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Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0xffffffffcd8a01f4
fault code              = supervisor read data, page not present
instruction pointer     = 0x8:0xffffffffb01ac2ab
stack pointer           = 0x10:0xffffffffb000c960
frame pointer           = 0x10:0xffffffffb000c990
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         = 10807 (tcsh)
trap number             = 12
panic: page fault
cpuid = 0
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
panic() at panic+0x17a
trap_fatal() at trap_fatal+0x29f
trap_pfault() at trap_pfault+0x294
trap() at trap+0x32f
calltrap() at calltrap+0x8
--- trap 0xc, rip = 0xffffffffb01ac2ab, rsp = 0xffffffffb000c960, rbp = 0xffffffffb000c990 ---
playtone() at playtone+0x8b
spkrwrite() at spkrwrite+0x4de
giant_write() at giant_write+0x60
devfs_write_f() at devfs_write_f+0x75
dofilewrite() at dofilewrite+0x85
kern_writev() at kern_writev+0x4c
write() at write+0x54
syscall() at syscall+0x254
Xfast_syscall() at Xfast_syscall+0xab
--- syscall (4, FreeBSD ELF64, write), rip = 0x8009d035c, rsp = 0x7fffffffe6d8, rbp = 0xb ---
Uptime: 10h45m9s
Physical memory: 2035 MB
Dumping 344 MB: 329 313 297 281 265 249 233 217 201 185 169 153 137 121 105 89 73 57 41 25 9