[HECnet] Call for help to debug RTPAD.EXE on OpenVMS V8.3

[Cory Smelosky]

On Mon, 20 May 2013, Brian Schenkenberger, VAXman- wrote:


G. <gerry77 at mail.com> writes:

Hello all!

Let's try to summarize the problem.

RTPAD.EXE is the executable image behind SET HOST and SET HOST/APP=3DR on=
VMS,
and it can use both CTERM and RTERM protocols to connect to remote =
systems.

Some older OSes, notably TOPS-10 and RSTS (and others, I suppose), do =
either
behave badly when accessed with the newer CTERM protocol, mainly because =
it's
too VMS-centric, or do not work at all because they do not suppport it. =
To
connect to them, the solution is to always use the older RTERM protocol.

RTPAD.EXE on OpenVMS V8.3 for both Alpha and Itanium (IIRC) has some =
serious
bug that prevents it from connecting to such older OSes using the old =
RTERM
protocol: actually it ACCVIOs before doing any useful work.

The RTERM protocol can be used to connect to VMS too, and when connecting=
to
another VMS node using RTERM, the V8.3 RTPAD.EXE works as expected. So, =
either
some older OSes are sending out-of-standard packets (and the older =
RTPAD.EXE
were more forgiving), or the new RTPAD.EXE cannot understand all the =
protocol
variants and intricacies (as the older versions did).

I tried exchanging V8.3 RTPAD.EXE (ident X-10) with a couple of older =
versions
(idents X-8, X-9) and even with the V8.4 one (ident X-10 too, so should =
be the
same as V8.3), to no avail: every one of them ACCVIOs as well. The oldest=
I
tried (X-8) comes from plain vanilla V7.2 (and does not work), but I'm =
almost
sure (I cannot swear on it, though) that RTERM worked fine in V7.2, so =
I'm
stuck: the same image (X-8) was working on V7.2 but it's not in V8.3.

I know that testing by exchanging images among different VMS versions is =
not
bulletproof, but considering that I didn't get any error like SHRIDMISMAT=
and
such, I feel confident about thinking that they are compatible. So maybe =
the
problem is somewhere else, probably in some shared library.

What else can I do? Is there anyone with the right knowledge (I'm =
thinking to
e.g. Brian Schenkenberger) that can try to track down the bug and at =
least
identify in which part of VMS lies the problem? Or give me some =
suggestions...

This is what happens:

| $ set host/app=3Dr xxxxxx
| %REM-I-CONNECTION, connection made using RTERM protocol
|=A0%SYSTEM-F-ACCVIO,=A0access=A0violation,=A0reason=A0mask=3D00,=A0virtu=
al=A0address=3D000052D800008AA4,=A0PC=3D000052D800008AA4,=A0PS=3D0000001B
|=20
|     Improperly handled condition, image exit forced.
|         Signal arguments:     Number =3D 0000000000000005
|                                                 Name     =3D 000000000000000C
|                                                                   0000000000010000
|                                                                   000052D800008AA4
------------------------------------^v^v^v^v^v^v^v^v
|                                                                   000052D800008AA4
|                                                                   000000000000001B

This looks bad.   I can tell you that it's not very likely a problem VMS address
which RTPAD is operating in.   I suspect that 0000000000008AA4 would be close to
the PC in the RTPAD image or 0000000000052D8.   I would guess that some improper
stack manipulation is the cause for this error.

If this stack dump came from V8.3, I'll take a look in the source to see if the
addresses yield anything.   Please confirm that the above was from the Alpha V8.3
RTPAD.
-- 
VAXman- A Bored Certified VMS Kernel Mode Hacker       VAXman(at)TMESIS(dot)ORG

Well I speak to machines with the voice of humanity.


I was going to grab the stack dump from 8.4...but there's a completely different issue there.
$ set host/app=rterm marley
%SYSTEM-F-UNREACHABLE, remote node is not currently reachable
$ set host marley
*INTERRUPT*

$
$ set host/lat marley
%LAT-S-CONNECTED, session to MARLEY established

Can anyone else reach MARLEY?   DECnet is up...I cam reach it from 7.2 on simh and my area router can ping it.

--
Cory Smelosky
http://gewt.net/ Personal stuff
http://gimme-sympathy.org Experiments