How do applications interact with kernel?

Applications running on the system communicate with the kernel via system calls (see Figure 1.1). An application typically calls functions in a libraryfor example, the C librarythat in turn rely on the system call interface to instruct the kernel to carry out tasks on their behalf.

How does the Linux kernel work?

The Linux kernel mainly acts as a resource manager acting as an abstract layer for the applications. The applications have a connection with the kernel which in turn interacts with the hardware and services the applications. Linux is a multitasking system allowing multiple processes to execute concurrently.

How does user communicate with kernel?

The user application will be able to communicate with the kernel module and exchange data. The user application uses ioctl calls to send data to the kernel module. In the following example, these ioctl calls can be used to send application-specific details or send any updates at a later point of time.

How does the kernel interact with the hardware shell interact with the user?

Kernel is interface between hardware and shell. Kernel code is written for efficient working on hardware, files and interconnected devices. Shell is code written for user to interact with hardware.

Why is kernel needed in OS?

The kernel is the essential center of a computer operating system (OS). It is the core that provides basic services for all other parts of the OS. It is the main layer between the OS and hardware, and it helps with process and memory management, file systems, device control and networking.

How do you communicate between user and kernel space?

There are couple of well known methods to communicate from user space to kernel space.

1. Virtual file system like /proc , /sys , /configfs , /debugfs Standard.
2. system call like read() , write() , open() , close() , fork()
3. ioctl for char drivers.
4. netlink socket – mostly used by network subsystem.

What is netlink socket in Linux?

The Netlink socket family is a Linux kernel interface used for inter-process communication (IPC) between both the kernel and userspace processes, and between different userspace processes, in a way similar to the Unix domain sockets.

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