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Commit dba3ad2a authored by Jack Morgenstein's avatar Jack Morgenstein Committed by Roland Dreier
Browse files

IB/mlx4: Fix lockdep splat for the iboe lock 



Chuck Lever reported the following stack trace:

    =================================
    [ INFO: inconsistent lock state ]
    3.16.0-rc2-00024-g2e78883 #17 Tainted: G            E
    ---------------------------------
    inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
    swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
    (&(&iboe->lock)->rlock){+.?...}, at: [<ffffffffa065f68b>] mlx4_ib_addr_event+0xdb/0x1a0 [mlx4_ib]
    {SOFTIRQ-ON-W} state was registered at:
     [<ffffffff810b3110>] mark_irqflags+0x110/0x170
     [<ffffffff810b4806>] __lock_acquire+0x2c6/0x5b0
     [<ffffffff810b4bd9>] lock_acquire+0xe9/0x120
     [<ffffffff815f7f6e>] _raw_spin_lock+0x3e/0x80
     [<ffffffffa0661084>] mlx4_ib_scan_netdevs+0x34/0x260 [mlx4_ib]
     [<ffffffffa06612db>] mlx4_ib_netdev_event+0x2b/0x40 [mlx4_ib]
     [<ffffffff81522219>] register_netdevice_notifier+0x99/0x1e0
     [<ffffffffa06626e3>] mlx4_ib_add+0x743/0xbc0 [mlx4_ib]
     [<ffffffffa05ec168>] mlx4_add_device+0x48/0xa0 [mlx4_core]
     [<ffffffffa05ec2c3>] mlx4_register_interface+0x73/0xb0 [mlx4_core]
     [<ffffffffa05c505e>] cm_req_handler+0x13e/0x460 [ib_cm]
     [<ffffffff810002e2>] do_one_initcall+0x112/0x1c0
     [<ffffffff810e8264>] do_init_module+0x34/0x190
     [<ffffffff810ea62f>] load_module+0x5cf/0x740
     [<ffffffff810ea939>] SyS_init_module+0x99/0xd0
     [<ffffffff815f8fd2>] system_call_fastpath+0x16/0x1b
    irq event stamp: 336142
    hardirqs last  enabled at (336142): [<ffffffff810612f5>] __local_bh_enable_ip+0xb5/0xc0
    hardirqs last disabled at (336141): [<ffffffff81061296>] __local_bh_enable_ip+0x56/0xc0
    softirqs last  enabled at (336004): [<ffffffff8106123a>] _local_bh_enable+0x4a/0x50
    softirqs last disabled at (336005): [<ffffffff810617a4>] irq_exit+0x44/0xd0

    other info that might help us debug this:
    Possible unsafe locking scenario:

          CPU0
          ----
     lock(&(&iboe->lock)->rlock);
     <Interrupt>
       lock(&(&iboe->lock)->rlock);

    *** DEADLOCK ***

The above problem was caused by the spin lock being taken both in the process
context and in a soft-irq context (in a netdev notifier handler).

The required fix is to use spin_lock/unlock_bh() instead of spin_lock/unlock
on the iboe lock.

Reported-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: default avatarOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
parent bccb84f1

drivers/infiniband/hw/mlx4/main.c

+12 −12
Original line number Original line Diff line number Diff line
@@ -360,7 +360,7 @@ static int eth_link_query_port(struct ib_device *ibdev, u8 port, 
	props->state		= IB_PORT_DOWN;

	props->state		= IB_PORT_DOWN;

	props->phys_state	= state_to_phys_state(props->state);

	props->phys_state	= state_to_phys_state(props->state);

	props->active_mtu	= IB_MTU_256;

	props->active_mtu	= IB_MTU_256;

	spin_lock(&iboe->lock);

	spin_lock_bh(&iboe->lock);

	ndev = iboe->netdevs[port - 1];

	ndev = iboe->netdevs[port - 1];

	if (!ndev)

	if (!ndev)

		goto out_unlock;

		goto out_unlock;
@@ -372,7 +372,7 @@ static int eth_link_query_port(struct ib_device *ibdev, u8 port, 
					IB_PORT_ACTIVE : IB_PORT_DOWN;

					IB_PORT_ACTIVE : IB_PORT_DOWN;

	props->phys_state	= state_to_phys_state(props->state);

	props->phys_state	= state_to_phys_state(props->state);

out_unlock:

out_unlock:

	spin_unlock(&iboe->lock);

	spin_unlock_bh(&iboe->lock);

out:

out:

	mlx4_free_cmd_mailbox(mdev->dev, mailbox);

	mlx4_free_cmd_mailbox(mdev->dev, mailbox);

	return err;

	return err;
@@ -814,11 +814,11 @@ int mlx4_ib_add_mc(struct mlx4_ib_dev *mdev, struct mlx4_ib_qp *mqp, 
	if (!mqp->port)

	if (!mqp->port)

		return 0;

		return 0;





	spin_lock(&mdev->iboe.lock);

	spin_lock_bh(&mdev->iboe.lock);

	ndev = mdev->iboe.netdevs[mqp->port - 1];

	ndev = mdev->iboe.netdevs[mqp->port - 1];

	if (ndev)

	if (ndev)

		dev_hold(ndev);

		dev_hold(ndev);

	spin_unlock(&mdev->iboe.lock);

	spin_unlock_bh(&mdev->iboe.lock);





	if (ndev) {

	if (ndev) {

		ret = 1;

		ret = 1;
@@ -1265,11 +1265,11 @@ static int mlx4_ib_mcg_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) 
	mutex_lock(&mqp->mutex);

	mutex_lock(&mqp->mutex);

	ge = find_gid_entry(mqp, gid->raw);

	ge = find_gid_entry(mqp, gid->raw);

	if (ge) {

	if (ge) {

		spin_lock(&mdev->iboe.lock);

		spin_lock_bh(&mdev->iboe.lock);

		ndev = ge->added ? mdev->iboe.netdevs[ge->port - 1] : NULL;

		ndev = ge->added ? mdev->iboe.netdevs[ge->port - 1] : NULL;

		if (ndev)

		if (ndev)

			dev_hold(ndev);

			dev_hold(ndev);

		spin_unlock(&mdev->iboe.lock);

		spin_unlock_bh(&mdev->iboe.lock);

		if (ndev)

		if (ndev)

			dev_put(ndev);

			dev_put(ndev);

		list_del(&ge->list);

		list_del(&ge->list);
@@ -1554,7 +1554,7 @@ static int mlx4_ib_addr_event(int event, struct net_device *event_netdev, 
		return 0;

		return 0;





	iboe = &ibdev->iboe;

	iboe = &ibdev->iboe;

	spin_lock(&iboe->lock);

	spin_lock_bh(&iboe->lock);





	for (port = 1; port <= ibdev->dev->caps.num_ports; ++port)

	for (port = 1; port <= ibdev->dev->caps.num_ports; ++port)

		if ((netif_is_bond_master(real_dev) &&

		if ((netif_is_bond_master(real_dev) &&
@@ -1564,7 +1564,7 @@ static int mlx4_ib_addr_event(int event, struct net_device *event_netdev, 
			update_gid_table(ibdev, port, gid,

			update_gid_table(ibdev, port, gid,

					 event == NETDEV_DOWN, 0);

					 event == NETDEV_DOWN, 0);





	spin_unlock(&iboe->lock);

	spin_unlock_bh(&iboe->lock);

	return 0;

	return 0;





}

}
@@ -1742,7 +1742,7 @@ static int mlx4_ib_init_gid_table(struct mlx4_ib_dev *ibdev) 
	}

	}





	read_lock(&dev_base_lock);

	read_lock(&dev_base_lock);

	spin_lock(&iboe->lock);

	spin_lock_bh(&iboe->lock);





	for_each_netdev(&init_net, dev) {

	for_each_netdev(&init_net, dev) {

		u8 port = mlx4_ib_get_dev_port(dev, ibdev);

		u8 port = mlx4_ib_get_dev_port(dev, ibdev);
@@ -1753,7 +1753,7 @@ static int mlx4_ib_init_gid_table(struct mlx4_ib_dev *ibdev) 
		}

		}

	}

	}





	spin_unlock(&iboe->lock);

	spin_unlock_bh(&iboe->lock);

	read_unlock(&dev_base_lock);

	read_unlock(&dev_base_lock);

out:

out:

	return err;

	return err;
@@ -1770,7 +1770,7 @@ static void mlx4_ib_scan_netdevs(struct mlx4_ib_dev *ibdev, 




	iboe = &ibdev->iboe;

	iboe = &ibdev->iboe;





	spin_lock(&iboe->lock);

	spin_lock_bh(&iboe->lock);

	mlx4_foreach_ib_transport_port(port, ibdev->dev) {

	mlx4_foreach_ib_transport_port(port, ibdev->dev) {

		enum ib_port_state	port_state = IB_PORT_NOP;

		enum ib_port_state	port_state = IB_PORT_NOP;

		struct net_device *old_master = iboe->masters[port - 1];

		struct net_device *old_master = iboe->masters[port - 1];
@@ -1842,7 +1842,7 @@ static void mlx4_ib_scan_netdevs(struct mlx4_ib_dev *ibdev, 
		}

		}

	}

	}





	spin_unlock(&iboe->lock);

	spin_unlock_bh(&iboe->lock);





	if (update_qps_port > 0)

	if (update_qps_port > 0)

		mlx4_ib_update_qps(ibdev, dev, update_qps_port);

		mlx4_ib_update_qps(ibdev, dev, update_qps_port);