witness: lock order reversal: 1st 0xffff8000014cca38 sbufrcv (&so->so_rcv.sb_lock) 2nd 0xfffffd806ff870b8 inode (&ip->i_lock) lock order [1] sbufrcv (&so->so_rcv.sb_lock) -> [2] inode (&ip->i_lock) lock order data 0xffffffff83329e49 -> 0xffffffff8337681c is missing lock order [2] inode (&ip->i_lock) -> [1] sbufrcv (&so->so_rcv.sb_lock) #0 rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 #1 sblock+0xb6 sys/kern/uipc_socket2.c:536 #2 soreceive+0x27d sys/kern/uipc_socket.c:878 #3 fifo_read+0x117 sys/miscfs/fifofs/fifo_vnops.c:264 #4 VOP_READ+0x101 sys/kern/vfs_vops.c:227 #5 vn_rdwr+0x15b sys/kern/vfs_vnops.c:-1 #6 vndsetcred+0xa1 sys/dev/vnd.c:685 #7 vndioctl+0xdfc sys/dev/vnd.c:486 #8 VOP_IOCTL+0xac sys/kern/vfs_vops.c:264 #9 vn_ioctl+0xf8 sys/kern/vfs_vnops.c:531 #10 sys_ioctl+0x674 sys/kern/sys_generic.c:-1 #11 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #11 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #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(fffffd806ff870b8,9,0) at witness_checkorder+0x10b9 sys/kern/subr_witness.c:-1 rw_do_enter_write(fffffd806ff870a0,1) at rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 rrw_enter(fffffd806ff870a0,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 VOP_LOCK(fffffd80738ebe78,2001) at VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 vn_lock(fffffd80738ebe78,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vfs_getcwd_common(fffffd80738ebe78,fffffd806ea7c1c8,0,0,200,0,429bf57ff09d7df2) at vfs_getcwd_common+0xd1 sys/kern/vfs_getcwd.c:287 vn_isunder(fffffd80738ebe78,fffffd806ea7c1c8,ffff80002a271ca0) at vn_isunder+0x56 sys/kern/vfs_vnops.c:694 unp_externalize(fffffd805d0b0100,33,0) at unp_externalize+0x26f sys/kern/uipc_usrreq.c:1090 soreceive(ffff8000014cc948,ffff80003c458ed8,ffff80003c458e88,0,ffff80003c458ec0,ffff80003c45904c,dcf706f2656ef1bb) at soreceive+0xc24 sys/kern/uipc_socket.c:1017 recvit(ffff80002a271ca0,5,ffff80003c459020,0,ffff80003c4590d0) at recvit+0x40b sys/kern/uipc_syscalls.c:1078 sys_recvmsg(ffff80002a271ca0,ffff80003c459180,ffff80003c4590d0) at sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:878 syscall(ffff80003c459180) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c459180) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x680ea540130, count: -14 ddb{0}> show registers rdi 0 rsi 0 rbp 0xffff80003c458970 rbx 0 rdx 0 rcx 0xffff80002a271ca0 rax 0xffffffff83884ff0 cpu_info_full_primary+0x1ff0 r8 0xffff80003c458850 r9 0x8080808080808080 r10 0xc95e604c61e24d6c r11 0x6956584b7fb8173e r12 0xfffffd8003f3c880 r13 0xfffffd8004724b48 r14 0x3 r15 0xffffffff8340ca16 substchar+0x822d rip 0xffffffff82bf18c5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003c458960 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=180401 pid=76921 tcnt=2 stat=onproc flags process=1000000 proc=4000000 runpri=32, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a270a78,0xffffffff8397df00 process=0xffff8000fffee1c8 user=0xffff80003c454000, vmspace=0xfffffd80698eb9a8 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 40876 288511 77689 0 2 0 syz-executor 40876 484288 77689 0 3 0x4000080 fsleep syz-executor 76921 299604 44148 0 2 0x1000000 syz-executor *76921 180401 44148 0 7 0x5000000 syz-executor 84942 63826 29579 0 7 0 syz-executor 84942 426487 29579 0 3 0x4000000 biowait syz-executor 66346 100385 90252 0 2 0 syz-executor 66346 29319 90252 0 3 0x4000080 fsleep syz-executor 4588 484780 99569 0 2 0x10 syz-executor 4588 168423 99569 0 3 