Wade Hampton wadehamptoniv@gmail.com x.x, 4/27/2016: Updated, added new example

The programs in this repository are examples of programming Linux kernel modules. The original versions were based on the The Linux Kernel Module Programming Guide from the Linux Doc Project (TLDP).

N/A (created 5/20/2013 some based on much earlier examples)

1. Linux Doc Project (TLDP): http://www.tldp.org/LDP/lkmpg/2.6/html/

2. Module Info: link:https://en.wikipedia.org/wiki/Loadable_kernel_module[]

3. Without listing the module as GPL, your kernel will be "tainted" which once set can only be reset on reboot:

   cat /proc/sys/kernel/tainted

4. The Makefile uses the kernel build system which gives a very simple syntax. Kernel build packages MUST be installed. Manual package build is not supported by the Makefile.

5. This contains modules with the older /proc interface and the newer one.

6. This may be expanded to include some examples of dynamic kernel module support (DKMS).

7. These notes will be expanded over time....

test1 very simple kernel module (taints kernel) hello-2 demonstrate module_init(), module_exit() macros hello-3 hello-2 plus license, author, description proc_fs-old /proc example, Linux 2.6 and earlier proc_new /proc example with jiffies using new /proc interface Linux 2.6.18 and later (CentOS 5 supported) jiffies /proc example with jiffies, deprecated /proc interface kthread sample kernel thread, uses old /proc (deprecated) kthread2 expanded kernel thread, uses old /proc (deprecated) kthread3 expanded kernel thread, new /proc interface crash_evens expanded seq_file example with proc data

• CentOS 5-7: src is in /usr/src/kernels/uname -r

• Ubuntu 14: src is in /usr/src/linux-headers-uname -r

• Make is via the Makefile: /lib/modules/uname -r/build/Makefile (This is the kernel build system and makes modules in the current dir).

  obj-y += abc.o -- include object in vmlinuz obj-m += abc.o -- include object as a module

• Typical make file rules to build abc.c as a module into abc.ko:

  obj-m += abc.o make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

• DKMS: link:http://xmodulo.com/build-kernel-module-dkms-linux.html[]