panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 951 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 156565 34552 0 0 0 1 syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff834692d8) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff834165c5,ffffffff83417362,3b7,ffffffff834173e5) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002f3daf10,ffffffff833613ca) at refcnt_finalize+0x1db sys/kern/kern_synch.c:952 pppx_if_destroy(0,ffff80002f3daf08) at pppx_if_destroy+0x3d sys/net/if_pppx.c:806 pppxclose(205b9a,1,2000,ffff80002f3dd740) at pppxclose+0xa0 sys/net/if_pppx.c:553 spec_close(ffff80003c427530) at spec_close+0x412 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd805db4a990,1,fffffd80097fb2d8,ffff80002f3dd740) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806024b228,ffff80002f3dd740) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806024b228,ffff80002f3dd740) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806024b228,ffff80002f3dd740) at fdrop+0x126 sys/kern/kern_descrip.c:1267 closef(fffffd806024b228,ffff80002f3dd740) at closef+0x192 sys/kern/kern_descrip.c:1251 fdfree(ffff80002f3dd740) at fdfree+0x116 sys/kern/kern_descrip.c:1182 exit1(ffff80002f3dd740,0,0,1) at exit1+0x59c sys/kern/kern_exit.c:215 sys_exit(ffff80002f3dd740,ffff80003c4278a0,ffff80003c4277f0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80003c427890, 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 951 ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff834692d8) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff834165c5,ffffffff83417362,3b7,ffffffff834173e5) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002f3daf10,ffffffff833613ca) at refcnt_finalize+0x1db sys/kern/kern_synch.c:952 pppx_if_destroy(0,ffff80002f3daf08) at pppx_if_destroy+0x3d sys/net/if_pppx.c:806 pppxclose(205b9a,1,2000,ffff80002f3dd740) at pppxclose+0xa0 sys/net/if_pppx.c:553 spec_close(ffff80003c427530) at spec_close+0x412 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd805db4a990,1,fffffd80097fb2d8,ffff80002f3dd740) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806024b228,ffff80002f3dd740) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806024b228,ffff80002f3dd740) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806024b228,ffff80002f3dd740) at fdrop+0x126 sys/kern/kern_descrip.c:1267 closef(fffffd806024b228,ffff80002f3dd740) at closef+0x192 sys/kern/kern_descrip.c:1251 fdfree(ffff80002f3dd740) at fdfree+0x116 sys/kern/kern_descrip.c:1182 exit1(ffff80002f3dd740,0,0,1) at exit1+0x59c sys/kern/kern_exit.c:215 sys_exit(ffff80002f3dd740,ffff80003c4278a0,ffff80003c4277f0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003c4278a0) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c4278a0) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:742 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7170c62e26c0, count: -16 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80003c427300 rbx 0xffffffff8383edd7 cpu_info_full_primary+0x2dd7 rdx 0 rcx 0xffff80002f3dd740 rax 0xffffffff8383dff0 cpu_info_full_primary+0x1ff0 r8 0 r9 0x8080808080808080 r10 0xde15b4e262b574b3 r11 0x19ca79d2af308541 r12 0xffffffff8383ebd8 cpu_info_full_primary+0x2bd8 r13 0 r14 0 r15 0x1 rip 0xffffffff821458c5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003c4272f0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=520574 pid=59636 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=32, usrpri=86, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff80002f3dd740 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff80002a2979c0,0xffff80002a2974b0 process=0xffff800032fee6e0 user=0xffff80003c422000, vmspace=0xfffffd806c2045b8 