witness: lock order reversal: 1st 0xffffffff82cc8bd0 &sched_lock (&sched_lock) 2nd 0xffff8000ffff8548 &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(ffff8000ffff8548,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff8000ffff8548,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff8000ffff8538) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff8000212b1d40,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff8000212b1d40,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff8000212b1d40,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff8000212b1d40,6,ffff80002e464ff8) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff8000212b1d40) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff80002e465130) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff80002e465130) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe3858742cf0, count: -9 ddb{1}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be63 rbp 0xffff80002e464d00 rbx 0x3 rdx 0xffff800000d1bb40 rcx 0xffff8000212b1d40 rax 0x3ffff acpi_pdirpa+0x2be62 r8 0xffff80002e464c70 r9 0x8080808080808080 r10 0xc0fced1fb561fae0 r11 0x954c656a6c6e0e18 r12 0xfffffd8003a0a640 r13 0 r14 0xfffffd80039f7660 r15 0xfffffd80031c7bc0 rip 0xffffffff81b6e27c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff80002e464cf0 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.6) pid=216991 stat=onproc flags process=500010 proc=4002000 pri=32, usrpri=59, nice=20 forw=0xffffffffffffffff, list=0xffff8000212b0558,0xffffffff82c90e98 process=0xffff8000ffff8438 user=0xffff80002e460000, vmspace=0xfffffd806d7a0580 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 65165 239950 51724 32767 4 0x582010 syz-executor.6 *65165 216991 51724 32767 7 0x4502010 syz-executor.6 71442 427104 21550 32767 2 0x10 syz-executor.5 71442 295580 21550 32767 2 0x4000010 syz-executor.5 71442 136944 21550 32767 3 0x4000090 netio syz-executor.5 71442 142138 21550 32767 7 0x4000010 syz-executor.5 83029 46346 99523 32767 2 0x10 syz-executor.4 83029 274950 99523 32767 3 0x4000090 ttyout syz-executor.4 83029 36358 99523 32767 3 0x4000090 fsleep syz-executor.4 83029 296401 99523 32767 3 0x4000090 fsleep syz-executor.4 21550 62208 60267 32767 3 0x90 nanoslp syz-executor.5 60267 516619 48990 0 3 0x82 wait syz-executor.5 94004 28711 94475 32767 3 0x90 piperd syz-executor.3 94475 237618 48990 0 3 0x82 wait syz-executor.3 92048 374732 64175 32767 3 0x90 piperd syz-executor.1 64175 47861 48990 0 3 0x82 wait syz-executor.1 66450 356324 58337 32767 3 0x90 piperd syz-executor.2 58337 201834 48990 0 3 0x82 wait syz-executor.2 27523 9407 57599 32767 3 0x10 biowait syz-executor.7 57599 473423 48990 0 3 0x82 wait syz-executor.7 67979 325965 0 0 3 0x14200 bored sosplice 51724 189076 4225 32767 3 0x90 nanoslp syz-executor.6 4225 154573 48990 0 3 0x82 wait syz-executor.6 99523 265151 39284 32767 3 0x90 nanoslp syz-executor.4 39284 208995 48990 0 3 0x82 wait syz-executor.4 1487 364402 59868 32767 3 0x90 nanoslp syz-executor.0 59868 328606 48990 0 3 0x82 wait syz-executor.0 48990 294686 17147 0 3 0x2000082 wait syz-fuzzer 48990 355920 17147 0 3 0x6000082 nanoslp syz-fuzzer 48990 159628 17147 0 3 0x6000082 wait syz-fuzzer 48990 44343 17147 0 3 0x6000082 