login: panic: assertion "obj != NULL" failed in vm_object_hold_shared at /usr/src/sys/vm/vm_object.c:330
cpuid = 0
Trace beginning at frame 0xfffff800ab88b338
vm_object_hold_shared() at vm_object_hold_shared+0x3f 0xffffffff809ab0cf 
vm_object_hold_shared() at vm_object_hold_shared+0x3f 0xffffffff809ab0cf 
vm_fault() at vm_fault+0x408 0xffffffff8099d7c8 
trap_pfault() at trap_pfault+0x9a 0xffffffff80bd49da 
trap() at trap+0x17c 0xffffffff80bd52dc 
calltrap() at calltrap+0x9 0xffffffff80b9890a 
--- trap 000000000000000c, rip = ffffffff80bca038, rsp = fffff800ab88b750, rbp = fffff800ab88b7b8 ---
memmove() at memmove+0x28 0xffffffff80bca038 
Debugger("panic")

CPU0 stopping CPUs: 0x00000002
 stopped
Stopped at      Debugger+0x7c:  movb    $0,0xbd77f9(%rip)
db>