16 entries tagged with #Code Coverage

by Paul Butcher

Finding Vulnerabilities using Advanced Fuzz testing and AFLplusplus v3.0

Some of you may recall an AdaCore blog post written in 2017 by Thales engineer Lionel Matias titled "Leveraging Ada Run-Time Checks with Fuzz Testing in AFL". This insightful post took us on a journey of discovery as Lionel demonstrated how Ada programs, compiled using GNAT Pro and an adapted assembler pass can be subjected to advanced fuzz testing. In order to achieve this Lionel demonstrated how instrumentation of the generated assembly code around jump and label instructions, could be subjected to grey-box (path aware) fuzz testing (using the original AFL v2.52b as the fuzz engine). Lionel explained how applying the comprehensive spectrum of Ada runtime checks, in conjunction with Ada's strong typing and contract based programming, enhanced the capabilities of fuzz testing beyond the abilities of other languages. Ada's advanced runtime checking, for exceptions like overflows, and the scrutiny of Ada's design by contract assertions allow corner case bugs to be found whilst also utilising fuzz testing to verify functional correctness.

by Pierre-Marie de Rodat

GNATcoverage: getting started with instrumentation

This is the second post of a series about GNATcoverage and source code instrumentation. The previous post introduced how GNATcoverage worked originally and why we extended it to support source instrumentation-based code coverage computation. Let’s now see it in action in the most simple case: a basic program running on the host machine, i.e. the Linux/Windows machine that runs GNATcoverage itself.

#GNATcoverage

by Pierre-Marie de Rodat

Introducing source code instrumentation in GNATcoverage

This is the first post of a series about GNATcoverage and source code instrumentation.In order to make GNATcoverage viable in more contexts, we planned several years ago to add instrumentation support in GNATcoverage for Ada sources. This feature reached maturation recently and is available in the last Continuous Release, so it is a good time to present it with a blog series!

#GNATcoverage

by Lionel Matias

Leveraging Ada Run-Time Checks with Fuzz Testing in AFL

Fuzzing is a very popular bug finding method. The concept, very simple, is to continuously inject random (garbage) data as input of a software component, and wait for it to crash. If, like me, you find writing robustness test tedious and not very efficient in finding bugs, you might want to try fuzzing your Ada code.Here's a recipe to fuzz-test your Ada code, using American Fuzzy Lop and all the runtime checks your favorite Ada compiler can provide.Let's see (quickly) how AFL works, then jump right into fuzzing 3 open-source Ada libraries: ZipAda, AdaYaml, and GNATCOLL.JSON.

#Testing #Ada #VerificationTools

by Fabien Chouteau

Ada on the first RISC-V microcontroller

Updated July 2018

#Embedded Development #Ada #RISC-V

by Yannick Moy

Research Corner - FLOSS Glider Software in SPARK

Two years ago, we redeveloped the code of a small quadcopter called Crazyflie in SPARK, as a proof-of-concept to show it was possible to prove absence of run-time errors (no buffer overflows, not division by zero, etc.) on such code. The researchers Martin Becker and Emanuel Regnath have raised the bar by developing the code for the autopilot of a small glider in SPARK in three months only. Their paper and slides are available, and they have released their code as FLOSS for others to use/modify/enhance!

#Formal Verification #Dev Projects #SPARK

by Yannick Moy

Frama-C & SPARK Day Slides and Highlights

The Frama-C & SPARK Day this week was a very successful event gathering the people interested in formal program verification for C programs (with Frama-C) and for Ada programs (with SPARK). Here is a summary of what was interesting for SPARK users. We also point to the slides of the presentations.

#SPARK

by Yannick Moy

(Many) More Low Hanging Bugs

We reported in a previous post our initial experiments to create lightweight checkers for Ada source code, based on the new Libadalang technology. The two checkers we described discovered 12 issues in the codebase of the tools we develop at AdaCore. In this post, we are reporting on 6 more lightweight checkers, which have discovered 114 new issues in our codebase. This is definitely showing that these kind of checkers are worth integrating in static analysis tools, and we look forward to integrating these and more in our static analyzer CodePeer for Ada programs.

#Static Analysis #Libadalang

by Pierre-Marie de Rodat

GNATcoverage moves to GitHub

Following the current trend, the GNATcoverage project moves to GitHub! Our new address is: https://github.com/AdaCore/gnatcoverage

#GitHub #GNATcoverage

by Emmanuel Briot

Integrate new tools in GPS

This blog, the first in a series, explains the basic mechanisms that GPS (the GNAT Programming Studio) provides to integrate external tools. A small plugin might make your daily workflow more convenient by providing toolbar buttons and menus to spawn your tool and parse its output.

#GPS

by AdaCore Admin

VectorCAST/Ada: Ada 2012 Language Support

We are pleased to announce that on April 27th our partner, Vector, will host a webinar to showcase their latest VectorCAST/Ada release!

by AdaCore Admin

Provably safe programming at Embedded World

AdaCore continues to build reliable and secure software for embedded software development tools. Last month, we attended Embedded World 2016, one of the largest conferences of its kind in Europe, to present our embedded solutions and our expertise for safety, and mission critical applications in a variety of domains.

#ARM #emb2016 #embedded #Embedded World

by Yannick Moy

Formal Verification of Legacy Code

Just a few weeks ago, one of our partners reported a strange behavior of the well-known function Ada.Text_IO.Get_Line, which reads a line of text from an input file. When the last line of the file was of a specific length like 499 or 500 or 1000, and not terminated with a newline character, then Get_Line raised an exception End_Error instead of returning the expected string. That was puzzling for a central piece of code known to have worked for the past 10 years! But fair enough, there was indeed a bug in the interaction between subprograms in this code, in boundary cases having to do with the size of an intermediate buffer. My colleague Ed Schonberg who fixed the code of Get_Line had nonetheless the intuition that this particular event, finding such a bug in an otherwise trusted legacy piece of code, deserved a more in depth investigation to ensure no other bugs were hiding. So he challenged the SPARK team at AdaCore in checking the correctness of the patched version. He did well, as in the process we uncovered 3 more bugs.

#SPARK #Legacy #Formal Methods

by Jamie Ayre

Verification on Ada code with Static and Dynamic Code Analysis - Webinar

One of the main challenges to get certification in Ada projects is the achievement of 100% code coverage but in most projects an amount of more than 95% structural coverage is hard to achieve. What can you do with the last 5% of code that can't be covered? DO-178C for example, provides a framework for the integration of various techniques in the development process to solve the problem. In this webinar you learn how static analysis and dynamic testing can help complete analysis for pieces of code that are not covered.

#CodePeer #Code Coverage #Dynamic Analysis #Static Analysis #DO-178 #DO-178C