I'm the developer of 8th (https://8th-dev.com), which compiles the program at run-time, on the device. There used to be an iOS version which worked, but it seems things have changed since then.
I'm trying to distribute an iOS version of an app written in 8th, and am encountering "SIGKILL - CODESIGNING" when trying to execute freshly compiled code. I am doing the 'sys_icache_invalidate' thing after writing into a mmap'ed bit of memory (rwx).
I'm not writing into memory that was codesigned, so I don't know why the error is that.
Anyway, the question is: is it possible any more to do what I used to be able to do?
This page is worth reading:
describes how it works on MacOS.
I believe that iOS likely works much the same, except crucially that our apps cannot get the required entitlement.