panic: kernel diagnostic assertion "len >= 0 && !M_READONLY(m)" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/uipc_mbuf.c", line 1384 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 71056 25816 0 0 0 1 syz-executor.3 * 15586 91686 0 0 0x4000000 0K syz-executor.4 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff82577da7) at panic+0x177 sys/kern/subr_prf.c:202 __assert(ffffffff825ebc34,ffffffff8255f654,568,ffffffff8258dc04) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd8066725500,ffffffd7) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff800027af4ad8,ffff800000c7a600,ffff800027af4838,ffff800027af4738) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(41700,ffff800027af4ad8,1) at bpfwrite+0x169 sys/net/bpf.c:644 spec_write(ffff800027af4930) at spec_write+0xd4 sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd8067db2be8,ffff800027af4ad8,1,fffffd807f7d8600) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd806842ebe8,ffff800027af4ad8,0) at vn_write+0x157 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000ffff5ce0,3,ffff800027af4ad8,0,ffff800027af4bd0) at dofilewritev+0x19c sys/kern/sys_generic.c:381 sys_write(ffff8000ffff5ce0,ffff800027af4b78,ffff800027af4bd0) at sys_write+0x83 sys/kern/sys_generic.c:301 syscall(ffff800027af4c40) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800027af4c40) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xf8ac4c9ea00, count: 2 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic *cpu0: kernel diagnostic assertion "len >= 0 && !M_READONLY(m)" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/uipc_mbuf.c", line 1384 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff82577da7) at panic+0x177 sys/kern/subr_prf.c:202 __assert(ffffffff825ebc34,ffffffff8255f654,568,ffffffff8258dc04) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd8066725500,ffffffd7) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff800027af4ad8,ffff800000c7a600,ffff800027af4838,ffff800027af4738) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(41700,ffff800027af4ad8,1) at bpfwrite+0x169 sys/net/bpf.c:644 spec_write(ffff800027af4930) at spec_write+0xd4 sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd8067db2be8,ffff800027af4ad8,1,fffffd807f7d8600) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd806842ebe8,ffff800027af4ad8,0) at vn_write+0x157 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000ffff5ce0,3,ffff800027af4ad8,0,ffff800027af4bd0) at dofilewritev+0x19c sys/kern/sys_generic.c:381 sys_write(ffff8000ffff5ce0,ffff800027af4b78,ffff800027af4bd0) at sys_write+0x83 sys/kern/sys_generic.c:301 syscall(ffff800027af4c40) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800027af4c40) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xf8ac4c9ea00, count: -13 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800027af4550 rbx 0xffffffff82966bff cpu_info_full_primary+0x2bff rdx 0 rcx 0 rax 0xffff8000ffff5ce0 r8 0 r9 0x8080808080808080 r10 0x751e71465f698613 r11 0x73153fac874aaae1 r12 0xffffffff82966a00 cpu_info_full_primary+0x2a00 r13 0 r14 0 r15 0x1 rip 0xffffffff8228cc28 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800027af4540 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.4) pid=15586 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff4d20,0xffff8000ffff5a50 process=0xffff80002e3d4448 user=0xffff800027aef000, vmspace=0xfffffd8066e3d2f8 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 96235 464563 11617 0 2 0 syz-executor.1 25816 71056 70460 0 7 0 syz-executor.3 92481 154370 98922 0 3 0x80 nanoslp syz-executor.7 92481 342256 98922 