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 db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833952a6) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833d6cb0,ffffffff833e1459,3b9,ffffffff8340b082) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c51a930,ffffffff8338f819) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(285b98,ffff80003c51a928) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(285b98,1,2000,ffff8000ffffd760) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80002a39de10) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd80782b8450,1,fffffd80097fb5b0,ffff8000ffffd760) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd805de0c1e0,ffff8000ffffd760) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd805de0c1e0,ffff8000ffffd760) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd805de0c1e0,ffff8000ffffd760) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd805de0c1e0,ffff8000ffffd760) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff8000ffffd760) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff8000ffffd760,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000ffffd760,ffff80002a39e180,ffff80002a39e0d0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80002a39e170, 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(ffffffff833952a6) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833d6cb0,ffffffff833e1459,3b9,ffffffff8340b082) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c51a930,ffffffff8338f819) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(285b98,ffff80003c51a928) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(285b98,1,2000,ffff8000ffffd760) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80002a39de10) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd80782b8450,1,fffffd80097fb5b0,ffff8000ffffd760) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd805de0c1e0,ffff8000ffffd760) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd805de0c1e0,ffff8000ffffd760) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd805de0c1e0,ffff8000ffffd760) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd805de0c1e0,ffff8000ffffd760) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff8000ffffd760) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff8000ffffd760,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000ffffd760,ffff80002a39e180,ffff80002a39e0d0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80002a39e180) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a39e180) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x761e4706a700, count: -16 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80002a39dbe0 rbx 0xffffffff83827ddf cpu_info_full_primary+0x2ddf rdx 0 rcx 0xffff8000ffffd760 rax 0xffffffff83826ff0 cpu_info_full_primary+0x1ff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xa5bb130e6c79852d r11 0x9117cf5b9441dd84 r12 0xffffffff83827be0 cpu_info_full_primary+0x2be0 r13 0 r14 0 r15 0x1 rip 0xffffffff814258f5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a39dbd0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=347997 pid=42099 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=32, usrpri=86, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff8000ffffd760 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff8000ffff22b0,0xffff80003c4f3270 process=0xffff80003c4226a0 user=0xffff80002a399000, vmspace=0xfffffd806c1c8d70 estcpu=36, cpticks=7, pctcpu=0.0, user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 19579 275766 16271 0 2 0 syz-executor 19579 447217 16271 0 3 0x4000080 fsleep syz-executor 19579 322435 16271 0 2 0x4000000 syz-executor 19579 151751 