panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 953 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 233100 84983 0 0 0 1 syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8336cc85) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833afb80,ffffffff833c13bf,3b9,ffffffff833eb28e) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff8000344174e8,ffffffff83365c16) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(205b9a,ffff8000344174e0) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,83,2000,ffff80003c444d20) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003701f140) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806b80b870,83,fffffd80097fb4e0,ffff80003c444d20) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b8cca40,ffff80003c444d20) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b8cca40,ffff80003c444d20) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806b8cca40,ffff80003c444d20) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806b8cca40,ffff80003c444d20) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80003c444d20) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80003c444d20,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c444d20,ffff80003701f4b0,ffff80003701f400) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80003701f4a0, count: 0 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic *cpu0: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 953 ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8336cc85) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833afb80,ffffffff833c13bf,3b9,ffffffff833eb28e) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff8000344174e8,ffffffff83365c16) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(205b9a,ffff8000344174e0) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,83,2000,ffff80003c444d20) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003701f140) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806b80b870,83,fffffd80097fb4e0,ffff80003c444d20) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b8cca40,ffff80003c444d20) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b8cca40,ffff80003c444d20) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806b8cca40,ffff80003c444d20) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806b8cca40,ffff80003c444d20) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80003c444d20) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80003c444d20,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c444d20,ffff80003701f4b0,ffff80003701f400) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003701f4b0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003701f4b0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7946230faa70, count: -16 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80003701ef10 rbx 0xffffffff837e1ddf cpu_info_full_primary+0x2ddf rdx 0 rcx 0xffff80003c444d20 rax 0xffffffff837e0ff0 cpu_info_full_primary+0x1ff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xbac289bdd919aa26 r11 0x39bbe9a317b7626e r12 0xffffffff837e1be0 cpu_info_full_primary+0x2be0 r13 0 r14 0 r15 0x1 rip 0xffffffff831f1095 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003701ef00 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=492837 pid=44742 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=32, usrpri=80, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff80003c444d20 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff80003c4447f0,0xffff80003c444fc8 process=0xffff80003a0366a0 user=0xffff80003701a000, vmspace=0xfffffd806b8863f0 estcpu=36, cpticks=2, pctcpu=0.0, user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 84983 233100 90839 0 7 0 syz-executor 98397 152732 69982 0 2 0 syz-executor 98397 259793 69982 0 3 0x4000080 fsleep syz-executor 20588 37095 6905 0 2 0 syz-executor 20588 173550 6905 0 3 0x4000080 kqsel syz-executor 20588 194179 6905 0 2 0x4000000 syz-executor 3105 393778 13653 0 2 0 syz-executor 3105 256960 13653 0 3 0x4000080 fsleep syz-executor 3105 116597 13653 0 3 0x4000080 fsleep syz-executor 3105 500233 13653 0 3 0x4000080 fsleep syz-executor 4413 158948 5613 0 2 0 syz-executor 4413 289805 5613 0 3 0x4000000 smrbar syz-executor 4413 498132 5613 0 3 0x4000080 fsleep syz-executor 32108 505967 0 0 3 0x14200 bored sosplice 40742 42989 76447 0 2 0x2 syz-executor 69982 72993 76447 0 3 0x82 nanoslp syz-executor 13653 212957 76447 0 2 0xc82 syz-executor 6905 113812 76447 0 2 0xc82 syz-executor 90839 411536 76447 0 3 0x82 nanoslp syz-executor 37156 67666 76447 0 2 0xc82 syz-executor 5613 427661 