[-next] fs/eventpoll.c:545 suspicious rcu_dereference_check() usage

[-next] fs/eventpoll.c:545 suspicious rcu_dereference_check() usage

[Sergey Senozhatsky]

Hello,

got this with today's linux-next

[    3.163894] ===============================
[    3.163895] [ INFO: suspicious RCU usage. ]
[    3.163897] 3.9.0-rc3-next-20130322-dbg-dirty #1 Not tainted
[    3.163898] -------------------------------
[    3.163900] fs/eventpoll.c:545 suspicious rcu_dereference_check() usage!
[    3.163900] other info that might help us debug this:
[    3.163902] rcu_scheduler_active = 1, debug_locks = 1
[    3.163903] 2 locks held by ata_id/763:
[    3.163915]  #0:  (&pipe->wait){......}, at: [<ffffffff810757a7>] __wake_up_sync_key+0x37/0x80
[    3.163923]  #1:  (&(&ep->lock)->rlock){......}, at: [<ffffffff811bb4a9>] ep_poll_callback+0x59/0x1f0
[    3.163924] 	stack backtrace:
[    3.163927] Pid: 763, comm: ata_id Not tainted 3.9.0-rc3-next-20130322-dbg-dirty #1
[    3.163929] Call Trace:
[    3.163940]  [<ffffffff810a7c66>] lockdep_rcu_suspicious+0xe6/0x130
[    3.163945]  [<ffffffff811bb61f>] ep_poll_callback+0x1cf/0x1f0
[    3.163949]  [<ffffffff81074765>] __wake_up_common+0x55/0x90
[    3.163952]  [<ffffffff810757c3>] __wake_up_sync_key+0x53/0x80
[    3.163957]  [<ffffffff811775f8>] pipe_write+0x448/0x590
[    3.163962]  [<ffffffff8116df70>] do_sync_write+0x80/0xb0
[    3.163965]  [<ffffffff8116e938>] vfs_write+0xa8/0x180
[    3.163968]  [<ffffffff8116ec95>] SyS_write+0x55/0xb0
[    3.163975]  [<ffffffff81620506>] system_call_fastpath+0x1a/0x1f



	-ss

Re: [-next] fs/eventpoll.c:545 suspicious rcu_dereference_check() usage

[Eric Wong]

Sergey Senozhatsky <sergey.senozhatsky@gmail.com> wrote:
> [    3.163894] ===============================
> [    3.163895] [ INFO: suspicious RCU usage. ]
> [    3.163897] 3.9.0-rc3-next-20130322-dbg-dirty #1 Not tainted
> [    3.163898] -------------------------------
> [    3.163900] fs/eventpoll.c:545 suspicious rcu_dereference_check() usage!

Sorry about this, I've fixed this and it is in the latest -mm

http://mid.gmane.org/20130321192748.6D86F31C23C@corp2gmr1-1.hot.corp.google.com

Re: [-next] fs/eventpoll.c:545 suspicious rcu_dereference_check() usage

[Sergey Senozhatsky]

On (03/23/13 17:34), Eric Wong wrote:
> Sergey Senozhatsky <sergey.senozhatsky@gmail.com> wrote:
> > [    3.163894] ===============================
> > [    3.163895] [ INFO: suspicious RCU usage. ]
> > [    3.163897] 3.9.0-rc3-next-20130322-dbg-dirty #1 Not tainted
> > [    3.163898] -------------------------------
> > [    3.163900] fs/eventpoll.c:545 suspicious rcu_dereference_check() usage!
> 
> Sorry about this, I've fixed this and it is in the latest -mm
> 
> http://mid.gmane.org/20130321192748.6D86F31C23C@corp2gmr1-1.hot.corp.google.com
> 

thanks a lot.

	-ss