diff options
| author |   Erez Shitrit <erezsh@mellanox.com> | 2016-06-04 15:15:20 +0300 |
|---|---|---|
| committer |   Doug Ledford <dledford@redhat.com> | 2016-06-07 09:50:53 -0400 |
| commit | 198b12f77084244d310888dd5d643083cb5c2aa1 (patch) | |
| tree | df3556483d4afdedfd1e92efcbfa1ed3b3a759af /drivers/infiniband/ulp/ipoib/ipoib_cm.c | |
| parent | IB/core: Fix query port failure in RoCE (diff) | |
| download | linux-dev-198b12f77084244d310888dd5d643083cb5c2aa1.tar.xz linux-dev-198b12f77084244d310888dd5d643083cb5c2aa1.zip | |
IB/IPoIB: Fix race between ipoib_remove_one to sysfs functions
In ipoib_remove_one the driver holds the rtnl_lock and tries to do some
operation like dev_change_flags or unregister_netdev, while sysfs
callback like ipoib_vlan_delete holds sysfs mutex and tries to hold the
rtnl_lock via rtnl_trylock() and restart_syscall() if the lock is not
free, meanwhile ipoib_remove_one tries to get the sysfs lock in order to
free its sysfs directory, and we will get a->b, b->a deadlock.
Trace like the following:
schedule+0x37/0x80
schedule_preempt_disabled+0xe/0x10
__mutex_lock_slowpath+0xb5/0x120
mutex_lock+0x23/0x40
rtnl_lock+0x15/0x20
netdev_run_todo+0x17c/0x320
rtnl_unlock+0xe/0x10
ipoib_vlan_delete+0x11b/0x1b0 [ib_ipoib]
delete_child+0x54/0x80 [ib_ipoib]
dev_attr_store+0x18/0x30
sysfs_kf_write+0x37/0x40
mutex_lock+0x16/0x40
SyS_write+0x55/0xc0
entry_SYSCALL_64_fastpath+0x16/0x75
And
schedule+0x37/0x80
__kernfs_remove+0x1a8/0x260
? wake_atomic_t_function+0x60/0x60
kernfs_remove+0x25/0x40
sysfs_remove_dir+0x50/0x80
kobject_del+0x18/0x50
device_del+0x19f/0x260
netdev_unregister_kobject+0x6a/0x80
rollback_registered_many+0x1fd/0x340
rollback_registered+0x3c/0x70
unregister_netdevice_queue+0x55/0xc0
unregister_netdev+0x20/0x30
ipoib_remove_one+0x114/0x1b0 [ib_ipoib]
ib_unregister_client+0x4a/0x170 [ib_core]
? find_module_all+0x71/0xa0
ipoib_cleanup_module+0x10/0x94 [ib_ipoib]
SyS_delete_module+0x1b5/0x210
entry_SYSCALL_64_fastpath+0x16/0x75
The fix is by checking the flag IPOIB_FLAG_INTF_ON_DESTROY in order to
get out from the sysfs function.
Fixes: 862096a8bbf8 ("IB/ipoib: Add more rtnl_link_ops callbacks")
Fixes: 9baa0b036410 ("IB/ipoib: Add rtnl_link_ops support")
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/ulp/ipoib/ipoib_cm.c')
| -rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib_cm.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c index b2f42835d76d..951d9abcca8b 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c @@ -1486,6 +1486,10 @@ static ssize_t set_mode(struct device *d, struct device_attribute *attr, { struct net_device *dev = to_net_dev(d); int ret; + struct ipoib_dev_priv *priv = netdev_priv(dev); + + if (test_bit(IPOIB_FLAG_GOING_DOWN, &priv->flags)) + return -EPERM; if (!rtnl_trylock()) return restart_syscall(); |