Self-modifying code is something there doesn't seem to be much talk about, so here's some basic examples of it!

Current examples:

• Basic control flow
• Basic printf
• Factorial
• Hello, World!

There's currently only x86 linux examples currently, I may look into windows and llvm in the future.

Go into the directory of the code you want to run and execute ../execute.sh code-name. For example: ../execute.sh factorial.

• nasm
• ld
• objcopy
• objdump
• libc:i386

If you look at the execute script, you'll notice that it's a bit odd. ld has --omagic to allow the .text section to be written, but that also disables dynamic linking. objcopy is used to make the .text section writable, but because of a bug, another script from stackoverflow is used to fix it.

The normal method of writing self-modifying code is to allocate your own memory and do a dance where sometimes it's executable and sometimes its writable. That's a pain, so the program just tells the system that .text is modifiable through a flag here.

Not all of the code will follow proper calling conventions and have a regular formatting. I'm a reverse engineer, not an assembly programmer.