uvm_fault(0xfffffd806c9133f0, 0x0, 0, 1) -> e fatal page fault in supervisor mode trap type 6 code 0 rip ffffffff81e2a5f8 cs 8 rflags 10207 cr2 0 cpl 0 rsp ffff800033be3690 gsbase 0xffff8000299ddff0 kgsbase 0x0 panic: trap type 6, code=0, pc=ffffffff81e2a5f8 Starting stack trace... panic(ffffffff833e71c7) at panic+0x1d0 sys/kern/subr_prf.c:229 kerntrap(ffff800033be35e0) at kerntrap+0x30b alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dt_ioctl_record_stop(ffff800001628000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:593 dtclose(31e5f,81,2000,ffff800039ff8a80) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(31e5f,81,2000,ffff800039ff8a80) at dtclose+0x109 sys/dev/dt/dt_dev.c:239 spec_close(ffff800033be3790) at spec_close+0x466 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd805e4ef6f8,81,fffffd80097fd478,ffff800039ff8a80) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8068238330,ffff800039ff8a80) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8068238330,ffff800039ff8a80) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd8068238330,ffff800039ff8a80) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd8068238330,ffff800039ff8a80) at closef+0x192 sys/kern/kern_descrip.c:1264 syscall(ffff800033be39f0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800033be39f0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x678eddaf4b0, count: 245 End of stack trace. WARNING: SPL NOT LOWERED ON SYSCALL 83 1318540096 EXIT 0 4 Stopped at savectx+0xae: movl $0,%gs:0x688 TID PID UID PRFLAGS PFLAGS CPU COMMAND *461108 39449 0 0 0 1 syz-executor 471967 50683 0 0x2 0x1 0 syz-executor savectx() at savectx+0xae end of kernel end trace frame: 0x7a4c5506ca90, 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(0xfffffd806c9133f0, 0x0, 0, 1) -> e ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x7a4c5506ca90, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff8000367e98e0 rbx 0 rdx 0 rcx 0xffff800039ff9248 rax 0x3b r8 0xffff8000367e9810 r9 0x1 r10 0x9b9e48cf0ae88bba r11 0xf30f8c986ab7a7a0 r12 0 r13 0 r14 0xffff800039ff9248 r15 0 rip 0xffffffff832793ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff8000367e9860 ss 0x10 savectx+0xae: movl $0,%gs:0x688 ddb{1}> show proc PROC (syz-executor) tid=461108 pid=39449 tcnt=3 stat=onproc flags process=0 proc=0 runpri=50, usrpri=50, slppri=36, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff800039ff82b8,0xffff800039ff8a90 process=0xffff800039fec020 user=0xffff8000367e4000, vmspace=0xfffffd806c9133f0 estcpu=36, cpticks=2, pctcpu=0.0, user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND *39449 461108 95930 0 7 0 syz-executor 39449 512731 95930 0 3 0x4000000 sbar syz-executor 39449 450004 95930 0 3 0x4000080 fsleep syz-executor 60205 23815 53559 0 2 0 syz-executor 60205 343717 53559 0 3 0x4000080 fsleep syz-executor 60205 513568 53559 0 2 0x4000000 syz-executor 53938 441844 71719 0 2 0 syz-executor 53938 326409 71719 0 3 0x4000080 fsleep syz-executor 53938 452034 71719 0 3 0x4000080 fsleep syz-executor 53938 435700 71719 0 3 0x4000080 fsleep syz-executor 58067 439858 69191 0 3 0x80 nanoslp syz-executor 58067 192169 69191 0 3 0x4000080 netacc syz-executor 58067 515682 69191 0 3 0x4000080 fsleep syz-executor 26927 17097 0 0 3 0x14200 acct acct 69191 248242 61223 0 3 0x82 nanoslp syz-executor 83660 133474 17553 0 3 0x82 sbwait sshd-session 95930 2865 61223 0 3 0x82 nanoslp syz-executor 50683 471967 61223 0 7 0x3 syz-executor 89634 273692 60416 0 3 0x100082 sbwait