How to call a function from another kernel module in a kernel module?

Question

I've written three kernel modules. A, B, C. B needs some functions from A and C also. How to achieve this. Please be code specific. Any help is appreciated.

Asblarf · Accepted Answer · 2014-03-20 18:28:16Z

1

Below the function implementation in A, export it:

#include "moduleA_header.h"

int foo(void)
{
    printk(KERN_NOTICE "Hi there!\n");
}
EXPORT_SYMBOL(foo);

Make sure that the prototype of your function is declared in a header file that you can include in module B. Also, make sure module A gets loaded before module B.

Just make sure that your include has the path right to the moduleA_header.h file.

edited Mar 20, 2014 at 18:28

answered Mar 20, 2014 at 18:10

Asblarf

4911 gold badge5 silver badges14 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

mlemboy Over a year ago

Could you please show me the directory structure. Should these modules be in same directory (and also header file too)?

Asblarf Over a year ago

@mahesh The modules don't need to be in the same directory. All you need for that to work is to be able to include the definition of int foo() into the code of your module B.

mlemboy Over a year ago

How to return character arrays? While compiling it says return address of local variable.

Asblarf Over a year ago

@mahesh I am afraid your last comment is beyond the scope of the original question.

mlemboy Over a year ago

So should I ask another question?

|

Collectives™ on Stack Overflow

How to call a function from another kernel module in a kernel module?

1 Answer 1

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related