Re: sctp: hang in sctp_remaddr_seq_show

2013-03-18 Thread Eric Dumazet
On Mon, 2013-03-18 at 16:32 -0400, Neil Horman wrote: > Vlads, right. We need to grab the rcu lock before the read lock, but we > should > probably use the rcu_read_lock_bh variant, since we're going to disable bottom > halves anyway. > Neil rcu_read_lock_bh() and {local_bh_disable();rcu_read_l

Re: sctp: hang in sctp_remaddr_seq_show

2013-03-18 Thread Vlad Yasevich
On 03/18/2013 04:32 PM, Neil Horman wrote: On Mon, Mar 18, 2013 at 11:31:06AM -0400, Vlad Yasevich wrote: On 03/18/2013 11:25 AM, Eric Dumazet wrote: On Mon, 2013-03-18 at 07:04 -0400, Neil Horman wrote: I'm not sure why the process would never get back to the schedule, but looking at the sct

Re: sctp: hang in sctp_remaddr_seq_show

2013-03-18 Thread Neil Horman
On Mon, Mar 18, 2013 at 11:31:06AM -0400, Vlad Yasevich wrote: > On 03/18/2013 11:25 AM, Eric Dumazet wrote: > >On Mon, 2013-03-18 at 07:04 -0400, Neil Horman wrote: > > > >>I'm not sure why the process would never get back to the schedule, but > >>looking > >>at the sctp_remaddr_seq_show function

Re: sctp: hang in sctp_remaddr_seq_show

2013-03-18 Thread Vlad Yasevich
On 03/18/2013 11:25 AM, Eric Dumazet wrote: On Mon, 2013-03-18 at 07:04 -0400, Neil Horman wrote: I'm not sure why the process would never get back to the schedule, but looking at the sctp_remaddr_seq_show function, I think that we should convert this sequence: sctp_local_bh_disable();

Re: sctp: hang in sctp_remaddr_seq_show

2013-03-18 Thread Eric Dumazet
On Mon, 2013-03-18 at 07:04 -0400, Neil Horman wrote: > I'm not sure why the process would never get back to the schedule, but looking > at the sctp_remaddr_seq_show function, I think that we should convert this > sequence: > sctp_local_bh_disable(); > read_lock(&head->lock); > r

Re: sctp: hang in sctp_remaddr_seq_show

2013-03-18 Thread Neil Horman
On Fri, Mar 15, 2013 at 12:34:00PM -0400, Sasha Levin wrote: > Hi all, > > While fuzzing with trinity inside a KVM tools guest running latest -next > kernel, > I've stumbled on an interesting hang related to sctp. > > After some fuzzing, I get a hang message about procfs not able to grab a hold

sctp: hang in sctp_remaddr_seq_show

2013-03-15 Thread Sasha Levin
Hi all, While fuzzing with trinity inside a KVM tools guest running latest -next kernel, I've stumbled on an interesting hang related to sctp. After some fuzzing, I get a hang message about procfs not able to grab a hold of a mutex for one of the files: [ 375.900309] INFO: task trinity-child21: