topic I came here to report in Graphics

GLSL linker crash with sampler2DShadow array

Nicolas_L_1 — Thu, 24 Sep 2015 20:10:06 GMT

Hi,

System Setup Information:

-----------------------------------------

System Used: Microsoft Surface Pro 3
CPU SKU: i5
GPU SKU: HD4400
Processor Line: ?
System BIOS Version: ?
CMOS settings: ?
Graphics Driver Version: 10.18.14.4264
GOP/VBIOS Version: ?
Operating System: Windows
OS Version: 8.1
API: OpenGL
Occurs on non-Intel GPUs?: No

Steps to Reproduce:
-------------------------------
1. Compile & link the following vertex & fragment shaders (also can be found here ; https://gist.github.com/nicomgd/08edf6a7741500997414)

shader.frag
#version 150

// UNCOMMENT the following line to crash the linker
// Crash happens on driver 10.18.14.4264 on Windows 8.1 x64, on Intel HD 4400
#define CRASH_DRIVER_PLEASE

in vec4 var_shadowTexCoords;
uniform sampler2DShadow py_shadowMaps[ 1 ];

out vec4 fragColor;

#ifdef CRASH_DRIVER_PLEASE

float _eval_shadow( sampler2DShadow shadowMap, vec4 shadowTexCoord )
{
  return textureProj( shadowMap, shadowTexCoord );
}

#else

#define _eval_shadow(a, b) textureProj(a, b)

#endif

void main(void)
{
    float shadow_factor = _eval_shadow( py_shadowMaps[0], var_shadowTexCoords );
    fragColor = vec4(shadow_factor);
}


shader.vert
#version 150

out vec4 var_shadowTexCoords;

void init_shadows_es( vec4 someVertex )
{
  var_shadowTexCoords = someVertex;
}

in vec4 mg_vertex;

void main(void)
{
  init_shadows_es(mg_vertex);
  gl_Position = mg_vertex;
}

Expected Results:

-------------------------------

Shaders compile and link.

Actual Results:
-------------------------------

Shaders compile, and the call to glLinkProgram crashes the application.

Additional Information:
-------------------------------

The code posted above is a stripped down version of a bigger shader.

My understanding is that passing an element of a sampler2DShadow array as an argument to a function causes the crash. If the uniform is changed to become a simple sampler2DShadow value, the crash goes away, idem if the functions are replaced by macros.

FWIW the problem does not occur on the latest avail. driver for HD4000.

Hi,

Michael_C_Intel2 — Fri, 25 Sep 2015 15:12:48 GMT

Hi,

Thanks for filling out the information. I have will get an internal ticket going and talk to the driver team about it.

-Michael

I came here to report

invisible-cow — Tue, 16 Aug 2016 05:43:37 GMT

I came here to report something very similar. Working on a Blender bug report https://developer.blender.org/T49089. Original reporter is using HD 4600. Below is my system info, after reproducing the crash.

Problem seen when viewing a particular test file. Shaders involved are rather big... generated code from Blender's nodal material system. I'll look for any sampler2DShadow arrays & report back.

System Setup Information:
-----------------------------------------

System Used: Asus Z87-Plus
CPU SKU: i5-4670K
GPU SKU: HD 4600
System BIOS Version: 2170 PC 14.34 03/07/2013
Graphics Driver Version: 10.18.15.4279 WHQL / Win 10 64
Operating System: Windows
OS Version: 10
API: OpenGL
Occurs on non-Intel GPUs?: no

Expected Results:

-------------------------------

glLinkProgram should 1) succeed or 2) fail & report any problems if given bad input.

Actual Results:
-------------------------------

Crash inside glLinkProgram. The vertex & fragment shaders compiled successfully with nothing in their info logs.

Additional Information:

-------------------------------

Tested with a debug context, debug logging enabled. No errors were reported prior to crash.

Shaders are GLSL #version 150 compatibility. Context is GL 4.3 compatibility profile.

Test file exposes a totally different issue on AMD hardware, nothing to do with shader compilation or linking.