Re: (maybe) crash your VAX from userspace

I hope there is someone with a Qbus VAX up and running. I have one in 
storage where I live which I could eventually drag up, but won't happen 
in the very near future...

   Johnny

On 2024-03-23 01:37, Alexander Schreiber wrote:
> Hi,
> 
> do you have a real metal VAX? Do you run NetBSD 10.0 RC6 on it? Are
> you ok with (maybe) crashing it? Then you are the person I'm looking
> for (maybe)!
> 
> While I was investigating network-activity related SIMH/vax crashes
> (as in: the simulator segfaulted), I tried to test with smaller MTU
> size to check a theory. So I ran "ifconfig qe0 mtu 512" ... at which
> point I got this:
> 
> ifconfig qe0 mtu 512
> [ 459.2554210] r0=87fd9028 r1=00000000 r2=00000000 r3=87a2e500 r4=80692f34 r5=00000000 r6=87fd9028 r7=87e91b80
> [ 459.2554210] r8=00000000 r9=87e91b80 r10=8090697f r11=00000000
> [ 459.2554210] ap=8b869c7c fp=8b869c68 sp=7ffff50c pc=80259431
> [ 459.2554210] panic: SEGV in kernel mode: pc 0x80259431 addr 0
> [ 459.2554210] cpu0: Begin traceback...
> [ 459.2554210] panic: SEGV in kernel mode: pc 0x80259431 addr 0
> [ 459.2554210] Stack traceback :
> [ 459.2554210]   Process is executing in user space.
> [ 459.2554210] cpu0: End traceback...
>   
> [ 459.2554210] dump to dev 9,1 not possible
>   
> HALT instruction, PC: 80013565 (PUSHAB 802A2F6B)
> Goodbye
> 
> I _suspect_ this is a driver specific issue. So we need:
>   - a real metal VAX
>   - that has the qe ethernet device
>   - that runs NetBSD 10.0 RC6
>   - that you are ok with crashing
> 
> Your mission, if you choose to accept it, is to run "ifconfig qe0 mtu 512"
> on your VAX and report back what happens. Three likely outcomes:
>   - ifconfig tells you to bugger off (happened with NetBSD 5.0.2 where
>     I got "ifconfig: SIOCSIFMTU: Invalid argument"
>   - it works and then the kernel complains about oversized frames
>     (behaviour on 9.3 with sparc64) which is Working As Expected
>   - you get a kernel crash
> 
> If you don't run 10.0 RC6, I've reproduced this as far back as 8.0
> and I've got a PR primed to go, but before I file it, I want to make
> sure this actually also happens on real hardware and is not a weird
> simulator edge case. If it doesn't happen on real hardware, well,
> then I've got a different tree to bark up to ...
> 
> Bold volunteers wanted!
> 
> Kind regards,
>            Alex.

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: [email protected]             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol