uvm_fault(0xfffffd800b063000, 0x0, 0, 1) -> e fatal page fault in supervisor mode trap type 6 code 0 rip ffffffff815c28f8 cs 8 rflags 10207 cr2 0 cpl 0 rsp ffff80002a33a9c0 gsbase 0xffff8000299ddff0 kgsbase 0x0 panic: trap type 6, code=0, pc=ffffffff815c28f8 Starting stack trace... panic(ffffffff833e3708) at panic+0x1d0 sys/kern/subr_prf.c:229 kerntrap(ffff80002a33a910) at kerntrap+0x30b alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dt_ioctl_record_stop(ffff800001782000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:593 dtclose(11e5f,81,2000,ffff8000ffff2548) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline] dtclose(11e5f,81,2000,ffff8000ffff2548) at dtclose+0x109 sys/dev/dt/dt_dev.c:239 spec_close(ffff80002a33aac0) at spec_close+0x466 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8063788450,81,fffffd80097fd478,ffff8000ffff2548) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806cf505c8,ffff8000ffff2548) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806cf505c8,ffff8000ffff2548) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806cf505c8,ffff8000ffff2548) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806cf505c8,ffff8000ffff2548) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff8000ffff2548) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff8000ffff2548,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000ffff2548,ffff80002a33ae30,ffff80002a33ad80) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80002a33ae30) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a33ae30) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7b7015f9ad10, count: 242 End of stack trace. WA RNING: SPL NOT LOWERED ON SYSCALL 49 0 EXIT 0 4 Stopped at savectx+0xae: movl $0,%gs:0x688 TID PID UID PRFLAGS PFLAGS CPU COMMAND *470771 35822 0 0 0 1 syz-executor 427453 72443 0 0x2 0x1 0K syz-executor savectx() at savectx+0xae end of kernel end trace frame: 0x7ed8c24f0680, 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(0xfffffd800b063000, 0x0, 0, 1) -> e ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x7ed8c24f0680, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff80002a2da1c0 rbx 0 rdx 0 rcx 0xffff8000fffde030 rax 0x32 r8 0xffff80002a2da0f0 r9 0x2080713 __kernel_phys_base+0x1080713 r10 0xd52e7876a03d1ccc r11 0x8e66ca3e43452f01 r12 0 r13 0 r14 0xffff8000fffde030 r15 0 rip 0xffffffff810c93ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff80002a2da140 ss 0 savectx+0xae: movl $0,%gs:0x688 ddb{1}> show proc PROC (syz-executor) tid=470771 pid=35822 tcnt=2 stat=onproc flags process=0 proc=0 runpri=86, usrpri=86, slppri=36, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000fffdf788,0xffff8000fffde2d8 process=0xffff8000fffec9b8 user=0xffff80002a2d5000, vmspace=0xfffffd800b0631e8 estcpu=36, cpticks=5, pctcpu=0.0, user=5, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND *35822 470771 78485 0 7 0 