uvm_fault(0xfffffd806bcc5ad0, 0x0, 0, 1) -> e fatal page fault in supervisor mode trap type 6 code 0 rip ffffffff8135d780 cs 8 rflags 10207 cr2 0 cpl 0 rsp ffff80002ec9e810 gsbase 0xffff800029a9bff0 kgsbase 0x0 panic: trap type 6, code=0, pc=ffffffff8135d780 Starting stack trace... panic(ffffffff8332133d) at panic+0x1d0 sys/kern/subr_prf.c:229 kerntrap(ffff80002ec9e760) at kerntrap+0x29b sys/arch/amd64/amd64/trap.c:327 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dt_ioctl_record_stop(ffff800001487000) at dt_ioctl_record_stop+0xf0 sys/dev/dt/dt_dev.c:579 dtclose(11e5f,81,2000,ffff80002a48ca78) at dtclose+0x105 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(11e5f,81,2000,ffff80002a48ca78) at dtclose+0x105 sys/dev/dt/dt_dev.c:232 spec_close(ffff80002ec9e910) at spec_close+0x45f sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8078bd91b0,81,fffffd807f7d3000,ffff80002a48ca78) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806be921c8,ffff80002a48ca78) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806be921c8,ffff80002a48ca78) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806be921c8,ffff80002a48ca78) at fdrop+0x126 sys/kern/kern_descrip.c:1265 closef(fffffd806be921c8,ffff80002a48ca78) at closef+0x192 sys/kern/kern_descrip.c:1249 fdfree(ffff80002a48ca78) at fdfree+0x116 sys/kern/kern_descrip.c:1181 exit1(ffff80002a48ca78,0,0,1) at exit1+0x58f sys/kern/kern_exit.c:214 sys_exit(ffff80002a48ca78,ffff80002ec9ec80,ffff80002ec9ebd0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80002ec9ec80) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002ec9ec80) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x71c6b1fd6330, count: 242 End of stack trace. WARNING: SPL NOT LOWERED ON SYSCALL 11 -1 EXIT 0 4 Stopped at savectx+0xae: movl $0,%gs:0x680 TID PID UID PRFLAGS PFLAGS CPU COMMAND 232879 87378 0 0 0x1 0 syz-executor *190465 96161 0 0x2 0 1 syz-executor savectx() at savectx+0xae end of kernel end trace frame: 0x71c6b1fd6330, count: 14 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic *cpu1: uvm_fault(0xfffffd806bcc5ad0, 0x0, 0, 1) -> e ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x71c6b1fd6330, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff80002a43a3e0 rbx 0 rdx 0 rcx 0xffff80002a3919b8 rax 0x33 r8 0xffff80002a43a310 r9 0x1 r10 0x53ed34b8230af68c r11 0xf6622b4f666fc50f r12 0 r13 0 r14 0xffff80002a3919b8 r15 0 rip 0xffffffff8114e3ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff80002a43a360 ss 0 savectx+0xae: movl $0,%gs:0x680 ddb{1}> show proc PROC (syz-executor) tid=190465 pid=96161 tcnt=1 stat=onproc flags process=2 proc=0 runpri=50, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a391498,0xffff80002a2f8a58 process=0xffff80002a301700 user=0xffff80002a435000, vmspace=0xfffffd8009b2a390 estcpu=36, cpticks=2, pctcpu=0.95, user=0, sys=153, intr=2 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 85336 428332 46802 0 2 0 syz-executor 23827 359729 5200 0 