mq_send()/mq_receive() may never return if used from threads

Mon Jan 27 19:35:11 GMT 2025

On Jan 27 19:59, Christian Franke via Cygwin wrote:
> Christian Franke wrote:
> > Found with 'stress-ng --workload ...':
> > 
> > If mq_receive is called on an empty queue and mq_send is called later
> > from a different thread, both functions never return and signals
> > (including SIGKILL) are no longer processed.
> > 
> > Testcase (attached):
> > 
> > $ uname -r
> > 3.5.5-1.x86_64
> > 
>> The problem is also reproducible with 3.5.6-1 and recent
> 3.6.0-0.345.gb940faa144ca

Yes, because I didn't have the time to look into it yet.
I just did, and I think I see what's going on. This should be fixed
in 3.5.7.
Corinna