/usr/share/glmark2/shaders/loop-step-loop.all is in glmark2-data 2014.03+git20150611.fa71af2d-0ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | for (int i = 0; i < $NLOOPS$; i++)
d = fract(3.0 * d);
|