exported module symbols and warnings

exported module symbols and warnings

[Scott Baker]

Hello,

I'm developing a pair of kernel modules. One module needs to export a
symbol that will be used by the second module. I'm doing this by using
EXPORT_SYMBOL(MySymbol) in the first module and declaring the symbol
as extern in the second module. It works fine.

However, there are a couple of warnings that I'm trying to clean up.
The first is when building the second module (the one that uses the
symbol). It is: "*** Warning: "MySymbol" [filename] undefined!"

The second warning occurs when insmod'ing the second module. It is:
"no version for "MySymbol" found: kernel tainted."

Can someone point me in the right direction? The modules are behaving
fine, but the warning messages are a bit unsightly.

I'm running RHEL4, kernel version 2.6.9-42.

Thanks,
Scott

Re: exported module symbols and warnings

[Sam Ravnborg]

On Mon, Oct 16, 2006 at 11:35:13AM -0700, Scott Baker wrote:
> Hello,
> 
> I'm developing a pair of kernel modules. One module needs to export a
> symbol that will be used by the second module. I'm doing this by using
> EXPORT_SYMBOL(MySymbol) in the first module and declaring the symbol
> as extern in the second module. It works fine.
> 
> However, there are a couple of warnings that I'm trying to clean up.
> The first is when building the second module (the one that uses the
> symbol). It is: "*** Warning: "MySymbol" [filename] undefined!"
> 
> The second warning occurs when insmod'ing the second module. It is:
> "no version for "MySymbol" found: kernel tainted."
> 
> Can someone point me in the right direction? The modules are behaving
> fine, but the warning messages are a bit unsightly.
Try to read Documentation/kbuild/modules.txt - here you will read that
the trick is to use a common kbuild file for both modules.

And that should fix your "no version" error too since you will
then know the version info during build time.

	Sam