ugen0.2: <vendor 0x0525> at usbus0
usb_probe_and_attach: iclass=2/2/255 iindex=0/0
urndis0: <vendor 0x0525 product 0xa4a2, class 2/0, rev 2.00/0.00, addr 2> on usbus0
ue0: <USB Ethernet> on urndis0
ue0: MAC address: 02:00:de:ad:be:ef
usb_probe_and_attach: iclass=2/2/255 iindex=0/0
usb_probe_and_attach: iclass=10/0/0 iindex=1/1
usb_probe_and_attach: end of interfaces at 2
urndis0: detached
usb_destroy_dev_sync: Destroying device at ugen0.2
usb_destroy_dev_sync: Destroying device at ugen0.2
usb_destroy_dev_sync: Destroying device at ugen0.2
usb_probe_and_attach: iclass=9/0/0 iindex=0/0
usb_probe_and_attach: end of interfaces at 1
ugen0.2: <vendor 0x0525> at usbus0
usb_probe_and_attach: iclass=2/2/255 iindex=0/0
usb_probe_and_attach: iclass=10/0/0 iindex=1/1
usb_probe_and_attach: end of interfaces at 2
usb_probe_and_attach: iclass=2/2/255 iindex=0/0
Fatal trap 12: page fault while in kernel mode
Stopped at      lockmgr_exclusive+0x5d: orl     (%r14),%esi
db> trace
lockmgr_exclusive() at lockmgr_exclusive+0x5d 0xffffffff80647d9d
uether_ifdetach() at uether_ifdetach+0x2f 0xffffffff82620b6f
device_doattach() at device_doattach+0x3af 0xffffffff8068dddf
usb_probe_and_attach() at usb_probe_and_attach+0x1ea 0xffffffff80a472ba
uhub_explore() at uhub_explore+0x344 0xffffffff80a4f8d4
db> bt
db> call dumpsys
db>