wait syz-fuzzer 48990 500027 17147 0 3 0x6000082 thrsleep syz-fuzzer 48990 320224 17147 0 3 0x6000082 thrsleep syz-fuzzer 48990 290913 17147 0 3 0x6000082 wait syz-fuzzer 48990 356060 17147 0 3 0x6000082 thrsleep syz-fuzzer 48990 304231 17147 0 3 0x6000082 kqread syz-fuzzer 48990 3521 17147 0 3 0x6000082 wait syz-fuzzer 48990 284811 17147 0 3 0x6000082 thrsleep syz-fuzzer 48990 276731 17147 0 2 0x6000002 syz-fuzzer 48990 272761 17147 0 3 0x6000082 wait syz-fuzzer 48990 195951 17147 0 3 0x6000082 wait syz-fuzzer 48990 335465 17147 0 3 0x6000082 wait syz-fuzzer 48990 470278 17147 0 3 0x6000082 thrsleep syz-fuzzer 17147 56639 56910 0 3 0x10008a sigsusp ksh 56910 228499 91491 0 3 0x9a kqread sshd 98193 432822 1 0 3 0x100083 ttyin getty 91491 157157 1 0 3 0x88 kqread sshd 34052 302187 64025 73 3 0x1100090 kqread syslogd 64025 443384 1 0 3 0x100082 netio syslogd 93685 172130 1 0 3 0x100080 kqread resolvd 88668 226782 25929 77 3 0x100092 kqread dhcpleased 65830 62360 25929 77 3 0x100092 kqread dhcpleased 25929 242093 1 0 3 0x80 kqread dhcpleased 12313 149737 0 0 3 0x14200 bored smr 38402 424364 0 0 2 0x14200 zerothread 2330 147989 0 0 3 0x14200 aiodoned aiodoned 58530 332527 0 0 3 0x14200 syncer update 76734 395005 0 0 3 0x14200 cleaner cleaner 10119 350995 0 0 3 0x14200 reaper reaper 17984 457927 0 0 3 0x14200 pgdaemon pagedaemon 97161 53391 0 0 3 0x14200 bored viomb 31644 20928 0 0 3 0x40014200 acpi0 acpi0 45707 206806 0 0 3 0x40014200 idle1 45614 145525 0 0 3 0x14200 bored softnet3 62787 206174 0 0 3 0x14200 bored softnet2 88981 73926 0 0 3 0x14200 bored softnet1 25898 284783 0 0 3 0x14200 bored softnet0 23349 73748 0 0 3 0x14200 bored systqmp 7593 490883 0 0 3 0x14200 bored systq 58338 19236 0 0 3 0x40014200 bored softclock 85557 387031 0 0 3 0x40014200 idle0 1 170945 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 0: exclusive mutex &uvm.fpageqlock r = 0 (0xffffffff82cc9298) #0 witness_lock+0x447 #1 mtx_enter_try+0x104 #2 mtx_enter+0x4f sys/kern/kern_lock.c:266 #3 uvm_pmr_getpages+0xeac sys/uvm/uvm_pmemrange.c:1205 #4 uvm_pagealloc+0x1a8 sys/uvm/uvm_page.c:910 #5 uvm_fault_lower+0x1ab #6 uvm_fault+0x238 #7 upageflttrap+0x86 sys/arch/amd64/amd64/trap.c:188 #8 usertrap+0x226 sys/arch/amd64/amd64/trap.c:436 #9 recall_trap+0x8 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 65165 (syz-executor.6) thread 0xffff8000212b1d40 (216991) 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 71442 (syz-executor.5) thread 0xffff8000212b17f0 (142138) exclusive rwlock amaplk r = 0 (0xfffffd80766f2088) #0 witness_lock+0x447 #1 uvm_fault_check+0x41a sys/uvm/uvm_fault.c:782 #2 uvm_fault+0xf2 sys/uvm/uvm_fault.c:600 #3 upageflttrap+0x86 sys/arch/amd64/amd64/trap.c:188 #4 usertrap+0x226 sys/arch/amd64/amd64/trap.c:436 #5 recall_trap+0x8 shared rwlock vmmaplk r = 0 (0xfffffd806d7a02d8) #0 witness_lock+0x447 #1 uvmfault_lookup+0xd9 sys/uvm/uvm_fault.c:1785 #2 uvm_fault_check+0x3e sys/uvm/uvm_fault.c:672 #3 uvm_fault+0xf2 sys/uvm/uvm_fault.c:600 #4 upageflttrap+0x86 sys/arch/amd64/amd64/trap.c:188 #5 usertrap+0x226 sys/arch/amd64/amd64/trap.c:436 #6 recall_trap+0x8 Process 27523 (syz-executor.7) thread 0xffff8000212b0d50 (9407) exclusive rrwlock inode r = 0 (0xfffffd806d60da38) #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 (0xfffffd80672c7c58) #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 10189 6408K 6420K 78643K 11303 0 pcb 13 12K 14K 78643K 17 0 rtable 240 6K 7K 78643K 5232 0 pf 29 8K 8K 78643K 53 0 ifaddr 44 15K 15K 78643K 96 0 ifgroup 50 2K 2K 78643K 98 0 sysctl 3 1K 1K 78643K 3 0 counters 60 35K 35K 78643K 84 0 ioctlops 0 0K 2K 78643K 67 0 iov 0 0K 32K 78643K 349 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1278 80K 80K 78643K 1986 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 71 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 1K 78643K 1139 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 21 77K 125K 78643K 5529 0 sigio 0 0K 0K 78643K 91 0 proc 56 78K 103K 78643K 1071 0 subproc 104 6K 6K 78643K 260 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 176 0 in_multi 99 7K 7K 78643K 290 0 ether_multi 1 0K 0K 78643K 13 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 73 334K 334K 78643K 73 0 exec 0 0K 1K 78643K 1669 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 411 93K 103K 78643K 56250 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 0 0K 0K 78643K 102 0 NDP 11 0K 2K 78643K 63 0 temp 74 5920K 5999K 78643K 17014 0 kqueue 12 18K 28K 78643K 503 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 5355 0 5352 32 31 1 7 0 8 0 rtentry 112 255 0 142 4 0 4 4 0 8 0 unpcb 144 2946 0 2931 26 25 1 8 0 8 0 syncache 304 64 0 64 11 11 0 1 0 8 0 tcpqe 32 177 0 177 11 11 0 1 0 8 0 tcpcb 808 4002 0 3996 83 79 4 14 0 8 3 arp 120 43 0 25 1 0 1 1 0 8 0 ipq 40 78 0 78 3 3 0 1 0 8 0 ipqe 40 168 0 168 3 3 0 1 0 8 0 inpcb 368 5780 0 5771 78 74 4 17 0 8 2 nd6 136 71 0 44 3 2 1 2 0 8 0 kcovpl 48 20 0 12 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1004 0 542 30 1 29 30 0 8 0 art_table 32 1005 0 542 4 0 4 4 0 8 0 art_node 16 254 0 151 1 0 1 1 0 8 0 sysvmsgpl 40 12 0 2 1 0 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 1127 0 1117 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 8090 0 6647 91 0 91 91 0 8 0 ffsino 272 8090 0 6647 97 0 97 97 0 8 0 nchpl 144 15316 0 13677 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 48828 0 48827 4 3 1 3 0 8 0 percpumem 16 55 0 12 1 0 1 1 0 8 0 kstatmem 264 46 0 24 2 0 2 2 0 8 0 scxspl 216 43646 0 43645 25 24 1 8 1 8 0 plimitpl 152 926 0 903 7 6 1 2 0 8 0 sigapl 424 5802 0 5751 7 0 7 7 0 8 0 futexpl 64 44948 0 44946 1 0 1 1 0 8 0 knotepl 120 530 0 0 11 0 11 11 0 8 0 kqueuepl 216 3312 0 3304 30 27 3 8 0 8 2 pipepl 320 1632 0 1604 33 30 3 11 0 8 0 fdescpl 496 5784 0 5752 6 1 5 6 0 8 0 filepl 152 38330 0 38090 70 57 13 20 0 8 3 lockfpl 104 452 0 450 1 0 1 1 0 8 0 lockfspl 48 185 0 183 1 0 1 1 0 8 0 sessionpl 144 35 0 19 1 0 1 1 0 8 0 pgrppl 48 139 0 123 1 0 1 1 0 8 0 ucredpl 104 3861 0 3843 1 0 1 1 0 8 0 zombiepl 144 5752 0 5751 1 0 1 1 0 8 0 processpl 1072 5802 0 5751 5 1 4 5 0 8 0 procpl 680 15535 0 15462 21 13 8 9 0 8 1 sosppl 168 67 0 67 11 11 0 1 0 8 0 sockpl 488 14304 0 14277 262 253 9 33 0 8 5 mcl64k 65536 19 0 0 3 0 3 3 0 8 0 mcl16k 16384 18 0 0 3 0 3 3 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 11 0 0 1 0 1 1 0 8 0 mcl8k 8192 21 0 0 3 0 3 3 0 8 0 mcl4k 4096 33 0 0 3 0 3 3 0 8 0 mcl2k2 2112 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 