76447 0 3 0x82 nanoslp syz-executor 3791 76994 76447 0 2 0xc82 syz-executor 76447 408906 82328 0 3 0x82 kqread syz-executor 82328 319995 60715 0 3 0x10008a sigsusp ksh 60715 379775 70787 0 3 0x98 kqread sshd-session 70787 1767 84131 0 3 0x92 kqread sshd-session 94225 503303 1 0 3 0x100083 ttyin getty 84131 349124 1 0 3 0x88 kqread sshd 63418 13931 66392 74 3 0x1100092 bpf pflogd 66392 37731 1 0 3 0x80 sbwait pflogd 60514 47156 95342 73 3 0x1100090 kqread syslogd 95342 237290 1 0 3 0x100082 sbwait syslogd 91239 47725 1 0 3 0x100080 kqread resolvd 99743 456355 22065 77 3 0x100092 kqread dhcpleased 73179 130366 22065 77 3 0x100092 kqread dhcpleased 22065 246598 1 0 3 0x80 kqread dhcpleased 39242 157657 0 0 3 0x14200 bored smr 33652 228237 0 0 2 0x14200 zerothread 24500 401872 0 0 3 0x14200 aiodoned aiodoned 22375 337616 0 0 3 0x14200 syncer update 61398 511425 0 0 3 0x14200 cleaner cleaner 26615 326485 0 0 3 0x14200 reaper reaper 80634 356577 0 0 3 0x14200 pgdaemon pagedaemon 95520 200522 0 0 3 0x14200 bored viomb 65198 148716 0 0 3 0x40014200 acpi0 acpi0 26029 254097 0 0 3 0x40014200 idle1 77463 71249 0 0 3 0x14200 bored softnet7 71292 425846 0 0 3 0x14200 bored softnet6 39121 389610 0 0 3 0x14200 bored softnet5 64093 35101 0 0 3 0x14200 bored softnet4 49255 297653 0 0 3 0x14200 bored softnet3 65120 52795 0 0 3 0x14200 bored softnet2 73512 467326 0 0 3 0x14200 bored softnet1 9638 179515 0 0 3 0x14200 bored softnet0 61786 14604 0 0 3 0x14200 bored systqmp 9761 399035 0 0 3 0x14200 bored systq 6779 291418 0 0 3 0x14200 tmoslp softclockmp 88895 262901 0 0 2 0x40014200 softclock 1261 478256 0 0 3 0x40014200 idle0 1 357920 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{0}> show all locks Process 20588 (syz-executor) thread 0xffff800034418d18 (194179) exclusive rrwlock inode r = 0 (0xfffffd806b7a4330) #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 vn_write+0x18f sys/kern/vfs_vnops.c:405 #6 dofilewritev+0x242 sys/kern/sys_generic.c:380 #7 sys_write+0xa2 sys/kern/sys_generic.c:300 #8 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:748 #9 Xsyscall+0x128 Process 40742 (syz-executor) thread 0xffff8000ffff27d8 (42989) exclusive rrwlock inode r = 0 (0xfffffd806bcc2c68) #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:748 #11 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806bcc2328) #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:748 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10217 11219K 11320K 166960K 11505 0 pcb 17 12K 12K 166960K 31 0 rtable 207 8K 8K 166960K 293 0 pf 37 18K 18K 166960K 77 0 ifaddr 42 7K 7K 166960K 57 0 ifgroup 58 2K 2K 166960K 81 0 sysctl 3 1K 9K 166960K 8 0 counters 72 37K 37K 166960K 102 0 ioctlops 0 0K 4K 166960K 1514 0 iov 0 0K 32K 166960K 11 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1410 89K 89K 166960K 1586 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 1K 166960K 2 0 VM map 2 1K 1K 166960K 2 0 sem 5 0K 0K 166960K 9 0 dirhash 12 2K 2K 166960K 15 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 85K 166960K 304 0 sigio 0 0K 0K 166960K 4 0 proc 72 115K 164K 166960K 545 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 0 0K 0K 166960K 18 0 in_multi 89 6K 7K 166960K 100 0 ether_multi 1 0K 0K 166960K 1 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 67 307K 307K 166960K 67 0 exec 0 0K 1K 166960K 381 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 226 159K 168K 166960K 4402 0 UVM aobj 5 2K 2K 166960K 6 0 pinsyscall 42 84K 101K 166960K 1387 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 13 0 NDP 13 0K 2K 166960K 37 0 temp 40 8639K 8703K 166960K 9386 0 kqueue 14 22K 28K 166960K 67 0 SYN cache 2 16K 16K 166960K 2 0 ddb{0}> 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 50 0 47 1 0 1 1 0 8 0 rtentry 176 98 0 10 5 0 5 5 0 8 0 unpcb 144 359 0 341 3 0 3 3 0 8 1 syncache 336 4 0 4 1 0 1 1 0 8 1 tcpcb 736 53 0 48 1 0 1 1 0 8 0 arp 128 10 0 1 1 0 1 1 0 8 0 inpcb 328 173 0 164 2 0 2 2 0 8 1 nd6 144 17 0 2 1 0 1 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1192 15 0 13 1 0 1 1 0 8 0 pppxif 1504 2 0 1 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 19 0 0 1 0 1 1 0 8 0 pfstkey 128 19 0 0 1 0 1 1 0 8 0 pfstate 384 19 0 0 2 0 2 2 0 8 0 pfrule 1344 25 0 20 2 1 1 2 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 444 0 42 28 0 28 28 0 8 2 art_table 40 446 0 42 5 0 5 5 0 8 0 art_node 32 98 0 19 1 0 1 1 0 8 0 sysvmsgpl 40 5 0 4 1 0 1 1 0 8 0 semapl 112 7 0 4 1 0 1 1 0 8 0 shmpl 112 3 0 1 1 0 1 1 0 8 0 dirhash 1024 19 0 2 3 0 3 3 0 8 0 dino2pl 256 1896 0 379 95 0 95 95 0 8 0 ffsino 296 1896 0 379 117 