uvm_fault(0xfffffd806ade95d0, 0x0, 0, 1) -> e fatal page fault in supervisor mode trap type 6 code 0 rip ffffffff81a26328 cs 8 rflags 10207 cr2 0 cpl 0 rsp ffff8000353f0ef0 gsbase 0xffff8000299ddff0 kgsbase 0x0 panic: trap type 6, code=0, pc=ffffffff81a26328 Starting stack trace... panic(ffffffff833d64f7) at panic+0x1d0 sys/kern/subr_prf.c:229 kerntrap(ffff8000353f0e40) at kerntrap+0x30b alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dt_ioctl_record_stop(ffff800001474000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:593 dtclose(11e5f,81,2000,ffff80003bff9778) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(11e5f,81,2000,ffff80003bff9778) at dtclose+0x109 sys/dev/dt/dt_dev.c:239 spec_close(ffff8000353f0ff0) at spec_close+0x466 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd805c526000,81,fffffd80097fd618,ffff80003bff9778) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806d977158,ffff80003bff9778) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806d977158,ffff80003bff9778) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806d977158,ffff80003bff9778) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806d977158,ffff80003bff9778) at closef+0x192 sys/kern/kern_descrip.c:1264 finishdup(ffff80003bff9778,fffffd806d977798,6,3,ffff8000353f1250,2) at finishdup+0x478 sys/kern/kern_descrip.c:688 syscall(ffff8000353f1300) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff8000353f1300) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x16e108480a0, count: 244 End of stack trace. WARNING: SPL NOT LOWERED ON SYSCALL 11 -1 EXIT 0 4 Stopped at savectx+0xae: movl $0,%gs:0x688 TID PID UID PRFLAGS PFLAGS CPU COMMAND 49302 57910 0 0x2000 0x4080000 0 syz-executor *218364 66921 0 0x2 0 1 syz-executor savectx() at savectx+0xae end of kernel end trace frame: 0x6fed9dec7ac0, 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}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic *cpu1: uvm_fault(0xfffffd806ade95d0, 0x0, 0, 1) -> e ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x6fed9dec7ac0, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff80002a3123b0 rbx 0 rdx 0 rcx 0xffff80003bff82b8 rax 0x33 r8 0xffff80002a3122e0 r9 0xffff80002a311fa8 r10 0x263f5d7e0cec4aa8 r11 0x52fcac202509b27 r12 0 r13 0 r14 0xffff80003bff82b8 r15 0 rip 0xffffffff8196c3ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff80002a312330 ss 0x10 savectx+0xae: movl $0,%gs:0x688 ddb{1}> show proc PROC (syz-executor) tid=218364 pid=66921 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=0xffff80003bff94e0,0xffff80003bff5508 process=0xffff80003bfed360 user=0xffff80002a30d000, vmspace=0xfffffd806ade9200 estcpu=36, cpticks=55, pctcpu=0.11, user=1, sys=52, intr=1 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 26268 123521 23516 0 2 0 syz-executor 26268 111090 23516 0 2 0x4000000 syz-executor 42454 97115 66921 0 2 0 syz-executor 42454 441226 66921 0 2 0x4000000 