I think you are getting at the same question Alan Cox had. As quoted in the article: IMHO the question is what is the actual semantic here. What are you askin

I think you are getting at the same question Alan Cox had. As quoted in the article: IMHO the question is what is the actual semantic here. What are you asking for ? Does it mean "at any cost", what does it guarantee (100% or statistically), what level of guarantee is acceptable, what level is -EOPNOTSUPP or similar ? I think different semantics as Cox mentions would correspond to different threat models. With the right hardware support, it could mitigate against a kernel that falls under an attacker's complete control after the memory has been allocated. With less support it could mitigate against an attacker who can exploit read accesses at kernel privilege. But the details seem a bit open still...