3 0x80 nanoslp syz-executor 23827 30969 5200 0 3 0x4000080 kqread syz-executor 23827 168384 5200 0 3 0x4000080 fsleep syz-executor 56549 76553 3544 0 3 0x80 nanoslp syz-executor 56549 197616 3544 0 3 0x4000080 kqsel syz-executor 56549 286623 3544 0 3 0x4000080 fsleep syz-executor 69003 29050 99101 0 3 0x80 nanoslp syz-executor 69003 387674 99101 0 3 0x4000080 ttyout syz-executor 69003 168727 99101 0 3 0x4000080 ttyout syz-executor 69003 219355 99101 0 3 0x4000080 fsleep syz-executor 2591 211705 43437 0 3 0x80 nanoslp syz-executor 2591 268661 43437 0 3 0x4000080 kqpoll syz-executor 2591 166746 43437 0 3 0x4000080 fsleep syz-executor 87378 232879 59297 0 7 0x1 syz-executor 87378 24320 59297 0 3 0x4000080 kqread syz-executor 87378 207564 59297 0 3 0x4000080 fsleep syz-executor 59297 297501 54115 0 3 0x82 nanoslp syz-executor 86207 253200 0 0 3 0x14280 nfsidl nfsio 49050 133957 0 0 3 0x14280 nfsidl nfsio 56681 336949 0 0 3 0x14280 nfsidl nfsio 73664 427821 0 0 3 0x14280 nfsidl nfsio 7213 72273 0 0 3 0x14280 nfsidl nfsio 63597 35133 0 0 3 0x14280 nfsidl nfsio 47813 41810 0 0 3 0x14280 nfsidl nfsio 14786 48814 0 0 3 0x14280 nfsidl nfsio 41192 197085 0 0 3 0x14280 nfsidl nfsio 40555 444020 0 0 3 0x14280 nfsidl nfsio 72634 354388 0 0 3 0x14280 nfsidl nfsio 975 289576 0 0 3 0x14280 nfsidl nfsio 6970 99813 0 0 3 0x14280 nfsidl nfsio 78641 281523 0 0 3 0x14280 nfsidl nfsio 72367 111370 0 0 3 0x14280 nfsidl nfsio 48473 369927 0 0 3 0x14280 nfsidl nfsio 65980 446806 0 0 3 0x14280 nfsidl nfsio 67575 300304 0 0 3 0x14280 nfsidl nfsio 93041 244091 0 0 3 0x14280 nfsidl nfsio 63583 271595 0 0 3 0x14280 nfsidl nfsio 99101 82914 54115 0 3 0x82 nanoslp syz-executor 46802 191781 54115 0 3 0x82 nanoslp syz-executor 73850 333608 1 0 3 0x100083 ttyin getty 26474 265343 0 0 3 0x14200 bored sosplice 76780 350575 54115 0 3 0x2 biowait syz-executor 43437 107700 54115 0 3 0x82 nanoslp syz-executor *96161 190465 54115 0 7 0x2 syz-executor 3544 313954 54115 0 3 0x82 nanoslp syz-executor 5200 271227 54115 0 3 0x82 nanoslp syz-executor 54115 60886 81657 0 3 0x82 kqread syz-executor 81657 117929 9995 0 3 0x10008a sigsusp ksh 9995 83945 41052 0 3 0x98 kqread sshd-session 41052 308240 58896 0 3 0x92 kqread sshd-session 58896 346494 1 0 3 0x88 kqread sshd 70288 74028 88767 74 3 0x1100092 bpf pflogd 88767 131966 1 0 3 0x80 sbwait pflogd 59358 389971 29242 73 3 0x1100090 kqread syslogd 29242 292867 1 0 3 0x100082 sbwait syslogd 52940 262619 1 0 3 0x100080 kqread resolvd 7372 190536 17887 77 3 0x100092 kqread dhcpleased 36893 129047 17887 77 3 0x100092 kqread dhcpleased 17887 435350 1 0 3 0x80 kqread dhcpleased 87420 261544 0 0 3 0x14200 bored smr 32884 357805 0 0 3 0x14200 pgzero zerothread 5507 179723 0 0 3 0x14200 aiodoned aiodoned 82604 236753 0 0 3 0x14200 syncer update 54667 107134 0 0 3 0x14200 cleaner cleaner 88220 170514 0 0 3 0x14200 reaper reaper 15443 285341 0 0 3 0x14200 pgdaemon pagedaemon 45283 329645 0 0 3 0x14200 bored viomb 35750 214231 