16271 0 3 0x4000000 smrbar syz-executor 25427 279054 26990 0 2 0xc80 syz-executor 25427 45150 26990 0 3 0x4000080 sbwait syz-executor 25427 63461 26990 0 3 0x4000080 fsleep syz-executor 35632 243423 69921 0 2 0xc80 syz-executor 35632 501636 69921 0 3 0x4000080 ttyout syz-executor 35632 69239 69921 0 3 0x4000080 fsleep syz-executor 67232 190905 40816 0 2 0xc80 syz-executor 67232 179849 40816 0 3 0x4000080 lockf syz-executor 67232 482777 40816 0 3 0x4000080 lockf syz-executor 67232 124907 40816 0 3 0x4000080 fsleep syz-executor 81430 481161 0 0 3 0x14200 acct acct 72372 139229 88285 0 2 0xc82 syz-executor 95934 250617 88285 0 2 0xc82 syz-executor 26990 406930 88285 0 2 0xc82 syz-executor 51516 469643 88285 0 3 0x82 piperd syz-executor 25822 40314 0 0 3 0x14280 nfsidl nfsio 20053 97974 0 0 3 0x14280 nfsidl nfsio 89676 39968 0 0 3 0x14280 nfsidl nfsio 4457 442777 0 0 3 0x14280 nfsidl nfsio 95852 277284 0 0 3 0x14280 nfsidl nfsio 3844 26816 0 0 3 0x14280 nfsidl nfsio 29953 502688 0 0 3 0x14280 nfsidl nfsio 60735 254515 0 0 3 0x14280 nfsidl nfsio 1881 76642 0 0 3 0x14280 nfsidl nfsio 67256 475787 0 0 3 0x14280 nfsidl nfsio 44721 453398 0 0 3 0x14280 nfsidl nfsio 77698 145803 0 0 3 0x14280 nfsidl nfsio 75528 225335 0 0 3 0x14280 nfsidl nfsio 67872 244451 0 0 3 0x14280 nfsidl nfsio 7923 249427 0 0 3 0x14280 nfsidl nfsio 66597 376589 0 0 3 0x14280 nfsidl nfsio 26139 136844 0 0 3 0x14280 nfsidl nfsio 99485 177357 0 0 3 0x14280 nfsidl nfsio 2816 239430 0 0 3 0x14280 nfsidl nfsio 67246 279387 0 0 3 0x14280 nfsidl nfsio 40816 371666 88285 0 2 0xc82 syz-executor 16271 168689 88285 0 2 0xc82 syz-executor 69921 183361 88285 0 2 0xc82 syz-executor 84558 408755 88285 0 2 0xc82 syz-executor 88285 508360 47351 0 2 0x2 syz-executor 47351 401228 90120 0 3 0x10008a sigsusp ksh 90120 467247 48715 0 3 0x98 kqread sshd-session 48715 346244 39667 0 3 0x92 kqread sshd-session 53217 65917 1 0 3 0x100083 ttyopn getty 39667 197630 1 0 3 0x88 kqread sshd 15788 280021 71807 74 3 0x1100092 bpf pflogd 71807 51100 1 0 3 0x80 sbwait pflogd 36220 489721 6004 73 3 0x1100090 kqread syslogd 6004 313484 1 0 3 0x100082 sbwait syslogd 88849 474628 1 0 2 0x100080 resolvd 95020 355203 11784 77 2 0x100092 dhcpleased 8513 102248 11784 77 3 0x100092 kqread dhcpleased 11784 37483 1 0 3 0x80 kqread dhcpleased 88753 337523 0 0 3 0x14200 bored smr 60561 339685 0 0 2 0x14200 zerothread 74358 406597 0 0 3 0x14200 aiodoned aiodoned 67589 255176 0 0 3 0x14200 syncer update 45881 245698 0 0 3 0x14200 cleaner cleaner 35673 353256 0 0 3 0x14200 reaper reaper 65921 517676 0 0 3 0x14200 pgdaemon pagedaemon 10327 260178 0 0 3 0x14200 bored viomb 89508 190543 0 0 3 0x40014200 acpi0 acpi0 42960 458085 0 0 3 0x40014200 idle1 14094 274689 0 0 3 0x14200 bored softnet1 27652 228722 0 0 2 0x14200 softnet0 53758 109670 0 0 3 0x14200 bored systqmp 19602 44912 0 0 3 0x14200 bored systq 50647 252337 0 0 3 0x14200 tmoslp softclockmp 20632 14931 0 0 3 0x40014200 tmoslp softclock 62390 42502 0 0 3 0x40014200 idle0 1 121859 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{0}> show all locks Process 25427 (syz-executor) thread 0xffff80003c5634e8 (45150) exclusive rwlock sbufrcv r = 0 (0xffff800001635310) #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 sblock+0xb6 sys/kern/uipc_socket2.c:536 #3 soreceive+0x27d sys/kern/uipc_socket.c:878 #4 recvit+0x40b sys/kern/uipc_syscalls.c:1078 #5 sys_recvmmsg+0x410 sys/kern/uipc_syscalls.c:969 #6 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #6 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #7 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10207 11106K 12519K 166960K 12460 0 pcb 17 15K 17K 166960K 306 0 rtable 