Re: OProfile cannot be loaded as module...

[David Daney <ddaney@avtrex.com>]

Ralf Baechle wrote:
> On Mon, Oct 17, 2005 at 01:14:01PM -0700, David Daney wrote:

>>Fine, but what exactly are the semantics of __attribute__((weak)) in 
>>modules?  It gets resolved when linking with other objects that make up 
>>the module.  But what if the weak symbol can be resolved at module load 
>>time against symbols in either the kernel proper or other modules?
> 
> 
> Yes.
> 
> 
>>What happens if the weak symbol can be resolved by a symbol in a module
>>that is loaded after the one with the weak symbol?  Does it get fixed up
>>when the new module is loaded?
> 
> 
> No, it won't - and I don't think that would be a good idea.  The potencial
> for bugs is just too large.
> 

Given your 'yes' and 'no' answers, the behavior of a module could depend 
on the order in which the modules are loaded, as they can be linked 
differently depending on which modules are already present.

That doesn't seem like a good way of doing things.

If if were up to me (and I know that it is not), I would disallow 
linking of weak symbols at module load time altogether.

David Daney.