| Summary: | INTEL_DEBUG=shader_time always asserts in fs_generator::generate_code() when Mesa is built with --enable-debug (= with asserts) | ||
|---|---|---|---|
| Product: | Mesa | Reporter: | Eero Tamminen <eero.t.tamminen> |
| Component: | Drivers/DRI/i965 | Assignee: | Matt Turner <mattst88> |
| Status: | VERIFIED FIXED | QA Contact: | Intel 3D Bugs Mailing List <intel-3d-bugs> |
| Severity: | normal | ||
| Priority: | medium | ||
| Version: | git | ||
| Hardware: | Other | ||
| OS: | All | ||
| Whiteboard: | |||
| i915 platform: | i915 features: | ||
| Attachments: |
Gdb output on the assert
Gdb output of "shader_time" crash when not using "--enable-debug" asserts Gdb output on second assert |
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Correction: "--enable-debug" didn't affect this. Crash happening later was with older version of Mesa. Created attachment 110413 [details]
Gdb output of "shader_time" crash when not using "--enable-debug" asserts
(disregard previous comment, I did incomplete build)
From the Gdb output one can see that without "--enable-debug" asserts, Mesa with "shader_time" does past-the-array-end access, tries to access data through invalid pointer it got that way, and crashes.
Valgrind doesn't work with Witcher2, so I couldn't get info on whether something goes wrong already earlier.
The assert actually happens with everything, even glxgears. With asserts disable, so far I've seen crash only with Witcher2. Should I file separate bug for that? This is fixed by my [RFC 6/9] i965/fs: Remove force_writemask_all assertion for execsize < 8. patch from Oct 31. It's part of an RFC series, but it could go in separately. The only thing that makes me hesitate is that I don't know how the execution mask works exactly for instructions with execution size < shader dispatch width. Created attachment 110789 [details] Gdb output on second assert (In reply to Matt Turner from comment #4) > This is fixed by my > [RFC 6/9] i965/fs: Remove force_writemask_all assertion for execsize < 8. > patch from Oct 31. > > It's part of an RFC series, but it could go in separately. The only thing > that makes me hesitate is that I don't know how the execution mask works > exactly for instructions with execution size < shader dispatch width. If I remove that assert, the next assert the game hits with "shader_time" is this: witcher2: ../../../../../../src/mesa/drivers/dri/i965/brw_eu_emit.c:285: validate_reg: Assertion `hstride == 0' failed. And the second assert with "shader_time" actually happens also with everything, even glxgears. A test patch that fixes / works around at least the asserts that get triggered with every GL program would be appreciated, so that I can check whether there's some further Witcher2 specific assert. Okay, I'll take a look. Should be fixed by commit 0d8f27eab7b7e8b7a16e76aabd3f6a0ab4880497 Author: Matt Turner <mattst88@gmail.com> Date: Sun Oct 26 22:10:53 2014 -0700 i965/fs: Remove force_writemask_all assertion for execsize < 8. (In reply to Matt Turner from comment #8) > i965/fs: Remove force_writemask_all assertion for execsize < 8. This fixes only the first assert, not the next one which is also triggered by all programs, including glxgears: glxgears: ../../../../../../src/mesa/drivers/dri/i965/brw_eu_emit.c:285: validate_reg: Assertion `hstride == 0' failed. See the Gdb output I attached few months ago. Fixed by these: commit ef9cc7d0c176669c03130abf576f2b700be39514 Author: Kenneth Graunke <kenneth@whitecape.org> Date: Sat Mar 7 23:01:07 2015 -0800 i965/fs: Set force_writemask_all on shader_time instructions. commit f1adc45dbe649cdd4538fb96f6d2a27328bbfba1 Author: Kenneth Graunke <kenneth@whitecape.org> Date: Sun Mar 8 00:13:41 2015 -0800 i965/fs: Set smear on shader_time diff register. Note that shader_time is still producing bogus VS values. You need to revert 15f6118b77cbe42fb997174715bce4c2548aa1f1 then revert 5df88c2096281f416b2738debac1c4c329e29673 for now. Matt's looking into that. The FS code appears to be working. The programs I tested worked -> verified. Witcher2 game I couldn't test as its latest version crashes both with latest Mesa and Ubuntu 14.10 Mesa version for some reason, even without shader_time (don't have now time to look more into that). Could you or Matt comment in this bug when the VS shader_time fixes go upstream? |
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Created attachment 110411 [details] Gdb output on the assert Setup: - HSW GT3e - Ubuntu 14.10 - Latest Mesa (ef7e0b39a24966526b102643523feac765771842), built with --enable-debug Steps: - export following environment variable: INTEL_DEBUG=shader_time - run Witcher2 with above env variable and latest Mesa Result: - Game crashes to an assert More info: - Crash happens only with "shader_time". - If Mesa isn't compiled with --enable-debug, one needs to select "Arena" from the game main menu and only then it will crash --------------- Mesa: User error: GL_INVALID_OPERATION in glRenderbufferStorageMultisample(samples) Mesa: User error: GL_INVALID_OPERATION in glRenderbufferStorageMultisample(samples) Mesa: User error: GL_INVALID_OPERATION in glRenderbufferStorageMultisample(samples) Mesa: User error: GL_INVALID_OPERATION in glRenderbufferStorageMultisample(samples) Mesa: User error: GL_INVALID_OPERATION in glRenderbufferStorageMultisample(samples) Mesa: User error: GL_INVALID_OPERATION in glRenderbufferStorageMultisample(samples) Mesa: User error: GL_INVALID_OPERATION in glRenderbufferStorageMultisample(samples) Mesa: User error: GL_INVALID_OPERATION in glRenderbufferStorageMultisample(samples) glCreateShader is no-op glShaderSource is no-op glCompileShader is no-op glCreateShader is no-op ... glCreateShader is no-op glShaderSource is no-op glCompileShader is no-op witcher2: ../../../../../../src/mesa/drivers/dri/i965/brw_fs_generator.cpp:1567: int fs_generator::generate_code(const cfg_t*, int): Assertion `inst->force_writemask_all' failed. --------------- Gdb output is attached.