kern/49530: kernel crash with corrupt stack/invalid backtrace

[martin%NetBSD.org@localhost]

>Number:         49530
>Category:       kern
>Synopsis:       kernel crash with corrupt stack/invalid backtrace
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jan 03 14:15:00 +0000 2015
>Originator:     Martin Husemann
>Release:        NetBSD 7.99.4
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD thirdstage.duskware.de 7.99.4 NetBSD 7.99.4 (MODULAR) #243: Fri Jan 2 18:46:49 CET 2015 martin%thirdstage.duskware.de@localhost:/usr/src/sys/arch/sparc64/compile/MODULAR sparc64
Architecture: sparc64
Machine: sparc64
>Description:

I got this twice after updating my machine recently - once sometime over night
(probably during the nightly runs, machine was otherwise idle), the last time
during a "cvs up" (otherwise idle).

The machine drops into ddb, but stack backtrace on both CPUs is empty.
The register window dump however is interesting:

text_access_fault: pc=0 va=0
kernel trap 64: +fast instruction access MMU miss
Stopped in pid 0.9 (system) at  0:      undefined
db{0}> mach stack                                
Window 0 frame64 0x1b027ba80 locals, ins:
103af9660 2ac8 0 0 17e73a0 17ac220 17ac1e8 17bf678
1052fb8f0 20002 10 4 104754008 1749ee0 1b027b351=sp 156d73c=pc:netbsd:vn_lock+0x7c
Window 1 frame64 0x1b027bb50 locals, ins:
18310f0 17ac1e8 17ac220 17ac220 1816908 17ac220 17ac1e8 2014000
1052fb8f0 20002 103b558e0 1ce4000 104754008 0 1b027b401=sp 1569624=pc:netbsd:vclean+0x84
Window 2 frame64 0x1b027bc00 locals, ins:
0 1c16400 1c98000 1 4 17ba020 0 6        
1052fb8f0 103b558e0 103b558e0 0 103b558e0 1 1b027b4c1=sp 156ad1c=pc:netbsd:cleanvnode+0x13c
Window 3 frame64 0x1b027bcc0 locals, ins:
17ac220 17ac1e8 1831558 18313d8 0 17ac220 17ac1e8 17bf678
0 1831288 1c95400 1c95580 1c95580 1052fb8f0 1b027b571=sp 156aee4=pc:netbsd:vdrain_thread+0x84
Window 4 frame64 0x1b027bd70 locals, ins:
103b44420 1b0278000 deaddead 1b027bed0 1c6f868 1b0270000 e0048000 e0048000
1c95500 1831598 1c0a154 1c95600 1c0a140 1c955c0 1b027b621=sp 1011fb8=pc:netbsd:lwp_trampoline+0x8
Window 5 frame64 0x1b027be20 locals, ins:
156ae60 103b558e0 103b558e0 1fff 28 30 3 2014000
f005eab8 113668 116000 1 0 fedc9c48 fedc9651=sp 100950=pc:100950
Window 6 frame64 0xfedc9e50 locals, ins:                        
fff72020 10f8 0 f0068080 10000 1001f59e0 0 7fff001927c
0 0 0 0 f005eab8 0 fedc9701=sp 0=pc:0                 
Window 7 frame64 0xfedc9f00 locals, ins:
0 0 0 0 0 0 0 0                         
0 0 0 0 0 0 0=sp 0=pc:0



>How-To-Repeat:
n/a

>Fix:
n/a