[Info-vax] How dangerous is it to be able to get into DCL supervisor mode ?

[David Froble]

VAXman- @SendSpamHere.ORG wrote:
> In article <ojegsn$kf$1 at dont-email.me>, Simon Clubley <clubley at remove_me.eisner.decus.org-Earth.UFP> writes:
>> On 2017-07-03, VAXman-  @SendSpamHere.ORG <VAXman- at SendSpamHere.ORG> wrote:
>>> When in exec mode, one can invoke $CMKRNL and execute code in kernel
>>> mode without possessing the privies needed for $CMKRNL because there
>>> is a check for the previous mode being exec.  There's nothing similar
>>> for $CMEXEC from supervisor mode.  It sure would have removed a few
>>> hurdles for me when writing my DCL Debugger had that been the case.
>>>
>> Thanks Brian.
>>
>> There's still the bit about being able to set the privilege bits
>> in supervisor mode however.
>>
>> However, if supervisor mode lets you do that, then that would seem to
>> defeat the whole point of actually _having_ a supervisor mode. :-)
> 
> Because I'm already in supervisor mode with the debugger, I'll check on
> this but I have some other issues that I need to focus on first.  Also,
> it's US In-Dependence Day here.
> 

What do you do in the DCL debugger when the image is interrupted?  Such as 
CTRL-Y?  I'm going to assume that you don't leave the process in supervisor mode?

Which causes me to be curious.  What happens after CTRL-Y and then "CONTINUE"?