arp 60416 494044 96196 0 3 0x10008a sigsusp sh 19241 44297 61223 0 3 0x82 wait syz-executor 96196 484602 61223 0 3 0x82 wait syz-executor 53559 419542 61223 0 3 0x82 nanoslp syz-executor 90816 112481 61223 0 3 0x82 nanoslp syz-executor 71719 333105 61223 0 3 0x82 nanoslp syz-executor 61223 290760 59826 0 2 0x3 syz-executor 59826 389610 725 0 3 0x10008a sigsusp ksh 725 174814 26508 0 3 0x98 kqread sshd-session 26508 267667 17553 0 3 0x92 kqread sshd-session 10457 362284 1 0 3 0x100083 ttyin getty 17553 82920 1 0 3 0x88 kqread sshd 15822 183020 140 74 3 0x1100092 bpf pflogd 140 359930 1 0 3 0x80 sbwait pflogd 66884 167806 87239 73 3 0x1100090 kqread syslogd 87239 485652 1 0 3 0x100082 sbwait syslogd 59759 388508 1 0 3 0x100080 kqread resolvd 49052 297193 17056 77 3 0x100092 kqread dhcpleased 14196 284446 17056 77 3 0x100092 kqread dhcpleased 17056 333238 1 0 3 0x80 kqread dhcpleased 24226 495494 0 0 3 0x14200 bored smr 24612 356236 0 0 2 0x14200 zerothread 64649 102098 0 0 3 0x14200 aiodoned aiodoned 29345 145439 0 0 3 0x14200 syncer update 71456 360955 0 0 3 0x14200 cleaner cleaner 24285 305680 0 0 3 0x14200 reaper reaper 92878 94535 0 0 3 0x14200 pgdaemon pagedaemon 59035 489246 0 0 3 0x14200 bored viomb 85651 123403 0 0 3 0x40014200 acpi0 acpi0 50027 280048 0 0 3 0x40014200 idle1 12134 365870 0 0 3 0x14200 bored softnet1 36237 250608 0 0 3 0x14200 netlock softnet0 59661 484984 0 0 2 0x14200 systqmp 17439 432512 0 0 3 0x14200 bored systq 68487 9334 0 0 3 0x14200 tmoslp softclockmp 60557 222837 0 0 3 0x40014200 tmoslp softclock 4853 347434 0 0 3 0x40014200 idle0 1 331219 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{1}> show all locks Process 39449 (syz-executor) thread 0xffff800039ff8a80 (512731) exclusive rwlock dtlk r = 0 (0xffffffff83838668) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 dt_ioctl_record_stop+0x2e sys/dev/dt/dt_dev.c:572 #3 dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] #3 dtclose+0x109 sys/dev/dt/dt_dev.c:239 #4 spec_close+0x466 sys/kern/spec_vnops.c:-1 #5 VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 #6 vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] #6 vn_closefile+0x12b sys/kern/vfs_vnops.c:615 #7 fdrop+0x121 sys/kern/kern_descrip.c:1280 #8 closef+0x192 sys/kern/kern_descrip.c:1264 #9 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #9 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 #10 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff839a7500) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 vn_closefile+0x41 sys/kern/vfs_vnops.c:608 #2 fdrop+0x121 sys/kern/kern_descrip.c:1280 #3 closef+0x192 sys/kern/kern_descrip.c:1264 #4 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #4 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 #5 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11086 12185K 13953K 166960K 13378 0 pcb 17 14K 15K 166960K 200 0 rtable 225 9K 10K 166960K 672 0 pf 37 18K 82K 166960K 270 0 ifaddr 38 7K 7K 166960K 170 0 ifgroup 59 2K 3K 166960K 324 0 sysctl 2 1K 9K 166960K 9 0 counters 72 37K 38K 166960K 312 0 ioctlops 0 0K 5K 166960K 1787 0 iov 0 0K 16K 166960K 45 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1400 88K 88K 166960K 2141 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 10 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 28 0 dirhash 12 2K 2K 166960K 18 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 244K 166960K 952 0 sigio 0 0K 0K 166960K 15 0 proc 72 115K 164K 166960K 703 0 subproc 72 4K 4K 