[Info-vax] RMS and SSIO (again)

[Simon Clubley]

On 2022-01-10, Greg Tinkler <tinklerg at gmail.com> wrote:
>
> Simon
> re "how something was done 30 years ago", you are correct, some people
> like you seem to believe 2 mode OS's are the go, not 4 mode.  The research
> was done 50 years ago and the outcome was 4 mode.  And which advancements? 
> Things have got bigger and faster but the underlying architecture is still
> based on work done in WWII which is before I was born.
>

>From a security point of view, VMS is a 2-mode operating system, not a
4-mode operating system. Once you are in one of the inner modes, you
can get to any of the other two inner modes without needing any additional
account privileges.

And BTW, the most secure design these days is the microkernel design
because that design isolates components that would normally be in a
monolithic kernel from each other and also gives them restricted
access rights and privileges. Those designs run just fine on a 2-mode
hardware architecture.

> Yes there is a performance cost, there always is for security.  NB most
> *nix now have lots of code in kernel just checking for possible hacks...
>

Having all the ASLR/KASLR/mandatory access control security in Linux is
a very good thing and it should be present in VMS as well.

The fact you seem to think this is a bad thing tells me you really
are living in the past.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.