Bug 111009

Created attachment 144650 [details]
The shader containing code that produces an error and the stack trace by catchsegv.

I ran a piglit shader test with the following fragment shader which should render the red solid color image. However, I got an error: Segmentation fault (core dumped). The attachment are the shader and the log obtained when running shader runner with catchsegv tool (by using command “catchsegv ./bin/shader_runner_gles3 shaders/sample.shader_test”).

void main()
{
 for(
     int _injected_loop_counter = 0;
     1 != int((injectionSwitch.y));
     1
 )
  {
   if(gl_FragCoord.y < 0.0)
    {
     return;
    }
  }
 do
  {
   _GLF_color = vec4(1.0, 0.0, 0.0, 1.0);
   if(gl_FragCoord.x < 0.0)
    {
     discard;
    }
  }
 while(0.0 > injectionSwitch.y);
}

[test]
uniform vec2 injectionSwitch 0.0 1.0
draw rect -1 -1 2 2


Steps to reproduce:
-------------------------------------------------------------------------------
1. Obtain and build piglit, the Mesa OpenGL test suite runner: https://gitlab.freedesktop.org/mesa/piglit
2. Download the attached archive.
3. From a terminal, execute the supplied tests with the piglit GLES3 shader runner: 
$ bin/shader_runner_gles3 result.shader_test


Build & PC specs:
-------------------------------------------------------------------------------
CPU: Intel Core i7-2860QM
GPU: Intel Sandybridge Mobile

OS: Ubuntu 18.04.2 LTS
libdrm: git-46cb2aa1ede16380df2d965ca125d855c4278823 (most recent as of this writing)
Mesa: git-d19fe5e67a3945582448748c72b10fd5029d2ed5 (most recent as of this writing)
Linux kernel version: 4.18.0-20-generic

This bug was found with GraphicsFuzz: https://github.com/google/graphicsfuzz