Re: HEADSUP: KDB framework

On Sunday 11 July 2004 07:18, Marcel Moolenaar wrote:
> Gang,
>
> A new debugging framework has been committed. Besides adding support
> for kernel threads to both DDB and remote GDB and other nice features,
> there are some kernel configuration changes one needs to be aware of:
>

Following this commit my computer panics right after going to multiuser 
with the following:

Mounting root from ufs:/dev/ad0s1a
Pre-seeding PRNG:

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x0
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc04ccc89
stack pointer           = 0x10:0xcc417b9c
frame pointer           = 0x10:0xcc417bc8
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processors eflags       = interrupt enabled, resume, IOPL = 0
current process         = 70 (sysctl)
trap number             = 12
panic: page fault
cpuid = 0;

syncing disks, buffers remaining... 188 188 0 188 188 188 188 188 0 188 
188 0 188 188 188 0 188 0 188 188 0 188 0 188 0 188 188 0 188 0
giving up on 163 buffers
Uptime: 16s


burton# addr2line -e /usr/obj/usr/src/sys/burton/kernel.debug 0xc04ccc89
/usr/src/sys/kern/subr_kdb.c:107

I think it was becase I replaced "options DDB" with "options KDB" instead 
of adding "options KDB".  This results in no debuggers being registered 
(and thus the null pointer)?  Perhaps some checks should be added to make 
sure there really are any debuggers available before using them?

-- 
Morten Rodal

"A supercomputer is a device for turning compute-bound
 problems into I/O bound problems." -- Ken Batcher (Goodyear Aerospace)