Mastering the Linux Kernel: A Practical Guide to Internals and Module Development

Stop writing user-space code. It is time to dive into the deep end. Mastering the Linux Kernel is not a theoretical textbook. It is a hands-on manual for the engineers who build the world's infrastructure. From the moment you boot your first custom kernel to the deployment of a stealth rootkit detector, this book demands that you get your hands dirty. Written for C programmers who understand the basics of operating systems, this guide bridges the gap between abstract concepts and the cold, hard reality of hardware interaction. You will not just read about the Completely Fair Scheduler; you will analyze its Red-Black tree implementation. You will not just learn about memory management; you will build a high-performance circular buffer driver using direct memory mapping. Topics covered include: Foundation & Architecture: Building a professional kernel development environment with QEMU and BusyBox, and mastering Loadable Kernel Modules (LKM). Core Internals: Deep dives into the Slab allocator, the Buddy system, interrupt handling (Top/Bottom halves), and the CFS scheduler. Concurrency & Safety: Writing race-free code using Spinlocks, Mutexes, and the Read-Copy-Update (RCU) mechanism. Device Drivers: Creating robust character drivers, handling blocking I/O, managing I/O ports, and mastering DMA transfers. Networking: Dissecting the sk_buff structure, implementing NAPI for high-load throughput, and writing Netfilter hooks. Modern Observability: Utilizing eBPF and XDP for high-speed packet filtering and dynamic system tracing without recompilation. Security: A full practical guide to building a kernel rootkit detector to identify syscall hooks and hidden processes. This book respects your intelligence and your time. It focuses on the code that powers modern Linux systems, covering v6.x kernels and the latest tooling. Whether you are debugging a deadlock in a production driver or architecting a new embedded system, this is the reference you will keep open on your desk. Master the machine. Control the kernel.