witness: lock order reversal: 1st 0xffff80000128e9e0 sbufsnd (&so->so_snd.sb_lock) 2nd 0xfffffd806f532ba0 inode (&ip->i_lock) lock order [1] sbufsnd (&so->so_snd.sb_lock) -> [2] inode (&ip->i_lock) lock order data 0xffffffff83120c01 -> 0xffffffff830cf67f is missing lock order [2] inode (&ip->i_lock) -> [3] 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:537 #2 soreceive+0x28e sys/kern/uipc_socket.c:876 #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 lock order [3] sbufrcv (&so->so_rcv.sb_lock) -> [1] sbufsnd (&so->so_snd.sb_lock) #0 rw_do_enter_write+0xb7 sys/kern/kern_rwlock.c:233 #1 sblock+0xb7 sys/kern/uipc_socket2.c:537 #2 sosplice+0x40d sys/kern/uipc_socket.c:1358 #3 sys_setsockopt+0x2ba sys/kern/uipc_syscalls.c:1221 #4 syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] #4 syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 #5 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:437 witness_checkorder(fffffd806f532ba0,9,0) at witness_checkorder+0x1047 rw_do_enter_write(fffffd806f532b88,1) at rw_do_enter_write+0xb7 sys/kern/kern_rwlock.c:233 rrw_enter(fffffd806f532b88,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:616 VOP_LOCK(fffffd805ddd1c28,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd805ddd1c28,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vfs_lookup(ffff80003a990908) at vfs_lookup+0x109 sys/kern/vfs_lookup.c:418 namei(ffff80003a990908) at namei+0x7aa sys/kern/vfs_lookup.c:250 unp_connect(ffff80000128e820,fffffd806a467500,ffff8000ffff6cd0) at unp_connect+0x27d sys/kern/uipc_usrreq.c:868 uipc_dgram_send(ffff80000128e820,fffffd806e67dd00,fffffd806a467500,0) at uipc_dgram_send+0x131 sys/kern/uipc_usrreq.c:607 sosend(ffff80000128e820,fffffd806a467500,ffff80003a990b88,0,0,0) at sosend+0x804 sendit(ffff8000ffff6cd0,3,ffff80003a990d00,0,ffff80003a990dc0) at sendit+0x721 sys/kern/uipc_syscalls.c:779 sys_sendmsg(ffff8000ffff6cd0,ffff80003a990e70,ffff80003a990dc0) at sys_sendmsg+0x246 sys/kern/uipc_syscalls.c:597 syscall(ffff80003a990e70) at syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003a990e70) at syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xb5e72100270, count: -15 ddb{0}> show registers rdi 0 rsi 0x80000 acpi_pdirpa+0x6be71 rbp 0xffff80003a990580 rbx 0xfffffd800433f9b0 rdx 0xffff80000129dd00 rcx 0xffff8000ffff6cd0 rax 0x7ffff acpi_pdirpa+0x6be70 r8 0xffff80003a990460 r9 0x8080808080808080 r10 0xc7837af813917d8a r11 0xf67d54f3208c1938 r12 0 r13 0xfffffd8003b56f00 r14 0x3 r15 0xffffffff rip 0xffffffff82a6fbd5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003a990570 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=233402 pid=581 tcnt=2 stat=onproc flags process=0 proc=4000000 runpri=32, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000ffff6538,0xffff8000ffff7c10 process=0xffff80003c63c240 user=0xffff80003a98b000, vmspace=0xfffffd806bfdaac8 estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 82512 147838 83713 0 2 0 syz-executor 33249 334621 1018 0 2 0 syz-executor 33249 47158 1018 0 3 0x4000080 fsleep syz-executor 33249 62167 1018 0 3 0x4000080 fsleep syz-executor 33249 91374 1018 0 3 0x4000080 fsleep syz-executor 581 486530 80119 0 7 0 syz-executor * 581 233402 80119 0 7 0x4000000 syz-executor 26955 446422 13042 0 2 0 syz-executor 26955 13033 13042 0 3 0x4000080 fsleep syz-executor 31556 221801 44619 0 2 0 syz-executor 31556 265671 44619 0 3 0x4000080 sbwait syz-executor 43131 520284 94866 0 2 0 