166960K 108 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 149 0 in_multi 74 5K 6K 166960K 187 0 ether_multi 1 0K 0K 166960K 7 0 mrt 1 0K 0K 166960K 7 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 85 387K 387K 166960K 85 0 exec 0 0K 1K 166960K 584 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 277 179K 197K 166960K 10134 0 UVM aobj 12 12K 12K 166960K 12 0 pinsyscall 46 92K 104K 166960K 2185 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 38 0 NDP 13 0K 1K 166960K 104 0 temp 83 8688K 8765K 166960K 41393 0 kqueue 15 24K 32K 166960K 190 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 26 0 0 1 0 1 1 0 8 0 rtpcb 120 88 0 83 1 0 1 1 0 8 0 rtentry 176 208 0 117 5 0 5 5 0 8 0 unpcb 144 621 0 601 7 4 3 4 0 8 2 syncache 336 12 0 12 3 2 1 1 0 8 1 tcpqe 32 5 0 5 1 1 0 1 0 8 0 tcpcb 736 204 0 192 5 3 2 5 0 8 0 arp 136 30 0 14 1 0 1 1 0 8 0 inpcb 328 828 0 813 10 5 5 7 0 8 3 nd6 152 36 0 19 1 0 1 1 0 8 0 pkpcb 40 37 0 37 2 2 0 1 0 8 0 kcovpl 48 12 0 4 1 0 1 1 0 8 0 mppekey 1024 1 0 1 1 1 0 1 0 8 0 ppxss 1192 68 0 68 2 1 1 1 0 8 1 pppxif 1504 42 0 42 2 1 1 1 0 8 1 pffrag 232 12 0 9 1 0 1 1 0 482 0 pffrnode 88 12 0 9 1 0 1 1 0 8 0 pffrent 40 25 0 22 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 10 0 10 2 2 0 1 0 8 0 pfanchor 1288 15 0 12 2 1 1 1 0 8 0 pfrule 1360 13 0 7 1 0 1 1 0 8 0 rttmr 136 1 0 1 1 1 0 1 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 766 0 403 27 3 24 27 0 8 0 art_table 40 768 0 403 5 0 5 5 0 8 0 art_node 32 208 0 126 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 1 1 0 1 1 0 8 0 semapl 112 23 0 13 1 0 1 1 0 8 0 shmpl 112 4 0 0 1 0 1 1 0 8 0 dirhash 1024 21 0 4 3 0 3 3 0 8 0 dino2pl 256 3274 0 1757 96 0 96 96 0 8 0 ffsino 296 3274 0 1757 118 0 118 118 0 8 0 nchpl 144 4490 0 2776 64 0 64 64 0 8 0 rtmask 32 6 0 6 2 1 1 1 0 8 1 vnodes 216 3641 0 0 203 0 203 203 0 8 0 namei 1024 15361 0 15361 3 1 2 2 0 8 2 percpumem 16 171 0 120 1 0 1 1 0 8 0 vcpupl 3968 5 0 0 1 0 1 1 0 8 0 vmpool 848 5 0 0 1 0 1 1 0 8 0 pfiaddrpl 120 2 0 2 1 1 0 1 0 8 0 kstatmem 264 168 0 138 4 1 3 3 0 8 0 scsiplug 72 6 0 6 2 2 0 1 0 8 0 scxspl 216 28421 0 28421 10 8 2 8 1 8 2 plimitpl 152 260 0 240 1 0 1 1 0 8 0 sigapl 424 1241 0 1191 7 0 7 7 0 8 0 knotepl 120 557 0 0 17 0 17 17 0 8 0 kqueuepl 224 323 0 311 4 3 1 2 0 8 0 pipepl 344 302 0 274 9 6 3 9 0 8 0 fdescpl 528 1218 0 1185 3 0 3 3 0 8 0 filepl 160 7553 0 7316 22 8 14 17 0 8 1 lockfpl 104 344 0 340 1 0 1 1 0 8 0 lockfspl 48 122 0 118 1 0 1 1 0 8 0 sessionpl 144 34 0 24 1 0 1 1 0 8 0 pgrppl 48 59 0 41 1 0 1 1 0 8 0 ucredpl 104 1368 0 1354 1 0 1 1 0 8 0 zombiepl 144 1401 0 1399 1 0 1 1 0 8 0 processpl 1232 1241 0 1191 5 0 5 5 0 8 0 procpl 664 2558 0 2499 6 0 6 6 0 8 0 sosppl 176 6 0 6 3 2 1 1 0 8 1 sockpl 752 1585 0 1544 19 10 9 11 0 8 4 mcl64k 65536 16 0 0 2 0 2 2 0 8 0 mcl16k 16384 7 0 0 1 0 1 1 0 8 0 mcl12k 12288 5 0 0 1 0 1 1 0 8 0 mcl9k 9216 6 0 0 1 0 1 1 0 8 0 mcl8k 8192 12 0 0 2 0 2 2 0 8 0 mcl4k 4096 135 0 0 17 0 17 17 0 8 0 mcl2k 2048 26 0 0 4 0 4 4 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 1147 0 0 72 0 72 72 0 8 0 bufpl 280 12971 0 6835 439 0 439 439 0 8 0 anonpl 32 11964 0 0 97 0 97 97 0 246 0 amapchunkpl 152 33315 0 32720 42 12 30 32 0 158 4 amappl16 200 4903 0 4699 39 24 15 22 0 8 4 amappl15 192 9 0 9 1 1 0 1 0 8 0 amappl14 184 6 0 5 1 0 1 1 0 8 0 amappl13 176 465 0 463 1 0 1 1 0 8 0 amappl12 168 1623 0 1577 3 0 3 3 0 8 0 amappl11 160 5 0 5 2 2 0 1 0 8 0 amappl10 152 51 0 37 1 0 1 1 0 8 0 amappl9 144 274 0 274 1 1 0 1 0 8 0 amappl8 136 