5.4-dropping to debugger

[Eirik Øverby]

On Aug 31, 2005, at 8:28 PM, Kris Kennaway wrote:

> On Wed, Aug 31, 2005 at 12:51:00PM +0200, Eirik ?verby wrote:
>
>> Hi, every once in a while (about once a week lately), one of my
>> servers has been known to stop responding. Upon connecting the serial
>> console, I find myself at a debugger prompt. This is the output I've
>> gotten this time.
>>
>> I do think I have a debug kernel on that machine, what can I do to
>> get more useful information out?
>>
>
> See the chapter on kernel debugging in the developers' handbook.

Sorry, poorly phrased question. Was in a bit of a hurry.
I have a debug kernel, however I have no dump device (and cannot  
create one; I'm geom-mirroring my disks, and for some reason I'm not  
able to specify a dump device when that is the case (has been  
discussed in the past).
I've been told that a debug kernel might still help, but the  
developers handbook does not say anything about what can be done  
without a dump. I know this has been up on one of the lists (current,  
stable or amd64) I'm on, so I guess I'll go ahead searching for it.

Sorry about the noise. Was just hoping someone recognized the symptoms.

/Eirik

> Kris
>
>
>>
>> PS: I have seen various kinds of instability on most of my 5.4-
>> installations, no matter the patchlevel. This box is just one of  
>> many.
>>
>> Anyone?
>>
>> /Eirik
>>
>> db>
>> db> c
>> Fatal trap 12: page fault while in kernel mode
>> cpuid = 1; apic id = 01
>> fault virtual address   = 0x2007010
>> fault code              = supervisor write, page not present
>> instruction pointer     = 0x8:0xc0581fe8
>> stack pointer           = 0x10:0xe3384c40
>> frame pointer           = 0x10:0xe3384c70
>> code segment            = base 0x0, limit 0xfffff, type 0x1b
>>                         = DPL 0, pres 1, def32 1, gran 1
>> processor eflags        = interrupt enabled, resume, IOPL = 0
>> current process         = 29 (irq18: fxp0)
>> [thread pid 29 tid 100000 ]
>> Stopped at      fxp_add_rfabuf+0x68:    movw    %ax,0xe(%ebx)
>> db> trace
>> Tracing pid 29 tid 100000 td 0xc22a0000
>> fxp_add_rfabuf(c2404000,c2404500,2,a6c54bb2,b51487f8) at
>> fxp_add_rfabuf+0x68
>> fxp_intr_body(c2404000,c2404000,40,ffffffff,8) at fxp_intr_body+0xf1
>> fxp_intr(c2404000,0,0,0,0) at fxp_intr+0x14e
>> ithread_loop(c22f6500,e3384d38,0,0,0) at ithread_loop+0x1b8
>> fork_exit(c06a9150,c22f6500,e3384d38) at fork_exit+0x80
>> fork_trampoline() at fork_trampoline+0x8
>> --- trap 0x1, eip = 0, esp = 0xe3384d6c, ebp = 0 ---
>>
>> _______________________________________________
>> freebsd-stable at freebsd.org mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
>> To unsubscribe, send any mail to "freebsd-stable- 
>> unsubscribe at freebsd.org"
>>
>