Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754662Ab2JNOnD (ORCPT ); Sun, 14 Oct 2012 10:43:03 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46384 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754515Ab2JNOm7 (ORCPT ); Sun, 14 Oct 2012 10:42:59 -0400 Message-Id: <20121014143548.230457808@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 14 Oct 2012 15:37:20 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Alexandre Bounine , Matt Porter , "David S. Miller" , Linus Torvalds Subject: [ 107/147] rapidio/rionet: fix multicast packet transmit logic In-Reply-To: <20121014143533.742627615@decadent.org.uk> X-SA-Exim-Connect-IP: 77.75.106.1 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3754 Lines: 110 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Bounine commit 7c4a6106d6451fc03c491e61df37c044505d843a upstream. Fix multicast packet transmit logic to account for repetitive transmission of single skb: - correct check for available buffers (this bug may produce NULL pointer crash dump in case of heavy traffic); - update skb user count (incorrect user counter causes a warning dump from net_tx_action routine during multicast transfers in systems with three or more rionet participants). Signed-off-by: Alexandre Bounine Cc: Matt Porter Cc: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- drivers/net/rionet.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/net/rionet.c b/drivers/net/rionet.c index 91d2588..1470d3e 100644 --- a/drivers/net/rionet.c +++ b/drivers/net/rionet.c @@ -79,6 +79,7 @@ static int rionet_capable = 1; * on system trade-offs. */ static struct rio_dev **rionet_active; +static int nact; /* total number of active rionet peers */ #define is_rionet_capable(src_ops, dst_ops) \ ((src_ops & RIO_SRC_OPS_DATA_MSG) && \ @@ -175,6 +176,7 @@ static int rionet_start_xmit(struct sk_buff *skb, struct net_device *ndev) struct ethhdr *eth = (struct ethhdr *)skb->data; u16 destid; unsigned long flags; + int add_num = 1; local_irq_save(flags); if (!spin_trylock(&rnet->tx_lock)) { @@ -182,7 +184,10 @@ static int rionet_start_xmit(struct sk_buff *skb, struct net_device *ndev) return NETDEV_TX_LOCKED; } - if ((rnet->tx_cnt + 1) > RIONET_TX_RING_SIZE) { + if (is_multicast_ether_addr(eth->h_dest)) + add_num = nact; + + if ((rnet->tx_cnt + add_num) > RIONET_TX_RING_SIZE) { netif_stop_queue(ndev); spin_unlock_irqrestore(&rnet->tx_lock, flags); printk(KERN_ERR "%s: BUG! Tx Ring full when queue awake!\n", @@ -191,11 +196,16 @@ static int rionet_start_xmit(struct sk_buff *skb, struct net_device *ndev) } if (is_multicast_ether_addr(eth->h_dest)) { + int count = 0; for (i = 0; i < RIO_MAX_ROUTE_ENTRIES(rnet->mport->sys_size); i++) - if (rionet_active[i]) + if (rionet_active[i]) { rionet_queue_tx_msg(skb, ndev, rionet_active[i]); + if (count) + atomic_inc(&skb->users); + count++; + } } else if (RIONET_MAC_MATCH(eth->h_dest)) { destid = RIONET_GET_DESTID(eth->h_dest); if (rionet_active[destid]) @@ -220,14 +230,17 @@ static void rionet_dbell_event(struct rio_mport *mport, void *dev_id, u16 sid, u if (info == RIONET_DOORBELL_JOIN) { if (!rionet_active[sid]) { list_for_each_entry(peer, &rionet_peers, node) { - if (peer->rdev->destid == sid) + if (peer->rdev->destid == sid) { rionet_active[sid] = peer->rdev; + nact++; + } } rio_mport_send_doorbell(mport, sid, RIONET_DOORBELL_JOIN); } } else if (info == RIONET_DOORBELL_LEAVE) { rionet_active[sid] = NULL; + nact--; } else { if (netif_msg_intr(rnet)) printk(KERN_WARNING "%s: unhandled doorbell\n", @@ -523,6 +536,7 @@ static int rionet_probe(struct rio_dev *rdev, const struct rio_device_id *id) rc = rionet_setup_netdev(rdev->net->hport, ndev); rionet_check = 1; + nact = 0; } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/