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0bf52b9817
-tip testing found this lockdep warning:
[ 2.272010] calling net_dev_init+0x0/0x164 @ 1
[ 2.276033] device class 'net': registering
[ 2.280191] INFO: trying to register non-static key.
[ 2.284005] the code is fine but needs lockdep annotation.
[ 2.284005] turning off the locking correctness validator.
[ 2.284005] Pid: 1, comm: swapper Not tainted 2.6.31-rc5-tip #1145
[ 2.284005] Call Trace:
[ 2.284005] [<7958eb4e>] ? printk+0xf/0x11
[ 2.284005] [<7904f83c>] __lock_acquire+0x11b/0x622
[ 2.284005] [<7908c9b7>] ? alloc_debug_processing+0xf9/0x144
[ 2.284005] [<7904e2be>] ? mark_held_locks+0x3a/0x52
[ 2.284005] [<7908dbc4>] ? kmem_cache_alloc+0xa8/0x13f
[ 2.284005] [<7904e475>] ? trace_hardirqs_on_caller+0xa2/0xc3
[ 2.284005] [<7904fdf6>] lock_acquire+0xb3/0xd0
[ 2.284005] [<79489678>] ? alloc_netdev_mq+0xf5/0x1ad
[ 2.284005] [<79591514>] _spin_lock_bh+0x2d/0x5d
[ 2.284005] [<79489678>] ? alloc_netdev_mq+0xf5/0x1ad
[ 2.284005] [<79489678>] alloc_netdev_mq+0xf5/0x1ad
[ 2.284005] [<793a38f2>] ? loopback_setup+0x0/0x74
[ 2.284005] [<798eecd0>] loopback_net_init+0x20/0x5d
[ 2.284005] [<79483efb>] register_pernet_device+0x23/0x4b
[ 2.284005] [<798f5c9f>] net_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
|
||
|---|---|---|
| .. | ||
| datagram.c | ||
| dev_mcast.c | ||
| dev.c | ||
| drop_monitor.c | ||
| dst.c | ||
| ethtool.c | ||
| fib_rules.c | ||
| filter.c | ||
| flow.c | ||
| gen_estimator.c | ||
| gen_stats.c | ||
| iovec.c | ||
| kmap_skb.h | ||
| link_watch.c | ||
| Makefile | ||
| neighbour.c | ||
| net_namespace.c | ||
| net-sysfs.c | ||
| net-sysfs.h | ||
| net-traces.c | ||
| netevent.c | ||
| netpoll.c | ||
| pktgen.c | ||
| request_sock.c | ||
| rtnetlink.c | ||
| scm.c | ||
| skb_dma_map.c | ||
| skbuff.c | ||
| sock.c | ||
| stream.c | ||
| sysctl_net_core.c | ||
| user_dma.c | ||
| utils.c | ||