witness: lock order reversal: 1st 0xfffffd806bfb4670 vmmaplk (&map->lock) 2nd 0xfffffd806e74a1c8 inode (&ip->i_lock) lock order [1] vmmaplk (&map->lock) -> [2] inode (&ip->i_lock) #0 rw_do_enter_write+0xb7 sys/kern/kern_rwlock.c:233 #1 rrw_enter+0xc6 sys/kern/kern_rwlock.c:616 #2 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 #3 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #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_read+0xa2 sys/kern/sys_generic.c:172 #12 syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] #12 syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 #13 Xsyscall+0x128 lock order [2] inode (&ip->i_lock) -> [1] vmmaplk (&map->lock) #0 rw_do_enter_read+0x9d sys/kern/kern_rwlock.c:352 #1 uvmfault_lookup+0x122 sys/uvm/uvm_fault.c:1864 #2 uvm_fault_check+0x4b sys/uvm/uvm_fault.c:732 #3 uvm_fault+0x106 sys/uvm/uvm_fault.c:668 #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+0xbd4 sys/kern/kern_exec.c:468 #14 start_init+0x3c6 sys/kern/init_main.c:716 #15 proc_trampoline+0x10 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(fffffd806e74a1c8,9,0) at witness_checkorder+0x1047 rw_do_enter_write(fffffd806e74a1b0,1) at rw_do_enter_write+0xb7 sys/kern/kern_rwlock.c:233 rrw_enter(fffffd806e74a1b0,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:616 VOP_LOCK(fffffd806aaaea68,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd806aaaea68,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vn_rdwr(0,fffffd806aaaea68,ffff800011a26080,87,0,1,dc4e6ca40da32d92,0,ffff800000b2a000,0) at vn_rdwr+0xd1 sys/kern/vfs_vnops.c:320 vndstrategy(fffffd806cdb39f0) at vndstrategy+0x4ff sys/dev/vnd.c:342 physio(ffffffff814caab0,2902,8000,ffffffff813cd180,ffff80002a5302d8) at physio+0x2f6 sys/kern/kern_physio.c:162 spec_read(ffff80002a530140) at spec_read+0x155 sys/kern/spec_vnops.c:215 VOP_READ(fffffd806eb0ade0,ffff80002a5302d8,0,fffffd807f7d3618) at VOP_READ+0x102 sys/kern/vfs_vops.c:227 vn_read(fffffd806bfdc7c8,ffff80002a5302d8,0) at vn_read+0x17b sys/kern/vfs_vnops.c:369 dofilereadv(ffff80002a983980,3,ffff80002a5302d8,0,ffff80002a530390) at dofilereadv+0x230 sys/kern/sys_generic.c:252 sys_read(ffff80002a983980,ffff80002a530440,ffff80002a530390) at sys_read+0xa2 sys/kern/sys_generic.c:172 syscall(ffff80002a530440) at syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a530440) at syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x9f837eadb60, count: -16 ddb{0}> show registers rdi 0 rsi 0x80000 acpi_pdirpa+0x6be71 rbp 0xffff80002a52fc20 rbx 0xfffffd800433cc58 rdx 0xffff80000128b600 rcx 0xffff80002a983980 rax 0x7ffff acpi_pdirpa+0x6be70 r8 0xffff80002a52fb00 r9 0x8080808080808080 r10 0x5964e56f0fe2d176 r11 0xe08338ce85fe2b52 r12 0 r13 0xfffffd8003b53f00 r14 0x3 r15 0xffffffff rip 0xffffffff8239cdf5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a52fc10 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=77799 pid=59365 tcnt=2 stat=onproc flags process=0 proc=4000000 runpri=32, usrpri=86, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a982540,0xffff80002a433c00 process=0xffff800039d79498 user=0xffff80002a52b000, vmspace=0xfffffd806bfb4570 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 31579 327946 39539 0 2 0x100002 arp 59365 148640 11193 0 2 0 syz-executor *59365 77799 11193 0 7 0x4000000 syz-executor 39539 333522 73297 0 3 0x10008a sigsusp sh 73297 223103 76768 0 3 0x82 wait syz-executor 66189 59432 76768 0 3 0x82 nanoslp syz-executor 96094 