witness: lock order reversal: 1st 0xffffffff82cfb918 &sched_lock (&sched_lock) 2nd 0xffff80002126ef38 &pr->ps_mtx (&pr->ps_mtx) lock order "&pr->ps_mtx"(mutex) -> "&sched_lock"(sched_lock) first seen at: #0 __mp_lock+0xa2 read_rflags machine/cpufunc.h:195 [inline] #0 __mp_lock+0xa2 intr_disable machine/cpufunc.h:216 [inline] #0 __mp_lock+0xa2 sys/kern/kern_lock.c:142 #1 donice+0x178 sys/kern/kern_resource.c:218 #2 syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] #2 syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 #3 Xsyscall+0x128 lock order "&sched_lock"(sched_lock) -> "&pr->ps_mtx"(mutex) first seen at: #0 mtx_enter+0x3e sys/kern/kern_lock.c:265 #1 single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] #1 single_thread_set+0x35a sys/kern/kern_sig.c:2155 #2 sigexit+0x90 sys/kern/kern_sig.c:1562 #3 postsig+0x4a9 sys/kern/kern_sig.c:1494 #4 userret+0x16e sys/kern/kern_sig.c:1987 #5 syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] #5 syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 #6 Xsyscall+0x128 Stopped at db_enter+0x1c: addq $0x8,%rsp ddb{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic the kernel did not panic ddb{0}> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(ffff80002126ef38,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff80002126ef38,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff80002126ef28) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff80002124a2a8,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff80002124a2a8,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff80002124a2a8,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff80002124a2a8,6,ffff8000212877d8) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff80002124a2a8) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff800021287910) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff800021287910) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xac3ec8067b0, count: -9 ddb{0}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be63 rbp 0xffff8000212874e0 rbx 0x3 rdx 0xffff800000d27380 rcx 0xffff80002124a2a8 rax 0x3ffff acpi_pdirpa+0x2be62 r8 0xffff800021287450 r9 0x8080808080808080 r10 0x8d04f9c75d886798 r11 0xa717a779a6ffc377 r12 0xfffffd8003a0e850 r13 0 r14 0xfffffd80039fbbe0 r15 0xfffffd80031cbbc0 rip 0xffffffff810eab1c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff8000212874d0 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.3) pid=355278 stat=onproc flags process=500000 proc=4002000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff80002124aaa0,0xffff80002129f808 process=0xffff80002126ee28 user=0xffff800021282000, vmspace=0xfffffd80698f7018 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 82286 261589 77668 0 2 0 syz-executor.7 82286 147551 77668 0 3 0x4000080 kqread syz-executor.7 7640 189892 69820 0 2 0 syz-executor.6 7640 94647 69820 0 3 0x4000080 fsleep syz-executor.6 99070 326241 40947 0 4 0x582000 syz-executor.3 *99070 355278 40947 0 7 0x4502000 syz-executor.3 99070 36889 40947 0 4 0x4580080 fsleep syz-executor.3 62642 202316 9973 0 3 0x82 piperd syz-executor.2 40947 415654 9973 0 3 0x82 nanoslp syz-executor.3 77668 124331 9973 0 3 0x82 nanoslp syz-executor.7 81630 77347 9973 0 3 0x82 piperd syz-executor.0 26782 86446 9973 0 3 0x82 piperd syz-executor.1 75058 277696 9973 0 3 0x82 nanoslp syz-executor.4 83629 126821 0 0 3 0x14200 acct acct 87132 500895 0 0 3 0x14200 bored sosplice 69820 107694 9973 0 3 0x82 nanoslp syz-executor.6 41781 148871 9973 0 3 0x2 biowait syz-executor.5 9973 44981 20330 0 3 0x2000082 wait syz-fuzzer 9973 476310 20330 0 3 0x6000082 nanoslp syz-fuzzer 9973 355613 20330 0 3 0x6000082 wait syz-fuzzer 9973 233942 20330 0 3 0x6000082 wait syz-fuzzer 9973 11269 20330 0 3 0x6000082 kqread syz-fuzzer 9973 415001 20330 0 3 0x6000082 thrsleep syz-fuzzer 9973 448863 20330 0 3 0x6000082 thrsleep syz-fuzzer 9973 196626 20330 0 3 0x6000082 wait syz-fuzzer 9973 422532 20330 0 3 0x6000082 thrsleep syz-fuzzer 9973 186723 20330 0 3 0x6000082 thrsleep syz-fuzzer 9973 240622 20330 0 3 0x6000082 wait syz-fuzzer 9973 40686 20330 0 3 0x6000082 wait syz-fuzzer 9973 262236 20330 0 3 0x6000082 thrsleep syz-fuzzer 9973 216554 20330 0 3 0x6000082 wait syz-fuzzer 9973 359383 20330 0 3 0x6000082 wait syz-fuzzer 9973 59403 20330 0 3 0x6000082 thrsleep syz-fuzzer 20330 273016 92219 0 3 0x10008a sigsusp ksh 92219 290241 53012 0 3 0x9a kqread sshd 53505 461025 1 0 3 0x100083 ttyin getty 53012 139407 1 0 3 0x88 kqread sshd 75674 475754 52398 74 3 0x1100092 bpf pflogd 52398 488444 1 0 3 0x80 netio pflogd 68446 135486 98801 73 3 0x1100090 kqread syslogd 98801 510943 1 0 3 0x100082 netio syslogd 4082 184810 1 0 3 0x100080 kqread resolvd 58694 372733 18772 77 3 0x100092 kqread dhcpleased 67953 263418 18772 77 3 0x100092 kqread dhcpleased 18772 436883 1 0 3 0x80 kqread dhcpleased 67955 200215 0 0 3 0x14200 bored smr 17783 229577 0 0 7 0x14200 zerothread 68975 202964 0 0 3 0x14200 aiodoned aiodoned 66029 247814 0 0 3 0x14200 syncer update 46955 405000 0 0 3 0x14200 cleaner cleaner 60257 355664 0 0 3 0x14200 reaper reaper 19066 152081 0 0 3 0x14200 pgdaemon pagedaemon 61425 334928 0 0 3 0x14200 bored viomb 24270 505969 0 0 3 0x40014200 acpi0 acpi0 12574 94442 0 0 3 0x40014200 idle1 47489 275196 0 0 3 0x14200 bored softnet3 67109 192573 0 0 3 0x14200 bored softnet2 98835 479975 0 0 3 0x14200 bored softnet1 89172 270005 0 0 3 0x14200 bored softnet0 99303 402409 0 0 3 0x14200 bored systqmp 98711 14750 0 0 3 0x14200 bored systq 69856 251575 0 0 3 0x40014200 bored softclock 20290 75654 0 0 3 0x40014200 idle0 1 507102 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 0: exclusive sched_lock &sched_lock r = 0 (0xffffffff82cfb918) #0 witness_lock+0x447 #1 single_thread_set+0x179 sys/kern/kern_sig.c:2113 #2 sigexit+0x90 sys/kern/kern_sig.c:1562 #3 postsig+0x4a9 sys/kern/kern_sig.c:1494 #4 userret+0x16e sys/kern/kern_sig.c:1987 #5 syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] #5 syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 #6 Xsyscall+0x128 Process 99070 (syz-executor.3) thread 0xffff80002124a2a8 (355278) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82c82c68) #0 witness_lock+0x447 #1 postsig+0x49e sys/kern/kern_sig.c:1500 #2 userret+0x16e sys/kern/kern_sig.c:1987 #3 syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] #3 syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 #4 Xsyscall+0x128 exclusive sched_lock &sched_lock r = 0 (0xffffffff82cfb918) #0 witness_lock+0x447 #1 single_thread_set+0x179 sys/kern/kern_sig.c:2113 #2 sigexit+0x90 sys/kern/kern_sig.c:1562 #3 postsig+0x4a9 sys/kern/kern_sig.c:1494 #4 userret+0x16e sys/kern/kern_sig.c:1987 #5 syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] #5 syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 #6 Xsyscall+0x128 Process 41781 (syz-executor.5) thread 0xffff80002124b7e8 (148871) exclusive rrwlock inode r = 0 (0xfffffd8064f51708) #0 witness_lock+0x447 #1 rw_enter+0x3c8 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x8c sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0x8b sys/kern/vfs_vops.c:518 #4 ufs_ihashins+0x46 