Re: current dom0 panic on domu launch

["Christoph Egger" <Christoph_Egger%gmx.de@localhost>]

> On 2/10/2009 7:36 AM, Manuel Bouyer wrote:
> > On Thu, Oct 01, 2009 at 10:53:51AM +1000, Sarton O'Brien wrote:
> >> Hey all,
> >>
> >> Updated a few times in the last couple of days, the most recent being
> >> yesterday (Wed Sep 30 14:23:55 EST 2009).
> >>
> >> A minute or two after launching a domu this is produced:
> >>
> >> uvm_fault(0xffffffff80c2dc60, 0x0, 1) ->  e
> >> fatal page fault in supervisor mode
> >> trap type 6 code 0 rip ffffffff80564e93 cs e030 rflags 10246 cr2  0 cpl
> >> 0 rsp ff
> >> ffa00013ac3ad0
> >> panic: trap
> >> cpu0: Begin traceback...
> >> uvm_fault(0xffffffff80c2dc60, 0x0, 1) ->  e
> >> fatal page fault in supervisor mode
> >> trap type 6 code 0 rip ffffffff802183ef cs e030 rflags 10246 cr2  0 cpl
> >> 0 rsp ff
> >> ffa00013ac3690
> >> panic: trap
> >> Faulted in mid-traceback; aborting...
> >> dump to dev 18,1 not possible
> >> panic: wdc_exec_command: polled command not done
> >> Faulted in mid-traceback; aborting...
> >> dump to dev 18,1 not possible
> >> rebooting...
> >>
> >> If more info is required, it's easy to reproduce, let me know what to
> >> do.
> >
> > Try:
> > sysctl -w ddb.onpanic=1
> > start domU, wait for crash. At the db prompt, type:
> > trace
> 
> Updated a few hours ago (5.99.20), forgot to capture the uname.
> ddb.commandonenter = trace;show registers seems to be the default (I 
> remember that being instated, great idea), the output was:
> 
> # xm create spike
> Using config file "/usr/pkg/etc/xen/spike".
> sysctl_createv: sysctl_create(xvif1.0) returned 22
> xvif1.0: could not attach sysctl nodes
> xbd backend: attach device vnd0d (size 83886080) for domain 1
> xbd backend: attach device sd0a (size 1953525168) for domain 1
> Oct  5 22:11:05 gogeta xenbackendd[305]: Failed to read 
> /local/domain/0/backend/
> console/1/0/script (No such file or directory)
> Started domain spike
> # uvm_fault(0xffffffff80c2da00, 0x0, 1) -> e
> fatal page fault in supervisor mode
> trap type 6 code 0 rip ffffffff805651f3 cs e030 rflags 10246 cr2  0 cpl 
> 0 rsp ff
> ffa00013ac3ad0
> kernel: page fault trap, code=0
> Stopped in pid 0.43 (system) at netbsd:sdioctl+0x506:   movl   
> 0(%rcx),%r8d

rcx is 0, so this is a NULL-pointer dereference.

What is the output of

   gdb netbsd.gdb
   (gdb) list *(0xffffffff805651f3)

?

You find netbsd.gdb in the same directory where you got
your self-compiled netbsd dom0 kernel from.

Christoph