Martin Fink
Please Note
3 records found
1
Arancini
A Hybrid Binary Translator for Weak Memory Model Architectures
Binary translation is a powerful approach to support cross-architecture emulation of unmodified binaries in increasingly heterogeneous computing environments. However, binary translation systems face correctness issues, due to the strong-on-weak memory model mismatch (e.g., from x86-64 to Arm/RISC-V) for concurrent programs. Besides, the current landscape of binary translation systems is fundamentally limited in terms of completeness for static systems and performance for dynamic ones.To address these limitations, we propose Arancini, a hybrid binary translator system designed and implemented from the ground up that strives for correct, complete, and efficient emulation for weak memory model architectures. Our system makes three foundational contributions to achieve these design goals: ArancinIR, a unified intermediate representation for static and dynamic binary translators; a formalization of ArancinIR,'s memory model and formally verified mapping schemes from x86-6 to Arm and RISC-V, to ensure strong-on-weak correctness; and Arancini, a complete and performant hybrid binary translator, implementing the verified mapping schemes for correctness.We evaluate Arancini using a multi-threaded benchmark suite with two backends (Arm and RISC-V), and show that Arancini can be up to 5× faster than QEMU - based translators while ensuring correctness and completeness.To our knowledge, Arancini is the first hybrid binary translator whose implementation is guided by formal proofs, to ensure correct execution of strong memory guests on weak memory hosts. It is also the first translator to address mixed-sized accesses for Arm targets.
Cage
Hardware-Accelerated Safe WebAssembly
WebAssembly (WASM) is an immensely versatile and increasingly popular compilation target. It executes applications written in several languages (e.g., C/C++) with near-native performance in various domains (e.g., mobile, edge, cloud). Despite WASM’s sandboxing feature, which isolates applications from other instances and the host platform, WASM does not inherently provide any memory safety guarantees for applications written in low-level, unsafe languages. To this end, we propose Cage, a hardware-accelerated toolchain for WASM that supports unmodified applications compiled to WASM and utilizes diverse Arm hardware features aiming to enrich the memory safety properties of WASM. Precisely, Cage leverages Arm’s Memory Tagging Extension (MTE) to (i) provide spatial and temporal memory safety for heap and stack allocations and (ii) improve the performance of WASM’s sandboxing mechanism. Cage further employs Arm’s Pointer Authentication (PAC) to prevent leaked pointers from being reused by other WASM instances, thus enhancing WASM’s security properties. We implement our system based on 64-bit WASM. We provide a WASM compiler and runtime with support for Arm’s MTE and PAC. On top of that, Cage’s LLVM-based compiler toolchain transforms unmodified applications to provide spatial and temporal memory safety for stack and heap allocations and prevent function pointer reuse. Our evaluation on real hardware shows that Cage incurs minimal runtime (< 5.8 %) and memory (< 5.3 %) overheads and can improve the performance of WASM’s sandboxing mechanism, achieving a speedup of over 5.1 %, while offering efficient memory safety guarantees.
Lasagne
A static binary translator for weak memory model architectures
The emergence of new architectures create a recurring challenge to ensure that existing programs still work on them. Manually porting legacy code is often impractical. Static binary translation (SBT) is a process where a program's binary is automatically translated from one architecture to another, while preserving their original semantics. However, these SBT tools have limited support to various advanced architectural features. Importantly, they are currently unable to translate concurrent binaries. The main challenge arises from the mismatches of the memory consistency model specified by the different architectures, especially when porting existing binaries to a weak memory model architecture. In this paper, we propose Lasagne, an end-to-end static binary translator with precise translation rules between x86 and Arm concurrency semantics. First, we propose a concurrency model for Lasagne's intermediate representation (IR) and formally proved mappings between the IR and the two architectures. The memory ordering is preserved by introducing fences in the translated code. Finally, we propose optimizations focused on raising the level of abstraction of memory address calculations and reducing the number of fences. Our evaluation shows that Lasagne reduces the number of fences by up to about 65%, with an average reduction of 45.5%, significantly reducing their runtime overhead.