0 0 3 0x40014200 acpi0 acpi0 20466 98113 0 0 3 0x40014200 idle1 70473 245916 0 0 3 0x14200 bored softnet3 77899 440913 0 0 3 0x14200 bored softnet2 84426 44712 0 0 3 0x14200 bored softnet1 15267 523488 0 0 3 0x14200 netlock softnet0 9734 118679 0 0 2 0x40014200 systqmp 21658 288326 0 0 3 0x14200 bored systq 37806 472879 0 0 3 0x14200 tmoslp softclockmp 51113 290756 0 0 3 0x40014200 tmoslp softclock 63065 3990 0 0 3 0x40014200 idle0 1 306202 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{1}> show all locks Process 76780 (syz-executor) thread 0xffff80002a2f9718 (350575) ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10222 11077K 13693K 166960K 14696 0 pcb 19 14K 16K 166960K 582 0 rtable 165 10K 11K 166960K 677 0 pf 34 17K 22K 166960K 192 0 ifaddr 33 5K 7K 166960K 122 0 ifgroup 51 2K 2K 166960K 216 0 sysctl 4 1K 1K 166960K 8 0 counters 62 36K 37K 166960K 226 0 ioctlops 0 0K 8K 166960K 1882 0 iov 0 0K 20K 166960K 186 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1585 100K 101K 166960K 3523 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 30 0 VM map 2 1K 1K 166960K 2 0 sem 23 11K 11K 166960K 69 0 dirhash 12 2K 2K 166960K 36 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 89K 166960K 2010 0 sigio 1 0K 0K 166960K 45 0 proc 73 91K 116K 166960K 832 0 subproc 72 4K 4K 166960K 99 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 1 0K 0K 166960K 327 0 in_multi 64 4K 7K 166960K 226 0 ether_multi 1 0K 0K 166960K 23 0 mrt 1 0K 0K 166960K 13 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 193 864K 864K 166960K 193 0 exec 0 0K 1K 166960K 726 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 70 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 255 161K 176K 166960K 19840 0 UVM aobj 58 5K 5K 166960K 61 0 pinsyscall 42 84K 104K 166960K 3225 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 236 0 NDP 11 0K 2K 166960K 85 0 temp 80 8692K 8766K 166960K 85460 0 kqueue 16 22K 32K 166960K 393 0 SYN cache 2 16K 16K 166960K 2 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 24 0 0 1 0 1 1 0 8 0 rtpcb 120 252 0 249 3 2 1 3 0 8 0 rtentry 168 188 0 124 5 0 5 5 0 8 0 unpcb 144 1519 0 1499 15 11 4 6 0 8 3 syncache 336 14 0 14 5 4 1 1 0 8 1 tcpqe 32 3 0 3 2 2 0 1 0 8 0 tcpcb 808 782 0 775 23 21 2 8 0 8 0 arp 120 27 0 16 1 0 1 1 0 8 0 inpcb 376 2636 0 2618 27 20 7 12 0 8 4 nd6 136 37 0 23 1 0 1 1 0 8 0 pkpcb 40 21 0 21 5 4 1 1 0 8 1 kcovpl 48 11 0 3 1 0 1 1 0 8 0 mppekey 1024 3 0 3 3 3 0 1 0 8 0 ppxss 1168 59 0 59 4 3 1 1 0 8 1 pppxif 1480 8 0 8 4 3 1 1 0 8 1 pfstscr 40 2 0 2 1 1 0 1 0 8 0 pffrag 232 27 0 20 1 0 1 1 0 482 0 pffrnode 88 23 0 17 1 0 1 1 0 8 0 pffrent 40 49 0 42 1 0 1 1 0 8 0 pfosfp 40 1428 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfrktable 1344 2 0 2 1 1 0 1 0 8 0 pfanchor 1288 1 0 0 1 0 1 1 0 8 0 pftag 88 2 0 0 1 0 1 1 0 8 0 pfstitem 24 121 0 54 1 0 1 1 0 8 0 pfstkey 128 122 0 55 3 0 3 3 0 8 0 pfstate 376 121 0 55 7 0 7 7 0 8 0 pfrule 1344 29 0 22 2 1 1 2 0 8 0 