On 7/08/2014 7:49 PM, Ryota Ozaki wrote:
> Hi,
>
> I thought I need more experience of pserialize
> (and lock primitives) to tackle ifnet work.
> So I suspended the work and now I am trying
> another easier task, bpf.
>
> http://www.netbsd.org/~ozaki-r/mpsafe-bpf.diff
>
This code has race conditions built into it where locks are
dropped for others to be acquiredwith no knowledge stored
anywhere that a critical section of code is being executed:
+ mutex_exit(d->bd_lock);
+ KERNEL_LOCK(1, NULL);
What you need here is a perimeter mechanism that doesn't
hold any locks over the inner section of code.
This needs to be fixed:
error = tsleep(d, PRINET|PCATCH, "bpf", d->bd_rtout);
- it should actually be a cv_timedwait_sig() on bd_lock.
Darren
