_dev_init+0x115/0x164
[    2.284005]  [<7900104f>] do_one_initcall+0x4a/0x11a
[    2.284005]  [<798f5b8a>] ? net_dev_init+0x0/0x164
[    2.284005]  [<79066f6d>] ? register_irq_proc+0x8c/0xa8
[    2.284005]  [<798cc29a>] do_basic_setup+0x42/0x52
[    2.284005]  [<798cc30a>] kernel_init+0x60/0xa1
[    2.284005]  [<798cc2aa>] ? kernel_init+0x0/0xa1
[    2.284005]  [<79003e03>] kernel_thread_helper+0x7/0x10
[    2.284078] device: 'lo': device_add
[    2.288248] initcall net_dev_init+0x0/0x164 returned 0 after 11718 usecs
[    2.292010] calling  neigh_init+0x0/0x66 @ 1
[    2.296010] initcall neigh_init+0x0/0x66 returned 0 after 0 usecs

it's using an zero-initialized spinlock. This is a side-effect of:

        dev_unicast_init(dev);

in alloc_netdev_mq() making use of dev->addr_list_lock.

The device has just been allocated freshly, it's not accessible
anywhere yet so no locking is needed at all - in fact it's wrong
to lock it here (the lock isnt initialized yet).

This bug was introduced via:

| commit a6ac65db2329e7685299666f5f7b6093c7b0f3a0
| Date:   Thu Jul 30 01:06:12 2009 +0000
|
|     net: restore the original spinlock to protect unicast list

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jiri Pirko <jpirko@redhat.com>
Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
@|^#ž