259 12K 12K 166960K 667 0 pf 40 18K 19K 166960K 115 0 ifaddr 47 8K 8K 166960K 127 0 ifgroup 62 2K 2K 166960K 130 0 sysctl 3 1K 9K 166960K 14 0 counters 74 37K 37K 166960K 160 0 ioctlops 0 0K 4K 166960K 1704 0 iov 1 4K 16K 166960K 120 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1488 93K 94K 166960K 2183 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 37 0 dirhash 12 2K 2K 166960K 15 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 16 57K 89K 166960K 916 0 sigio 0 0K 0K 166960K 21 0 proc 73 115K 164K 166960K 758 0 subproc 72 4K 4K 166960K 117 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 91 0 in_multi 97 7K 7K 166960K 185 0 ether_multi 1 0K 0K 166960K 8 0 mrt 1 0K 0K 166960K 8 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 558 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 252 168K 178K 166960K 10143 0 UVM aobj 22 4K 4K 166960K 24 0 pinsyscall 41 82K 100K 166960K 2175 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 2 0K 1K 166960K 48 0 NDP 14 0K 2K 166960K 65 0 temp 63 8660K 8913K 166960K 32443 0 kqueue 15 24K 28K 166960K 173 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 120 246 0 243 3 2 1 3 0 8 0 rtentry 176 216 0 109 6 1 5 6 0 8 0 unpcb 144 572 0 549 7 3 4 4 0 8 3 syncache 336 5 0 5 1 1 0 1 0 8 0 tcpqe 32 2 0 2 1 1 0 1 0 8 0 tcpcb 736 352 0 344 12 5 7 7 0 8 6 arp 136 29 0 10 1 0 1 1 0 8 0 inpcb 328 1069 0 1056 12 5 7 9 0 8 5 nd6 152 41 0 16 1 0 1 1 0 8 0 pkpcb 40 3 0 3 1 1 0 1 0 8 0 kcovpl 48 13 0 5 1 0 1 1 0 8 0 ppxss 1192 37 0 35 1 0 1 1 0 8 0 pppxif 1504 3 0 2 2 1 1 1 0 8 0 pfstscr 40 2 0 2 1 1 0 1 0 8 0 pffrag 232 8 0 1 1 0 1 1 0 482 0 pffrnode 88 7 0 1 1 0 1 1 0 8 0 pffrent 40 10 0 3 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 1 0 1 1 1 0 1 0 8 0 pftag 88 1 0 0 1 0 1 1 0 8 0 pfstitem 24 55 0 22 1 0 1 1 0 8 0 pfstkey 128 57 0 24 2 0 2 2 0 8 0 pfstate 384 56 0 23 5 0 5 5 0 8 0 pfrule 1344 22 0 17 2 1 1 2 0 8 0 rttmr 136 2 0 2 2 2 0 1 0 8 0 art_heap8 4096 3 0 0 3 0 3 3 0 8 0 art_heap4 256 778 0 340 31 3 28 29 0 8 0 art_table 40 781 0 340 5 0 5 5 0 8 0 art_node 32 213 0 119 1 0 1 1 0 8 0 sysvmsgpl 40 5 0 3 1 0 1 1 0 8 0 semapl 112 33 0 23 1 0 1 1 0 8 0 shmpl 112 21 0 2 1 0 1 1 0 8 0 dirhash 1024 19 0 2 3 0 3 3 0 8 0 dino2pl 256 3035 0 1521 95 0 95 95 0 8 0 ffsino 296 3035 0 1521 117 0 117 117 0 8 0 nchpl 144 4218 0 2501 64 0 64 64 0 8 0 rtmask 32 11 0 11 1 0 1 1 0 8 1 vnodes 216 3583 0 0 200 0 200 200 0 8 0 namei 1024 14639 0 14639 2 1 1 2 0 8 1 percpumem 16 95 0 43 1 0 1 1 0 8 0 kstatmem 264 80 0 50 3 1 2 3 0 8 0 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 2 0 2 2 2 0 1 0 8 0 scxspl 216 21964 0 21964 13 9 4 8 1 8 4 plimitpl 152 318 0 299 1 0 1 1 0 8 0 sigapl 424 1240 0 1172 9 1 8 8 0 8 0 knotepl 120 532 0 0 16 0 16 16 0 8 0 kqueuepl 224 441 0 426 6 4 2 5 0 8 1 pipepl 344 224 0 197 7 3 4 6 0 8 1 fdescpl 528 1199 0 1169 3 0 3 3 0 8 0 filepl 160 7563 0 7328 20 6 14 18 0 8 3 lockfpl 104 522 0 517 3 0 3 3 0 8 2 lockfspl 48 190 0 187 1 0 1 1 0 8 0 sessionpl 144 28 0 19 1 0 1 1 0 8 0 pgrppl 48 48 0 31 1 0 1 1 0 8 0 ucredpl 104 1301 0 1288 1 0 1 1 0 8 0 zombiepl 144 1175 0 1172 1 0 1 1 0 8 0 processpl 1232 1240 0 1172 6 0 6 6 0 8 0 procpl 664 2548 0 2470 8 0 8 8 0 8 0 sosppl 176 6 0 6 2 2 0 1 0 8 0 sockpl 752 1918 0 1879 17 7 10 14 0 8 5 mcl64k 65536 4 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 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 113 0 0 15 0 15 15 0 8 0 mcl2k 2048 33 0 0 5 0 5 5 0 8 0 mtagpl 96 3 0 0 1 0 1 1 0 8 0 mbufpl 256 1547 0 0 97 0 97 97 0 8 0 bufpl 280 8513 0 2376 439 0 439 439 0 8 0 anonpl 32 10041 0 0 82 1 81 81 0 246 0 amapchunkpl 152 33326 0 32779 34 5 29 33 0 158 3 amappl16 200 4580 