witness: lock order reversal: 1st 0xfffffd806bcfa4a0 vmmaplk (&map->lock) 2nd 0xfffffd806536ef88 inode (&ip->i_lock) lock order [1] vmmaplk (&map->lock) -> [2] inode (&ip->i_lock) #0 rw_enter+0x122 #1 rrw_enter+0xbe sys/kern/kern_rwlock.c:464 #2 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 #3 vn_lock+0xa4 sys/kern/vfs_vnops.c:564 #4 vn_rdwr+0xd1 sys/kern/vfs_vnops.c:320 #5 vndstrategy+0x4ff sys/dev/vnd.c:342 #6 physio+0x2f6 sys/kern/kern_physio.c:162 #7 spec_read+0x155 sys/kern/spec_vnops.c:215 #8 VOP_READ+0x102 sys/kern/vfs_vops.c:227 #9 vn_read+0x17b sys/kern/vfs_vnops.c:369 #10 dofilereadv+0x230 sys/kern/sys_generic.c:252 #11 sys_readv+0xd8 sys/kern/sys_generic.c:199 #12 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:178 [inline] #12 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #13 Xsyscall+0x128 lock order [2] inode (&ip->i_lock) -> [1] vmmaplk (&map->lock) #0 rw_enter_read+0xab sys/kern/kern_rwlock.c:112 #1 uvmfault_lookup+0x122 sys/uvm/uvm_fault.c:1819 #2 uvm_fault_check+0x49 sys/uvm/uvm_fault.c:672 #3 uvm_fault+0xf5 sys/uvm/uvm_fault.c:600 #4 kpageflttrap+0x2d0 sys/arch/amd64/amd64/trap.c:279 #5 kerntrap+0x14a sys/arch/amd64/amd64/trap.c:332 #6 alltraps_kern_meltdown+0x7b #7 copyout+0x57 #8 ffs_read+0x422 sys/ufs/ffs/ffs_vnops.c:254 #9 VOP_READ+0x102 sys/kern/vfs_vops.c:227 #10 vn_rdwr+0x15b #11 vmcmd_map_readvn+0x142 sys/kern/exec_subr.c:249 #12 exec_process_vmcmds+0xfb sys/kern/exec_subr.c:139 #13 sys_execve+0xbe4 sys/kern/kern_exec.c:468 #14 start_init+0x3c6 sys/kern/init_main.c:714 #15 proc_trampoline+0x10 Stopped at db_enter+0x25: addq $0x8,%rsp ddb{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic the kernel did not panic ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(fffffd806536ef88,9,0) at witness_checkorder+0x1047 rw_enter(fffffd806536ef78,1) at rw_enter+0x122 rrw_enter(fffffd806536ef78,1) at rrw_enter+0xbe sys/kern/kern_rwlock.c:464 VOP_LOCK(fffffd805eb96a80,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd805eb96a80,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:564 vn_rdwr(0,fffffd805eb96a80,ffff800011a26440,3f,0,1,ce87ad3d0379edb2,0,ffff800000b3e000,0) at vn_rdwr+0xd1 sys/kern/vfs_vnops.c:320 vndstrategy(fffffd805f2a96d0) at vndstrategy+0x4ff sys/dev/vnd.c:342 physio(ffffffff820851c0,2902,8000,ffffffff8131b440,ffff80002df72750) at physio+0x2f6 sys/kern/kern_physio.c:162 spec_read(ffff80002df72540) at spec_read+0x155 sys/kern/spec_vnops.c:215 VOP_READ(fffffd806de93de0,ffff80002df72750,0,fffffd807f7d3548) at VOP_READ+0x102 sys/kern/vfs_vops.c:227 vn_read(fffffd805fb63140,ffff80002df72750,0) at vn_read+0x17b sys/kern/vfs_vnops.c:369 dofilereadv(ffff800035b95980,3,ffff80002df72750,0,ffff80002df72810) at dofilereadv+0x230 sys/kern/sys_generic.c:252 sys_readv(ffff800035b95980,ffff80002df728c0,ffff80002df72810) at sys_readv+0xd8 sys/kern/sys_generic.c:199 syscall(ffff80002df728c0) at syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:178 [inline] syscall(ffff80002df728c0) at syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xffdd6ea700, count: -16 ddb{1}> show registers