I managed to panic my 8.0-CURRENT i386 box (kernel built from csup as
At the time I had just issued a "reboot" when the panic occurred.
Here is the kgdb output, and after that the backtrace, finally
followed by the dmesg.
I haven't been able to reproduce it, unfortunately.
root@dev:/usr/obj/usr/src/sys/DEV# kgdb kernel.debug /var/crash/vmcore.0
[GDB will not be able to debug user-mode threads:
/usr/lib/libthread_db.so: Undefined symbol "ps_pglobal_lookup"]
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This GDB was configured as "i386-marcel-freebsd".
Reading symbols from /boot/kernel/coretemp.ko...Reading symbols from
Loaded symbols for /boot/kernel/coretemp.ko
Unread portion of the kernel message buffer:
<118>Apr 2 03:03:14 dev syslogd: exiting on signal 15
Waiting (max 60 seconds) for system process `vnlru' to stop...done
iStyinncgi n(gm adxi s6k0s ,s evcnoonddess) rfeomra isnyisntge.m.
.p2r ocess `syncer' to stop...2 0 1 1 0 0 done
Waiting (max 60 seconds) for system process `bufdaemon' to stop...done
All buffers synced.
lock order reversal:
1st 0xc4f1f29c vfslock (vfslock) @ /usr/src/sys/kern/vfs_mount.c:1250
2nd 0xc4f38ce4 syncer (syncer) @ /usr/src/sys/kern/vfs_subr.c:2144
KDB: stack backtrace:
witness_checkorder(c4f38ce4,9,c07d76ef,860,0,...) at witness_checkorder+0x6de
_lockmgr_args(c4f38ce4,20002,c4f38d14,0,ffffffff,...) at ...