can not resolve global kernel variable.

Eugene Goubine egoubine at gmail.com
Tue Feb 19 16:43:16 UTC 2008


Kyle, thanks for reffering,but it seems like GPL is not the case.
I want to write a module to track netdevices present.
Sort of a protocol sitting there. It is GPL'ed, but register_pm_notifier
usage ( as you can see in sources)
gives linker warning "pm_chain_head undefined",since register_pm_notifier is
"static inline" and expanded
to blocking_notifier_chain_unregister(&pm_chain_head, nb).
Why do you say pm_chain_head is static there ? Is it because it is not
exported by EXPORT_SYMBOL ?
So what does it have to do with the license ( which is already GPL, but I
just do not understand ).
What should be my choices, if I want to stay within distro kernel.
Thanks a lot.



On Feb 19, 2008 5:53 PM, Kyle McMartin <kyle at mcmartin.ca> wrote:

>  On Tue, Feb 19, 2008 at 01:41:15PM +0200, Eugene Goubine wrote:
> > Hello , dear list users.
> > >From my module I am trying to register for the system suspend using the
> *
> > register_pm_notifier(nb)*
> > which is expanded to *blocking_notifier_chain_register(&pm_chain_head,
> nb).*
> > **
> > I have a linker warning which tells "pm_chain_head" is undefined. I do
> > see  pm_chain_head in my /proc/kallsyms.
> > What do I miss? Thank you.
>
> It's hard to comment on it if you don't attach the source code...
>
> At a guess, you tried using register_pm_notifier, that failed to link,
> so you tried to use the function that it calls, which won't work since
> pm_chain_head is static to the kernel/power/main.c compilation unit.
>
> License your module under the GPL and add MODULE_LICENSE("GPL") and
> you'll be able to use the register_pm_notifier export...
>
> regards, Kyle
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/fedora-kernel-list/attachments/20080219/fda9a529/attachment.htm>
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: proto_module.txt
URL: <http://listman.redhat.com/archives/fedora-kernel-list/attachments/20080219/fda9a529/attachment.txt>


More information about the Fedora-kernel-list mailing list