syz-executor 42454 71701 66921 0 3 0x4000000 sbar syz-executor 42454 175035 66921 0 3 0x4000080 fsleep syz-executor 88457 391389 18859 0 2 0xc80 syz-executor 88457 61492 18859 0 3 0x4000080 fsleep syz-executor 88457 152772 18859 0 3 0x4000080 ttyopn syz-executor 88457 247747 18859 0 3 0x4000080 ttyopn syz-executor 18859 37260 98906 0 2 0xc82 syz-executor 57910 182269 46357 0 4 0x82000 syz-executor 57910 314013 46357 0 2 0x4082000 syz-executor 57910 400022 46357 0 3 0x4082000 inode syz-executor 57910 179565 46357 0 3 0x4082000 inode syz-executor 57910 49302 46357 0 7 0x4082000 syz-executor 57910 391450 46357 0 4 0x4082000 syz-executor 57910 470341 46357 0 3 0x4002000 suspend syz-executor 63818 278018 302 0 3 0x3000 suspend syz-executor 63818 294026 302 0 2 0x4081000 syz-executor 27077 415641 0 0 3 0x14200 acct acct 34830 105710 98906 0 2 0x2 syz-executor 23516 243479 98906 0 2 0xc82 syz-executor 75102 504357 1 0 3 0x100083 ttyopn getty 46357 186732 98906 0 2 0xc82 syz-executor *66921 218364 98906 0 7 0x2 syz-executor 79812 398217 98906 0 3 0x82 wait syz-executor 302 223169 98906 0 2 0xc82 syz-executor 98561 283536 71481 0 3 0x100082 sbwait ndp 71481 60317 1 0 3 0x10008a sigsusp sh 88663 230440 98906 0 2 0x3 syz-executor 98906 216913 75968 0 3 0x82 kqread syz-executor 75968 337793 18479 0 3 0x10008a sigsusp ksh 18479 16058 62765 0 3 0x98 kqread sshd-session 62765 294438 49057 0 3 0x92 kqread sshd-session 49057 87355 1 0 3 0x88 kqread sshd 15564 476182 2742 74 3 0x1100092 bpf pflogd 2742 406642 1 0 3 0x80 sbwait pflogd 92590 134985 56625 73 3 0x1100090 kqread syslogd 56625 94539 1 0 3 0x100082 sbwait syslogd 27484 164195 1 0 3 0x100080 kqread resolvd 13913 122317 52165 77 3 0x100092 kqread dhcpleased 86979 24503 52165 77 3 0x100092 kqread dhcpleased 52165 342888 1 0 3 0x80 kqread dhcpleased 60479 43181 0 0 3 0x14200 bored smr 19649 492306 0 0 3 0x14200 pgzero zerothread 38659 352264 0 0 3 0x14200 aiodoned aiodoned 80663 457758 0 0 3 0x14200 syncer update 30812 91978 0 0 3 0x14200 cleaner cleaner 56355 165441 0 0 3 0x14200 reaper reaper 11 418207 0 0 3 0x14200 pgdaemon pagedaemon 89820 305569 0 0 3 0x14200 bored viomb 8577 499081 0 0 3 0x40014200 acpi0 acpi0 40077 471362 0 0 3 0x40014200 idle1 44295 221479 0 0 3 0x14200 bored softnet1 74822 75577 0 0 2 0x14200 softnet0 84418 117203 0 0 2 0x14200 systqmp 66209 440392 0 0 3 0x14200 bored systq 62941 449469 0 0 3 0x14200 netlock softclockmp 66686 152474 0 0 3 0x40014200 tmoslp softclock 65820 137452 0 0 3 0x40014200 idle0 1 398112 0 0 3 0x80082 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{1}> show all locks Process 26268 (syz-executor) thread 0xffff8000fffeed10 (111090) Process 42454 (syz-executor) thread 0xffff80003bff9778 (71701) Process 57910 (syz-executor) thread 0xffff80003bff8d18 (314013) Process 57910 (syz-executor) thread 0xffff80003bff8020 (400022) Process 63818 (syz-executor) thread 0xffff80003bff4fc8 (294026) ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10231 11075K 11454K 166960K 15409 0 pcb 17 15K 17K 166960K 812 0 rtable 181 15K 16K 166960K 1082 0 pf 39 18K 82K 166960K 438 0 ifaddr 27 5K 8K 166960K 273 0 ifgroup 59 2K 3K 166960K 506 0 sysctl 4 1K 9K 166960K 108 0 counters 72 37K 38K 166960K 712 0 ioctlops 0 0K 4K 166960K 2338 0 iov 0 0K 36K 166960K 408 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1473 93K 93K 166960K 4364 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 45 0 VM map 2 1K 1K 166960K 2 0 sem 29 136K 137K 166960K 93 0 dirhash 75 13K 14K 166960K 1167 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 20 73K 248K 166960K 3812 0 sigio 0 0K 0K 166960K 171 0 proc 76 131K 163K 166960K 1216 0 subproc 81 5K 5K 166960K 181 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 538 0 in_multi 34 2K 7K 166960K 342 0 ether_multi 1 0K 0K 166960K 23 0 mrt 1 0K 0K 166960K 28 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 115 519K 519K 166960K 115 0 exec 0 0K 1K 166960K 1403 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 4 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 286 163K 181K 166960K 36467 0 UVM aobj 14 4K 6K 166960K 17 0 pinsyscall 46 92K 106K 166960K 5257 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 321 0 NDP 15 0K 1K 166960K 208 0 temp 91 8680K 9196K 166960K 170629 0 kqueue 13 20K 32K 166960K 703 0 SYN cache 2 8K 16K 166960K 3 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 26 0 0 1 0 1 1 0 8 0 rtpcb 120 407 0 403 4 1 3 3 0 8 2 rtentry 176 317 0 267 6 2 4 6 0 8 0 unpcb 144 2634 0 2616 15 13 2 6 0 8 1 syncache 336 19 0 19 3 2 1 1 0 8 1 tcpqe 32 5 0 5 2 1 1 1 0 8 1 tcpcb 736 1270 0 1259 29 22 7 7 0 8 6 arp 136 47 0 39 1 0 1 1 0 8 0 inpcb 328 4239 0 4225 33 23 10 12 0 8 8 nd6 152 74 0 66 2 1 1 2 0 8 0 pkpcb 40 14 0 13 5 4 1 1 0 8 0 kcovpl 48 20 0 11 1 0 1 1 0 8 0 mppekey 1024 4 0 4 3 2 1 1 0 8 1 ppxss 1192 269 0 269 5 4 1 1 0 8 1 pppxif 1504 56 0 56 7 6 1 1 0 8 1 pffrag 232 25 0 14 1 0 1 1 0 482 0 pffrnode 88 23 0 12 1 0 1 1 0 8 0 pffrent 40 103 0 92 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 9 0 8 2 1 1 1 0 8 0 pfanchor 1288 1 0 0 1 0 1 1 0 8 0 pftag 88 1 0 0 1 0 1 1 0 8 0 pfstitem 24 142 0 109 1 0 1 1 0 8 0 pfstkey 128 142 0 109 3 0 3 3 0 8 0 pfstate 448 142 0 109 10 1 9 10 0 8 0 pfrule 1344 29 0 22 2 1 1 2 0 8 0 rttmr 136 3 0 3 3 2 1 1 0 8 1 art_heap8 4096 7 0 0 7 0 7 7 0 8 0 art_heap4 256 1323 0 1112 33 17 16 31 0 8 0 art_table 40 1330 0 1112 5 0 5 5 0 8 0 art_node 32 314 0 270 1 0 1 1 0 8 0 sysvmsgpl 40 8 0 3 2 1 1 1 0 8 0 semupl 112 3 0 3 2 2 0 1 0 8 0 semapl 112 80 0 53 1 0 1 1 0 8 0 shmpl 112 12 0 2 1 0 1 1 0 8 0 dirhash 1024 411 0 373 5 0 5 5 0 8 0 dino2pl 256 8389 0 6852 97 0 97 97 0 8 0 ffsino 296 8389 0 6852 119 0 119 119 0 8 0 nchpl 144 13590 0 11853 65 0 65 65 0 8 0 rtmask 32 50 0 50 6 5 1 1 0 8 1 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 49660 0 49657 4 3 1 1 0 8 0 