[lttng-dev] baddr feature triggers deadlock in lttng-ust

[Woegerer, Paul]

I have looked a bit into the issue...

The ust_locking inside the dl_iterate_phdr triggers the deadlock.

If I just collect the base address info inside dl_iterate_phdr and dump
the collected data with trace_baddr afterwards (outside the
dl_iterate_phdr iteration) the deadlock will be prevented.

I'm now going to create a patch that implements this approach.

Thanks,
Paul

On 02/27/2014 10:30 PM, Mathieu Desnoyers wrote:
> Hi Paul,
>
> Please see http://bugs.lttng.org/issues/745, which explains a deadlock
> we just found out.
>
> We might have to disable the baddr dump feature, since our release is
> tomorrow. We'll have to re-think our locking to protect operations
> using the dynamic loader lock against fork, clone, and daemon.
>
> Thanks,
>
> Mathieu
>


-- 
Paul Woegerer, SW Development Engineer
Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer>
Mentor Graphics, Embedded Software Division