Fatal trap 12: page fault while in kernel mode
cpuid = 4; lapic id = 4
fault virtual address	= 0xfffff8006419dfe0
fault code		= supervisor read data, page not present
instruction pointer	= 0x8:0xffffffff809062e7
stack pointer	        = 0x10:0xfffff801183e3408
frame pointer	        = 0x10:0xfffff801183e3528
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 889
current thread          = pri 6 
kernel: type 12 trap, code=0

CPU4 stopping CPUs: 0x0000002f
 stopped
Stopped at      ffs_balloc+0x5e7:       movl    (%rbx,%rax,4),%eax
db>