uvm_fault(0xfffffd806c210200, 0x0, 0, 1) -> e fatal page fault in supervisor mode trap type 6 code 0 rip ffffffff81374ca8 cs 8 rflags 10207 cr2 0 cpl 0 rsp ffff80002a38db60 gsbase 0xffff8000299edff0 kgsbase 0x0 panic: trap type 6, code=0, pc=ffffffff81374ca8 Starting stack trace... panic(ffffffff833c0ea4) at panic+0x1d0 sys/kern/subr_prf.c:229 kerntrap(ffff80002a38dab0) at kerntrap+0x30b alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dt_ioctl_record_stop(ffff800001479000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:593 dtclose(11e5f,81,2000,ffff80002a290018) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(11e5f,81,2000,ffff80002a290018) at dtclose+0x109 sys/dev/dt/dt_dev.c:239 spec_close(ffff80002a38dc60) at spec_close+0x466 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd807b175d08,81,fffffd80097fb0d0,ffff80002a290018) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8078243988,ffff80002a290018) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8078243988,ffff80002a290018) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd8078243988,ffff80002a290018) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd8078243988,ffff80002a290018) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80002a290018) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80002a290018,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80002a290018,ffff80002a38dfd0,ffff80002a38df20) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80002a38dfd0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a38dfd0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x701c0ea37780, count: 242 End of stack trace. W ARNING: SPL NOT LOWERED ON SYSCALL 83 2136557360 EXIT 0 4 Stopped at savectx+0xae: movl $0,%gs:0x688 TID PID UID PRFLAGS PFLAGS CPU COMMAND * 45592 51477 0 0 0x4000000 1 syz-executor 203581 88101 0 0x100003 0x80 0 getty savectx() at savectx+0xae end of kernel end trace frame: 0xcbda2c798b0, count: 14 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{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic *cpu1: uvm_fault(0xfffffd806c210200, 0x0, 0, 1) -> e ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0xcbda2c798b0, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff80003c466af0 rbx 0 rdx 0xffff800001584540 rcx 0xffff8000fffe2fb8 rax 0x3b r8 0xffff80003c466a20 r9 0x1 r10 0x1d68635f0448f1e8 r11 0x46b49658fe704330 r12 0 r13 0 r14 0xffff8000fffe2fb8 r15 0 rip 0xffffffff8264e3ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff80003c466a70 ss 0x10 savectx+0xae: movl $0,%gs:0x688 ddb{1}> show proc PROC (syz-executor) tid=45592 pid=51477 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=0xffff8000fffe2d20,0xffffffff838b7bd0 process=0xffff8000fffec018 user=0xffff80003c461000, vmspace=0xfffffd806c02b5d8 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 35557 105558 75846 0 2 0 syz-executor 51477 511521 63571 0 2 0 syz-executor *51477 45592 63571 0 7 0x4000000 syz-executor 80461 200898 79715 0 2 0 syz-executor 80461 121161 79715 0 3 0x4000080 fsleep syz-executor 98623 475675 97782 0 2 0x10 syz-executor 98623 16364 97782 0 3 0x4000090 fsleep syz-executor 78152 277092 44314 0 2 0 syz-executor 78152 205962 44314 0 3 0x4000080 fsleep syz-executor 55262 16762 9487 0 2 0 syz-executor 88878 124195 51144 0 3 0x1003000 suspend syz-executor 88878 258243 51144 0 2 0x5081c00 syz-executor 88878 99118 51144 0 2 0x5081000 syz-executor 88878 90584 51144 0 3 0x5081000 pipecl syz-executor 88878 173194 51144 0 3 0x5081000 inode syz-executor 88878 349285 51144 0 3 0x5081000 inode syz-executor 