Re: external gpl kernel module build problem on 2.6.26.8-rt16

[Mark Hounschell <dmarkh@cfl.rr.com>]

Frank Rowand wrote:
> Mark Hounschell wrote:
>> I get the following while trying to build this driver. What does it mean.
>>
>>  Building modules, stage 2.
>>  MODPOST 1 modules
>> WARNING: "__bad_func_type" [/local/work/markh/pci5565-linux/driver/rfm2g.ko]
>> undefined!
>>
>> Then obviously the module doesn't load for the same reason.
>>
>> When I grep the kernel for bad_func_type all I see is
>>
>> include/linux/rt_lock.h:192:extern int __bad_func_type(void);
>> include/linux/pickop.h:8:extern int __bad_func_type(void);
>> include/linux/pickop.h:16:      else __bad_func_type();
>>                 \
>> include/linux/pickop.h:27:      else __ret = __bad_func_type();
>>
>> Any help or hints would be appreciated
>>
>> Thanks in advance
>> Mark
> 
> #define PICK_FUNCTION(type1, type2, func1, func2, arg0, ...)            \
> do {                                                                    \
>         if (PICK_TYPE_EQUAL((arg0), type1))                             \
>                 func1((type1)(arg0), ##__VA_ARGS__);                    \
>         else if (PICK_TYPE_EQUAL((arg0), type2))                        \
>                 func2((type2)(arg0), ##__VA_ARGS__);                    \
>         else __bad_func_type();                                         \
> } while (0)
> 
> And PICK_FUNCTION_RET() uses the same technique.
> 
> Something that invokes PICK_FUNCTION() or PICK_FUNCTION_RET() is passing
> in an arg0 that is not type1 and is not type2.
> 
> One easy way to figure out what is invoking PICK_FUNCTION()/PICK_FUNCTION_RET()
> is to look at the output from the cpp of your driver.  The method I usually
> use is to add the flags "-C -E" to my compile command (and remove "-c").
> Then search the cpp output for __bad_func_type.
> 

Thanks for the pointer. How might one do this using the kernel build system
though? Isn't the compile command used actually the kernels compile command?
Can I assume this would entail modifying the kernels top Makefile in some way?

Thanks again
Mark