Re: [MODULES] fix weak symbol handling

[Rusty Russell <rusty@rustcorp.com.au>]

In message <20030114171250.C5751@twiddle.net> you write:
> On Tue, Jan 14, 2003 at 07:39:44PM +1100, Rusty Russell wrote:
> > After that's reverted, here's my implementation.  Richard?
> 
> Nope.  Doesn't handle undef weak.  Handling of defined weak
> I'm not sure is necessary at all; I can't think of any good
> use for it in the kernel.

I didn't know about undefined weak symbols.  I was thinking:

int nosupport_function(void)
{
	return -ENOSYS;
}

extern int support_function(void)
	__attribute__((alias("nosupport_function"), weak));

....

int init(void)
{
	/* Or you could simply call it... */
	if (support_function == nosupport_function)
		...


Of course, you can use symbol_get and symbol_put, too, but they don't
work if !CONFIG_MODULES: I chose to implement that case as simply a
reference, so you'll get a link failure: see linux/module.h.

Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.