panic: vop_genWARNING: SPL NOT LOWERED ON SYSCALL 4 5 EXIT 0 d Stopped at savectx+0xae: movl $0,%gs:0x680 TID PID UID PRFLAGS PFLAGS CPU COMMAND 13022 11814 0 0x9000000 0x4000000 0 syz-executor.2 * 92287 92273 0 0x1a000002 0x4000000 1 syz-fuzzer savectx() at savectx+0xae end of kernel end trace frame: 0x2f19c3d10, 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}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic *cpu0: vop_generic_badop ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x2f19c3d10, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff80002a23a5c0 rbx 0 rdx 0 rcx 0xffff8000ffff62a8 rax 0x31 r8 0xffff80002a23a4f0 r9 0x1 r10 0x22c68903c99fcedf r11 0x73db5dc37f7175a4 r12 0 r13 0 r14 0xffff8000ffff62a8 r15 0 rip 0xffffffff8250e3ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff80002a23a540 ss 0x10 savectx+0xae: movl $0,%gs:0x680 ddb{1}> show proc PROC (syz-fuzzer) tid=92287 pid=92273 tcnt=16 stat=onproc flags process=1a000002 proc=4000000 runpri=76, usrpri=76, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 forw=0xffffffffffffffff, list=0xffff8000ffff6018,0xffff8000ffff6548 process=0xffff8000ffff9640 user=0xffff80002a235000, vmspace=0xfffffd807f0031b8 estcpu=26, cpticks=1, pctcpu=1.3, user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 11814 66165 19672 0 2 0x9000000 syz-executor.2 11814 13022 19672 0 7 0xd000000 syz-executor.2 84201 155530 87165 0 2 0x8000000 syz-executor.7 84201 26350 87165 0 3 0xc000080 kqread syz-executor.7 17640 157978 2085 0 2 0x8000000 syz-executor.3 17640 42279 2085 0 3 0xc000080 kqpoll syz-executor.3 98998 168879 92273 0 2 0x8000002 syz-executor.0 20828 420392 97346 0 3 0x8000080 nanoslp syz-executor.1 20828 447254 97346 0 3 0xc000080 sbwait syz-executor.1 20828 389606 97346 0 3 0xc000080 fsleep syz-executor.1 10697 361203 74059 0 3 0x8000080 nanoslp syz-executor.5 10697 407739 74059 0 3 0xc000080 kqsel syz-executor.5 10697 455702 74059 0 3 0xc000080 fsleep syz-executor.5 38247 122252 24417 0 3 0x8000080 nanoslp syz-executor.4 38247 361893 24417 0 3 0xc000080 fsleep syz-executor.4 38247 161310 24417 0 3 0xc000080 lockf syz-executor.4 38247 63722 24417 0 3 0xc000080 fsleep syz-executor.4 74059 97832 92273 0 3 0x8000082 nanoslp syz-executor.5 97346 507250 92273 0 3 0x8000082 nanoslp syz-executor.1 86363 192084 0 0 3 0x14200 acct acct 3776 153605 92273 0 2 0x8000002 syz-executor.6 24417 368014 92273 0 3 0x8000082 nanoslp syz-executor.4 2085 183084 92273 0 3 0x8000082 nanoslp syz-executor.3 68180 30495 1 0 3 0x18100083 ttyin getty 19672 123149 92273 0 3 0x8000082 nanoslp syz-executor.2 57126 233986 0 0 3 0x14200 bored sosplice 87165 139924 92273 0 3 0x8000082 nanoslp syz-executor.7 92273 199411 20089 0 3 0x1a000082 wait syz-fuzzer 92273 125712 20089 0 3 0x1e000082 nanoslp syz-fuzzer 92273 410230 20089 0 3 0x1e000082 wait syz-fuzzer 92273 211425 20089 0 3 0x1e000082 thrsleep syz-fuzzer 92273 115786 