0 3 0x4000080 fsleep syz-executor.7 92481 92420 98922 0 3 0x4000080 fsleep syz-executor.7 8860 155655 45030 0 2 0 syz-executor.6 8860 111336 45030 0 3 0x4000080 fsleep syz-executor.6 73164 289371 58522 0 2 0 syz-executor.0 19398 70900 17511 0 2 0 syz-executor.5 19398 292818 17511 0 3 0x4000080 fsleep syz-executor.5 91686 51445 4687 0 2 0 syz-executor.4 *91686 15586 4687 0 7 0x4000000 syz-executor.4 91686 520802 4687 0 3 0x4000080 fsleep syz-executor.4 91686 508272 4687 0 3 0x4000080 fsleep syz-executor.4 45030 287778 79408 0 2 0x482 syz-executor.6 11617 464279 79408 0 2 0x482 syz-executor.1 22941 164670 0 0 3 0x14280 nfsidl nfsio 28228 21075 0 0 3 0x14280 nfsidl nfsio 70590 445112 0 0 3 0x14280 nfsidl nfsio 37473 181174 0 0 3 0x14280 nfsidl nfsio 5658 106108 0 0 3 0x14280 nfsidl nfsio 72855 116636 0 0 3 0x14280 nfsidl nfsio 67809 238900 0 0 3 0x14280 nfsidl nfsio 24875 18762 0 0 3 0x14280 nfsidl nfsio 45336 453701 0 0 3 0x14280 nfsidl nfsio 48894 229477 0 0 3 0x14280 nfsidl nfsio 40113 500975 0 0 3 0x14280 nfsidl nfsio 92281 393699 0 0 3 0x14280 nfsidl nfsio 50693 499697 0 0 3 0x14280 nfsidl nfsio 3989 452011 0 0 3 0x14280 nfsidl nfsio 65788 114731 0 0 3 0x14280 nfsidl nfsio 67420 222621 0 0 3 0x14280 nfsidl nfsio 78240 359276 0 0 3 0x14280 nfsidl nfsio 17483 456697 0 0 3 0x14280 nfsidl nfsio 54197 353495 0 0 3 0x14280 nfsidl nfsio 36383 455173 0 0 3 0x14280 nfsidl nfsio 98922 154030 79408 0 3 0x82 nanoslp syz-executor.7 4687 109637 79408 0 2 0x482 syz-executor.4 17511 370709 79408 0 2 0x482 syz-executor.5 16768 236816 79408 0 3 0x82 nanoslp syz-executor.2 70460 420714 79408 0 3 0x82 nanoslp syz-executor.3 58522 326869 79408 0 2 0x482 syz-executor.0 79408 41608 48073 0 3 0x82 thrsleep syz-fuzzer 79408 442696 48073 0 2 0x4000482 syz-fuzzer 79408 50290 48073 0 3 0x4000082 kqread syz-fuzzer 79408 203640 48073 0 3 0x4000082 thrsleep syz-fuzzer 79408 485370 48073 0 3 0x4000082 thrsleep syz-fuzzer 79408 302662 48073 0 3 0x4000082 thrsleep syz-fuzzer 79408 24355 48073 0 3 0x4000082 thrsleep syz-fuzzer 79408 153690 48073 0 3 0x4000082 thrsleep syz-fuzzer 79408 245757 48073 0 3 0x4000082 thrsleep syz-fuzzer 48073 401179 45245 0 3 0x10008a sigsusp ksh 45245 290896 92109 0 3 0x9a kqread sshd 81402 128503 1 0 3 0x100083 ttyin getty 92109 103062 1 0 3 0x88 kqread sshd 23922 101953 36767 74 3 0x100092 bpf pflogd 36767 379062 1 0 3 0x80 netio pflogd 89492 151900 11683 73 3 0x100090 kqread syslogd 11683 299493 1 0 3 0x100082 netio syslogd 74811 157554 1 0 3 0x100080 kqread resolvd 46336 303037 99327 77 3 0x100092 kqread dhcpleased 40763 51302 99327 77 3 0x100092 kqread dhcpleased 99327 132346 1 0 3 0x80 kqread dhcpleased 5911 4122 0 0 3 0x14200 bored smr 51632 196420 0 0 2 0x14200 zerothread 81366 241034 0 0 3 0x14200 aiodoned aiodoned 40696 411891 0 0 3 0x14200 syncer update 31808 495597 0 0 3 0x14200 cleaner cleaner 55456 327779 0 0 3 0x14200 reaper reaper 42206 99508 0 0 3 0x14200 pgdaemon pagedaemon 31813 376581 0 0 3 0x14200 bored viomb 28903 258373 0 0 3 0x40014200 acpi0 acpi0 38975 296822 0 0 3 0x40014200 idle1 74848 323361 0 0 3 0x14200 bored softnet 76953 379439 0 0 3 0x14200 bored systqmp 19396 155211 0 0 3 0x14200 bored systq 36994 335539 0 0 2 0x40014200 softclock 85546 376615 0 0 3 0x40014200 idle0 1 46701 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 91686 (syz-executor.4) thread 0xffff8000ffff5ce0 (15586) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82a7ab80) #0 witness_lock+0x44d #1 vn_write+0x42 sys/kern/vfs_vnops.c:399 #2 dofilewritev+0x19c sys/kern/sys_generic.c:381 #3 sys_write+0x83 sys/kern/sys_generic.c:301 #4 syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] #4 syscall+0x489 sys/arch/amd64/amd64/trap.c:585 #5 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10239 7069K 7466K 78643K 17430 0 pcb 13 14K 16K 78643K 246 0 rtable 207 15K 20K 78643K 599 0 ifaddr 90 18K 20K 78643K 211 0 sysctl 2 0K 0K 78643K 2 0 counters 56 35K 35K 78643K 70 0 ioctlops 0 0K 4K 78643K 1889 0 iov 0 0K 16K 78643K 20 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 5 0 vnodes 1407 88K 88K 78643K 2586 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 8 0 VM map 2 1K 1K 78643K 2 0 sem 12 1K 1K 78643K 120 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 17 61K 85K 78643K 1236 0 sigio 0 0K 0K 78643K 5 0 proc 69 87K 111K 78643K 610 0 subproc 104 6K 6K 78643K 130 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 35 0 in_multi 84 5K 6K 78643K 149 0 ether_multi 1 0K 0K 78643K 9 0 mrt 0 0K 0K 78643K 15 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 163 731K 731K 78643K 163 0 exec 0 0K 2K 78643K 783 0 tdb 3 0K 0K 78643K 3 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 359 168K 169K 78643K 17483 0 UVM aobj 42 2K 2K 78643K 42 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 55 0 NDP 13 0K 1K 78643K 42 0 temp 103 4697K 4773K 78643K 25811 0 kqueue 12 18K 24K 78643K 83 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 22 0 0 1 0 1 1 0 8 0 rtpcb 120 72 0 69 1 0 1 1 0 8 0 rtentry 112 152 0 63 4 0 4 4 0 8 0 unpcb 136 1073 0 1058 15 5 10 10 0 8 9 syncache 296 9 0 9 4 4 0 1 0 8 0 tcpqe 32 151 0 151 3 3 0 1 0 8 0 tcpcb 736 260 0 252 8 6 2 5 0 8 0 arp 120 22 0 6 1 0 1 1 0 8 0 inpcb 304 1071 0 1060 15 11 4 9 0 8 3 rttmr 72 6 0 6 2 2 0 1 0 8 0 nd6 48 36 0 16 1 0 1 1 0 8 0 pkpcb 40 6 0 6 1 1 0 1 0 8 0 kcovpl 48 10 0 2 1 0 1 1 0 8 0 pfstscr 40 11 0 11 2 2 0 1 0 8 0 pffrag 232 8 0 7 1 0 1 1 0 482 0 pffrnode 88 8 0 7 1 0 1 1 0 8 0 pffrent 40 148 0 147 1 0 1 1 0 8 0 pfosfp 40 1431 0 1006 5 0 5 5 0 8 0 pfosfpen 112 1431 0 714 21 0 21 21 0 8 0 pfrktable 1344 59 0 57 2 1 1 1 0 8 0 pftag 88 8 0 8 1 1 0 1 0 8 0 pfstitem 24 17 0 11 1 0 1 1 0 8 0 pfstkey 112 39 0 33 1 0 1 1 0 8 0 pfstate 320 28 0 22 2 1 1 2 0 8 0 pfrule 1360 129 0 115 2 0 2 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 651 0 264 31 5 26 31 0 8 0 art_table 32 652 0 264 4 0 4 4 0 8 0 art_node 16 151 0 72 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 110 0 100 1 0 1 1 0 8 0 shmpl 112 39 0 0 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 3002 0 1553 91 0 91 91 0 8 0 ffsino 272 3002 0 1553 97 0 97 97 0 8 0 nchpl 144 4761 0 3128 63 0 63 63 0 8 0 uvmvnodes 80 4202 0 0 86 0 86 86 0 8 0 vnodes 224 4202 0 0 248 0 248 248 0 8 0 namei 1024 17667 0 17667 2 1 1 2 0 8 1 percpumem 16 47 0 7 1 0 1 1 0 8 0 vcpupl 2048 5 0 0 1 0 1 1 0 8 0 vmpool 560 5 0 0 1 0 1 1 0 8 0 pfiaddrpl 120 18 0 14 2 1 1 1 0 8 0 scxspl 216 13874 0 13874 9 8 1 7 0 8 1 plimitpl 152 189 0 173 1 0 1 1 0 8 0 sigapl 424 1557 0 1493 8 0 8 8 0 8 0 futexpl 64 10851 0 10845 1 0 1 1 0 8 0 knotepl 120 104 0 0 4 0 4 4 0 8 0 kqueuepl 216 281 0 273 9 8 1 5 0 8 0 pipepl 336 404 0 376 12 5 7 8 0 8 4 fdescpl 496 1523 0 1493 5 1 4 5 0 8 0 filepl 152 10550 0 10282 34 15 19 22 0 8 8 lockfpl 104 223 0 221 1 0 1 1 0 8 0 lockfspl 48 80 0 78 1 0 1 1 0 8 0 sessionpl 144 26 0 9 1 0 1 1 0 8 0 pgrppl 48 64 0 47 1 0 1 1 0 8 0 ucredpl 96 1322 0 1308 1 0 1 1 0 8 0 zombiepl 144 1493 0 1492 1 0 1 1 0 8 0 processpl 1064 1557 0 1492 5 0 5 5 0 8 0 procpl 672 3828 0 3748 8 0 8 8 0 8 0 srpgc 96 2 0 2 1 1 0 1 0 8 0 sockpl 480 2222 0 2193 60 25 35 35 0 8 31 mcl64k 65536 12 0 0 2 0 2 2 0 8 0 mcl16k 16384 6 0 0 1 0 1 1 0 8 0 mcl12k 12288 12 0 0 2 0 2 