rdi 0 rsi 0x40000 acpi_pdirpa+0x2be71 rbp 0xffff80002df72000 rbx 0xfffffd80042c72d8 rdx 0xffff8000012a3700 rcx 0xffff800035b95980 rax 0x3ffff acpi_pdirpa+0x2be70 r8 0xffff80002df71ee0 r9 0x8080808080808080 r10 0x389a8eb837a2d3b4 r11 0x8ba7ca9c9d8d230e r12 0 r13 0xfffffd8003adfe00 r14 0x3 r15 0xffffffff rip 0xffffffff812ecd15 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002df71ff0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=466847 pid=93145 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=0xffff800035b95470,0xffffffff83509350 process=0xffff8000371fa8c8 user=0xffff80002df6d000, vmspace=0xfffffd806bcfa3a8 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 93145 495366 25924 0 7 0 syz-executor *93145 466847 25924 0 7 0x4000000 syz-executor 98427 315426 64327 0 2 0x2 syz-executor 51098 436002 67372 0 3 0x80 nanoslp syz-executor 51098 424404 67372 0 3 0x4000080 sbwait syz-executor 51098 104954 67372 0 3 0x4000080 sbwait syz-executor 51098 127096 67372 0 3 0x4000080 fsleep syz-executor 67372 154181 64327 0 3 0x82 nanoslp syz-executor 80333 1947 64327 0 3 0x82 piperd syz-executor 48530 509897 0 0 3 0x14200 acct acct 94672 68107 0 0 3 0x14280 nfsidl nfsio 79416 427940 0 0 3 0x14280 nfsidl nfsio 9366 413782 0 0 3 0x14280 nfsidl nfsio 40251 421991 0 0 3 0x14280 nfsidl nfsio 26557 496840 0 0 3 0x14280 nfsidl nfsio 58712 519965 0 0 3 0x14280 nfsidl nfsio 68092 466515 0 0 3 0x14280 nfsidl nfsio 82731 499775 0 0 3 0x14280 nfsidl nfsio 13444 223097 0 0 3 0x14280 nfsidl nfsio 49923 281147 0 0 3 0x14280 nfsidl nfsio 65095 185220 0 0 3 0x14280 nfsidl nfsio 70772 189060 0 0 3 0x14280 nfsidl nfsio 42310 443820 0 0 3 0x14280 nfsidl nfsio 6673 270691 0 0 3 0x14280 nfsidl nfsio 19744 432329 0 0 3 0x14280 nfsidl nfsio 85969 351230 0 0 3 0x14280 nfsidl nfsio 71986 321981 0 0 3 0x14280 nfsidl nfsio 7855 212003 0 0 3 0x14280 nfsidl nfsio 57695 249334 0 0 3 0x14280 nfsidl nfsio 39530 64298 0 0 3 0x14280 nfsidl nfsio 91934 160429 0 0 3 0x14200 bored sosplice 68640 512811 31510 0 3 0x100082 sbwait ndp 31510 15874 50999 0 3 0x10008a sigsusp sh 25924 421702 64327 0 3 0x82 nanoslp syz-executor 50999 50202 64327 0 3 0x82 wait syz-executor 45003 30026 64327 0 3 0x82 piperd syz-executor 95343 483759 64327 0 3 0x82 nanoslp syz-executor 64327 444246 61021 0 3 0x82 nanoslp syz-executor 61021 379439 61390 0 3 0x10008a sigsusp ksh 61390 223413 29060 0 3 0x98 kqread sshd-session 29060 482585 77882 0 3 0x92 kqread sshd-session 59761 51706 1 0 3 0x100083 ttyin getty 77882 262122 1 0 3 0x88 kqread sshd 93779 166662 5249 74 3 0x1100092 bpf pflogd 5249 3972 1 0 3 0x80 sbwait pflogd 96522 419952 51168 73 3 0x1100090 kqread syslogd 51168 369840 1 0 3 0x100082 sbwait syslogd 38902 288555 1 0 3 0x100080 kqread resolvd 28174 239083 99784 77 3 0x100092 kqread dhcpleased 70301 484610 99784 77 3 0x100092 kqread dhcpleased 99784 20495 1 0 3 0x80 kqread dhcpleased 59980 338905 0 0 3 0x14200 bored smr 12594 283118 0 0 2 0x14200 zerothread 56949 81360 0 0 3 0x14200 aiodoned aiodoned 19954 160952 0 0 3 0x14200 syncer update 24925 343089 0 0 3 0x14200 cleaner cleaner 87092 