361 0 0 39 3 36 39 0 8 0 mtagpl 96 17 0 0 1 0 1 1 0 8 0 mbufpl 256 1377 0 0 79 1 78 78 0 8 0 bufpl 288 11419 0 5093 452 0 452 452 0 8 0 anonpl 24 744742 0 733507 167 79 88 108 0 186 0 amapchunkpl 152 178680 0 177842 81 44 37 46 0 158 1 amappl16 200 17814 0 17505 115 97 18 36 0 8 1 amappl15 192 13 0 12 1 0 1 1 0 8 0 amappl14 184 195 0 179 2 1 1 2 0 8 0 amappl13 176 25 0 25 4 4 0 1 0 8 0 amappl12 168 6594 0 6555 2 0 2 2 0 8 0 amappl11 160 51 0 41 1 0 1 1 0 8 0 amappl10 152 38 0 26 1 0 1 1 0 8 0 amappl9 144 247 0 246 1 0 1 1 0 8 0 amappl8 136 587 0 454 5 0 5 5 0 8 0 amappl7 128 107 0 91 2 0 2 2 0 8 0 amappl6 120 379 0 355 3 2 1 3 0 8 0 amappl5 112 335 0 326 1 0 1 1 0 8 0 amappl4 104 780 0 735 2 0 2 2 0 8 0 amappl3 96 35285 0 35197 3 0 3 3 0 8 0 amappl2 88 6299 0 6228 3 1 2 3 0 8 0 amappl1 80 29241 0 28719 22 10 12 22 0 8 0 amappl 88 55410 0 55158 8 1 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 5784 0 5752 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 5784 0 5752 1 0 1 1 0 8 0 vmmpekpl 168 50906 0 50840 4 0 4 4 0 8 0 vmmpepl 168 357777 0 355434 217 103 114 131 0 357 2 vmsppl 464 5783 0 5752 6 1 5 6 0 8 0 rwobjpl 56 101278 0 93832 114 7 107 108 0 8 0 pdppl 4096 11576 0 11504 348 266 82 96 0 8 10 pvpl 32 1848122 0 1830929 373 208 165 334 0 265 0 pmappl 248 5783 0 5752 3 0 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1341 0 442 27 0 27 27 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 __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x30 kd_curproc sys/dev/kcov.c:590 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x30 sys/dev/kcov.c:158 __mp_lock(ffffffff82cc89c8) at __mp_lock+0x133 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82cc89c8) at __mp_lock+0x133 sys/kern/kern_lock.c:147 wakeup_n(ffffffff82cc9104,ffffffff) at wakeup_n+0x37 sys/kern/kern_synch.c:541 uvm_pmr_getpages(1,0,0,1,0,1,439912676cdbbe38,fffffd805faa3d68) at uvm_pmr_getpages+0xeef sys/uvm/uvm_pmemrange.c:1207 uvm_pagealloc(0,0,fffffd805faa3d68,2) at uvm_pagealloc+0x1a8 sys/uvm/uvm_page.c:910 uvm_fault_lower(ffff80002e45f400,ffff80002e45f438,ffff80002e45f380,0) at uvm_fault_lower+0x1ab uvm_fault(fffffd806d7a01e0,853020fa000,0,2) at uvm_fault+0x238 upageflttrap(ffff80002e45f580,853020fa958) at upageflttrap+0x86 sys/arch/amd64/amd64/trap.c:188 usertrap(ffff80002e45f580) at usertrap+0x226 sys/arch/amd64/amd64/trap.c:436 recall_trap() at recall_trap+0x8 end trace frame: 0x0, 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(ffff8000ffff8548,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff8000ffff8548,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff8000ffff8538) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff8000212b1d40,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff8000212b1d40,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff8000212b1d40,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff8000212b1d40,6,ffff80002e464ff8) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff8000212b1d40) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff80002e465130) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff80002e465130) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe3858742cf0, count: -9