sys/ufs/ufs/ufs_ihash.c:140 #5 ffs_vget+0x141 sys/ufs/ffs/ffs_vfsops.c:1343 #6 ffs_inode_alloc+0x1c2 sys/ufs/ffs/ffs_alloc.c:394 #7 ufs_mkdir+0xf8 sys/ufs/ufs/ufs_vnops.c:1149 #8 VOP_MKDIR+0xc3 sys/kern/vfs_vops.c:388 #9 domkdirat+0x125 sys/kern/vfs_syscalls.c:3073 #10 syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] #10 syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 #11 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806b8361b8) #0 witness_lock+0x447 #1 rw_enter+0x3c8 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x8c sys/kern/kern_rwlock.c:464 #3 VOP_LOCK+0x8b sys/kern/vfs_vops.c:518 #4 vn_lock+0x84 sys/kern/vfs_vnops.c:564 #5 vfs_lookup+0xd5 sys/kern/vfs_lookup.c:418 #6 namei+0x55a sys/kern/vfs_lookup.c:250 #7 domkdirat+0x79 sys/kern/vfs_syscalls.c:3058 #8 syscall+0x5e2 mi_syscall sys/sys/syscall_mi.h:110 [inline] #8 syscall+0x5e2 sys/arch/amd64/amd64/trap.c:623 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10195 6489K 10779K 78643K 18453 0 pcb 13 12K 13K 78643K 196 0 rtable 237 7K 7K 78643K 738 0 pf 32 9K 10K 78643K 123 0 ifaddr 45 15K 16K 78643K 120 0 ifgroup 55 2K 2K 78643K 193 0 sysctl 2 0K 0K 78643K 2 0 counters 60 35K 36K 78643K 132 0 ioctlops 0 0K 4K 78643K 1561 0 iov 0 0K 16K 78643K 212 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1537 96K 96K 78643K 4419 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 51 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 842 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 13 45K 89K 78643K 4550 0 sigio 0 0K 0K 78643K 16 0 proc 69 91K 128K 78643K 1088 0 subproc 104 6K 6K 78643K 249 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 194 0 in_multi 99 7K 7K 78643K 257 0 ether_multi 1 0K 0K 78643K 2 0 mrt 1 0K 0K 78643K 2 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 61 281K 281K 78643K 61 0 exec 0 0K 1K 78643K 1054 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 8 62K 64K 78643K 10 0 UVM amap 358 88K 102K 78643K 47863 0 UVM aobj 131 4K 4K 78643K 131 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 84 0 NDP 12 0K 1K 78643K 86 0 temp 77 5916K 5988K 78643K 316483 0 kqueue 12 18K 33K 78643K 1038 0 SYN cache 2 16K 24K 78643K 3 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 120 133 0 130 1 0 1 1 0 8 0 rtentry 112 239 0 129 4 0 4 4 0 8 0 unpcb 144 4160 0 4141 46 40 6 6 0 8 5 syncache 304 26 0 26 5 4 1 1 0 8 1 tcpqe 32 147 0 147 4 3 1 1 0 8 1 tcpcb 808 705 0 697 30 29 1 14 0 8 0 arp 120 41 0 23 1 0 1 1 0 8 0 inpcb 368 1665 0 1655 42 38 4 13 0 8 2 nd6 136 63 0 39 1 0 1 1 0 8 0 pkpcb 40 10 0 10 1 1 0 1 0 8 0 kcovpl 48 19 0 11 1 0 1 1 0 8 0 ppxss 1256 7 0 7 3 2 1 1 0 8 1 pffrag 232 35 0 32 1 0 1 1 0 482 0 pffrnode 88 35 0 32 1 0 1 1 0 8 0 pffrent 40 144 0 141 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 24 144 0 123 1 0 1 1 0 8 0 pfstkey 128 144 0 123 3 1 2 2 0 8 0 pfstate 376 144 0 123 6 2 4 4 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 256 981 0 524 30 1 29 30 0 8 0 art_table 32 982 0 524 4 0 4 4 0 8 0 art_node 16 238 0 138 1 0 1 1 0 8 0 sysvmsgpl 40 10 0 0 1 0 1 1 0 8 0 semapl 112 840 0 830 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 7513 0 5751 111 0 111 111 0 8 0 ffsino 272 7513 0 5751 118 0 118 118 0 8 0 nchpl 144 14517 0 12857 64 0 64 64 0 8 0 uvmvnodes 80 7716 0 0 158 0 158 158 0 8 0 vnodes 216 7716 0 0 429 0 429 429 0 8 0 namei 1024 51508 0 51507 3 2 1 3 0 8 0 percpumem 16 79 0 36 1 0 1 1 0 8 0 vmpool 696 44 0 44 3 3 0 1 0 8 0 kstatmem 264 96 0 72 2 0 2 2 0 8 0 scxspl 216 49713 0 49712 26 25 1 8 1 8 0 plimitpl 152 404 0 388 1 0 1 1 0 8 0 sigapl 424 4853 0 