0 4540 29 9 20 20 0 8 8 amappl15 192 8 0 8 1 1 0 1 0 8 0 amappl14 184 8 0 8 2 1 1 1 0 8 1 amappl13 176 485 0 484 1 0 1 1 0 8 0 amappl12 168 1645 0 1604 3 0 3 3 0 8 0 amappl11 160 4 0 4 1 1 0 1 0 8 0 amappl10 152 53 0 39 1 0 1 1 0 8 0 amappl9 144 246 0 246 1 1 0 1 0 8 0 amappl8 136 26 0 22 1 0 1 1 0 8 0 amappl7 128 97 0 96 1 0 1 1 0 8 0 amappl6 120 342 0 329 1 0 1 1 0 8 0 amappl5 112 83 0 72 1 0 1 1 0 8 0 amappl4 104 448 0 417 1 0 1 1 0 8 0 amappl3 96 5662 0 5571 4 1 3 3 0 8 0 amappl2 88 1296 0 1222 2 0 2 2 0 8 0 amappl1 80 12814 0 12222 14 0 14 14 0 8 0 amappl 88 9195 0 9021 5 0 5 5 0 92 0 uvmvnodes 80 3583 0 0 74 0 74 74 0 8 0 dma32768 32768 1 0 1 1 0 1 1 0 8 1 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 2 0 1 1 0 1 1 0 8 0 dma256 256 8 0 8 3 2 1 1 0 8 1 dma128 128 254 0 254 2 2 0 1 0 8 0 dma64 64 10 0 10 3 3 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 23 0 2 1 0 1 1 0 8 0 uaddrrnd 24 1200 0 1170 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1200 0 1170 1 0 1 1 0 8 0 vmmpekpl 168 11177 0 11127 3 0 3 3 0 8 0 vmmpepl 168 82781 0 80870 108 3 105 105 0 357 4 vmsppl 488 1199 0 1169 5 0 5 5 0 8 0 rwobjpl 80 28405 0 23850 100 1 99 99 0 8 0 pdppl 4096 2407 0 2338 111 40 71 83 0 8 2 pvpl 32 16759 0 0 137 1 136 136 0 265 0 pmappl 256 1199 0 1169 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 387 0 53 10 0 10 10 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(ffffffff833952a6) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff833d6cb0,ffffffff833e1459,3b9,ffffffff8340b082) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80003c51a930,ffffffff8338f819) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954 pppx_if_destroy(285b98,ffff80003c51a928) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(285b98,1,2000,ffff8000ffffd760) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80002a39de10) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd80782b8450,1,fffffd80097fb5b0,ffff8000ffffd760) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd805de0c1e0,ffff8000ffffd760) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd805de0c1e0,ffff8000ffffd760) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd805de0c1e0,ffff8000ffffd760) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd805de0c1e0,ffff8000ffffd760) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff8000ffffd760) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff8000ffffd760,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000ffffd760,ffff80002a39e180,ffff80002a39e0d0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80002a39e180) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a39e180) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x761e4706a700, count: -16 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffff8000299edff0) 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+0x3d sys/dev/kcov.c:159 exit1(ffff8000ffff2018,0,0,1) at exit1+0x701 sys/kern/kern_exit.c:260 sys_exit(ffff8000ffff2018,ffff80003c433e30,ffff80003c433d80) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003c433e30) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c433e30) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7009cf89d580, count: 7 ddb{1}> trace x86_ipi_db(ffff8000299edff0) 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+0x3d sys/dev/kcov.c:159 exit1(ffff8000ffff2018,0,0,1) at exit1+0x701 sys/kern/kern_exit.c:260 sys_exit(ffff8000ffff2018,ffff80003c433e30,ffff80003c433d80) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003c433e30) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c433e30) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7009cf89d580, count: -8