How Linux Maps Hardware to Kernel Drivers
Use lspci, lsusb, lsmod, modinfo, and sysfs to identify bound, loaded, built-in, and missing Linux drivers, then trace probe failures with confidence.
Tag: Linux kernel
Linux on Surface Book: Install the Right Kernel First
The linux-surface kernel makes Surface Book hardware work on Linux. Learn which patches you need, how to verify installation, and what still breaks.
Why Apt Autoremove Leaves Old Kernels Behind
apt autoremove only removes auto-installed kernels. Learn why manual installs, held packages, and the running kernel stay behind, and how to safely purge them.
Kernel Panic Explained: Causes, Clues, and Fixes
A kernel panic stops Linux when recovery is unsafe. Learn to read its messages and trace faults to drivers, hardware, storage, or boot files.
SIGUSR1 Default Action: Why Signals Terminate Processes
SIGUSR1 defaults to terminating processes with no core dump. Learn why POSIX chose this behavior, how to install handlers, and debug unexpected signal deaths.
How Linux File Descriptors Work: The Three-Layer Model
File descriptors are per-process integers that index into a three-layer table structure. Learn how the kernel connects descriptors to open files and inodes.
Linux Process Life Cycle: States, Signals, and Diagnosis
Linux processes cycle through R, S, D, and T states. Learn to read /proc, use strace, and diagnose stuck tasks without guessing or killing blindly.
Build eBPF on ARM: Check the Kernel Before Clang
eBPF portability depends on the target kernel, not just the CPU. This guide covers clang, libbpf, CO-RE, BTF, verifier checks, and ARM loading.
Linux System Calls Tutorial: A Step-by-Step Guide
Have you ever wondered how a user program actually reaches the kernel to do privileged work? I set the goal for this tutorial: show how a program crosses the CPU boundary, what the kernel does next, and how you can verify behavior with tracing tools. I explain what you will be able to do by […]
Use eBPF to Trace VPN Traffic Across Encryption
The right eBPF hooks expose plaintext on tun0 or wg0 and ciphertext on the NIC, with practical guidance on correlation, probes, and failure diagnosis.
XDP SYN Flood Protection: Building eBPF Defenses
Build an eBPF XDP program that stops SYN floods at the NIC driver with per-IP rate limiting, hash maps, and line-rate packet drops before the kernel stack.
CVE-2013-6282 Fix: ARM Kernel Bounds Check Patch
CVE-2013-6282 has been patched in upstream kernels for over a decade. Learn why scanners still flag it and how to confirm your system is actually fixed.
Block IP Addresses With eBPF: XDP Attach Syntax
Load and attach XDP programs to network interfaces using bpftool and ip link pinned syntax. Master the two-step process: pin first, then attach to eth0.
Linux Kernel GPL-2.0 License: Official Documentation
GPL-2.0 governs the Linux kernel. Find the authoritative license text in COPYING and LICENSES/preferred/GPL-2.0, plus what compliance actually requires.
Linux Kernel Updates Without Reboot: Live Patch vs Reboot
Live patching fixes CVEs in place without rebooting, but kernel version upgrades need kexec or a restart. Learn which tool solves your actual problem.
What Kernel Times Mean and How to Fix Them
Kernel times show OS overhead on your CPU. Learn what drives them high, how to spot driver problems in Task Manager, and the tools to diagnose the real culprit.
Linux Kernel Version History: From 0.01 to 7.X
The Linux kernel’s journey from 0.01 to 7.X puts modern release strings in context, with commands for checking the version actually running on Ubuntu.
Automatic Linux Kernel Upgrades: Setup Guide
Set up automatic Linux kernel upgrades safely with unattended-upgrades or live patching. Learn when to automate, how to verify updates, and rollback strategies.
Enable Kernel CONFIG Options: What to Know First
Stop looking for CONFIG_HAVE_EBPF_JIT in menuconfig. Stop looking for CONFIG HAVE EBPF JIT in menuconfig. It describes a marker, not a feature you switch on.
LKML Guide: Read the Linux Kernel Mailing List Right
LKML is where kernel patches get reviewed and merged. Learn to search lore.kernel.org, report bugs correctly, and follow threads to actual fixes.
Linux Kernel Modules: Load, Unload, and Troubleshoot
Master kernel modules with lsmod, modprobe, and dmesg. Learn to load drivers, manage dependencies, and fix load failures without rebooting your system.
How to Update Linux Kernel Safely by Distro
Update your Linux kernel using apt, dnf, pacman, or zypper depending on your distribution. Learn the right command and why rebooting matters.
Linux Poll() vs Epoll: When to Use Each Syscall
poll() works for small file descriptor sets with POSIX compatibility; switch to epoll at scale. Learn when each syscall fits and common pitfalls to avoid.