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macvlan: Fix lockdep warnings with stacked macvlan devices
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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+ hardkernel#24 Not tainted
[  115.620540] -------------------------------------------------------
[  115.620577] ip/1704 is trying to acquire lock:
[  115.620604]  (&vlan_netdev_addr_lock_key/1){+.....}, at: [<ffffffff815df49c>] dev_uc_sync+0x3c/0x80
[  115.620686]
but task is already holding lock:
[  115.620723]  (&macvlan_netdev_addr_lock_key){+.....}, at: [<ffffffff815da5be>] 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]        [<ffffffff810d57f2>] lock_acquire+0xa2/0x130
[  115.620974]        [<ffffffff816f62e7>] _raw_spin_lock_nested+0x37/0x50
[  115.621019]        [<ffffffffa07296c3>] vlan_dev_set_rx_mode+0x53/0x110 [8021q]
[  115.621066]        [<ffffffff815da557>] __dev_set_rx_mode+0x57/0xa0
[  115.621105]        [<ffffffff815da5c6>] dev_set_rx_mode+0x26/0x40
[  115.621143]        [<ffffffff815da6be>] __dev_open+0xde/0x140
[  115.621174]        [<ffffffff815da9ad>] __dev_change_flags+0x9d/0x170
[  115.621174]        [<ffffffff815daaa9>] dev_change_flags+0x29/0x60
[  115.621174]        [<ffffffff815e7f11>] do_setlink+0x321/0x9a0
[  115.621174]        [<ffffffff815ea59f>] rtnl_newlink+0x51f/0x730
[  115.621174]        [<ffffffff815e6e75>] rtnetlink_rcv_msg+0x95/0x250
[  115.621174]        [<ffffffff81608b19>] netlink_rcv_skb+0xa9/0xc0
[  115.621174]        [<ffffffff815e6dca>] rtnetlink_rcv+0x2a/0x40
[  115.621174]        [<ffffffff81608150>] netlink_unicast+0xf0/0x1c0
[  115.621174]        [<ffffffff8160851f>] netlink_sendmsg+0x2ff/0x740
[  115.621174]        [<ffffffff815bc9db>] sock_sendmsg+0x8b/0xc0
[  115.621174]        [<ffffffff815bd4b9>] ___sys_sendmsg+0x369/0x380
[  115.621174]        [<ffffffff815bdbb2>] __sys_sendmsg+0x42/0x80
[  115.621174]        [<ffffffff815bdc02>] SyS_sendmsg+0x12/0x20
[  115.621174]        [<ffffffff816ffd69>] system_call_fastpath+0x16/0x1b
[  115.621174]
-> #0 (&vlan_netdev_addr_lock_key/1){+.....}:
[  115.621174]        [<ffffffff810d4d43>] __lock_acquire+0x1773/0x1a60
[  115.621174]        [<ffffffff810d57f2>] lock_acquire+0xa2/0x130
[  115.621174]        [<ffffffff816f62e7>] _raw_spin_lock_nested+0x37/0x50
[  115.621174]        [<ffffffff815df49c>] dev_uc_sync+0x3c/0x80
[  115.621174]        [<ffffffffa0696d2a>] macvlan_set_mac_lists+0xca/0x110 [macvlan]
[  115.621174]        [<ffffffff815da557>] __dev_set_rx_mode+0x57/0xa0
[  115.621174]        [<ffffffff815da5c6>] dev_set_rx_mode+0x26/0x40
[  115.621174]        [<ffffffff815da6be>] __dev_open+0xde/0x140
[  115.621174]        [<ffffffff815da9ad>] __dev_change_flags+0x9d/0x170
[  115.621174]        [<ffffffff815daaa9>] dev_change_flags+0x29/0x60
[  115.621174]        [<ffffffff815e7f11>] do_setlink+0x321/0x9a0
[  115.621174]        [<ffffffff815ea59f>] rtnl_newlink+0x51f/0x730
[  115.621174]        [<ffffffff815e6e75>] rtnetlink_rcv_msg+0x95/0x250
[  115.621174]        [<ffffffff81608b19>] netlink_rcv_skb+0xa9/0xc0
[  115.621174]        [<ffffffff815e6dca>] rtnetlink_rcv+0x2a/0x40
[  115.621174]        [<ffffffff81608150>] netlink_unicast+0xf0/0x1c0
[  115.621174]        [<ffffffff8160851f>] netlink_sendmsg+0x2ff/0x740
[  115.621174]        [<ffffffff815bc9db>] sock_sendmsg+0x8b/0xc0
[  115.621174]        [<ffffffff815bd4b9>] ___sys_sendmsg+0x369/0x380
[  115.621174]        [<ffffffff815bdbb2>] __sys_sendmsg+0x42/0x80
[  115.621174]        [<ffffffff815bdc02>] SyS_sendmsg+0x12/0x20
[  115.621174]        [<ffffffff816ffd69>] 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: [<ffffffff815e6dbb>] rtnetlink_rcv+0x1b/0x40
[  115.621174]  #1:  (&macvlan_netdev_addr_lock_key){+.....}, at: [<ffffffff815da5be>] dev_set_rx_mode+0x1e/0x40