75846 399715 94056 0 2 0xc82 syz-executor 9487 443384 94056 0 2 0x2 syz-executor 97782 512645 94056 0 2 0x2 syz-executor 63571 98887 94056 0 2 0xc82 syz-executor 51144 462858 94056 0 3 0x82 wait syz-executor 4893 494829 6275 0 3 0x100082 sbwait arp 6275 133208 1 0 3 0x10008a sigsusp sh 79715 201956 94056 0 2 0xc82 syz-executor 34038 349178 94056 0 2 0xc82 syz-executor 44314 414097 94056 0 2 0xc82 syz-executor 94056 509019 22174 0 3 0x82 kqread syz-executor 22174 523712 61815 0 3 0x10008a sigsusp ksh 61815 359418 24393 0 3 0x98 kqread sshd-session 24393 193305 12045 0 3 0x92 kqread sshd-session 88101 203581 1 0 7 0x100083 getty 12045 393070 1 0 3 0x88 kqread sshd 45203 483311 71150 74 3 0x1100092 bpf pflogd 71150 238936 1 0 3 0x80 sbwait pflogd 42419 226147 9089 73 3 0x1100090 kqread syslogd 9089 5344 1 0 3 0x100082 sbwait syslogd 40483 486842 1 0 3 0x100080 kqread resolvd 9119 295896 57396 77 3 0x100092 kqread dhcpleased 31599 162464 57396 77 3 0x100092 kqread dhcpleased 57396 312371 1 0 3 0x80 kqread dhcpleased 82540 294054 0 0 3 0x14200 bored smr 44033 104953 0 0 3 0x14200 pgzero zerothread 47328 290704 0 0 3 0x14200 aiodoned aiodoned 38643 37051 0 0 3 0x14200 syncer update 59448 276502 0 0 3 0x14200 cleaner cleaner 60386 114770 0 0 3 0x14200 reaper reaper 31084 444426 0 0 3 0x14200 pgdaemon pagedaemon 53973 24626 0 0 3 0x14200 bored viomb 53508 293180 0 0 3 0x40014200 acpi0 acpi0 66552 400019 0 0 3 0x40014200 idle1 94817 360827 0 0 3 0x14200 bored softnet1 48418 194288 0 0 2 0x14200 softnet0 48752 183247 0 0 2 0x14200 systqmp 44302 194764 0 0 3 0x14200 bored systq 57904 432850 0 0 3 0x14200 tmoslp softclockmp 69659 417155 0 0 3 0x40014200 tmoslp softclock 73808 418596 0 0 3 0x40014200 idle0 1 351427 0 0 3 0x82 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{1}> show all locks Process 88878 (syz-executor) thread 0xffff80002a290d10 (99118) exclusive rrwlock inode r = 0 (0xfffffd80782fd340) #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:765 #9 Xsyscall+0x128 Process 88878 (syz-executor) thread 0xffff80002a290a78 (173194) exclusive rrwlock inode r = 0 (0xfffffd806e1aa418) #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 vfs_lookup+0x11c sys/kern/vfs_lookup.c:-1 #6 namei+0x7ca sys/kern/vfs_lookup.c:250 #7 vn_open+0x1f1 sys/kern/vfs_vnops.c:107 #8 doopenat+0x35b sys/kern/vfs_syscalls.c:1138 #9 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #9 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 #10 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10257 11150K 11354K 166960K 13078 0 pcb 17 14K 30K 166960K 463 0 rtable 151 9K 10K 166960K 738 0 pf 40 18K 20K 166960K 224 0 ifaddr 32 5K 7K 166960K 159 0 ifgroup 64 2K 3K 166960K 270 0 sysctl 4 1K 9K 166960K 18 0 counters 72 37K 38K 166960K 288 0 ioctlops 0 0K 4K 166960K 1816 0 iov 0 0K 24K 166960K 107 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1447 91K 91K 166960K 2910 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 9K 166960K 28 0 VM map 2 1K 1K 166960K 2 0 sem 22 10K 10K 166960K 66 0 dirhash 12 2K 2K 166960K 48 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 20 73K 244K 166960K 1937 0 sigio 0 0K 0K 166960K 95 0 proc 73 115K 180K 166960K 889 0 subproc 81 5K 5K 166960K 155 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 219 0 in_multi 45 3K 6K 166960K 229 0 ether_multi 1 0K 0K 166960K 15 0 mrt 3 0K 0K 166960K 19 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 259 1155K 1155K 166960K 259 0 exec 0 0K 1K 166960K 755 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 2 