[amstan]

> Traditionally, programs will place their code into non-writeable memory, and store variable data in memory that is writeable but not executable. And that's definitely the safer way to do things, but we can't be bothered with all that.

Woah, I have a feeling this does something even more. If the program modifies its own instructions, the kernel will probably save those modifications in the file too.

[compressedgas]

That would be the behavior with the mmap(2) flag MAP_SHARED. The module built in the article uses MAP_PRIVATE. Any changes to the contents of a private mapping do not effect other processes or the file.