Linux Kernel module calling a function in another module

Question

Is it possible for a function in a linux kernel module calling a function in another module ?

http://stackoverflow.com/questions/9820458/kernel-modules-develop/9820518#9820518 — Jeyaram, Feb 19 '16 at 12:11
Possible duplicate of [How to call exported kernel module functions from another module?](http://stackoverflow.com/questions/12311867/how-to-call-exported-kernel-module-functions-from-another-module) — Ciro Santilli OurBigBook.com, May 20 '17 at 12:29
I wonder why no one else mentioned this. EXPORT_SYMBOL and extern is not enough. In the Kbuild file of the module that is importing symbol, add a line KBUILD_EXTRA_SYMBOLS = /Module.symvers . This helps the importing module know what symbols will be imported. — Sadman Sakib, Jun 29 '23 at 19:51

score 2 · Accepted Answer · answered Feb 19 '16 at 07:04

2

Yes. Of course, the other kernel module must be loaded.

For an example, look at the USB code, which is implemented as a mullti-layer driver, with each layer in its own module.Reference link here.

answered Feb 19 '16 at 07:04

msc

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score 1 · Answer 2 · edited Mar 02 '23 at 20:39

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It is possible by using EXPORT_SYMBOL in Linux.

If one module has one function called etx_shared_func and one global variable called etx_count. This function and variable can be shared among with all the loadable modules using EXPORT_SYMBOL.

EXPORT_SYMBOL(etx_shared_func);
EXPORT_SYMBOL(etx_count);

edited Mar 02 '23 at 20:39

avariant

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answered Feb 24 '23 at 12:15

Anshu Gaur

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Linux Kernel module calling a function in another module

2 Answers2