Re: Modem Manager stuck in a loop, ppp can't connect.

["A. F. Cano" <afc shibaya lonestar org>]

On Wed, May 10, 2017 at 02:25:51PM -0500, Dan Williams wrote:
> ...

Thanks for the detailed explanations.

> ...
> > May  9 21:02:06 fbx NetworkManager[379]: g_signal_emit_valist:
> > assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
> > May  9 21:02:07 fbx NetworkManager[379]: instance with invalid (NULL)
> > class pointer
>
> This would be a bug in NetworkManager.  Any chance that, when this
> happens, you could 'gdb attach <pid of NetworkManager>', then 'break
> g_log', then 'continue'.  Then next time it breaks out to the '(gdb)'
> prompt, run "t a a bt" to get a backtrace.  That will likely tell us

Thank you very much for the detailed instructions.  It's been many years
since I've used gdb...

> where the issue is.

Ok, the backtrace is below.  Not sure how much help it's going to be
since the executables have not been compiled with debugging symbols.
They're the stock Debian 9.0 binaries on a headless system running on a
4GB SD card.  Still, if there's something else that would help and that
would fit in this minimal system let me know and I'll try to install
it and run it.

Augustine


$ gdb attach 379
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attach: No such file or directory.
Attaching to process 379
[New LWP 447]
[New LWP 449]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007f6c7227f4ed in poll () at ../sysdeps/unix/syscall-template.S:84
84      ../sysdeps/unix/syscall-template.S: No such file or directory.
(gdb) break g_log
Breakpoint 1 at 0x7f6c729b0740
(gdb) continue
Continuing.

Thread 1 "NetworkManager" hit Breakpoint 1, 0x00007f6c729b0740 in g_log ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
(gdb) t a a bt

Thread 3 (Thread 0x7f6c6acf1700 (LWP 449)):
#0  0x00007f6c7227f4ed in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f6c729a99f6 in ?? ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f6c729a9d82 in g_main_loop_run ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f6c72f91656 in ?? ()
   from target:/usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007f6c729d13d5 in ?? ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f6c72545494 in start_thread (arg=0x7f6c6acf1700)
    at pthread_create.c:333
#6  0x00007f6c7228893f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 2 (Thread 0x7f6c6bcf3700 (LWP 447)):
#0  0x00007f6c7227f4ed in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f6c729a99f6 in ?? ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f6c729a9b0c in g_main_context_iteration ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f6c729a9b51 in ?? ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f6c729d13d5 in ?? ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f6c72545494 in start_thread (arg=0x7f6c6bcf3700)
    at pthread_create.c:333
#6  0x00007f6c7228893f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 1 (Thread 0x7f6c74dd9e40 (LWP 379)):
#0  0x00007f6c729b0740 in g_log ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f6c72ca7e8a in g_type_check_instance ()
   from target:/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#2  0x00007f6c72c9cdde in g_signal_emit_valist ()
   from target:/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#3  0x00007f6c72c9dfbf in g_signal_emit ()
   from target:/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#4  0x00007f6c6f4ad038 in ffi_call_unix64 ()
   from target:/usr/lib/x86_64-linux-gnu/libffi.so.6
#5  0x00007f6c6f4aca9a in ffi_call ()
   from target:/usr/lib/x86_64-linux-gnu/libffi.so.6
#6  0x00007f6c72c83c8a in g_cclosure_marshal_generic_va ()
   from target:/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#7  0x00007f6c72c831a4 in ?? ()
   from target:/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#8  0x00007f6c72c9d8cd in g_signal_emit_valist ()
   from target:/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#9  0x00007f6c72c9dfbf in g_signal_emit ()
   from target:/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#10 0x00007f6c6832f1dd in ?? ()
   from target:/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-ppp-plugin.so
#11 0x00007f6c729aa123 in ?? ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#12 0x00007f6c729a96aa in g_main_context_dispatch ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#13 0x00007f6c729a9a60 in ?? ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#14 0x00007f6c729a9d82 in g_main_loop_run ()
   from target:/lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x000055ab58a6a805 in ?? ()
#16 0x00007f6c721c02b1 in __libc_start_main (main=0x55ab58a6a020, argc=2, 
    argv=0x7fff0f60a198, init=<optimized out>, fini=<optimized out>, 
    rtld_fini=<optimized out>, stack_end=0x7fff0f60a188)
    at ../csu/libc-start.c:291
#17 0x000055ab58a6aeda in ?? ()
(gdb)