20089 0 3 0x1e000082 wait syz-fuzzer 92273 411503 20089 0 3 0x1e000082 wait syz-fuzzer 92273 379934 20089 0 3 0x1e000082 thrsleep syz-fuzzer *92273 92287 20089 0 7 0x1e000002 syz-fuzzer 92273 16495 20089 0 3 0x1e000082 wait syz-fuzzer 92273 72431 20089 0 3 0x1e000082 thrsleep syz-fuzzer 92273 12802 20089 0 3 0x1e000082 thrsleep syz-fuzzer 92273 395631 20089 0 3 0x1e000082 thrsleep syz-fuzzer 92273 25007 20089 0 2 0x1e000002 syz-fuzzer 92273 514837 20089 0 3 0x1e000082 wait syz-fuzzer 92273 73299 20089 0 3 0x1e000082 wait syz-fuzzer 92273 77728 20089 0 3 0x1e000082 wait syz-fuzzer 20089 2055 5048 0 3 0x810008a sigsusp ksh 5048 161600 76331 0 3 0x1800009a kqread sshd 76331 214854 1 0 3 0x18000088 kqread sshd 78691 521160 89148 73 3 0x19100090 kqread syslogd 89148 153997 1 0 3 0x18100082 sbwait syslogd 54952 259171 1 0 3 0x18100080 kqread resolvd 8308 245453 56695 77 3 0x18100092 kqread dhcpleased 69054 200225 56695 77 3 0x18100092 kqread dhcpleased 56695 306204 1 0 3 0x18000080 kqread dhcpleased 1177 290981 0 0 3 0x14200 bored smr 86480 202350 0 0 2 0x14200 zerothread 74195 37123 0 0 3 0x14200 aiodoned aiodoned 11103 454177 0 0 3 0x14200 syncer update 42334 175382 0 0 3 0x14200 cleaner cleaner 66687 212485 0 0 3 0x14200 reaper reaper 4977 57084 0 0 3 0x14200 pgdaemon pagedaemon 38152 481718 0 0 3 0x14200 bored viomb 40 153865 0 0 3 0x40014200 acpi0 acpi0 45903 84806 0 0 3 0x40014200 idle1 1259 494960 0 0 3 0x14200 bored softnet3 8375 94603 0 0 3 0x14200 bored softnet2 6853 157759 0 0 3 0x14200 bored softnet1 34961 27735 0 0 3 0x14200 bored softnet0 96873 42126 0 0 3 0x14200 bored systqmp 27832 256258 0 0 3 0x14200 bored systq 13870 126473 0 0 3 0x14200 tmoslp softclockmp 35211 392544 0 0 3 0x40014200 tmoslp softclock 82618 227812 0 0 3 0x40014200 idle0 1 109675 0 0 3 0x8000082 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 1: exclusive sched_lock &sched_lock r = 0 (0xffffffff82e912d8) #0 witness_lock+0x446 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x446 sys/kern/subr_witness.c:1187 #1 wakeup_n+0x58 sys/kern/kern_synch.c:542 #2 knote_enqueue+0x19e klist_empty sys/sys/event.h:362 [inline] #2 knote_enqueue+0x19e kqueue_wakeup sys/kern/kern_event.c:1689 [inline] #2 knote_enqueue+0x19e sys/kern/kern_event.c:2032 #3 knote_locked+0x18d #4 pipe_write+0x7f7 pipe_wakeup sys/kern/sys_pipe.c:375 [inline] #4 pipe_write+0x7f7 sys/kern/sys_pipe.c:662 #5 dofilewritev+0x1a9 sys/kern/sys_generic.c:375 #6 sys_write+0x87 sys/kern/sys_generic.c:295 #7 syscall+0x8cf mi_syscall sys/sys/syscall_mi.h:180 [inline] #7 syscall+0x8cf sys/arch/amd64/amd64/trap.c:577 #8 Xsyscall+0x128 exclusive mutex &kq->kq_lock r = 0 (0xfffffd806eedd010) #0 witness_lock+0x446 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x446 sys/kern/subr_witness.c:1187 #1 mtx_enter_try+0x103 #2 mtx_enter+0x4e sys/kern/kern_lock.c:266 #3 knote_locked+0x108 knote_activate sys/kern/kern_event.c:1816 [inline] #3 knote_locked+0x108 sys/kern/kern_event.c:1848 #4 pipe_write+0x7f7 pipe_wakeup sys/kern/sys_pipe.c:375 [inline] #4 pipe_write+0x7f7 sys/kern/sys_pipe.c:662 #5 dofilewritev+0x1a9 sys/kern/sys_generic.c:375 #6 sys_write+0x87 sys/kern/sys_generic.c:295 #7 syscall+0x8cf mi_syscall sys/sys/syscall_mi.h:180 [inline] #7 syscall+0x8cf sys/arch/amd64/amd64/trap.c:577 #8 Xsyscall+0x128 Process 11814 (syz-executor.2) thread 0xffff8000ffff7728 (13022) Process 98998 (syz-executor.0) thread 0xffff80002f0cf220 (168879) Process 3776 (syz-executor.6) thread 0xffff80002f0cf4b0 (153605) Process 92273 (syz-fuzzer) thread 0xffff8000ffff62a8 (92287) ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10215 6446K 7086K 166960K 13593 0 pcb 18 13K 14K 166960K 351 0 rtable 253 15K 16K 166960K 1240 0 pf 33 9K 10K 166960K 130 0 ifaddr 46 16K 16K 166960K 162 0 ifgroup 58 2K 3K 166960K 214 0 sysctl 3 0K 0K 166960K 5 0 counters 68 36K 37K 166960K 144 0 ioctlops 0 0K 4K 166960K 1586 0 iov 0 0K 16K 166960K 136 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1402 88K 88K 166960K 2851 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 13K 166960K 53 0 VM map 2 1K 1K 166960K 2 0 sem 15 1K 1K 166960K 44 0 dirhash 12 2K 2K 166960K 42 0 ACPI 1697 195K 286K 166960K 12548 0 file desc 16 57K 93K 166960K 2085 0 sigio 0 0K 0K 166960K 41 0 proc 58 79K 115K 166960K 1317 0 subproc 104 6K 7K 166960K 403 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 343 0 in_multi 95 7K 7K 166960K 413 0 ether_multi 1 0K 0K 166960K 7 0 mrt 1 0K 0K 166960K 7 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 235 1049K 1049K 166960K 235 0 exec 0 0K 1K 166960K 898 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 289 97K 113K 166960K 19808 0 UVM aobj 95 5K 5K 166960K 98 0 pinsyscall 36 72K 100K 166960K 3857 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 123 0 NDP 15 0K 2K 166960K 113 0 temp 79 6820K 7315K 166960K 48507 0 kqueue 13 20K 28K 166960K 283 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 24 0 0 1 0 1 1 0 8 0 rtpcb 120 261 0 258 1 0 1 1 0 8 0 rtentry 112 417 0 303 4 0 4 4 0 8 0 unpcb 144 1355 0 1337 2 1 1 2 0 8 0 syncache 336 4 0 4 1 1 0 1 0 8 0 sackhl 24 2 0 2 2 2 0 1 0 8 0 tcpqe 32 59 0 59 3 3 0 1 0 8 0 tcpcb 808 548 0 543 13 12 1 5 0 8 0 arp 120 71 0 52 1 0 1 1 0 8 0 inpcb 384 2161 0 2148 33 30 3 8 0 8 1 nd6 136 109 0 82 1 0 1 1 0 8 0 pkpcb 40 10 0 10 8 8 0 1 0 8 0 kcovpl 48 31 0 23 1 0 1 1 0 8 0 ppxss 1168 5 0 5 4 4 0 1 0 8 0 pffrag 232 28 0 28 1 1 0 1 0 482 0 pffrnode 88 28 0 28 1 1 0 1 0 8 0 pffrent 40 130 0 130 1 1 0 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 24 193 0 167 1 0 1 1 0 8 0 pfstkey 128 193 0 167 2 0 2 2 0 8 0 pfstate 376 193 0 167 6 1 5 5 0 8 0 pfrule 1344 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 1550 0 1093 48 19 29 30 0 8 0 art_table 32 1551 0 1093 4 0 4 4 0 8 0 art_node 16 405 0 304 1 0 1 1 0 8 0 sysvmsgpl 40 15 0 7 1 0 1 1 0 8 0 