Function do_readlink 

fn do_readlink(
    r: &Req<'_>,
    dirfd: i32,
    path: &[u8],
    buf: u64,
    bufsiz: usize,
) -> Result<Outcome, i32>

readlink/readlinkat: raw target, except /proc magic links are detranslated.

An empty path names the link dirfd was opened on. Where that is no link, the answer is ENOENT, as the kernel’s is.