Operating Systems Code

This repository contains implementations of fundamental operating systems concepts, organized into five main areas.

Directory Structure

kernel-security/

Linux kernel modules for security monitoring. Includes:

• process_monitor.c — Kprobe-based process creation monitor (fork/execve hooking)
• syscall_integrity.c — Syscall table integrity checker for rootkit detection

Demonstrates kernel-level introspection, the foundation for VMI (Virtual Machine Introspection) and host-based intrusion detection.

processes and scheduling/

Process management and CPU scheduling algorithms. Covers process creation with fork(), process hierarchies, and various scheduling strategies including priority scheduling, FCFS, SJF, and Round Robin.

Concurrency and locks/

Synchronization primitives and lock implementations. Includes ticket-based locks (spin and yield variants), queue locks, semaphore-based locks, and a parallel Monte Carlo pi calculator demonstrating practical concurrency patterns.

memory virtualization/

Virtual memory implementation with address translation and page replacement. Simulates MMU behavior with TLB lookups, page table walks, and replacement algorithms (FIFO, LRU, Clock).

Producer and dining Philosophy/

Classic concurrency problems and their solutions. Implements producer-consumer using both condition variables and semaphores, plus dining philosophers solutions that prevent deadlock.

Building

Each directory contains its own compile script:

cd <directory>
./compile.sh

Alternatively, use CMake in any directory.

Topics Covered

• Kernel Development: Loadable kernel modules, kprobes, syscall hooking
• Security Monitoring: Process auditing, rootkit detection, integrity checking
• Process Management: fork, waitpid, process hierarchies
• CPU Scheduling: Priority, FCFS, SJF, Round Robin
• Synchronization: Locks, semaphores, condition variables
• Concurrency Patterns: Parallel computation, shared state protection
• Virtual Memory: Address translation, TLB, page tables, page replacement
• Classic Problems: Producer-consumer, dining philosophers, deadlock prevention

Purpose

These implementations demonstrate core OS concepts through working code. Each directory's README contains additional details about the specific programs and what they illustrate.