kern.securelevel: 0 -> 1 creating runtime link editor directory cache. preserving editor files. starting network daemons: sshd. starting local daemons:. Tue Mar 22 10:55:52 PDT 2022 OpenBSD/amd64 (ci-openbsd-multicore-8.c.syzkaller.internal) (tty00) Warning: Permanently added '10.128.10.59' (ED25519) to the list of known hosts. executing program login: panic: acquiring blockable sleep lock with spinlock or critical section held (kernel_lock) &kernel_lock Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *165426 30709 0 0 0 0 syz-executor1476446240 516859 70260 0 0 0 1 syz-executor1476446240 db_enter() at db_enter+0x18 panic(ffffffff825a2db5) at panic+0x177 witness_checkorder(ffffffff829f3ad8,9,0) at witness_checkorder+0x116d __mp_lock(ffffffff829f38d0) at __mp_lock+0xa1 selwakeup(fffffd807f5474f0) at selwakeup+0x16 sorwakeup(fffffd807f5473d8) at sorwakeup+0xc9 rip_input(ffff80002120fef8,ffff80002120ff04,0,2) at rip_input+0x3b0 ip_deliver(ffff80002120fef8,ffff80002120ff04,0,2) at ip_deliver+0x322 ip_ours(ffff80002120fef8,ffff80002120ff04,fffffd806d2926bc,0) at ip_ours+0x3ba ip_input_if(ffff80002120fef8,ffff80002120ff04,4,0,ffff800000689000) at ip_input_if+0x2a1 ipv4_input(ffff800000689000,fffffd806d292600) at ipv4_input+0x48 if_input_local(ffff800000689000,fffffd806d292600,2) at if_input_local+0x10e ip_output(fffffd806d292a00,0,fffffd806f687420,20,0,fffffd806f6873a8,46b983d8eac4981a) at ip_output+0xb05 rip_output(fffffd806d292a00,fffffd807f547978,ffff800021210150,1) at rip_output+0x2cb end trace frame: 0xffff8000212101d0, count: 0 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: acquiring blockable sleep lock with spinlock or critical section held (kernel_lock) &kernel_lock ddb{0}> trace db_enter() at db_enter+0x18 panic(ffffffff825a2db5) at panic+0x177 witness_checkorder(ffffffff829f3ad8,9,0) at witness_checkorder+0x116d __mp_lock(ffffffff829f38d0) at __mp_lock+0xa1 selwakeup(fffffd807f5474f0) at selwakeup+0x16 sorwakeup(fffffd807f5473d8) at sorwakeup+0xc9 rip_input(ffff80002120fef8,ffff80002120ff04,0,2) at rip_input+0x3b0 ip_deliver(ffff80002120fef8,ffff80002120ff04,0,2) at ip_deliver+0x322 ip_ours(ffff80002120fef8,ffff80002120ff04,fffffd806d2926bc,0) at ip_ours+0x3ba ip_input_if(ffff80002120fef8,ffff80002120ff04,4,0,ffff800000689000) at ip_input_if+0x2a1 ipv4_input(ffff800000689000,fffffd806d292600) at ipv4_input+0x48 if_input_local(ffff800000689000,fffffd806d292600,2) at if_input_local+0x10e ip_output(fffffd806d292a00,0,fffffd806f687420,20,0,fffffd806f6873a8,46b983d8eac4981a) at ip_output+0xb05 rip_output(fffffd806d292a00,fffffd807f547978,ffff800021210150,1) at rip_output+0x2cb rip_usrreq(fffffd807f547978,9,fffffd806d292a00,0,0,ffff80002119ed20) at rip_usrreq+0x49c sosend(fffffd807f547978,0,ffff8000212103e0,0,0,0) at sosend+0x632 dofilewritev(ffff80002119ed20,3,ffff8000212103e0,0,ffff8000212104e0) at dofilewritev+0x19c sys_writev(ffff80002119ed20,ffff800021210488,ffff8000212104e0) at sys_writev+0xa7 syscall(ffff800021210550) at syscall+0x489 