crashing apps

[edscott wilson garcia]

Brian, here's my hypothesis:

The traceback indicates that gedit is splitting into threads on startup
to get all the components running. Let's suppose you have an invalid
memory reference in xfdesktop, but that it does not crash xfdesktop
(this kind of error gives unpredictable results). When g_spawn forks(),
a new copy of xfdesktop is created in memory, but the operating system
optimises things by using a single copy of the read only memory. At this
point you manage to fool the os because of the invalid memory address.
Then the forked process memory gets replaced by gedit, which in turn
splits into threads and shares this memory with all threads. Since
something is screwy with the memory, results may be unpredictable and
vary from one os to another.

Anyways, that would be my first guess and by no means do I claim that it
must be true, just maybe possible. Try catching incorrect memory
references with electric fence for example.  

regards,

Edscott 

El jue, 04-03-2004 a las 22:48, Brian J. Tarricone escribió:
> ok, so i've actually heard this from someone else, so it isn't just me 
> being screwy.  for certain apps (verified for gnome-terminal and gedit 
> so far), when they're launched from the xfdesktop menu, the apps 
> themselves crash shortly after they're spawned.  i converted xfdesktop 
> to use xfce_exec() and it still happens.  the crash occurs regardless of 
> whether or not the app is from the autogenerated menu or from menu.xml.  
> however, with a short 5 line app that just calls xfce_exec() on gedit, 
> everything's fine.
> 
> of course, since they're gnome2 apps, bug-buddy pops up, but for some 
> reason freezes.  i can attach with gdb, but the stack trace doesn't 
> appear useful[1].
> 
> anyone have any thoughts?  i'm having a bit of trouble chasing this 
> down, and i'm not sure where to look.  i could understand if it were 
> crashing xfdesktop, but the fact that the app itself that gets launched 
> is crashing really bothers me.
> 
> ok, this is weirder.  i just messed around with trying to have it fork() 
> before calling xfce_exec() (which didn't work, since the spawned process 
> quits before g_spawn_asnyc() finishes).  so i put it back to just 
> calling xfce_exec(), and now gedit and gnome-terminal don't even start.  
> nothing happens.  it's definitely trying to run something (there's a 
> printf right before the call), but xfce_exec() returns true and nothing 
> happens.  bizarre.
> 
>     -brian
> 
> [1] stack trace for crashed gedit:
> 
> #0  0x404d27e8 in waitpid () from /lib/libpthread.so.0
> #1  0x47b39bf0 in ?? () from /usr/lib/libgnomeui-2.so.0
> #2  0x47afc6b8 in libgnomeui_module_info_get () from 
> /usr/lib/libgnomeui-2.so.0
> #3  0x404d14d3 in __pthread_clock_settime () from /lib/libpthread.so.0
> #4  <signal handler called>
> #5  0x00000001 in ?? ()
> #6  0x40302074 in _gnome_vfs_process_signal () from 
> /usr/lib/libgnomevfs-2.so.0
> #7  0x404d14d3 in __pthread_clock_settime () from /lib/libpthread.so.0
> #8  <signal handler called>
> #9  0x40568694 in sigprocmask () from /lib/libc.so.6
> #10 0x40337794 in bonobo_activation_server_by_forking ()
>    from /usr/lib/libbonobo-activation.so.4
> #11 0x40336640 in local_activator () from /usr/lib/libbonobo-activation.so.4
> #12 0x40335d3b in bonobo_activation_internal_service_get_extended ()
>    from /usr/lib/libbonobo-activation.so.4
> #13 0x40335e40 in bonobo_activation_service_get ()
>    from /usr/lib/libbonobo-activation.so.4
> #14 0x4033818c in bonobo_activation_activation_context_get ()
>    from /usr/lib/libbonobo-activation.so.4
> #15 0x4033cbb0 in ?? () from /usr/lib/libbonobo-activation.so.4
> #16 0x00000096 in ?? ()
> #17 0x4032d59f in ?? () from /usr/lib/libbonobo-activation.so.4
> #18 0x40339480 in ORBit_zero_int () from /usr/lib/libbonobo-activation.so.4
> #19 0x4033a5c7 in ORBit_zero_int () from /usr/lib/libbonobo-activation.so.4
> 
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