> Lukas Ruf <ruf@xxxxxxxxx> [2006-01-26 14:40]:
>
> However, there is "cosmetic" issue that annoys me: when I reference a
> symbol of another external module, an 'undefined' warning message is
> returned. Why?
>
>
> module_1
> - resides in its own directory structure
> - EXPORT_SYMBOL_GPL(a_required_function)
> - defines in module_1.h
> extern unsigned a_required_function(struct sk_buff *skb);
>
> module_2 resides in its own directory structure
> - resides in its own directory structure
> - requires "a_required_function"
> - includes "module_1.h"
>
> Compiling does not result in any error/warning.
>
> Linking module_1 does not result in any error/warning.
>
> Linking module_2 returns the warning:
> MODPOST
> *** Warning: "a_required_function" [path_to/module_2.ko] undefined!
>
I assume to have found the problem:
Defining the object files in Kbuild makes the Linux 2.6 Makefile
system run the modpost over all the object files defined there:
scripts/mod/modpost -m -i \
<path_to_linux>/Module.symvers vmlinux \
<path_to_module>/module_2.o \
<path_to_module>/module_2a.o \
<path_to_module>/module_2b.o
Since Kbuild includes only those objects in one directory, it
cannot find the symbol defined elsewhere.
Thus, it reports the problem because it cannot find the other
symbols.
If there was any possibility to include other objects the target
module depends on, the problem would be solved.
Can anyone confirm my "assumption"?
Thanks!
wbr,
Lukas
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