Re: dlclose() causing segmentation fault on exit from main()

From: Alexander Popov (s_popovNOSPAM_at_prosyst.bg)
Date: 09/01/04

  • Next message: moma: "Re: QT NEWBIE - USER INPUT HELP" 
    Date: Wed, 1 Sep 2004 12:50:42 +0000

    On 31 Aug 2004 07:13:25 -0700 news@exillis.com (Exillis) wrote:

    Try running this trough valgrind with a libc with debug...
    valgrind (memcheck) will show you what/where exactly is the problem.
    It's a good idea to use a deeper stack trace

    > Hi,
    >
    > I'm running into a problem on Linux while dynamically loading and
    > unloading DSOs. The problem is, if I build with --fuse-cxa-atexit I
    > get a segmentation fault on exit from main() after I've done a
    > dlclose() on a DSO and then exit from main(). Commenting out dlclose()
    > or compiling with --fno-use-cxa-atexit avoids the segmentation fault.
    > My compiler is gcc 3.3 (distro is SuSE 9.0).
    >
    > The seg fault occurs after main() so I cannot set a breakpoint. It
    > seems what's happening is that the DSO has registered destructor calls
    > with atexit() and when main() invokes the destructors (via atexit or
    > _cxa_atexit()) it crashes because the DSO has previously been
    > unloaded.
    >
    > From what I can gather, if I avoid all function-scoped static objects
    > (and static objects declared in anonymous namespaces) the crash won't
    > occur. I tried that. I removed all global static objects and
    > function-scoped static objects and the seg fault still occurs. At this
    > point I don't know where to look to debug this further.
    >
    > I don't want to rely on building with --fno-use-cxa-atexit. I'd like
    > to fix my code and not just cover up the problem with a compiler
    > switch.
    >
    > Has anyone come up with a way to solve this? How can I track done
    > which destructor is still being registered for invoking at exit from
    > main()? I'm hoping to find a global or static object that I missed
    > somewhere (this is a large code base and I may have missed something).
    >
    > Thanks for any help with this!
    >
    > Michael 

    -- 
Alexander Popov                    ProSyst Bulgaria Inc.
Tech Leader                        48 Vladajska Str.
RTOS and JVM Dept.  	           Sofia 1606, Bulgaria
Phone:  +359 2 952 3581/204        http://www.prosyst.com
Mobile: +359 887 663 193           OSGi Technology Leaders
----------------------------------------------------------
  • Next message: moma: "Re: QT NEWBIE - USER INPUT HELP"

    Relevant Pages