Coverage

🧭 Where we left off Welcome back to our technical journey on measuring binary test coverage! In part 4 we introduced funkoverage, a native, high-performance eBPF-based coverage tracer that leverages uprobe_multi to capture function entry events in GNU/Linux with less than 2% overhead. It parses static library dependencies using ldd during installation and maps uprobes to all discovered functions. But there was a big fat elephant in the room: dlopen(). Some of the most complex, modular software in the world — such as web servers with dynamic modules, plugin-based enterprise applications, and multi-protocol databases — load their dependencies at runtime on-the-fly. Because these libraries are not declared in the ELF binary’s DT_NEEDED header, they are invisible to ldd during installation. Today, we are going to chase the dynamic loading ghost, explore how we solved this with an elegant, highly scalable, event-driven eBPF JIT instrumentation strategy, and battle-test it live on standard, unmodified production binaries like Nginx and OpenSSL! ...

🧭 Where we left off Welcome back to our ongoing series on measuring test coverage for binary programs! In part 1 we used Go’s built-in -cover flag — clean and accurate, but only works if you own the source and can recompile. In part 2 we used valgrind and gdb to trace gzip without touching its source. In part 3 we explored Intel PIN, a proper dynamic binary instrumentation framework — powerful, but it came with a ~100MB proprietary C++ SDK and was limited to x86_64. ...

▶️ Intro : Let Me Be On the previous post we continued our journey with a more complex scenario, using a mix of gdb and valgrind to trace all the function execution inside a given binary. This time, hold on because we’re cranking up the complexity. We’ll dive deeper into low-level analysis and explore how to use Intel PIN, a powerful dynamic instrumentation framework for manipulating and inspecting executable code at runtime. (Photo by FURQAN KHURSHID) ...

▶️ Intro On the previous post we started our journey with a very simple scenario, and we used a nice feature of the Go programming language to get a measure of how much % of the target program our test is exercising. This time I am going to experiment a Proof of Concept about how we can obtain a test code coverage metric estimation for a normal binary program, without any recompilation. ...