crash on editing array in shader because Nvidia OpenGL compiler crash

[danilw]

Godot version:
3.2.2 stable

OS/device including version:
Linux Godot editor
Nvidia driver 440.82

Issue description:

handle_crash: Program crashed with signal 11
Dumping the backtrace. Please include this when reporting the bug on https://github.com/godotengine/godot/issues
[1] /lib64/libc.so.6(+0x3c530) [0x7f5c7cf22530] (??:0)
[2] /usr/lib64/libnvidia-glcore.so.440.82(+0x49d430) [0x7f5c76110430] (??:0)
[3] /usr/lib64/libnvidia-glcore.so.440.82(+0x2b1839) [0x7f5c75f24839] (??:0)
[4] /usr/lib64/libnvidia-glcore.so.440.82(+0x2b5b1c) [0x7f5c75f28b1c] (??:0)
[5] /usr/lib64/libnvidia-glcore.so.440.82(+0x2b1c16) [0x7f5c75f24c16] (??:0)
[6] /usr/lib64/libnvidia-glcore.so.440.82(+0x2b1b1d) [0x7f5c75f24b1d] (??:0)
[7] /usr/lib64/libnvidia-glcore.so.440.82(+0x2b8454) [0x7f5c75f2b454] (??:0)
[8] /usr/lib64/libnvidia-glcore.so.440.82(+0x2b8e44) [0x7f5c75f2be44] (??:0)
[9] /usr/lib64/libnvidia-glcore.so.440.82(+0x2b91c4) [0x7f5c75f2c1c4] (??:0)
[10] /usr/lib64/libnvidia-glcore.so.440.82(+0x29008c) [0x7f5c75f0308c] (??:0)
[11] /usr/lib64/libnvidia-glcore.so.440.82(+0x2957a4) [0x7f5c75f087a4] (??:0)
[12] /usr/lib64/libnvidia-glcore.so.440.82(+0x296010) [0x7f5c75f09010] (??:0)
[13] /usr/lib64/libnvidia-glcore.so.440.82(+0xc2f8f0) [0x7f5c768a28f0] (??:0)
[14] /usr/lib64/libnvidia-glcore.so.440.82(+0xc37885) [0x7f5c768aa885] (??:0)
[15] /usr/lib64/libnvidia-glcore.so.440.82(+0xc45ea3) [0x7f5c768b8ea3] (??:0)
[16] /usr/lib64/libnvidia-glcore.so.440.82(+0xc057f3) [0x7f5c768787f3] (??:0)
[17] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x2363d25] (<artificial>:?)
[18] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x236446f] (??:?)
[19] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x9993a4] (??:?)
[20] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x238e5cd] (<artificial>:?)
[21] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0xffbfe3] (??:?)
[22] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x9971e8] (??:?)
[23] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x1037fda] (<artificial>:?)
[24] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x103a01a] (<artificial>:?)
[25] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x103a87f] (<artificial>:?)
[26] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x294a8e2] (??:?)
[27] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x8582dd] (??:?)
[28] /lib64/libc.so.6(__libc_start_main+0xea) [0x7f5c7cf0ccca] (??:0)
[29] /home/danil/bin/godot_3.2.2/Godot_v3.2.2-stable_x11.64() [0x86695e] (??:?)
-- END OF BACKTRACE --

Steps to reproduce:
shader code:

shader_type spatial;
render_mode blend_mix,depth_draw_alpha_prepass,cull_back,unshaded;
 

//bug
void crash_bug(out vec4 col)
{
    vec4 v[2];
    v[0] = vec4(1.0 );
    v[1] = vec4(1.0 );
    mat4 m = mat4(1.);
    float t = 0.0;
    for(int i = 0; i < 8; ++i)
    {
        vec4 s = m * v[i];
        if((s.w<=-1.001)){
            vec2 sp = s.xy / s.w;

            //BUG
            t = max(t,sp.x); // uncomment this
        }
    }
    col = vec4(t);
 
}

void fragment() {
	vec4 col=vec4(0.);
	
	//BUG
	//crash_bug(col); //uncomment this
	
    ALBEDO = col.rgb;
}

uncomment //crash_bug(col); in Godot editor

I was editing shader array and got a full Godot editor crash.

Nvidia bugreport

Minimal reproduction project:
BUG_crash_shader_array.zip

[clayjohn]

Thanks for the heads up! Hopefully NVidia fixes their drivers quickly.

[danilw]

Thanks for the heads up! Hopefully NVidia fixes their drivers quickly.

I think creating some like "dummy-compiler" as an external app (exe/bin file) outside editor and launch shader compilation on that "dummy.exe"(that just call OpenGL shader creation) and return status if no status returned then this shader crash and Godot Editor will show warning "this shader can not be compiled even if its valid"

because these crashes on shader compilation/loading precompiled SPIR-V happened even in Vulkan, glslangValidator application is not safe to "trust it" and SPIR-V output by glslang also can be broken because bugs in glslang, and loading SPIR-V may triger driver bugs that also will crash Godot Editor...

as examples:
glslangValidator bug KhronosGroup/glslang#2368
AMD driver bug on loading SPIR-V file that crash even AMD shader analyzer software https://community.amd.com/thread/248773

I mean "full editor crash" on shader compilation can be avoided

[danilw]

same as #43055

I think it can be closed because the latest Nvidia driver brings even more "GLSL" bugs than this...