Creating linked list in liinux Kernel using the list

Linked lists are a very frequently used data structure in the linux kernel and to make the programming easier the linux kernel provides an e...Read more »

Unknown symbol cfg80211_scan_done

The following errors might occur while working with wireless drivers for linux. Unknown symbol cfg80211_scan_done Unknown symbol ieee80211_...Read more »

Installing broadcom bcm43142 Wireless driver for linux

Most of the Linux distros do not have drivers for wireless bcm43142 wireless adapter. If your system has amd64 architecture then the driver ...Read more »

Creating a read write proc entry in kernel versions above 3.10

In the post Creating read only proc entry in kernel versions above 3.10 we saw how to create a read proc entry in the kernel version 3.10 a...Read more »

Creation of proc entry using proc_create_data in kernel version 3.10 and above.

In the post "Creating read only proc entry in kernel versions above 3.10 . " we saw how to create a proc entry using the function...Read more »

Creating read only proc entry in kernel versions above 3.10.

The creation of proc entries has undergone a considerable change in kernel version 3.10 and above. In this post we will see one of the metho...Read more »

Using Spinlock in linux : Example

In the post we see the various functions available for spinlock in Linux. Let us look at an example and see how it can be used in Linux. ...Read more »

Spinlocks in linux

We saw in the post " Introduction to spinlocks " how spinlock can be used to achieve mutual exclusion. Let us further look at the...Read more »

Introduction to spinlocks

Spinlocks are one of the ways of achieving mutual exclusion that is, preventing multiple processes from entering the critical section simult...Read more »

working of the fuction atomic_add_return

Atomic instructions are useful for executing instructions with out interrupt. Theory of the same is given in the post. Let us look into th...Read more »

modified scull code for 3.x.x

The scull code is the examples that the book, linux device drivers by Jonathan Corbet uses to explain the various concepts of character dev...Read more »

Implementing an ioctl call (for kernel versions above 2.6.39)

In the post " Creating an ioctl command in linux " we saw the basics of ioctl, and how we can create our own ioctl commands. The ...Read more »

Pointer to structure from its member pointer: container_of

In c programming, we use structures to store variables of different data types in one kind of variable. Each variable in the structure is te...Read more »

using printk_ratelimit

printk is used in kernel programming to log messages and is very useful while debugging the kernel programs. But the kernel log being tho...Read more »

printk and console log level.

printk is used in kernel programming to print messages into the kernel logs. The syntax of printk is printk ("log level" "m...Read more »

Unknown symbol find_task_by_pid_ns

You will come across this error Unknown symbol find_task_by_pid_ns if you are trying to write a module using the function find_task_by_...Read more »

Compiling linux kernel on debian

Here are the steps to compile a kernel from source in debian based systems. Note:These steps have worked successfully on debian 6.0 (linux 2...Read more »

Module to print the open files of a process

Linux maintains the information about the current process in a structure task_struct . A macro named current returns a pointer to the task...Read more »

The working of macros MAJOR,MINOR and MKDEV

In linux, every device under /dev is associated with two numbers "major number" and the minor number. Where the major number repr...Read more »

Creating a folder under /proc and creating a entry under the folder.

In the posts " creating proc read entry ", creating read/write proc entry we saw how to create read only proc entries and read wr...Read more »