Re: Bug#608347: libtbb2-dbg: Segfault at _dl_relocate_object() dl-reloc.c:242 0x00007ffff7de9b03

[Jorge Moraleda <jorge.moraleda@gmail.com>]

Dear Neil and Roberto, 

Thank you for looking so quickly into this. Here are instructions on how to reproduce the bug:

1) For source code we will use one of the examples that come with the library. To obtain the example install package tbb-examples.

2) Following the instructions in /usr/share/doc/tbb-examples/README.debian, we will make a copy of the examples source to a directory where we have write permissions:

cd ~
cp -r /usr/share/doc/tbb-examples/ .
cd tbb-examples
find . -name '*.gz'| xargs gunzip
cd examples

3) The README.debian file now calls to execute "make" to build all examples. Unfortunately the Makefiles shipped with the examples have not been debianized, so they will fail because the directory structure in debian is not the same one that you get when you install directly from http://www.threadingbuildingblocks.org/file.php?fid=77, which is what the current Makefiles expect (this is a separate bug that should be filed against package tbb-examples), so instead, we will fix the Makefile for one of the examples:

cd parallel_for/tachyon
perl -p -i -e "s/-ltbb_debug/\/usr\/lib\/debug\/usr\/lib\/libtbb.so.2/g" Makefile

4) We will make and try the release version:

make release
./tachyon.tbb

We get some Usage output

5) Now the debug version:

make clean
make debug
./tachyon.tbb

We get a Segmentation fault

My guess is that the libraries in debug mode need to be compiled with some switch in g++ but unfortunately I don't know what it is. 

Thank you. Regards,

Jorge

On Thu, Dec 30, 2010 at 2:33 AM, Neil Williams <codehelp@debian.org> wrote:

On Wed, 29 Dec 2010 22:06:52 -0500
Roberto C. Sánchez <roberto@connexer.com> wrote:

> I am curious as to whether the release team thinks that #608347
> (quoted below) is really RC.  Do I need to target the fix for this to
> go into Squeeze?

I've tried a simple test program to replicate the results but I don't
know enough about the library to get it to compile.

Is there a snippet of C code which can be compiled with a simple:

$ gcc -o test -ltbb test.c

?

(Preferably a sample which just #include's the appropriate headers and
doesn't have to initialise too much other stuff.)

It doesn't seem fair to seek judgement on the importance of the bug
report without being able to reproduce the problem or find out whether
the problem actually exists on other systems than that of the submitter.

> > When linking against the tbb debug libraries from the package, a
> > segmentation fault occurs at initialization time:

It would be very useful to have a test case piece of code from the
original use case too.

--


Neil Williams
=============
http://www.linux.codehelp.co.uk/