0x4000090 fsleep syz-executor 41735 406207 66880 0 3 0x80 nanoslp syz-executor 41735 58942 66880 0 3 0x4000080 kqsel syz-executor 41735 10778 66880 0 3 0x4000080 fsleep syz-executor 29579 423780 66118 0 3 0x82 nanoslp syz-executor 40740 283974 0 0 3 0x14200 acct acct 58825 248256 66118 0 3 0x82 wait syz-executor 44148 350104 66118 0 3 0x82 nanoslp syz-executor 77689 109526 66118 0 3 0x82 nanoslp syz-executor 66880 466177 66118 0 3 0x82 nanoslp syz-executor 99569 128226 66118 0 2 0x2 syz-executor 38619 34154 66118 0 3 0x82 nanoslp syz-executor 90252 503488 66118 0 3 0x82 nanoslp syz-executor 66118 218138 8389 0 3 0x82 kqread syz-executor 8389 34463 89095 0 3 0x10008a sigsusp ksh 89095 228594 81368 0 3 0x98 kqread sshd-session 81368 341938 7546 0 3 0x92 kqread sshd-session 84261 412777 1 0 3 0x100083 ttyopn getty 7546 78309 1 0 3 0x88 kqread sshd 46416 116748 6480 74 3 0x1100092 bpf pflogd 6480 335570 1 0 3 0x80 sbwait pflogd 99129 493971 90315 73 3 0x1100090 kqread syslogd 90315 90254 1 0 3 0x100082 sbwait syslogd 89709 426613 1 0 3 0x100080 kqread resolvd 28786 225513 97175 77 3 0x100092 kqread dhcpleased 65259 116042 97175 77 3 0x100092 kqread dhcpleased 97175 382852 1 0 3 0x80 kqread dhcpleased 58828 402627 0 0 3 0x14200 bored smr 97035 340278 0 0 2 0x14200 zerothread 25781 298865 0 0 3 0x14200 aiodoned aiodoned 45689 103748 0 0 3 0x14200 syncer update 40533 477565 0 0 3 0x14200 cleaner cleaner 16009 59058 0 0 3 0x14200 reaper reaper 44678 218092 0 0 3 0x14200 pgdaemon pagedaemon 99966 134687 0 0 3 0x14200 bored viomb 47843 514646 0 0 3 0x40014200 acpi0 acpi0 58164 421812 0 0 3 0x40014200 idle1 82168 231229 0 0 3 0x14200 bored softnet1 84692 406155 0 0 3 0x14200 bored softnet0 55365 395490 0 0 3 0x14200 bored systqmp 59080 328828 0 0 3 0x14200 bored systq 44211 242074 0 0 3 0x14200 tmoslp softclockmp 45376 86014 0 0 3 0x40014200 tmoslp softclock 72296 354221 0 0 3 0x40014200 idle0 1 433459 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{0}> show all locks Process 76921 (syz-executor) thread 0xffff80002a271ca0 (180401) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83949d88) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 unp_externalize+0x155 sys/kern/uipc_usrreq.c:-1 #2 soreceive+0xc24 sys/kern/uipc_socket.c:1017 #3 recvit+0x40b sys/kern/uipc_syscalls.c:1078 #4 sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:878 #5 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #5 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #6 Xsyscall+0x128 exclusive rwlock sbufrcv r = 0 (0xffff8000014cca38) #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_recvmsg+0x1bf sys/kern/uipc_syscalls.c:878 #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 Process 84942 (syz-executor) thread 0xffff8000fffe9ca8 (426487) exclusive rrwlock inode r = 0 (0xfffffd80668b8908) #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:765 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10253 11127K 11988K 166960K 15187 0 pcb 18 16K 22K 166960K 709 0 rtable 212 12K 13K 166960K 910 0 pf 39 18K 23K 166960K 403 0 ifaddr 34 6K 8K 166960K 194 0 ifgroup 53 2K 2K 166960K 363 0 sysctl 4 1K 9K 166960K 40 0 counters 68 36K 38K 166960K 464 0 ioctlops 0 0K 4K 166960K 2337 0 iov 0 0K 20K 166960K 145 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1489 94K 94K 166960K 4037 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 9K 166960K 16 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 224 0 dirhash 12 2K 3K 166960K 60 