Hi,
I ran into the following lockdep complaint:
[ 7.059561] INFO: trying to register non-static key.
[ 7.059566] the code is fine but needs lockdep annotation.
[ 7.059570] turning off the locking correctness validator.
[ 7.059579] CPU: 6 PID: 6 Comm: kworker/u32:0 Not tainted 4.9.0-02683-g784243e-dirty #77
[ 7.059582] Hardware name: IBM 2964 N96 704 (LPAR)
[ 7.061260] Workqueue: mlx5e mlx5e_set_rx_mode_work [mlx5_core]
[ 7.061268] Stack:
[ 7.061270] 00000000f95739c0 00000000f9573a50 0000000000000003 0000000000000000
[ 7.061278] 00000000f9573af0 00000000f9573a68 00000000f9573a68 0000000000000020
[ 7.061286] 0000000000000000 0000000000000020 000000000000000a 000000000000000a
[ 7.061294] 000000000000000c 00000000f9573ab8 0000000000000000 0000000000000000
[ 7.061301] 00000000008a1038 0000000000112a50 00000000f9573a50 00000000f9573aa8
[ 7.061314] Call Trace:
[ 7.061321] ([<000000000011292a>] show_trace+0x8a/0xe0)
[ 7.061327] [<0000000000112a00>] show_stack+0x80/0xd8
[ 7.061334] [<00000000005cdce6>] dump_stack+0x96/0xd8
[ 7.061338] [<00000000001ae352>] register_lock_class+0x1d2/0x530
[ 7.061341] [<00000000001b33f6>] __lock_acquire+0xfe/0x7d8
[ 7.061345] [<00000000001b4394>] lock_acquire+0x30c/0x358
[ 7.061352] [<000000000089454c>] _raw_spin_lock_bh+0x64/0xa0
[ 7.062171] [<000003ff81465858>] mlx5e_set_rx_mode_work+0x248/0x490 [mlx5_core]
[ 7.062178] [<0000000000163864>] process_one_work+0x41c/0x830
[ 7.062181] [<0000000000163f2c>] worker_thread+0x2b4/0x478
[ 7.062186] [<000000000016c46c>] kthread+0x15c/0x170
[ 7.062190] [<0000000000895a52>] kernel_thread_starter+0x6/0xc
[ 7.062193] [<0000000000895a4c>] kernel_thread_starter+0x0/0xc
[ 7.062196] INFO: lockdep is turned off.
The problematic lock is net_device.addr_list_lock whose usage is
asynchronously triggered by:
mlx5e_add -> mlx5e_attach -> mlx5e_attach_netdev -> mlx5e_nic_enable
[workq] mlx5e_set_rx_mode_work -> mlx5e_handle_netdev_addr -> mlx5e_sync_netdev_addr
Initialization of this lock is triggered by:
mlx5e_add -> register_netdev
...after the call to mlx5e_attach which is obviously racy.
Regards,
Sebastian
On Tue, Dec 13, 2016 at 3:22 PM, Sebastian Ott
<[email protected]> wrote:
> Hi,
>
> I ran into the following lockdep complaint:
>
> [ 7.059561] INFO: trying to register non-static key.
> [ 7.059566] the code is fine but needs lockdep annotation.
> [ 7.059570] turning off the locking correctness validator.
> [ 7.059579] CPU: 6 PID: 6 Comm: kworker/u32:0 Not tainted 4.9.0-02683-g784243e-dirty #77
> [ 7.059582] Hardware name: IBM 2964 N96 704 (LPAR)
> [ 7.061260] Workqueue: mlx5e mlx5e_set_rx_mode_work [mlx5_core]
> [ 7.061268] Stack:
> [ 7.061270] 00000000f95739c0 00000000f9573a50 0000000000000003 0000000000000000
> [ 7.061278] 00000000f9573af0 00000000f9573a68 00000000f9573a68 0000000000000020
> [ 7.061286] 0000000000000000 0000000000000020 000000000000000a 000000000000000a
> [ 7.061294] 000000000000000c 00000000f9573ab8 0000000000000000 0000000000000000
> [ 7.061301] 00000000008a1038 0000000000112a50 00000000f9573a50 00000000f9573aa8
> [ 7.061314] Call Trace:
> [ 7.061321] ([<000000000011292a>] show_trace+0x8a/0xe0)
> [ 7.061327] [<0000000000112a00>] show_stack+0x80/0xd8
> [ 7.061334] [<00000000005cdce6>] dump_stack+0x96/0xd8
> [ 7.061338] [<00000000001ae352>] register_lock_class+0x1d2/0x530
> [ 7.061341] [<00000000001b33f6>] __lock_acquire+0xfe/0x7d8
> [ 7.061345] [<00000000001b4394>] lock_acquire+0x30c/0x358
> [ 7.061352] [<000000000089454c>] _raw_spin_lock_bh+0x64/0xa0
> [ 7.062171] [<000003ff81465858>] mlx5e_set_rx_mode_work+0x248/0x490 [mlx5_core]
> [ 7.062178] [<0000000000163864>] process_one_work+0x41c/0x830
> [ 7.062181] [<0000000000163f2c>] worker_thread+0x2b4/0x478
> [ 7.062186] [<000000000016c46c>] kthread+0x15c/0x170
> [ 7.062190] [<0000000000895a52>] kernel_thread_starter+0x6/0xc
> [ 7.062193] [<0000000000895a4c>] kernel_thread_starter+0x0/0xc
> [ 7.062196] INFO: lockdep is turned off.
>
> The problematic lock is net_device.addr_list_lock whose usage is
> asynchronously triggered by:
>
> mlx5e_add -> mlx5e_attach -> mlx5e_attach_netdev -> mlx5e_nic_enable
> [workq] mlx5e_set_rx_mode_work -> mlx5e_handle_netdev_addr -> mlx5e_sync_netdev_addr
>
> Initialization of this lock is triggered by:
> mlx5e_add -> register_netdev
>
> ...after the call to mlx5e_attach which is obviously racy.
>
Thanks Sebastian for the report,
indeed there is an issue, I wonder why the net_device.addr_list_lock
is initialized so late (at register_netdevice) IMHO it should be
initialized at
alloc_netdev_mqs->dev_addr_init
where all the other net_device fields are initialized!
We will handle this.
Thanks,
Saeed.