estcpu=36, cpticks=8, pctcpu=0.0, user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 34552 156565 73216 0 7 0 syz-executor 53970 95260 65075 0 2 0 syz-executor 68934 523546 67105 0 2 0 syz-executor 68934 358354 67105 0 3 0x4000080 fsleep syz-executor 61331 214450 70620 0 2 0 syz-executor 61331 132952 70620 0 2 0x4000000 syz-executor 60053 292764 88099 0 2 0 syz-executor 60053 225230 88099 0 3 0x4000080 fifor syz-executor 35923 465729 76448 0 3 0x80 nanoslp syz-executor 35923 102794 76448 0 3 0x4000080 msgwait syz-executor 35923 348742 76448 0 3 0x4000080 msgwait syz-executor 35923 163318 76448 0 3 0x4000080 fsleep syz-executor 93259 23073 65743 0 2 0x2 syz-executor 96448 174999 0 0 3 0x14200 bored sosplice 74512 252468 96385 0 3 0x100082 sbwait ndp 96385 227229 18790 0 3 0x10008a sigsusp sh 70620 10576 65743 0 2 0xc82 syz-executor 67105 200900 65743 0 3 0x82 nanoslp syz-executor 88099 153938 65743 0 2 0xc82 syz-executor 73216 48968 65743 0 3 0x82 nanoslp syz-executor 65075 416674 65743 0 2 0x2 syz-executor 18790 141353 65743 0 3 0x82 wait syz-executor 76448 474463 65743 0 3 0x82 nanoslp syz-executor 65743 227968 31632 0 3 0x82 kqread syz-executor 31632 170949 15070 0 3 0x10008a sigsusp ksh 15070 34414 21068 0 3 0x98 kqread sshd-session 21068 290165 94170 0 3 0x92 kqread sshd-session 62783 95940 1 0 3 0x100083 ttyin getty 94170 246471 1 0 3 0x88 kqread sshd 64423 495937 26667 74 3 0x1100092 bpf pflogd 26667 329666 1 0 3 0x80 sbwait pflogd 44871 86877 29468 73 3 0x1100090 kqread syslogd 29468 150246 1 0 3 0x100082 sbwait syslogd 10199 291951 1 0 3 0x100080 kqread resolvd 75110 71070 40352 77 3 0x100092 kqread dhcpleased 87463 312000 40352 77 2 0x100012 dhcpleased 40352 441555 1 0 3 0x80 kqread dhcpleased 66168 106352 0 0 3 0x14200 pause smr 23757 97853 0 0 2 0x14200 zerothread 88614 325096 0 0 3 0x14200 aiodoned aiodoned 88825 148300 0 0 3 0x14200 syncer update 21391 98370 0 0 3 0x14200 cleaner cleaner 59777 362977 0 0 3 0x14200 reaper reaper 84605 201883 0 0 3 0x14200 pgdaemon pagedaemon 23272 341210 0 0 3 0x14200 bored viomb 72568 5101 0 0 3 0x40014200 acpi0 acpi0 66094 511642 0 0 3 0x40014200 idle1 11896 255992 0 0 3 0x14200 bored softnet3 30634 94709 0 0 3 0x14200 bored softnet2 92453 387035 0 0 3 0x14200 bored softnet1 72012 45760 0 0 2 0x14200 softnet0 65883 378418 0 0 3 0x14200 bored systqmp 44102 497211 0 0 3 0x14200 bored systq 6674 195121 0 0 3 0x14200 tmoslp softclockmp 13011 293642 0 0 3 0x40014200 tmoslp softclock 2877 351871 0 0 3 0x40014200 idle0 1 277728 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{0}> show all locks Process 34552 (syz-executor) thread 0xffff80002f3dcf90 (156565) exclusive rwlock uobjlk r = 0 (0xfffffd8077349a08) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x377 sys/kern/kern_rwlock.c:310 #2 uvm_fault_lower_lookup+0x53 sys/uvm/uvm_fault.c:1236 #3 uvm_fault_lower+0x89 sys/uvm/uvm_fault.c:1370 #4 uvm_fault+0x278 sys/uvm/uvm_fault.c:-1 #5 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192 #6 usertrap+0x3e3 sys/arch/amd64/amd64/trap.c:599 #7 recall_trap+0x8 shared rwlock vmmaplk r = 0 (0xfffffd806c2042f8) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1160 #1 rw_do_enter_read+0x36e sys/kern/kern_rwlock.c:397 #2 uvmfault_lookup+0x122 sys/uvm/uvm_fault.c:1924 #3 uvm_fault_check+0x4a sys/uvm/uvm_fault.c:741 #4 uvm_fault+0x106 sys/uvm/uvm_fault.c:677 #5 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192 #6 usertrap+0x3e3 sys/arch/amd64/amd64/trap.c:599 #7 recall_trap+0x8 Process 72012 (softnet0) thread 0xffff8000ffffea40 (45760) shared rwlock softnet0 r = 0 (0xffff80000002c078) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1160 #1 taskq_thread+0x12a sys/kern/kern_task.c:442 #2 proc_trampoline+0x10 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10226 