Created attachment 121069 [details] fragment shader to test segfault In GLSL, one can specify the location of a subroutine uniform by using something like: #extension GL_ARB_shader_subroutine : require #extension GL_ARB_explicit_uniform_location : require layout(location = 5) subroutine uniform color_t Color; Assuming this is the only subroutine uniform, you should be able to set it's value by calling: UniformSubroutinesuiv(GL_FRAGMENT_SHADER, 6, &[0, 0, 0, 0, 0 , subroutin_index]); According to the spec, the values [0]-[4] should be ignored, and the subroutine uniform at location 5 should be set to `subroutin_index`. Mesa will segfault when calling this function like that. Unfortunately, I do not have a complete minimum example program right now (I'm not good with raw opengl), but attached is a fragment shader which can be used to reproduce the problem.
Created attachment 121070 [details] vertex shader which can be used with the fragment shader
Thanks for the bug report. Mesa fix: http://patchwork.freedesktop.org/patch/70667/ Piglit test: http://patchwork.freedesktop.org/patch/70666/
Should be fixed by: commit 86677f101641c75d52577e3cd9e76441b1228b21 mesa: fix segfault in glUniformSubroutinesuiv() From Section 7.9 (SUBROUTINE UNIFORM VARIABLES) of the OpenGL 4.5 Core spec: "The command void UniformSubroutinesuiv(enum shadertype, sizei count, const uint *indices); will load all active subroutine uniforms for shader stage shadertype with subroutine indices from indices, storing indices[i] into the uniform at location i. The indices for any locations between zero and the value of ACTIVE_SUBROUTINE_UNIFORM_LOCATIONS minus one which are not used will be ignored." V2: simplify NULL check suggested by Jason. Acked-by: Jason Ekstrand <jason@jlekstrand.net> Reviewed-by: Dave Airlie <airlied@redhat.com> Cc: "11.0 11.1" mesa-stable@lists.freedesktop.org https://bugs.freedesktop.org/show_bug.cgi?id=93731
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