Task Suspension with a Timeout in Ravenscar/Jorvik

This blog entry shows how to define an abstract data type that allows tasks to block on objects of the type, waiting for resumption signals from other components, for at most a specified amount of time per object. This "timeout" capability has been available in Ada from the beginning, via select statements containing timed entry calls. But what about developers working within the Ravenscar and Jorvik tasking subsets? Select statements and timed calls are not included within either profile. This new abstraction will provide some of the functionality of timed entry calls, with an implementation consistent with the Ravenscar and Jorvik subsets.

#Ada    #Tasking    #Ravenscar    #Jorvik    #Timeouts    #Timing_Event    #Suspension_Object   

When the RISC-V ISA is the Weakest Link

NVIDIA has been using SPARK for some time now to develop safety- and security-critical firmware applications. At the recent DEF CON 29, hackers Zabrocki and Matrosov presented how they went about attacking NVIDIA firmware written in SPARK but ended up attacking the RISC-V ISA instead!Zabrocki starts by explaining the context for their red teaming exercise at NVIDIA, followed by a description of SPARK and their evaluation of the language from a security attack perspective. He shows how they used an extension of Ghidra to decompile the binary code generated by GNAT and describes the vulnerability they identified in the RISC-V ISA thanks to that decompilation. Matrosov goes on to explain how they glitched the NVIDIA chip to exploit this vulnerability. Finally, Zabrocki talks about projects used to harden RISC-V platforms.

#Security    #SPARK    #RISC-V   

Security-Hardening Software Libraries with Ada and SPARK

Part of AdaCore's ongoing efforts under the HICLASS project is to demonstrate how the SPARK technology can play an integral part in the security-hardening of existing software libraries written in other non-security-oriented programming languages such as C. This blog post presents the first white paper under this work-stream, “Security-Hardening Software Libraries with Ada and SPARK”.

#SPARK    #STM32    #Embedded   

SPARKNaCl with GNAT and SPARK Community 2021: Port, Proof and Performance

This post continues our adventures with SPARKNaCl - our verified SPARK version of the TweetNaCl cryptographic library. This time, we'll be looking at yet more performance improvement via proof-driven "operator narrowing", porting the library to GNAT Community 2021, and the effect that has on proof and performance of the code.

#SPARK     #Cryptography    #Formal Verification    #Code generation    #RISC-V    #Security   

Going beyond Ada 2022

As we've seen previously in Ada 2022 support in GNAT, the support for Ada 2022 is now mostly there for everyone to take advantage of. We're now crossing fingers for this new revision to be officially stamped by ISO in 2022.

#Ada 2022   

An Introduction to Jorvik, the New Tasking Profile in Ada 2022

The Ada 2022 draft defines a new tasking profile named Jorvik (pronounced “Yourvick”), based directly on the standard Ravenscar profile. Jorvik relaxes certain restrictions in order to increase expressive power for real-time/embedded Ada and SPARK applications. We will explore the details in this blog entry.

#Ada Tasking Profiles    #Jorvik    #Ravenscar    #Ada 2022    #Real-Time    #Embedded   

On the Benefits of Families ... (Entry Families)

Ada has a concurrency construct known as “entry families” that, in some cases, is just what we need to express a concise, clear solution.

#Ada    #Concurrency    #Entry Families   

Showing Global contracts with GNAT Studio

In the integrated development environment, GNAT Studio, there is now a plugin that inserts the generated Global contracts inline with the code.

#GNAT Studio    #SPARK    #Contracts   

Doubling the Performance of SPARKNaCl (again...)

Following my last blog entry, further experiments show how the performance of SPARKNaCl can be doubled (again), plus analysis of worst-case stack usage and code size at all optimization levels.

#SPARK    #Cryptography    #Formal Verification    #Code generation    #RISC-V    #Security   

Performance analysis and tuning of SPARKNaCl

This blog goes into the details of both measuring and improving the runtime performance of SPARKNaCl on a real "bare metal" embedded target, and comparing results with those for the original "TweetNaCl" C implementation.

#SPARK    #Cryptography    #Formal Verification    #Code generation    #RISC-V    #Security   

#Security