44 0 42 1 0 1 1 0 8 0 amappl7 128 94 0 93 1 0 1 1 0 8 0 amappl6 120 331 0 312 1 0 1 1 0 8 0 amappl5 112 81 0 69 1 0 1 1 0 8 0 amappl4 104 486 0 452 1 0 1 1 0 8 0 amappl3 96 5835 0 5735 3 0 3 3 0 8 0 amappl2 88 1380 0 1295 3 0 3 3 0 8 0 amappl1 80 14841 0 14133 17 0 17 17 0 8 0 amappl 88 9181 0 8996 5 0 5 5 0 92 0 uvmvnodes 80 145 0 0 3 0 3 3 0 8 0 dma4096 4096 2 0 2 2 2 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 257 0 257 3 3 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 20 0 19 1 0 1 1 0 8 0 aobjpl 72 11 0 0 1 0 1 1 0 8 0 uaddrrnd 24 1218 0 1185 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1218 0 1185 1 0 1 1 0 8 0 vmmpekpl 168 12466 0 12420 3 0 3 3 0 8 0 vmmpepl 168 87148 0 84844 116 7 109 110 0 357 2 vmsppl 488 1217 0 1185 5 0 5 5 0 8 0 rwobjpl 80 27237 0 25801 33 1 32 33 0 8 0 pdppl 4096 2454 0 2375 112 29 83 86 0 8 4 pvpl 32 22224 0 0 182 2 180 180 0 265 0 pmappl 256 1222 0 1185 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 358 0 42 10 0 10 10 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff837d3ff0) 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(ffffffff839a6d00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839a6d00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 softintr_dispatch(2) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(2) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsofttty() at Xsofttty+0x27 __mp_lock(ffffffff839a6d00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839a6d00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 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(ffffffff839a6d00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839a6d00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 ktrsyscall(ffff80003c44aa88,63,18,ffff80003c411ea0) at ktrsyscall+0x2c7 ktrwrite sys/kern/kern_ktrace.c:-1 [inline] ktrsyscall(ffff80003c44aa88,63,18,ffff80003c411ea0) at ktrsyscall+0x2c7 sys/kern/kern_ktrace.c:183 syscall(ffff80003c411ea0) at syscall+0x304 mi_syscall sys/sys/syscall_mi.h:154 [inline] syscall(ffff80003c411ea0) at syscall+0x304 sys/arch/amd64/amd64/trap.c:775 end trace frame: 0xffff80003c411f20, count: 0 ddb{0}> trace x86_ipi_db(ffffffff837d3ff0) 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(ffffffff839a6d00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839a6d00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 softintr_dispatch(2) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(2) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsofttty() at Xsofttty+0x27 __mp_lock(ffffffff839a6d00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839a6d00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 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(ffffffff839a6d00) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839a6d00) at __mp_lock+0x192 sys/kern/kern_lock.c:173 ktrsyscall(ffff80003c44aa88,63,18,ffff80003c411ea0) at ktrsyscall+0x2c7 ktrwrite sys/kern/kern_ktrace.c:-1 [inline] ktrsyscall(ffff80003c44aa88,63,18,ffff80003c411ea0) at ktrsyscall+0x2c7 sys/kern/kern_ktrace.c:183 syscall(ffff80003c411ea0) at syscall+0x304 mi_syscall sys/sys/syscall_mi.h:154 [inline] syscall(ffff80003c411ea0) at syscall+0x304 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7770cf8147d0, count: -15 ddb{0}> machine ddbcpu 1 Stopped at savectx+0xae: movl $0,%gs:0x688 savectx() at savectx+0xae end of kernel end trace frame: 0x7a4c5506ca90, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x7a4c5506ca90, count: -1