How can I tell what is using a kernel module?

How can I tell what is using a kernel module?

You can try lsmod | grep to see all loaded kernel modules that are using a module. You can also try dmesg | grep to see if the kernel logs have any clues as to which processes may be using a module. You may be able to remove the module using rmmod –force .

How do kernel modules differ from system calls?

A kernel module registers itself in order to serve future requests. Kernel modules can be interrupted. An interrupt handler can request your driver at the same time that your driver is serving a system call. In a symmetric multiprocessor (SMP) system, your driver could be executing concurrently on more than one CPU.

What are the possible states for a module in the kernel?

There are 3 possible states for this field:

• Live.
• Loading.
• Unloading.

Is kernel module loaded?

Kernel modules are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system. To create a kernel module, you can read The Linux Kernel Module Programming Guide. A module can be configured as built-in or loadable.

What is a downloadable kernel module?

In computing, a loadable kernel module (LKM) is an object file that contains code to extend the running kernel, or so-called base kernel, of an operating system. LKMs are typically used to add support for new hardware (as device drivers) and/or filesystems, or for adding system calls.

Do loadable kernel modules have system call numbers?

Loadable module support within the Linux kernel facilitates the interception of system calls, and this feature can be taken advantage of as described within the examples below.

Is a system call a kernel function?

System Call is basically a request to Kernel from user to access some function. while kernel is a core part of OS which handles Process management , I/O management , memory management and File management.

How do I find my kernel module version?

1. Runtime method insmod /module_version.ko cat /sys/modules/module_version/version # => 1.0 cat /sys/module/module_version/srcversion # => AB0F06618BC3A36B687CDC5 modinfo /module_version.ko | grep -E ‘^(src|)version’ # => version: 1.0 # => srcversion: AB0F06618BC3A36B687CDC5.
2. /sys/modules/module_version/version.

Can a user program modify data inside the kernel?

If your user program could modify data inside the kernel directly, that would quickly lead to disaster. There’s only one conventional way for a user program to explicitly request services from the kernel – make a system call. There are also traps and some Linux-specific userland-kernel communication mechanisms, but those are not relevant here.

How is the user space interacting with the Linux kernel?

There is complete overview of linux-kernel module and user-space program interacting http://wiki.tldp.org/kernel_user_space_howto ” Kernel Space, User Space Interfaces ” by Ariane Keller (it is from 2008-09-28, but about 2.6 kernels; only major new way is relayfs)

How can a user request services from the kernel?

There’s only one conventional way for a user program to explicitly request services from the kernel – make a system call. There are also traps and some Linux-specific userland-kernel communication mechanisms, but those are not relevant here. As other posters have mentioned, there is a clear distinction between kernel and user space.