witness: lock order reversal: 1st 0xffff800010fd9158 sbufrcv (&so->so_rcv.sb_lock) 2nd 0xfffffd8071af00c8 inode (&ip->i_lock) lock order [1] sbufrcv (&so->so_rcv.sb_lock) -> [2] inode (&ip->i_lock) lock order data 0xffffffff8343fb6e -> 0xffffffff833a68ec is missing lock order [2] inode (&ip->i_lock) -> [1] sbufrcv (&so->so_rcv.sb_lock) #0 rw_do_enter_write+0xb7 sys/kern/kern_rwlock.c:233 #1 sblock+0xb7 sys/kern/uipc_socket2.c:536 #2 soreceive+0x28e sys/kern/uipc_socket.c:882 #3 fifo_read+0x11a sys/miscfs/fifofs/fifo_vnops.c:264 #4 VOP_READ+0x102 sys/kern/vfs_vops.c:227 #5 vn_rdwr+0x15b #6 vndsetcred+0xa1 sys/dev/vnd.c:684 #7 vndioctl+0xe6c sys/dev/vnd.c:485 #8 VOP_IOCTL+0xac sys/kern/vfs_vops.c:264 #9 vn_ioctl+0xf8 sys/kern/vfs_vnops.c:531 #10 sys_ioctl+0x5c3 #11 syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] #11 syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 #12 Xsyscall+0x128 Stopped at db_enter+0x25: addq $0x8,%rsp ddb{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic the kernel did not panic ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 witness_checkorder(fffffd8071af00c8,9,0) at witness_checkorder+0x1047 rw_do_enter_write(fffffd8071af00b0,1) at rw_do_enter_write+0xb7 sys/kern/kern_rwlock.c:233 rrw_enter(fffffd8071af00b0,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:616 VOP_LOCK(fffffd8069e22440,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd8069e22440,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vfs_getcwd_common(fffffd8069e22440,fffffd8069e22950,0,0,200,0,86964328a24f9918) at vfs_getcwd_common+0xd1 sys/kern/vfs_getcwd.c:287 vn_isunder(fffffd8069e22440,fffffd8069e22950,ffff800033cbfc58) at vn_isunder+0x56 sys/kern/vfs_vnops.c:694 unp_externalize(fffffd806a95fc00,33,0) at unp_externalize+0x286 sys/kern/uipc_usrreq.c:1086 soreceive(ffff800010fd9078,ffff800033cbd6a8,ffff800033cbd658,0,ffff800033cbd698,ffff800033cbd81c,652c35da79cee82b) at soreceive+0xc73 sys/kern/uipc_socket.c:1021 recvit(ffff800033cbfc58,9,ffff800033cbd7f0,0,ffff800033cbd8a0) at recvit+0x40a sys/kern/uipc_syscalls.c:1072 sys_recvmsg(ffff800033cbfc58,ffff800033cbd950,ffff800033cbd8a0) at sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:872 syscall(ffff800033cbd950) at syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800033cbd950) at syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x101f0960f00, count: -14 ddb{0}> show registers rdi 0 rsi 0x80000 acpi_pdirpa+0x6be71 rbp 0xffff800033cbd130 rbx 0xfffffd8004709680 rdx 0xffff80000144d240 rcx 0xffff800033cbfc58 rax 0x7ffff acpi_pdirpa+0x6be70 r8 0xffff800033cbd010 r9 0x8080808080808080 r10 0x9331fa87c51c9635 r11 0x5cef67214c70e4dc r12 0 r13 0xfffffd8003f20f00 r14 0x3 r15 0xffffffff rip 0xffffffff8136a795 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff800033cbd120 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=218996 pid=73893 tcnt=2 stat=onproc flags process=1000000 proc=4000000 runpri=50, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff800033cb6a60,0xffff800033cbed08 