syz-executor 43131 413375 94866 0 3 0x4000080 fsleep syz-executor 13561 424122 66126 0 2 0 syz-executor 13561 21609 66126 0 3 0x4000080 netacc syz-executor 13561 424474 66126 0 3 0x4000080 fsleep syz-executor 77671 79110 0 0 3 0x14200 acct acct 44619 99664 14642 0 3 0x82 nanoslp syz-executor 50788 459040 1 0 3 0x100083 ttyin getty 82222 512070 0 0 3 0x14280 nfsidl nfsio 37894 122945 0 0 3 0x14280 nfsidl nfsio 82660 429848 0 0 3 0x14280 nfsidl nfsio 76595 163897 0 0 3 0x14280 nfsidl nfsio 48647 153516 0 0 3 0x14280 nfsidl nfsio 92247 296548 0 0 3 0x14280 nfsidl nfsio 88863 326335 0 0 3 0x14280 nfsidl nfsio 65118 152793 0 0 3 0x14280 nfsidl nfsio 28048 124206 0 0 3 0x14280 nfsidl nfsio 76004 305275 0 0 3 0x14280 nfsidl nfsio 83427 269004 0 0 3 0x14280 nfsidl nfsio 16261 140401 0 0 3 0x14280 nfsidl nfsio 60853 500759 0 0 3 0x14280 nfsidl nfsio 29551 348888 0 0 3 0x14280 nfsidl nfsio 48464 207586 0 0 3 0x14280 nfsidl nfsio 86091 389833 0 0 3 0x14280 nfsidl nfsio 90723 264630 0 0 3 0x14280 nfsidl nfsio 20074 138221 0 0 3 0x14280 nfsidl nfsio 27619 227057 0 0 3 0x14280 nfsidl nfsio 96066 112751 0 0 3 0x14280 nfsidl nfsio 64894 134091 0 0 3 0x14200 bored sosplice 73025 102834 14642 0 3 0x82 piperd syz-executor 80119 72985 14642 0 3 0x82 nanoslp syz-executor 13042 80036 14642 0 3 0x82 nanoslp syz-executor 83713 459249 14642 0 3 0x82 nanoslp syz-executor 66126 333007 14642 0 3 0x82 nanoslp syz-executor 94866 282315 14642 0 3 0x82 nanoslp syz-executor 1018 118821 14642 0 3 0x82 nanoslp syz-executor 14642 304209 61461 0 2 0x2 syz-executor 61461 136558 34064 0 3 0x10008a sigsusp ksh 34064 52095 85200 0 3 0x98 kqread sshd-session 85200 494985 77391 0 3 0x92 kqread sshd-session 77391 43472 1 0 3 0x88 kqread sshd 93570 515115 87092 74 3 0x1100092 bpf pflogd 87092 461948 1 0 3 0x80 sbwait pflogd 37726 114068 85016 73 3 0x1100090 kqread syslogd 85016 62462 1 0 3 0x100082 sbwait syslogd 10316 51506 1 0 3 0x100080 kqread resolvd 35161 199125 53751 77 3 0x100092 kqread dhcpleased 94501 332420 53751 77 3 0x100092 kqread dhcpleased 53751 480496 1 0 3 0x80 kqread dhcpleased 71339 426530 0 0 3 0x14200 bored smr 96076 518244 0 0 2 0x14200 zerothread 94974 474484 0 0 3 0x14200 aiodoned aiodoned 21077 242931 0 0 3 0x14200 syncer update 67101 371077 0 0 3 0x14200 cleaner cleaner 88974 374903 0 0 3 0x14200 reaper reaper 46652 121027 0 0 3 0x14200 pgdaemon pagedaemon 94932 481969 0 0 3 0x14200 bored viomb 15506 170042 0 0 3 0x40014200 acpi0 acpi0 82761 39441 0 0 3 0x40014200 idle1 89317 423779 0 0 3 0x14200 bored softnet3 3967 112942 0 0 3 0x14200 bored softnet2 93825 280937 0 0 3 0x14200 bored softnet1 4418 173775 0 0 3 0x14200 bored softnet0 92798 5351 0 0 3 0x14200 bored systqmp 23715 220010 0 0 3 0x14200 bored systq 89058 53866 0 0 3 0x14200 tmoslp softclockmp 46779 401680 0 0 3 0x40014200 tmoslp softclock 79803 46634 0 0 3 0x40014200 idle0 1 345985 0 0 3 0x80082 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 581 (syz-executor) thread 0xffff8000ffff6cd0 (233402) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8360db10) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1155 #1 unp_connect+0x26c sys/kern/uipc_usrreq.c:868 #2 uipc_dgram_send+0x131 sys/kern/uipc_usrreq.c:607 #3 sosend+0x804 #4 sendit+0x721 sys/kern/uipc_syscalls.c:779 #5 sys_sendmsg+0x246 sys/kern/uipc_syscalls.c:597 #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 exclusive rwlock sbufsnd r = 0 (0xffff80000128e9e0) #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:537 #3 sosend+0x2e2 sys/kern/uipc_socket.c:625 #4 sendit+0x721 sys/kern/uipc_syscalls.c:779 #5 sys_sendmsg+0x246 sys/kern/uipc_syscalls.c:597 #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 11290K 11453K 166960K 12967 0 pcb 17 14K 16K 166960K 295 0 rtable 193 7K 8K 166960K 493 0 pf 34 17K 19K 166960K 78 0 ifaddr 36 5K 7K 166960K 69 0 ifgroup 55 2K 2K 166960K 90 0 sysctl 3 1K 2K 166960K 7 0 counters 64 36K 36K 166960K 90 0 ioctlops 0 0K 4K 166960K 1625 0 iov 0 0K 16K 166960K 126 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1397 88K 88K 166960K 2168 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 9K 166960K 24 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 91 0 dirhash 12 2K 3K 166960K 36 0 ACPI 1690 195K 286K 166960K 12468 0 file desc 17 61K 81K 166960K 1129 0 sigio 0 0K 0K 166960K 23 0 proc 77 115K 128K 166960K 685 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 1 0K 0K 166960K 109 0 in_multi 75 5K 7K 166960K 156 0 ether_multi 1 0K 0K 166960K 6 0 mrt 2 0K 0K 166960K 5 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 550 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 225 72K 86K 166960K 12267 0 UVM aobj 7 2K 2K 166960K 7 0 pinsyscall 42 84K 99K 166960K 2301 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 75 0 NDP 12 0K 2K 166960K 46 0 temp 66 6897K 7147K 166960K 36308 0 kqueue 13 20K 37K 166960K 207 0 SYN cache 2 8K 16K 166960K 3 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 120 175 0 172 3 2 1 3 0 8 0 rtentry 112 148 0 63 4 0 4 4 0 8 0 unpcb 144 634 0 611 5 3 2 4 0 8 1 syncache 336 10 0 10 4 3 1 1 0 8 1 tcpcb 808 408 0 403 14 7 7 8 0 8 6 arp 120 23 0 9 1 0 1 1 0 8 0 inpcb 376 1256 0 1244 14 7 7 8 0 8 5 nd6 136 33 0 16 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 0 1 1 0 8 1 kcovpl 48 9 0 1 1 0 1 1 0 8 0 ppxss 1168 9 0 9 3 2 1 1 0 8 1 pffrag 232 3 0 1 1 0 1 1 0 482 0 pffrnode 88 3 0 1 1 0 1 1 0 8 0 pffrent 40 7 0 5 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 84 0 29 1 0 1 1 0 8 0 pfstkey 128 84 0 29 2 0 2 2 0 8 0 pfstate 376 84 0 29 7 1 6 6 0 8 0 pfrule 1344 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 579 0 220 31 6 25 31 0 8 0 art_table 32 581 0 220 4 0 4 4 0 8 0 art_node 16 143 0 65 1 0 1 1 0 8 0 sysvmsgpl 40 17 0 11 1 0 1 1 0 8 0 semapl 112 82 0 72 1 0 1 1 0 8 0 shmpl 112 4 0 0 1 0 1 1 0 8 0 dirhash 1024 33 0 16 3 0 3 3 0 8 0 dino2pl 256 3324 0 1814 95 0 95 95 0 8 0 ffsino 280 3324 0 1814 109 0 109 109 0 8 0 nchpl 144 4943 0 3252 63 0 63 63 0 8 0 uvmvnodes 80 3946 0 0 81 0 81 81 0 8 0 vnodes 216 3946 0 0 220 0 220 220 0 8 0 namei 1024 17307 0 17306 1 0 1 1 0 8 0 percpumem 16 59 0 13 1 0 1 1 0 8 0 kstatmem 264 50 0 26 2 0 2 2 0 8 0 scsiplug 72 3 0 3 2 1 1 1 0 8 1 scxspl 216 14564 0 14564 13 12 1 8 1 8 1 plimitpl 152 261 0 243 1 0 1 1 0 8 0 sigapl 424 1464 0 1393 11 2 9 9 0 8 0 futexpl 64 16850 0 16844 1 0 1 1 0 8 0 knotepl 120 381 0 0 12 0 12 12 0 8 0 kqueuepl 216 388 0 378 7 6 1 5 0 8 0 pipepl 328 296 0 269 7 4 3 6 0 8 0 fdescpl 504 1424 0 1393 5 0 5 5 0 8 0 filepl 152 8748 0 8523 16 3 13 14 0 8 3 lockfpl 104 387 0 385 1 0 1 1 0 8 0 lockfspl 48 141 0 139 1 0 1 1 0 8 0 sessionpl 144 31 0 22 1 0 1 1 0 8 0 pgrppl 48 54 0 37 1 0 1 1 0 8 0 ucredpl 104 1523 0 1510 1 0 1 1 0 8 0 zombiepl 144 1393 0 1393 1 0 1 1 0 8 1 processpl 1168 1464 0 1393 6 0 6 6 0 8 0 procpl 648 3091 0 3011 8 0 8 8 0 8 0 srpgc 96 4 0 4 2 2 0 1 0 8 0 sosppl 168 10 0 10 2 1 1 1 0 8 1 sockpl 688 2074 0 