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4c80, count: -20 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80002120fa80 rbx 0xffffffff8298dbff cpu_info_full_primary+0x2bff rdx 0x3fd rcx 0 rax 0x68 r8 0x101010101010101 r9 0x8080808080808080 r10 0x66d36eb50989c84f r11 0x80c3ad1c49cfcd3d r12 0xffffffff8298da00 cpu_info_full_primary+0x2a00 r13 0 r14 0 r15 0x1 rip 0xffffffff811e4c58 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002120fa70 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor1476446240) pid=165426 stat=onproc flags process=0 proc=0 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80002119f500,0xffff80002119efd0 process=0xffff8000ffffa998 user=0xffff80002120b000, vmspace=0xfffffd806cc0e5d0 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 24913 196049 70260 0 2 0 syz-executor1476446240 94350 451574 95346 0 2 0 syz-executor1476446240 *30709 165426 39723 0 7 0 syz-executor1476446240 96279 507 89009 0 2 0 syz-executor1476446240 91902 132793 97861 0 3 0 biowait syz-executor1476446240 80289 16918 97861 0 3 0 biowait syz-executor1476446240 95346 305639 97861 0 3 0x80 nanoslp syz-executor1476446240 89009 91194 97861 0 3 0x80 nanoslp syz-executor1476446240 39723 133206 97861 0 3 0x80 nanoslp syz-executor1476446240 14233 103357 97861 0 3 0 biowait syz-executor1476446240 41614 174 97861 0 3 0 biowait syz-executor1476446240 70260 516859 97861 0 7 0 syz-executor1476446240 97861 293920 2990 0 3 0x82 nanoslp syz-executor1476446240 2990 431273 88953 0 3 0x10008a sigsusp ksh 88953 480109 50642 0 2 0x12 sshd 78913 428607 1 0 3 0x100083 ttyin getty 50642 378402 1 0 3 0x88 kqread sshd 16928 199573 62992 74 3 0x1100092 bpf pflogd 62992 405173 1 0 3 0x80 netio pflogd 80236 178160 57747 73 3 0x1100090 kqread syslogd 57747 187692 1 0 3 0x100082 netio syslogd 19598 386295 1 0 3 0x100080 kqread resolvd 72408 290208 97513 77 3 0x100092 kqread dhcpleased 87904 457670 97513 77 3 0x100092 kqread dhcpleased 97513 316175 1 0 3 0x80 kqread dhcpleased 27711 309851 0 0 3 0x14200 bored smr 4608 251054 0 0 2 0x14200 zerothread 72731 13509 0 0 3 0x14200 aiodoned aiodoned 2608 509137 0 0 3 0x14200 syncer update 50105 451851 0 0 3 0x14200 cleaner cleaner 98319 495471 0 0 3 0x14200 reaper reaper 10222 13113 0 0 3 0x14200 pgdaemon pagedaemon 54125 87219 0 0 3 0x14200 bored viomb 48831 340993 0 0 3 0x40014200 acpi0 acpi0 64245 204713 0 0 3 0x40014200 idle1 98731 267150 0 0 3 0x14200 bored softnet 78123 220788 0 0 3 0x14200 bored systqmp 42388 16751 0 0 3 0x14200 bored systq 65358 81752 0 0 3 0x40014200 bored softclock 26152 263897 0 0 3 0x40014200 idle0 1 202524 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 0: exclusive mutex &table->inpt_mtx r = 0 (0xffffffff82b03010) #0 witness_lock+0x44d #1 mtx_enter_try+0x100 #2 mtx_enter+0x4b #3 rip_input+0x135 #4 ip_deliver+0x322 #5 ip_ours+0x3ba #6 ip_input_if+0x2a1 #7 ipv4_input+0x48 #8 if_input_local+0x10e #9 ip_output+0xb05 #10 rip_output+0x2cb #11 rip_usrreq+0x49c #12 sosend+0x632 #13 dofilewritev+0x19c #14 sys_writev+0xa7 #15 syscall+0x489 #16 Xsyscall+0x128 Process 30709 (syz-executor1476446240) thread 0xffff80002119ed20 (165426) exclusive rwlock netlock r = 0 (0xffffffff82904160) #0 witness_lock+0x44d #1 solock+0x86 #2 sosend+0x517 #3 dofilewritev+0x19c #4 sys_writev+0xa7 #5 syscall+0x489 #6 Xsyscall+0x128 exclusive mutex &table->inpt_mtx r = 0 (0xffffffff82b03010) #0 witness_lock+0x44d #1 mtx_enter_try+0x100 #2 mtx_enter+0x4b #3 rip_input+0x135 #4 ip_deliver+0x322 #5 ip_ours+0x3ba #6 ip_input_if+0x2a1 #7 ipv4_input+0x48 #8 if_input_local+0x10e #9 ip_output+0xb05 #10 rip_output+0x2cb #11 rip_usrreq+0x49c #12 sosend+0x632 #13 dofilewritev+0x19c #14 sys_writev+0xa7 #15 syscall+0x489 #16 Xsyscall+0x128 Process 91902 (syz-executor1476446240) thread 0xffff80002119fce0 (132793) exclusive rrwlock inode r = 0 (0xfffffd806cc2c3c8) #0 witness_lock+0x44d #1 rw_enter+0x3e1 #2 rrw_enter+0x8b #3 VOP_LOCK+0x87 #4 ufs_ihashins+0x42 #5 ffs_vget+0x141 #6 ffs_inode_alloc+0x1be #7 ufs_mkdir+0xf4 #8 VOP_MKDIR+0xbf #9 domkdirat+0x121 #10 syscall+0x489 #11 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806d4111b8) #0 witness_lock+0x44d #1 rw_enter+0x3e1 #2 rrw_enter+0x8b #3 VOP_LOCK+0x87 #4 vn_lock+0x84 #5 vfs_lookup+0xd1 #6 namei+0x36a #7 domkdirat+0x75 #8 syscall+0x489 #9 Xsyscall+0x128 Process 80289 (syz-executor1476446240) thread 0xffff800021143268 (16918) exclusive rrwlock inode r = 0 (0xfffffd806cc2c6f8) #0 witness_lock+0x44d #1 rw_enter+0x3e1 #2 rrw_enter+0x8b #3 VOP_LOCK+0x87 #4 ufs_ihashins+0x42 #5 ffs_vget+0x141 #6 ffs_inode_alloc+0x1be #7 ufs_mkdir+0xf4 #8 VOP_MKDIR+0xbf #9 domkdirat+0x121 #10 syscall+0x489 #11 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806d4115f8) #0 witness_lock+0x44d #1 rw_enter+0x3e1 #2 rrw_enter+0x8b #3 VOP_LOCK+0x87 #4 vn_lock+0x84 #5 vfs_lookup+0xd1 #6 namei+0x36a #7 domkdirat+0x75 #8 syscall+0x489 #9 Xsyscall+0x128 Process 14233 (syz-executor1476446240) thread 0xffff800021142548 (103357) exclusive rrwlock inode r = 0 (0xfffffd806cc2cd58) #0 witness_lock+0x44d #1 rw_enter+0x3e1 #2 rrw_enter+0x8b #3 VOP_LOCK+0x87 #4 ufs_ihashins+0x42 #5 ffs_vget+0x141 #6 ffs_inode_alloc+0x1be #7 ufs_mkdir+0xf4 #8 VOP_MKDIR+0xbf #9 domkdirat+0x121 #10 syscall+0x489 #11 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806d4110a8) #0 witness_lock+0x44d #1 rw_enter+0x3e1 #2 rrw_enter+0x8b #3 VOP_LOCK+0x87 #4 vn_lock+0x84 #5 vfs_lookup+0xd1 #6 namei+0x36a #7 domkdirat+0x75 #8 syscall+0x489 #9 Xsyscall+0x128 Process 41614 (syz-executor1476446240) thread 0xffff8000ffff7cf0 (174) exclusive rrwlock inode r = 0 (0xfffffd806d411e78) #0 witness_lock+0x44d #1 rw_enter+0x3e1 #2 rrw_enter+0x8b #3 VOP_LOCK+0x87 #4 ufs_ihashins+0x42 #5 ffs_vget+0x141 #6 ffs_inode_alloc+0x1be #7 ufs_mkdir+0xf4 #8 VOP_MKDIR+0xbf #9 domkdirat+0x121 #10 syscall+0x489 #11 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806d4113d8) #0 witness_lock+0x44d #1 rw_enter+0x3e1 #2 rrw_enter+0x8b #3 VOP_LOCK+0x87 #4 vn_lock+0x84 #5 vfs_lookup+0xd1 #6 namei+0x36a #7 