SEGFAULT with MM HEAD when probing

[Aleksander Morgado]

Hey

On Wed, Apr 21, 2021 at 9:33 PM Bjørn Mork <bjorn at mork.no> wrote:
>
> Aleksander Morgado <aleksander at aleksander.es> writes:
>
> >> > Guess I have to figure out how to build this with a few more symbols and
> >> > running gdb.
> >>
> >> OK, so now I have:
> >>
> >> [6596]: <debug> [1619029470.853036] [ttyUSB0/qcdm] opening serial port...
> >> [6596]: <debug> [1619029470.854109] [ttyUSB0/qcdm] device open count is 1 (open)
> >> [6596]: <debug> [1619029470.854688] [cdc-wdm0/probe] probing QMI...
> >>
> >> Thread 1 "ModemManager" received signal SIGSEGV, Segmentation fault.
> >> 0x77a7310f in install_property_internal () from /usr/lib/libgobject-2.0.so.0
> >> (gdb) bt
> >> #0  0x77a7310f in install_property_internal () from /usr/lib/libgobject-2.0.so.0
> >> #1  0x77a731db in validate_and_install_class_property () from /usr/lib/libgobject-2.0.so.0
> >> Backtrace stopped: frame did not save the PC
> >>
> >
> > Any chance you can try with the same device on a PC under valgrind? It
> > looks like a memory issue.
>
> Nope, sorry.  It's a LGA modem soldered to the MIPS main board.  So
> that's a no-go.  But it is pretty similary to the RM50xQ devices if
> anyone has one of those.  I don't, unfortunately.
>

I have access to one, but on a setup running 1.16.x, cannot upgrade to
git master there. I'll try with some other new QMI device.

> Bu can't I just run valgrind on the MIPS CPU?  Any hints on how to use
> valgrind?  It's one of those tools I've been thing that I should
> explore, but never have..
>

I have no idea if you can run valgrind on that setup, just give it a
try maybe? If we're interested in finding invalid read/writes in
memory (ignoring leaks), the valgrind call would be basically this:
# G_SLICE=always-malloc valgrind --log-file=valgrind.log
/usr/sbin/ModemManager --debug

The valgrind.log file would contain the errors reported.

-- 
Aleksander
https://aleksander.es