*cpu0: uvm_fault(0xfffffd806b9873e8, 0x0, 0, 1) -> e ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x2326e78f410, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff80003c4516b0 rbx 0 rdx 0 rcx 0xffff8000fffefca0 rax 0x32 r8 0xffff80003c4515e0 r9 0x80713 acpi_pdirpa+0x6c584 r10 0x21c4f916d3178df4 r11 0x2045a6beec67a891 r12 0 r13 0 r14 0xffff8000fffefca0 r15 0 rip 0xffffffff817053ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff80003c451630 ss 0x10 savectx+0xae: movl $0,%gs:0x688 ddb{1}> show proc PROC (syz-executor) tid=176872 pid=50011 tcnt=3 stat=onproc flags process=0 proc=4000000 runpri=50, usrpri=50, slppri=17, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000fffee7e0,0xffffffff83909918 process=0xffff80003c425360 user=0xffff80003c44c000, vmspace=0xfffffd806b987018 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 50011 421192 48468 0 2 0 syz-executor 50011 108080 48468 0 2 0x4000000 syz-executor *50011 176872 48468 0 7 0x4000000 syz-executor 41355 334569 16651 0 2 0 syz-executor 41355 383538 16651 0 3 0x4000080 sbwait syz-executor 50388 224232 30046 0 3 0x3000 suspend syz-executor 50388 38226 30046 0 2 0x4081000 syz-executor 50388 424011 30046 0 3 0x4081000 fltagain2 syz-executor 66146 119472 38185 0 3 0x80 nanoslp syz-executor 66146 214715 38185 0 3 0x4000080 kqpoll syz-executor 66146 21017 38185 0 3 0x4000080 fsleep syz-executor 66146 281132 38185 0 3 0x4000080 fsleep syz-executor 35723 425608 13753 0 3 0x80 nanoslp syz-executor 35723 399490 13753 0 3 0x4000080 piperd syz-executor 35723 377905 13753 0 3 0x4000080 fsleep syz-executor 93614 446733 415 0 3 0x80 nanoslp syz-executor 93614 131407 415 0 3 0x4000080 fsleep syz-executor 93614 125139 415 0 3 0x4000080 fsleep syz-executor 93614 58838 415 0 3 0x4000080 lockf syz-executor 77150 31502 27924 0 3 0x3000 suspend syz-executor 77150 356191 27924 0 2 0x4081000 syz-executor 77150 513214 27924 0 3 0x4081000 fltagain2 syz-executor 77150 132659 27924 0 3 0x4081000 pipecl syz-executor 30831 458219 0 0 3 0x14200 acct acct 11764 254436 0 0 3 0x14200 bored sosplice 13753 208258 15827 0 3 0x82 nanoslp syz-executor 38185 205389 15827 0 3 0x82 nanoslp syz-executor 30046 211512 15827 0 3 0x82 nanoslp syz-executor 27924 59679 15827 0 3 0x82 nanoslp syz-executor 48468 183002 15827 0 3 0x82 nanoslp syz-executor 16651 391849 15827 0 3 0x82 nanoslp syz-executor 415 42155 15827 0 3 0x82 nanoslp syz-executor 84008 46154 15827 0 3 0x82 nanoslp syz-executor 15827 172021 69397 0 2 0x82 syz-executor 69397 398721 99451 0 3 0x10008a sigsusp ksh 99451 123451 96360 0 3 0x98 kqread sshd-session 96360 414860 85420 0 3 0x92 kqread sshd-session 95600 340275 1 0 3 0x100083 ttyin getty 85420 413084 1 0 3 0x88 kqread sshd 4149 144523 49402 74 3 0x1100092 bpf pflogd 49402 68305 1 0 3 0x80 sbwait pflogd 22961 309105 39975 73 3 0x1100090 kqread syslogd 39975 207503 1 0 3 0x100082 sbwait syslogd 26720 433257 1 0 3 0x100080 kqread resolvd 91498 137951 73454 77 3 0x100092 kqread dhcpleased 64949 491124 73454 77 3 0x100092 kqread dhcpleased 73454 97405 1 0 3 0x80 kqread dhcpleased 87443 236669 0 0 3 0x14200 bored smr 65964 173433 0 0 3 0x14200 pgzero zerothread 51936 156416 0 0 3 0x14200 aiodoned aiodoned 65885 449493 0 0 3 0x14200 syncer update 15004 51492 0 0 3 0x14200 cleaner cleaner 13113 514678 0 0 3 0x14200 reaper reaper 72889 477817 0 0 3 0x14200 pgdaemon