process=0xffff8000ffff8de0 user=0xffff800033cb8000, vmspace=0xfffffd806beb0018 estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 87065 230633 81514 0 2 0 syz-executor 73893 71611 8005 0 7 0x1000000 syz-executor *73893 218996 8005 0 7 0x5000000 syz-executor 73609 96789 65905 60929 2 0x10 syz-executor 73609 401848 65905 60929 3 0x4000090 fsleep syz-executor 28567 305195 52140 0 2 0 syz-executor 28567 270195 52140 0 3 0x4000080 fsleep syz-executor 26503 330966 98853 0 2 0 syz-executor 26503 136997 98853 0 3 0x4000080 fsleep syz-executor 43354 296658 99568 0 2 0 syz-executor 43354 500689 99568 0 3 0x4000000 smrbar syz-executor 56034 270497 71131 0 2 0 syz-executor 56034 223895 71131 0 3 0x4000080 fsleep syz-executor 50210 266522 66959 0 2 0 syz-executor 50210 384869 66959 0 3 0x4000080 fsleep syz-executor 50210 436597 66959 0 3 0x4000080 fsleep syz-executor 81514 251091 35655 0 3 0x82 nanoslp syz-executor 24498 208150 1 0 3 0x100083 ttyin getty 98853 503100 35655 0 3 0x82 nanoslp syz-executor 67807 432032 0 0 3 0x14280 nfsidl nfsio 75990 419085 0 0 3 0x14280 nfsidl nfsio 42570 433668 0 0 3 0x14280 nfsidl nfsio 30999 380091 0 0 3 0x14280 nfsidl nfsio 34510 137370 0 0 3 0x14280 nfsidl nfsio 32083 176833 0 0 3 0x14280 nfsidl nfsio 93791 321459 0 0 3 0x14280 nfsidl nfsio 24253 499705 0 0 3 0x14280 nfsidl nfsio 87353 523726 0 0 3 0x14280 nfsidl nfsio 53886 65342 0 0 3 0x14280 nfsidl nfsio 38158 4421 0 0 3 0x14280 nfsidl nfsio 49945 477093 0 0 3 0x14280 nfsidl nfsio 20879 499938 0 0 3 0x14280 nfsidl nfsio 43264 440149 0 0 3 0x14280 nfsidl nfsio 27883 44483 0 0 3 0x14280 nfsidl nfsio 46649 273499 0 0 3 0x14280 nfsidl nfsio 29050 320064 0 0 3 0x14280 nfsidl nfsio 11691 176330 0 0 3 0x14280 nfsidl nfsio 53046 323521 0 0 3 0x14280 nfsidl nfsio 14780 278622 0 0 3 0x14280 nfsidl nfsio 78067 435473 0 0 3 0x14200 bored sosplice 99568 393728 35655 0 3 0x82 nanoslp syz-executor 71131 150388 35655 0 3 0x82 nanoslp syz-executor 66959 70803 35655 0 3 0x82 nanoslp syz-executor 8005 418467 35655 0 3 0x82 nanoslp syz-executor 65905 453626 35655 0 3 0x82 nanoslp syz-executor 52140 255707 35655 0 3 0x82 nanoslp syz-executor 35655 93823 72316 0 3 0x82 kqread syz-executor 72316 148010 6496 0 3 0x10008a sigsusp ksh 6496 251068 28879 0 3 0x98 kqread sshd-session 28879 3530 84850 0 3 0x92 kqread sshd-session 84850 419057 1 0 3 0x88 kqread sshd 54377 115686 84503 74 3 0x1100092 bpf pflogd 84503 330806 1 0 3 0x80 sbwait pflogd 94936 27623 32653 73 3 0x1100090 kqread syslogd 32653 391470 1 0 3 0x100082 sbwait syslogd 96028 77442 1 0 3 0x100080 kqread resolvd 88795 228869 61025 77 3 0x100092 kqread dhcpleased 4823 245710 61025 77 3 0x100092 kqread dhcpleased 61025 333059 1 0 3 0x80 kqread dhcpleased 88007 308345 0 0 3 0x14200 bored smr 79511 168554 0 0 2 0x14200 zerothread 73675 232415 0 0 3 0x14200 aiodoned aiodoned 85531 342610 0 0 3 0x14200 syncer update 93444 165986 0 0 3 0x14200 cleaner cleaner 87844 115788 0 0 3 0x14200 