semupl 112 2 0 2 2 2 0 1 0 8 0 semapl 112 38 0 25 1 0 1 1 0 8 0 shmpl 112 95 0 3 3 0 3 3 0 8 0 dirhash 1024 37 0 20 3 0 3 3 0 8 0 dino2pl 256 4543 0 3025 96 0 96 96 0 8 0 ffsino 272 4543 0 3025 102 0 102 102 0 8 0 nchpl 144 7639 0 5897 67 1 66 67 0 8 0 uvmvnodes 80 5674 0 0 116 0 116 116 0 8 0 vnodes 216 5674 0 0 316 0 316 316 0 8 0 namei 1024 27689 0 27687 17 16 1 2 0 8 0 percpumem 16 86 0 38 1 0 1 1 0 8 0 vcpupl 3904 8 0 0 1 0 1 1 0 8 0 vmpool 696 12 0 4 1 0 1 1 0 8 0 kstatmem 264 102 0 76 2 0 2 2 0 8 0 scsiplug 72 3 0 3 3 3 0 1 0 8 0 scxspl 216 54942 0 54942 16 15 1 8 1 8 1 plimitpl 152 437 0 421 1 0 1 1 0 8 0 sigapl 424 2349 0 2302 7 1 6 7 0 8 0 futexpl 64 31480 0 31476 9 8 1 1 0 8 0 knotepl 120 524 0 0 11 0 11 11 0 8 0 kqueuepl 216 543 0 532 1 0 1 1 0 8 0 pipepl 320 465 0 437 3 0 3 3 0 8 0 fdescpl 496 2329 0 2302 7 3 4 5 0 8 0 filepl 152 14599 0 14349 20 9 11 13 0 8 0 lockfpl 104 702 0 698 1 0 1 1 0 8 0 lockfspl 48 252 0 249 1 0 1 1 0 8 0 sessionpl 144 52 0 36 1 0 1 1 0 8 0 pgrppl 48 110 0 94 1 0 1 1 0 8 0 ucredpl 104 2508 0 2498 1 0 1 1 0 8 0 zombiepl 144 2302 0 2302 1 0 1 1 0 8 1 processpl 1136 2349 0 2302 4 0 4 4 0 8 0 procpl 656 4436 0 4364 7 0 7 7 0 8 0 srpgc 96 20 0 20 6 5 1 1 0 8 1 sosppl 168 35 0 35 14 13 1 1 0 8 1 sockpl 664 3812 0 3779 35 31 4 8 0 8 0 mcl64k 65536 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 417 0 0 39 2 37 39 0 8 0 mtagpl 96 19 0 0 1 0 1 1 0 8 0 mbufpl 256 1172 0 0 62 0 62 62 0 8 0 bufpl 280 11205 0 3111 579 0 579 579 0 8 0 anonpl 24 447994 0 441869 187 106 81 94 0 186 12 amapchunkpl 152 66621 0 65939 95 56 39 49 0 158 9 amappl16 200 10095 0 9960 96 76 20 20 0 8 7 amappl15 192 51 0 50 1 0 1 1 0 8 0 amappl14 184 241 0 229 2 1 1 2 0 8 0 amappl13 176 11 0 11 1 1 0 1 0 8 0 amappl12 168 3346 0 3317 2 0 2 2 0 8 0 amappl11 160 51 0 41 1 0 1 1 0 8 0 amappl10 152 63 0 52 1 0 1 1 0 8 0 amappl9 144 189 0 187 1 0 1 1 0 8 0 amappl8 136 213 0 173 2 0 2 2 0 8 0 amappl7 128 65 0 50 1 0 1 1 0 8 0 amappl6 120 622 0 609 2 1 1 2 0 8 0 amappl5 112 264 0 252 1 0 1 1 0 8 0 amappl4 104 723 0 689 2 0 2 2 0 8 0 amappl3 96 12485 0 12404 3 0 3 3 0 8 0 amappl2 88 2778 0 2709 3 1 2 3 0 8 0 amappl1 80 17098 0 16609 22 10 12 22 0 8 0 amappl 88 18950 0 18749 6 0 6 6 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 97 0 3 2 0 2 2 0 8 0 uaddrrnd 24 2341 0 2306 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2341 0 2306 1 0 1 1 0 8 0 vmmpekpl 168 21133 0 21075 3 0 3 3 0 8 0 vmmpepl 168 163410 0 161540 194 89 105 112 0 357 10 vmsppl 440 2340 0 2306 6 1 5 5 0 8 0 rwobjpl 56 49997 0 43136 115 14 101 101 0 8 0 pdppl 4096 4689 0 4620 229 152 77 79 0 8 8 pvpl 32 44994 0 0 363 0 363 363 0 265 0 pmappl 248 2340 0 2306 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 621 0 208 12 0 12 12 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x1e: addq $0x8,%rsp x86_ipi_db(ffffffff82cb2ff0) at x86_ipi_db+0x1e 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+0x27 