witness: lock order reversal: 1st 0xffffffff82cc8bd0 &sched_lock (&sched_lock) 2nd 0xffff8000ffffa6c8 &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{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic the kernel did not panic ddb{1}> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(ffff8000ffffa6c8,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff8000ffffa6c8,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff8000ffffa6b8) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff80002121b010,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff80002121b010,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff80002121b010,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff80002121b010,6,ffff800023b3f8f8) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff80002121b010) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff800023b3fa30) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff800023b3fa30) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xc4c3c437b90, count: -9 ddb{1}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be63 rbp 0xffff800023b3f600 rbx 0x3 rdx 0xffff800000cf9400 rcx 0xffff80002121b010 rax 0x3ffff acpi_pdirpa+0x2be62 r8 0xffff800023b3f570 r9 0x8080808080808080 r10 0xd305b6102b2e2ba6 r11 0xbdd7258c33a10afe r12 0xfffffd8003a0a4e0 r13 0 r14 0xfffffd80039f79d0 r15 0xfffffd80031c7bc0 rip 0xffffffff81b6e27c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff800023b3f5f0 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=489981 stat=onproc flags process=500010 proc=4002000 pri=32, usrpri=79, nice=20 forw=0xffffffffffffffff, list=0xffff80002121aac0,0xffffffff82c90e98 process=0xffff8000ffffa5b8 user=0xffff800023b3a000, vmspace=0xfffffd806442cb08 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 88296 159618 74097 32767 4 0x582010 syz-executor.0 *88296 489981 74097 32767 7 0x4502010 syz-executor.0 79571 131377 89971 32767 2 0x10 syz-executor.6 62058 197592 52687 32767 2 0x10 syz-executor.3 62058 59195 52687 32767 3 0x4000090 fsleep syz-executor.3 62058 177921 52687 32767 3 0x4000090 fsleep syz-executor.3 62058 64214 52687 32767 2 0x4000010 syz-executor.3 46414 242647 51371 32767 2 0x10 syz-executor.2 46414 403935 51371 32767 3 0x4000090 kqread syz-executor.2 15357 234528 22631 32767 2 0x10 syz-executor.7 15357 509725 22631 32767 3 0x4000090 fsleep syz-executor.7 15357 498799 22631 32767 3 0x4000090 fsleep syz-executor.7 15357 209932 22631 32767 3 0x4000090 fsleep syz-executor.7 9074 357660 94577 32767 2 0x10 syz-executor.4 9074 95666 94577 32767 3 0x4000090 fsleep syz-executor.4 9074 57507 94577 32767 3 0x4000090 fsleep syz-executor.4 51371 473344 72215 32767 3 0x90 nanoslp syz-executor.2 72215 329471 8275 0 3 0x82 wait syz-executor.2 22631 335453 27745 32767 3 0x90 nanoslp syz-executor.7 27745 346951 8275 0 3 0x82 wait syz-executor.7 94577 521349 90871 32767 3 0x90 nanoslp syz-executor.4 90871 198698 8275 0 3 0x82 wait syz-executor.4 74097 445826 98715 32767 3 0x90 nanoslp syz-executor.0 98715 187435 8275 0 3 0x82 wait syz-executor.0 72057 74370 24787 32767 7 0x10 syz-executor.1 24787 298384 8275 0 3 0x82 wait syz-executor.1 76710 278147 0 0 3 0x14200 bored sosplice 89971 237556 5378 32767 3 0x90 nanoslp syz-executor.6 