android_kernel_xiaomi_sm8350/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
Roland Dreier cbbe1efa49 IPoIB: Fix deadlock between ipoib_open() and child interface create
Fix a deadlock between child interface creation/deletion and ipoib
start/stop.  The former takes vlan_mutex, and then might take RTNL via
register_netdev()/unregister_netdev().  The latter is executed with
RTNL held, and tries to take vlan_mutex, which can lead to an AB-BA
deadlock.

Fix this by having the child interface creation/deletion code take the
RTNL first so vlan_mutex always nests inside RTNL.  We can use
register_netdevice() for child interfaces because we form the
interface name from the parent interface and hence don't need the '%'
expansion of register_netdev().

Reported-by: Yossi Etigin <yosefe@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2009-01-14 21:44:39 -08:00

186 lines
4.7 KiB
C

/*
* Copyright (c) 2004 Topspin Communications. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
#include "ipoib.h"
static ssize_t show_parent(struct device *d, struct device_attribute *attr,
char *buf)
{
struct net_device *dev = to_net_dev(d);
struct ipoib_dev_priv *priv = netdev_priv(dev);
return sprintf(buf, "%s\n", priv->parent->name);
}
static DEVICE_ATTR(parent, S_IRUGO, show_parent, NULL);
int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
{
struct ipoib_dev_priv *ppriv, *priv;
char intf_name[IFNAMSIZ];
int result;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
ppriv = netdev_priv(pdev);
rtnl_lock();
mutex_lock(&ppriv->vlan_mutex);
/*
* First ensure this isn't a duplicate. We check the parent device and
* then all of the child interfaces to make sure the Pkey doesn't match.
*/
if (ppriv->pkey == pkey) {
result = -ENOTUNIQ;
goto err;
}
list_for_each_entry(priv, &ppriv->child_intfs, list) {
if (priv->pkey == pkey) {
result = -ENOTUNIQ;
goto err;
}
}
snprintf(intf_name, sizeof intf_name, "%s.%04x",
ppriv->dev->name, pkey);
priv = ipoib_intf_alloc(intf_name);
if (!priv) {
result = -ENOMEM;
goto err;
}
priv->max_ib_mtu = ppriv->max_ib_mtu;
/* MTU will be reset when mcast join happens */
priv->dev->mtu = IPOIB_UD_MTU(priv->max_ib_mtu);
priv->mcast_mtu = priv->admin_mtu = priv->dev->mtu;
set_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags);
result = ipoib_set_dev_features(priv, ppriv->ca);
if (result)
goto device_init_failed;
priv->pkey = pkey;
memcpy(priv->dev->dev_addr, ppriv->dev->dev_addr, INFINIBAND_ALEN);
priv->dev->broadcast[8] = pkey >> 8;
priv->dev->broadcast[9] = pkey & 0xff;
result = ipoib_dev_init(priv->dev, ppriv->ca, ppriv->port);
if (result < 0) {
ipoib_warn(ppriv, "failed to initialize subinterface: "
"device %s, port %d",
ppriv->ca->name, ppriv->port);
goto device_init_failed;
}
result = register_netdevice(priv->dev);
if (result) {
ipoib_warn(priv, "failed to initialize; error %i", result);
goto register_failed;
}
priv->parent = ppriv->dev;
ipoib_create_debug_files(priv->dev);
if (ipoib_cm_add_mode_attr(priv->dev))
goto sysfs_failed;
if (ipoib_add_pkey_attr(priv->dev))
goto sysfs_failed;
if (ipoib_add_umcast_attr(priv->dev))
goto sysfs_failed;
if (device_create_file(&priv->dev->dev, &dev_attr_parent))
goto sysfs_failed;
list_add_tail(&priv->list, &ppriv->child_intfs);
mutex_unlock(&ppriv->vlan_mutex);
rtnl_unlock();
return 0;
sysfs_failed:
ipoib_delete_debug_files(priv->dev);
unregister_netdevice(priv->dev);
register_failed:
ipoib_dev_cleanup(priv->dev);
device_init_failed:
free_netdev(priv->dev);
err:
mutex_unlock(&ppriv->vlan_mutex);
rtnl_unlock();
return result;
}
int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey)
{
struct ipoib_dev_priv *ppriv, *priv, *tpriv;
int ret = -ENOENT;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
ppriv = netdev_priv(pdev);
rtnl_lock();
mutex_lock(&ppriv->vlan_mutex);
list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {
if (priv->pkey == pkey) {
unregister_netdevice(priv->dev);
ipoib_dev_cleanup(priv->dev);
list_del(&priv->list);
free_netdev(priv->dev);
ret = 0;
break;
}
}
mutex_unlock(&ppriv->vlan_mutex);
rtnl_unlock();
return ret;
}