kern/58801: magic symlinks do not work for COMPAT_NETBSD32

[martin%NetBSD.org@localhost]

>Number:         58801
>Category:       kern
>Synopsis:       magic symlinks do not work for COMPAT_NETBSD32
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Nov 01 07:25:00 +0000 2024
>Originator:     Martin Husemann
>Release:        NetBSD 10.99.12
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD night-owl.duskware.de 10.99.12 NetBSD 10.99.12 (NIGHT-OWL) #2: Thu Oct 24 08:03:58 CEST 2024 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/amd64/compile/NIGHT-OWL amd64
Architecture: x86_64
Machine: amd64
>Description:

Magic symlinks (sysctl vfs.generic.magiclinks=1) do not work properly with
COMPAT_NETBSD32 binaries. The tests for @machine and @machine_arch fail.
This is not trivialy fixable as it is pretty much unclear what string the
emulation should use for that replacement, expecially in cases where
we have lots of userland variation like evbarm. E.g. a kernel compiled
for evbearmv7hf-el can execute userland compiled for evbearmv5 or
evbearmv6hf-el just fine - so what string should an aarch64 kernel use?

Fixing the amd64/i386 and sparc64&/sparc case shoule be relatively simple.

>How-To-Repeat:

install i386 or evbearmv* userland on amd64 or aarch64, chroot to it
and the do

	cd /usr/tests/ kernel && atf-run t_magic_symlinks

>Fix:
n/a