5378 432174 8275 0 3 0x82 wait syz-executor.6 52687 145242 68407 32767 2 0x10 syz-executor.3 66458 257808 35708 32767 3 0x10 biowait syz-executor.5 35708 437094 8275 0 3 0x82 wait syz-executor.5 68407 343116 8275 0 3 0x82 wait syz-executor.3 8275 246429 66820 0 3 0x2000082 wait syz-fuzzer 8275 396750 66820 0 3 0x6000082 nanoslp syz-fuzzer 8275 401603 66820 0 3 0x6000082 thrsleep syz-fuzzer 8275 411292 66820 0 3 0x6000082 wait syz-fuzzer 8275 239973 66820 0 3 0x6000082 thrsleep syz-fuzzer 8275 340913 66820 0 3 0x6000082 wait syz-fuzzer 8275 356949 66820 0 3 0x6000082 thrsleep syz-fuzzer 8275 61391 66820 0 3 0x6000082 wait syz-fuzzer 8275 412688 66820 0 3 0x6000082 thrsleep syz-fuzzer 8275 115223 66820 0 3 0x6000082 thrsleep syz-fuzzer 8275 31200 66820 0 3 0x6000082 wait syz-fuzzer 8275 323500 66820 0 3 0x6000082 wait syz-fuzzer 8275 509718 66820 0 3 0x6000082 wait syz-fuzzer 8275 146373 66820 0 3 0x6000082 wait syz-fuzzer 8275 481426 66820 0 3 0x6000082 thrsleep syz-fuzzer 8275 370704 66820 0 3 0x6000082 kqread syz-fuzzer 66820 518889 99473 0 3 0x10008a sigsusp ksh 99473 195906 94720 0 3 0x9a kqread sshd 50033 265336 1 0 3 0x100083 ttyin getty 94720 90272 1 0 3 0x88 kqread sshd 23419 128866 84588 73 3 0x1100090 kqread syslogd 84588 195194 1 0 3 0x100082 netio syslogd 62730 1009 1 0 3 0x100080 kqread resolvd 5663 288978 94302 77 3 0x100092 kqread dhcpleased 42660 518888 94302 77 3 0x100092 kqread dhcpleased 94302 389506 1 0 3 0x80 kqread dhcpleased 19621 470588 0 0 3 0x14200 bored smr 82416 367809 0 0 2 0x14200 zerothread 14894 91822 0 0 3 0x14200 aiodoned aiodoned 67820 32181 0 0 3 0x14200 syncer update 89454 97665 0 0 3 0x14200 cleaner cleaner 56078 329968 0 0 3 0x14200 reaper reaper 7913 443970 0 0 3 0x14200 pgdaemon pagedaemon 63219 10177 0 0 3 0x14200 bored viomb 60360 87029 0 0 3 0x40014200 acpi0 acpi0 72229 519362 0 0 3 0x40014200 idle1 63197 63067 0 0 3 0x14200 bored softnet3 24564 302565 0 0 3 0x14200 bored softnet2 77959 257883 0 0 3 0x14200 bored softnet1 30964 233133 0 0 3 0x14200 bored softnet0 39337 408486 0 0 3 0x14200 bored systqmp 323 463952 0 0 3 0x14200 bored systq 76489 249699 0 0 3 0x40014200 bored softclock 75889 98665 0 0 3 0x40014200 idle0 1 373347 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 1: exclusive sched_lock &sched_lock r = 0 (0xffffffff82cc8bd0) #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 88296 (syz-executor.0) thread 0xffff80002121b010 (489981) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82ca0228) #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 (0xffffffff82cc8bd0) #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 66458 (syz-executor.5) thread 0xffff80002121bd58 (257808) exclusive rrwlock inode r = 0 (0xfffffd8067bb2700) #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 (0xfffffd8067bb2c50) #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{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10188 6408K 6420K 78643K 11314 0 pcb 13 12K 14K 78643K 17 0 rtable 238 6K 7K 78643K 1560 0 pf 29 8K 8K 78643K 61 0 ifaddr 44 15K 15K 78643K 112 0 ifgroup 50 2K 2K 78643K 114 0 sysctl 2 0K 0K 78643K 2 0 counters 60 35K 35K 78643K 92 0 ioctlops 0 0K 2K 78643K 80 0 iov 0 0K 18K 78643K 6814 