+/**
+ * make address-sanitizer skip this:
+ * clib_mem_unaligned + zap64 casts its input as u64, computes a mask
+ * according to the input length, and returns the casted maked value.
+ * Therefore all the 8 Bytes of the u64 are systematically read, which
+ * rightfully causes address-sanitizer to raise an error on smaller inputs.
+ *
+ * However the invalid Bytes are discarded within zap64(), which is why
+ * this can be silenced safely.
+ *
+ * The above is true *unless* the extra bytes cross a page boundary
+ * into unmapped or no-access space, hence the boundary crossing check.
+ */