From c674ac30c549596295eb0a5af7f4714c0b905b6f Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 16 May 2014 17:04:56 -0400 Subject: [PATCH] macvlan: Fix lockdep warnings with stacked macvlan devices Macvlan devices try to avoid stacking, but that's not always successfull or even desired. As an example, the following configuration is perefectly legal and valid: eth0 <--- macvlan0 <---- vlan0.10 <--- macvlan1 However, this configuration produces the following lockdep trace: [ 115.620418] ====================================================== [ 115.620477] [ INFO: possible circular locking dependency detected ] [ 115.620516] 3.15.0-rc1+ #24 Not tainted [ 115.620540] ------------------------------------------------------- [ 115.620577] ip/1704 is trying to acquire lock: [ 115.620604] (&vlan_netdev_addr_lock_key/1){+.....}, at: [] dev_uc_sync+0x3c/0x80 [ 115.620686] but task is already holding lock: [ 115.620723] (&macvlan_netdev_addr_lock_key){+.....}, at: [] dev_set_rx_mode+0x1e/0x40 [ 115.620795] which lock already depends on the new lock. [ 115.620853] the existing dependency chain (in reverse order) is: [ 115.620894] -> #1 (&macvlan_netdev_addr_lock_key){+.....}: [ 115.620935] [] lock_acquire+0xa2/0x130 [ 115.620974] [] _raw_spin_lock_nested+0x37/0x50 [ 115.621019] [] vlan_dev_set_rx_mode+0x53/0x110 [8021q] [ 115.621066] [] __dev_set_rx_mode+0x57/0xa0 [ 115.621105] [] dev_set_rx_mode+0x26/0x40 [ 115.621143] [] __dev_open+0xde/0x140 [ 115.621174] [] __dev_change_flags+0x9d/0x170 [ 115.621174] [] dev_change_flags+0x29/0x60 [ 115.621174] [] do_setlink+0x321/0x9a0 [ 115.621174] [] rtnl_newlink+0x51f/0x730 [ 115.621174] [] rtnetlink_rcv_msg+0x95/0x250 [ 115.621174] [] netlink_rcv_skb+0xa9/0xc0 [ 115.621174] [] rtnetlink_rcv+0x2a/0x40 [ 115.621174] [] netlink_unicast+0xf0/0x1c0 [ 115.621174] [] netlink_sendmsg+0x2ff/0x740 [ 115.621174] [] sock_sendmsg+0x8b/0xc0 [ 115.621174] [] ___sys_sendmsg+0x369/0x380 [ 115.621174] [] __sys_sendmsg+0x42/0x80 [ 115.621174] [] SyS_sendmsg+0x12/0x20 [ 115.621174] [] system_call_fastpath+0x16/0x1b [ 115.621174] -> #0 (&vlan_netdev_addr_lock_key/1){+.....}: [ 115.621174] [] __lock_acquire+0x1773/0x1a60 [ 115.621174] [] lock_acquire+0xa2/0x130 [ 115.621174] [] _raw_spin_lock_nested+0x37/0x50 [ 115.621174] [] dev_uc_sync+0x3c/0x80 [ 115.621174] [] macvlan_set_mac_lists+0xca/0x110 [macvlan] [ 115.621174] [] __dev_set_rx_mode+0x57/0xa0 [ 115.621174] [] dev_set_rx_mode+0x26/0x40 [ 115.621174] [] __dev_open+0xde/0x140 [ 115.621174] [] __dev_change_flags+0x9d/0x170 [ 115.621174] [] dev_change_flags+0x29/0x60 [ 115.621174] [] do_setlink+0x321/0x9a0 [ 115.621174] [] rtnl_newlink+0x51f/0x730 [ 115.621174] [] rtnetlink_rcv_msg+0x95/0x250 [ 115.621174] [] netlink_rcv_skb+0xa9/0xc0 [ 115.621174] [] rtnetlink_rcv+0x2a/0x40 [ 115.621174] [] netlink_unicast+0xf0/0x1c0 [ 115.621174] [] netlink_sendmsg+0x2ff/0x740 [ 115.621174] [] sock_sendmsg+0x8b/0xc0 [ 115.621174] [] ___sys_sendmsg+0x369/0x380 [ 115.621174] [] __sys_sendmsg+0x42/0x80 [ 115.621174] [] SyS_sendmsg+0x12/0x20 [ 115.621174] [] system_call_fastpath+0x16/0x1b [ 115.621174] other info that might help us debug this: [ 115.621174] Possible unsafe locking scenario: [ 115.621174] CPU0 CPU1 [ 115.621174] ---- ---- [ 115.621174] lock(&macvlan_netdev_addr_lock_key); [ 115.621174] lock(&vlan_netdev_addr_lock_key/1); [ 115.621174] lock(&macvlan_netdev_addr_lock_key); [ 115.621174] lock(&vlan_netdev_addr_lock_key/1); [ 115.621174] *** DEADLOCK *** [ 115.621174] 2 locks held by ip/1704: [ 115.621174] #0: (rtnl_mutex){+.+.+.}, at: [] rtnetlink_rcv+0x1b/0x40 [ 115.621174] #1: (&macvlan_netdev_addr_lock_key){+.....