how to add a new glibc symbol ?

[Roger Oberholtzer]

On Wed, 3 Dec 2003 09:23:42 -0500 (EST)
Net Llama! <netllama at linux-sxs.org> wrote:

> On Wed, 3 Dec 2003, Roger Oberholtzer wrote:
> > The Linux program loader will load a DSO (libxx.so) specified in an
> > environment variable when an application starts. This would allow you to
> > make a dummy library to provide the missing label. I always thought this
> > was both a neat and a dangerous feature. I believe it it the very first
> > thing loaded, so it should be available to libc.
> >
> > Let me know if you are interested and I will relocate the name of the
> > environment variable. It was something like LD_PRELOAD=libxyx.so.
> 
> Yes, I'm very interested in this.  I think i ran across an LD_PRELOAD
> variable, but didn't quite understand the gist of it.  One problem though,
> is that I have ctype_b.c, so how would I turn that into a shared library
> (so) for use with the LD_PRELOAD var?

I posted a link with examples earlier today. They make it more complicated
bu intercepting the time() function. You need not be so fancy to just make a
function that satisfies the loader. It included the command lines to compile
and all. Did you see that link?

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