syz-executor 35822 1768 78485 0 3 0x4000080 fsleep syz-executor 82346 392264 99578 0 2 0 syz-executor 82346 434880 99578 0 3 0x4000080 fsleep syz-executor 82346 403206 99578 0 3 0x4000080 fsleep syz-executor 38014 101548 87495 0 2 0 syz-executor 38014 9156 87495 0 3 0x4000080 kqread syz-executor 38014 518795 87495 0 2 0x4000000 syz-executor 92078 266101 83257 0 3 0x80 nanoslp syz-executor 92078 405170 83257 0 3 0x4000080 kqread syz-executor 92078 137093 83257 0 3 0x4000080 fsleep syz-executor 83257 406826 72443 0 3 0x82 nanoslp syz-executor 64203 300589 72443 0 3 0x82 nanoslp syz-executor 22352 387803 72443 0 3 0x82 nanoslp syz-executor 57427 45766 1 0 2 0x100083 getty 84542 62520 72443 0 3 0x82 nanoslp syz-executor 87495 108393 72443 0 3 0x82 nanoslp syz-executor 78485 227965 72443 0 3 0x82 nanoslp syz-executor 88784 475483 72443 0 2 0x3 syz-executor 99578 234332 72443 0 3 0x82 nanoslp syz-executor 72443 427453 50878 0 7 0x3 syz-executor 50878 277370 90144 0 3 0x10008a sigsusp ksh 90144 9646 13854 0 3 0x98 kqread sshd-session 13854 518215 45192 0 3 0x92 kqread sshd-session 45192 458703 1 0 3 0x88 kqread sshd 61177 428212 61354 74 3 0x1100092 bpf pflogd 61354 346508 1 0 3 0x80 sbwait pflogd 29620 199513 74613 73 3 0x1100090 kqread syslogd 74613 24906 1 0 3 0x100082 sbwait syslogd 5445 143787 1 0 3 0x100080 kqread resolvd 4609 155324 16433 77 3 0x100092 kqread dhcpleased 9242 304547 16433 77 3 0x100092 kqread dhcpleased 16433 107109 1 0 3 0x80 kqread dhcpleased 48510 374966 0 0 3 0x14200 bored smr 22577 341764 0 0 2 0x14200 zerothread 67159 23332 0 0 3 0x14200 aiodoned aiodoned 75315 209845 0 0 3 0x14200 syncer update 98523 206712 0 0 3 0x14200 cleaner cleaner 75032 180898 0 0 2 0x14200 reaper 94539 482707 0 0 3 0x14200 pgdaemon pagedaemon 60581 147025 0 0 3 0x14200 bored viomb 15469 480066 0 0 3 0x40014200 acpi0 acpi0 83260 127264 0 0 3 0x40014200 idle1 89 325780 0 0 3 0x14200 bored softnet1 52212 97889 0 0 2 0x14200 softnet0 48644 437486 0 0 2 0x14200 systqmp 95350 216969 0 0 3 0x14200 bored systq 90699 447191 0 0 3 0x14200 tmoslp softclockmp 88953 317650 0 0 3 0x40014200 tmoslp softclock 29909 278728 0 0 3 0x40014200 idle0 1 327117 0 0 3 0x80082 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb{1}> show all locks Process 72443 (syz-executor) thread 0xffff80002a2622a8 (427453) exclusive rrwlock inode r = 0 (0xfffffd807bb4bb60) #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+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570 #5 vget+0x2a2 sys/kern/vfs_subr.c:686 #6 ktrwriteraw+0x175 sys/kern/kern_ktrace.c:688 #7 ktrgenio+0x2b3 ktrwrite2 sys/kern/kern_ktrace.c:653 [inline] #7 ktrgenio+0x2b3 sys/kern/kern_ktrace.c:264 #8 dofilewritev+0x502 sys/kern/sys_generic.c:398 #9 sys_write+0xa2 sys/kern/sys_generic.c:300 #10 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] #10 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 #11 