auditor

An aarch64 constant-time memory access auditing tool.
git clone git://git.ppad.tech/auditor.git
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IMPL12.md (1356B)

      1 # IMPL12: Implement Array-Backed Register Taint/Provenance
      2 
      3 ## Summary
      4 
      5 Refactor `TaintState` to use `SmallArray` for register taint and
      6 provenance, and make block analysis folds strict.
      7 
      8 ## Steps
      9 
     10 1) Add register indexing
     11 - Define `regIndex :: Reg -> Int` and `regCount :: Int`.
     12 - Provide total mapping for all `Reg` constructors.
     13 
     14 2) Update TaintState
     15 - Replace `tsRegs :: Map Reg Taint` with `tsRegs :: SmallArray Taint`.
     16 - Replace `tsProv :: Map Reg Provenance` with `tsProv :: SmallArray Provenance`.
     17 - Keep `tsStack`/`tsStackProv` unchanged.
     18 
     19 3) Access helpers
     20 - Add `getRegTaint`, `setRegTaint`, `getRegProv`, `setRegProv`.
     21 - Update `getTaint`/`setTaint`/`getProvenance` and call sites.
     22 
     23 4) Initialization
     24 - Build arrays with defaults (Unknown/ProvUnknown).
     25 - Overwrite `publicRoots` indices to Public/ProvPublic.
     26 
     27 5) Strict folds
     28 - Use `foldl'` in `analyzeBlock` and `analyzeBlockWithSummaries`.
     29 
     30 6) Update joins
     31 - Implement `joinTaintState` with element-wise array zip.
     32 - Consider an ST-based update for fewer allocations if needed.
     33 
     34 7) Tests/Validation
     35 - Re-run taint tests; add a small test for register array indexing.
     36 - `cabal test` and (optionally) benchmark deltas.
     37 
     38 ## Files to Touch
     39 
     40 - `lib/Audit/AArch64/Taint.hs`
     41 - `lib/Audit/AArch64/Types.hs` (if Reg mapping helpers live there)
     42 - `test/`
     43 
     44 ## Validation
     45 
     46 - `cabal test`
     47 - `cabal bench`