Bug 109488

Summary:	Mesa 18.3.2 crash on a specific fragment shader (assert triggered) / already fixed on the master branch.
Product:	Mesa	Reporter:	Patrick <patrick9876>
Component:	glsl-compiler	Assignee:	Emil Velikov <emil.l.velikov>
Status:	RESOLVED FIXED	QA Contact:	Intel 3D Bugs Mailing List <intel-3d-bugs>
Severity:	major
Priority:	medium
Version:	18.3
Hardware:	x86-64 (AMD64)
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Patrick 2019-01-28 20:44:27 UTC

The following shader: https://www.shadertoy.com/view/ll3fz4 generates an assert. The issue is fixed after applying the following commit: 76c27e47b90647df047e785d6b3ab5d0d979a1ee available on the master branch.

This commit: 76c27e47b90647df047e785d6b3ab5d0d979a1ee   is likely required on the stable branch too.

With Mesa 18.3.2:
#3  0x00007ffff6ade5f2 in __assert_fail () from /lib64/libc.so.6
#4  0x00007ffff0693686 in (anonymous namespace)::ir_constant_variable_visitor::visit_enter (this=0x7fffffff8680, ir=0x147c470) at glsl/opt_constant_variable.cpp:161
#5  0x00007ffff058962e in ir_call::accept (this=0x147c470, v=0x7fffffff8680) at glsl/ir_hv_accept.cpp:326
#6  0x00007ffff0588968 in visit_list_elements (v=0x7fffffff8680, l=0x14736c0, statement_list=true) at glsl/ir_hv_accept.cpp:55
#7  0x00007ffff0588a96 in ir_loop::accept (this=0x14736a0, v=0x7fffffff8680) at glsl/ir_hv_accept.cpp:89
#8  0x00007ffff0588968 in visit_list_elements (v=0x7fffffff8680, l=0x1471e90, statement_list=true) at glsl/ir_hv_accept.cpp:55
#9  0x00007ffff058883c in ir_hierarchical_visitor::run (this=0x7fffffff8680, instructions=0x1471e90) at glsl/ir_hierarchical_visitor.cpp:364
#10 0x00007ffff06937f5 in do_constant_variable (instructions=0x1471e90) at glsl/opt_constant_variable.cpp:191
#11 0x00007ffff069397a in do_constant_variable_unlinked (instructions=0xc78570) at glsl/opt_constant_variable.cpp:217
#12 0x00007ffff0559c2d in do_common_optimization (ir=0xc78570, linked=false, uniform_locations_assigned=false, options=0xcb2120, native_integers=true) at glsl/glsl_parser_extras.cpp:2243
#13 0x00007ffff0559273 in opt_shader_and_create_symbol_table (ctx=0xcb1160, source_symbols=0x0, shader=0x11db210) at glsl/glsl_parser_extras.cpp:2010
#14 0x00007ffff05594eb in _mesa_glsl_compile_shader (ctx=0xcb1160, shader=0x11db210, dump_ast=false, dump_hir=false, force_recompile=true) at glsl/glsl_parser_extras.cpp:2093
#15 0x00007ffff06a5158 in compile_shaders (ctx=0xcb1160, prog=0x11e92b0) at glsl/shader_cache.cpp:73
#16 0x00007ffff06a585f in shader_cache_read_program_metadata (ctx=0xcb1160, prog=0x11e92b0) at glsl/shader_cache.cpp:232
#17 0x00007ffff05c3b4f in link_shaders (ctx=0xcb1160, prog=0x11e92b0) at glsl/linker.cpp:4879
#18 0x00007ffff0475a05 in _mesa_glsl_link_shader (ctx=0xcb1160, prog=0x11e92b0) at program/ir_to_mesa.cpp:3160
#19 0x00007ffff02fb9e6 in link_program (no_error=false, shProg=0x11e92b0, ctx=0xcb1160) at main/shaderapi.c:1206
#20 link_program_error (ctx=0xcb1160, shProg=0x11e92b0) at main/shaderapi.c:1286
#21 0x00007ffff02fd181 in _mesa_LinkProgram (programObj=16) at main/shaderapi.c:1778
#22 0x00007ffff55e5254 in compile_program (fslocalp=0x7ffff55f35a0 <fsprogram>) at shaderplayopengl.c:299
#23 0x00007ffff55e66bd in setup_createprogram (fslocalp=0x7ffff55f35a0 <fsprogram>, root=1) at shaderplayopengl.c:472
#24 0x00007ffff55e3e4e in context_reset () at libretro-shaderplay.c:1660

Comment 1 Mark Janes 2019-01-28 21:18:59 UTC

Matt, should Timothy's patch have been CC'd to stable when you pushed it?

Comment 2 Matt Turner 2019-01-28 22:33:20 UTC

It wasn't clear to me that it fixed any existing issue.

If we cherry-pick that commit, then we also need to cherry-pick

commit 0862929bf64222e85e8242824aecf05e494c157c
Author: Danylo Piliaiev <danylo.piliaiev@globallogic.com>
Date:   Thu Jan 10 18:16:59 2019 +0200

    glsl: Fix copying function's out to temp if dereferenced by array

as well.

Reassigning to the 18.3 branch maintainer, Emil.

Comment 3 Emil Velikov 2019-02-01 11:17:32 UTC

The patches have landed in 18.3.3 and should address the issue.
Huge thanks for tracking the fix and reporting it.

commit f2c1d7acd0ca56a020a982425523ec8f7fade966
Author: Timothy Arceri <tarceri@itsqueeze.com>
Date:   Mon Apr 9 14:40:40 2018 +1000

    glsl: Copy function out to temp if we don't directly ref a variable


commit 871aea89fd334203c331e7a086738ec59458e1d9
Author: Danylo Piliaiev <danylo.piliaiev@globallogic.com>
Date:   Thu Jan 10 18:16:59 2019 +0200

    glsl: Fix copying function's out to temp if dereferenced by array

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