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Re: Kernel Symbol Clarification



--- At Wed, 18 Jul 2007 22:59:55 -0700, Michael Smith wrote:

>
>On Jul 18, 2007, at 12:03 PM, email@hidden wrote:
>
>> Garth Cummings writes:
>>> The kernel is one big monolithic namespace. All symbols in KEXTs must
>>> be unique across the system as they are linked into that one
>>> namespace. If a KEXT defines a symbol that already exists, the KEXT
>>> will not load.
>>
>> Are you really sure about this?  I thought the relocations were done
>> by kextload in userspace, and the only namespaces that are shared
>> are those of your kext and what it depends on.
>
>Drew, you are correct for more recent MacOS systems.
>
>Garth's description refers to a previous implementation.
>
>An alternative for symbols that are exported between objects in a  
>kext, but which should not be visible outside it, is 'private extern'.

Can you give an example of where private extern would help? I'm not
seeing why this matters? If as Drew says, all linking is done except for
external dependencies before being put into the kernel. 

I would expect that all symbols that could be located within the kext
would be satisfied first and then look for the rest of the symbols
outside the kext. 

Am I not thinking about this correctly? 

 ...Duane

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 >Re: Kernel Symbol Clarification (From: Michael Smith <email@hidden>)



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