kern/55151: atf-run in tests/lib/libc/sys/ crashes kernel

[martin%NetBSD.org@localhost]

>Number:         55151
>Category:       kern
>Synopsis:       atf-run in tests/lib/libc/sys/ crashes kernel
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Apr 07 15:35:00 +0000 2020
>Originator:     Martin Husemann
>Release:        NetBSD 9.99.55
>Organization:
The NetBSD foundation, Inc.
>Environment:
System: NetBSD space-truckin.duskware.de 9.99.55 NetBSD 9.99.55 (GENERIC) #66: Tue Apr 7 12:21:00 CEST 2020 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/evbarm/compile/GENERIC evbarm
Architecture: earmv7hfeb
Machine: evbarm
>Description:

Running atf tests crashes all my -current systems most of the time.
This instance stopped outputing the atf log like this:

    traceme_lwpnext1: [0.127321s] Passed.
    traceme_lwpnext1_pl_name: [0.127963s] Passed.
    traceme_lwpnext1_pl_private: [0.128292s] Passed.
    traceme_lwpnext1_pl_sigmask: [0.108298s] Passed.
    traceme_lwpnext2: [0.278676s] Passed.
    traceme_lwpnext2_pl_name: [0.138638s] Passed.
    traceme_lwpnext2_pl_private: [0.158479s] Passed.
    traceme_lwpnext2_pl_sigmask: [0.308651s] Passed.
    traceme_lwpnext3: [0.448700s] Passed.
    traceme_lwpnext3_pl_name: [0.238520s] Passed.
    traceme_lwpnext3_pl_private: [0.308404s] Passed.
    traceme_lwpnext3_pl_sigmask: [0.448537s] Passed.
    traceme_pid1_parent: [0.100761s] Passed.
    traceme_raise1: [0.098255s] Passed.
    traceme_raise10: 

Crash version 9.99.55, image version 9.99.55.
crash: _kvm_kvatop(0)
Kernel compiled without options LOCKDEBUG.
System panicked: kernel diagnostic assertion "(code != TRAP_CHLD) || (entity > 1)" failed: file "../../../../kern/kern_sig.c", line 1600 

No backtrace, gdb does not like the core at all.

>How-To-Repeat:
cd /usr/tests/lib/libc/sys && atf-run

>Fix:
n/a