Commit cd0ea241 authored Oct 19, 2010 by Jarek Poplawski Committed by David S. Miller Oct 27, 2010

gianfar: Fix crashes on RX path (Was Re: [Bugme-new] [Bug 19692] New:...


gianfar: Fix crashes on RX path (Was Re: [Bugme-new] [Bug 19692] New: linux-2.6.36-rc5 crash with gianfar ethernet at full line rate traffic)

The rx_recycle queue is global per device but can be accesed by many
napi handlers at the same time, so it needs full skb_queue primitives
(with locking). Otherwise, various crashes caused by broken skbs are
possible.

This patch resolves, at least partly, bugzilla bug 19692. (Because of
some doubts that there could be still something around which is hard
to reproduce my proposal is to leave this bug opened for a month.)

Fixes commit: 0fd56bb5 ("gianfar: Add
support for skb recycling")

Reported-by: emin ak <eminak71@gmail.com>
Tested-by: emin ak <eminak71@gmail.com>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
CC: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 7a876b0e

drivers/net/gianfar.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -2511,7 +2511,7 @@ static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
		skb_recycle_check(skb, priv->rx_buffer_size +
		RXBUF_ALIGNMENT)) {
		gfar_align_skb(skb);
		__skb_queue_head(&priv->rx_recycle, skb);
		skb_queue_head(&priv->rx_recycle, skb);
		} else
		dev_kfree_skb_any(skb);

		@@ -2594,7 +2594,7 @@ struct sk_buff * gfar_new_skb(struct net_device *dev)
		struct gfar_private *priv = netdev_priv(dev);
		struct sk_buff *skb = NULL;

		skb = __skb_dequeue(&priv->rx_recycle);
		skb = skb_dequeue(&priv->rx_recycle);
		if (!skb)
		skb = gfar_alloc_skb(dev);

		@@ -2750,7 +2750,7 @@ int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue, int rx_work_limit)
		if (unlikely(!newskb))
		newskb = skb;
		else if (skb)
		__skb_queue_head(&priv->rx_recycle, skb);
		skb_queue_head(&priv->rx_recycle, skb);
		} else {
		/* Increment the number of packets */
		rx_queue->stats.rx_packets++;

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