Date: Tue, 6 May 2003 11:45:41 +0300 (IDT)
From: Yoav Weiss <ml-lkml@unpatched.org>
To: D.A.Fedorov@inp.nsk.su, <terje.eggestad@scali.com>,
       <76306.1226@compuserve.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: The disappearing sys_call_table export.
Message-ID: <Pine.LNX.4.44.0305061133290.2977-100000@marcellos.corky.net>
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> But how? When some global will not be exported, it would not be listed
> in /proc/ksyms.

So what ?
You just find the right address (in this case by getting the addresses of
exported syscalls and finding a list in memory, containing them in the
right order), and cast it to be the syscall table.  If you want it to work
with a binary-only driver, you can even insmod a small module that does
that and adds the result to the symbol table for other modules to use.

We've been doing that for years on closed-source systems like AIX.  The
above is just one way to locate a struct in memory.  A faster way is to
find some exported structs which are known to point to the unexported
symbol from some offset, extract the symbol's address, and "re-export" it.

In fact, in linux which is opensource, you can probably write a script
that extracts any unexported symbol from the source code, find a path to
it from some exported symbol, and automagically create a module that
re-exports this symbol for your legacy driver to use.

If you write the script, don't forget to GPL it :)

	Yoav Weiss

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