488601 0 0 3 0x14280 nfsidl nfsio 22605 254361 0 0 3 0x14280 nfsidl nfsio 78868 127999 0 0 3 0x14280 nfsidl nfsio 62078 131960 0 0 3 0x14280 nfsidl nfsio 86915 506007 0 0 3 0x14280 nfsidl nfsio 16830 498832 0 0 3 0x14280 nfsidl nfsio 9717 316059 0 0 3 0x14280 nfsidl nfsio 37918 152679 0 0 3 0x14280 nfsidl nfsio 97418 421837 0 0 3 0x14280 nfsidl nfsio 42796 227384 0 0 3 0x14280 nfsidl nfsio 34024 25187 0 0 3 0x14280 nfsidl nfsio 48342 400523 0 0 3 0x14280 nfsidl nfsio 47302 99486 0 0 3 0x14280 nfsidl nfsio 72174 503837 0 0 3 0x14280 nfsidl nfsio 31227 252269 0 0 3 0x14280 nfsidl nfsio 50184 321235 0 0 3 0x14280 nfsidl nfsio 37290 108033 0 0 3 0x14280 nfsidl nfsio 57718 522291 0 0 3 0x14280 nfsidl nfsio 37382 292157 0 0 3 0x14280 nfsidl nfsio 80835 26364 0 0 3 0x14280 nfsidl nfsio 76095 454447 1 0 3 0x3810 suspend syz-executor 76095 338506 1 0 4 0x4081810 syz-executor 65091 193143 76768 0 3 0x82 piperd syz-executor 90198 47414 0 0 3 0x14200 acct acct 56189 89952 0 0 3 0x14200 bored sosplice 896 113286 76768 0 3 0x82 piperd syz-executor 11193 293465 76768 0 3 0x82 nanoslp syz-executor 75438 301455 76768 0 3 0x82 nanoslp syz-executor 5935 418070 76768 0 3 0x82 piperd syz-executor 76768 93110 31473 0 3 0x82 nanoslp syz-executor 31473 476545 66039 0 3 0x10008a sigsusp ksh 66039 219231 20959 0 3 0x98 kqread sshd-session 20959 347568 12558 0 3 0x92 kqread sshd-session 34066 214511 1 0 3 0x100083 ttyin getty 12558 163416 1 0 3 0x88 kqread sshd 98370 193987 35894 74 3 0x1100092 bpf pflogd 35894 259066 1 0 3 0x80 sbwait pflogd 59431 226057 46009 73 3 0x1100090 kqread syslogd 46009 523330 1 0 3 0x100082 sbwait syslogd 85208 489935 1 0 3 0x100080 kqread resolvd 79089 273899 92243 77 3 0x100092 kqread dhcpleased 71230 232221 92243 77 3 0x100092 kqread dhcpleased 92243 194445 1 0 3 0x80 kqread dhcpleased 45565 385520 0 0 3 0x14200 bored smr 90617 2568 0 0 2 0x14200 zerothread 17058 23339 0 0 3 0x14200 aiodoned aiodoned 41119 118330 0 0 3 0x14200 syncer update 63069 225391 0 0 3 0x14200 cleaner cleaner 12158 343892 0 0 7 0x14200 reaper 76691 502785 0 0 3 0x14200 pgdaemon pagedaemon 43369 432547 0 0 3 0x14200 bored viomb 76683 125270 0 0 3 0x40014200 acpi0 acpi0 66284 78488 0 0 3 0x40014200 idle1 86892 462989 0 0 3 0x14200 bored softnet3 67564 146633 0 0 3 0x14200 bored softnet2 77432 9115 0 0 3 0x14200 bored softnet1 2342 328502 0 0 3 0x14200 bored softnet0 50471 70481 0 0 3 0x14200 bored systqmp 94965 318343 0 0 3 0x14200 bored systq 22204 330086 0 0 3 0x14200 tmoslp softclockmp 23968 500069 0 0 3 0x40014200 tmoslp softclock 55162 321110 0 0 3 0x40014200 idle0 1 127943 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 59365 (syz-executor) thread 0xffff80002a983980 (77799) shared rwlock vmmaplk r = 0 (0xfffffd806bfb4670) #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_read+0x3af sys/kern/kern_rwlock.c:405 #2 uvm_vslock_device+0x149 sys/uvm/uvm_glue.c:172 #3 physio+0x277 sys/kern/kern_physio.c:139 #4 spec_read+0x155 sys/kern/spec_vnops.c:215 #5 VOP_READ+0x102 sys/kern/vfs_vops.c:227 #6 vn_read+0x17b sys/kern/vfs_vnops.c:369 #7 dofilereadv+0x230 sys/kern/sys_generic.c:252 #8 sys_read+0xa2 sys/kern/sys_generic.c:172 #9 syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] #9 syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 #10 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff836710f8) #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_read+0xa2 sys/kern/sys_generic.c:172 #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 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10237 11160K 11420K 166960K 12172 0 pcb 17 16K 17K 166960K 219 0 rtable 187 7K 8K 166960K 997 0 pf 36 17K 25K 166960K 110 0 ifaddr 40 7K 7K 166960K 137 0 ifgroup 59 2K 2K 166960K 158 0 sysctl 4 1K 3K 166960K 9 0 counters 66 36K 37K 166960K 120 0 ioctlops 0 0K 4K 166960K 1538 0 iov 0 0K 24K 166960K 113 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1462 92K 92K 166960K 2177 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 3 5K 9K 166960K 13 0 VM map 2 1K 1K 166960K 2 0 sem 19 5K 10K 166960K 38 0 dirhash 12 2K 2K 166960K 33 0 ACPI 1690 195K 286K 166960K 12468 0 file desc 14 49K 93K 166960K 1150 0 sigio 0 0K 0K 166960K 16 0 proc 72 91K 127K 166960K 1119 0 subproc 72 4K 5K 166960K 279 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 223 0 in_multi 76 5K 7K 166960K 319 0 ether_multi 1 0K 0K 166960K 2 0 mrt 0 0K 0K 166960K 3 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 241 1076K 1076K 166960K 241 0 exec 0 0K 1K 166960K 786 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 3 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 189 71K 86K 166960K 11079 0 UVM aobj 26 2K 2K 166960K 28 0 pinsyscall 40 80K 103K 166960K 2756 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 47 0 NDP 13 0K 2K 166960K 94 0 temp 80 6900K 7152K 166960K 38408 0 kqueue 13 20K 28K 166960K 145 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 120 150 0 146 2 1 1 2 0 8 0 rtentry 112 330 0 249 4 0 4 4 0 8 0 unpcb 144 491 0 474 5 1 4 4 0 8 3 syncache 336 13 0 13 3 3 0 1 0 8 0 tcpqe 32 1 0 1 1 1 0 1 0 8 0 tcpcb 808 343 0 338 13 7 6 7 0 8 5 arp 120 59 0 42 1 0 1 1 0 8 0 inpcb 376 1248 0 1239 24 17 7 15 0 8 5 nd6 136 79 0 61 1 0 1 1 0 8 0 pkpcb 40 6 0 6 2 1 1 1 0 8 1 kcovpl 48 31 0 23 1 0 1 1 0 8 0 ppxss 1168 5 0 5 2 2 0 1 0 8 0 pffrag 232 6 0 0 1 0 1 1 0 482 0 pffrnode 88 6 0 0 1 0 1 1 0 8 0 pffrent 40 8 0 2 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 pfanchor 1288 2 0 0 1 0 1 1 0 8 0 pfstitem 24 51 0 22 1 0 1 1 0 8 0 pfstkey 128 51 0 22 2 0 2 2 0 8 0 pfstate 376 51 0 22 5 0 5 5 0 8 0 pfrule 1344 22 0 15 2 0 2 2 0 8 0 art_heap8 4096 3 0 0 3 0 3 3 0 8 0 art_heap4 256 1380 0 1062 30 8 22 29 0 8 1 art_table 32 1383 0 1062 4 0 4 4 0 8 0 art_node 16 325 0 256 1 0 1 1 0 8 0 sysvmsgpl 40 17 0 9 1 0 1 1 0 8 0 semapl 112 30 0 13 1 0 1 1 0 8 0 shmpl 112 25 0 2 1 0 1 1 0 8 0 dirhash 1024 32 0 15 3 0 3 3 0 8 0 dino2pl 256 2960 0 1423 97 0 97 97 0 8 0 ffsino 280 2960 0 1423 111 0 111 111 0 8 0 nchpl 144 4154 0 2408 65 0 65 65 0 8 0 uvmvnodes 80 3615 0 0 74 0 74 74 0 8 0 vnodes 216 3615 0 0 201 0 201 201 0 8 0 namei 1024 15835 0 15835 4 3 1 1 0 8 1 percpumem 16 74 0 27 1 0 1 1 0 8 0 kstatmem 264 80 0 54 3 1 2 3 0 8 0 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 4 0 4 2 2 0 1 0 8 0 scxspl 216 12545 0 12545 12 11 1 8 1 8 1 plimitpl 152 209 0 191 1 0 1 1 0 8 0 sigapl 424 1434 0 1365 11 2 9 9 0 8 0 futexpl 64 10850 0 10850 3 2 1 1 0 8 1 knotepl 120 801 0 0 25 0 25 25 0 8 0 kqueuepl 216 227 0 218 1 0 1 1 0 8 0 pipepl 328 323 0 295 10 2 8 8 0 8 5 fdescpl 504 1393 0 1365 6 1 5 5 0 8 0 filepl 152 7881 0 7668 30 11 19 20 0 8 8 lockfpl 104 266 0 263 1 0 1 1 0 8 0 lockfspl 48 105 0 102 1 0 1 1 0 8 0 sessionpl 144 53 0 44 1 0 1 1 0 8 0 pgrppl 48 86 0 69 1 0 1 1 0 8 0 ucredpl 104 1112 0 1095 1 0 1 1 0 8 0 zombiepl 144 1367 0 1365 1 0 1 1 0 8 0 processpl 1168 1434 0 1365 7 1 6 6 0 8 0 procpl 648 2669 0 2598 10 2 8 8 0 8 0 srpgc 