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 110K 166960K 2704 0 sigio 0 0K 0K 166960K 57 0 proc 73 115K 180K 166960K 868 0 subproc 72 4K 4K 166960K 109 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 500 0 in_multi 66 4K 7K 166960K 243 0 ether_multi 1 0K 0K 166960K 18 0 mrt 33 2K 2K 166960K 50 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 247 1102K 1102K 166960K 247 0 exec 0 0K 1K 166960K 1209 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 5 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 270 176K 196K 166960K 26877 0 UVM aobj 19 12K 12K 166960K 23 0 pinsyscall 43 86K 104K 166960K 3933 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 198 0 NDP 12 0K 1K 166960K 140 0 temp 81 8676K 8932K 166960K 131713 0 kqueue 16 24K 34K 166960K 555 0 SYN cache 2 0K 16K 166960K 4 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 120 311 0 308 3 2 1 3 0 8 0 rtentry 176 279 0 201 6 0 6 6 0 8 0 unpcb 144 1777 0 1756 15 14 1 7 0 8 0 syncache 336 11 0 11 6 6 0 1 0 8 0 tcpqe 32 10 0 10 4 4 0 1 0 8 0 tcpcb 736 864 0 857 17 16 1 7 0 8 0 arp 136 32 0 18 1 0 1 1 0 8 0 inpcb 328 3116 0 3104 20 18 2 7 0 8 0 nd6 152 44 0 24 1 0 1 1 0 8 0 pkpcb 40 23 0 23 5 5 0 1 0 8 0 kcovpl 48 12 0 4 1 0 1 1 0 8 0 mppekey 1024 3 0 3 3 3 0 1 0 8 0 ppxss 1192 162 0 161 3 2 1 1 0 8 0 pppxif 1504 18 0 18 6 6 0 1 0 8 0 pfstscr 40 8 0 8 4 4 0 1 0 8 0 pffrag 232 39 0 32 1 0 1 1 0 482 0 pffrnode 88 17 0 10 1 0 1 1 0 8 0 pffrent 40 263 0 256 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 3 0 3 3 3 0 1 0 8 0 pfanchor 1288 1 0 1 1 1 0 1 0 8 0 pftag 88 3 0 0 1 0 1 1 0 8 0 pfstitem 24 155 0 101 1 0 1 1 0 8 0 pfstkey 128 164 0 111 3 0 3 3 0 8 0 pfstate 448 159 0 106 9 0 9 9 0 8 0 pfrule 1344 36 0 31 2 1 1 2 0 8 0 rttmr 136 2 0 2 2 2 0 1 0 8 0 art_heap8 4096 5 0 0 5 0 5 5 0 8 0 art_heap4 256 1045 0 715 32 8 24 30 0 8 0 art_table 40 1050 0 715 5 0 5 5 0 8 0 art_node 32 213 0 144 1 0 1 1 0 8 0 sysvmsgpl 40 22 0 11 1 0 1 1 0 8 0 semupl 112 4 0 4 3 3 0 1 0 8 0 semapl 112 218 0 208 1 0 1 1 0 8 0 shmpl 112 12 0 1 1 0 1 1 0 8 0 dirhash 1024 49 0 32 3 0 3 3 0 8 0 dino2pl 256 6591 0 5073 96 0 96 96 0 8 0 ffsino 296 6591 0 5073 119 1 118 118 0 8 0 nchpl 144 10358 0 9738 64 40 24 64 0 8 0 rtmask 32 33 0 33 5 5 0 1 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 36781 0 36781 3 2 1 2 0 8 1 percpumem 16 247 0 198 1 0 1 1 0 8 0 vcpupl 3968 6 0 1 1 0 1 1 0 8 0 vmpool 840 8 0 3 1 0 1 1 0 8 0 kstatmem 264 236 0 208 3 0 3 3 0 8 0 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 13 0 13 7 7 0 1 0 8 0 scxspl 216 59408 0 59407 12 11 1 6 1 8 0 plimitpl 152 653 0 635 1 0 1 1 0 8 0 sigapl 424 2998 0 2949 9 3 6 8 0 8 0 knotepl 120 785 0 0 24 0 24 24 0 8 0 kqueuepl 224 998 0 985 8 7 1 3 0 8 0 pipepl 344 386 0 359 6 3 3 6 0 8 0 fdescpl 528 2955 0 2923 3 0 3 3 0 8 0 filepl 160 20868 0 20577 29 14 15 19 0 8 1 lockfpl 104 1260 0 1258 2 1 1 2 0 8 0 lockfspl 48 492 0 490 1 0 1 1 0 8 0 sessionpl 144 34 0 25 1 0 1 1 0 8 0 pgrppl 48 119 0 102 1 0 1 1 0 8 0 ucredpl 104 3672 0 3658 1 0 1 1 0 8 0 zombiepl 144 3529 0 3527 2 1 1 1 0 8 0 processpl 1232 2998 0 2949 7 3 4 6 0 8 0 procpl 664 7371 0 7315 8 2 6 8 0 8 0 sosppl 176 27 0 27 6 6 0 1 0 8 0 sockpl 752 5385 0 5349 45 40 5 26 0 8 1 mcl64k 65536 11 0 0 2 0 2 2 0 8 0 mcl16k 16384 3 0 0 1 0 1 1 0 8 0 mcl12k 12288 5 0 0 1 0 1 1 0 8 0 mcl9k 9216 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 5 0 0 1 0 1 1 0 8 0 mcl4k 4096 123 0 0 16 0 16 16 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 57 0 0 7 0 7 7 0 8 0 mtagpl 96 67 0 0 2 0 2 2 0 8 0 