db> bt
Tracing pid 1 tid 100002 td 0xc008000006436100
0xc008000001338ad0: at vpanic+0x208
0xc008000001338b80: at panic+0x40
0xc008000001338bb0: at trap+0x474
0xc008000001338cf0: at powerpc_interrupt+0x1cc
0xc008000001338d80: kernel ISI trap by 0x100: srr1=0x9000000040001033
            r1=0xc008000001339030 cr=0x24800c80 xer=0x20040000 ctr=0x1 r2=0xc0000000034a7000 frame=0xc008000001338db0
0xc008000001339030: at 0xfffffc0001ffc
0xc0080000013390c0: at __mtx_unlock_flags+0x70
0xc008000001339150: at moea64_is_prefaultable+0xa0
0xc0080000013391f0: at vm_fault+0x289c
0xc0080000013392d0: at vm_fault+0x1660
0xc0080000013394c0: at vm_fault_trap+0xa0
0xc008000001339560: at trap+0x13c0
0xc008000001339610: at trap+0x4a0
0xc008000001339750: at powerpc_interrupt+0x1cc
0xc0080000013397e0: user DSI write trap @ 0xfffffbfffe4f0 by 0x100752ec: srr1=0x900000000280f933
            r1=0xfffffbfffe4e0 cr=0x42000b82 xer=0x20040000 ctr=0x100a71c0 r2=0x101b2900 sr=0xa000000 frame=0xc008000001339810