A kernel module is a run-time loadable object file that is loaded into operating system kernel to add functionality to a running kernel. Examples include device drivers and other kernel items.
Questions tagged [kernel-module]
2005 questions
107
votes
2 answers
Read/write files within a Linux kernel module
I know all the discussions about why one should not read/write files from kernel, instead how to use /proc or netlink to do that. I want to read/write anyway. I have also read
Driving Me Nuts - Things You Never Should Do in the Kernel.
However, the…
![](../../users/profiles/41889.webp)
Methos
- 10,908
- 11
- 41
- 47
76
votes
7 answers
Is there a way to figure out what is using a Linux kernel module?
If I load a kernel module and list the loaded modules with lsmod, I can get the "use count" of the module (number of other modules with a reference to the module). Is there a way to figure out what is using a module, though?
The issue is that a…
![](../../users/profiles/28804.webp)
mipadi
- 359,228
- 81
- 502
- 469
54
votes
5 answers
How to recompile just a single kernel module?
Usually kernel source are stored in /usr/src/linux-2.6.x/.
To avoid to recompile the entire kernel if I modify a module's source, how can I recompile just that module?
![](../../users/profiles/1056635.webp)
user1056635
- 735
- 2
- 9
- 12
49
votes
3 answers
How do I configure modprobe to find my module?
I'm trying to get a kernel module to load at boot.
If I run insmod /path/to/module.ko, it works fine. But this has to be repeated every time I reboot.
If I run modprobe /path/to/module.ko, it can't find the module.
I know modprobe uses a…
![](../../users/profiles/13652.webp)
sep332
- 950
- 2
- 12
- 24
42
votes
2 answers
What is the opposite of `mknod`?
I am learning to write character device drivers from the Kernel Module Programming Guide, and used mknod to create a node in /dev to talk to my driver.
However, I cannot find any obvious way to remove it, after checking the manpage and observing…
![](../../users/profiles/391161.webp)
merlin2011
- 63,368
- 37
- 161
- 279
33
votes
6 answers
Cross compiling a kernel module
I'm trying to cross compile a helloworld kernel (2.6.x) module for ARM architecture on my intel x86 host.
The codesourcery tool chain for ARM is located at: /home/ravi/workspace/hawk/arm-2009q3
The kernel source is located at…
![](../../users/profiles/319063.webp)
itisravi
- 3,166
- 3
- 20
- 28
32
votes
4 answers
What is a Kernel thread?
i am just started coding of device driver and new to threading, went through many documents for getting an idea about threads. i still have some doubts.
what is a kernel thread ?.
how it differs from user thread ?.
what is the relationship…
![](../../users/profiles/1085569.webp)
tijin
- 657
- 1
- 6
- 12
28
votes
4 answers
kvm: module verification failed: signature and/or required key missing - tainting kernel
I'm using Ubuntu 14.04 LTS and kernel version 3.13.11.4. I'm trying to load patched KVM modules kvm and kvm-intel and I'm getting the following errors
kvm: module verification failed: signature and/or required key missing - tainting kernel
…
![](../../users/profiles/2759261.webp)
user2743
- 1,303
- 1
- 17
- 31
27
votes
6 answers
How to compile a kernel module for Raspberry pi?
I'm having trouble compiling a kernel module for a raspberry pi. I want to compile a "hello world" kernel module using the raspberry pi itself.
I am using raspbian wheezy 3.6.11+.
I tried following the directions at…
![](../../users/profiles/3025582.webp)
user3025582
- 319
- 1
- 4
- 8
25
votes
2 answers
Difference between printk and pr_info
What's the exact difference between printk and pr_info functions ? And under what conditions, should I choose one over the another ?
![](../../users/profiles/4806357.webp)
Jarvis
- 8,020
- 3
- 23
- 51
23
votes
5 answers
linux kernel module linker warnings: "*** Warning: [] undefined!" - any way to get rid of them?
While compiling Linux kernel modules that depend on each other, linker gives undefined symbol warnings like
Building modules, stage 2.
MODPOST
*** Warning: "function_name1" [module_name] undefined!
*** Warning: "function_name2" [module_name]…
![](../../users/profiles/68091.webp)
Gary
- 321
- 1
- 2
- 8
22
votes
2 answers
How to find the list of processes using a particular kernel module?
When I try to rmmod a module I get the error message "Error: Module in use" , lsmod | grep shows the count.
Is there a way that would tell me which processes are using this particular kernel module/driver?
![](../../users/profiles/1172880.webp)
Raj
- 309
- 2
- 4
- 13
22
votes
3 answers
How to stop Linux kernel threads on rmmod?
I wrote the following code to create a kernel thread:
#include
#include
#include
#include
#include
struct task_struct *task;
int data;
int ret;
int thread_function(void…
![](../../users/profiles/585919.webp)
pradeepchhetri
- 2,688
- 6
- 26
- 45
21
votes
5 answers
How to load Linux kernel modules from C code?
I have an application that has both two external kernel modules and a userspace daemon. I want to load the modules from the daemon code, written in C, at startup, and unload them on clean exit. Can I load them in a cleaner way than doing…
![](../../users/profiles/285272.webp)
Prof. Moriarty
- 491
- 1
- 4
- 9
21
votes
5 answers
How to get current hour (time of day) in linux kernel space
I'm writing a kernel module that checks to see if the time is between two specified hours, and disables input if it is. This has to do with me wanting to make sure I go to bed early. (I know I could also use any number of different techniques…
![](../../users/profiles/326154.webp)
Tom Macdonald
- 5,763
- 7
- 36
- 56