201836 0 0 3 0x14200 reaper reaper 55984 482408 0 0 3 0x14200 pgdaemon pagedaemon 19464 399015 0 0 3 0x14200 bored viomb 58801 151256 0 0 3 0x40014200 acpi0 acpi0 17457 141387 0 0 3 0x40014200 idle1 37067 311656 0 0 3 0x14200 bored softnet3 62068 169444 0 0 3 0x14200 bored softnet2 98003 117596 0 0 3 0x14200 bored softnet1 97894 441731 0 0 3 0x14200 bored softnet0 61291 86368 0 0 3 0x14200 bored systqmp 57823 173900 0 0 3 0x14200 bored systq 19157 334686 0 0 3 0x14200 tmoslp softclockmp 97229 29073 0 0 3 0x40014200 tmoslp softclock 79165 116191 0 0 3 0x40014200 idle0 1 295855 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 93145 (syz-executor) thread 0xffff800035b95980 (466847) shared rwlock vmmaplk r = 0 (0xfffffd806bcfa4a0) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1155 #1 uvm_vslock_device+0x149 sys/uvm/uvm_glue.c:172 #2 physio+0x277 sys/kern/kern_physio.c:139 #3 spec_read+0x155 sys/kern/spec_vnops.c:215 #4 VOP_READ+0x102 sys/kern/vfs_vops.c:227 #5 vn_read+0x17b sys/kern/vfs_vnops.c:369 #6 dofilereadv+0x230 sys/kern/sys_generic.c:252 #7 sys_readv+0xd8 sys/kern/sys_generic.c:199 #8 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:178 [inline] #8 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #9 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff836258d8) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1155 #1 vn_read+0x56 sys/kern/vfs_vnops.c:351 #2 dofilereadv+0x230 sys/kern/sys_generic.c:252 #3 sys_readv+0xd8 sys/kern/sys_generic.c:199 #4 syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:178 [inline] #4 syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 #5 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10188 11112K 11575K 166960K 12902 0 pcb 17 13K 14K 166960K 177 0 rtable 141 5K 6K 166960K 777 0 pf 32 17K 19K 166960K 86 0 ifaddr 30 4K 7K 166960K 105 0 ifgroup 47 2K 2K 166960K 106 0 sysctl 3 0K 0K 166960K 5 0 counters 60 35K 36K 166960K 94 0 ioctlops 0 0K 4K 166960K 1558 0 iov 1 0K 24K 166960K 113 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1432 90K 90K 166960K 2601 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 9K 166960K 18 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 29 0 dirhash 12 2K 2K 166960K 33 0 ACPI 1690 195K 286K 166960K 12468 0 file desc 14 49K 93K 166960K 1123 0 sigio 0 0K 0K 166960K 10 0 proc 72 91K 140K 166960K 656 0 subproc 79 4K 6K 166960K 612 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 250 0 in_multi 55 4K 7K 166960K 350 0 ether_multi 1 0K 0K 166960K 9 0 mrt 0 0K 0K 166960K 4 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 566 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 210 56K 81K 166960K 11497 0 UVM aobj 63 5K 5K 166960K 65 0 pinsyscall 40 80K 105K 166960K 2289 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 34 0 NDP 10 0K 1K 166960K 81 0 temp 66 6826K 6927K 166960K 40030 0 kqueue 14 20K 28K 166960K 147 0 SYN cache 2 16K 16K 166960K 2 0 ddb{1}> 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 120 103 0 99 1 0 1 1 0 8 0 rtentry 112 290 0 230 4 0 4 4 0 8 0 unpcb 144 905 0 886 12 8 4 6 0 8 3 syncache 336 12 0 