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