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11127 12198K 13435K 166960K 16908 0 pcb 17 18K 20K 166960K 1007 0 rtable 268 15K 15K 166960K 1472 0 pf 42 19K 82K 166960K 452 0 ifaddr 44 9K 10K 166960K 297 0 ifgroup 59 2K 2K 166960K 493 0 sysctl 4 1K 9K 166960K 46 0 counters 72 37K 38K 166960K 652 0 ioctlops 0 0K 4K 166960K 2905 0 iov 0 0K 24K 166960K 269 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1564 98K 99K 166960K 5163 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 3 6K 13K 166960K 59 0 VM map 2 1K 1K 166960K 2 0 sem 26 137K 137K 166960K 128 0 dirhash 12 2K 3K 166960K 84 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 15 53K 240K 166960K 4504 0 sigio 0 0K 0K 166960K 77 0 proc 73 115K 180K 166960K 1517 0 subproc 72 4K 4K 166960K 236 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 903 0 in_multi 92 6K 7K 166960K 494 0 ether_multi 1 0K 0K 166960K 64 0 mrt 2 0K 0K 166960K 49 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 283 1261K 1261K 166960K 283 0 exec 0 0K 1K 166960K 1161 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 7 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 238 160K 187K 166960K 42371 0 UVM aobj 26 18K 20K 166960K 33 0 pinsyscall 40 80K 107K 166960K 6154 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 373 0 NDP 15 0K 1K 166960K 218 0 temp 121 8681K 8936K 166960K 209869 0 kqueue 15 24K 33K 166960K 851 0 SYN cache 2 8K 16K 166960K 3 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 120 697 0 694 11 10 1 5 0 8 0 rtentry 176 463 0 361 5 0 5 5 0 8 0 unpcb 144 2818 0 2799 25 19 6 6 0 8 5 syncache 336 26 0 26 5 5 0 1 0 8 0 tcpqe 32 11 0 11 5 5 0 1 0 8 0 tcpcb 736 1390 0 1382 27 25 2 8 0 8 1 arp 136 64 0 47 1 0 1 1 0 8 0 inpcb 328 4991 0 4978 51 47 4 16 0 8 2 nd6 152 89 0 63 2 1 1 2 0 8 0 pkpcb 40 62 0 62 5 4 1 1 0 8 1 kcovpl 48 26 0 18 1 0 1 1 0 8 0 mppekey 1024 2 0 2 2 2 0 1 0 8 0 ppxss 1192 233 0 233 3 2 1 1 0 8 1 pppxif 1504 91 0 91 8 7 1 1 0 8 1 pfstscr 40 43 0 43 1 1 0 1 0 8 0 pffrag 232 42 0 29 1 0 1 1 0 482 0 pffrnode 88 38 0 26 1 0 1 1 0 8 0 pffrent 40 86 0 73 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 pfrktable 1344 11 0 10 1 0 1 1 0 8 0 pftag 88 3 0 0 1 0 1 1 0 8 0 pfstitem 24 272 0 163 1 0 1 1 0 8 0 pfstkey 128 331 0 222 4 0 4 4 0 8 0 pfstate 448 316 0 210 12 0 12 12 0 8 0 pfrule 1344 47 0 41 2 1 1 2 0 8 0 rttmr 136 10 0 10 7 7 0 1 0 8 0 art_heap8 4096 4 0 1 4 1 3 3 0 8 0 art_heap4 256 1908 0 1460 43 15 28 31 0 8 0 art_table 40 1912 0 1461 5 0 5 5 0 8 0 art_node 32 458 0 367 1 0 1 1 0 8 0 sysvmsgpl 40 36 0 26 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 119 0 95 1 0 1 1 0 8 0 shmpl 112 16 0 1 1 0 1 1 0 8 0 dirhash 1024 67 0 50 3 0 3 3 0 8 0 dino2pl 256 9636 0 8095 97 0 97 97 0 8 0 ffsino 296 9636 0 8095 120 0 120 120 0 8 0 nchpl 144 15430 0 13674 66 0 66 66 0 8 0 rtmask 32 42 0 42 6 5 1 1 0 8 1 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 58787 0 58787 2 1 