This is a note to let you know that I've just added the patch titled
virtio-net: correct error handling of virtqueue_kick()
to the 3.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
virtio-net-correct-error-handling-of-virtqueue_kick.patch
and it can be found in the queue-3.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From foo@baz Thu Apr 10 22:03:04 PDT 2014
From: Jason Wang <[email protected]>
Date: Wed, 26 Mar 2014 13:03:00 +0800
Subject: virtio-net: correct error handling of virtqueue_kick()
From: Jason Wang <[email protected]>
[ Upstream commit 681daee2443291419c57cccb0671f5f94a839005 ]
Current error handling of virtqueue_kick() was wrong in two places:
- The skb were freed immediately when virtqueue_kick() fail during
xmit. This may lead double free since the skb was not detached from
the virtqueue.
- try_fill_recv() returns false when virtqueue_kick() fail. This will
lead unnecessary rescheduling of refill work.
Actually, it's safe to just ignore the kick failure in those two
places. So this patch fixes this by partially revert commit
67975901183799af8e93ec60e322f9e2a1940b9b.
Fixes 67975901183799af8e93ec60e322f9e2a1940b9b
(virtio_net: verify if virtqueue_kick() succeeded).
Cc: Heinz Graalfs <[email protected]>
Cc: Rusty Russell <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Signed-off-by: Jason Wang <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/net/virtio_net.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -633,8 +633,7 @@ static bool try_fill_recv(struct receive
} while (rq->vq->num_free);
if (unlikely(rq->num > rq->max))
rq->max = rq->num;
- if (unlikely(!virtqueue_kick(rq->vq)))
- return false;
+ virtqueue_kick(rq->vq);
return !oom;
}
@@ -840,7 +839,7 @@ static netdev_tx_t start_xmit(struct sk_
err = xmit_skb(sq, skb);
/* This should not happen! */
- if (unlikely(err) || unlikely(!virtqueue_kick(sq->vq))) {
+ if (unlikely(err)) {
dev->stats.tx_fifo_errors++;
if (net_ratelimit())
dev_warn(&dev->dev,
@@ -849,6 +848,7 @@ static netdev_tx_t start_xmit(struct sk_
kfree_skb(skb);
return NETDEV_TX_OK;
}
+ virtqueue_kick(sq->vq);
/* Don't wait up for transmitted skbs to be freed. */
skb_orphan(skb);
Patches currently in stable-queue which might be from [email protected] are
queue-3.13/virtio-net-correct-error-handling-of-virtqueue_kick.patch
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