Ubuntu Linux has been exposed to a critical vulnerability that affects systems running the 6.8.0-60-generic kernel version of Ubuntu 24.04.2. Local attackers can exploit this vulnerability to escalate privileges and ultimately gain root access on the affected systems. This vulnerability arises from an imbalance in reference counting within the af_unix subsystem, leading to a use-after-free … Read more
The Linux system consists of the following core components: Linux Kernel DefinitionThe kernel is the core of the operating system, responsible for managing hardware resources (such as CPU, memory, disk, network, etc.) and providing basic services to applications. Functions Process Management: Creating, scheduling, and terminating processes. Memory Management: Allocating and reclaiming memory. File System Management: … Read more
Tail calls A tail call is a mechanism that allows eBPF developers to split logic into multiple parts and jump from one part to another. Unlike traditional function calls, the control flow never returns to the code that initiated the tail call; it works more like a <span>goto</span> statement. To use tail calls, developers need … Read more
In-Depth Analysis of the Linux Virtual File System (VFS) 1 Overview and Historical Background of Linux VFS The Linux Virtual File System (VFS) is an extremely important subsystem within the Linux kernel. It serves as an abstraction layer for file systems, providing a unified file access interface for user-space applications while offering a standardized implementation … Read more
Functions When we refer to functions, we mean the functions you write in C or similar programming languages. In eBPF, the terms “function”, “program”, and “subroutine” are often used interchangeably. A program refers to a function with a single parameter (i.e., context), which can be attached to a hook point. A subroutine, also known as … Read more
Program types (Linux) eBPF programs can be used for a wide variety of purposes that are constantly expanding. To accommodate these different use cases, the kernel provides various types of eBPF programs. Since different types of programs execute in different locations within the kernel, the Linux kernel restricts or allows certain functionalities based on the … Read more
Daily interesting computer knowledge, today’s topic: Linux – start – The English pronunciation of Linux is /ˈlɪnəks/, which is phonetically similar to “林纳克斯” in Chinese. For those who are unsure of the pronunciation, you can listen to the standard pronunciation audio by its creator 📻 http://www.paul.sladen.org/pronunciation/torvalds-says-linux.wav The name Linux is a combination; the first part … Read more
Introduction Pulse Width Modulation (PWM) is a commonly seen feature in embedded systems. It is a highly effective technique that utilizes the digital output of a microprocessor to control analog circuits, widely applied in various fields ranging from measurement and communication to power control and conversion. The Rockchip PWM supports three modes: Continuous mode, One-shot … Read more
Process Perspective vs Kernel Perspective In a Linux system, we can understand the system’s operating mechanism from two different levels: Process Perspective and Kernel Perspective. These two perspectives have essential differences. Process Perspective: Limited “User Space” View From the process perspective, the system’s operation is filled with uncertainty and limitations: #include <stdio.h> #include <unistd.h> #include … Read more
What is it exactly? Linux-Insides is actually an open-source project repository that contains a continuously updated “Guide to the Linux Kernel Internals.” Think about it: when you type <span>ls</span> or <span>cat</span> in the system, what happens behind the scenes? This manual dissects the implementation details from bootloader, kernel decompression, scheduler, system calls, memory management, synchronization … Read more
