Linux Kernel Module: Memory and Per-Process RSS via /proc

This repository contains a Linux kernel module that exposes system-wide memory statistics and per-process Resident Set Size (RSS) through a custom /proc interface.

The module is intended purely for learning and exploration of Linux kernel internals, specifically memory accounting, process iteration, and /proc file implementation.

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What This Module Does

• Creates a virtual /proc entry at:

• Reports system memory information using si_meminfo():

• Total RAM

• Free RAM

• Used RAM

• Buffer memory

• Iterates over all user-space processes using for_each_process

• Displays for each process:

• PID

• Process name (comm)

• Resident Set Size (RSS) via get_mm_rss()

• Uses the seq_file interface for safe, scalable, multi-page output

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Kernel Concepts Reinforced

This module reinforces several fundamental Linux kernel concepts:

• Memory tracking through mm_struct
• Why kernel threads do not have an associated mm structure
• Dynamic generation of /proc entries (not stored on disk)
• Correct use of the seq_file API to avoid buffer overflows
• Safe iteration over the global task list

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Repository Structure

├── README.md ├── src/ │ ├── Makefile │ └── proc_mem_info.c └── LICENSE

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Build and Load

Build

cd src
make

Insert Module

sudo insmod proc_mem_info.ko

View Output

cat /proc/proc_mem_info


Kernel Logs

dmesg | tail


Remove Module

sudo rmmod proc_mem_info```


Notes

Secure Boot systems may block unsigned kernel modules.

Module signing using MOK keys may be required.

Kernel headers must match the running kernel (uname -r).

Disclaimer

This module is for educational purposes only.
Do not use on production systems.

Author

Amit Joshi