pagedaemon 10479 411399 0 0 3 0x14200 bored viomb 1625 233138 0 0 3 0x40014200 acpi0 acpi0 45872 46925 0 0 3 0x40014200 idle1 74787 492437 0 0 3 0x14200 bored softnet1 38300 293351 0 0 2 0x14200 softnet0 76939 518464 0 0 3 0x14200 bored systqmp 7914 214938 0 0 3 0x14200 bored systq 43627 40196 0 0 3 0x14200 tmoslp softclockmp 70668 466572 0 0 3 0x40014200 tmoslp softclock 86030 48009 0 0 3 0x40014200 idle0 1 468955 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 1: exclusive mutex &map->flags_lock r = 0 (0xfffffd806b987190) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 mtx_enter_try+0x1ad sys/kern/kern_lock.c:311 #2 mtx_enter+0x62 sys/kern/kern_lock.c:261 #3 vm_map_lock_ln+0x66 sys/uvm/uvm_map.c:5155 #4 uvm_mapanon+0x28f sys/uvm/uvm_map.c:-1 #5 uvm_mmapanon+0x1d0 sys/uvm/uvm_mmap.c:1029 #6 sys_mmap+0xa80 sys/uvm/uvm_mmap.c:426 #7 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #7 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:746 #8 Xsyscall+0x128 Process 41355 (syz-executor) thread 0xffff8000fffee018 (383538) exclusive rwlock sbufrcv r = 0 (0xffff800010fca138) #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:870 #4 recvit+0x40b sys/kern/uipc_syscalls.c:1078 #5 sys_recvmmsg+0x410 sys/kern/uipc_syscalls.c:969 #6 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #6 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:746 #7 Xsyscall+0x128 Process 50388 (syz-executor) thread 0xffff80003afeed28 (38226) exclusive rrwlock inode r = 0 (0xfffffd8067230208) #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:746 #9 Xsyscall+0x128 Process 77150 (syz-executor) thread 0xffff80003c4087e8 (356191) exclusive rrwlock inode r = 0 (0xfffffd8067230ec0) #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:746 #9 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10221 11141K 11197K 166960K 11618 0 pcb 18 12K 12K 166960K 59 0 rtable 225 8K 8K 166960K 319 0 pf 38 18K 20K 166960K 70 0 ifaddr 43 7K 7K 166960K 58 0 ifgroup 60 2K 2K 166960K 85 0 sysctl 3 1K 9K 166960K 7 0 counters 70 37K 38K 166960K 112 0 ioctlops 0 0K 4K 166960K 1523 0 iov 1 4K 12K 166960K 13 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1404 88K 89K 166960K 1643 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 6 0 VM map 2 1K 1K 166960K 2 0 sem 11 0K 0K 166960K 15 0 dirhash 12 2K 2K 166960K 15 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 93K 166960K 347 0 sigio 0 0K 0K 166960K 3 0 proc 73 115K 164K 166960K 552 0 subproc 72 4K 4K 166960K 72 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 22 0 in_multi 89 6K 7K 166960K 114 0 ether_multi 1 0K 0K 166960K 4 0 mrt 1 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 389 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 267 160K 172K 166960K 5080 0 UVM aobj 6 2K 2K 166960K 7 0 pinsyscall 43 86K 104K 166960K 1440 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 5 0 NDP 13 0K 2K 166960K 37 0 temp 42 8639K 8705K 166960K 11347 0 kqueue 15 24K 30K 166960K 77 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 26 0 0 1 0 1 1 0 8 0 rtpcb 120 48 0 45 1 0 1 1 0 8 0 rtentry 176 110 0 13 5 0 5 5 0 8 0 unpcb 144 141 0 118 2 0 2 2 0 8 0 syncache 336 6 0 6 1 0 1 1 0 8 1 tcpqe 32 2 0 2 1 1 0 1 0 8 0 tcpcb 736 74 0 67 2 0 2 2 0 8 0 arp 136 14 0 1 1 0 1 1 0 8 0 inpcb 328 299 0 286 7 0 7 7 0 8 5 nd6 144 17 0 2 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 