kern/60216: VM_MAXUSER_ADDRESS and VM_MAX_ADDRESS both exist, and that is dumb

["thorpej%me.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60216
>Category:       kern
>Synopsis:       VM_MAXUSER_ADDRESS and VM_MAX_ADDRESS both exist, and that is dumb
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Wed Apr 29 13:20:00 +0000 2026
>Originator:     Jason Thorpe
>Release:        NetBSD 11 (and 10, and 9, and 8, and ...)
>Organization:
Society for Aspiring Unix Grey-beards
>Environment:
NetBSD virt68k 11.99.5 NetBSD 11.99.5 (GENERIC) #195: Tue Apr 28 20:50:18 PDT 2026  thorpej@dhcp-194.ktnet:/Users/thorpej/NetBSD/current/src/sys/arch/virt68k/compile/GENERIC virt68k

>Description:
There are two constants in <machine/vmparam.h> that both basically describe the same thing:

#define VM_MAXUSER_ADDRESS      ((vaddr_t)(USRSTACK))
#define VM_MAX_ADDRESS          ((vaddr_t)(0-(UPAGES*PAGE_SIZE)))

There is absolutely no need for this, and it is probably a remnant of the "u." era, which we stopped living in literally decades ago.
>How-To-Repeat:
Look in <machine/vmparam.h>.
>Fix:
VM_MAXUSER_ADDRESS should be garbage-collected.