reaper reaper 10667 224304 0 0 3 0x14200 pgdaemon pagedaemon 84157 73134 0 0 3 0x14200 bored viomb 98721 290830 0 0 3 0x40014200 acpi0 acpi0 32057 322470 0 0 3 0x40014200 idle1 21449 113533 0 0 3 0x14200 bored softnet3 81889 344760 0 0 3 0x14200 bored softnet2 22170 312138 0 0 3 0x14200 bored softnet1 12658 75519 0 0 3 0x14200 bored softnet0 49510 371619 0 0 3 0x14200 bored systqmp 96663 291078 0 0 3 0x14200 bored systq 56492 154255 0 0 3 0x14200 tmoslp softclockmp 1304 228404 0 0 3 0x40014200 tmoslp softclock 15897 243341 0 0 3 0x40014200 idle0 1 438390 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{0}> show all locks Process 73893 (syz-executor) thread 0xffff800033cbfc58 (218996) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8398f708) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1155 #1 unp_externalize+0x14e #2 soreceive+0xc73 sys/kern/uipc_socket.c:1021 #3 recvit+0x40a sys/kern/uipc_syscalls.c:1072 #4 sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:872 #5 syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] #5 syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 #6 Xsyscall+0x128 exclusive rwlock sbufrcv r = 0 (0xffff800010fd9158) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1155 #1 rw_do_enter_write+0x3ea sys/kern/kern_rwlock.c:316 #2 sblock+0xb7 sys/kern/uipc_socket2.c:536 #3 soreceive+0x28e sys/kern/uipc_socket.c:882 #4 recvit+0x40a sys/kern/uipc_syscalls.c:1072 #5 sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:872 #6 syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] #6 syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 #7 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10233 11038K 11550K 166960K 14434 0 pcb 17 16K 18K 166960K 429 0 rtable 221 9K 10K 166960K 658 0 pf 34 17K 25K 166960K 146 0 ifaddr 39 6K 8K 166960K 107 0 ifgroup 53 2K 2K 166960K 187 0 sysctl 3 1K 1K 166960K 3 0 counters 64 36K 37K 166960K 192 0 ioctlops 0 0K 4K 166960K 1669 0 iov 0 0K 28K 166960K 155 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1395 88K 88K 166960K 2775 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 3 14K 14K 166960K 35 0 VM map 2 1K 1K 166960K 2 0 sem 15 16K 16K 166960K 326 0 dirhash 12 2K 2K 166960K 42 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 97K 166960K 1882 0 sigio 0 0K 0K 166960K 28 0 proc 73 91K 128K 166960K 814 0 subproc 72 4K 4K 166960K 92 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 1 0K 0K 166960K 595 0 in_multi 84 6K 7K 166960K 163 0 ether_multi 2 0K 0K 166960K 6 0 mrt 1 0K 0K 166960K 6 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 259 1155K 1155K 166960K 259 0 exec 0 0K 1K 166960K 708 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 8 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 221 72K 90K 166960K 19180 0 UVM aobj 6 2K 4K 166960K 7 0 pinsyscall 43 86K 108K 166960K 3068 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 101 0 NDP 12 0K 2K 166960K 76 0 temp 78 8644K 8712K 166960K 71482 0 kqueue 15 20K 32K 166960K 