About exporting symbols from an external module

[Le Tan]

Hello! I am writing a device driver module. I define some functions in the
module, for example print_record(). I am doing something in the kvm, so I
want to call print_record() in the file of kvm module, for example, I may
call print_record() in file /arch/x86/kvm/x86.c to put something into my
device driver module.
Now comes the question.
1. Where should I put the codes of my device driver module? It's the first
time I write the device driver.
2. After compiling my module, I encounter an error when I compile the kvm
module.
     ERROR: "print_record" [arch/x86/kvm/kvm.ko] undefined!
    I use EXPORT_SYMBOL(print_record) in my module file. I use "extern" to
declare print_record() and then call print_record()  in file x86.c.
    To solve this problem, I have tried to copy the Module.symvers from my
module folder to /arch/x86/kvm/. But it doesn't work. I have also tried to
add *KBUILD_EXTRA_SYMBOLS *to the Makefile of kvm. It doesn't work either.
    I cat /proc/kallsyms and find that the type of symbol "print_record" is
"t" ( local text). What should I do? How to call functions defined in my
own module from kvm? Maybe there is something wrong in Makefiles?

Any suggestion is appreciated!
Thanks!
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