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x1a kd_curproc sys/dev/kcov.c:585 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x1a sys/dev/kcov.c:158 __mp_lock(ffffffff82e29c08) at __mp_lock+0x133 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82e29c08) at __mp_lock+0x133 sys/kern/kern_lock.c:147 intr_handler(ffff80002a285810,ffff80000067b200) at intr_handler+0x62 sys/arch/amd64/amd64/intr.c:539 Xintr_ioapic_edge25_untramp() at Xintr_ioapic_edge25_untramp+0x18f Xspllower() at Xspllower+0x1d cnputc(6e) at cnputc+0x4f sys/dev/cons.c:218 db_putchar(6e) at db_putchar+0x3eb sys/ddb/db_output.c:155 kprintf() at kprintf+0x21c1 sys/kern/subr_prf.c:1064 db_printf(ffffffff828fb1d3) at db_printf+0x89 sys/kern/subr_prf.c:498 panic(ffffffff82892ca5) at panic+0xdb sys/kern/subr_prf.c:216 vop_generic_badop(ffff80002a285c38) at vop_generic_badop+0x1f sys/kern/vfs_default.c:133 end trace frame: 0xffff80002a285c80, count: 0 ddb{0}> trace x86_ipi_db(ffffffff82cb2ff0) at x86_ipi_db+0x1e 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+0x27 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x1a kd_curproc sys/dev/kcov.c:585 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x1a sys/dev/kcov.c:158 __mp_lock(ffffffff82e29c08) at __mp_lock+0x133 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82e29c08) at __mp_lock+0x133 sys/kern/kern_lock.c:147 intr_handler(ffff80002a285810,ffff80000067b200) at intr_handler+0x62 sys/arch/amd64/amd64/intr.c:539 Xintr_ioapic_edge25_untramp() at Xintr_ioapic_edge25_untramp+0x18f Xspllower() at Xspllower+0x1d cnputc(6e) at cnputc+0x4f sys/dev/cons.c:218 db_putchar(6e) at db_putchar+0x3eb sys/ddb/db_output.c:155 kprintf() at kprintf+0x21c1 sys/kern/subr_prf.c:1064 db_printf(ffffffff828fb1d3) at db_printf+0x89 sys/kern/subr_prf.c:498 panic(ffffffff82892ca5) at panic+0xdb sys/kern/subr_prf.c:216 vop_generic_badop(ffff80002a285c38) at vop_generic_badop+0x1f sys/kern/vfs_default.c:133 VOP_STRATEGY(fffffd80583b3600,fffffd80622416a0) at VOP_STRATEGY+0x9f sys/kern/vfs_vops.c:628 bwrite(fffffd80622416a0) at bwrite+0x1d3 sys/kern/vfs_bio.c:757 VOP_BWRITE(fffffd80622416a0) at VOP_BWRITE+0x4e sys/kern/vfs_vops.c:640 ufs_mkdir(ffff80002a285eb0) at ufs_mkdir+0x445 sys/ufs/ufs/ufs_vnops.c:1165 VOP_MKDIR(fffffd805c2ba880,ffff80002a286010,ffff80002a286040,ffff80002a285f40) at VOP_MKDIR+0xc3 sys/kern/vfs_vops.c:388 domkdirat(ffff8000ffff7728,ffffff9c,20000280,0) at domkdirat+0x125 sys/kern/vfs_syscalls.c:3077 syscall(ffff80002a2861c0) at syscall+0x854 mi_syscall sys/sys/syscall_mi.h:180 [inline] syscall(ffff80002a2861c0) at syscall+0x854 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x9e69a343b20, count: -22 ddb{0}> machine ddbcpu 1 Stopped at savectx+0xae: movl $0,%gs:0x680 savectx() at savectx+0xae end of kernel end trace frame: 0x2f19c3d10, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x2f19c3d10, count: -1