Re: visibility of symbols defined in a kld module ?

I have the following problem while building a compat layer for compiling
linux drivers on FreeBSD:
a piece of code (let's restrict to a kld if it makes things simpler)
needs to register some information to the system calling a function:

usb_register(&some_data)

where some_data is a structure containing various info (callbacks etc)
for the code.
The problem is, i need to hook the argument of usb_register() to the kld.

If i write

/* in linux_module_header.h */
extern void *my_module_info;

#define usb_register(p) my_module_info = p

/* in linux_driver_stub.c, linked together with the rest of the code */

#include "linux_module_header.h"
void *my_module_info;

I get what i want, but then my_module_info is present in all modules
compiled with the same trick, so what happens when the modules are
kldloaded ? Does this symbol conflict (i.e. is this equivalent to RTLD_GLOBAL)
or each one sees its own symbols (i.e. like RTLD_LOCAL) ?

And besides, this would almost surely fail if i compile these things
not as modules but as part of the kernel.

The other trick i can think of is using some preprocessor-magic to
create unique names for the symbol, e.g. compile each kld with
-DDRIVER_NAME=pwc, -DDRIVER_NAME=gspca, -DDRIVER_NAME=dvb and then have

/* in linux_module_header.h */
#define MODINFO_NAME module_ ## DRIVER_NAME ## _info

extern void *MODINFO_NAME;

#define usb_register(p) MODINFO_NAME = p

/* in linux_driver_stub.c, linked together with the rest of the code */

#include "linux_module_header.h"
void *MODINFO_NAME;

This way each module has a different symbol and there are no conflict.
Other ideas ?

/* in linux_module_header.h */

#define LINUX_MODULE(name) \
static __inline usb_register(p)\
{\
extern void *module_##name##_info;\
module_##name##_info = p;\
}

#define LINUX_MODULE_DCL(name)\
LINUX_MODULE(name)\
void *module_##name##_info

/* in linux_driver_stub.c */
#include "linux_module_header.h"

LINUX_MODULE_DCL(pwc);

/* and in the rest of the code */
#include "linux_module_header.h"

LINUX_MODULE(pwc);

cheers,
danny

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