uvm_fault(0xfffffd8071fc0d70, 0x0, 0, 1) -> e fatal page fault in supervisor mode trap type 6 code 0 rip ffffffff81577d98 cs 8 rflags 10207 cr2 0 cpl 0 rsp ffff8000384219f0 gsbase 0xffff8000299edff0 kgsbase 0x0 panic: trap type 6, code=0, pc=ffffffff81577d98 Starting stack trace... panic(ffffffff833a20e5) at panic+0x1d0 sys/kern/subr_prf.c:229 kerntrap(ffff800038421940) at kerntrap+0x30b alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dt_ioctl_record_stop(ffff80000148b000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:586 dtclose(31e5f,81,2000,ffff80002a2e5778) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(31e5f,81,2000,ffff80002a2e5778) at dtclose+0x109 sys/dev/dt/dt_dev.c:232 spec_close(ffff800038421af0) at spec_close+0x466 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806a376cf0,81,fffffd80097fb410,ffff80002a2e5778) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b90d5f8,ffff80002a2e5778) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b90d5f8,ffff80002a2e5778) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806b90d5f8,ffff80002a2e5778) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806b90d5f8,ffff80002a2e5778) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80002a2e5778) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80002a2e5778,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80002a2e5778,ffff800038421e60,ffff800038421db0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff800038421e60) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800038421e60) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:746 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x79efdcef3510, count: 242 End of stack trace. WARNING: SPL NOT LOWERED ON SYSCALL 252 0 EXIT 0 4 Stopped at savectx+0xae: movl $0,%gs:0x688 TID PID UID PRFLAGS PFLAGS CPU COMMAND 496134 66555 0 0 0x4000000 0 syz-executor *393423 91820 0 0 0x4000000 1 syz-executor savectx() at savectx+0xae end of kernel end trace frame: 0x426d45e6070, 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(0xfffffd8071fc0d70, 0x0, 0, 1) -> e ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x426d45e6070, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff800039839170 rbx 0 rdx 0xffff80000147e280 rcx 0xffff80002a2e4fb0 rax 0x33 r8 0xffff8000398390a0 r9 0x1 r10 0xe8a6c0c5fddc13aa r11 0x76dcb1a24924bddf r12 0 r13 0 r14 0xffff80002a2e4fb0 r15 0 rip 0xffffffff813a73ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff8000398390f0 ss 0x10 savectx+0xae: movl $0,%gs:0x688 ddb{1}> show proc PROC (syz-executor) tid=393423 pid=91820 tcnt=3 stat=onproc flags process=0 proc=4000000 runpri=50, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a2e4d18,0xffff8000ffff3778 process=0xffff8000384249c0 user=0xffff800039834000, vmspace=0xfffffd8071fc07b8 estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 66555 47249 1268 0 2 0 syz-executor 66555 496134 1268 0 7 0x4000000 syz-executor 91820 170194 52574 0 2 0 syz-executor *91820 393423 52574 0 7 0x4000000 syz-executor 91820 198484 52574 0 3 0x4000080 fsleep syz-executor 56450 485899 15644 0 3 0x80 nanoslp syz-executor 56450 463185 15644 0 3 0x4000080 kqread syz-executor 56450 28801 15644 0 3 0x4000080 fsleep syz-executor 84867 246211 81772 0 2 0 syz-executor 84867 460149 81772 0 3 0x4000080 kqpoll syz-executor 27406 438148 94831 0 3 0x80 nanoslp syz-executor 27406 117645 94831 0 3 0x4000080 ttyout syz-executor 27406 270093 94831 0 3 0x4000080 fsleep