Re: kernel panic during reboot

On Sun, Jun 24, 2007 at 11:40:19AM +0200, Pascal Hofstee wrote:
> Hi,
> 
> After updating CURRENT yesterday (Sat June 23rd) i am now seeing a
> kernel panic during reboot ... i have a crashdump and can provide the
> following backtrace ... if additional information is needed i can
> probably provide it .. just tell me how to obtain it (not too familiar
> with kgdb myself):
> 
> Waiting (max 60 seconds) for system process `bufdaemon' to stop...done
> Waiting (max 60 seconds) for system process `syncer' to stop...
> Syncing disks, vnodes remaining...7 5 3 2 1 0 1 0 0 0 done
> All buffers synced.
> panic: vput: negative ref cnt
> cpuid = 0
> KDB: enter: panic
> panic: from debugger
> cpuid = 0
> Uptime: 23m42s
> Physical memory: 2027 MB
> Dumping 128 MB: 113 97 81 65 49 33 17 1
> 
> #0  doadump () at pcpu.h:195
> 195             __asm __volatile("movl %%fs:0,%0" : "=r" (td));
> (kgdb) backtrace
> #0  doadump () at pcpu.h:195
> #1  0xc075b197 in boot (howto=260)
> at /usr/src/sys/kern/kern_shutdown.c:409
> #2  0xc075b48e in panic (fmt=Variable "fmt" is not available.
> ) at /usr/src/sys/kern/kern_shutdown.c:563
> #3  0xc0495617 in db_panic (addr=Could not find the frame base for
> "db_panic".
> ) at /usr/src/sys/ddb/db_command.c:433
> #4  0xc0495d75 in db_command_loop ()
> at /usr/src/sys/ddb/db_command.c:401
> #5  0xc04977b5 in db_trap (type=3, code=0)
> at /usr/src/sys/ddb/db_main.c:222
> #6  0xc0782ac5 in kdb_trap (type=3, code=0, tf=0xe45cfafc)
> at /usr/src/sys/kern/subr_kdb.c:502
> #7  0xc0a1a4bb in trap (frame=0xe45cfafc)
> at /usr/src/sys/i386/i386/trap.c:620
> #8  0xc09ffc2b in calltrap () at /usr/src/sys/i386/i386/exception.s:139
> #9  0xc0782c42 in kdb_enter (msg=0xc0aa8388 "panic") at cpufunc.h:60
> #10 0xc075b474 in panic (fmt=0xc0aae946 "vput: negative ref cnt")
> at /usr/src/sys/kern/kern_shutdown.c:547
> #11 0xc07d7783 in vput (vp=0xc5b3e990)
> at /usr/src/sys/kern/vfs_subr.c:2176
For start, show the output of "p/x *vp"  at this frame.