Re: [module-init-tools] fix weak symbol handling

From: Richard Henderson (
Date: Thu Jan 16 2003 - 21:09:13 EST

On Fri, Jan 17, 2003 at 12:57:03PM +1100, Rusty Russell wrote:
> > No. The semantics I need is if A references a weak symbol S
> > and *no one* implements it, then S resolves to NULL.
> Sorry, I was unclear. I want to know the dependency semantics:
> If B exports S, should depmod believe A needs B, or not? Your patch
> leaves that semantic (all it does is suppress the errors).

Well, that depends on whether A defines S or not. If A does
define S, then I don't care. I'd say "no", A does not depend
on B. If A does not define S, then most definitely "yes", as
with any other definition.

> I'm not sure what semantics are "right", since I don't know what
> you're trying to do, or what is wrong with get_symbol().

I just told you. Quoted again above. Perhaps the following
dummy module will make things even clearer.

#include <linux/module.h>
#include <linux/init.h>

extern int not_defined __attribute__((weak));

static int init(void) { return &not_defined ? -EINVAL : 0; }

static void fini(void) { }

module_init(init); module_exit(fini); ---

You should be able to load this module.

r~ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to More majordomo info at Please read the FAQ at

This archive was generated by hypermail 2b29 : Thu Jan 23 2003 - 22:00:15 EST