Fglrx: 3D applications either crash or hang system

Question

I have a new Radeon 270X. RadeonSI doesn't work at all even with Linux 3.14 (corruption/black screen even before X is started) and Catalyst barely works. Catalysts, however, works fine on Ubuntu 14.04, as far as I can tell.
The problem is that the applications either crash a few seconds after they are started (1-20 seconds depending on the application), in which case, I see something like:
[  250.217033] traps: valley_x64[1739] general protection ip:7f16fa40ce67 sp:7fff203f3730 error:0 in libc-2.19.so[7f16fa3d5000+19e000]
or they hang the system. I can still ssh into the machine and I can see xorg taking 100% cpu, but I am unable to kill X or even reboot from there.
I tried Catalyst 13.12 (xorg 1.14), 14.02 (xorg 1.15) and 14.03 (xorg 1.15). The behavior is similar. This is the Ubuntu package that works (seems to be 14.03):
root@sugo:/# apt-cache policy fglrx
fglrx:
Installed: 2:13.350.1-0ubuntu1
Candidate: 2:13.350.1-0ubuntu1
Version table:
*** 2:13.350.1-0ubuntu1 0
500 http://nl.archive.ubuntu.com/ubuntu/ trusty/restricted amd64 Packages
100 /var/lib/dpkg/status
Any idea what could be wrong?
Last edited by cataphract (2014-03-24 02:14:28)

Answer 1

OK, I solved the segfaults. After trying a bunch of stuff, including using Ubuntu's kernel, and noticing that a fresh install of arch in a usb stick didn't have this problem, I removed the mesa package in desperation and with it 4GB of dependents. After installing catalyst-test again, the segfaults were gone.
So now I "only" have unkillable xorg processes hanging the machine. This affects Cities in Motion 2 and Metro: Last Light, but not other the unigine demos and its Oil Rush game and Dota 2. If anyone has any ideas on this, I'd appreciate it.