Re: [uml-user] to_virt unresolved symbol while insmod a module.

[Blaisorblade <bla...@ya...>]

On Tuesday 19 April 2005 09:55, Suresh wrote:
> Hi
>
> I am a  newbie to the uml and this my first mail.
> I was trying to bring up uml. I compiled a module and tried to load the
> module into the kernel.
> I get an unresolved symbol for to_virt.

> The kernel functions which I used 
> in the module are
> kmalloc,
> copy_to_user
> copy_from_user
> and free.
to_virt is used in the definition of __va(), IIRC.


> I am not sure why this symbol is not resolved. to_phys is resolved. Both
> are defined in a
> arch/um/kernel/physmem.c file.
But it means that it isn't exported with EXPORT_SYMBOL. Modules can't load all 
kernel symbols, only some ones, which are explicitly exported. Search any 
linux FAQ (this is not UML specific, except the symbol name itself).
> Kindly tell me how to resolve this issue.
Add

EXPORT_SYMBOL(to_virt);

to arch/um/kernel/ksyms.c (any file listed in export-objs in his Makefile 
would be good, in 2.4; any file at all would be good in 2.6).

> The kernel version is 2.4.20 vanilla patched with uml-patch-2.4.20-8.
That version is *very* old, in newer versions it should be fixed, however 
fixing it yourself will be a good exercise.
> regards
> Suresh


-- 
Paolo Giarrusso, aka Blaisorblade
Linux registered user n. 292729
http://www.user-mode-linux.org/~blaisorblade