From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:48825 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753778AbbH0WMy (ORCPT ); Thu, 27 Aug 2015 18:12:54 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Mahesh Bandewar , Cong Wang , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 065/130] ipvlan: use rcu_deference_bh() in ipvlan_queue_xmit() Date: Thu, 27 Aug 2015 15:10:56 -0700 Message-Id: <1440713521-5906-66-git-send-email-kamal@canonical.com> In-Reply-To: <1440713521-5906-1-git-send-email-kamal@canonical.com> References: <1440713521-5906-1-git-send-email-kamal@canonical.com> Sender: stable-owner@vger.kernel.org List-ID: 3.19.8-ckt6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: WANG Cong commit 0fba37a3af03a7e74bf9e75473729adb98da49c3 upstream. In tx path rcu_read_lock_bh() is held, so we need rcu_deference_bh(). This fixes the following warning: =============================== [ INFO: suspicious RCU usage. ] 4.1.0-rc1+ #1007 Not tainted ------------------------------- drivers/net/ipvlan/ipvlan.h:106 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by dhclient/1076: #0: (rcu_read_lock_bh){......}, at: [] rcu_lock_acquire+0x0/0x26 stack backtrace: CPU: 2 PID: 1076 Comm: dhclient Not tainted 4.1.0-rc1+ #1007 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 0000000000000001 ffff8800d381bac8 ffffffff81a4154f 000000003c1a3c19 ffff8800d4d0a690 ffff8800d381baf8 ffffffff810b849f ffff880117d41148 ffff880117d40000 ffff880117d40068 0000000000000156 ffff8800d381bb18 Call Trace: [] dump_stack+0x4c/0x65 [] lockdep_rcu_suspicious+0x107/0x110 [] ipvlan_port_get_rcu+0x47/0x4e [] ipvlan_queue_xmit+0x35/0x450 [] ? rcu_read_unlock+0x3e/0x5f [] ? local_clock+0x19/0x22 [] ? __lock_is_held+0x39/0x52 [] ipvlan_start_xmit+0x1b/0x44 [] dev_hard_start_xmit+0x2ae/0x467 [] __dev_queue_xmit+0x50a/0x60c [] dev_queue_xmit_sk+0x13/0x15 [] dev_queue_xmit+0x10/0x12 [] packet_sendmsg+0xb6b/0xbdf [] ? mark_lock+0x2e/0x226 [] ? sched_clock_cpu+0x9e/0xb7 [] sock_sendmsg_nosec+0x12/0x1d [] sock_sendmsg+0x29/0x2e [] sock_write_iter+0x70/0x91 [] __vfs_write+0x7e/0xa7 [] vfs_write+0x92/0xe8 [] SyS_write+0x47/0x7e [] system_call_fastpath+0x12/0x6f Fixes: 2ad7bf363841 ("ipvlan: Initial check-in of the IPVLAN driver.") Cc: Mahesh Bandewar Signed-off-by: Cong Wang Acked-by: Mahesh Bandewar Acked-by: Konstantin Khlebnikov Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- drivers/net/ipvlan/ipvlan.h | 5 +++++ drivers/net/ipvlan/ipvlan_core.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/ipvlan/ipvlan.h b/drivers/net/ipvlan/ipvlan.h index 2729f64..af4284b 100644 --- a/drivers/net/ipvlan/ipvlan.h +++ b/drivers/net/ipvlan/ipvlan.h @@ -102,6 +102,11 @@ static inline struct ipvl_port *ipvlan_port_get_rcu(const struct net_device *d) return rcu_dereference(d->rx_handler_data); } +static inline struct ipvl_port *ipvlan_port_get_rcu_bh(const struct net_device *d) +{ + return rcu_dereference_bh(d->rx_handler_data); +} + static inline struct ipvl_port *ipvlan_port_get_rtnl(const struct net_device *d) { return rtnl_dereference(d->rx_handler_data); diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c index 2e19528..8df3268 100644 --- a/drivers/net/ipvlan/ipvlan_core.c +++ b/drivers/net/ipvlan/ipvlan_core.c @@ -495,7 +495,7 @@ static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev) int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev) { struct ipvl_dev *ipvlan = netdev_priv(dev); - struct ipvl_port *port = ipvlan_port_get_rcu(ipvlan->phy_dev); + struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev); if (!port) goto out; -- 1.9.1