login: kernel: protection fault trap, code=0
Stopped at      sys_semop+0x3d5:        movzwl  0(%rax),%r15d
ddb> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
the kernel did not panic
ddb> trace
sys_semop(ffff8000338cfa10,ffff80003c8f7330,ffff80003c8f7280) at sys_semop+0x3d5 sys/kern/sysv_sem.c:619
syscall(ffff80003c8f7330) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c8f7330) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7634645d360, count: -3
ddb> show registers
rdi                                0
rsi                                0
rbp               0xffff80003c8f7260
rbx               0xdeaf4152deaf4152
rdx                                0
rcx                                0
rax               0xdeaf4152deaf4152
r8                    0x7f7fffffc000
r9                                 0
r10               0x8c6b6dfcfd95be85
r11               0x7168f66aab68757d
r12                                0
r13               0xfffffd806cacfc40
r14               0xffff80003c8f7330
r15                                0
rip               0xffffffff81521f75    sys_semop+0x3d5
cs                               0x8
rflags                       0x10246    __ALIGN_SIZE+0xf246
rsp               0xffff80003c8f7170
ss                              0x10
sys_semop+0x3d5:        movzwl  0(%rax),%r15d
ddb>