Symbolic and analytic techniques for resource analysis of Java bytecode

Recent work in resource analysis has translated the idea of amortised resource analysis to imperative languages using a program logic that allows mixing of assertions about heap shapes, in the tradition of separation logic, and assertions about consumable resources. Separately, polyhedral methods have been used to calculate bounds on numbers of iterations in loop-based programs. We are attempting to combine these ideas to deal with Java programs involving both data structures and loops, focusing on the bytecode level rather than on source code

Prototype on FreeRTOS and RISC-V of the application software of the EPD ICU onboard Solar Orbiter

Solar Orbiter es un ambicioso proyecto desarrollado por la Agencia Espacial Europea que tiene como objetivo investigar más cercanamente nuestro sol. La ICU de su instrumento EPD corre su software de aplicación en RTEMS, el cual se ha demostrado que es confiable. Sin embargo, podemos tratar de mejorarlo desarrollando un puerto en FreeRTOS, el cual es más popular y puede proporcionar más escalabilidad. Este software correrá en una novedosa arquitectura llamada RISC-V. Para lograr esto, construiremos un prototipo y lo probaremos en la placa RV32M1-VEGA desarrollada por OpenISA.Solar Orbiter is an ambitious project developed by the European Space Agency which aims to investigate our sun more closely. Its Energetic Particle Detector ICU runs its application software with RTEMS, which is proven to be reliable. However, we aim to potentially improve it by building a port in FreeRTOS, which is a more popular and scalable RTOS and testing this software in a modern hardware architecture called RISC-V which is lightweight and fast. To do this, we will build a prototype and test it in the RV32M1-VEGA board developed by OpenISA.Grado en Ingeniería Informátic

UPC++ v1.0 Programmer’s Guide, Revision 2020.3.0

UPC++ is a C++11 library that provides Partitioned Global Address Space (PGAS) programming. It is designed for writing parallel programs that run efficiently and scale well on distributed-memory parallel computers. The PGAS model is single program, multiple-data (SPMD), with each separate constituent process having access to local memory as it would in C++. However, PGAS also provides access to a global address space, which is allocated in shared segments that are distributed over the processes. UPC++ provides numerous methods for accessing and using global memory. In UPC++, all operations that access remote memory are explicit, which encourages programmers to be aware of the cost of communication and data movement. Moreover, all remote-memory access operations are by default asynchronous, to enable programmers to write code that scales well even on hundreds of thousands of cores

Micro Virtual Machines: A Solid Foundation for Managed Language Implementation

Today new programming languages proliferate, but many of them suffer from poor performance and inscrutable semantics. We assert that the root of many of the performance and semantic problems of today's languages is that language implementation is extremely difficult. This thesis addresses the fundamental challenges of efficiently developing high-level managed languages. Modern high-level languages provide abstractions over execution, memory management and concurrency. It requires enormous intellectual capability and engineering effort to properly manage these concerns. Lacking such resources, developers usually choose naive implementation approaches in the early stages of language design, a strategy which too often has long-term consequences, hindering the future development of the language. Existing language development platforms have failed to provide the right level of abstraction, and forced implementers to reinvent low-level mechanisms in order to obtain performance. My thesis is that the introduction of micro virtual machines will allow the development of higher-quality, high-performance managed languages. The first contribution of this thesis is the design of Mu, with the specification of Mu as the main outcome. Mu is the first micro virtual machine, a robust, performant, and light-weight abstraction over just three concerns: execution, concurrency and garbage collection. Such a foundation attacks three of the most fundamental and challenging issues that face existing language designs and implementations, leaving the language implementers free to focus on the higher levels of their language design. The second contribution is an in-depth analysis of on-stack replacement and its efficient implementation. This low-level mechanism underpins run-time feedback-directed optimisation, which is key to the efficient implementation of dynamic languages. The third contribution is demonstrating the viability of Mu through RPython, a real-world non-trivial language implementation. We also did some preliminary research of GHC as a Mu client. We have created the Mu specification and its reference implementation, both of which are open-source. We show that that Mu's on-stack replacement API can gracefully support dynamic languages such as JavaScript, and it is implementable on concrete hardware. Our RPython client has been able to translate and execute non-trivial RPython programs, and can run the RPySOM interpreter and the core of the PyPy interpreter. With micro virtual machines providing a low-level substrate, language developers now have the option to build their next language on a micro virtual machine. We believe that the quality of programming languages will be improved as a result

Bypassing Modern CPU Protections With Function-Oriented Programming

Over the years, code reuse attacks such as return-oriented programming (ROP) and jump-oriented programming (JOP) have been a primary target to gain execution on a system via buffer overflow, memory corruption, and code flow hijacking vulnerabilities. However, new CPU-level protections have introduced a variety of hurdles. ARM has designed the “Pointer Authentication” and “Branch Target Identification” mechanisms to handle the authentication of memory addresses and pointers, and Intel has followed through with its Shadow Stack and Indirect Branch Targeting mechanisms, otherwise known as Control-Flow Enforcement Technology. As intended, these protections make it nearly impossible to utilize regular code reuse methods such as ROP and JOP. The inclusion of these new protections has left gaps in the system\u27s security where the use of function-based code reuse attacks are still possible. This research demonstrates a novel approach to utilizing Function-Oriented Programming (FOP) as a technique to utilize in such environments. The design and creation of the “FOP Mythoclast” tool to identify FOP gadgets within Intel and ARM environments demonstrates not only a proof of concept (PoC) for FOP, but further cements its ability to thrive in diverse constrained environments. Additionally, the demonstration of FOP within the Linux kernel showcases the ability of FOP to excel in complex and real-world situations. This research concludes with potential solutions for mitigating FOP without adversely affecting system performance