GENERIC_SUN4U kernel trap 30: data access exception

Hello,
on a netra box running a 32bit GENERIC_SUN4U kernel (this is the reason
for the cross-post :) NetBSD 7.0, I just got:
login: cpu0: data fault: pc=141320c rpc=620401032123a47 addr=0
kernel trap 30: data access exception
Stopped in pid 21062.1 (cc1plus) at     netbsd:pmap_remove_pv+0x6c:     ld              [
%i0 + %g0], %g3
db{0}> 
db{0}> tr
pmap_remove(4c76040, fdece000, fdfe0000, 1caf658, 0, 17cce000) at netbsd:pmap_re
move+0xd8
uvm_unmap_remove(3d80af8, 1e0000, 7481f78, 32123b74, 0, 7480e48) at netbsd:uvm_u
nmap_remove+0x114
uvmspace_free(3d80af8, 4ea5090, ffffffff, 1c65c80, 0, 3d80b04) at netbsd:uvmspac
e_free+0xc0
exit1(4ac5a80, 86, 1c9c400, 1c82400, 32123bd8, 424f0f0) at netbsd:exit1+0x154
sigexit(4ac5a80, 86, 424f0f0, 180000, 86, 0) at netbsd:sigexit+0x13c
postsig(6, 0, 424f0f0, 4ac5c14, 32123cd8, 4ac5a80) at netbsd:postsig+0xd4
lwp_userret(4ac5a80, 1000000, 20000, 100000, 91a0002, 424f0f0) at netbsd:lwp_use
rret+0x164
syscall(32123ed0, 32123f50, ff7ded7c, 4ac5a80, 0, 424f0f0) at netbsd:syscall+0x1
38
?(1, 6, 0, ff7dcce8, 2, 0) at 1010d40
db{0}> 

This system was rock solid when running netbsd-5 ...

-- 
Manuel Bouyer <[email protected]>
     NetBSD: 26 ans d'experience feront toujours la difference
--