Re: Kernel panic in 6.0 revisited

On Tue, 2004-09-07 at 14:42, John Baldwin wrote:
> On Saturday 04 September 2004 12:57 am, Joe Marcus Clarke wrote:
> > A few days ago, I reported a kernel panic in HEAD while building
> > packages on my tinderbox machine.  I was unable to get a core dump fro
> > that crash, and after switching from ULE to 4BSD, I had thought it had
> > gone away.
> >
> > Well, today, the machine panicked twice.  It was the same panic both
> > times, and the same panic I got a few days ago.  This time, however, I
> > was able to get a core dump.  Here is the panic message:
> >
> > Fatal trap 12: page fault while in kernel mode
> > cpuid = 0; apic id = 00
> > fault virtual address   = 0x1c
> > fault code              = supervisor write, page not present
> > instruction pointer     = 0x8:0xc0533d07
> > stack pointer           = 0x10:0xf5f30a4c
> > frame pointer           = 0x10:0xf5f30a58
> > 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         = 27441 (cpp0)
> > Stopped at  vfs_vmio_release+0x1b: lock cmpxchgl %ecx,0x1c(%edx)
> >
> > And here is the output of "l *vfs_vmio_release+0x1b":
> >
> > 0xc0533d07 is in vfs_vmio_release (atomic.h:154).
> > 149     static __inline int
> > 150     atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
> > 151     {
> > 152             int res = exp;
> > 153
> > 154             __asm __volatile (
> > 155             "       " __XSTRING(MPLOCKED) " "
> > 156             "       cmpxchgl %1,%2 ;        "
> > 157             "       setz    %%al ;          "
> > 158             "       movzbl  %%al,%0 ;       "
> >
> > Kernel config is at http://www.marcuscom.com/downloads/FUGU.kernel and
> > the dmesg output is at http://www.marcuscom.com/downloads/FUGU.dmesg
> >
> > Let me know if you need anything else.  Thanks.
> 
> How about 'l *0xc0533d00' to try and figure out which function is calling 
> that.  Also, do you have INVARIANTS turned on?

Sorry, I needed the system back up, so I rebuilt without the multi-CPU
options (SMP and apic) since this is really a single-CPU machine.  Thus
far, it has not crashed, and it has done _many_ package builds.  If it
crashes again, I'll be sure to get the additional info.  No, I did not
have INVARIANTS or WITNESS enabled in the kernel.  I still do not.


Joe
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