Re: ld and GNU/Linux ld.so disagree on dependent library search order (?)

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

On Mon, Feb 06, 2006 at 12:42:52PM -0500, Jeremy Brown wrote:
> Ian Lance Taylor <ian@airs.com> writes:
> > ld and ld.so should use the same search path for shared libraries.
> > Anything else is a bug.  It sounds like you have found a bug, or else
> > the ld.so behaviour has changed.
> 
> Certainly both seem to be behaving as they are documented to; it's
> just that they are documented as behaving differently.
> 
> At the bottom of this email is a sequence of commands that illustrates
> the problem on my Fedora core 3 x86_64 box.  It relies on the implicit
> dependency of libgnome-2 on libxml2.  It needs to be run as root,
> because it adjusts (and then resets) ld.so.conf.
> 
> Here's the most interesting part of the output.  At this point,
> libxml2 has been copied into /usr/lib/test, and /usr/lib/test is the
> first entry in /etc/ld.so.conf. 
> 
> 1 sh-3.00#  gcc -Xlinker -verbose foo.c -o foo -lgnome-2 2>&1 | grep libxml2
> 2 libxml2.so.2 needed by /usr/lib64/libgnomevfs-2.so.0
> 3 found libxml2.so.2 at /usr/lib64/libxml2.so.2  
> 4 sh-3.00#  ldd foo | grep libxml2
> 5         libxml2.so.2 => /usr/lib/test/libxml2.so.2 (0x00002aaaac16b000)
> 6 sh-3.00#  LD_DEBUG=libs ./foo 2>&1 | grep libxml2
> 7      24661:     find library=libxml2.so.2 [0]; searching
> 8      24661:       trying file=/usr/lib/test/libxml2.so.2
> 9      24661:     calling init: /usr/lib/test/libxml2.so.2
> 10     24661:     calling fini: /usr/lib/test/libxml2.so.2 [0]
> 
> Note that at line 3, the linker reports finding libxml2 at
> /usr/lib64/libxml2, while at line 5, ldd finds it in /usr/lib/test/ As
> another check, lines 8-10 show that ld.so also finds it in
> /usr/lib/test  
> 
> As I said, this is consistent with the way both ld and ld.so are
> documented, but very, very annoying.  My opinion is that ld is doing
> the wrong thing here: it should favor paths in /etc/ld.so.conf ahead
> of hard-coded system paths.
> 
> Should I report this as a bug?
> 
> Thanks for your time,
> Jeremy
> 

Please open a bug report with a testcase. I will look into it.

Thanks.


H.J.