Kernel: 4.5.0-0.rc4.git2.2.fc24.x86_64
MESA: git master, Feb 19-20th builds
LLVM: trunk 3.9, Feb 19-20th builds
DDX: 

For some reason, X crashes with radeonsi triggering VM fault, when in GNOME or
KDE environments:


If you open up a shell console (gnome-terminal, konsole etc), run mock as
non-root, as soon as an attempt to prompt for root happens (with gtksu) it
locks up system.

[   38.111551] radeon 0000:01:00.0: GPU fault detected: 146 0x0008480c
[   38.111861] radeon 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_ADDR  
0x00000000
[   38.112219] radeon 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_STATUS
0x0804800C
[   38.112576] VM fault (0x0c, vmid 4) at page 0, read from 'TC2' (0x54433200)
(72)
[   38.112931] radeon 0000:01:00.0: GPU fault detected: 146 0x0008440c
[   38.113229] radeon 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_ADDR  
0x08000000
[   38.113587] radeon 0000:01:00.0:   VM_CONTEXT1_PROTECTION_FAULT_STATUS
0x08044001
[   38.113945] VM fault (0x01, vmid 4) at page 134217728, read from 'TC3'
(0x54433300) (68)

I've attached a VM fault debug of crash