305 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 24 0 0 1 0 1 1 0 8 0 rtpcb 120 205 0 202 3 2 1 3 0 8 0 rtentry 112 174 0 79 4 0 4 4 0 8 0 unpcb 144 1253 0 1232 11 9 2 6 0 8 1 syncache 336 14 0 14 4 4 0 1 0 8 0 tcpqe 32 10 0 10 3 3 0 1 0 8 0 tcpcb 808 770 0 760 13 12 1 8 0 8 0 arp 120 29 0 14 1 0 1 1 0 8 0 ipq 40 2 0 2 1 1 0 1 0 8 0 ipqe 40 4 0 4 1 1 0 1 0 8 0 inpcb 376 2462 0 2447 13 6 7 9 0 8 4 ip6q 72 1 0 1 1 1 0 1 0 8 0 ip6af 40 2 0 2 1 1 0 1 0 8 0 nd6 136 34 0 14 1 0 1 1 0 8 0 pkpcb 40 29 0 29 2 2 0 1 0 8 0 kcovpl 48 10 0 2 1 0 1 1 0 8 0 ppxss 1168 46 0 45 3 2 1 1 0 8 0 pppxif 1472 8 0 8 3 3 0 1 0 8 0 pffrag 232 12 0 6 1 0 1 1 0 482 0 pffrnode 88 11 0 5 1 0 1 1 0 8 0 pffrent 40 21 0 15 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 24 113 0 54 1 0 1 1 0 8 0 pfstkey 128 113 0 54 3 0 3 3 0 8 0 pfstate 376 113 0 54 8 0 8 8 0 8 0 pfrule 1344 22 0 16 2 1 1 2 0 8 0 art_heap8 4096 4 0 0 4 0 4 4 0 8 0 art_heap4 256 656 0 261 31 3 28 29 0 8 0 art_table 32 660 0 261 4 0 4 4 0 8 0 art_node 16 170 0 84 1 0 1 1 0 8 0 sysvmsgpl 40 14 0 11 1 0 1 1 0 8 0 semupl 112 1 0 1 1 0 1 1 0 8 1 semapl 112 322 0 309 1 0 1 1 0 8 0 shmpl 112 4 0 1 1 0 1 1 0 8 0 dirhash 1024 37 0 20 3 0 3 3 0 8 0 dino2pl 256 4725 0 3213 95 0 95 95 0 8 0 ffsino 280 4725 0 3213 109 0 109 109 0 8 0 nchpl 144 7393 0 5696 64 0 64 64 0 8 0 rtmask 32 8 0 8 4 4 0 1 0 8 0 uvmvnodes 80 5652 0 0 116 0 116 116 0 8 0 vnodes 216 5652 0 0 314 0 314 314 0 8 0 namei 1024 25525 0 25525 2 1 1 1 0 8 1 percpumem 16 110 0 64 1 0 1 1 0 8 0 kstatmem 264 104 0 80 3 1 2 3 0 8 0 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 8 0 8 3 3 0 1 0 8 0 scxspl 216 24294 0 24294 11 10 1 5 1 8 1 plimitpl 152 435 0 418 1 0 1 1 0 8 0 sigapl 424 2210 0 2139 10 1 9 9 0 8 0 futexpl 64 26960 0 26954 1 0 1 1 0 8 0 knotepl 120 787 0 0 24 0 24 24 0 8 0 kqueuepl 216 576 0 565 6 5 1 5 0 8 0 pipepl 328 284 0 255 5 2 3 5 0 8 0 fdescpl 504 2170 0 2138 6 1 5 6 0 8 0 filepl 152 14567 0 14339 25 14 11 18 0 8 1 lockfpl 104 826 0 824 3 2 1 2 0 8 0 lockfspl 48 236 0 234 1 0 1 1 0 8 0 sessionpl 144 35 0 26 1 0 1 1 0 8 0 pgrppl 48 72 0 55 1 0 1 1 0 8 0 ucredpl 104 2297 0 2283 1 0 1 1 0 8 0 zombiepl 144 2139 0 2139 1 0 1 1 0 8 1 processpl 1176 2210 0 2139 7 1 6 6 0 8 0 procpl 656 5159 0 5080 8 0 8 8 0 8 0 srpgc 96 4 0 4 2 2 0 1 0 8 0 sosppl 168 13 0 13 4 3 1 1 0 8 1 sockpl 688 4046 0 4007 29 18 11 16 0 8 5 mcl64k 65536 5 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 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 128 0 0 16 0 16 16 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 30 0 0 4 0 4 4 0 8 0 mtagpl 96 224 0 0 6 0 6 6 0 8 0 mbufpl 256 579 0 0 37 0 37 37 0 8 0 bufpl 280 8631 0 2476 440 0 440 440 0 8 0 anonpl 24 271268 0 267548 69 29 40 53 0 184 5 amapchunkpl 152 62853 0 62376 39 15 24 35 0 158 3 amappl16 200 5133 0 5085 35 31 4 15 0 8 0 amappl15 192 57 0 57 3 3 0 1 0 8 0 amappl14 184 150 0 138 1 0 1 1 0 8 0 amappl13 176 7 0 6 3 2 1 1 0 8 0 amappl12 168 2851 0 2820 4 1 3 3 0 8 0 amappl11 