12 5 5 0 1 0 8 0 tcpqe 32 3 0 3 3 3 0 1 0 8 0 tcpcb 808 326 0 319 11 10 1 8 0 8 0 arp 120 28 0 14 1 0 1 1 0 8 0 inpcb 336 1042 0 1032 14 12 2 7 0 8 0 nd6 136 68 0 56 1 0 1 1 0 8 0 pkpcb 40 6 0 6 3 2 1 1 0 8 1 kcovpl 48 47 0 41 1 0 1 1 0 8 0 ppxss 1168 7 0 7 3 3 0 1 0 8 0 pfstscr 40 2 0 2 1 1 0 1 0 8 0 pffrag 232 4 0 1 1 0 1 1 0 482 0 pffrnode 88 4 0 1 1 0 1 1 0 8 0 pffrent 40 49 0 46 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 84 0 36 1 0 1 1 0 8 0 pfstkey 128 88 0 40 2 0 2 2 0 8 0 pfstate 376 86 0 38 6 0 6 6 0 8 0 pfrule 1344 23 0 17 2 0 2 2 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 1423 0 1162 29 2 27 29 0 8 5 art_table 32 1425 0 1162 4 0 4 4 0 8 0 art_node 16 284 0 233 1 0 1 1 0 8 0 sysvmsgpl 40 17 0 8 2 1 1 1 0 8 0 semapl 112 27 0 17 1 0 1 1 0 8 0 shmpl 112 62 0 2 2 0 2 2 0 8 0 dirhash 1024 31 0 14 3 0 3 3 0 8 0 dino2pl 256 3104 0 1560 97 0 97 97 0 8 0 ffsino 272 3104 0 1560 104 1 103 103 0 8 0 nchpl 144 4527 0 2806 64 0 64 64 0 8 0 uvmvnodes 80 4206 0 0 86 0 86 86 0 8 0 vnodes 216 4206 0 0 234 0 234 234 0 8 0 namei 1024 15393 0 15393 4 3 1 2 0 8 1 percpumem 16 61 0 17 1 0 1 1 0 8 0 kstatmem 264 54 0 34 2 0 2 2 0 8 0 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 1 0 1 1 1 0 1 0 8 0 scxspl 216 22454 0 22454 10 9 1 8 1 8 1 plimitpl 152 245 0 229 1 0 1 1 0 8 0 sigapl 424 1372 0 1304 10 1 9 9 0 8 0 futexpl 64 13719 0 13718 2 1 1 1 0 8 0 knotepl 120 541 0 0 17 0 17 17 0 8 0 kqueuepl 216 249 0 239 1 0 1 1 0 8 0 pipepl 320 320 0 293 3 0 3 3 0 8 0 fdescpl 496 1332 0 1304 5 0 5 5 0 8 0 filepl 152 8382 0 8162 25 13 12 20 0 8 1 lockfpl 104 475 0 473 2 1 1 2 0 8 0 lockfspl 48 143 0 141 1 0 1 1 0 8 0 sessionpl 144 70 0 61 1 0 1 1 0 8 0 pgrppl 48 119 0 103 1 0 1 1 0 8 0 ucredpl 104 990 0 975 1 0 1 1 0 8 0 zombiepl 144 1305 0 1304 1 0 1 1 0 8 0 processpl 1160 1372 0 1304 6 0 6 6 0 8 0 procpl 648 2822 0 2750 9 1 8 8 0 8 1 srpgc 96 4 0 4 1 1 0 1 0 8 0 sosppl 168 7 0 7 1 1 0 1 0 8 0 sockpl 664 2067 0 2034 28 18 10 15 0 8 6 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl16k 16384 3 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 9 0 0 2 0 2 2 0 8 0 mcl4k 4096 154 0 0 20 0 20 20 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 49 0 0 6 0 6 6 0 8 0 mtagpl 96 79 0 0 2 0 2 2 0 8 0 mbufpl 256 346 0 0 22 0 22 22 0 8 0 bufpl 280 8502 0 2327 442 0 442 442 0 8 0 anonpl 24 260057 0 256285 67 12 55 62 0 185 18 amapchunkpl 152 37952 0 37515 40 7 33 33 0 158 12 amappl16 200 6336 0 6317 31 25 6 15 0 8 2 amappl15 192 11 0 11 1 1 0 1 0 8 0 amappl14 184 154 0 141 1 0 1 1 0 8 0 amappl13 176 12 0 12 1 1 0 1 0 8 0 amappl12 168 2054 0 2025 4 1 3 3 0 8 0 amappl11 160 53 0 39 1 0 1 1 0 8 0 amappl10 152 8 0 8 1 1 0 1 0 8 0 amappl9 144 144 0 144 1 1 0 1 0 8 0 amappl8 136 29 0 26 1 0 1 1 0 8 0 amappl7 128 116 0 103 1 0 1 1 0 8 0 amappl6 120 195 0 193 1 0 1 1 0 8 0 amappl5 112 152 0 140 1 0 1 1 0 8 0 amappl4 104 370 0 348 1 0 1 1 0 8 0 amappl3 96 6820 0 6737 3 0 3 3 0 8 0 amappl2 88 1712 0 1629 3 0 3 3 0 8 0 amappl1 80 12712 0 12127 15 1 14 15 0 8 0 amappl 88 10963 0 10816 5 0 5 5 0 92 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 