Re: PATCH: Handle DF_1_INTERPOSE

["H. J. Lu" <hjl at lucon dot org>]

On Fri, May 30, 2003 at 09:26:15PM -0700, Ulrich Drepper wrote:
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> H. J. Lu wrote:
> 
> > Good. Will it help pthread and glibc if libpthreads.so is marked with
> > DF_1_INTERPOSE?
> 
> Why should it?  It can only hurt.  I find the whole option pointless.
> The programmer has no control over the order in the search scope.  Every
> DSO can be marked this way.  As soon as more than one is marked (or
> LD_PRELOAD is also used) all the effects are negated.

"-z interpose" is supposed to work similar to LD_PRELOAD. The main
difference is it is done automatically. Like any shared libraries,
things can go wrong if it is not used appropriately.

> 
> I haven't looked at the implementation yet since I first would like to
> know what this option should be good for?
> 

We find a need to interpose some functions in libc.so automatically
independent of the link order without using LD_PRELOAD. "-z interpose"
does what we need.


H.J.