re: kern/44418 (FAST_IPSEC and if_wm kernel panic - may affect the whole network stack)

[matthew green <mrg%eterna.com.au@localhost>]

> rmind%netbsd.org@localhost said:
> > Not sure what do you mean by "second time"
> > [...]
> > Recursive locking is
> > deliberately prohibited in our mutex(9) implementation
> > [...]
> > Talking about limited softintr thread context
> 
> What I did suspect here is that some kernel code takes softnet_lock
> without a splsoftnet() before, and a softnet handler gets to run
> and happens to borrow the same thread context. In that case,
> the diagnostic check could fire even if the softnet handler
> doesn't do anything wrong.
> Can this happen?

in sparc smp land, where we've only recently started being stable
again, the last 2 crashes i've seen were softnet_lock issues.
i don't have the details handy, but it invovled slowtimo processing
and softnet_lock being re-taken on the same CPU.

i've wondered the same thing r.e. splsoftnet.


.mrg.