port-sparc/57623: pv_flushcache4m called with bogus vm_page

[martin%NetBSD.org@localhost]

>Number:         57623
>Category:       port-sparc
>Synopsis:       pv_flushcache4m called with bogus vm_page
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-sparc-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Sep 20 16:55:00 +0000 2023
>Originator:     Martin Husemann
>Release:        NetBSD 10.99.8
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD sunset-glow.duskware.de 10.99.8 NetBSD 10.99.8 (GENERIC.MP) #42: Wed Sep 20 14:51:56 CEST 2023 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/sparc/compile/GENERIC.MP sparc
Architecture: sparc
Machine: sparc
>Description:

While doing pkg builds I repeatadly got a crash due to a bogus vm_page
passed to pv_flushcache4m: 0xdeaddead

[ 5595.7889865] memfault_sun4m(0xf059e1d8, 0xf0008de0, 0xf423f, 0xf059e138, 0xa0, 0x2) at netbsd:pv_flushcache4m+0x5c
[ 5595.8813861] pv_flushcache4m(0xdeaddead, 0x1, 0xf1f7c6c0, 0xf04b9000, 0x0, 0xf0002000) at netbsd:pmap_copy_page4m+0x198
[ 5595.9529349] pmap_copy_page4m(0x116400, 0x8e4a000, 0x0, 0x1, 0x0, 0xf1f7c6c0) at netbsd:uvm_pagecopy+0x34
[ 5596.0210570] uvm_pagecopy(0xf07a7650, 0xf0a17e30, 0xedec1000, 0xf0038dc4, 0xff000000, 0xedec1000) at netbsd:uvmfault_promote+0x190
[ 5596.1190399] uvmfault_promote(0xfb771da4, 0x0, 0xf0a17e30, 0xfb771da0, 0xfb771dd8, 0xf21d57f0) at netbsd:uvm_fault_internal+0x13e0
[ 5596.2190214] uvm_fault_internal(0xf04b4098, 0xf04b40a8, 0x1, 0xf2260300, 0xf07a7650, 0xf05b2e64) at netbsd:mem_access_fault4m+0x2ec
[ 5596.2992827] mem_access_fault4m(0x9, 0x386, 0xedec0794, 0xfb771fb0, 0xf14608c0, 0xf1f7c6c0) at netbsd:memfault_sun4m+0xec
[ 5596.3819842] cpu0: End traceback...

This is on a dual SS20.

>How-To-Repeat:
s/a

>Fix:
n/a