login: witness: lock order reversal:
 1st 0xffff800001571968 sbufsnd (&so->so_snd.sb_lock)
 2nd 0xfffffd806c524b30 inode (&ip->i_lock)
lock order [1] sbufsnd (&so->so_snd.sb_lock) -> [2] inode (&ip->i_lock)
lock order data 0xffffffff8350c4d7 -> 0xffffffff8347b7ef is missing
lock order [2] inode (&ip->i_lock) -> [3] sbufrcv (&so->so_rcv.sb_lock)
#0  rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234
#1  sblock+0xb6 sys/kern/uipc_socket2.c:536
#2  soreceive+0x27d sys/kern/uipc_socket.c:890
#3  fifo_read+0x117 sys/miscfs/fifofs/fifo_vnops.c:264
#4  VOP_READ+0x101 sys/kern/vfs_vops.c:227
#5  vn_rdwr+0x15b sys/kern/vfs_vnops.c:-1
#6  vndsetcred+0xa1 sys/dev/vnd.c:685
#7  vndioctl+0xdfc sys/dev/vnd.c:486
#8  VOP_IOCTL+0xac sys/kern/vfs_vops.c:264
#9  vn_ioctl+0xf8 sys/kern/vfs_vnops.c:537
#10 sys_ioctl+0x674 sys/kern/sys_generic.c:-1
#11 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#11 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#12 Xsyscall+0x128
lock order [3] sbufrcv (&so->so_rcv.sb_lock) -> [1] sbufsnd (&so->so_snd.sb_lock)
#0  rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234
#1  sblock+0xb6 sys/kern/uipc_socket2.c:536
#2  sosplice+0x312 sys/kern/uipc_socket.c:1347
#3  sys_setsockopt+0x2ba sys/kern/uipc_syscalls.c:1226
#4  syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#4  syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#5  Xsyscall+0x128
Stopped at      db_enter+0x25:  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+0x25 sys/arch/amd64/amd64/db_interface.c:438
witness_checkorder(fffffd806c524b30,9,0) at witness_checkorder+0x10d1 sys/kern/subr_witness.c:-1
rw_do_enter_write(fffffd806c524b18,1) at rw_do_enter_write+0xba sys/kern/kern_rwlock.c:234
rrw_enter(fffffd806c524b18,1) at rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
VOP_LOCK(fffffd805ecb5100,2001) at VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
vn_lock(fffffd805ecb5100,2001) at vn_lock+0xa4 sys/kern/vfs_vnops.c:576
vfs_lookup(ffff80002a288100) at vfs_lookup+0x10f sys/kern/vfs_lookup.c:431
namei(ffff80002a288100) at namei+0x7c5 sys/kern/vfs_lookup.c:250
unp_connect(ffff800001571780,fffffd806db3e100,ffff80002a223a00) at unp_connect+0x29d sys/kern/uipc_usrreq.c:872
uipc_dgram_send(ffff800001571780,fffffd806c513700,fffffd806db3e100,0) at uipc_dgram_send+0x163 sys/kern/uipc_usrreq.c:609
sosend(ffff800001571780,fffffd806db3e100,ffff80002a288388,0,0,402) at sosend+0x804 sys/kern/uipc_socket.c:-1
sendit(ffff80002a223a00,6,ffff80002a288500,402,ffff80002a288538) at sendit+0x5a5 sys/kern/uipc_syscalls.c:785
sys_sendmmsg(ffff80002a223a00,ffff80002a2886b0,ffff80002a288600) at sys_sendmmsg+0x3f3 sys/kern/uipc_syscalls.c:676
syscall(ffff80002a2886b0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2886b0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xec29358c990, count: -15
ddb{0}> show registers
rdi                                0
rsi                          0x80000    acpi_pdirpa+0x6be71
rbp               0xffff80002a287d70
rbx                                0
rdx               0xffff8000015ced40
rcx               0xffff80002a223a00
rax                          0x7ffff    acpi_pdirpa+0x6be70
r8                0xffff80002a287c50
r9                0x8080808080808080
r10               0x2abd6018007d606e
r11               0xba8562535e05e7f8
r12               0xfffffd80040b08c0
r13               0xfffffd8004898020
r14                              0x3
r15               0xffffffff83512ed3    substchar+0x5b7c
rip               0xffffffff8258b975    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff80002a287d60
ss                              0x10
db_enter+0x25:  addq    $0x8,%rsp
ddb{0}>