Re: Fast LKM symbol resolution with SysV ELH hash table

[Robert Hancock <hancockrwd@gmail.com>]

On 10/19/2009 09:02 AM, Carmelo Amoroso wrote:
> 2009/10/19 Greg KH<greg@kroah.com>:
>> On Mon, Oct 19, 2009 at 01:45:20PM +0200, Carmelo Amoroso wrote:
>>> Just a few other notes. The current implementation I did based on SysV
>>> has a drawback that is not backward compatible, so you cannot use old
>>> modules with a kernel with the option enabled due to changes on struct
>>> kernel_symbol.
>>
>> Why would this be a problem?  Whenever making a kernel config change,
>> you should be able to rebuild everything, as lots of other configuration
>> options are that way.
>>
>
> This is not always true... there could be cases in which you cannot
> recompile old modules
> (e.g vendors that provide non GPL modules)

Even non-GPL modules can normally be rebuilt as far as the module format 
is concerned, there's usually an object file blob that gets compiled 
into a module on install or something, like the Nvidia graphics driver. 
If anyone's providing binary-only fully built modules (which would be 
inherently tied to one exact kernel version and one configuration) they 
really need to have their head examined..