domkdirat+0x75 #8 syscall+0x489 #9 Xsyscall+0x128 Process 70260 (syz-executor1476446240) thread 0xffff8000ffff67f0 (516859) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff829f3ad8) #0 witness_lock+0x44d #1 syscall+0x3ef #2 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10149 6454K 6455K 78643K 11239 0 pcb 13 8K 8K 78643K 17 0 rtable 62 2K 2K 78643K 112 0 ifaddr 29 8K 8K 78643K 32 0 counters 40 33K 33K 78643K 40 0 ioctlops 0 0K 4K 78643K 1479 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 5 0 vnodes 1167 73K 73K 78643K 1180 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 1K 78643K 2 0 VM map 2 1K 1K 78643K 2 0 sem 2 0K 0K 78643K 2 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 1 0K 0K 78643K 1 0 proc 67 87K 87K 78643K 282 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 11 0K 0K 78643K 11 0 ether_multi 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 25 122K 122K 78643K 25 0 exec 0 0K 2K 78643K 432 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 102 5K 5K 78643K 2203 0 UVM aobj 3 2K 2K 78643K 3 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 4 0K 0K 78643K 4 0 temp 24 4694K 4757K 78643K 3175 0 kqueue 11 16K 18K 78643K 24 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 17 0 14 1 0 1 1 0 8 0 rtentry 112 23 0 1 1 0 1 1 0 8 0 unpcb 136 35 0 20 1 0 1 1 0 8 0 syncache 296 5 0 5 1 0 1 1 0 8 1 tcpqe 32 13 0 13 1 1 0 1 0 8 0 tcpcb 736 8 0 5 1 0 1 1 0 8 0 arp 120 2 0 0 1 0 1 1 0 8 0 inpcb 312 35 0 26 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 8 0 0 1 0 1 1 0 8 0 pfstkey 112 8 0 0 1 0 1 1 0 8 0 pfstate 320 8 0 0 1 0 1 1 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 97 0 0 7 0 7 7 0 8 0 art_table 32 98 0 0 1 0 1 1 0 8 0 art_node 16 22 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1440 0 39 88 0 88 88 0 8 0 ffsino 272 1440 0 39 94 0 94 94 0 8 0 nchpl 144 1618 0 49 59 0 59 59 0 8 0 uvmvnodes 80 1450 0 0 30 0 30 30 0 8 0 vnodes 224 1450 0 0 86 0 86 86 0 8 0 namei 1024 4457 0 4453 2 0 2 2 0 8 0 percpumem 16 32 0 0 1 0 1 1 0 8 0 scxspl 216 3888 0 3884 2 0 2 2 0 8 1 plimitpl 152 16 0 9 1 0 1 1 0 8 0 sigapl 424 332 0 291 5 0 5 5 0 8 0 knotepl 120 47 0 0 2 0 2 2 0 8 0 kqueuepl 216 20 0 13 1 0 1 1 0 8 0 pipepl 336 86 0 83 1 0 1 1 0 8 0 fdescpl 496 318 0 291 4 0 4 4 0 8 0 filepl 152 1148 0 1087 3 0 3 3 0 8 0 lockfpl 104 6 0 4 1 0 1 1 0 8 0 lockfspl 48 4 0 2 1 0 1 1 0 8 0 sessionpl 144 18 0 9 1 0 1 1 0 8 0 pgrppl 48 18 0 9 1 0 1 1 0 8 0 ucredpl 96 69 0 57 1 0 1 1 0 8 0 zombiepl 144 291 0 291 1 0 1 1 0 8 1 processpl 1064 332 0 291 3 0 3 3 0 8 0 procpl 672 332 0 291 4 0 4 4 0 8 0 sockpl 480 87 0 60 4 0 4 4 0 8 0 mcl8k 8192 5 0 0 1 0 1 1 0 8 0 mcl4k 4096 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 81 0 0 11 0 11 11 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 130 0 0 9 0 9 9 0 8 0 bufpl 288 2034 0 93 139 0 139 139 0 8 0 anonpl 24 41514 0 38951 19 2 17 17 0 186 1 amapchunkpl 152 4017 0 3844 8 1 7 7 0 158 0 amappl16 200 29 0 29 1 1 0 1 0 8 0 amappl15 192 67 0 64 1 0 1 1 0 8 0 