The spec isn't really relevant to the point I'm making. I'm talking about what the purpose of the design is. Memory protection as a feature exists in order to (

The spec isn't really relevant to the point I'm making. I'm talking about what the purpose of the design is. Memory protection as a feature exists in order to (among other things) prevent code in ring 3 from reading data in ring 0 that ring 0 has not explicitly granted permission to read. If the implementation fails to do that, then it's failed to achieve its goal, and the whole exercise is pointless—why include the silicon at all? Documented bugs are still bugs. Again to use the crypto analogy: An implementation of, say, RSA that uses timing-sensitive memcmp to compare signatures would follow the RSA specification. But everyone would agree that such software has a severe bug.