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 269 180K 188K 166960K 19392 0 UVM aobj 10 2K 2K 166960K 10 0 pinsyscall 46 92K 107K 166960K 3213 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 130 0 NDP 14 0K 1K 166960K 112 0 temp 85 8660K 8774K 166960K 105023 0 kqueue 14 22K 30K 166960K 361 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 120 242 0 238 3 2 1 2 0 8 0 rtentry 176 225 0 174 5 2 3 5 0 8 0 unpcb 144 1626 0 1609 21 17 4 6 0 8 3 syncache 336 8 0 8 3 3 0 1 0 8 0 tcpqe 32 4 0 4 2 2 0 1 0 8 0 tcpcb 736 610 0 605 12 11 1 7 0 8 0 arp 136 35 0 25 1 0 1 1 0 8 0 inpcb 328 2168 0 2160 14 10 4 7 0 8 2 nd6 152 46 0 37 1 0 1 1 0 8 0 pkpcb 40 9 0 9 5 5 0 1 0 8 0 kcovpl 48 17 0 8 1 0 1 1 0 8 0 mppekey 1024 1 0 1 1 1 0 1 0 8 0 ppxss 1192 84 0 84 4 4 0 1 0 8 0 pppxif 1504 12 0 12 3 3 0 1 0 8 0 pffrag 232 56 0 45 1 0 1 1 0 482 0 pffrnode 88 53 0 43 1 0 1 1 0 8 0 pffrent 40 101 0 90 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 24 139 0 68 1 0 1 1 0 8 0 pfstkey 128 139 0 68 3 0 3 3 0 8 0 pfstate 384 139 0 68 8 0 8 8 0 8 0 pfrule 1344 22 0 17 2 1 1 2 0 8 0 rttmr 136 3 0 3 2 1 1 1 0 8 1 art_heap8 4096 5 0 0 5 0 5 5 0 8 0 art_heap4 256 1017 0 802 32 16 16 28 0 8 1 art_table 40 1022 0 802 5 0 5 5 0 8 0 art_node 32 225 0 180 1 0 1 1 0 8 0 sysvmsgpl 40 11 0 8 1 0 1 1 0 8 0 semupl 112 2 0 2 2 2 0 1 0 8 0 semapl 112 60 0 40 1 0 1 1 0 8 0 shmpl 112 7 0 0 1 0 1 1 0 8 0 dirhash 1024 42 0 25 3 0 3 3 0 8 0 dino2pl 256 4972 0 3445 96 0 96 96 0 8 0 ffsino 296 4972 0 3445 119 1 118 118 0 8 0 nchpl 144 7608 0 5891 64 0 64 64 0 8 0 rtmask 32 13 0 13 3 3 0 1 0 8 0 vnodes 216 5860 0 0 326 0 326 326 0 8 0 namei 1024 26812 0 26810 2 1 1 1 0 8 0 percpumem 16 159 0 108 1 0 1 1 0 8 0 kstatmem 264 174 0 142 4 1 3 3 0 8 0 acpiwqpl 32 1 0 1 1 0 1 1 1 8 1 scsiplug 72 8 0 8 4 4 0 1 0 8 0 scxspl 216 42253 0 42253 12 11 1 4 1 8 1 plimitpl 152 526 0 507 1 0 1 1 0 8 0 sigapl 424 2226 0 2176 7 0 7 7 0 8 0 knotepl 120 572 0 0 18 0 18 18 0 8 0 kqueuepl 224 871 0 861 16 14 2 5 0 8 1 pipepl 344 413 0 381 16 12 4 9 0 8 0 fdescpl 528 2202 0 2168 3 0 3 3 0 8 0 filepl 160 14798 0 14560 27 14 13 17 0 8 0 lockfpl 104 777 0 774 2 1 1 2 0 8 0 lockfspl 48 266 0 263 1 0 1 1 0 8 0 sessionpl 144 31 0 22 1 0 1 1 0 8 0 pgrppl 48 254 0 236 1 0 1 1 0 8 0 ucredpl 104 2489 0 2475 1 0 1 1 0 8 0 zombiepl 144 2178 0 2176 1 0 1 1 0 8 0 processpl 1232 2226 0 2176 5 0 5 5 0 8 0 procpl 664 5259 0 5200 7 1 6 7 0 8 0 sosppl 176 10 0 10 4 4 0 1 0 8 0 sockpl 752 4173 0 4144 39 29 10 21 0 8 6 mcl64k 65536 18 0 0 3 0 3 3 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 5 0 0 1 0 1 1 0 8 0 mcl4k 4096 111 0 0 14 0 14 14 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 64 0 0 6 0 6 6 0 8 0 mtagpl 96 5 0 0 1 0 1 1 0 8 0 mbufpl 256 1214 0 0 74 0 74 74 0 8 0 bufpl 280 16703 0 10566 439 0 439 439 0 8 0 anonpl 32 13195 0 0 107 0 107 107 0 246 0 amapchunkpl 152 66272 0 65673 43 16 27 30 0 158 1 amappl16 200 8512 0 8255 57 42 15 29 0 8 1 amappl15 192 19 0 19 1 1 0 1 0 8 0 amappl14 184 4 0 4 1 1 0 1 0 8 0 amappl13 176 494 0 492 1 0 1 1 0 8 0 amappl12 168 2628 0 2582 3 0 3 3 0 8 0 amappl11 160 7 0 7 1 1 0 1 0 8 0 amappl10 152 51 0 37 1 0 1 1 0 8 0 amappl9 144 253 0 253 1 1 0 1 0 8 0 amappl8 136 40 0 38 1 0 1 1 0 8 0 amappl7 128 128 0 126 1 0 1 1 0 8 0 amappl6 120 351 0 335 1 0 1 1 0 8 0 amappl5 112 81 0 68 1 0 1 1 0 8 0 amappl4 104 458 0 427 1 0 1 1 0 8 0 amappl3 96 11576 0 11471 4 1 3 3 0 8 0 amappl2 88 2333 0 2250 2 0 2 2 0 8 0 amappl1 80 17405 0 16783 15 0 15 15 0 8 0 amappl 88 18216 0 18035 5 0 5 5 0 92 0 uvmvnodes 80 5860 0 0 120 0 120 120 0 8 0 dma65536 65536 1 0 1 1 1 0 1 