Enable write protect bit to improve safety

src/lib.rs

@@ -46,6 +46,7 @@ pub extern fn rust_main(multiboot_information_address: usize) {
         multiboot_end, memory_map_tag.memory_areas());
 
     enable_nxe_bit();
+    enable_write_protect_bit();
     memory::remap_the_kernel(&mut frame_allocator, boot_info);
     println!("It did not crash!");
 
@@ -62,6 +63,12 @@ fn enable_nxe_bit() {
     }
 }
 
+fn enable_write_protect_bit() {
+    use x86_64::registers::control_regs::{cr0, cr0_write, Cr0};
+
+    unsafe { cr0_write(cr0() | Cr0::WRITE_PROTECT) };
+}
+
 #[lang = "eh_personality"] extern fn eh_personality() {}
 
 #[lang = "panic_fmt"]