2036 21 13 8 15 0 8 4 mcl64k 65536 6 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 129 0 0 17 1 16 17 0 8 0 mcl2k 2048 34 0 0 5 0 5 5 0 8 0 mtagpl 96 83 0 0 3 0 3 3 0 8 0 mbufpl 256 320 0 0 19 0 19 19 0 8 0 bufpl 280 3976 0 133 275 0 275 275 0 8 0 anonpl 24 202210 0 198732 67 16 51 56 0 185 18 amapchunkpl 152 39146 0 38659 29 6 23 26 0 158 1 amappl16 200 4065 0 4035 42 31 11 21 0 8 8 amappl15 192 3 0 3 1 1 0 1 0 8 0 amappl14 184 129 0 117 1 0 1 1 0 8 0 amappl13 176 1 0 1 1 1 0 1 0 8 0 amappl12 168 2099 0 2068 3 1 2 2 0 8 0 amappl11 160 51 0 37 1 0 1 1 0 8 0 amappl10 152 8 0 8 2 2 0 1 0 8 0 amappl9 144 249 0 249 1 1 0 1 0 8 0 amappl8 136 27 0 24 1 0 1 1 0 8 0 amappl7 128 127 0 115 1 0 1 1 0 8 0 amappl6 120 191 0 187 1 0 1 1 0 8 0 amappl5 112 131 0 120 1 0 1 1 0 8 0 amappl4 104 359 0 340 1 0 1 1 0 8 0 amappl3 96 7968 0 7855 4 0 4 4 0 8 0 amappl2 88 739 0 677 2 0 2 2 0 8 0 amappl1 80 12498 0 11927 14 0 14 14 0 8 0 amappl 88 11751 0 11582 5 0 5 5 0 92 0 dma32768 32768 1 0 1 1 0 1 1 0 8 1 dma8192 8192 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 128 254 0 254 2 1 1 1 0 8 1 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 6 0 0 1 0 1 1 0 8 0 uaddrrnd 24 1424 0 1393 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1424 0 1393 1 0 1 1 0 8 0 vmmpekpl 168 13388 0 13341 4 1 3 3 0 8 0 vmmpepl 168 92564 0 90702 101 8 93 98 0 357 6 vmsppl 456 1423 0 1393 7 2 5 5 0 8 0 rwobjpl 64 30469 0 25589 79 0 79 79 0 8 0 pdppl 4096 2855 0 2786 127 54 73 79 0 8 4 pvpl 32 16106 0 0 131 1 130 130 0 265 0 pmappl 248 1423 0 1393 3 0 3 3 0 8 0 extentpl 40 55 0 38 1 0 1 1 0 8 0 phpool 112 340 0 77 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:437 witness_checkorder(fffffd806f532ba0,9,0) at witness_checkorder+0x1047 rw_do_enter_write(fffffd806f532b88,1) at rw_do_enter_write+0xb7 sys/kern/kern_rwlock.c:233 rrw_enter(fffffd806f532b88,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:616 VOP_LOCK(fffffd805ddd1c28,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd805ddd1c28,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vfs_lookup(ffff80003a990908) at vfs_lookup+0x109 sys/kern/vfs_lookup.c:418 namei(ffff80003a990908) at namei+0x7aa sys/kern/vfs_lookup.c:250 unp_connect(ffff80000128e820,fffffd806a467500,ffff8000ffff6cd0) at unp_connect+0x27d sys/kern/uipc_usrreq.c:868 uipc_dgram_send(ffff80000128e820,fffffd806e67dd00,fffffd806a467500,0) at uipc_dgram_send+0x131 sys/kern/uipc_usrreq.c:607 sosend(ffff80000128e820,fffffd806a467500,ffff80003a990b88,0,0,0) at sosend+0x804 sendit(ffff8000ffff6cd0,3,ffff80003a990d00,0,ffff80003a990dc0) at sendit+0x721 sys/kern/uipc_syscalls.c:779 sys_sendmsg(ffff8000ffff6cd0,ffff80003a990e70,ffff80003a990dc0) at sys_sendmsg+0x246 sys/kern/uipc_syscalls.c:597 syscall(ffff80003a990e70) at syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003a990e70) at syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xb5e72100270, count: -15 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp ddb{1}> trace x86_ipi_db(ffff800029b5bff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:393 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(ffffffff8360d908) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff8360d908) at __mp_lock+0x192 sys/kern/kern_lock.c:144 syscall(ffff80003c5a6ef0) at syscall+0xae6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c5a6ef0) at syscall+0xae6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7601f249bf60, count: -6