Function find_in_directory 

pub fn find_in_directory<T>(
    path: &Path,
    visit: impl FnMut(&OsStr) -> Option<T>,
) -> Result<Option<T>>

Calls visit with each name in directory path, without . and .., in the kernel’s order, until it returns Some, and returns that value (None when every name was visited).

Read with raw getdents64 into one fixed buffer from Rust’s allocator, never with std::fs::read_dir: that calls glibc’s opendir, whose directory buffer comes from the C library’s malloc. Under in-guest LiteInst, Detcore runs inside the guest and that heap is the guest’s: the freed buffer would keep the kernel’s bytes (raw /proc inode numbers, say) where the guest’s next allocation finds them, so the guest could observe host-chosen data, for example in the padding of its own getdents64 records. Rust’s allocator is private to the runtime there (inside a Tool callback or an allocation scope). The names are streamed, not collected, so a directory of any size costs the one buffer.