Safety improvements: mitigation for PR #390

neysofu commented 2 years ago

This is a follow-up PR to https://github.com/spacemeshos/svm/pull/411.

https://github.com/spacemeshos/svm/pull/390 fixed a Fixed-Gas regression in svm-abi-decoder, meaning that some code had been merged into master which caused the compiled .wasm artifacts to contain illegal loop instructions. This broke SVM Fixed-Gas mode, so we reverted back to using pointers within Cursor.

This PR mitigates the two issues:

It doesn't compile into any loop instructions and invalid WASM code.
It reverts some of the safety improvements applied before breaking Fixed-Gas. In particular, we introduce back explicit lifetimes, which help the compiler check for some useful invariants and reduces the UB surface.

neysofu commented 2 years ago

@kobby-pentangeli Can you please provide more details? How does your setup differ from the CI's, where these two tests indeed succeed?

kobby-pentangeli commented 2 years ago

@neysofu All tests pass when I run this branch inside of my WSL-Ubuntu-20.4-LTS (running on Windows 11). However, the two tests I referenced above fail on native Windows 11.

neysofu commented 2 years ago

Ok, let's make a note to investigate this in the future.

spacemeshos / svm

Safety improvements: mitigation for PR #390 #412