160 54 0 40 1 0 1 1 0 8 0 amappl10 152 7 0 6 1 0 1 1 0 8 0 amappl9 144 253 0 252 1 0 1 1 0 8 0 amappl8 136 22 0 19 1 0 1 1 0 8 0 amappl7 128 124 0 111 1 0 1 1 0 8 0 amappl6 120 205 0 202 1 0 1 1 0 8 0 amappl5 112 132 0 122 1 0 1 1 0 8 0 amappl4 104 369 0 346 1 0 1 1 0 8 0 amappl3 96 12995 0 12883 4 0 4 4 0 8 0 amappl2 88 765 0 700 2 0 2 2 0 8 0 amappl1 80 15462 0 14886 15 0 15 15 0 8 0 amappl 88 18636 0 18471 5 0 5 5 0 92 0 dma16384 16384 1 0 1 1 1 0 1 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 7 0 7 2 2 0 1 0 8 0 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 7 0 7 2 2 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 19 0 18 1 0 1 1 0 8 0 aobjpl 72 6 0 1 1 0 1 1 0 8 0 uaddrrnd 24 2170 0 2138 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2170 0 2138 1 0 1 1 0 8 0 vmmpekpl 168 18456 0 18401 3 0 3 3 0 8 0 vmmpepl 168 136434 0 134501 106 15 91 98 0 357 2 vmsppl 456 2169 0 2138 6 1 5 5 0 8 0 rwobjpl 64 41512 0 34900 107 0 107 107 0 8 0 pdppl 4096 4348 0 4276 114 42 72 88 0 8 0 pvpl 32 16101 0 0 131 1 130 130 0 265 0 pmappl 248 2169 0 2138 3 0 3 3 0 8 0 extentpl 40 55 0 38 1 0 1 1 0 8 0 phpool 112 340 0 69 9 1 8 9 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 witness_checkorder(fffffd8071af00c8,9,0) at witness_checkorder+0x1047 rw_do_enter_write(fffffd8071af00b0,1) at rw_do_enter_write+0xb7 sys/kern/kern_rwlock.c:233 rrw_enter(fffffd8071af00b0,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:616 VOP_LOCK(fffffd8069e22440,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd8069e22440,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vfs_getcwd_common(fffffd8069e22440,fffffd8069e22950,0,0,200,0,86964328a24f9918) at vfs_getcwd_common+0xd1 sys/kern/vfs_getcwd.c:287 vn_isunder(fffffd8069e22440,fffffd8069e22950,ffff800033cbfc58) at vn_isunder+0x56 sys/kern/vfs_vnops.c:694 unp_externalize(fffffd806a95fc00,33,0) at unp_externalize+0x286 sys/kern/uipc_usrreq.c:1086 soreceive(ffff800010fd9078,ffff800033cbd6a8,ffff800033cbd658,0,ffff800033cbd698,ffff800033cbd81c,652c35da79cee82b) at soreceive+0xc73 sys/kern/uipc_socket.c:1021 recvit(ffff800033cbfc58,9,ffff800033cbd7f0,0,ffff800033cbd8a0) at recvit+0x40a sys/kern/uipc_syscalls.c:1072 sys_recvmsg(ffff800033cbfc58,ffff800033cbd950,ffff800033cbd8a0) at sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:872 syscall(ffff800033cbd950) at syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800033cbd950) at syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x101f0960f00, count: -14 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp ddb{1}> trace x86_ipi_db(ffff800029aabff0) 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(ffffffff8398f500) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff8398f500) at __mp_lock+0x199 sys/kern/kern_lock.c:144 syscall(ffff800031cb4b40) at syscall+0xae6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800031cb4b40) at syscall+0xae6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7d525efe4810, count: -6