👀 Views: 76 💬 Answers: 1 📅 Created: 2025-06-05

linux kernel centos c

I'm optimizing some code but I'm dealing with I'm relatively new to this, so bear with me. I'm trying to develop a custom kernel module on CentOS 8, but I'm working with an scenario where the module fails to load, and I receive an 'Unknown symbol' behavior. Here is the relevant part of my module code: ```c #include <linux/module.h> #include <linux/kernel.h> static int my_function(void) { printk(KERN_INFO "My function is called."); return 0; } MODULE_LICENSE("GPL"); MODULE_EXPORT(my_function); static int __init my_module_init(void) { printk(KERN_INFO "Loading my module..."); return 0; } static void __exit my_module_exit(void) { printk(KERN_INFO "Unloading my module..."); } module_init(my_module_init); module_exit(my_module_exit); ``` When I compile the module using `make` with the provided Makefile: ```makefile obj-m += my_module.o all: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules clean: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean ``` I don't see any errors during compilation, but when I try to load the module using `sudo insmod my_module.ko`, I get the following behavior: ``` insmod: behavior: could not insert module my_module.ko: Unknown symbol in module ``` I've verified that I'm running the correct kernel version and that the kernel headers are installed. I also double-checked that I exported the symbol `my_function`. This is what I see when I run `dmesg` right after attempting to load the module: ``` my_module: Unknown symbol my_function (err -2) ``` I've tried to resolve the scenario by ensuring that any dependencies for `my_function` are properly included, but I'm still hitting a wall. What could be causing this scenario, and how might I resolve it to successfully load my module? Thanks in advance! I've been using C for about a year now. Am I missing something obvious? I'm coming from a different tech stack and learning C. My development environment is Windows 11. Am I missing something obvious?