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From: "alexander.long91 at gmail dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug dynamic-link/12939] resolving shared library symbols returns wrong file
Date: Wed, 02 Jul 2014 15:39:00 -0000	[thread overview]
Message-ID: <bug-12939-131-l3ddoR6kLY@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-12939-131@http.sourceware.org/bugzilla/>

https://sourceware.org/bugzilla/show_bug.cgi?id=12939

--- Comment #2 from Alex Long <alexander.long91 at gmail dot com> ---
As suggested in the dladdr() man-page, compiling your code to be position
independent, using -fPIC for example, may cause dladdr to return the path to
the shared library the symbol comes from rather than return the path to the
executable. 

However, one issue with this that I've noticed is that when building on or
cross-compiling for armv7l, dladdr will always return the path to the
executable for exported symbols that also happen to be called within the
program.

When compiled with 
/usr/bin/g++-4.7 main.cpp -o main-ARM -Wall -Wextra -ldl -fPIC

the attached example program prints
"printf comes from /lib/x86_64-linux-gnu/libc.so.6" on x86_64 machines
and
"printf comes from ./main" on armv7l

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  parent reply	other threads:[~2014-07-02 15:39 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-27 16:52 [Bug libc/12939] New: " andi-bz at firstfloor dot org
2012-02-21  2:15 ` [Bug ld.so|libdl/12939] " jsm28 at gcc dot gnu.org
2012-12-19 10:47 ` [Bug dynamic-link/12939] " schwab@linux-m68k.org
2014-06-27 13:03 ` fweimer at redhat dot com
2014-07-02 15:38 ` alexander.long91 at gmail dot com
2014-07-02 15:39 ` alexander.long91 at gmail dot com [this message]
2015-01-12 20:27 ` p.kopyl at samsung dot com

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