Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address	= 0x0
fault code		= supervisor read data, page not present
instruction pointer	= 0x20:0xffffffff8157f011
stack pointer	        = 0x28:0xfffffe0056b485c0
frame pointer	        = 0x28:0xfffffe0056b48700
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags	= resume, IOPL = 0
current process		= 12 (swi1: hpts)
rdi: 0000000000000000 rsi: 0000000000000000 rdx: 0000000000000000
rcx: fffffe0002bf1850  r8: 0000000000000000  r9: 0000000000000001
rax: fffffe0000000000 rbx: fffffe00540f0f40 rbp: fffffe0056b48700
r10: bb90e4d3e7a87777 r11: 0000000000000017 r12: 0000000000000000
r13: 00000036be13508b r14: fffffe00540f0f38 r15: 0000000000000000
trap number		= 12
panic: page fault
cpuid = 0
time = 14
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0xc6/frame 0xfffffe0056b47df0
kdb_backtrace() at kdb_backtrace+0xd0/frame 0xfffffe0056b47f50
vpanic() at vpanic+0x257/frame 0xfffffe0056b48110
panic() at panic+0xb5/frame 0xfffffe0056b481d0
trap_pfault() at trap_pfault+0xaf2/frame 0xfffffe0056b48310
trap() at trap+0x78e/frame 0xfffffe0056b484f0
calltrap() at calltrap+0x8/frame 0xfffffe0056b484f0
--- trap 0xc, rip = 0xffffffff8157f011, rsp = 0xfffffe0056b485c0, rbp = 0xfffffe0056b48700 ---
callout_process() at callout_process+0x441/frame 0xfffffe0056b48700
handleevents() at handleevents+0x3ee/frame 0xfffffe0056b48770
timercb() at timercb+0x3cb/frame 0xfffffe0056b48830
lapic_handle_timer() at lapic_handle_timer+0x17f/frame 0xfffffe0056b48870
Xtimerint() at Xtimerint+0xb1/frame 0xfffffe0056b48870
--- interrupt, rip = 0xffffffff81a1307e, rsp = 0xfffffe0056b48940, rbp = 0xfffffe0056b48c90 ---
tcp_hptsi() at tcp_hptsi+0xc7e/frame 0xfffffe0056b48c90
tcp_hpts_thread() at tcp_hpts_thread+0x303/frame 0xfffffe0056b48d90
ithread_loop() at ithread_loop+0x4ec/frame 0xfffffe0056b48ef0
fork_exit() at fork_exit+0xcc/frame 0xfffffe0056b48f30
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0056b48f30
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
KDB: enter: panic
[ thread pid 12 tid 100034 ]
Stopped at      kdb_enter+0x6e: movq    $0,0x25b6f77(%rip)
db> 
db> set $lines = 0
db> set $maxwidth = 0
db> show registers
cs                        0x20
ds                        0x3b
es                        0x3b
fs                        0x13
gs                        0x1b
ss                        0x28
rax                       0x12
rcx         0xfffffe0002bf1850
rdx                          0
rbx         0xffffffff827e1820  .str.27
rsp         0xfffffe0056b47f30
rbp         0xfffffe0056b47f50
rsi                          0
rdi         0xffffffff816260e9  printf+0x149
r8                           0
r9                  0xffffffff
r10                          0
r11                       0x17
r12         0xfffffe0007821000
r13         0xfffffffffffffffe
r14         0xffffffff827e1820  .str.27
r15                          0
rip         0xffffffff8160fc1e  kdb_enter+0x6e
rflags                    0x46
kdb_enter+0x6e: movq    $0,0x25b6f77(%rip)
db>