11035K 11551K 166960K 12288 0 pcb 18 12K 12K 166960K 111 0 rtable 223 10K 10K 166960K 482 0 pf 40 18K 82K 166960K 95 0 ifaddr 45 8K 8K 166960K 83 0 ifgroup 61 2K 2K 166960K 118 0 sysctl 3 1K 9K 166960K 12 0 counters 74 37K 38K 166960K 274 0 ioctlops 0 0K 4K 166960K 1660 0 iov 0 0K 24K 166960K 35 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1365 86K 87K 166960K 1923 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 8 0 VM map 2 1K 1K 166960K 2 0 sem 15 3K 3K 166960K 20 0 dirhash 12 2K 2K 166960K 18 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 19 69K 110K 166960K 679 0 sigio 0 0K 0K 166960K 8 0 proc 72 91K 128K 166960K 591 0 subproc 72 4K 4K 166960K 81 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 82 0 in_multi 92 6K 7K 166960K 144 0 ether_multi 1 0K 0K 166960K 3 0 mrt 0 0K 0K 166960K 8 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 91 413K 413K 166960K 91 0 exec 0 0K 1K 166960K 490 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 2 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 232 153K 163K 166960K 7829 0 UVM aobj 13 4K 4K 166960K 14 0 pinsyscall 45 90K 104K 166960K 1811 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 21 0 NDP 14 0K 2K 166960K 50 0 temp 44 8687K 8753K 166960K 23200 0 kqueue 14 22K 26K 166960K 136 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 120 132 0 128 3 2 1 3 0 8 0 rtentry 176 142 0 48 6 0 6 6 0 8 0 unpcb 144 418 0 399 6 0 6 6 0 8 4 syncache 336 5 0 5 2 1 1 1 0 8 1 tcpqe 32 3 0 3 1 0 1 1 0 8 1 tcpcb 736 230 0 223 7 0 7 7 0 8 5 arp 128 21 0 4 1 0 1 1 0 8 0 inpcb 328 579 0 566 7 0 7 7 0 8 5 nd6 144 26 0 6 1 0 1 1 0 8 0 pkpcb 40 8 0 8 1 0 1 1 0 8 1 kcovpl 48 9 0 1 1 0 1 1 0 8 0 ppxss 1192 94 0 92 1 0 1 1 0 8 0 pppxif 1504 8 0 7 2 1 1 1 0 8 0 pffrag 232 70 0 65 1 0 1 1 0 482 0 pffrnode 88 69 0 65 1 0 1 1 0 8 0 pffrent 40 137 0 132 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 pftag 88 1 0 0 1 0 1 1 0 8 0 pfstitem 24 51 0 12 1 0 1 1 0 8 0 pfstkey 128 51 0 12 2 0 2 2 0 8 0 pfstate 384 51 0 12 5 0 5 5 0 8 0 pfrule 1344 28 0 20 2 1 1 2 0 8 0 rttmr 136 3 0 3 1 0 1 1 0 8 1 art_heap8 4096 3 0 0 3 0 3 3 0 8 0 art_heap4 256 600 0 192 29 2 27 29 0 8 1 art_table 32 603 0 192 4 0 4 4 0 8 0 art_node 16 140 0 56 1 0 1 1 0 8 0 sysvmsgpl 40 3 0 3 1 0 1 1 0 8 1 semapl 112 15 0 2 1 0 1 1 0 8 0 shmpl 112 11 0 1 1 0 1 1 0 8 0 dirhash 1024 21 0 4 3 0 3 3 0 8 0 dino2pl 256 2624 0 1122 95 0 95 95 0 8 0 ffsino 288 2624 0 1122 109 0 109 109 0 8 0 nchpl 144 3507 0 1813 64 0 64 64 0 8 0 rtmask 32 7 0 7 2 1 1 1 0 8 1 uvmvnodes 80 3014 0 0 62 0 62 62 0 8 0 vnodes 216 3014 0 0 168 0 168 168 0 8 0 namei 1024 12454 0 12454 2 1 1 2 0 8 1 percpumem 16 152 0 100 1 0 1 1 0 8 0 kstatmem 264 68 0 36 3 0 3 3 0 8 0 scsiplug 72 2 0 2 2 1 1 1 0 8 1 scxspl 216 18171 0 18171 9 7 2 8 1 8 2 plimitpl 152 101 0 84 1 0 1 1 0 8 0 sigapl 424 980 0 928 8 1 7 7 0 8 0 knotepl 120 552 0 0 17 0 17 17 0 8 0 kqueuepl 224 252 0 241 3 0 3 3 0 8 2 pipepl 336 147 0 120 3 0 3 3 0 8 0 fdescpl 520 960 0 927 3 0 3 3 0 8 0 filepl 160 5394 0 5177 17 0 17 17 0 8 7 lockfpl 104 422 0 420 1 0 1 1 0 8 0 lockfspl 48 166 0 164 1 0 1 1 0 8 0 sessionpl 144 24 0 15 1 0 1 1 0 8 0 pgrppl 48 44 0 27 1 0 1 1 0 8 0 ucredpl 104 780 0 766 1 0 1 1 0 8 0 zombiepl 144 929 0 928 1 0 1 1 0 8 0 processpl 1240 980 0 928 5 0 5 5 0 8 0 procpl 656 1926 0 1868 7 0 7 7 0 8 0 srpgc 96 10 0 10 2 1 1 1 0 8 1 sosppl 168 4 0 4 2 1 1 1 0 8 1 sockpl 728 1152 0 1116 15 3 12 15 0 8 8 mcl64k 65536 3 0 0 1 0 1 1 0 8 0 mcl12k 12288 12 0 0 2 0 2 2 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 134 0 0 17 0 17 17 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 51 0 0 7 0 7 7 0 8 0 mtagpl 96 21 0 0 1 0 1 1 0 8 0 mbufpl 256 298 0 0 19 0 19 19 0 8 0 bufpl 280 6933 0 