From 2a926f791211b40ba114f45e0e7bfefd2fac5d30 Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Wed, 19 Jul 2017 11:53:17 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- drivers/net/hyperv/hyperv_net.h | 10 +++------- drivers/net/hyperv/netvsc.c | 8 +++++--- drivers/net/hyperv/netvsc_drv.c | 4 ++-- drivers/net/hyperv/rndis_filter.c | 2 +- 4 files changed, 11 insertions(+), 13 deletions(-) diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h index e620374727c8..0054b6929f6e 100644 --- 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 4a2550559442..3c6f3ae520d9 100644 --- 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 0ca8c74143b4..1238600d717e 100644 --- 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 cacf1e5536f7..9ab67c8309ff 100644 --- 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; } -- 2.20.1