kern/56819: netbsd32 compat does not handle sign-extended addresses

[mlelstv%netbsd.org@localhost]

>Number:         56819
>Category:       kern
>Synopsis:       netbsd32 compat does not handle sign-extended addresses
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat May 07 11:10:00 +0000 2022
>Originator:     Michael van Elst
>Release:        NetBSD 9.2_STABLE
>Organization:
	
>Environment:
	
	
System: NetBSD victory.netbsd.org 9.2_STABLE NetBSD 9.2_STABLE (GENERIC64) #16: Fri Jan 21 02:56:58 CET 2022 mlelstv@gossam:/home/netbsd9/obj.evbarm64-el/home/netbsd9/src/sys/arch/evbarm/compile/GENERIC64 evbarm
Architecture: aarch64
Machine: evbarm
>Description:

32bit programs running on a 64bit aarch system may generate warnings like:

netbsd32_mmap: retval out of range: 0xffffffffff546000

The resulting address is compared against 32bit unsigned int to
produce that warning message, the truncated value is still returned
to userland.

-current prints the message only when mmap returned success. So
these could be junk return values from a failed mmap in netbsd-9.

>How-To-Repeat:

Run a 32bit program on aarch64 that calls mmap and gets a mapping
beyond 2GB.

>Fix:
	

>Unformatted: