Re: NetBSD xen dom0 kernel panic

[Frank de Bot <netbsd%searchy.net@localhost>]

Christos Zoulas wrote:
> On Mar 17,  1:54pm, netbsd%searchy.net@localhost (Frank) wrote:
> -- Subject: Re: NetBSD xen dom0 kernel panic
>
> | Christos Zoulas wrote:
> | > In article <49BF92B2.7020005%searchy.net@localhost>, Frank  
> <netbsd%searchy.net@localhost> wrote:
> | >   
> | >> A few times my test NetBSD server running NetBSD 5.0_RC2 (amd64) 
> | >> suddenly crashed. (every 2-3 days)
> | >>
> | >> At the moment of the crash dmesg is:
> | >>
> | >>     
> | >
> | > A LOCKDEBUG kernel will give you more information.
> | >
> | > christos
> | >
> | >   
> | Ok, I'll build a kernel with that option. Are there any other things 
> | which could be helpfull on debugging this?
>
> I usually build testing kernels with DIAGNOSTIC+DEBUG+LOCKDEBUG. I think
> that the problem you are seeing is a recursive lock that would result in
> deadlock (or unlocking and unlocked lock). The LOCKDEBUG kernel should
> point out where the lock is currently held from (or where it was last
> held and released). There are ddb commands to examine the locks, but
> I don't remember them off hand right now.
>
> christos
>   

I booted up a kernel with the LOCKDEBUG option on. It paniced during 
boot. Output:

Mutex error: lockdebug_wantlock: acquiring sleep lock from interrupt context

lock address : 0xffffffff80b20130 type     :     sleep/adaptive
initialized  : 0xffffffff8043c60b
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  0
current cpu  :                  0 last held:                  0
current lwp  : 0xffffa0002a3cbba0 last held: 000000000000000000
last locked  : 0xffffffff8043b4ef unlocked : 0xffffffff8043b78c
owner field  : 000000000000000000 wait/spin:                0/0

Turnstile chain at 0xffffffff80b3c2c0.
=> No active turnstile for this lock.

panic: LOCKDEBUG
fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff804d64cd cs e030 rflags 246 cr2  
7f7fffffcff8 cpl 6 rsp ffffa0002a403158
Stopped in pid 334.1 (arp) at   netbsd:breakpoint+0x5:  leave
breakpoint() at netbsd:breakpoint+0x5
panic() at netbsd:panic+0x242
lockdebug_abort1() at netbsd:lockdebug_abort1+0xd3
mutex_vector_enter() at netbsd:mutex_vector_enter+0x17f
pool_get() at netbsd:pool_get+0x4f
pf_test_rule() at netbsd:pf_test_rule+0xaf9
pf_test() at netbsd:pf_test+0xc96
pfil4_wrapper() at netbsd:pfil4_wrapper+0x57
pfil_run_hooks() at netbsd:pfil_run_hooks+0xa0
bridge_ipf() at netbsd:bridge_ipf+0x239
pfil_run_hooks() at netbsd:pfil_run_hooks+0xa0
bridge_forward() at netbsd:bridge_forward+0xbd
bridge_input() at netbsd:bridge_input+0x14b
ether_input() at netbsd:ether_input+0x123
wm_intr() at netbsd:wm_intr+0x3c0
Xresume_xenev6() at netbsd:Xresume_xenev6+0x55
--- interrupt ---
Xspllower() at netbsd:Xspllower+0xe
cnwrite() at netbsd:cnwrite+0x45
spec_write() at netbsd:spec_write+0xa4
VOP_WRITE() at netbsd:VOP_WRITE+0x2d
vn_write() at netbsd:vn_write+0xce
dofilewrite() at netbsd:dofilewrite+0x7f
sys_write() at netbsd:sys_write+0x72
syscall() at netbsd:syscall+0xb4
ds          0xe02b
es          0xe02b
fs          0x3118
gs          0x203
rdi         0
rsi         0x1
rbp         0xffffa0002a403158
rbx         0xffffa0002a403168
rdx         0
rcx         0
rax         0x1
r8          0xffffa0002a403078
r9          0x1
r10         0xffffa0002a403078
r11         0xffffffff805138b0  xenconscn_putc
r12         0x104
r13         0xffffffff808276fd  copyright+0x18e9d
r14         0x6
r15         0x1
rip         0xffffffff804d64cd  breakpoint+0x5
cs          0xe030
rflags      0x246
rsp         0xffffa0002a403158
ss          0xe02b
netbsd:breakpoint+0x5:  leave