witness: lock order reversal: 1st 0xffffffff82cc8bd0 &sched_lock (&sched_lock) 2nd 0xffff8000ffff4db8 &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(ffff8000ffff4db8,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff8000ffff4db8,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff8000ffff4da8) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff80002123b558,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff80002123b558,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff80002123b558,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff80002123b558,6,ffff80002ca18f98) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff80002123b558) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff80002ca190d0) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff80002ca190d0) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xa0135ea7d80, count: -9 ddb{1}> show registers rdi 0x3 rsi 0x40000 acpi_pdirpa+0x2be63 rbp 0xffff80002ca18ca0 rbx 0x3 rdx 0xffff800000d03a40 rcx 0xffff80002123b558 rax 0x3ffff acpi_pdirpa+0x2be62 r8 0xffff80002ca18c10 r9 0x8080808080808080 r10 0x1c776f3af2d568dc r11 0xf2055090735d70f2 r12 0xfffffd8003a0a850 r13 0 r14 0xfffffd80039fb180 r15 0xfffffd80031c7bc0 rip 0xffffffff81b6e27c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff80002ca18c90 ss 0x10 db_enter+0x1c: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.2) pid=495174 stat=onproc flags process=500010 proc=4002000 pri=32, usrpri=65, nice=20 forw=0xffffffffffffffff, list=0xffff80002123b800,0xffff80002123b018 process=0xffff8000ffff4ca8 user=0xffff80002ca14000, vmspace=0xfffffd806ba6ecc8 estcpu=15, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 27892 520253 38624 32767 2 0x10 syz-executor.4 27892 14263 38624 32767 3 0x4000090 kqread syz-executor.4 43353 12447 41019 32767 4 0x582010 syz-executor.2 *43353 495174 41019 32767 7 0x4502010 syz-executor.2 12031 445677 53403 32767 2 0x10 syz-executor.0 12031 126840 53403 32767 3 0x4000090 fsleep syz-executor.0 80308 155429 31726 32767 2 0x10 syz-executor.7 78275 438214 15833 32767 7 0x10 syz-executor.6 33564 138647 26906 32767 2 0x10 syz-executor.3 33564 223056 26906 32767 3 0x4000090 fsleep syz-executor.3 28447 206291 4107 32767 2 0x10 syz-executor.1 68587 95908 38178 32767 2 0x10 syz-executor.5 31726 276743 127 32767 2 0x10 syz-executor.7 127 78743 55890 0 3 0x82 wait syz-executor.7 15833 487723 67384 32767 3 0x90 nanoslp syz-executor.6 38178 457987 34987 32767 3 0x90 nanoslp syz-executor.5 38624 313366 62042 32767 3 0x90 nanoslp syz-executor.4 67384 86137 55890 0 3 0x82 wait syz-executor.6 34987 484034 55890 0 3 0x82 wait syz-executor.5 62042 156764 55890 0 3 0x82 wait syz-executor.4 26906 90558 51617 32767 3 0x90 nanoslp syz-executor.3 41019 497015 27750 32767 3 0x90 nanoslp syz-executor.2 27750 478283 55890 0 3 0x82 wait syz-executor.2 51617 68557 55890 0 3 0x82 wait syz-executor.3 4107 197401 10716 32767 3 0x90 nanoslp syz-executor.1 53403 81084 34775 32767 2 0x10 syz-executor.0 10716 268355 55890 0 3 0x82 wait syz-executor.1 34775 27545 55890 0 3 0x82 wait syz-executor.0 55890 51446 2614 0 3 0x2000082 wait syz-fuzzer 55890 