mbufpl 256 1888 0 0 115 0 115 115 0 8 0 bufpl 280 23093 0 16956 439 0 439 439 0 8 0 anonpl 32 14033 0 0 114 1 113 113 0 246 0 amapchunkpl 152 94161 0 93506 51 24 27 38 0 158 0 amappl16 200 10281 0 10153 89 77 12 31 0 8 0 amappl15 192 3 0 3 1 1 0 1 0 8 0 amappl14 184 111 0 110 1 0 1 1 0 8 0 amappl13 176 477 0 475 1 0 1 1 0 8 0 amappl12 168 3365 0 3322 3 1 2 3 0 8 0 amappl11 160 3 0 3 1 1 0 1 0 8 0 amappl10 152 51 0 37 1 0 1 1 0 8 0 amappl9 144 254 0 254 1 1 0 1 0 8 0 amappl8 136 33 0 30 1 0 1 1 0 8 0 amappl7 128 128 0 126 1 0 1 1 0 8 0 amappl6 120 334 0 320 1 0 1 1 0 8 0 amappl5 112 88 0 76 1 0 1 1 0 8 0 amappl4 104 556 0 527 1 0 1 1 0 8 0 amappl3 96 16085 0 15982 4 1 3 3 0 8 0 amappl2 88 3132 0 3049 3 0 3 3 0 8 0 amappl1 80 22140 0 21545 15 1 14 14 0 8 0 amappl 88 25601 0 25411 5 0 5 5 0 92 0 uvmvnodes 80 193 0 0 4 0 4 4 0 8 0 dma65536 65536 1 0 1 1 1 0 1 0 8 0 dma32768 32768 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 dma512 512 1 0 1 1 1 0 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 258 0 258 5 5 0 1 0 8 0 dma64 64 8 0 8 3 3 0 1 0 8 0 dma32 32 9 0 9 3 3 0 1 0 8 0 dma16 16 20 0 19 1 0 1 1 0 8 0 aobjpl 72 22 0 4 1 0 1 1 0 8 0 uaddrrnd 24 2955 0 2923 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2955 0 2923 1 0 1 1 0 8 0 vmmpekpl 168 23642 0 23594 3 0 3 3 0 8 0 vmmpepl 168 193775 0 191659 130 32 98 112 0 357 0 vmsppl 488 2954 0 2923 6 1 5 5 0 8 0 rwobjpl 80 51201 0 49929 39 7 32 35 0 8 0 pdppl 4096 5933 0 5857 124 48 76 85 0 8 0 pvpl 32 23595 0 0 190 0 190 190 0 265 0 pmappl 256 2962 0 2926 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 449 0 88 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 witness_checkorder(fffffd806ff870b8,9,0) at witness_checkorder+0x10b9 sys/kern/subr_witness.c:-1 rw_do_enter_write(fffffd806ff870a0,1) at rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234 rrw_enter(fffffd806ff870a0,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 VOP_LOCK(fffffd80738ebe78,2001) at VOP_LOCK+0xa3 sys/kern/vfs_vops.c:527 vn_lock(fffffd80738ebe78,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vfs_getcwd_common(fffffd80738ebe78,fffffd806ea7c1c8,0,0,200,0,429bf57ff09d7df2) at vfs_getcwd_common+0xd1 sys/kern/vfs_getcwd.c:287 vn_isunder(fffffd80738ebe78,fffffd806ea7c1c8,ffff80002a271ca0) at vn_isunder+0x56 sys/kern/vfs_vnops.c:694 unp_externalize(fffffd805d0b0100,33,0) at unp_externalize+0x26f sys/kern/uipc_usrreq.c:1090 soreceive(ffff8000014cc948,ffff80003c458ed8,ffff80003c458e88,0,ffff80003c458ec0,ffff80003c45904c,dcf706f2656ef1bb) at soreceive+0xc24 sys/kern/uipc_socket.c:1017 recvit(ffff80002a271ca0,5,ffff80003c459020,0,ffff80003c4590d0) at recvit+0x40b sys/kern/uipc_syscalls.c:1078 sys_recvmsg(ffff80002a271ca0,ffff80003c459180,ffff80003c4590d0) at sys_recvmsg+0x1bf sys/kern/uipc_syscalls.c:878 syscall(ffff80003c459180) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c459180) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x680ea540130, count: -14 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp 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+0x33 kd_curproc sys/dev/kcov.c:585 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x33 sys/dev/kcov.c:153 __mp_lock(ffffffff83949b80) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff83949b80) at __mp_lock+0x1a3 sys/kern/kern_lock.c:165 syscall(ffff80003a3f8270) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] syscall(ffff80003a3f8270) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x756b305ce2e0, count: -7