1 2 0 8 1 percpumem 16 341 0 290 1 0 1 1 0 8 0 vcpupl 3968 11 0 3 1 0 1 1 0 8 0 vmpool 848 14 0 6 2 0 2 2 0 8 1 kstatmem 264 318 0 288 8 5 3 3 0 8 0 acpiwqpl 32 2 0 2 1 0 1 1 1 8 1 scsiplug 72 29 0 29 9 8 1 1 0 8 1 scxspl 216 100160 0 100159 14 13 1 8 1 8 0 plimitpl 152 1358 0 1340 1 0 1 1 0 8 0 sigapl 424 4756 0 4709 8 2 6 8 0 8 0 knotepl 120 832 0 0 24 0 24 24 0 8 0 kqueuepl 224 1893 0 1882 20 15 5 5 0 8 4 pipepl 344 650 0 622 12 9 3 6 0 8 0 fdescpl 528 4706 0 4677 3 0 3 3 0 8 0 filepl 160 34733 0 34475 39 24 15 20 0 8 1 lockfpl 104 1286 0 1283 1 0 1 1 0 8 0 lockfspl 48 534 0 531 1 0 1 1 0 8 0 sessionpl 144 62 0 53 1 0 1 1 0 8 0 pgrppl 48 141 0 124 1 0 1 1 0 8 0 ucredpl 104 6046 0 6032 1 0 1 1 0 8 0 zombiepl 144 7017 0 7014 1 0 1 1 0 8 0 processpl 1232 4756 0 4709 6 1 5 6 0 8 0 procpl 664 12004 0 11947 8 2 6 8 0 8 0 sosppl 176 32 0 32 7 7 0 1 0 8 0 sockpl 752 8734 0 8699 80 67 13 22 0 8 8 mcl64k 65536 24 0 0 3 0 3 3 0 8 0 mcl16k 16384 7 0 0 1 0 1 1 0 8 0 mcl12k 12288 5 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 135 0 0 17 0 17 17 0 8 0 mcl2k 2048 50 0 0 6 0 6 6 0 8 0 mtagpl 96 115 0 0 3 0 3 3 0 8 0 mbufpl 256 1307 0 0 80 0 80 80 0 8 0 bufpl 280 39934 0 33798 439 0 439 439 0 8 0 anonpl 32 16686 0 0 134 0 134 134 0 246 0 amapchunkpl 152 146191 0 145640 63 28 35 36 0 158 7 amappl16 200 14632 0 14584 104 91 13 36 0 8 3 amappl15 192 93 0 93 1 1 0 1 0 8 0 amappl14 184 8 0 7 1 0 1 1 0 8 0 amappl13 176 653 0 652 1 0 1 1 0 8 0 amappl12 168 5280 0 5239 3 0 3 3 0 8 0 amappl11 160 41 0 40 4 3 1 1 0 8 0 amappl10 152 49 0 35 1 0 1 1 0 8 0 amappl9 144 244 0 244 1 1 0 1 0 8 0 amappl8 136 28 0 25 1 0 1 1 0 8 0 amappl7 128 162 0 160 1 0 1 1 0 8 0 amappl6 120 527 0 511 1 0 1 1 0 8 0 amappl5 112 96 0 85 1 0 1 1 0 8 0 amappl4 104 627 0 597 1 0 1 1 0 8 0 amappl3 96 30386 0 30286 5 1 4 4 0 8 0 amappl2 88 882 0 819 2 0 2 2 0 8 0 amappl1 80 33798 0 33216 17 3 14 15 0 8 0 amappl 88 40474 0 40315 5 0 5 5 0 92 0 uvmvnodes 80 215 0 0 5 0 5 5 0 8 0 dma65536 65536 5 0 5 4 4 0 1 0 8 0 dma8192 8192 1 0 1 1 1 0 1 0 8 0 dma4096 4096 2 0 2 2 2 0 1 0 8 0 dma2048 2048 1 0 1 1 1 0 1 0 8 0 dma1024 1024 3 0 2 1 0 1 1 0 8 0 dma512 512 1 0 1 1 1 0 1 0 8 0 dma256 256 7 0 7 2 1 1 1 0 8 1 dma128 128 265 0 265 7 7 0 1 0 8 0 dma64 64 9 0 9 4 4 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 83 0 82 1 0 1 1 0 8 0 aobjpl 72 32 0 7 1 0 1 1 0 8 0 uaddrrnd 24 4706 0 4677 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4706 0 4677 1 0 1 1 0 8 0 vmmpekpl 168 35559 0 35498 4 0 4 4 0 8 0 vmmpepl 168 305580 0 303723 151 47 104 116 0 357 4 vmsppl 488 4705 0 4675 5 0 5 5 0 8 0 rwobjpl 80 79456 0 78270 44 7 37 38 0 8 0 pdppl 4096 9448 0 9370 154 72 82 88 0 8 4 pvpl 32 25196 0 0 202 0 202 202 0 265 0 pmappl 256 4719 0 4681 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 472 0 131 10 0 10 10 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff8381dff0) 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 