348453 2614 0 3 0x6000082 thrsleep syz-fuzzer 55890 179392 2614 0 3 0x6000082 wait syz-fuzzer 55890 113197 2614 0 3 0x6000082 thrsleep syz-fuzzer 55890 227902 2614 0 3 0x6000082 thrsleep syz-fuzzer 55890 134195 2614 0 3 0x6000082 wait syz-fuzzer 55890 96692 2614 0 3 0x6000082 thrsleep syz-fuzzer 55890 338251 2614 0 3 0x6000082 wait syz-fuzzer 55890 51343 2614 0 3 0x6000082 wait syz-fuzzer 55890 171044 2614 0 3 0x6000082 thrsleep syz-fuzzer 55890 105493 2614 0 3 0x6000082 wait syz-fuzzer 55890 453945 2614 0 3 0x6000082 wait syz-fuzzer 55890 364972 2614 0 3 0x6000082 thrsleep syz-fuzzer 55890 96936 2614 0 3 0x6000082 wait syz-fuzzer 55890 294698 2614 0 3 0x6000082 thrsleep syz-fuzzer 55890 434623 2614 0 3 0x6000082 kqread syz-fuzzer 2614 241464 22396 0 3 0x10008a sigsusp ksh 22396 57085 27683 0 3 0x9a kqread sshd 30501 298669 1 0 3 0x100083 ttyin getty 27683 24504 1 0 3 0x88 kqread sshd 37752 159599 63101 73 3 0x1100090 kqread syslogd 63101 335794 1 0 3 0x100082 netio syslogd 87014 234411 1 0 3 0x100080 kqread resolvd 22127 418007 91508 77 3 0x100092 kqread dhcpleased 35887 37985 91508 77 3 0x100092 kqread dhcpleased 91508 368527 1 0 3 0x80 kqread dhcpleased 7193 388333 0 0 3 0x14200 bored smr 19871 41398 0 0 2 0x14200 zerothread 13020 242920 0 0 3 0x14200 aiodoned aiodoned 38555 480956 0 0 3 0x14200 syncer update 46691 365452 0 0 3 0x14200 cleaner cleaner 48136 33569 0 0 3 0x14200 reaper reaper 52657 473816 0 0 3 0x14200 pgdaemon pagedaemon 70558 204990 0 0 3 0x14200 bored viomb 26259 499239 0 0 3 0x40014200 acpi0 acpi0 68721 286075 0 0 3 0x40014200 idle1 5051 509262 0 0 3 0x14200 bored softnet3 1412 214343 0 0 3 0x14200 bored softnet2 59733 78143 0 0 3 0x14200 bored softnet1 93441 422590 0 0 3 0x14200 bored softnet0 89149 153393 0 0 3 0x14200 bored systqmp 46790 247102 0 0 3 0x14200 bored systq 49566 35000 0 0 3 0x40014200 bored softclock 61343 125830 0 0 3 0x40014200 idle0 1 184054 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 pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1209 #6 pmap_enter+0x2be sys/arch/amd64/amd64/pmap.c:2716 #7 uvm_fault_upper_lookup+0x2c0 sys/uvm/uvm_fault.c:895 #8 uvm_fault+0x129 sys/uvm/uvm_fault.c:605 #9 upageflttrap+0x86 sys/arch/amd64/amd64/trap.c:188 #10 usertrap+0x226 sys/arch/amd64/amd64/trap.c:436 #11 recall_trap+0x8 exclusive mutex &pmap->pm_mtx r = 0 (0xfffffd806b9382f8) #0 witness_lock+0x447 #1 mtx_enter_try+0x104 #2 mtx_enter+0x4f sys/kern/kern_lock.c:266 #3 pmap_enter+0x1c3 pmap_map_ptes sys/arch/amd64/amd64/pmap.c:423 [inline] #3 pmap_enter+0x1c3 sys/arch/amd64/amd64/pmap.c:2710 #4 uvm_fault_upper_lookup+0x2c0 sys/uvm/uvm_fault.c:895 #5 uvm_fault+0x129 sys/uvm/uvm_fault.c:605 #6 upageflttrap+0x86 sys/arch/amd64/amd64/trap.c:188 #7 usertrap+0x226 sys/arch/amd64/amd64/trap.c:436 #8 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 43353 (syz-executor.2) thread 0xffff80002123b558 (495174) 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 78275 (syz-executor.6) thread 0xffff8000212962a8 (438214) exclusive rwlock amaplk r = 0 (0xfffffd806a3feec0) #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 (0xfffffd8071bccdd0) #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 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10183 6407K 6420K 78643K 11261 0 pcb 13 8K 8K 78643K 13 0 rtable 234 6K 6K 78643K 350 0 pf 29 8K 8K 78643K 29 0 ifaddr 44 15K 15K 78643K 46 0 ifgroup 50 2K 2K 78643K 50 0 counters 60 35K 35K 78643K 60 0 ioctlops 0 0K 2K 78643K 394 0 iov 0 0K 0K 78643K 761 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1278 80K 80K 78643K 1291 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 5 0 VM map 2 1K 1K 78643K 2 0 sem 5 0K 0K 78643K 5 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 26 97K 117K 78643K 6757 0 proc 56 78K 115K 78643K 1377 0 subproc 104 6K 6K 78643K 104 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 99 7K 7K 78643K 99 0 ether_multi 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 43 201K 201K 78643K 43 0 exec 0 0K 1K 78643K 361 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 331 82K 83K 78643K 59910 0 UVM aobj 131 4K 4K 78643K 131 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 11 0K 2K 78643K 27 0 temp 33 5906K 5970K 78643K 17323 0 kqueue 12 18K 20K 78643K 25 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 36 0 33 1 0 1 1 0 8 0 rtentry 112 111 0 1 4 0 4 4 0 8 0 unpcb 144 2254 0 2239 6 5 1 4 0 8 0 syncache 304 4 0 4 1 1 0 1 0 8 0 tcpqe 32 161 0 161 1 1 0 1 0 8 0 tcpcb 808 8 0 4 1 0 1 1 0 8 0 arp 120 18 0 0 1 0 1 1 0 8 0 inpcb 368 58 0 51 1 0 1 1 0 8 0 nd6 136 24 0 0 1 0 1 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 452 0 0 29 0 29 29 0 8 0 art_table 32 453 0 0 4 0 4 4 0 8 0 art_node 16 110 0 10 1 0 1 1 0 8 0 semapl 112 3 0 0 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 8121 0 6683 91 0 91 91 0 8 0 ffsino 272 8121 0 6683 97 0 97 97 0 8 0 nchpl 144 19935 0 18255 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 46114 0 46114 4 3 1 3 0 8 1 percpumem 16 43 0 0 1 0 1 1 0 8 0 kstatmem 264 22 0 0 2 0 2 2 0 8 0 scxspl 216 46405 0 46405 10 9 1 8 1 8 1 plimitpl 152 41 0 18 1 0 1 1 0 8 0 sigapl 424 7052 0 6998 7 0 7 7 0 8 0 futexpl 64 56264 0 56262 1 0 1 1 0 8 0 knotepl 120 102 0 0 4 0 4 4 0 8 0 kqueuepl 216 1951 0 1941 12 11 1 7 0 8 0 pipepl 320 1804 0 1775 12 9 3 8 0 8 0 fdescpl 496 7035 0 6998 7 2 5 6 0 8 0 filepl 152 26371 0 26130 23 12 11 15 0 8 1 lockfpl 104 41 0 39 1 0 1 1 0 8 0 lockfspl 48 19 0 17 1 0 1 1 0 8 0 sessionpl 144 23 0 7 1 0 1 1 0 8 0 pgrppl 48 23 0 7 1 0 1 1 0 8 0 ucredpl 104 831 0 813 1 0 1 1 0 8 0 zombiepl 144 6998 0 6998 1 0 1 1 0 8 1 processpl 1072 7052 0 6998 4 0 4 4 0 8 0 procpl 680 14703 0 14630 9 2 7 8 0 8 0 sockpl 488 2466 0 2441 16 12 4 12 0 8 0 mcl64k 65536 17 0 0 3 0 3 3 0 8 0 mcl16k 16384 26 0 0 3 0 3 3 0 8 0 mcl12k 12288 21 0 0 2 0 2 2 0 8 0 mcl9k 9216 16 0 0 2 0 2 2 0 8 0 mcl8k 8192 33 0 0 4 1 3 3 0 8 0 mcl4k 4096 34 0 0 3 0 3 3 0 8 0 mcl2k2 2112 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 321 0 0 40 5 35 40 0 8 0 mtagpl 96 3 0 0 1 0 1 1 0 8 0 mbufpl 256 408 0 0 21 0 21 21 0 8 0 bufpl 288 10760 0 4433 453 0 453 453 0 8 0 anonpl 24 674674 0 667346 78 13 65 70 0 186 16 amapchunkpl 152 189614 0 188816 55 19 36 37 0 158 4 amappl16 200 12907 0 12751 21 9 12 21 0 8 3 amappl15 192 10 0 10 