diff options
| author | Ingo Molnar <mingo@elte.hu> | 2009-08-04 21:16:58 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-08-05 08:35:11 -0700 |
| commit | 0bf52b981770cbf006323bab5177f2858a196766 (patch) | |
| tree | cf45ebbd91aacd23d170e8c320d9922c81cc2d0e | |
| parent | 357eb46d8f275b4e8484541234ea3ba06065e258 (diff) | |
net: Fix spinlock use in alloc_netdev_mq()
-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 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>
| -rw-r--r-- | net/core/dev.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 43e61ba7bd95..6a94475aee85 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4007,9 +4007,7 @@ static void dev_unicast_flush(struct net_device *dev) static void dev_unicast_init(struct net_device *dev) { - netif_addr_lock_bh(dev); __hw_addr_init(&dev->uc); - netif_addr_unlock_bh(dev); } |