3 ms·
Disclaimer; I don't work at Intel, nor in any other processor design house, nor in a fab, etc. And honestly, look at what is variant 1, before spreading uninfo
by wilun 9y ago
Disclaimer; I don't work at Intel, nor in any other processor design house, nor in a fab, etc.
And honestly, look at what is variant 1, before spreading uninformed opinion. It is fundamental to speculative execution. You can have some form of hardware support, and actually both Intel, AMD, ARM, and probably others, have begun some work on the subject, but it is in the form of instructions that can be added or replaced in the software at the right spot, because there is absolutely no way to have a speculative enough HW enforce security for variant 1 without some software help: it is not an architectural or a microarchitectural problem; it is a fundamental logic problem...
My opinion is that we need extensible tagging in programing languages quickly, for that, and other subjects.
- modeless 9y agoI understand variant 1, and I do not share your pessimism. It is not fundamental to speculative execution as a concept, only current implementations. Speculative execution in modern processors already requires performing heroic feats to enforce correctness in the face of mispredicted branches. Fixing Spectre variant 1 requires more heroic feats of a similar kind (rolling back state changes), and I don't think it is fundamentally impossible given what has already been done. It won't be easy, and it won't be free, but it needs doing. Nobody thought it was worth doing until now, so nobody tried, but that doesn't indicate that it's impossible.