2 0 8 0 mcl9k 9216 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 14 0 0 2 0 2 2 0 8 0 mcl4k 4096 12 0 0 2 0 2 2 0 8 0 mcl2k2 2112 7 0 0 1 0 1 1 0 8 0 mcl2k 2048 190 0 0 23 0 23 23 0 8 0 mtagpl 96 1139 0 0 28 0 28 28 0 8 0 mbufpl 256 1415 0 0 87 0 87 87 0 8 0 bufpl 288 5386 0 150 374 0 374 374 0 8 0 anonpl 24 378637 0 358956 138 13 125 127 0 186 0 amapchunkpl 152 41801 0 40905 45 6 39 42 0 158 1 amappl16 200 3272 0 2690 35 4 31 34 0 8 0 amappl15 192 166 0 159 1 0 1 1 0 8 0 amappl14 184 47 0 44 1 0 1 1 0 8 0 amappl13 176 246 0 242 1 0 1 1 0 8 0 amappl12 168 291 0 286 1 0 1 1 0 8 0 amappl11 160 318 0 301 1 0 1 1 0 8 0 amappl10 152 32 0 28 1 0 1 1 0 8 0 amappl9 144 732 0 725 1 0 1 1 0 8 0 amappl8 136 767 0 704 3 0 3 3 0 8 0 amappl7 128 227 0 214 1 0 1 1 0 8 0 amappl6 120 473 0 450 2 0 2 2 0 8 0 amappl5 112 872 0 856 1 0 1 1 0 8 0 amappl4 104 1359 0 1327 2 0 2 2 0 8 0 amappl3 96 666 0 649 1 0 1 1 0 8 0 amappl2 88 894 0 843 3 1 2 3 0 8 0 amappl1 80 30582 0 29999 19 5 14 19 0 8 0 amappl 88 16944 0 16685 7 0 7 7 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 18 0 17 1 0 1 1 0 8 0 aobjpl 72 41 0 0 1 0 1 1 0 8 0 uaddrrnd 24 1528 0 1493 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1528 0 1493 1 0 1 1 0 8 0 vmmpekpl 168 17065 0 17006 3 0 3 3 0 8 0 vmmpepl 168 141754 0 139163 140 19 121 133 0 357 2 vmsppl 368 1527 0 1493 4 0 4 4 0 8 0 rwobjpl 56 39154 0 33331 85 2 83 83 0 8 0 pdppl 4096 3063 0 2991 152 78 74 79 0 8 2 pvpl 32 761856 0 737752 263 50 213 263 0 265 11 pmappl 248 1527 0 1493 3 0 3 3 0 8 0 extentpl 40 58 0 38 1 0 1 1 0 8 0 phpool 112 898 0 97 23 0 23 23 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff82577da7) at panic+0x177 sys/kern/subr_prf.c:202 __assert(ffffffff825ebc34,ffffffff8255f654,568,ffffffff8258dc04) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd8066725500,ffffffd7) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff800027af4ad8,ffff800000c7a600,ffff800027af4838,ffff800027af4738) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(41700,ffff800027af4ad8,1) at bpfwrite+0x169 sys/net/bpf.c:644 spec_write(ffff800027af4930) at spec_write+0xd4 sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd8067db2be8,ffff800027af4ad8,1,fffffd807f7d8600) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd806842ebe8,ffff800027af4ad8,0) at vn_write+0x157 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000ffff5ce0,3,ffff800027af4ad8,0,ffff800027af4bd0) at dofilewritev+0x19c sys/kern/sys_generic.c:381 sys_write(ffff8000ffff5ce0,ffff800027af4b78,ffff800027af4bd0) at sys_write+0x83 sys/kern/sys_generic.c:301 syscall(ffff800027af4c40) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800027af4c40) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xf8ac4c9ea00, count: -13 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020ce8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff82a7a978) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82a7a978) at __mp_lock+0x122 sys/kern/kern_lock.c:147 syscall(ffff80002e401310) at syscall+0x33d mi_syscall sys/sys/syscall_mi.h:74 [inline] syscall(ffff80002e401310) at syscall+0x33d sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff4f00, count: 9 ddb{1}> trace x86_ipi_db(ffff800020ce8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff82a7a978) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82a7a978) at __mp_lock+0x122 sys/kern/kern_lock.c:147 syscall(ffff80002e401310) at syscall+0x33d mi_syscall sys/sys/syscall_mi.h:74 [inline] syscall(ffff80002e401310) at syscall+0x33d sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff4f00, count: -6