rttmr 136 1 0 1 1 1 0 1 0 8 0 art_heap8 4096 3 0 0 3 0 3 3 0 8 0 art_heap4 256 786 0 468 33 9 24 29 0 8 2 art_table 32 789 0 468 4 0 4 4 0 8 0 art_node 16 177 0 120 1 0 1 1 0 8 0 sysvmsgpl 40 14 0 12 2 1 1 1 0 8 0 semupl 112 2 0 2 2 2 0 1 0 8 0 semapl 112 62 0 41 1 0 1 1 0 8 0 shmpl 112 58 0 3 2 0 2 2 0 8 0 dirhash 1024 33 0 16 3 0 3 3 0 8 0 dino2pl 256 5243 0 3734 95 0 95 95 0 8 0 ffsino 280 5243 0 3734 109 0 109 109 0 8 0 nchpl 144 8076 0 7527 64 39 25 64 0 8 0 rtmask 32 14 0 14 5 5 0 1 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 29821 0 29821 2 1 1 2 0 8 1 percpumem 16 127 0 82 1 0 1 1 0 8 0 kstatmem 264 124 0 102 4 2 2 3 0 8 0 acpiwqpl 32 3 0 3 1 0 1 1 1 8 1 scsiplug 72 7 0 7 4 4 0 1 0 8 0 scxspl 216 23445 0 23444 13 12 1 8 1 8 0 plimitpl 152 482 0 464 1 0 1 1 0 8 0 sigapl 424 2339 0 2269 10 1 9 9 0 8 0 futexpl 64 29923 0 29918 1 0 1 1 0 8 0 knotepl 120 579 0 0 17 0 17 17 0 8 0 kqueuepl 216 982 0 968 17 16 1 7 0 8 0 pipepl 328 255 0 227 3 0 3 3 0 8 0 fdescpl 504 2296 0 2265 5 0 5 5 0 8 0 filepl 152 17510 0 17278 40 26 14 25 0 8 3 lockfpl 104 792 0 789 3 2 1 2 0 8 0 lockfspl 48 306 0 303 1 0 1 1 0 8 0 sessionpl 144 37 0 28 1 0 1 1 0 8 0 pgrppl 48 71 0 54 1 0 1 1 0 8 0 ucredpl 104 2715 0 2700 1 0 1 1 0 8 0 zombiepl 144 2270 0 2269 2 1 1 1 0 8 0 processpl 1176 2339 0 2269 6 0 6 6 0 8 0 procpl 656 5354 0 5273 8 0 8 8 0 8 0 srpgc 96 14 0 14 5 4 1 1 0 8 1 sosppl 168 11 0 11 3 2 1 1 0 8 1 sockpl 688 4460 0 4421 33 23 10 16 0 8 5 mcl64k 65536 7 0 0 1 0 1 1 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 126 0 0 16 0 16 16 0 8 0 mcl2k 2048 28 0 0 3 0 3 3 0 8 0 mtagpl 96 65 0 0 2 0 2 2 0 8 0 mbufpl 256 3455 0 0 214 0 214 214 0 8 0 bufpl 280 6885 0 731 440 0 440 440 0 8 0 anonpl 24 276713 0 267886 94 16 78 91 0 184 0 amapchunkpl 152 65930 0 65302 49 17 32 34 0 158 4 amappl16 200 4295 0 4028 32 5 27 28 0 8 0 amappl15 192 8 0 8 1 1 0 1 0 8 0 amappl14 184 152 0 140 1 0 1 1 0 8 0 amappl13 176 2 0 2 2 2 0 1 0 8 0 amappl12 168 2994 0 2963 4 2 2 3 0 8 0 amappl11 160 48 0 33 1 0 1 1 0 8 0 amappl10 152 9 0 9 1 1 0 1 0 8 0 amappl9 144 254 0 254 1 1 0 1 0 8 0 amappl8 136 27 0 24 1 0 1 1 0 8 0 amappl7 128 122 0 110 1 0 1 1 0 8 0 amappl6 120 213 0 210 1 0 1 1 0 8 0 amappl5 112 202 0 192 1 0 1 1 0 8 0 amappl4 104 374 0 351 1 0 1 1 0 8 0 amappl3 96 13822 0 13707 5 1 4 4 0 8 0 amappl2 88 769 0 706 2 0 2 2 0 8 0 amappl1 80 18607 0 18004 15 0 15 15 0 8 0 amappl 88 18625 0 18443 5 0 5 5 0 92 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 7 0 7 2 2 0 1 0 8 0 dma128 128 256 0 256 3 3 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 8 0 8 2 2 0 1 0 8 0 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 72 60 0 3 2 0 2 2 0 8 0 uaddrrnd 24 2296 0 2265 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2296 0 2265 1 0 1 1 0 8 0 vmmpekpl 168 19629 0 19573 3 0 3 3 0 8 0 vmmpepl 168 148148 0 145898 118 9 109 111 0 357 0 vmsppl 456 2295 0 2265 5 0 5 5 0 8 0 rwobjpl 64 42360 0 35186 121 3 118 120 0 8 0 pdppl 4096 