791 439 0 439 439 0 8 0 anonpl 32 10325 0 0 84 0 84 84 0 246 0 amapchunkpl 152 25620 0 25160 30 3 27 28 0 158 6 amappl16 200 3447 0 3422 28 13 15 23 0 8 10 amappl15 192 3 0 3 1 1 0 1 0 8 0 amappl14 184 120 0 107 1 0 1 1 0 8 0 amappl13 176 36 0 36 1 1 0 1 0 8 0 amappl12 168 1632 0 1600 4 1 3 3 0 8 0 amappl11 160 48 0 34 1 0 1 1 0 8 0 amappl10 152 4 0 4 1 1 0 1 0 8 0 amappl9 144 282 0 282 1 1 0 1 0 8 0 amappl8 136 19 0 17 1 0 1 1 0 8 0 amappl7 128 139 0 126 1 0 1 1 0 8 0 amappl6 120 187 0 183 1 0 1 1 0 8 0 amappl5 112 125 0 115 1 0 1 1 0 8 0 amappl4 104 323 0 300 1 0 1 1 0 8 0 amappl3 96 4893 0 4787 5 1 4 4 0 8 0 amappl2 88 670 0 600 2 0 2 2 0 8 0 amappl1 80 10691 0 10062 15 0 15 15 0 8 0 amappl 88 7039 0 6883 5 0 5 5 0 92 1 dma16384 16384 1 0 1 1 0 1 1 0 8 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 7 0 7 2 1 1 1 0 8 1 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 1 1 0 1 1 0 8 0 uaddrrnd 24 960 0 927 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 960 0 927 1 0 1 1 0 8 0 vmmpekpl 168 9378 0 9336 3 0 3 3 0 8 0 vmmpepl 168 66536 0 64484 107 4 103 107 0 357 7 vmsppl 480 959 0 927 5 0 5 5 0 8 0 rwobjpl 72 22960 0 18968 77 0 77 77 0 8 2 pdppl 4096 1927 0 1854 105 32 73 83 0 8 0 pvpl 32 19406 0 0 158 1 157 157 0 265 0 pmappl 256 959 0 927 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 411 0 38 11 0 11 11 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(ffffffff834692d8) at panic+0x1e5 sys/kern/subr_prf.c:198 __assert(ffffffff834165c5,ffffffff83417362,3b7,ffffffff834173e5) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff80002f3daf10,ffffffff833613ca) at refcnt_finalize+0x1db sys/kern/kern_synch.c:952 pppx_if_destroy(0,ffff80002f3daf08) at pppx_if_destroy+0x3d sys/net/if_pppx.c:806 pppxclose(205b9a,1,2000,ffff80002f3dd740) at pppxclose+0xa0 sys/net/if_pppx.c:553 spec_close(ffff80003c427530) at spec_close+0x412 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd805db4a990,1,fffffd80097fb2d8,ffff80002f3dd740) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806024b228,ffff80002f3dd740) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806024b228,ffff80002f3dd740) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806024b228,ffff80002f3dd740) at fdrop+0x126 sys/kern/kern_descrip.c:1267 closef(fffffd806024b228,ffff80002f3dd740) at closef+0x192 sys/kern/kern_descrip.c:1251 fdfree(ffff80002f3dd740) at fdfree+0x116 sys/kern/kern_descrip.c:1182 exit1(ffff80002f3dd740,0,0,1) at exit1+0x59c sys/kern/kern_exit.c:215 sys_exit(ffff80002f3dd740,ffff80003c4278a0,ffff80003c4277f0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003c4278a0) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c4278a0) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:742 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7170c62e26c0, count: -16 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffff8000299ddff0) 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(ffffffff83a1d308) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83a1d308) at __mp_lock+0x199 sys/kern/kern_lock.c:165 syscall(ffff80003c43f590) at syscall+0xae6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c43f590) at syscall+0xae6 sys/arch/amd64/amd64/trap.c:742 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7ed3902a7fc0, count: 9 ddb{1}> trace x86_ipi_db(ffff8000299ddff0) 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(ffffffff83a1d308) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83a1d308) at __mp_lock+0x199 sys/kern/kern_lock.c:165 syscall(ffff80003c43f590) at syscall+0xae6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c43f590) at syscall+0xae6 sys/arch/amd64/amd64/trap.c:742 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7ed3902a7fc0, count: -6