Starnge INVALID_OPCODE exception when initialising IDT (64-bit kernel)

Here is the code that sets up the IDT.

global lngmd_startextern kernel_mainextern gdt.datasection .textbits 64lngmd_start:    mov ax, gdt.data    mov ss, ax    mov ds, ax    mov es, ax    mov fs, ax    mov gs, ax   call map_entries   lidt [idt.pointer]   sti   ;call kernel_main   ;int 0x00    jmp krnl_hltmap_entries:   mov rbx, idt.map_exceptions:   mov rdx, 0   mov r8, exception_handler   mov rcx, 32   jmp .loop.map_irqs_pic1:   mov rdx, 1   mov r8, isr_handler.pic1   mov rcx, 8   jmp .loop.map_irqs_pic2:   mov rdx, 2   mov r8, isr_handler.pic2   mov rcx, 8.loop:   mov rax, r8    mov word [rbx], ax   shr rax, 16   mov word [rbx + 6], ax   shr rax, 16   mov dword [rbx + 8], eax   add rbx, 16   dec rcx   ;jmp krnl_hlt ; This works as intended and halts the kernel, printing "a2"   jne .loop   jmp krnl_hlt ; this is supposed to print "a2" then halt, but causes an INVALID_OPCODE (0x6 in QEMU debugger) exception. Removing this jump causes the code to hang with no exceptions.   test rdx, rdx   je .map_irqs_pic1   dec rdx   test rdx, rdx   je .map_irqs_pic2   retidt:.exception_0:        dw 0        dw 0x8        db 0        db 10001110b        dw 0        dd 0        dd 0; --------------------------------; exceptions 1 - 30; --------------------------------.exception_31:        dw 0        dw 0x8        db 0        db 10001110b        dw 0        dd 0        dd 0.irq_0:   dw 0   dw 0x8   db 0   db 10001110b   dw 0   dd 0   dd 0; --------------------------------; irqs 1 - 14; --------------------------------.irq_15:        dw 0        dw 0x8        db 0        db 10001110b        dw 0        dd 0        dd 0.pointer:        dw $ - idt - 1        dq idtexception_handler:   jmp krnl_hltisr_handler:.pic1:   mov ax, 0x20   out 0x20, ax   iretq.pic2:   mov ax, 0x20   out 0xa0, ax   iretqkrnl_hlt:    mov dword [0xb8000], 0x0c320c61    abbc:   hlt   nop    jmp abbc

I have spent the last 5 hours trying different ways to get this IDT working through many different methods, and I don't normally ask questions, but it seems I've hit a dead end. If I've missed any required info or asked a "bad question", let me know and I will try to make it better.