From: Bart Trojanowski <bart@jukie.net>
To: Anthony Chee <anthony.chee@polyu.edu.hk>, linux-kernel@vger.kernel.org
Cc: kbuild-devel@vger.kernel.org, kernelnewbies@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: undefined reference
Date: Mon, 25 Mar 2002 16:45:35 -0500 [thread overview]
Message-ID: <20020325164535.A5144@jukie.net> (raw)
In-Reply-To: <004501c1d34f$32bda110$0100a8c0@winxp>
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* Anthony Chee <anthony.chee@polyu.edu.hk> [020324 11:17]:
> I am now developing a module. This module need communicate with the kernel.
> So I exported a function func(), by using EXPORT_SYMBOL(func). In the header
> file, I set "extern int func()".
<snip>
The problem you face is that the kernel needs to know where foo is to
generate a the bytecode that calls it. Here is a better scenario...
You expose an interface in the kernel such as
typedef void (*func_t)(int);
void register_func ( func_t func );
EXPORT_SYMBOL (register_func);
Then in your modules you call 'register_func' and that will pass the
function in question to the kernel. The kernel can then do whatever it
wants to that pointer (like call it).
B.
--
WebSig: http://www.jukie.net/~bart/sig/
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next prev parent reply other threads:[~2002-03-25 21:46 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-03-24 16:16 undefined reference Anthony Chee
2002-03-25 21:45 ` Bart Trojanowski [this message]
2002-03-26 4:17 ` Anthony Chee
2002-03-26 5:49 ` Keith Owens
2002-03-30 14:19 ` Anthony Chee
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