Fatal user address access from kernel mode from mount_hammer2 at ffffffff809831de


Fatal trap 12: page fault while in kernel mode
cpuid = 3; lapic id = 3
fault virtual address	= 0x170
fault code		= supervisor read data, page not present
instruction pointer	= 0x8:0xffffffff809831de
stack pointer	        = 0x10:0xfffff80119052a58
frame pointer	        = 0x10:0xfffff80119052ae8
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 0, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 1046
current thread          = pri 6 
kernel: type 12 trap, code=0

CPU3 stopping CPUs: 0x00000037
 stopped
Stopped at      hammer2_freemap_adjust+0xce:    movl    0x170(%rax),%r9d
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