How is JIT compiled code injected in memory and executed?

Question

"Consider a typical Windows x86 or AMD64 architecture, the memory is divided in executable sections that cannot be written to and data sections that can be wri

Answer 1

It is simply done with the Windows VirtualProtect() API function. It changes the virtual memory page attributes. From PAGE_READWRITE so the JIT compiler can write the machine code to PAGE_EXECUTE_READ so it can be executed. No special privileges are required to do so since the page is owned by the process that also runs the JIT compiler.