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1279 80K 80K 78643K 2128 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 3 5K 9K 78643K 111 0 VM map 2 1K 1K 78643K 2 0 sem 10 1K 1K 78643K 14 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 24 89K 121K 78643K 7130 0 sigio 0 0K 0K 78643K 101 0 proc 56 78K 115K 78643K 1263 0 subproc 104 6K 6K 78643K 312 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 567 0 in_multi 99 7K 7K 78643K 329 0 ether_multi 1 0K 0K 78643K 7 0 mrt 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 67 307K 307K 78643K 67 0 exec 0 0K 1K 78643K 1623 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 449 92K 105K 78643K 71800 0 UVM aobj 131 4K 4K 78643K 134 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 1 0K 0K 78643K 237 0 NDP 11 0K 2K 78643K 75 0 temp 74 5920K 6048K 78643K 22572 0 kqueue 13 20K 32K 78643K 632 0 SYN cache 2 16K 16K 78643K 2 0 ddb{1}> 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 1023 0 1018 14 13 1 5 0 8 0 rtentry 112 299 0 187 4 0 4 4 0 8 0 unpcb 144 3391 0 3378 42 36 6 6 0 8 5 syncache 304 104 0 104 13 12 1 1 0 8 1 tcpqe 32 730 0 730 15 14 1 2 0 8 1 tcpcb 808 3014 0 2985 74 64 10 15 0 8 6 arp 120 53 0 34 1 0 1 1 0 8 0 ipq 40 12 0 10 3 2 1 1 0 8 0 ipqe 40 45 0 43 3 2 1 1 0 8 0 inpcb 368 12000 0 11958 106 96 10 20 0 8 4 nd6 136 81 0 56 1 0 1 1 0 8 0 kcovpl 48 24 0 16 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1199 0 736 31 1 30 30 0 8 0 art_table 32 1200 0 736 4 0 4 4 0 8 0 art_node 16 298 0 196 1 0 1 1 0 8 0 sysvmsgpl 40 15 0 0 1 0 1 1 0 8 0 semupl 112 6 0 6 1 1 0 1 0 8 0 semapl 112 8 0 0 1 0 1 1 0 8 0 shmpl 112 131 0 3 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 9865 0 8418 91 0 91 91 0 8 0 ffsino 272 9865 0 8418 97 0 97 97 0 8 0 nchpl 144 18844 0 17202 63 0 63 63 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 61765 0 61764 2 1 1 2 0 8 0 percpumem 16 59 0 16 1 0 1 1 0 8 0 kstatmem 264 54 0 32 2 0 2 2 0 8 0 scxspl 216 56988 0 56987 27 26 1 8 1 8 0 plimitpl 152 975 0 952 10 8 2 2 0 8 1 sigapl 424 7392 0 7339 7 0 7 7 0 8 0 futexpl 64 67953 0 67946 1 0 1 1 0 8 0 knotepl 120 751 0 0 18 1 17 17 0 8 0 kqueuepl 216 1688 0 1679 35 34 1 5 0 8 0 pipepl 320 1667 0 1639 48 45 3 8 0 8 0 fdescpl 496 7374 0 7339 7 1 6 6 0 8 0 filepl 152 44813 0 44573 71 56 15 19 0 8 5 lockfpl 104 1230 0 1228 2 1 1 2 0 8 0 lockfspl 48 369 0 367 1 0 1 1 0 8 0 sessionpl 144 39 0 23 1 0 1 1 0 8 0 pgrppl 48 110 0 94 1 0 1 1 0 8 0 ucredpl 104 4473 0 4455 1 0 1 1 0 8 0 zombiepl 144 7339 0 7339 1 0 1 1 0 8 1 processpl 1072 7392 0 7339 5 1 4 5 0 8 0 procpl 680 19960 0 19882 19 11 8 8 0 8 1 sosppl 168 76 0 73 5 4 1 1 0 8 0 sockpl 488 16902 0 16848 225 210 15 30 0 8 8 mcl64k 65536 41 0 0 4 1 3 3 0 8 0 mcl16k 16384 26 0 0 4 1 3 3 0 8 0 mcl12k 12288 25 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 33 0 0 3 0 3 3 0 8 0 mcl4k 4096 47 0 0 3 0 3 3 0 8 0 mcl2k2 2112 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 350 0 0 33 1 32 33 0 8 2 mtagpl 96 4 0 0 1 0 1 1 0 8 0 mbufpl 256 3452 0 0 211 0 211 211 0 8 0 bufpl 288 13964 0 7636 453 0 453 453 0 8 0 anonpl 24 827935 0 816550 184 99 85 99 0 186 0 amapchunkpl 152 233198 0 232306 85 39 46 49 0 158 9 amappl16 200 17703 0 17401 108 90 18 29 0 8 0 amappl15 192 11 0 11 1 1 0 1 0 8 0 amappl14 184 