coverage-analysis

# Coverage Analysis Coverage analysis is essential for understanding which parts of your code are exercised during fuzzing. It helps identify fuzzing blockers like magic value checks and tracks the effectiveness of harness improvements over time. ## Overview Code coverage during fuzzing serves two critical purposes: 1. **Assessing harness effectiveness**: Understand which parts of your application are actually executed by your fuzzing harnesses 2. **Tracking fuzzing progress**: Monitor how coverage changes when updating harnesses, fuzzers, or the system under test (SUT) Coverage is a proxy for fuzzer capability and performance. While coverage [is not ideal for measuring fuzzer performance](https://arxiv.org/abs/1808.09700) in absolute terms, it reliably indicates whether your harness works effectively in a given setup. ### Key Concepts | Concept | Description | |---------|-------------| | **Coverage instrumentation** | Compiler flags that track which code paths are executed | | **Corpus coverage** | Coverage achieved by running all test cases in a fuzzing corpus | | **Magic value checks** | Hard-to-discover conditional checks that block fuzzer progress | | **Coverage-guided fuzzing** | Fuzzing strategy that prioritizes inputs that discover new code paths | | **Coverage report** | Visual or textual representation of executed vs. unexecuted code | ## When to Apply **Apply this technique when:** - Starting a new fuzzing campaign to establish a baseline - Fuzzer appears ...