panic: vm_fault: fault on stack guard, addr: 0xfffff80118f00000
cpuid = 5
Trace beginning at frame 0xfffff801190d91b8
vm_fault() at vm_fault+0x12eb 0xffffffff8099ef9b 
vm_fault() at vm_fault+0x12eb 0xffffffff8099ef9b 
trap_pfault() at trap_pfault+0x9a 0xffffffff80bd52ca 
trap() at trap+0x17c 0xffffffff80bd5bcc 
calltrap() at calltrap+0x9 0xffffffff80b991fa 
--- trap 000000000000000c, rip = ffffffff805b27ad, rsp = fffff801190d95c0, rbp = fffff801190d9738 ---
mps_ioctl_devsw() at mps_ioctl_devsw+0x10dd 0xffffffff805b27ad 
dev_dioctl() at dev_dioctl+0x65 0xffffffff8062cdb5 
Debugger("panic")

CPU5 stopping CPUs: 0x0000001f
 stopped
Stopped at      Debugger+0x7c:  movb    $0,0xbdaf09(%rip)
db>