[  115.621174]
stack backtrace:
[  115.621174] CPU: 3 PID: 1704 Comm: ip Not tainted 3.15.0-rc1+ hardkernel#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]  [<ffffffff816ee20c>] dump_stack+0x4d/0x66
[  115.621174]  [<ffffffff816e9e1b>] print_circular_bug+0x200/0x20e
[  115.621174]  [<ffffffff810d4d43>] __lock_acquire+0x1773/0x1a60
[  115.621174]  [<ffffffff810d3172>] ? trace_hardirqs_on_caller+0xb2/0x1d0
[  115.621174]  [<ffffffff810d57f2>] lock_acquire+0xa2/0x130
[  115.621174]  [<ffffffff815df49c>] ? dev_uc_sync+0x3c/0x80
[  115.621174]  [<ffffffff816f62e7>] _raw_spin_lock_nested+0x37/0x50
[  115.621174]  [<ffffffff815df49c>] ? dev_uc_sync+0x3c/0x80
[  115.621174]  [<ffffffff815df49c>] dev_uc_sync+0x3c/0x80
[  115.621174]  [<ffffffffa0696d2a>] macvlan_set_mac_lists+0xca/0x110 [macvlan]
[  115.621174]  [<ffffffff815da557>] __dev_set_rx_mode+0x57/0xa0
[  115.621174]  [<ffffffff815da5c6>] dev_set_rx_mode+0x26/0x40
[  115.621174]  [<ffffffff815da6be>] __dev_open+0xde/0x140
[  115.621174]  [<ffffffff815da9ad>] __dev_change_flags+0x9d/0x170
[  115.621174]  [<ffffffff815daaa9>] dev_change_flags+0x29/0x60
[  115.621174]  [<ffffffff811e1db1>] ? mem_cgroup_bad_page_check+0x21/0x30
[  115.621174]  [<ffffffff815e7f11>] do_setlink+0x321/0x9a0
[  115.621174]  [<ffffffff810d394c>] ? __lock_acquire+0x37c/0x1a60
[  115.621174]  [<ffffffff815ea59f>] rtnl_newlink+0x51f/0x730
[  115.621174]  [<ffffffff815ea169>] ? rtnl_newlink+0xe9/0x730
[  115.621174]  [<ffffffff815e6e75>] rtnetlink_rcv_msg+0x95/0x250
[  115.621174]  [<ffffffff810d329d>] ? trace_hardirqs_on+0xd/0x10
[  115.621174]  [<ffffffff815e6dbb>] ? rtnetlink_rcv+0x1b/0x40
[  115.621174]  [<ffffffff815e6de0>] ? rtnetlink_rcv+0x40/0x40
[  115.621174]  [<ffffffff81608b19>] netlink_rcv_skb+0xa9/0xc0
[  115.621174]  [<ffffffff815e6dca>] rtnetlink_rcv+0x2a/0x40
[  115.621174]  [<ffffffff81608150>] netlink_unicast+0xf0/0x1c0
[  115.621174]  [<ffffffff8160851f>] netlink_sendmsg+0x2ff/0x740
[  115.621174]  [<ffffffff815bc9db>] sock_sendmsg+0x8b/0xc0
[  115.621174]  [<ffffffff8119d4af>] ? might_fault+0x5f/0xb0
[  115.621174]  [<ffffffff8119d4f8>] ? might_fault+0xa8/0xb0
[  115.621174]  [<ffffffff8119d4af>] ? might_fault+0x5f/0xb0
[  115.621174]  [<ffffffff815cb51e>] ? verify_iovec+0x5e/0xe0
[  115.621174]  [<ffffffff815bd4b9>] ___sys_sendmsg+0x369/0x380
[  115.621174]  [<ffffffff816faa0d>] ? __do_page_fault+0x11d/0x570
[  115.621174]  [<ffffffff810cfe9f>] ? up_read+0x1f/0x40
[  115.621174]  [<ffffffff816fab04>] ? __do_page_fault+0x214/0x570
[  115.621174]  [<ffffffff8120a10b>] ? mntput_no_expire+0x6b/0x1c0
[  115.621174]  [<ffffffff8120a0b7>] ? mntput_no_expire+0x17/0x1c0
[  115.621174]  [<ffffffff8120a284>] ? mntput+0x24/0x40
[  115.621174]  [<ffffffff815bdbb2>] __sys_sendmsg+0x42/0x80
[  115.621174]  [<ffffffff815bdc02>] SyS_sendmsg+0x12/0x20
[  115.621174]  [<ffffffff816ffd69>] system_call_fastpath+0x16/0x1b

Fix this by correctly providing macvlan lockdep class.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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@davem330
Vlad Yasevich authored and davem330 committed May 17, 2014
1 parent d38569a commit c674ac3
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Showing 2 changed files with 11 additions and 2 deletions.
12 changes: 10 additions & 2 deletions drivers/net/macvlan.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand All @@ -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);
}

Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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])
Expand Down
1 change: 1 addition & 0 deletions include/linux/if_macvlan.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand Down

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