Function dr_custom_free 

pub unsafe extern "C" fn dr_custom_free(
    drcontext: *mut c_void,
    flags: dr_alloc_flags_t,
    addr: *mut c_void,
    size: usize,
) -> bool_

Frees memory allocated by dr_custom_alloc(). The same \p flags and \p size must be passed here as were passed to dr_custom_alloc().