Specifically, Gajim's use of python-crypto (or something similar) has been causing the kernel to lock up for me, months ago. 100% repro rate: I would launch Gajim, and kernel would lock up on the relevant core even before Gajim showed the first window.
Trying to pinpoint it using
strace, it was actually an attempt to read
/proc/brcm_monitor0. I have no idea why it would try to read it, but once it did, kernel would lock up on one CPU core (seen by examining
dmesg), and slowly other CPU cores would follow.
Given that I don't actually need the Broadcom wireless card on my desktop machine (at least ever since I wired up my room), I've just blacklisted the
$ cat /etc/modprobe.d/blacklist-IVUCICA.conf blacklist wl