They are semantically simple string operations whose computational complexity scales with string length.
Near unbound string lengths would exhaust the time (somewhat aproximated by instruction) budget of eBPF applications doing even a single one.
I think the point was not to show "there are a lot of helper functions" but rather to point out "the (undocumented) helper functions that exist are problematic"
Write an eBPF program that actually needs to do any kind of meaningful string manipulation, and you'll quickly get a sense of just how rich the BPF helper inventory is in string processing functions. It'll be sharply obvious, because bounded loop enforcement will keep you from writing even the simplest string functions yourself.
There are others listed in the thread. The specific quantity of 'quite a few' is orthogonal to the core point and was intentionally left vague in what now appears to be a misguided attempt to keep the comment concise and focused.
They are semantically simple string operations whose computational complexity scales with string length. Near unbound string lengths would exhaust the time (somewhat aproximated by instruction) budget of eBPF applications doing even a single one.