From 225686544fb9af569ea70a46e11fe130c6da5bd2 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Thu, 16 Jun 2011 13:16:37 -0700 Subject: [PATCH] Staging: hv: netvsc: Fix a bug in accounting transmit slots [ upstream commit 9079ce691255792009c446d8c3382507b8d38635 ] The transmit slots were manipulated without proper locking. Fix this bug by making the variable tracking the transmit slots atomic. This patch should be ported to prior stable kernels 2.6.32 and later. Signed-off-by: K. Y. Srinivasan Signed-off-by: Haiyang Zhang Signed-off-by: Hank Janssen Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- drivers/staging/hv/netvsc_drv.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/staging/hv/netvsc_drv.c b/drivers/staging/hv/netvsc_drv.c index f1a7402f5d5b7..0ad89cca375ad 100644 --- a/drivers/staging/hv/netvsc_drv.c +++ b/drivers/staging/hv/netvsc_drv.c @@ -19,6 +19,7 @@ * Hank Janssen */ #include +#include #include #include #include @@ -45,7 +46,7 @@ struct net_device_context { /* point back to our device context */ struct vm_device *device_ctx; - unsigned long avail; + atomic_t avail; struct work_struct work; }; @@ -133,7 +134,9 @@ static void netvsc_xmit_completion(void *context) dev_kfree_skb_any(skb); - if ((net_device_ctx->avail += num_pages) >= PACKET_PAGES_HIWATER) + atomic_add(num_pages, &net_device_ctx->avail); + if (atomic_read(&net_device_ctx->avail) >= + PACKET_PAGES_HIWATER) netif_wake_queue(net); } @@ -159,7 +162,7 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) /* Add 1 for skb->data and additional one for RNDIS */ num_pages = skb_shinfo(skb)->nr_frags + 1 + 1; - if (num_pages > net_device_ctx->avail) + if (num_pages > atomic_read(&net_device_ctx->avail)) return NETDEV_TX_BUSY; /* Allocate a netvsc packet based on # of frags. */ @@ -218,7 +221,8 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) net->stats.tx_packets, net->stats.tx_bytes); - if ((net_device_ctx->avail -= num_pages) < PACKET_PAGES_LOWATER) + atomic_sub(num_pages, &net_device_ctx->avail); + if (atomic_read(&net_device_ctx->avail) < PACKET_PAGES_LOWATER) netif_stop_queue(net); } else { /* we are shutting down or bus overloaded, just drop packet */ @@ -406,7 +410,7 @@ static int netvsc_probe(struct device *device) net_device_ctx = netdev_priv(net); net_device_ctx->device_ctx = device_ctx; - net_device_ctx->avail = ring_size; + atomic_set(&net_device_ctx->avail, ring_size); dev_set_drvdata(device, net); INIT_WORK(&net_device_ctx->work, netvsc_send_garp); -- 2.47.2