4807 8 2 6 7 0 8 0 futexpl 64 35612 0 35610 1 0 1 1 0 8 0 knotepl 120 369 0 0 11 0 11 11 0 8 0 kqueuepl 216 1172 0 1163 16 15 1 12 0 8 0 pipepl 320 667 0 639 20 17 3 8 0 8 0 fdescpl 496 4834 0 4808 6 2 4 5 0 8 0 filepl 152 29921 0 29674 55 40 15 19 0 8 5 lockfpl 104 1363 0 1360 3 1 2 2 0 8 1 lockfspl 48 613 0 610 1 0 1 1 0 8 0 sessionpl 144 35 0 18 1 0 1 1 0 8 0 pgrppl 48 52 0 35 1 0 1 1 0 8 0 ucredpl 104 2754 0 2741 1 0 1 1 0 8 0 zombiepl 144 4808 0 4807 1 0 1 1 0 8 0 processpl 1072 4853 0 4807 4 0 4 4 0 8 0 procpl 680 13046 0 12981 12 4 8 8 0 8 1 sosppl 168 46 0 45 7 6 1 1 0 8 0 sockpl 488 5968 0 5935 151 139 12 21 0 8 7 mcl64k 65536 17 0 0 3 0 3 3 0 8 0 mcl16k 16384 30 0 0 4 2 2 3 0 8 0 mcl12k 12288 25 0 0 2 0 2 2 0 8 0 mcl9k 9216 8 0 0 1 0 1 1 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 0 8 0 mcl4k 4096 33 0 0 4 1 3 3 0 8 0 mcl2k2 2112 7 0 0 1 0 1 1 0 8 0 mcl2k 2048 258 0 0 31 6 25 31 0 8 0 mtagpl 96 267 0 0 7 0 7 7 0 8 0 mbufpl 256 1204 0 0 66 0 66 66 0 8 0 bufpl 288 16578 0 8852 552 0 552 552 0 8 0 anonpl 24 564838 0 551513 126 30 96 112 0 186 0 amapchunkpl 152 151203 0 150397 77 39 38 48 0 158 1 amappl16 200 11571 0 11147 47 23 24 36 0 8 0 amappl15 192 10 0 10 1 1 0 1 0 8 0 amappl14 184 202 0 184 2 1 1 2 0 8 0 amappl13 176 16 0 14 2 1 1 1 0 8 0 amappl12 168 5672 0 5646 3 1 2 2 0 8 0 amappl11 160 130 0 114 1 0 1 1 0 8 0 amappl10 152 64 0 51 1 0 1 1 0 8 0 amappl9 144 215 0 213 1 0 1 1 0 8 0 amappl8 136 363 0 275 4 0 4 4 0 8 0 amappl7 128 85 0 71 1 0 1 1 0 8 0 amappl6 120 330 0 310 2 1 1 2 0 8 0 amappl5 112 306 0 294 1 0 1 1 0 8 0 amappl4 104 737 0 690 4 2 2 3 0 8 0 amappl3 96 29509 0 29437 4 1 3 3 0 8 0 amappl2 88 5207 0 5142 3 1 2 3 0 8 0 amappl1 80 26115 0 25565 24 11 13 23 0 8 0 amappl 88 47081 0 46859 9 2 7 7 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 72 130 0 0 3 0 3 3 0 8 0 uaddrrnd 24 4878 0 4852 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4878 0 4852 1 0 1 1 0 8 0 vmmpekpl 168 40008 0 39947 4 0 4 4 0 8 0 vmmpepl 168 306193 0 303952 167 53 114 127 0 357 0 vmsppl 464 4877 0 4852 6 2 4 5 0 8 0 rwobjpl 56 86599 0 77219 141 8 133 133 0 8 0 pdppl 4096 9764 0 9704 256 186 70 82 0 8 10 pvpl 32 1509802 0 1490526 414 239 175 368 0 265 0 pmappl 248 4877 0 4852 4 2 2 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1275 0 273 29 0 29 29 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(ffff80002126ef38,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff80002126ef38,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff80002126ef28) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff80002124a2a8,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff80002124a2a8,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff80002124a2a8,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff80002124a2a8,6,ffff8000212877d8) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff80002124a2a8) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff800021287910) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff800021287910) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xac3ec8067b0, count: -9 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1e: addq $0x8,%rsp ddb{1}> trace x86_ipi_db(ffff800020d58ff0) 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 __mp_lock(ffffffff82cfb710) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82cfb710) at __mp_lock+0x122 sys/kern/kern_lock.c:147 yield() at yield+0x37 sys/kern/sched_bsd.c:321 uvm_pagezero_thread(ffff8000211b22b0) at uvm_pagezero_thread+0x6d sys/uvm/uvm_pmemrange.c:2170 end trace frame: 0x0, count: -6