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Date: Tue, 6 May 2003 17:49:53 +0200 (CEST)
From: Harti Brandt <brandt@fokus.fraunhofer.de>
To: "Jacques A. Vidrine" <nectar@FreeBSD.org>
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cc: "Andrey A. Chernov" <ache@nagual.pp.ru>
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cc: freebsd-arch@FreeBSD.org
Subject: Re: `Hiding' libc symbols
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On Tue, 6 May 2003, Jacques A. Vidrine wrote:

JAV>On Tue, May 06, 2003 at 09:56:06AM +0200, Harti Brandt wrote:
JAV>> There is no guarantee that you 'fix' the port by hiding the symbol.  You
JAV>> may as well break it. This depends on the function itself and on the
JAV>> internal relationships in libc. You have to go through each individual
JAV>> port and see what happens anyway.
JAV>
JAV>Please explain.  I _am_ guaranteed that keeping the port from hijacking
JAV>strlcpy calls in libc will not break the port.  How could the port rely
JAV>on the internals of libc?

Well, strlcpy is not a very interesting example because it stand on its
own. More interesting are examples where library functions depend on each
other (malloc/free, fopen and co.) The user calls its own malloc(), the
library tries to free with its own free().

The application could replace *printf() to actually redirect output...

At the end the port might have its own strlcpy to track buffers it has
written to for whatever reason.

harti
-- 
harti brandt,
http://www.fokus.fraunhofer.de/research/cc/cats/employees/hartmut.brandt/private
brandt@fokus.fraunhofer.de, harti@freebsd.org