219 0 202 2 1 1 2 0 8 0 amappl13 176 28 0 28 7 6 1 1 0 8 1 amappl12 168 8243 0 8207 2 0 2 2 0 8 0 amappl11 160 53 0 42 1 0 1 1 0 8 0 amappl10 152 50 0 38 1 0 1 1 0 8 0 amappl9 144 1013 0 1013 5 4 1 1 0 8 1 amappl8 136 803 0 621 7 0 7 7 0 8 0 amappl7 128 157 0 142 2 0 2 2 0 8 0 amappl6 120 960 0 938 2 1 1 2 0 8 0 amappl5 112 463 0 453 1 0 1 1 0 8 0 amappl4 104 781 0 736 3 1 2 3 0 8 0 amappl3 96 44714 0 44621 5 2 3 4 0 8 0 amappl2 88 7947 0 7869 3 1 2 3 0 8 0 amappl1 80 34294 0 33762 22 9 13 22 0 8 0 amappl 88 70893 0 70627 7 0 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 72 133 0 3 3 0 3 3 0 8 0 uaddrrnd 24 7374 0 7339 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 7374 0 7339 1 0 1 1 0 8 0 vmmpekpl 168 58866 0 58783 5 0 5 5 0 8 0 vmmpepl 168 447710 0 445193 199 78 121 129 0 357 3 vmsppl 464 7373 0 7339 7 2 5 6 0 8 0 rwobjpl 56 120264 0 112760 117 8 109 110 0 8 0 pdppl 4096 14756 0 14678 344 262 82 94 0 8 4 pvpl 32 2191318 0 2173705 442 275 167 363 0 265 5 pmappl 248 7373 0 7339 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1482 0 440 31 0 31 31 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x1e: addq $0x8,%rsp ddb{0}> trace x86_ipi_db(ffffffff82c05ff0) 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(ffffffff82ca0020) at __mp_lock+0x12e __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82ca0020) at __mp_lock+0x12e sys/kern/kern_lock.c:147 intr_handler(ffff8000212c8e30,ffff800000069c00) at intr_handler+0x62 sys/arch/amd64/amd64/intr.c:532 Xintr_ioapic_edge16_untramp() at Xintr_ioapic_edge16_untramp+0x18f __mp_lock(ffffffff82ca0020) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82ca0020) at __mp_lock+0x122 sys/kern/kern_lock.c:147 intr_handler(ffff8000212c8f80,ffff80000006bc00) at intr_handler+0x62 sys/arch/amd64/amd64/intr.c:532 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x29 kd_curproc sys/dev/kcov.c:589 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x29 sys/dev/kcov.c:158 __mp_lock(ffffffff82ca0020) at __mp_lock+0x133 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82ca0020) at __mp_lock+0x133 sys/kern/kern_lock.c:147 syscall(ffff8000212c9160) at syscall+0x5cd mi_syscall sys/sys/syscall_mi.h:110 [inline] syscall(ffff8000212c9160) at syscall+0x5cd sys/arch/amd64/amd64/trap.c:623 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7516962ee9f0, count: -13 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x1c: addq $0x8,%rsp ddb{1}> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 witness_checkorder(ffff8000ffffa6c8,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff8000ffffa6c8,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff8000ffffa6b8) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff80002121b010,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff80002121b010,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff80002121b010,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff80002121b010,6,ffff800023b3f8f8) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff80002121b010) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff800023b3fa30) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff800023b3fa30) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xc4c3c437b90, count: -9