syz-executor 27406 452070 94831 0 3 0x4000080 ttyout syz-executor 52574 47077 81825 0 3 0x82 nanoslp syz-executor 50015 370621 81825 0 3 0x82 nanoslp syz-executor 81772 126067 81825 0 3 0x82 nanoslp syz-executor 15644 160660 81825 0 3 0x82 nanoslp syz-executor 94831 515457 81825 0 3 0x82 nanoslp syz-executor 1268 62026 81825 0 3 0x82 nanoslp syz-executor 55837 446785 81825 0 3 0x82 wait syz-executor 73620 261279 81825 0 3 0x2 biowait syz-executor 81825 298511 57280 0 3 0x82 kqread syz-executor 57280 371805 40435 0 3 0x10008a sigsusp ksh 40435 275544 62639 0 3 0x98 kqread sshd-session 62639 187748 43643 0 3 0x92 kqread sshd-session 95251 288855 1 0 3 0x100083 ttyin getty 43643 464555 1 0 3 0x88 kqread sshd 7133 202258 85193 74 3 0x1100092 bpf pflogd 85193 397821 1 0 3 0x80 sbwait pflogd 80355 238262 56526 73 3 0x1100090 kqread syslogd 56526 230056 1 0 3 0x100082 sbwait syslogd 59694 178999 1 0 3 0x100080 kqread resolvd 66775 166703 10876 77 3 0x100092 kqread dhcpleased 80175 73032 10876 77 3 0x100092 kqread dhcpleased 10876 321734 1 0 3 0x80 kqread dhcpleased 41307 294517 0 0 3 0x14200 bored smr 77482 490981 0 0 2 0x14200 zerothread 23329 208716 0 0 3 0x14200 aiodoned aiodoned 59469 212362 0 0 3 0x14200 syncer update 36268 362739 0 0 3 0x14200 cleaner cleaner 55564 57996 0 0 3 0x14200 reaper reaper 21434 329615 0 0 3 0x14200 pgdaemon pagedaemon 16658 93753 0 0 3 0x14200 bored viomb 27972 237341 0 0 3 0x40014200 acpi0 acpi0 83305 281740 0 0 3 0x40014200 idle1 36190 437009 0 0 3 0x14200 bored softnet7 12376 161569 0 0 3 0x14200 bored softnet6 78871 300730 0 0 3 0x14200 bored softnet5 42389 178114 0 0 3 0x14200 bored softnet4 79094 54529 0 0 3 0x14200 bored softnet3 21313 167416 0 0 3 0x14200 bored softnet2 58411 523187 0 0 3 0x14200 bored softnet1 96594 106253 0 0 3 0x14200 netlock softnet0 48481 303333 0 0 2 0x40014200 systqmp 99786 316046 0 0 3 0x14200 bored systq 38097 312538 0 0 3 0x14200 tmoslp softclockmp 71284 88010 0 0 3 0x40014200 tmoslp softclock 8656 459653 0 0 3 0x40014200 idle0 1 160807 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 73620 (syz-executor) thread 0xffff80002a2c27e0 (261279) exclusive rrwlock inode r = 0 (0xfffffd806b6ceec0) #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 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 #4 ufs_ihashins+0x4f ufs_ihash sys/ufs/ufs/ufs_ihash.c:-1 [inline] #4 ufs_ihashins+0x4f sys/ufs/ufs/ufs_ihash.c:159 #5 ffs_vget+0x187 sys/ufs/ffs/ffs_vfsops.c:1232 #6 ffs_inode_alloc+0x279 sys/ufs/ffs/ffs_alloc.c:393 #7 ufs_mkdir+0xfc sys/ufs/ufs/ufs_vnops.c:1112 #8 VOP_MKDIR+0x101 sys/kern/vfs_vops.c:394 #9 domkdirat+0x179 sys/kern/vfs_syscalls.c:3113 #10 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #10 syscall+0xb17 sys/arch/amd64/amd64/trap.c:746 #11 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806ccb3b30) #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 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #5 vfs_lookup+0x11c sys/kern/vfs_lookup.c:-1 #6 namei+0x7ca sys/kern/vfs_lookup.c:250 #7 domkdirat+0x8b sys/kern/vfs_syscalls.c:3098 #8 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xb17 sys/arch/amd64/amd64/trap.c:746 #9 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10210 11048K 11163K 166960K 11415 0 pcb 17 12K 12K 166960K 28 0 rtable 201 5K 6K 166960K 262 0 pf 36 17K 18K 166960K 49 0 ifaddr 43 7K 7K 166960K 47 0 ifgroup 57 2K 2K 166960K 61 0 sysctl 3 1K 9K 166960K 8 0 counters 70 37K 37K 166960K 72 0 ioctlops 0 0K 4K 166960K 1528 0 iov 0 0K 0K 166960K 1 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1397 88K 88K 166960K 1465 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 3 5K 9K 166960K 4 0 VM map 2 1K 1K 166960K 2 0 sem 4 0K 0K 166960K 5 0 dirhash 12 2K 2K 166960K 12 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 102K 166960K 202 0 sigio 0 0K 0K 166960K 4 0 proc 72 115K 164K 166960K 543 0 subproc 72 4K 4K 166960K 72 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 2 0K 0K 166960K 67 0 in_multi 99 7K 7K 166960K 102 0 ether_multi 1 0K 0K 166960K 2 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 79 360K 360K 166960K 79 0 exec 0 0K 1K 166960K 369 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 241 152K 159K 166960K 3470 0 UVM aobj 4 2K 2K 166960K 4 0 pinsyscall 42 84K 103K 166960K 1283 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 2 0K 0K 166960K 6 0 NDP 13 0K 2K 166960K 30 0 temp 37 8642K 8707K 166960K 4514 0 kqueue 17 28K 28K 166960K 35 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 39 0 36 1 0 1 1 0 8 0 rtentry 176 96 0 4 5 0 5 5 0 8 0 unpcb 144 53 0 35 1 0 1 1 0 8 0 syncache 336 3 0 3 1 0 1 1 0 8 1 tcpcb 736 19 0 15 1 0 1 1 0 8 0 arp 136 11 0 1 1 0 1 1 0 8 0 inpcb 328 104 0 91 2 0 2 2 0 8 0 nd6 144 16 0 0 1 0 1 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1192 1 0 0 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 pfstitem 24 17 0 0 1 0 1 1 0 8 0 pfstkey 128 17 0 0 1 0 1 1 0 8 0 pfstate 384 17 0 0 2 0 2 2 0 8 0 pfrule 1344 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 438 0 3 28 0 28 28 0 8 0 art_table 40 439 0 3 5 0 5 5 0 8 0 art_node 32 96 0 14 1 0 1 1 0 8 0 sysvmsgpl 40 1 0 1 1 0 1 1 0 8 1 semapl 112 3 0 1 1 0 1 1 0 8 0 shmpl 112 1 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1675 0 161 95 0 95 95 0 8 0 ffsino 296 1675 0 161 117 0 117 117 0 8 0 nchpl 144 1944 0 251 63 0 63 63 0 8 0 uvmvnodes 80 1839 0 0 38 0 38 38 0 8 0 vnodes 216 1839 0 0 103 0 103 103 0 8 0 namei 1024 6097 0 6096 1 0 1 1 0 8 0 percpumem 16 51 0 1 1 0 1 1 0 8 0 kstatmem 264 30 0 2 2 0 2 2 0 8 0 scxspl 216 7092 0 7090 3 1 2 2 1 8 1 plimitpl 152 70 0 52 1 0 1 1 0 8 0 sigapl 424 500 0 447 7 0 7 7 0 8 0 knotepl 120 286 0 0 9 0 9 9 0 8 0 kqueuepl 224 42 0 26 1 0 1 1 0 8 0 pipepl 344 106 0 79 3 0 3 3 0 8 0 fdescpl 528 478 0 447 3 0 3 3 0 8 0 filepl 160 1939 0 1709 12 0 12 12 0 8 2 lockfpl 104 20 0 18 1 0 1 1 0 8 0 lockfspl 48 11 0 9 1 0 1 1 0 8 0 sessionpl 144 22 0 13 1 0 1 1 0 8 0 pgrppl 48 32 0 15 1 0 1 1 0 8 0 ucredpl 104 167 0 154 1 0 1 1 0 8 0 zombiepl 144 449 0 447 1 0 1 1 0 8 0 processpl 1232 500 0 447 5 0 5 5 0 8 0 procpl 664 617 0 555 6 0 6 6 0 8 0 sockpl 752 197 0 163 4 0 4 4 0 8 0 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 106 0 0 14 0 14 14 0 8 0 mcl2k 2048 31 0 0 4 0 4 4 0 8 0 mtagpl 96 3 0 0 1 0 1 1 0 8 0 mbufpl 256 133 0 0 9 0 9 9 0 8 0 bufpl 280 3123 0 118 215 0 215 215 0 8 0 anonpl 32 5431 0 0 44 0 44 44 0 246 0 amapchunkpl 152 10305 0 9673 27 2 25 25 0 158 0 amappl16 200 2167 0 2145 5 1 4 5 0 8 1 amappl15 192 4 0 4 1 1 0 1 0 8 0 amappl14 184 114 0 102 1 0 1 1 0 8 0 amappl13 176 9 0 7 1 0 1 1 0 8 0 amappl12 168 1122 0 1091 4 1 3 3 0 8 0 amappl11 160 48 0 34 1 0 1 1 0 8 0 amappl10 152 7 0 7 1 1 0 1 0 8 0 amappl9 144 259 0 259 1 1 0 1 0 8 0 amappl8 136 21 0 19 1 0 1 1 0 8 0 amappl7 128 108 0 96 1 0 1 1 0 8 0 amappl6 120 179 0 176 1 0 1 1 0 8 0 amappl5 112 123 0 114 1 0 1 1 0 8 0 amappl4 104 294 0 273 1 0 1 1 0 8 0 amappl3 96 1590 0 1490 4 1 3 3 0 8 0 amappl2 88 704 0 626 2 0 2 2 0 8 0 amappl1 80 8396 0 7797 16 1 15 15 0 8 1 amappl 88 2783 0 2613 5 0 5 5 0 92 1 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 6 0 6 1 1 0 1 0 8 0 dma128 128 253 0 253 1 1 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 18 0 17 1 0 1 1 0 8 0 aobjpl 72 3 0 0 1 0 1 1 0 8 0 uaddrrnd 24 478 0 447 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 478 0 447 1 0 1 1 0 8 0 vmmpekpl 168 5482 0 5456 2 0 2 2 0 8 0 vmmpepl 168 36975 0 35021 90 0 90 90 0 357 2 vmsppl 488 477 0 447 5 0 5 5 0 8 0 rwobjpl 80 15129 0 12361 57 0 57 57 0 8 0 pdppl 4096 964 0 894 100 28 72 86 0 8 2 pvpl 32 12973 0 0 105 0 105 105 0 265 0 pmappl 256 477 0 447 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 266 0 30 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff8379dff0) 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 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c kd_curproc sys/dev/kcov.c:584 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c sys/dev/kcov.c:153 __mp_lock(ffffffff83892960) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83892960) at __mp_lock+0x1a3 sys/kern/kern_lock.c:165 softintr_dispatch(2) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(2) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:847 Xsofttty() at Xsofttty+0x27 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x44 sys/dev/kcov.c:159 intr_handler(ffff80003942d490,ffff800000079a80) at intr_handler+0xe9 sys/arch/amd64/amd64/intr.c:559 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x33 kd_curproc sys/dev/kcov.c:585 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x33 sys/dev/kcov.c:153 __mp_lock(ffffffff83892960) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83892960) at __mp_lock+0x1a3 sys/kern/kern_lock.c:165 syscall(ffff80003942d670) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] syscall(ffff80003942d670) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:746 end trace frame: 0xffff80003942d6f0, count: 0 ddb{0}> trace x86_ipi_db(ffffffff8379dff0) 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 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c kd_curproc sys/dev/kcov.c:584 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c sys/dev/kcov.c:153 __mp_lock(ffffffff83892960) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83892960) at __mp_lock+0x1a3 sys/kern/kern_lock.c:165 softintr_dispatch(2) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(2) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:847 Xsofttty() at Xsofttty+0x27 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x44 sys/dev/kcov.c:159 intr_handler(ffff80003942d490,ffff800000079a80) at intr_handler+0xe9 sys/arch/amd64/amd64/intr.c:559 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x33 kd_curproc sys/dev/kcov.c:585 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x33 sys/dev/kcov.c:153 __mp_lock(ffffffff83892960) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83892960) at __mp_lock+0x1a3 sys/kern/kern_lock.c:165 syscall(ffff80003942d670) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] syscall(ffff80003942d670) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:746 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xabe74b49930, 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: 0x426d45e6070, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x426d45e6070, count: -1