96 12 0 12 3 3 0 1 0 8 0 sosppl 168 2 0 2 1 1 0 1 0 8 0 sockpl 688 1968 0 1938 28 16 12 16 0 8 8 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 6 0 0 1 0 1 1 0 8 0 mcl4k 4096 131 0 0 17 0 17 17 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 25 0 0 4 0 4 4 0 8 0 mtagpl 96 7 0 0 1 0 1 1 0 8 0 mbufpl 256 190 0 0 12 0 12 12 0 8 0 bufpl 280 3966 0 132 274 0 274 274 0 8 0 anonpl 24 166612 0 163283 76 28 48 48 0 185 24 amapchunkpl 152 34342 0 33982 42 13 29 30 0 158 9 amappl16 200 2511 0 2482 37 26 11 15 0 8 8 amappl15 192 1 0 1 1 1 0 1 0 8 0 amappl14 184 163 0 150 1 0 1 1 0 8 0 amappl13 176 22 0 22 1 1 0 1 0 8 0 amappl12 168 2347 0 2319 4 2 2 3 0 8 0 amappl11 160 50 0 36 1 0 1 1 0 8 0 amappl10 152 5 0 3 1 0 1 1 0 8 0 amappl9 144 253 0 253 1 1 0 1 0 8 0 amappl8 136 28 0 25 1 0 1 1 0 8 0 amappl7 128 153 0 140 1 0 1 1 0 8 0 amappl6 120 368 0 364 1 0 1 1 0 8 0 amappl5 112 198 0 188 1 0 1 1 0 8 0 amappl4 104 420 0 401 1 0 1 1 0 8 0 amappl3 96 6793 0 6707 4 0 4 4 0 8 0 amappl2 88 974 0 908 2 0 2 2 0 8 0 amappl1 80 13889 0 13301 14 0 14 14 0 8 0 amappl 88 10489 0 10359 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 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 128 255 0 255 3 3 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 27 0 2 1 0 1 1 0 8 0 uaddrrnd 24 1393 0 1365 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1393 0 1365 1 0 1 1 0 8 0 vmmpekpl 168 13533 0 13470 3 0 3 3 0 8 0 vmmpepl 168 91061 0 89378 112 16 96 96 0 357 11 vmsppl 456 1392 0 1365 6 1 5 5 0 8 0 rwobjpl 64 29794 0 25219 78 1 77 77 0 8 2 pdppl 4096 2793 0 2730 123 50 73 85 0 8 10 pvpl 32 15062 0 0 122 0 122 122 0 265 0 pmappl 248 1392 0 1365 3 0 3 3 0 8 0 extentpl 40 55 0 38 1 0 1 1 0 8 0 phpool 112 330 0 78 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(fffffd806e74a1c8,9,0) at witness_checkorder+0x1047 rw_do_enter_write(fffffd806e74a1b0,1) at rw_do_enter_write+0xb7 sys/kern/kern_rwlock.c:233 rrw_enter(fffffd806e74a1b0,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:616 VOP_LOCK(fffffd806aaaea68,2001) at VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524 vn_lock(fffffd806aaaea68,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:570 vn_rdwr(0,fffffd806aaaea68,ffff800011a26080,87,0,1,dc4e6ca40da32d92,0,ffff800000b2a000,0) at vn_rdwr+0xd1 sys/kern/vfs_vnops.c:320 vndstrategy(fffffd806cdb39f0) at vndstrategy+0x4ff sys/dev/vnd.c:342 physio(ffffffff814caab0,2902,8000,ffffffff813cd180,ffff80002a5302d8) at physio+0x2f6 sys/kern/kern_physio.c:162 spec_read(ffff80002a530140) at spec_read+0x155 sys/kern/spec_vnops.c:215 VOP_READ(fffffd806eb0ade0,ffff80002a5302d8,0,fffffd807f7d3618) at VOP_READ+0x102 sys/kern/vfs_vops.c:227 vn_read(fffffd806bfdc7c8,ffff80002a5302d8,0) at vn_read+0x17b sys/kern/vfs_vnops.c:369 dofilereadv(ffff80002a983980,3,ffff80002a5302d8,0,ffff80002a530390) at dofilereadv+0x230 sys/kern/sys_generic.c:252 sys_read(ffff80002a983980,ffff80002a530440,ffff80002a530390) at sys_read+0xa2 sys/kern/sys_generic.c:172 syscall(ffff80002a530440) at syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a530440) at syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x9f837eadb60, count: -16 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(ffffffff83670ef0) at __mp_lock+0x19e __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff83670ef0) at __mp_lock+0x19e sys/kern/kern_lock.c:144 reaper(ffff8000ffffd6d0) at reaper+0x24b sys/kern/kern_exit.c:478 end trace frame: 0x0, count: -5