}, at: [] dev_set_rx_mode+0x1e/0x40 [ 115.621174] stack backtrace: [ 115.621174] CPU: 3 PID: 1704 Comm: ip Not tainted 3.15.0-rc1+ #24 [ 115.621174] Hardware name: Hewlett-Packard HP xw8400 Workstation/0A08h, BIOS 786D5 v02.38 10/25/2010 [ 115.621174] ffffffff82339ae0 ffff880465f79568 ffffffff816ee20c ffffffff82339ae0 [ 115.621174] ffff880465f795a8 ffffffff816e9e1b ffff880465f79600 ffff880465b019c8 [ 115.621174] 0000000000000001 0000000000000002 ffff880465b019c8 ffff880465b01230 [ 115.621174] Call Trace: [ 115.621174] [] dump_stack+0x4d/0x66 [ 115.621174] [] print_circular_bug+0x200/0x20e [ 115.621174] [] __lock_acquire+0x1773/0x1a60 [ 115.621174] [] ? trace_hardirqs_on_caller+0xb2/0x1d0 [ 115.621174] [] lock_acquire+0xa2/0x130 [ 115.621174] [] ? dev_uc_sync+0x3c/0x80 [ 115.621174] [] _raw_spin_lock_nested+0x37/0x50 [ 115.621174] [] ? dev_uc_sync+0x3c/0x80 [ 115.621174] [] dev_uc_sync+0x3c/0x80 [ 115.621174] [] macvlan_set_mac_lists+0xca/0x110 [macvlan] [ 115.621174] [] __dev_set_rx_mode+0x57/0xa0 [ 115.621174] [] dev_set_rx_mode+0x26/0x40 [ 115.621174] [] __dev_open+0xde/0x140 [ 115.621174] [] __dev_change_flags+0x9d/0x170 [ 115.621174] [] dev_change_flags+0x29/0x60 [ 115.621174] [] ? mem_cgroup_bad_page_check+0x21/0x30 [ 115.621174] [] do_setlink+0x321/0x9a0 [ 115.621174] [] ? __lock_acquire+0x37c/0x1a60 [ 115.621174] [] rtnl_newlink+0x51f/0x730 [ 115.621174] [] ? rtnl_newlink+0xe9/0x730 [ 115.621174] [] rtnetlink_rcv_msg+0x95/0x250 [ 115.621174] [] ? trace_hardirqs_on+0xd/0x10 [ 115.621174] [] ? rtnetlink_rcv+0x1b/0x40 [ 115.621174] [] ? rtnetlink_rcv+0x40/0x40 [ 115.621174] [] netlink_rcv_skb+0xa9/0xc0 [ 115.621174] [] rtnetlink_rcv+0x2a/0x40 [ 115.621174] [] netlink_unicast+0xf0/0x1c0 [ 115.621174] [] netlink_sendmsg+0x2ff/0x740 [ 115.621174] [] sock_sendmsg+0x8b/0xc0 [ 115.621174] [] ? might_fault+0x5f/0xb0 [ 115.621174] [] ? might_fault+0xa8/0xb0 [ 115.621174] [] ? might_fault+0x5f/0xb0 [ 115.621174] [] ? verify_iovec+0x5e/0xe0 [ 115.621174] [] ___sys_sendmsg+0x369/0x380 [ 115.621174] [] ? __do_page_fault+0x11d/0x570 [ 115.621174] [] ? up_read+0x1f/0x40 [ 115.621174] [] ? __do_page_fault+0x214/0x570 [ 115.621174] [] ? mntput_no_expire+0x6b/0x1c0 [ 115.621174] [] ? mntput_no_expire+0x17/0x1c0 [ 115.621174] [] ? mntput+0x24/0x40 [ 115.621174] [] __sys_sendmsg+0x42/0x80 [ 115.621174] [] SyS_sendmsg+0x12/0x20 [ 115.621174] [] system_call_fastpath+0x16/0x1b Fix this by correctly providing macvlan lockdep class. Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- drivers/net/macvlan.c | 12 ++++++++++-- include/linux/if_macvlan.h | 1 + 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index c5fb9cf95c12..d53e299ae1d9 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -517,6 +517,11 @@ static struct lock_class_key macvlan_netdev_addr_lock_key; #define MACVLAN_STATE_MASK \ ((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT)) +static int macvlan_get_nest_level(struct net_device *dev) +{ + return ((struct macvlan_dev *)netdev_priv(dev))->nest_level; +} + static void macvlan_set_lockdep_class_one(struct net_device *dev, struct netdev_queue *txq, void *_unused) @@ -527,8 +532,9 @@ static void macvlan_set_lockdep_class_one(struct net_device *dev, static void macvlan_set_lockdep_class(struct net_device *dev) { - lockdep_set_class(&dev->addr_list_lock, - &macvlan_netdev_addr_lock_key); + lockdep_set_class_and_subclass(&dev->addr_list_lock, + &macvlan_netdev_addr_lock_key, + macvlan_get_nest_level(dev)); netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL); } @@ -723,6 +729,7 @@ static const struct net_device_ops macvlan_netdev_ops = { .ndo_fdb_add = macvlan_fdb_add, .ndo_fdb_del = macvlan_fdb_del, .ndo_fdb_dump = ndo_dflt_fdb_dump, + .ndo_get_lock_subclass = macvlan_get_nest_level, }; void macvlan_common_setup(struct net_device *dev) @@ -851,6 +858,7 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev, vlan->dev = dev; vlan->port = port; vlan->set_features = MACVLAN_FEATURES; + vlan->nest_level = dev_get_nest_level(lowerdev, netif_is_macvlan) + 1; vlan->mode = MACVLAN_MODE_VEPA; if (data && data[IFLA_MACVLAN_MODE]) diff --git a/include/linux/if_macvlan.h b/include/linux/if_macvlan.h index 7c8b20b120ea..a9a53b12397b 100644 --- a/include/linux/if_macvlan.h +++ b/include/linux/if_macvlan.h @@ -56,6 +56,7 @@ struct macvlan_dev { int numqueues; netdev_features_t tap_features; int minor; + int nest_level; }; static inline void macvlan_count_rx(const struct macvlan_dev *vlan, -- 2.30.2