I am not saying these don't work, and I don't know why people seem hell bent on interpreting everything I'm saying as "X does not work" when that was not anywhe

I am not saying these don't work, and I don't know why people seem hell bent on interpreting everything I'm saying as "X does not work" when that was not anywhere in anything I said. I said, very clearly, that these mitigations are necessary because of code written in unsafe languages, and that these mitigations are not free. Some basic googling says that on an M7 there are 4 bit tags with a 64byte granularity. Now before any other costs you are burn 0.8% of your memory on these tags. The other costs are along the lines of increased chip complexity (caches, logic, lookahead/ooo etc). It may be that we're ok with these costs, but that doesn't change the fact that the costs exist, and that the exist largely to mitigate exploits in unsafe code.