Linux Kernel

Telephone Book

Installation

Compile and install Kernel module

./init.sh

Execute command for identify Major

cat /proc/devices | grep chardev | awk '{print $1}'

Create symbol device

mknod /dev/chardev c <Major> 0

Compile user-space program for communicate with module

gcc system_func.c -o run

Usage

./run add_user <name> <surname> <age> <email> <phone>
./run get_user <surname>
./run del_user <surname>

Check module output

dmesg

Keyboard interrupt handler

Run

Execute command

./init.sh

Check module output

dmesg

You should see the counter of pressed keyboard key

Schedule process counter and save to procfs

Apply patch for vmlinuz-6.4.0-rc3-dirty and check proc folder. You should find something like this - /proc/<xxx>/schedule_counter where store counter number of task_struct field

Light way

tar xzf linux6.4.0.tar.gz

Run VM with kernel

emu-system-x86_64 -kernel ./build/vmlinuz-6.4.0-rc3-dirty \
                  -m 512m \
                  -initrd ./build/initramfs.gz \ 
                  -nographic \
                  -append "console=ttyS0" \ 
                  --cpu host \
                  --enable-kvm

Check /proc space with /proc/<xxx>/schedule_counter