Xsoftclock() at Xsoftclock+0x1d buf_get(fffffd806c85ede0,3d,4000) at buf_get+0x622 sys/kern/vfs_bio.c:1170 getblk(fffffd806c85ede0,3d,4000,0,ffffffffffffffff) at getblk+0x146 sys/kern/vfs_bio.c:-1 ffs2_balloc(fffffd807bb4bac0,f4000,9a,fffffd80097fd478,1,ffff80002a2d43c8) at ffs2_balloc+0x179c sys/ufs/ffs/ffs_balloc.c:-1 ffs_write(ffff80002a2d4450) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345 VOP_WRITE(fffffd806c85ede0,ffff80002a2d4500,3,fffffd80097fd478) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245 ktrwriteraw(ffff80002a2622a8,fffffd806c85ede0,fffffd80097fd478,ffff80002a2d45d8,ffff80002a2d45b0) at ktrwriteraw+0x1be sys/kern/kern_ktrace.c:691 ktrgenio(ffff80002a2622a8,3,1,ffff80000182cad0,180) at ktrgenio+0x2b3 ktrwrite2 sys/kern/kern_ktrace.c:653 [inline] ktrgenio(ffff80002a2622a8,3,1,ffff80000182cad0,180) at ktrgenio+0x2b3 sys/kern/kern_ktrace.c:264 dofilewritev(ffff80002a2622a8,3,ffff80002a2d4768,0,ffff80002a2d4820) at dofilewritev+0x502 sys/kern/sys_generic.c:398 sys_write(ffff80002a2622a8,ffff80002a2d48d0,ffff80002a2d4820) at sys_write+0xa2 sys/kern/sys_generic.c:300 syscall(ffff80002a2d48d0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2d48d0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 end trace frame: 0xffff80002a2d4950, count: 0 ddb{0}> trace x86_ipi_db(ffffffff8381dff0) 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 Xsoftclock() at Xsoftclock+0x1d buf_get(fffffd806c85ede0,3d,4000) at buf_get+0x622 sys/kern/vfs_bio.c:1170 getblk(fffffd806c85ede0,3d,4000,0,ffffffffffffffff) at getblk+0x146 sys/kern/vfs_bio.c:-1 ffs2_balloc(fffffd807bb4bac0,f4000,9a,fffffd80097fd478,1,ffff80002a2d43c8) at ffs2_balloc+0x179c sys/ufs/ffs/ffs_balloc.c:-1 ffs_write(ffff80002a2d4450) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345 VOP_WRITE(fffffd806c85ede0,ffff80002a2d4500,3,fffffd80097fd478) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245 ktrwriteraw(ffff80002a2622a8,fffffd806c85ede0,fffffd80097fd478,ffff80002a2d45d8,ffff80002a2d45b0) at ktrwriteraw+0x1be sys/kern/kern_ktrace.c:691 ktrgenio(ffff80002a2622a8,3,1,ffff80000182cad0,180) at ktrgenio+0x2b3 ktrwrite2 sys/kern/kern_ktrace.c:653 [inline] ktrgenio(ffff80002a2622a8,3,1,ffff80000182cad0,180) at ktrgenio+0x2b3 sys/kern/kern_ktrace.c:264 dofilewritev(ffff80002a2622a8,3,ffff80002a2d4768,0,ffff80002a2d4820) at dofilewritev+0x502 sys/kern/sys_generic.c:398 sys_write(ffff80002a2622a8,ffff80002a2d48d0,ffff80002a2d4820) at sys_write+0xa2 sys/kern/sys_generic.c:300 syscall(ffff80002a2d48d0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2d48d0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x74f061043190, count: -15 ddb{0}> machine ddbcpu 1 Stopped at savectx+0xae: movl $0,%gs:0x688 savectx() at savectx+0xae end of kernel end trace frame: 0x7ed8c24f0680, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x7ed8c24f0680, count: -1