[TUHS] Unix use of VAX protection modes

[Paul Winalski via TUHS]

The discussion of the history of virtual addressing in Unix called to my
mind a related question:

The VAX has four protection modes, from lowest to highest in privilege:
user, supervisor, executive, kernel.  Access to certain instructions and
hardware data structures can only be done from kernel mode.  User mode is
of course intended for use by non-privileged code and data.  The VAX/VMS
Digital Command Language (DCL) command interpreter ran in supervisor mode.
Record Management Services (RMS, the primary way to access disk files) ran
in executive mode.  The kernel, device drivers, hardware interrupt
handlers, etc. ran in kernel mode.

Obviously Unix user-mode process code and data ran in user mode.  Likewise
the parts of the kernel that had to access privileged bits of the hardware
(such as device drivers) must have run in kernel mode.

My question is, did Unix make any use of either supervisor or executive
mode on the VAX?

-Paul W.