  30                                         dev_warn(greth->dev, "Could not create DMA mapping, dropping packet\n");
  31                                 dev_kfree_skb(newskb);
  32 -                               dev->stats.rx_dropped++;
  33 +                               dev->stats.rx_dropped++; /* reusing current skb, so it is a drop */
  34                         }
  35 +               } else if ( bad ) {
  36 +                       /* Bad Frame transfer, the skb is reused */
  37 +                       dev->stats.rx_dropped++;
  38                 } else {
  39 +                       /* Failed Allocating a new skb. This is rather stupid but the current "filled"
  40 +                        * skb is reused, as if transfer failure. One could argue that RX descriptor table
  41 +                        * handling should be divided into cleaning and filling as the TX part of the driver
  42 +                        */
  43                         if (net_ratelimit())
  44                                 dev_warn(greth->dev, "Could not allocate SKB, dropping packet\n");
  45 -                       dev->stats.rx_dropped++;
  46 +                       dev->stats.rx_dropped++; /* reusing current skb, so it is a drop */
  47                 }
  48
  49                 status = GRETH_BD_EN | GRETH_BD_IE;