The source code to the kernel's elf "binfmt"[0] is very readable. The elf binfmt is registered (along with a few others like `binfmt_misc`) and you get dispatched there via `exec_binprm`[1] which is invoked by the `execve` syscall[2]. When loading a shared library, you also dispatch to a binfmt via the `uselib`[3] syscall.

[0] https://github.com/torvalds/linux/blob/9fdfb15a3dbf818e06be5...

[1] https://github.com/torvalds/linux/blob/9fdfb15a3dbf818e06be5...

[2] https://github.com/torvalds/linux/blob/9fdfb15a3dbf818e06be5...

[3] https://github.com/torvalds/linux/blob/9fdfb15a3dbf818e06be5...

CPU Land is an accessible introduction. This chapter covers ELF https://cpu.land/becoming-an-elf-lord

The book "Linkers an Loaders" by Levine is the Bible on the subject

There's a great summary from LWN[1] with lots of references and links to other articles for further reading.

[1] https://lwn.net/Articles/631631

If you're interested in or already comfortable with Rust, Amos (fasterthanlime) has a nice long-form series that goes into this, basically building a custom ELF loader in the end. The writing style isn't everyone's cup of tea, but maybe you like it: https://fasterthanli.me/series/making-our-own-executable-pac...

"man 5 elf" should be the ultimate source of truth :-)

I've found that searching for stories with ELF in the title then trawling through the comments for the links is really informative.