Why does the S5 init run "/bin/su" in single-user mode

[Mats Wichmann]

> 	One reason I might do such a thing is to prevent passers-by from
> booting the system and getting a root shell. 

But...., but....???

When rebooting, the system runs as superuser, so the `su' to `root' will
always succeed - without asking for a password - so you get a superuser
shell anyway. How does this make things any more secure?

Incidentally, speaking of the S5 init, how many of you out there were
aware of a neato init state executed BEFORE anything else is brought
up, activated by the tag `sysinit' in your inittab? This one is
real handy if there are commands that MUST be done before you even get
a single-user shell - perhaps initializing some sort of user device or
checking the root file system. I found this in the code while trying to
solve a problem for someone here; turns out it exactly solved the problem -
but I have not seen it documented anywhere (!surprise!).

	    Mats Wichmann
	    Dual Systems Corp.
	    ...{ucbvax,amd70,ihnp4,cbosgd,decwrl,fortune}!dual!mats