netvsc: need rcu_derefence when accessing internal device info

The netvsc_device structure should be accessed by rcu_dereference
in the send path.  Change arguments to netvsc_send() to make
this easier to do correctly.

Remove no longer needed hv_device_to_netvsc_device.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index e620374..0054b69 100644 (file)
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -183,10 +183,12 @@ struct rndis_device {
 /* Interface */
 struct rndis_message;
 struct netvsc_device;
+struct net_device_context;
+
 struct netvsc_device *netvsc_device_add(struct hv_device *device,
                                        const struct netvsc_device_info *info);
 void netvsc_device_remove(struct hv_device *device);
-int netvsc_send(struct hv_device *device,
+int netvsc_send(struct net_device_context *ndc,
                struct hv_netvsc_packet *packet,
                struct rndis_message *rndis_msg,
                struct hv_page_buffer **page_buffer,
@@ -790,12 +792,6 @@ net_device_to_netvsc_device(struct net_device *ndev)
        return ((struct net_device_context *)netdev_priv(ndev))->nvdev;
 }
 
-static inline struct netvsc_device *
-hv_device_to_netvsc_device(struct hv_device *device)
-{
-       return net_device_to_netvsc_device(hv_get_drvdata(device));
-}
-
 /* NdisInitialize message */
 struct rndis_initialize_request {
        u32 req_id;

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 4a25505..3c6f3ae 100644 (file)
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -822,13 +822,15 @@ static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
        msdp->count = 0;
 }
 
-int netvsc_send(struct hv_device *device,
+/* RCU already held by caller */
+int netvsc_send(struct net_device_context *ndev_ctx,
                struct hv_netvsc_packet *packet,
                struct rndis_message *rndis_msg,
                struct hv_page_buffer **pb,
                struct sk_buff *skb)
 {
-       struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
+       struct netvsc_device *net_device = rcu_dereference(ndev_ctx->nvdev);
+       struct hv_device *device = ndev_ctx->device_ctx;
        int ret = 0;
        struct netvsc_channel *nvchan;
        u32 pktlen = packet->total_data_buflen, msd_len = 0;
@@ -840,7 +842,7 @@ int netvsc_send(struct hv_device *device,
        bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 
        /* If device is rescinded, return error and packet will get dropped. */
-       if (unlikely(net_device->destroy))
+       if (unlikely(!net_device || net_device->destroy))
                return -ENODEV;
 
        /* We may race with netvsc_connect_vsp()/netvsc_init_buf() and get

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 0ca8c74..1238600 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -505,8 +505,8 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 
        /* timestamp packet in software */
        skb_tx_timestamp(skb);
-       ret = netvsc_send(net_device_ctx->device_ctx, packet,
-                         rndis_msg, &pb, skb);
+
+       ret = netvsc_send(net_device_ctx, packet, rndis_msg, &pb, skb);
        if (likely(ret == 0))
                return NETDEV_TX_OK;
 

diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index cacf1e5..9ab67c8 100644 (file)
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -243,7 +243,7 @@ static int rndis_filter_send_request(struct rndis_device *dev,
                        pb[0].len;
        }
 
-       ret = netvsc_send(net_device_ctx->device_ctx, packet, NULL, &pb, NULL);
+       ret = netvsc_send(net_device_ctx, packet, NULL, &pb, NULL);
        return ret;
 }