port-evbmips/59236: Multiple segfaults in erlite3 boot

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         59236
>Category:       port-evbmips
>Synopsis:       Multiple segfaults in erlite3 boot
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-evbmips-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 30 09:15:00 +0000 2025
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current, source date 2025.03.29.19.40.42
>Organization:
  
>Environment:
System: NetBSD
Architecture: evbmips
Machine: mips64eb
>Description:

I tried to install NetBSD-current on a Ubiquity EdgeRouter Lite aka
ERLite-3 by building a evbmips-mips64eb release (without debug
symbols because PR 59233), uncompressing octeon.img.gz, dd:ing it
onto on a USB flash drive, plugging the drive into the internal
USB connector, and using the u-boot configuration from
https://www.cambus.net/netbsd-on-the-edgerouter-lite/.

During the initial boot, ps dumped core:

  [   1.7995905] WARNING: CHECK AND RESET THE DATE!
  Sat Mar 29 19:40:42 UTC 2025
  [1]   Segmentation fault      /bin/sh -c "ps -p \$\$ -o ppid="
  Starting root file system check:

The system nonetheless managed to resize the root partition and
reboot, but during the second boot, there were further segfaults
from ps, mount, and fsck:

  [   6.6503459] WARNING: CHECK AND RESET THE DATE!
  Sat Mar 29 19:40:44 UTC 2025
  [1]   Segmentation fault      /bin/sh -c "ps -p \$\$ -o ppid="
  Starting root file system check:
  /dev/rdk1: file system is clean; not checking
  Not resizing / (NAME=octeon-root): already correct size
  mount: /: Segmentation fault
  Setting sysctl variables:
  ddb.onpanic: 1 -> 0
  Starting file system checks:
  [1]   Segmentation fault      fsck -x / ${fsck_flags}
  Unknown error 139; help!
  ERROR: ABORTING BOOT (sending SIGTERM to parent)!
  init: `/bin/sh' Enter pathname of shell or RETURN for /bin/sh: 

A full console log is at

  https://www.gson.org/netbsd/bugs/erlite3/erlite3-2025.03.29.19.40.42-boot.txt

A system built from CVS source date 2025.01.01.00.00.05 does not have
this problem.  Perhaps it is related to the mipsn64 problem reported in

  https://mail-index.netbsd.org/port-mips/2025/02/03/msg001435.html

>How-To-Repeat:

>Fix: