witness: lock order reversal: 1st 0xffffffff837c6e08 &cq->cq_mtx (&cq->cq_mtx) 2nd 0xffffffff838ec150 &sched_lock (&sched_lock) lock order [1] &cq->cq_mtx (&cq->cq_mtx) -> [2] &sched_lock (&sched_lock) #0 mtx_enter+0x95 sys/kern/kern_lock.c:402 #1 sleep_setup+0xc6 sys/kern/kern_synch.c:302 #2 msleep_nsec+0x10b sys/kern/kern_synch.c:217 #3 dt_ioctl_record_stop+0xbc sys/dev/dt/dt_dev.c:589 #4 dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] #4 dtclose+0x109 sys/dev/dt/dt_dev.c:239 #5 spec_close+0x466 sys/kern/spec_vnops.c:-1 #6 VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 #7 vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] #7 vn_closefile+0x12b sys/kern/vfs_vnops.c:615 #8 fdrop+0x121 sys/kern/kern_descrip.c:1280 #9 closef+0x192 sys/kern/kern_descrip.c:1264 #10 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #10 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #11 Xsyscall+0x128 lock order [2] &sched_lock (&sched_lock) -> [1] &cq->cq_mtx (&cq->cq_mtx) #0 mtx_enter+0x95 sys/kern/kern_lock.c:402 #1 clockintr_cancel+0x2f sys/kern/kern_clockintr.c:323 #2 mi_switch+0x187 sys/kern/sched_bsd.c:376 #3 sleep_finish+0x2d8 sys/kern/kern_synch.c:367 #4 sys_futex+0xb90 futex_wait sys/kern/sys_futex.c:306 [inline] #4 sys_futex+0xb90 sys/kern/sys_futex.c:155 #5 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #5 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #6 Xsyscall+0x128 Stopped at db_enter+0x25: addq $0x8,%rsp ddb{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic the kernel did not panic ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 witness_checkorder(ffffffff838ec150,9,0) at witness_checkorder+0x10d1 sys/kern/subr_witness.c:-1 mtx_enter(ffffffff838ec140) at mtx_enter+0x95 sys/kern/kern_lock.c:402 sleep_setup(ffffffff837c6e58,220,ffffffff83413c0c) at sleep_setup+0xc6 sys/kern/kern_synch.c:302 msleep_nsec(ffffffff837c6e58,ffffffff837c6df8,220,ffffffff83413c0c,ffffffffffffffff) at msleep_nsec+0x10b sys/kern/kern_synch.c:217 dt_ioctl_record_stop(ffff800001474000) at dt_ioctl_record_stop+0xbc sys/dev/dt/dt_dev.c:589 dtclose(21e5f,1,2000,ffff8000fffe87f0) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(21e5f,1,2000,ffff8000fffe87f0) at dtclose+0x109 sys/dev/dt/dt_dev.c:239 spec_close(ffff80002ebdc970) at spec_close+0x466 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8069b5cd90,1,fffffd80097fb5b0,ffff8000fffe87f0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806c082d60,ffff8000fffe87f0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806c082d60,ffff8000fffe87f0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806c082d60,ffff8000fffe87f0) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806c082d60,ffff8000fffe87f0) at closef+0x192 sys/kern/kern_descrip.c:1264 syscall(ffff80002ebdcbd0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002ebdcbd0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xf181e4e3bc0, count: -14 ddb{1}> show registers rdi 0 rsi 0x80000 acpi_pdirpa+0x6be71 rbp 0xffff80002ebdc640 rbx 0 rdx 0xffff80000144a800 rcx 0xffff8000fffe87f0 rax 0x7ffff acpi_pdirpa+0x6be70 r8 0xffff80002ebdc520 r9 0x8080808080808080 r10 0x195c99a5d9ff4a81 r11 0x8d6893bba27e6961 r12 0xfffffd8003f2ce40 r13 0xfffffd800471ad58 r14 0x3 r15 0xffffffff8340314a substchar+0xfca3 rip 0xffffffff8166e7f5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002ebdc630 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=485332 pid=55007 tcnt=2 stat=onproc flags process=0 proc=4000000 runpri=32, usrpri=86, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000fffea030,0xffff8000fffe9790 process=0xffff8000fffedcf8 user=0xffff80002ebd7000, vmspace=0xfffffd806c2119a0 estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 65378 111560 721 0 7 0 syz-executor 65378 472634 721 0 2 0x4000000 syz-executor 55007 462747 80269 0 2 0 syz-executor *55007 485332 80269 0 7 0x4000000 syz-executor 78855 495798 10789 0 3 0x80 nanoslp syz-executor 78855 373907 10789 0 3 0x4000080 kqread syz-executor 78855 285122 10789 0 3 0x4000080 fsleep syz-executor 31226 110226 50722 0 3 0x80 nanoslp syz-executor 31226 59739 50722 0 3 0x4000080 msgwait syz-executor 31226 341521 50722 0 3 0x4000080 fsleep syz-executor 44496 204774 38452 0 3 0x80 nanoslp syz-executor 44496 4248 38452 0 3 0x4000080 sbwait syz-executor 44496 441867 38452 0 3 0x4000080 fsleep syz-executor 41047 57952 91615 60929 3 0x90 nanoslp syz-executor 41047 475331 91615 60929 3 0x4000090 ttyin syz-executor 41047 226836 91615 60929 3 0x4000090 fsleep syz-executor 41047 418682 91615 60929 3 0x4000090 fsleep syz-executor 50722 426707 73242 0 3 0x82 nanoslp syz-executor 91615 374276 73242 0 3 0x82 nanoslp syz-executor 15047 16815 73242 0 3 0x82 wait syz-executor 721 398558 73242 0 3 0x82 nanoslp syz-executor 10789 519575 73242 0 3 0x82 nanoslp syz-executor 29907 98866 73242 0 3 0x82 nanoslp syz-executor 38452 213676 73242 0 3 0x82 nanoslp syz-executor 80269 125597 73242 0 3 0x82 nanoslp syz-executor 73242 519203 63479 0 3 0x82 kqread syz-executor 63479 394956 23057 0 3 0x10008a sigsusp ksh 23057 285488 36712 0 3 0x98 kqread sshd-session 36712 55988 90266 0 3 0x92 kqread sshd-session 65406 381982 1 0 3 0x100083 ttyopn getty 90266 485505 1 0 3 0x88 kqread sshd 16608 444396 27250 74 3 0x1100092 bpf pflogd 27250 13048 1 0 3 0x80 sbwait pflogd 84956 356630 24853 73 3 0x1100090 kqread syslogd 24853 47930 1 0 3 0x100082 sbwait syslogd 47785 33681 1 0 3 0x100080 kqread resolvd 84011 299845 67554 77 3 0x100092 kqread dhcpleased 80697 512398 67554 77 3 0x100092 kqread dhcpleased 67554 258276 1 0 3 0x80 kqread dhcpleased 81515 237241 0 0 3 0x14200 bored smr 11376 374358 0 0 3 0x14200 pgzero zerothread 30895 423365 0 0 3 0x14200 aiodoned aiodoned 85080 518512 0 0 3 0x14200 syncer update 1657 157991 0 0 3 0x14200 cleaner cleaner 49156 68451 0 0 3 0x14200 reaper reaper 4613 236372 0 0 3 0x14200 pgdaemon pagedaemon 1282 176721 0 0 3 0x14200 bored viomb 62557 87452 0 0 3 0x40014200 acpi0 acpi0 8240 25753 0 0 3 0x40014200 idle1 4761 110780 0 0 3 0x14200 bored softnet1 70146 476038 0 0 3 0x14200 bored softnet0 88791 157131 0 0 3 0x14200 bored systqmp 85259 48778 0 0 3 0x14200 bored systq 86264 464294 0 0 3 0x14200 tmoslp softclockmp 57772 466395 0 0 3 0x40014200 tmoslp softclock 88360 52461 0 0 3 0x40014200 idle0 1 503870 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 1: exclusive mutex &cq->cq_mtx r = 0 (0xffffffff837c6e08) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 mtx_enter+0x4b4 sys/kern/kern_lock.c:483 #2 clockintr_unbind+0x56 sys/kern/kern_clockintr.c:375 #3 dt_ioctl_record_stop+0xbc sys/dev/dt/dt_dev.c:589 #4 dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] #4 dtclose+0x109 sys/dev/dt/dt_dev.c:239 #5 spec_close+0x466 sys/kern/spec_vnops.c:-1 #6 VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 #7 vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] #7 vn_closefile+0x12b sys/kern/vfs_vnops.c:615 #8 fdrop+0x121 sys/kern/kern_descrip.c:1280 #9 closef+0x192 sys/kern/kern_descrip.c:1264 #10 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #10 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #11 Xsyscall+0x128 Process 55007 (syz-executor) thread 0xffff8000fffe87f0 (485332) exclusive rwlock dtlk r = 0 (0xffffffff838307b8) #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:765 #10 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff839231c8) #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:765 #5 Xsyscall+0x128 exclusive mutex &cq->cq_mtx r = 0 (0xffffffff837c6e08) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 mtx_enter+0x4b4 sys/kern/kern_lock.c:483 #2 clockintr_unbind+0x56 sys/kern/kern_clockintr.c:375 #3 dt_ioctl_record_stop+0xbc sys/dev/dt/dt_dev.c:589 #4 dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] #4 dtclose+0x109 sys/dev/dt/dt_dev.c:239 #5 spec_close+0x466 sys/kern/spec_vnops.c:-1 #6 VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 #7 vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] #7 vn_closefile+0x12b sys/kern/vfs_vnops.c:615 #8 fdrop+0x121 sys/kern/kern_descrip.c:1280 #9 closef+0x192 sys/kern/kern_descrip.c:1264 #10 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #10 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #11 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10229 11264K 11308K 166960K 11779 0 pcb 19 13K 13K 166960K 79 0 rtable 205 8K 8K 166960K 402 0 pf 39 18K 81K 166960K 71 0 ifaddr 40 6K 7K 166960K 55 0 ifgroup 59 2K 2K 166960K 75 0 sysctl 3 1K 9K 166960K 8 0 counters 70 37K 37K 166960K 84 0 ioctlops 0 0K 4K 166960K 1523 0 iov 0 0K 12K 166960K 8 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1408 89K 89K 166960K 1706 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 3 5K 9K 166960K 8 0 VM map 2 1K 1K 166960K 2 0 sem 4 0K 0K 166960K 69 0 dirhash 12 2K 2K 166960K 24 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 85K 166960K 387 0 sigio 0 0K 0K 166960K 5 0 proc 72 115K 164K 166960K 554 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 1 0K 0K 166960K 45 0 in_multi 89 6K 7K 166960K 117 0 ether_multi 2 0K 0K 166960K 5 0 mrt 0 0K 0K 166960K 4 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 395 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 260 161K 167K 166960K 5396 0 UVM aobj 12 2K 4K 166960K 14 0 pinsyscall 43 86K 104K 166960K 1511 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 2 0K 1K 166960K 24 0 NDP 13 0K 2K 166960K 34 0 temp 44 8653K 8717K 166960K 19771 0 kqueue 15 24K 29K 166960K 85 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 65 0 61 1 0 1 1 0 8 0 rtentry 176 113 0 27 6 0 6 6 0 8 1 unpcb 144 151 0 133 2 1 1 2 0 8 0 syncache 336 4 0 4 1 1 0 1 0 8 0 tcpcb 736 66 0 59 1 0 1 1 0 8 0 arp 136 18 0 2 1 0 1 1 0 8 0 inpcb 328 287 0 273 4 2 2 3 0 8 0 nd6 152 24 0 3 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 1 0 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1192 5 0 5 1 1 0 1 0 8 0 pffrag 232 2 0 0 1 0 1 1 0 482 0 pffrnode 88 2 0 0 1 0 1 1 0 8 0 pffrent 40 4 0 2 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 32 0 0 1 0 1 1 0 8 0 pfstkey 128 32 0 0 2 0 2 2 0 8 0 pfstate 384 30 0 0 3 0 3 3 0 8 0 pfrule 1344 22 0 17 2 1 1 2 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 489 0 122 29 2 27 29 0 8 1 art_table 40 491 0 122 5 0 5 5 0 8 0 art_node 32 113 0 36 1 0 1 1 0 8 0 sysvmsgpl 40 5 0 3 1 0 1 1 0 8 0 semapl 112 67 0 65 1 0 1 1 0 8 0 shmpl 112 11 0 2 1 0 1 1 0 8 0 dirhash 1024 26 0 9 3 0 3 3 0 8 0 dino2pl 256 2033 0 521 96 0 96 96 0 8 0 ffsino 296 2033 0 521 118 0 118 118 0 8 0 nchpl 144 2562 0 862 64 0 64 64 0 8 0 rtmask 32 1 0 1 1 1 0 1 0 8 0 vnodes 216 2377 0 0 133 0 133 133 0 8 0 namei 1024 8454 0 8454 2 1 1 2 0 8 1 percpumem 16 57 0 7 1 0 1 1 0 8 0 kstatmem 264 40 0 10 3 1 2 3 0 8 0 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 2 0 2 1 1 0 1 0 8 0 scxspl 216 9276 0 9276 8 7 1 6 1 8 1 plimitpl 152 62 0 43 1 0 1 1 0 8 0 sigapl 424 695 0 647 6 0 6 6 0 8 0 knotepl 120 313 0 0 10 0 10 10 0 8 0 kqueuepl 224 122 0 110 3 2 1 3 0 8 0 pipepl 344 142 0 114 3 0 3 3 0 8 0 fdescpl 528 679 0 647 3 0 3 3 0 8 0 filepl 160 3293 0 3058 18 5 13 15 0 8 3 lockfpl 104 108 0 104 1 0 1 1 0 8 0 lockfspl 48 54 0 50 1 0 1 1 0 8 0 sessionpl 144 22 0 13 1 0 1 1 0 8 0 pgrppl 48 36 0 19 1 0 1 1 0 8 0 ucredpl 104 332 0 318 1 0 1 1 0 8 0 zombiepl 144 649 0 647 1 0 1 1 0 8 0 processpl 1232 695 0 647 5 1 4 5 0 8 0 procpl 664 1124 0 1065 7 1 6 6 0 8 0 sosppl 176 1 0 1 1 1 0 1 0 8 0 sockpl 752 509 0 473 7 3 4 6 0 8 0 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 129 0 0 17 0 17 17 0 8 0 mcl2k 2048 26 0 0 4 0 4 4 0 8 0 mtagpl 96 3 0 0 1 0 1 1 0 8 0 mbufpl 256 150 0 0 10 0 10 10 0 8 0 bufpl 280 3280 0 130 225 0 225 225 0 8 0 anonpl 32 9406 0 0 76 0 76 76 0 246 0 amapchunkpl 152 16853 0 16187 34 7 27 28 0 158 0 amappl16 200 2672 0 2645 17 12 5 15 0 8 0 amappl15 192 7 0 7 1 1 0 1 0 8 0 amappl14 184 18 0 18 1 1 0 1 0 8 0 amappl13 176 427 0 426 1 0 1 1 0 8 0 amappl12 168 1071 0 1027 3 0 3 3 0 8 0 amappl11 160 5 0 5 1 1 0 1 0 8 0 amappl10 152 45 0 31 1 0 1 1 0 8 0 amappl9 144 247 0 247 1 1 0 1 0 8 0 amappl8 136 55 0 53 1 0 1 1 0 8 0 amappl7 128 88 0 86 1 0 1 1 0 8 0 amappl6 120 280 0 267 1 0 1 1 0 8 0 amappl5 112 81 0 71 1 0 1 1 0 8 0 amappl4 104 422 0 390 1 0 1 1 0 8 0 amappl3 96 2766 0 2663 4 1 3 3 0 8 0 amappl2 88 783 0 704 2 0 2 2 0 8 0 amappl1 80 10020 0 9418 14 1 13 14 0 8 0 amappl 88 4618 0 4437 5 0 5 5 0 92 0 uvmvnodes 80 111 0 0 3 0 3 3 0 8 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 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 13 0 2 1 0 1 1 0 8 0 uaddrrnd 24 679 0 647 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 679 0 647 1 0 1 1 0 8 0 vmmpekpl 168 7160 0 7127 2 0 2 2 0 8 0 vmmpepl 168 50261 0 48268 97 9 88 97 0 357 0 vmsppl 488 678 0 647 5 1 4 5 0 8 0 rwobjpl 80 16697 0 15626 27 1 26 27 0 8 0 pdppl 4096 1366 0 1294 100 28 72 82 0 8 0 pvpl 32 16211 0 0 131 0 131 131 0 265 0 pmappl 256 678 0 647 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 274 0 34 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp ddb{0}> trace x86_ipi_db(ffffffff837c5ff0) 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 mtx_enter(ffffffff837c6df8) at mtx_enter+0x377 sys/kern/kern_lock.c:450 clockintr_dispatch(ffff80003c42ae80) at clockintr_dispatch+0x401 sys/kern/kern_clockintr.c:215 lapic_clockintr(0,0) at lapic_clockintr+0x51 sys/arch/amd64/amd64/lapic.c:484 Xresume_lapic_ltimer() at Xresume_lapic_ltimer+0x2a end of kernel end trace frame: 0x7e2a33954120, count: -7 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x25: addq $0x8,%rsp ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 witness_checkorder(ffffffff838ec150,9,0) at witness_checkorder+0x10d1 sys/kern/subr_witness.c:-1 mtx_enter(ffffffff838ec140) at mtx_enter+0x95 sys/kern/kern_lock.c:402 sleep_setup(ffffffff837c6e58,220,ffffffff83413c0c) at sleep_setup+0xc6 sys/kern/kern_synch.c:302 msleep_nsec(ffffffff837c6e58,ffffffff837c6df8,220,ffffffff83413c0c,ffffffffffffffff) at msleep_nsec+0x10b sys/kern/kern_synch.c:217 dt_ioctl_record_stop(ffff800001474000) at dt_ioctl_record_stop+0xbc sys/dev/dt/dt_dev.c:589 dtclose(21e5f,1,2000,ffff8000fffe87f0) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(21e5f,1,2000,ffff8000fffe87f0) at dtclose+0x109 sys/dev/dt/dt_dev.c:239 spec_close(ffff80002ebdc970) at spec_close+0x466 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8069b5cd90,1,fffffd80097fb5b0,ffff8000fffe87f0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806c082d60,ffff8000fffe87f0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806c082d60,ffff8000fffe87f0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806c082d60,ffff8000fffe87f0) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806c082d60,ffff8000fffe87f0) at closef+0x192 sys/kern/kern_descrip.c:1264 syscall(ffff80002ebdcbd0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002ebdcbd0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xf181e4e3bc0, count: -14