0 8 0 dma8192 8192 1 0 1 1 1 0 1 0 8 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 8 0 8 2 2 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 9 0 0 1 0 1 1 0 8 0 uaddrrnd 24 2202 0 2168 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2202 0 2168 1 0 1 1 0 8 0 vmmpekpl 168 17932 0 17868 3 0 3 3 0 8 0 vmmpepl 168 145757 0 143463 124 23 101 111 0 357 0 vmsppl 488 2201 0 2168 5 0 5 5 0 8 0 rwobjpl 80 45832 0 38742 145 0 145 145 0 8 0 pdppl 4096 4411 0 4336 114 39 75 85 0 8 0 pvpl 32 21055 0 0 170 0 170 170 0 265 0 pmappl 256 2201 0 2168 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 375 0 75 9 0 9 9 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff83823ff0) 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 __mp_lock(ffffffff838b2cf0) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff838b2cf0) at __mp_lock+0x192 sys/kern/kern_lock.c:165 __mp_acquire_count(ffffffff838b2cf0,1) at __mp_acquire_count+0x58 sys/kern/kern_lock.c:-1 sleep_finish(ffffffffffffffff,1) at sleep_finish+0x2d8 sys/kern/kern_synch.c:367 ttread(ffff800000afca00,ffff80002a2d28b8,0) at ttread+0x7de ttysleep_nsec sys/kern/tty.c:2325 [inline] ttread(ffff800000afca00,ffff80002a2d28b8,0) at ttread+0x7de ttysleep sys/kern/tty.c:2315 [inline] ttread(ffff800000afca00,ffff80002a2d28b8,0) at ttread+0x7de sys/kern/tty.c:1587 spec_read(ffff80002a2d2710) at spec_read+0x14b sys/kern/spec_vnops.c:215 VOP_READ(fffffd806fc23890,ffff80002a2d28b8,0,fffffd80097fbc98) at VOP_READ+0x101 sys/kern/vfs_vops.c:227 vn_read(fffffd806e471e70,ffff80002a2d28b8,0) at vn_read+0x17b sys/kern/vfs_vnops.c:369 dofilereadv(ffff80002a272540,0,ffff80002a2d28b8,0,ffff80002a2d2970) at dofilereadv+0x25a sys/kern/sys_generic.c:252 sys_read(ffff80002a272540,ffff80002a2d2a20,ffff80002a2d2970) at sys_read+0xa2 sys/kern/sys_generic.c:172 syscall(ffff80002a2d2a20) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2d2a20) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x75b4bdf24a00, count: 1 ddb{0}> trace x86_ipi_db(ffffffff83823ff0) 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 __mp_lock(ffffffff838b2cf0) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:134 [inline] __mp_lock(ffffffff838b2cf0) at __mp_lock+0x192 sys/kern/kern_lock.c:165 __mp_acquire_count(ffffffff838b2cf0,1) at __mp_acquire_count+0x58 sys/kern/kern_lock.c:-1 sleep_finish(ffffffffffffffff,1) at sleep_finish+0x2d8 sys/kern/kern_synch.c:367 ttread(ffff800000afca00,ffff80002a2d28b8,0) at ttread+0x7de ttysleep_nsec sys/kern/tty.c:2325 [inline] ttread(ffff800000afca00,ffff80002a2d28b8,0) at ttread+0x7de ttysleep sys/kern/tty.c:2315 [inline] ttread(ffff800000afca00,ffff80002a2d28b8,0) at ttread+0x7de sys/kern/tty.c:1587 spec_read(ffff80002a2d2710) at spec_read+0x14b sys/kern/spec_vnops.c:215 VOP_READ(fffffd806fc23890,ffff80002a2d28b8,0,fffffd80097fbc98) at VOP_READ+0x101 sys/kern/vfs_vops.c:227 vn_read(fffffd806e471e70,ffff80002a2d28b8,0) at vn_read+0x17b sys/kern/vfs_vnops.c:369 dofilereadv(ffff80002a272540,0,ffff80002a2d28b8,0,ffff80002a2d2970) at dofilereadv+0x25a sys/kern/sys_generic.c:252 sys_read(ffff80002a272540,ffff80002a2d2a20,ffff80002a2d2970) at sys_read+0xa2 sys/kern/sys_generic.c:172 syscall(ffff80002a2d2a20) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2d2a20) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x75b4bdf24a00, count: -14 ddb{0}> machine ddbcpu 1 Stopped at savectx+0xae: movl $0,%gs:0x688 savectx() at savectx+0xae end of kernel end trace frame: 0xcbda2c798b0, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0xcbda2c798b0, count: -1