1 1 0 1 0 8 0 amappl14 184 158 0 146 2 1 1 2 0 8 0 amappl13 176 29 0 28 1 0 1 1 0 8 0 amappl12 168 7663 0 7627 3 1 2 3 0 8 0 amappl11 160 54 0 44 1 0 1 1 0 8 0 amappl10 152 46 0 34 1 0 1 1 0 8 0 amappl9 144 371 0 369 1 0 1 1 0 8 0 amappl8 136 405 0 336 3 0 3 3 0 8 0 amappl7 128 160 0 147 2 0 2 2 0 8 0 amappl6 120 382 0 365 1 0 1 1 0 8 0 amappl5 112 233 0 224 1 0 1 1 0 8 0 amappl4 104 784 0 748 2 0 2 2 0 8 0 amappl3 96 38317 0 38228 4 1 3 4 0 8 0 amappl2 88 7964 0 7896 3 1 2 3 0 8 0 amappl1 80 31271 0 30745 22 9 13 22 0 8 0 amappl 88 59399 0 59174 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 72 130 0 0 3 0 3 3 0 8 0 uaddrrnd 24 7035 0 6998 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 7035 0 6998 1 0 1 1 0 8 0 vmmpekpl 168 48563 0 48519 3 0 3 3 0 8 0 vmmpepl 168 392620 0 390371 127 24 103 110 0 357 2 vmsppl 464 7034 0 6998 7 2 5 6 0 8 0 rwobjpl 56 95077 0 87879 109 6 103 106 0 8 0 pdppl 4096 14078 0 13996 280 198 82 92 0 8 0 pvpl 32 1927559 0 1914109 368 232 136 339 0 265 19 pmappl 248 7034 0 6998 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1046 0 211 24 0 24 24 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+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(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,d2989f910bbd1ecf,0) at uvm_pmr_getpages+0xeef sys/uvm/uvm_pmemrange.c:1207 uvm_pagealloc(fffffd806b938338,3857000,0,3) at uvm_pagealloc+0x1a8 sys/uvm/uvm_page.c:910 pmap_get_ptp(fffffd806b9382e8,e15cb38e000) at pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1209 pmap_enter(fffffd806b9382e8,e15cb38e000,69065000,1,20) at pmap_enter+0x2be sys/arch/amd64/amd64/pmap.c:2716 uvm_fault_upper_lookup(ffff8000289c1720,ffff8000289c1758,ffff8000289c1620,ffff8000289c16a0) at uvm_fault_upper_lookup+0x2c0 sys/uvm/uvm_fault.c:895 uvm_fault(fffffd8071bcccd8,e15cb390000,0,1) at uvm_fault+0x129 sys/uvm/uvm_fault.c:605 upageflttrap(ffff8000289c18a0,e15cb390220) at upageflttrap+0x86 sys/arch/amd64/amd64/trap.c:188 usertrap(ffff8000289c18a0) at usertrap+0x226 sys/arch/amd64/amd64/trap.c:436 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7b407bddf400, count: -15 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(ffff8000ffff4db8,9,0) at witness_checkorder+0x10b7 witness_debugger sys/kern/subr_witness.c:2510 [inline] witness_checkorder(ffff8000ffff4db8,9,0) at witness_checkorder+0x10b7 sys/kern/subr_witness.c:1110 mtx_enter(ffff8000ffff4da8) at mtx_enter+0x3e sys/kern/kern_lock.c:265 single_thread_set(ffff80002123b558,0,1) at single_thread_set+0x35a single_thread_wait sys/kern/kern_sig.c:2172 [inline] single_thread_set(ffff80002123b558,0,1) at single_thread_set+0x35a sys/kern/kern_sig.c:2155 sigexit(ffff80002123b558,6) at sigexit+0x90 sys/kern/kern_sig.c:1562 postsig(ffff80002123b558,6,ffff80002ca18f98) at postsig+0x4a9 sys/kern/kern_sig.c:1494 userret(ffff80002123b558) at userret+0x16e sys/kern/kern_sig.c:1987 syscall(ffff80002ca190d0) at syscall+0x4e7 mi_syscall_return sys/sys/syscall_mi.h:137 [inline] syscall(ffff80002ca190d0) at syscall+0x4e7 sys/arch/amd64/amd64/trap.c:644 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xa0135ea7d80, count: -9