Add header files to the Linux kernel

Question

I recently created a new header file that I want to include in the Linux kernel. I put the .h file in usr/src/linux/include/linux. I put the .c file in usr/src/linux/lib. I updated the Makefile in the lib directory and recompiled the kernel, without error. However, when I tried to use the functions in the header file, I got an error saying that the functions were not defined. I assumed (wrongly) that the kernel would know which c file the header was for. How do I properly set this up?

How did you try to use the functions? In a C file that is part of your kernel? — Mircea
Yes. I included the header I added and tried to call the function inside a kernel c file that I added a few weeks back. — Gregory-Turtle

user1479326 user1479326 · Accepted Answer · 2012-06-25T11:41:08

Where you try to use the functions?

If tried your function within the kernel (external module). You need to add EXPORT_SYMBOL(); to the module where your function is defined.

Otherwise (from user-space) it is a different (and more complicated).

Add header files to the Linux kernel

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