uvm_fault(fffffd80089ae450,8bda464f000,0,4) at uvm_fault+0x238
upageflttrap(ffff80002ba0fdd0,8bda464fd4f) at upageflttrap+0x85 sys/arch/amd64/amd64/trap.c:186
usertrap(ffff80002ba0fdd0) at usertrap+0x204 sys/arch/amd64/amd64/trap.c:438
recall_trap() at recall_trap+0x8
end of kernel
end trace frame: 0x7f7ffffdbcd0, count: -16
ddb{0}> machine ddbcpu 1
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
ddb{1}> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437
witness_checkorder(fffffd806d486a38,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2502 [inline]
witness_checkorder(fffffd806d486a38,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1105
rw_enter(fffffd806d486a28,1) at rw_enter+0xd1 sys/kern/kern_rwlock.c:250
rrw_enter(fffffd806d486a28,1) at rrw_enter+0x8b sys/kern/kern_rwlock.c:465
VOP_LOCK(fffffd807dcbd6f8,2001) at VOP_LOCK+0x87 sys/kern/vfs_vops.c:518
vn_lock(fffffd807dcbd6f8,2001) at vn_lock+0x84 sys/kern/vfs_vnops.c:564
vn_rdwr(1,fffffd807dcbd6f8,ffff800008a43180,1,0,1,2bc5f0286a1df158,ffff8000006b6000,fffffd80678965b0,0) at vn_rdwr+0xb1 sys/kern/vfs_vnops.c:320
vndstrategy(fffffd80678965b0) at vndstrategy+0x3c4 sys/dev/vnd.c:341
physio(ffffffff8249c100,2902,0,ffffffff810575b0,ffff80002ba03b30) at physio+0x289 sys/kern/kern_physio.c:163
spec_write(ffff80002ba03910) at spec_write+0xd8 sys/kern/spec_vnops.c:302
VOP_WRITE(fffffd806edb0648,ffff80002ba03b30,1,fffffd807f7d75b0) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245
vn_write(fffffd806efb5398,ffff80002ba03b30,0) at vn_write+0x157 sys/kern/vfs_vnops.c:408
dofilewritev(ffff800021297340,3,ffff80002ba03b30,0,ffff80002ba03c20) at dofilewritev+0x19c sys/kern/sys_generic.c:375
sys_writev(ffff800021297340,ffff80002ba03bd8,ffff80002ba03c20) at sys_writev+0xa7 sys/kern/sys_generic.c:322
syscall(ffff80002ba03ca0) at syscall+0x57c mi_syscall sys/sys/syscall_mi.h:113 [inline]
syscall(ffff80002ba03ca0) at syscall+0x57c sys/arch/amd64/amd64/trap.c:626
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x31859285480, count: -16