On Mon, Nov 25, 2013 at 7:30 AM, jb <jb.1234abcd@xxxxxxxxx> wrote: > Rodrigo Rivas <rodrigorivascosta <at> gmail.com> writes: > > > ... > > The problem is in the "signal mask". It looks like some process masks the > > signals in the early boot, and then the signal mask is inherited by all > the > > process in my session. And, as it seems, `gdb` needs a lot of signals to > > work properly, but it assumes that they are not masked at the beginning. > I > > don't know if this should be considered a gdb bug or not, but the real > > problem is elsewhere. > > ... > > So I am now pretty sure that some process in the session is corrupting > the > > signal mask. The only thing left is to know which one... > > Review it: > $ pstree -p > > Your signal blocking could come from: > - GUI Login Manager, DE session, ... > Check for gnome-session PID and for its parent PID: > $ grep SigBlk /proc/$pid/status > - gnome-terminal (I guess) in which you run gdb > Check as above. > > This entry gives you an overview of signal states; > it will help you match processes to e.g. SigBlk pattern: > $ ps axs | grep fffffffe7ffbfeff > > Btw, a similar problem occured there: > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=499569 I think I've finally solved it! The first process in my session that gets the wrong signal mask is cinnamon-session, so that's where I started looking. I managed to trace the bug until the conection to logind via dbus. But the connection is made using glib/gio, so I looked there. Then I traced the glib code until a deep buried call to `pthread_create()`. That is in glibc! So I got the sources and debugged again. There things get complicated... The bug happens somewhere between glib calling pthread_create() and glibc's implementation of that very same function. I got a few stack traces and they all pointed to one suspect... /usr/lib/libnvidia-tls.so.331.20 Alas, the source of that file is not available, so my investigation ends here. I did a rollback to nvidia-325.15-11 and {nvidia-libgl,nvidia-utils,opencl-nvidia}-325.15-1 and all is back to normality 8-). A quick search in the web shows that it has happened before [1] [2] [3] I'm reporting my findings out there. To anybody that is still reading, thank you for you attention. -- Rodrigo. [1] https://devtalk.nvidia.com/default/topic/638521/linux/gnome-terminal-problems-ctrl-c-and-exit/ [2] https://bugzilla.redhat.com/show_bug.cgi?id=1028272 [3] https://bbs.archlinux.org/viewtopic.php?pid=1350302
