WHAT-IF: Reading uninit RAM was not UB?

[jplatte]

I had the impression that all these freeze ideas don't work in practice because of things like MADV_FREE:

"What The Hardware Does" is not What Your Program Does: Uninitialized Memory

Pretty much. This is essentially a data race, which you can somewhat get around by using volatile loads. However the “cute data structure” will definitely not work in such conditions.

Or does that only apply to a subset of things one might want to do with LLVM's freeze operation?

Also, kinda OT but if it applies to everything one would do with that operation, has this been discussed with the LLVM developers?