C can't do provenance
C can't do provenance
Posted Sep 29, 2024 21:55 UTC (Sun) by NYKevin (subscriber, #129325)In reply to: C can't do provenance by SLi
Parent article: Linus and Dirk on succession, Rust, and more
Yes, where the pointer came from is the whole point of provenance. That's because if the pointer came "from nowhere," or from an unrelated pointer, then on CHERI it will not have the correct metadata (or any metadata), and so dereferencing it will trap. The Rust provenance rules are intended to make it possible for a (currently hypothetical) CHERI backend to emit the necessary instructions to preserve every pointer's metadata.
What I'm getting at is that provenance is not an optimization technique. It is a hardware constraint.
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