In the Linux system, there is a very special and important <span>virtual</span> shared library <span>linux-vdso.so.1</span>, where <span>vdso</span> stands for <span>Virtual Dynamic Shared Object</span>, meaning it is a virtual dynamic shared library. What makes it special? Simply put, it is a <span>"phantom"</span> shared library that is not on the hard disk, but is an <span>accelerator</span> code … Read more
Overview of System Calls A system call is the standard interface for user-space programs to interact with the operating system kernel. It provides the only legitimate way for user programs to access core functionalities such as hardware device access, process management, and file system operations. In Linux, system calls implement a secure switch between user … Read more
In this article (Implementing a PCIe Device in Qemu: Adding DMA Functionality), we added a vector addition feature to the PCIe device simulated with Qemu. This PCIe device uses DMA read operations to transfer the contents of two operand vectors provided by the driver into an internal buffer of the PCIe device, computes the sum … Read more
Introduction:When I first started working, a leader from another department often forgot the root password for his Linux testing environment and would ask me for help to bypass it. I could easily enter single user mode, reset the password, and reboot in about a minute. After leaving that company, I hardly used single user mode … Read more