1 0 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1192 19 0 19 1 0 1 1 0 8 1 pppxif 1504 2 0 2 1 0 1 1 0 8 1 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 5 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 pfstitem 24 34 0 1 1 0 1 1 0 8 0 pfstkey 128 34 0 1 2 0 2 2 0 8 0 pfstate 384 33 0 1 4 0 4 4 0 8 0 pfrule 1344 22 0 17 2 1 1 2 0 8 0 rttmr 136 1 0 1 1 1 0 1 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 499 0 91 28 1 27 28 0 8 0 art_table 40 501 0 91 5 0 5 5 0 8 0 art_node 32 110 0 24 1 0 1 1 0 8 0 sysvmsgpl 40 5 0 4 1 0 1 1 0 8 0 semupl 112 4 0 4 1 0 1 1 0 8 1 semapl 112 11 0 2 1 0 1 1 0 8 0 shmpl 112 4 0 1 1 0 1 1 0 8 0 dirhash 1024 19 0 2 3 0 3 3 0 8 0 dino2pl 256 2016 0 504 95 0 95 95 0 8 0 ffsino 296 2016 0 504 117 0 117 117 0 8 0 nchpl 144 2497 0 801 63 0 63 63 0 8 0 rtmask 32 5 0 5 1 0 1 1 0 8 1 uvmvnodes 80 2250 0 0 46 0 46 46 0 8 0 vnodes 216 2250 0 0 125 0 125 125 0 8 0 namei 1024 8634 0 8634 2 1 1 2 0 8 1 percpumem 16 71 0 21 1 0 1 1 0 8 0 kstatmem 264 44 0 16 3 0 3 3 0 8 0 scxspl 216 15799 0 15799 9 1 8 8 1 8 8 plimitpl 152 155 0 136 1 0 1 1 0 8 0 sigapl 424 648 0 598 7 1 6 7 0 8 0 knotepl 120 527 0 0 16 0 16 16 0 8 0 kqueuepl 224 179 0 167 3 0 3 3 0 8 2 pipepl 344 133 0 101 3 0 3 3 0 8 0 fdescpl 528 630 0 598 3 0 3 3 0 8 0 filepl 160 3275 0 2960 14 0 14 14 0 8 0 lockfpl 104 132 0 127 1 0 1 1 0 8 0 lockfspl 48 55 0 51 1 0 1 1 0 8 0 sessionpl 144 25 0 16 1 0 1 1 0 8 0 pgrppl 48 36 0 19 1 0 1 1 0 8 0 ucredpl 104 489 0 475 1 0 1 1 0 8 0 zombiepl 144 601 0 598 1 0 1 1 0 8 0 processpl 1232 648 0 598 5 0 5 5 0 8 0 procpl 664 1054 0 988 7 0 7 7 0 8 0 sosppl 168 5 0 5 1 0 1 1 0 8 1 sockpl 752 496 0 457 10 0 10 10 0 8 5 mcl64k 65536 16 0 0 2 0 2 2 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 119 0 0 15 0 15 15 0 8 0 mcl2k 2048 28 0 0 4 0 4 4 0 8 0 mtagpl 96 5 0 0 1 0 1 1 0 8 0 mbufpl 256 173 0 0 11 0 11 11 0 8 0 bufpl 280 6981 0 838 439 0 439 439 0 8 0 anonpl 32 10785 0 0 87 0 87 87 0 246 0 amapchunkpl 152 15595 0 15029 33 2 31 31 0 158 8 amappl16 200 3113 0 2977 29 4 25 25 0 8 11 amappl15 192 8 0 8 1 1 0 1 0 8 0 amappl14 184 149 0 137 1 0 1 1 0 8 0 amappl13 176 2 0 2 1 1 0 1 0 8 0 amappl12 168 1280 0 1247 4 2 2 3 0 8 0 amappl11 160 54 0 40 1 0 1 1 0 8 0 amappl10 152 22 0 22 1 1 0 1 0 8 0 amappl9 144 254 0 254 1 1 0 1 0 8 0 amappl8 136 29 0 27 1 0 1 1 0 8 0 amappl7 128 124 0 111 1 0 1 1 0 8 0 amappl6 120 176 0 173 1 0 1 1 0 8 0 amappl5 112 117 0 108 1 0 1 1 0 8 0 amappl4 104 301 0 283 1 0 1 1 0 8 0 amappl3 96 2519 0 2406 3 0 3 3 0 8 0 amappl2 88 883 0 802 2 0 2 2 0 8 0 amappl1 80 9748 0 9138 16 2 14 15 0 8 0 amappl 88 4361 0 4170 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 18 0 17 1 0 1 1 0 8 0 aobjpl 72 6 0 1 1 0 1 1 0 8 0 uaddrrnd 24 630 0 598 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 630 0 598 1 0 1 1 0 8 0 vmmpekpl 168 6992 0 6947 3 0 3 3 0 8 0 vmmpepl 168 47675 0 45498 110 0 110 110 0 357 3 vmsppl 488 629 0 598 5 0 5 5 0 8 1 rwobjpl 80 18802 0 15471 75 0 75 75 0 8 1 pdppl 4096 1268 0 1196 100 26 74 86 0 8 2 pvpl 32 18403 0 0 150 1 149 149 0 265 0 pmappl 256 629 0 598 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 272 0 30 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff83821ff0) 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 x86_bus_space_io_read_1(3f8,5) at x86_bus_space_io_read_1+0x37 