6 0 6 1 1 0 1 0 8 0 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 19 0 18 1 0 1 1 0 8 0 aobjpl 72 64 0 2 2 0 2 2 0 8 0 uaddrrnd 24 1332 0 1304 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1332 0 1304 1 0 1 1 0 8 0 vmmpekpl 168 14093 0 14034 4 0 4 4 0 8 0 vmmpepl 168 93564 0 91868 111 19 92 99 0 357 4 vmsppl 448 1331 0 1304 6 2 4 5 0 8 0 rwobjpl 56 33116 0 27914 77 3 74 74 0 8 0 pdppl 4096 2671 0 2608 115 48 67 85 0 8 4 pvpl 32 27036 0 0 218 0 218 218 0 265 0 pmappl 248 1331 0 1304 3 0 3 3 0 8 0 extentpl 40 55 0 38 1 0 1 1 0 8 0 phpool 112 448 0 88 11 0 11 11 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp ddb{0}> trace x86_ipi_db(ffffffff8348eff0) 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(ffffffff836256d0) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff836256d0) at __mp_lock+0x192 sys/kern/kern_lock.c:144 intr_handler(ffff80002a095fe0,ffff800000069c00) at intr_handler+0xe1 sys/arch/amd64/amd64/intr.c:553 Xintr_ioapic_edge16_untramp() at Xintr_ioapic_edge16_untramp+0x18f __mp_lock(ffffffff836256d0) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff836256d0) at __mp_lock+0x192 sys/kern/kern_lock.c:144 intr_handler(ffff80002a096140,ffff800000079e00) at intr_handler+0xe1 sys/arch/amd64/amd64/intr.c:553 Xintr_ioapic_edge25_untramp() at Xintr_ioapic_edge25_untramp+0x18f __mp_lock(ffffffff836256d0) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff836256d0) at __mp_lock+0x192 sys/kern/kern_lock.c:144 softintr_dispatch(0) at softintr_dispatch+0x5b sys/arch/amd64/amd64/softintr.c:88 Xsoftclock() at Xsoftclock+0x27 end of kernel end trace frame: 0x7c667dcd4790, count: -12 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x25: addq $0x8,%rsp ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(fffffd806536ef88,9,0) at witness_checkorder+0x1047 rw_enter(fffffd806536ef78,1) at rw_enter+0x122 rrw_enter(fffffd806536ef78,1) at rrw_enter+0xbe sys/kern/kern_rwlock.c:464 VOP_LOCK(fffffd805eb96a80,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd805eb96a80,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:564 vn_rdwr(0,fffffd805eb96a80,ffff800011a26440,3f,0,1,ce87ad3d0379edb2,0,ffff800000b3e000,0) at vn_rdwr+0xd1 sys/kern/vfs_vnops.c:320 vndstrategy(fffffd805f2a96d0) at vndstrategy+0x4ff sys/dev/vnd.c:342 physio(ffffffff820851c0,2902,8000,ffffffff8131b440,ffff80002df72750) at physio+0x2f6 sys/kern/kern_physio.c:162 spec_read(ffff80002df72540) at spec_read+0x155 sys/kern/spec_vnops.c:215 VOP_READ(fffffd806de93de0,ffff80002df72750,0,fffffd807f7d3548) at VOP_READ+0x102 sys/kern/vfs_vops.c:227 vn_read(fffffd805fb63140,ffff80002df72750,0) at vn_read+0x17b sys/kern/vfs_vnops.c:369 dofilereadv(ffff800035b95980,3,ffff80002df72750,0,ffff80002df72810) at dofilereadv+0x230 sys/kern/sys_generic.c:252 sys_readv(ffff800035b95980,ffff80002df728c0,ffff80002df72810) at sys_readv+0xd8 sys/kern/sys_generic.c:199 syscall(ffff80002df728c0) at syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:178 [inline] syscall(ffff80002df728c0) at syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xffdd6ea700, count: -16