percpumem 16 371 0 320 1 0 1 1 0 8 0 vcpupl 3968 1 0 0 1 0 1 1 0 8 0 vmpool 840 2 0 1 1 0 1 1 0 8 0 kstatmem 264 346 0 314 6 3 3 3 0 8 0 acpiwqpl 32 2 0 2 1 0 1 1 1 8 1 scsiplug 72 13 0 13 4 3 1 1 0 8 1 scxspl 216 70861 0 70861 14 13 1 8 1 8 1 plimitpl 152 999 0 978 2 0 2 2 0 8 1 sigapl 424 4107 0 4056 9 2 7 9 0 8 0 knotepl 120 654 0 0 19 0 19 19 0 8 0 kqueuepl 224 1757 0 1748 17 16 1 7 0 8 0 pipepl 344 661 0 629 23 14 9 9 0 8 5 fdescpl 528 4060 0 4026 3 0 3 3 0 8 0 filepl 160 27734 0 27487 37 21 16 19 0 8 3 lockfpl 104 1232 0 1230 1 0 1 1 0 8 0 lockfspl 48 482 0 480 1 0 1 1 0 8 0 sessionpl 144 47 0 38 1 0 1 1 0 8 0 pgrppl 48 178 0 160 1 0 1 1 0 8 0 ucredpl 104 4349 0 4335 1 0 1 1 0 8 0 zombiepl 144 5149 0 5145 2 1 1 1 0 8 0 processpl 1232 4107 0 4056 6 1 5 6 0 8 0 procpl 664 10195 0 10130 8 2 6 8 0 8 0 sosppl 176 18 0 18 3 3 0 1 0 8 0 sockpl 752 7405 0 7368 67 55 12 18 0 8 7 mcl64k 65536 27 0 0 4 0 4 4 0 8 0 mcl16k 16384 9 0 0 2 0 2 2 0 8 0 mcl12k 12288 3 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 115 0 0 15 0 15 15 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 75 0 0 8 0 8 8 0 8 0 mtagpl 96 61 0 0 2 0 2 2 0 8 0 mbufpl 256 1218 0 0 71 0 71 71 0 8 0 bufpl 280 26100 0 19964 439 0 439 439 0 8 0 anonpl 32 13337 0 0 108 0 108 108 0 246 0 amapchunkpl 152 134956 0 134349 74 45 29 39 0 158 3 amappl16 200 12287 0 11924 106 86 20 33 0 8 0 amappl15 192 8 0 8 1 1 0 1 0 8 0 amappl14 184 12 0 12 3 3 0 1 0 8 0 amappl13 176 562 0 560 1 0 1 1 0 8 0 amappl12 168 4529 0 4483 3 0 3 3 0 8 0 amappl11 160 7 0 7 2 2 0 1 0 8 0 amappl10 152 69 0 55 1 0 1 1 0 8 0 amappl9 144 251 0 250 1 0 1 1 0 8 0 amappl8 136 29 0 26 1 0 1 1 0 8 0 amappl7 128 126 0 123 1 0 1 1 0 8 0 amappl6 120 428 0 412 1 0 1 1 0 8 0 amappl5 112 90 0 79 1 0 1 1 0 8 0 amappl4 104 536 0 502 1 0 1 1 0 8 0 amappl3 96 22408 0 22292 4 1 3 3 0 8 0 amappl2 88 4255 0 4172 3 0 3 3 0 8 0 amappl1 80 28723 0 28102 16 1 15 15 0 8 0 amappl 88 34887 0 34686 5 0 5 5 0 92 0 uvmvnodes 80 201 0 0 5 0 5 5 0 8 0 dma65536 65536 2 0 2 2 2 0 1 0 8 0 dma8192 8192 1 0 1 1 1 0 1 0 8 0 dma4096 4096 2 0 2 2 2 0 1 0 8 0 dma1024 1024 2 0 1 1 0 1 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 255 0 255 3 3 0 1 0 8 0 dma64 64 7 0 7 2 2 0 1 0 8 0 dma32 32 8 0 8 2 2 0 1 0 8 0 dma16 16 19 0 18 1 0 1 1 0 8 0 aobjpl 72 16 0 3 1 0 1 1 0 8 0 uaddrrnd 24 4060 0 4026 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4060 0 4026 1 0 1 1 0 8 0 vmmpekpl 168 31760 0 31693 4 0 4 4 0 8 0 vmmpepl 168 259913 0 257471 154 45 109 114 0 357 2 vmsppl 488 4059 0 4026 5 0 5 5 0 8 0 rwobjpl 80 66780 0 65208 45 12 33 36 0 8 0 pdppl 4096 8132 0 8055 129 50 79 88 0 8 2 pvpl 32 21168 0 0 171 0 171 171 0 265 0 pmappl 256 4061 0 4027 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 431 0 103 10 0 10 10 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff83806ff0) 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(ffffffff839a9320) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff839a9320) at __mp_lock+0x192 sys/kern/kern_lock.c:165 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 __mp_lock(ffffffff839a9320) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff839a9320) at __mp_lock+0x192 sys/kern/kern_lock.c:165 uvn_io(fffffd8073d9ba20,ffff80002a2a03e8,1,202,0) at uvn_io+0x3d4 sys/uvm/uvm_vnode.c:1239 uvn_get(fffffd8073d9ba20,0,ffff80002a2a04b8,ffff80002a2a049c,0,1,6d1df54a7a98c13e,1) at uvn_get+0x31d sys/uvm/uvm_vnode.c:1089 uvm_fault_lower_io(ffff80002a2a06d0,ffff80002a2a0708,ffff80002a2a0550,ffff80002a2a0538) at uvm_fault_lower_io+0x2cd sys/uvm/uvm_fault.c:1630 uvm_fault_lower(ffff80002a2a06d0,ffff80002a2a0708,ffff80002a2a0650) at uvm_fault_lower+0x2bb sys/uvm/uvm_fault.c:1397 uvm_fault(fffffd806ade97b8,200000001000,0,1) at uvm_fault+0x274 sys/uvm/uvm_fault.c:-1 kpageflttrap(ffff80002a2a0880,200000001040) at kpageflttrap+0x2f4 sys/arch/amd64/amd64/trap.c:283 end trace frame: 0xffff80002a2a0870, count: 0 ddb{0}> trace x86_ipi_db(ffffffff83806ff0) 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(ffffffff839a9320) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff839a9320) at __mp_lock+0x192 sys/kern/kern_lock.c:165 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 __mp_lock(ffffffff839a9320) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff839a9320) at __mp_lock+0x192 sys/kern/kern_lock.c:165 uvn_io(fffffd8073d9ba20,ffff80002a2a03e8,1,202,0) at uvn_io+0x3d4 sys/uvm/uvm_vnode.c:1239 uvn_get(fffffd8073d9ba20,0,ffff80002a2a04b8,ffff80002a2a049c,0,1,6d1df54a7a98c13e,1) at uvn_get+0x31d sys/uvm/uvm_vnode.c:1089 uvm_fault_lower_io(ffff80002a2a06d0,ffff80002a2a0708,ffff80002a2a0550,ffff80002a2a0538) at uvm_fault_lower_io+0x2cd sys/uvm/uvm_fault.c:1630 uvm_fault_lower(ffff80002a2a06d0,ffff80002a2a0708,ffff80002a2a0650) at uvm_fault_lower+0x2bb sys/uvm/uvm_fault.c:1397 uvm_fault(fffffd806ade97b8,200000001000,0,1) at uvm_fault+0x274 sys/uvm/uvm_fault.c:-1 kpageflttrap(ffff80002a2a0880,200000001040) at kpageflttrap+0x2f4 sys/arch/amd64/amd64/trap.c:283 kerntrap(ffff80002a2a0880) at kerntrap+0x19c sys/arch/amd64/amd64/trap.c:520 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b _copyin() at _copyin+0x6d pipe_write(fffffd805db2c6b8,ffff80002a2a0bd0,0) at pipe_write+0x493 sys/kern/sys_pipe.c:560 dofilewritev(ffff8000fffee548,7,ffff80002a2a0bd0,0,ffff80002a2a0c90) at dofilewritev+0x242 sys/kern/sys_generic.c:380 sys_writev(ffff8000fffee548,ffff80002a2a0d40,ffff80002a2a0c90) at sys_writev+0xd8 sys/kern/sys_generic.c:327 syscall(ffff80002a2a0d40) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2a0d40) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x599c5c20880, count: -22 ddb{0}> machine ddbcpu 1 Stopped at savectx+0xae: movl $0,%gs:0x688 savectx() at savectx+0xae end of kernel end trace frame: 0x6fed9dec7ac0, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x6fed9dec7ac0, count: -1