sys/arch/amd64/amd64/bus_space.c:662 comcnputc(800,6b) at comcnputc+0xd0 comcn_read_reg sys/dev/ic/com.c:1655 [inline] comcnputc(800,6b) at comcnputc+0xd0 sys/dev/ic/com.c:1259 cnputc(6b) at cnputc+0x67 sys/dev/cons.c:218 db_putchar(6b) at db_putchar+0x36d sys/ddb/db_output.c:155 kprintf() at kprintf+0x203 sys/kern/subr_prf.c:723 db_printf(ffffffff833fe3f1) at db_printf+0x9b sys/kern/subr_prf.c:-1 db_ktrap(6,0,ffff800034fe14d0) at db_ktrap+0xe3 db_printtrap sys/arch/amd64/amd64/db_interface.c:99 [inline] db_ktrap(6,0,ffff800034fe14d0) at db_ktrap+0xe3 sys/arch/amd64/amd64/db_interface.c:128 kerntrap(ffff800034fe14d0) at kerntrap+0x23e sys/arch/amd64/amd64/trap.c:480 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dt_ioctl_record_stop(ffff800001472000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:586 dtclose(11e5f,81,2000,ffff80003afeea90) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(11e5f,81,2000,ffff80003afeea90) at dtclose+0x109 sys/dev/dt/dt_dev.c:232 end trace frame: 0xffff800034fe1670, count: 0 ddb{0}> trace x86_ipi_db(ffffffff83821ff0) 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 x86_bus_space_io_read_1(3f8,5) at x86_bus_space_io_read_1+0x37 sys/arch/amd64/amd64/bus_space.c:662 comcnputc(800,6b) at comcnputc+0xd0 comcn_read_reg sys/dev/ic/com.c:1655 [inline] comcnputc(800,6b) at comcnputc+0xd0 sys/dev/ic/com.c:1259 cnputc(6b) at cnputc+0x67 sys/dev/cons.c:218 db_putchar(6b) at db_putchar+0x36d sys/ddb/db_output.c:155 kprintf() at kprintf+0x203 sys/kern/subr_prf.c:723 db_printf(ffffffff833fe3f1) at db_printf+0x9b sys/kern/subr_prf.c:-1 db_ktrap(6,0,ffff800034fe14d0) at db_ktrap+0xe3 db_printtrap sys/arch/amd64/amd64/db_interface.c:99 [inline] db_ktrap(6,0,ffff800034fe14d0) at db_ktrap+0xe3 sys/arch/amd64/amd64/db_interface.c:128 kerntrap(ffff800034fe14d0) at kerntrap+0x23e sys/arch/amd64/amd64/trap.c:480 alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dt_ioctl_record_stop(ffff800001472000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:586 dtclose(11e5f,81,2000,ffff80003afeea90) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(11e5f,81,2000,ffff80003afeea90) at dtclose+0x109 sys/dev/dt/dt_dev.c:232 spec_close(ffff800034fe1680) at spec_close+0x466 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd805dc5b980,81,fffffd80097fb750,ffff80003afeea90) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806b8a9878,ffff80003afeea90) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806b8a9878,ffff80003afeea90) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806b8a9878,ffff80003afeea90) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806b8a9878,ffff80003afeea90) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80003afeea90) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80003afeea90,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003afeea90,ffff800034fe19f0,ffff800034fe1940) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff800034fe19f0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff800034fe19f0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:746 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f4c51865af0, count: -24 ddb{0}> machine ddbcpu 1 Stopped at savectx+0xae: movl $0,%gs:0x688 savectx() at savectx+0xae end of kernel end trace frame: 0x2326e78f410, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x2326e78f410, count: -1