4600 0 4530 132 58 74 86 0 8 4 pvpl 32 21501 0 0 174 1 173 173 0 265 0 pmappl 248 2295 0 2265 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 552 0 105 13 0 13 13 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff8385cff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394 x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __mp_lock(ffffffff838ffad8) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff838ffad8) at __mp_lock+0x192 sys/kern/kern_lock.c:144 softintr_dispatch(2) at softintr_dispatch+0x5b sys/arch/amd64/amd64/softintr.c:88 Xsofttty() at Xsofttty+0x27 __mp_lock(ffffffff838ffad8) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff838ffad8) at __mp_lock+0x192 sys/kern/kern_lock.c:144 intr_handler(ffff8000384f8470,ffff800000079f00) at intr_handler+0xe1 sys/arch/amd64/amd64/intr.c:553 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f __mp_lock(ffffffff838ffad8) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff838ffad8) at __mp_lock+0x199 sys/kern/kern_lock.c:144 ktrsysret(ffff80002a48cd08,4a,0,ffff8000384f8660) at ktrsysret+0xe1 ktrwrite2 sys/kern/kern_ktrace.c:-1 [inline] ktrsysret(ffff80002a48cd08,4a,0,ffff8000384f8660) at ktrsysret+0xe1 sys/kern/kern_ktrace.c:209 syscall(ffff8000384f8710) at syscall+0xa43 mi_syscall_return sys/sys/syscall_mi.h:204 [inline] syscall(ffff8000384f8710) at syscall+0xa43 sys/arch/amd64/amd64/trap.c:598 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7d99ccfa1bc0, count: 2 ddb{0}> trace x86_ipi_db(ffffffff8385cff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394 x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __mp_lock(ffffffff838ffad8) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff838ffad8) at __mp_lock+0x192 sys/kern/kern_lock.c:144 softintr_dispatch(2) at softintr_dispatch+0x5b sys/arch/amd64/amd64/softintr.c:88 Xsofttty() at Xsofttty+0x27 __mp_lock(ffffffff838ffad8) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff838ffad8) at __mp_lock+0x192 sys/kern/kern_lock.c:144 intr_handler(ffff8000384f8470,ffff800000079f00) at intr_handler+0xe1 sys/arch/amd64/amd64/intr.c:553 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f __mp_lock(ffffffff838ffad8) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff838ffad8) at __mp_lock+0x199 sys/kern/kern_lock.c:144 ktrsysret(ffff80002a48cd08,4a,0,ffff8000384f8660) at ktrsysret+0xe1 ktrwrite2 sys/kern/kern_ktrace.c:-1 [inline] ktrsysret(ffff80002a48cd08,4a,0,ffff8000384f8660) at ktrsysret+0xe1 sys/kern/kern_ktrace.c:209 syscall(ffff8000384f8710) at syscall+0xa43 mi_syscall_return sys/sys/syscall_mi.h:204 [inline] syscall(ffff8000384f8710) at syscall+0xa43 sys/arch/amd64/amd64/trap.c:598 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7d99ccfa1bc0, count: -13 ddb{0}> machine ddbcpu 1 Stopped at savectx+0xae: movl $0,%gs:0x680 savectx() at savectx+0xae end of kernel end trace frame: 0x71c6b1fd6330, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x71c6b1fd6330, count: -1