0 117 117 0 8 0 nchpl 144 2321 0 627 63 0 63 63 0 8 0 rtmask 32 6 0 6 1 0 1 1 0 8 1 uvmvnodes 80 2141 0 0 44 0 44 44 0 8 0 vnodes 216 2141 0 0 119 0 119 119 0 8 0 namei 1024 7456 0 7455 2 0 2 2 0 8 1 percpumem 16 66 0 15 1 0 1 1 0 8 0 kstatmem 264 44 0 16 2 0 2 2 0 8 0 scsiplug 72 3 0 3 1 0 1 1 0 8 1 scxspl 216 10300 0 10300 3 2 1 2 1 8 1 plimitpl 152 114 0 96 1 0 1 1 0 8 0 sigapl 424 610 0 556 7 0 7 7 0 8 0 knotepl 120 504 0 0 16 0 16 16 0 8 0 kqueuepl 224 91 0 77 2 0 2 2 0 8 0 pipepl 344 123 0 96 3 0 3 3 0 8 0 fdescpl 528 585 0 554 3 0 3 3 0 8 0 filepl 160 2839 0 2615 14 0 14 14 0 8 4 lockfpl 104 59 0 55 1 0 1 1 0 8 0 lockfspl 48 29 0 25 1 0 1 1 0 8 0 sessionpl 144 23 0 14 1 0 1 1 0 8 0 pgrppl 48 34 0 17 1 0 1 1 0 8 0 ucredpl 104 307 0 294 1 0 1 1 0 8 0 zombiepl 144 558 0 556 1 0 1 1 0 8 0 processpl 1232 610 0 556 5 0 5 5 0 8 0 procpl 664 917 0 855 7 0 7 7 0 8 0 sockpl 752 585 0 555 7 0 7 7 0 8 3 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 108 0 0 14 0 14 14 0 8 0 mcl2k 2048 19 0 0 3 0 3 3 0 8 0 mtagpl 96 3 0 0 1 0 1 1 0 8 0 mbufpl 256 130 0 0 9 0 9 9 0 8 0 bufpl 280 4421 0 122 308 0 308 308 0 8 0 anonpl 32 6941 0 0 56 0 56 56 0 246 0 amapchunkpl 152 13376 0 12918 27 3 24 24 0 158 3 amappl16 200 2375 0 2341 12 1 11 11 0 8 6 amappl15 192 20 0 20 1 1 0 1 0 8 0 amappl14 184 112 0 100 1 0 1 1 0 8 0 amappl13 176 8 0 7 1 0 1 1 0 8 0 amappl12 168 1228 0 1197 4 1 3 3 0 8 1 amappl11 160 55 0 41 1 0 1 1 0 8 0 amappl10 152 3 0 3 1 1 0 1 0 8 0 amappl9 144 253 0 253 1 1 0 1 0 8 0 amappl8 136 19 0 17 1 0 1 1 0 8 0 amappl7 128 112 0 99 1 0 1 1 0 8 0 amappl6 120 181 0 178 1 0 1 1 0 8 0 amappl5 112 123 0 113 1 0 1 1 0 8 0 amappl4 104 300 0 282 1 0 1 1 0 8 0 amappl3 96 2409 0 2303 5 1 4 4 0 8 0 amappl2 88 640 0 577 2 0 2 2 0 8 0 amappl1 80 9047 0 8435 15 0 15 15 0 8 0 amappl 88 3709 0 3555 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 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 5 0 1 1 0 1 1 0 8 0 uaddrrnd 24 585 0 554 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 585 0 554 1 0 1 1 0 8 0 vmmpekpl 168 6419 0 6384 2 0 2 2 0 8 0 vmmpepl 168 43575 0 41604 97 0 97 97 0 357 5 vmsppl 488 584 0 554 5 0 5 5 0 8 1 rwobjpl 80 16907 0 13836 65 0 65 65 0 8 0 pdppl 4096 1178 0 1108 96 24 72 84 0 8 2 pvpl 32 15407 0 0 126 1 125 125 0 265 0 pmappl 256 584 0 554 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 262 0 26 8 0 8 8 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff8336cc85) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833afb80,ffffffff833c13bf,3b9,ffffffff833eb28e) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff8000344174e8,ffffffff83365c16) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(205b9a,ffff8000344174e0) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,83,2000,ffff80003c444d20) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003701f140) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd806b80b870,83,fffffd80097fb4e0,ffff80003c444d20) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b8cca40,ffff80003c444d20) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b8cca40,ffff80003c444d20) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806b8cca40,ffff80003c444d20) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806b8cca40,ffff80003c444d20) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80003c444d20) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80003c444d20,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c444d20,ffff80003701f4b0,ffff80003701f400) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003701f4b0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003701f4b0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7946230faa70, count: -16 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffff8000299fdff0) 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(ffffffff83940f38) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83940f38) at __mp_lock+0x192 sys/kern/kern_lock.c:165 syscall(ffff80003c469330) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] syscall(ffff80003c469330) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x745345813310, count: 9 ddb{1}> trace x86_ipi_db(ffff8000299fdff0) 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(ffffffff83940f38) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83940f38) at __mp_lock+0x192 sys/kern/kern_lock.c:165 syscall(ffff80003c469330) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] syscall(ffff80003c469330) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:748 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x745345813310, count: -6