From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [PATCH PATCH net v2 3/4] hv_netvsc: fix locking for rx_mode Date: Wed, 7 Mar 2018 13:49:11 -0800 Message-ID: <20180307214912.5470-4-sthemmin@microsoft.com> References: <20180307214912.5470-1-sthemmin@microsoft.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: devel@linuxdriverproject.org, netdev@vger.kernel.org To: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com Return-path: In-Reply-To: <20180307214912.5470-1-sthemmin@microsoft.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" List-Id: netdev.vger.kernel.org The rx_mode operation handler is different than other callbacks in that is not always called with rtnl held. Therefore use RCU to ensure that references are valid. Fixes: bee9d41b37ea ("hv_netvsc: propagate rx filters to VF") Signed-off-by: Stephen Hemminger --- drivers/net/hyperv/netvsc_drv.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index cdb78eefab67..48d9fa7a66c2 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -89,15 +89,20 @@ static void netvsc_change_rx_flags(struct net_device *net, int change) static void netvsc_set_rx_mode(struct net_device *net) { struct net_device_context *ndev_ctx = netdev_priv(net); - struct net_device *vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev); - struct netvsc_device *nvdev = rtnl_dereference(ndev_ctx->nvdev); + struct net_device *vf_netdev; + struct netvsc_device *nvdev; + rcu_read_lock(); + vf_netdev = rcu_dereference(ndev_ctx->vf_netdev); if (vf_netdev) { dev_uc_sync(vf_netdev, net); dev_mc_sync(vf_netdev, net); } - rndis_filter_update(nvdev); + nvdev = rcu_dereference(ndev_ctx->nvdev); + if (nvdev) + rndis_filter_update(nvdev); + rcu_read_unlock(); } static int netvsc_open(struct net_device *net) -- 2.16.1