Solana BPF v3

[Lichtso]

• Specification
  • Add BTF features:
    • Rust trait type
    • Target type of transmutation / reinterpretation instructions
  • Remove BTF features:
    • Volatile
    • Floats
• Toolchain
  • ELF DT_NEEDED entries for defining on-chain addresses of dependencies
  • cargo (dependencies)
  • rustc (attribute)
  • LLVM: Lift C type restriction, inject runtime code for lifetime tracking
  • Emit canonical bounds checks of dynamic array sub-slicing
• Loader
  • Reject cyclic dependencies when deploying a program
  • Enforce redeployment maintains existing interfaces (function signatures and types)
  • [Optional] Support type migration
• ELF BTF section parser
• Type inference
  • Track types of registers
  • Track types of stack slots
• Verifier
  • Verify canonical bounds checks of dynamic array sub-slicing exist
  • Reject ptr transmutation / reinterpretation
  • Forbid ptr introspection or order based comparison, only allow equality test (check for aliasing)
  • Prevent pointers becoming unaligned

[ksolana]

For reference: the current work on btf parser and btf verifier is in https://github.com/ksolana/rbpf.