[maemo-developers] [maemo-developers] Debugging maemo_af_desktop crashes

[From: Johan Bilien]

On Thu, Dec 07, 2006, Marius Gedminas wrote:
> I believe I've mentioned before that my 770 likes to reboot spontaneously.
> /proc/bootreason is sw_rst, /var/lib/dsme/stats/lifeguard_resets usually
> indicates /usr/bin/maemo_af_desktop (46 times already, out of 54
> resets).  I mkdir'ed /media/mmc1/core-dumps and now have a core file
> from the last crash.  Question: what can I do with it?
> 
> gdb on the 770 doesn't appear to be very useful:
> 
> /media/mmc1/core-dumps $ gdb maemo_af_desktop core.959
> ...
> warning: core file may not match specified executable file.
> Core was generated by `/usr/bin/maemo_af_desktop'.
> Program terminated with signal 6, Aborted.
> Reading symbols from /lib/libc.so.6...(no debugging symbols found)...done.
> Loaded symbols for /lib/libc.so.6
> Reading symbols from /lib/ld-linux.so.3...(no debugging symbols found)...done.
> Loaded symbols for /lib/ld-linux.so.3
> #0  0x40047c14 in kill () from /lib/libc.so.6
> (gdb) bt
> #0  0x40047c14 in kill () from /lib/libc.so.6
> #1  0x40047a2c in raise () from /lib/libc.so.6
> #2  0x00008f20 in ?? ()
> 
> 
> I'm still running mistral.  I've two status bar applets installed
> (panelclock 0.5 and load-applet-run 0.4.3-2), but previously I've seen
> these spontaneous reboots with only osso-statusbar-cpu installed instead
> of these two.
> 
> (I also happen to have four other core files from previous crashes:
> browser, maemo-launcher, dsme, osso_hss.)

A few things:

. maemo_af_desktop uses maemo-launcher. This means that the
maemo-launcher process is the one actually running the maemo_af_desktop
code. When a crash happens you should see 2 core files (with consecutive
pids):
  .  a small one from maemo_af_desktop, which is just coming from the
     maemo-invoker process which tells maemo-launcher to load
     maemo_af_desktop.launch
  . a big one (several MB) which is maemo-launcher running
    maemo_af_desktop.launch. That's the interesting one.

so to get something useful you need to run gdb /usr/bin/maemo-launcher
thebigcorefile

. you will need all the debug symbols. Unfortunately it seems the debug
packages (-dbg) are all missing from mistral and scirocco. Ferenc, Tran,
do you know why? Now the only way would be to apt-get source libc6, gtk,
glib, and maemo-af-destkop and rebuild them :(

You can also send me the core file I can take a look.

Regards,
-- 
Johan Bilien
<jobi at via.ecp.fr>