amappl13 176 34 0 33 1 0 1 1 0 8 0 amappl12 168 11 0 11 1 0 1 1 0 8 1 amappl11 160 48 0 33 1 0 1 1 0 8 0 amappl10 152 4 0 1 1 0 1 1 0 8 0 amappl9 144 454 0 452 1 0 1 1 0 8 0 amappl8 136 370 0 367 1 0 1 1 0 8 0 amappl7 128 66 0 63 1 0 1 1 0 8 0 amappl6 120 127 0 101 1 0 1 1 0 8 0 amappl5 112 180 0 168 1 0 1 1 0 8 0 amappl4 104 638 0 616 1 0 1 1 0 8 0 amappl3 96 121 0 112 1 0 1 1 0 8 0 amappl2 88 370 0 332 1 0 1 1 0 8 0 amappl1 80 8795 0 8361 9 0 9 9 0 8 0 amappl 88 1921 0 1838 2 0 2 2 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 2 0 0 1 0 1 1 0 8 0 uaddrrnd 24 318 0 291 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 318 0 291 1 0 1 1 0 8 0 vmmpekpl 168 6234 0 6219 1 0 1 1 0 8 0 vmmpepl 168 26718 0 25653 47 0 47 47 0 357 0 vmsppl 368 317 0 291 3 0 3 3 0 8 0 rwobjpl 56 9557 0 7522 29 0 29 29 0 8 0 pdppl 4096 643 0 582 73 12 61 61 0 8 0 pvpl 32 135126 0 130420 40 1 39 39 0 265 1 pmappl 248 317 0 291 2 0 2 2 0 8 0 extentpl 40 58 0 38 1 0 1 1 0 8 0 phpool 112 440 0 15 13 0 13 13 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 panic(ffffffff825a2db5) at panic+0x177 witness_checkorder(ffffffff829f3ad8,9,0) at witness_checkorder+0x116d __mp_lock(ffffffff829f38d0) at __mp_lock+0xa1 selwakeup(fffffd807f5474f0) at selwakeup+0x16 sorwakeup(fffffd807f5473d8) at sorwakeup+0xc9 rip_input(ffff80002120fef8,ffff80002120ff04,0,2) at rip_input+0x3b0 ip_deliver(ffff80002120fef8,ffff80002120ff04,0,2) at ip_deliver+0x322 ip_ours(ffff80002120fef8,ffff80002120ff04,fffffd806d2926bc,0) at ip_ours+0x3ba ip_input_if(ffff80002120fef8,ffff80002120ff04,4,0,ffff800000689000) at ip_input_if+0x2a1 ipv4_input(ffff800000689000,fffffd806d292600) at ipv4_input+0x48 if_input_local(ffff800000689000,fffffd806d292600,2) at if_input_local+0x10e ip_output(fffffd806d292a00,0,fffffd806f687420,20,0,fffffd806f6873a8,46b983d8eac4981a) at ip_output+0xb05 rip_output(fffffd806d292a00,fffffd807f547978,ffff800021210150,1) at rip_output+0x2cb rip_usrreq(fffffd807f547978,9,fffffd806d292a00,0,0,ffff80002119ed20) at rip_usrreq+0x49c sosend(fffffd807f547978,0,ffff8000212103e0,0,0,0) at sosend+0x632 dofilewritev(ffff80002119ed20,3,ffff8000212103e0,0,ffff8000212104e0) at dofilewritev+0x19c sys_writev(ffff80002119ed20,ffff800021210488,ffff8000212104e0) at sys_writev+0xa7 syscall(ffff800021210550) at syscall+0x489 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4c80, count: -20 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020ce8ff0) at x86_ipi_db+0x1a x86_ipi_handler() at x86_ipi_handler+0xb7 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff829f38d0) at __mp_lock+0x122 syscall(ffff8000211d4830) at syscall+0x3ef Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4c80, count: 9 ddb{1}> trace x86_ipi_db(ffff800020ce8ff0) at x86_ipi_db+0x1a x86_ipi_handler() at x86_ipi_handler+0xb7 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff829f38d0) at __mp_lock+0x122 syscall(ffff8000211d4830) at syscall+0x3ef Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4c80, count: -6 ddb{1}>