kern/56479: Crash in ata_recovery_resume

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

>Number:         56479
>Category:       kern
>Synopsis:       Crash in ata_recovery_resume
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Oct 31 08:25:00 +0000 2021
>Originator:     Andreas Gustafsson
>Release:        NetBSD 9.2
>Organization:
  
>Environment:
System: NetBSD guido.araneus.fi 9.2
Architecture: x86_64
Machine: amd64
>Description:

My Dell PowerEdge R630 server running NetBSD/amd64 9.2 crashed
overnight:

  guido /var/crash # gdb /netbsd
  [...]
  Reading symbols from /netbsd...
  (No debugging symbols found in /netbsd)
  (gdb) target kvm netbsd.4.core
  0xffffffff80222aaa in cpu_reboot ()
  (gdb) bt
  #0  0xffffffff80222aaa in cpu_reboot ()
  #1  0xffffffff80994a96 in vpanic ()
  #2  0xffffffff80994b47 in panic ()
  #3  0xffffffff80224aed in trap ()
  #4  0xffffffff8021d56b in alltraps ()
  #5  0xffffffff8027bd27 in ata_recovery_resume ()
  #6  0xffffffff80279912 in ata_thread_run ()
  #7  0xffffffff8027a236 in atabus_thread ()
  #8  0xffffffff80209747 in lwp_trampoline ()
  #9  0x0000000000000000 in ?? ()
  (gdb) frame 5
  #5  0xffffffff8027bd27 in ata_recovery_resume ()
  (gdb) x/i $pc
  => 0xffffffff8027bd27 <ata_recovery_resume+245>:    movzwl 0x10(%rax),%edx
  (gdb) print $rax
  $1 = 0

No debug symbols because PR 55557.

>How-To-Repeat:

>Fix: