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Commit 26574401 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by David S. Miller
Browse files

net: Fix ipoib rtnl_lock sysfs deadlock. 



Network device sysfs files that grab the rtnl_lock unconditionally
will deadlock if accessed when the network device is being
unregistered.  So use trylock and syscall_restart to avoid this
deadlock.

Signed-off-by: default avatarEric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent af38f298

drivers/infiniband/ulp/ipoib/ipoib_cm.c

+4 −2
Original line number Diff line number Diff line
@@ -1455,13 +1455,15 @@ static ssize_t set_mode(struct device *d, struct device_attribute *attr, 
	struct net_device *dev = to_net_dev(d);

	struct ipoib_dev_priv *priv = netdev_priv(dev);



	if (!rtnl_trylock())

		return restart_syscall();



	/* flush paths if we switch modes so that connections are restarted */

	if (IPOIB_CM_SUPPORTED(dev->dev_addr) && !strcmp(buf, "connected\n")) {

		set_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);

		ipoib_warn(priv, "enabling connected mode "

			   "will cause multicast packet drops\n");



		rtnl_lock();

		dev->features &= ~(NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO);

		rtnl_unlock();

		priv->tx_wr.send_flags &= ~IB_SEND_IP_CSUM;
@@ -1473,7 +1475,6 @@ static ssize_t set_mode(struct device *d, struct device_attribute *attr, 
	if (!strcmp(buf, "datagram\n")) {

		clear_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);



		rtnl_lock();

		if (test_bit(IPOIB_FLAG_CSUM, &priv->flags)) {

			dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;

			if (priv->hca_caps & IB_DEVICE_UD_TSO)
@@ -1485,6 +1486,7 @@ static ssize_t set_mode(struct device *d, struct device_attribute *attr, 


		return count;

	}

	rtnl_unlock();



	return -EINVAL;

}

drivers/infiniband/ulp/ipoib/ipoib_vlan.c

+4 −2
Original line number Diff line number Diff line
@@ -61,7 +61,8 @@ int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey) 


	ppriv = netdev_priv(pdev);



	rtnl_lock();

	if (!rtnl_trylock())

		return restart_syscall();

	mutex_lock(&ppriv->vlan_mutex);



	/*
@@ -167,7 +168,8 @@ int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey) 


	ppriv = netdev_priv(pdev);



	rtnl_lock();

	if (!rtnl_trylock())

		return restart_syscall();

	mutex_lock(&ppriv->vlan_mutex);

	list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {

		if (priv->pkey == pkey) {