Bug 91039

Summary: [d3d9] D3D9 state tracker crashes due to stack misalignment if Mesa is compiled with -mfpmath=sse
Product: Mesa Reporter: Itzamna <xamaniqinqu>
Component: Gallium/StateTracker/galliumnineAssignee: mesa-dev
Status: RESOLVED MOVED QA Contact: mesa-dev
Severity: normal    
Priority: medium CC: r9ku1q, xamaniqinqu
Version: 10.6   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:

Description Itzamna 2015-06-20 19:06:20 UTC 
Description: 
The "Nine" D3D9 state tracker crashes when Wine loads any D3D program if Mesa is compiled with -mfpmath=sse. This is because the Linux ABI assumes a stack alignment to 16 bytes, whereas the Win32 ABI assumes a stack alignment to 4 bytes. This causes a stack misalignment and thus a general protection fault.


Additional information: 
Also see the following external bug reports:

https://bugs.winehq.org/show_bug.cgi?id=22475
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40838


Specifications:
OS: Gentoo GNU/Linux x86_64
Kernel version: Linux 4.0.4-hardened-r3
Mesa version: 10.6.0


Solution:
The crashes no longer occur when Mesa's stack is realigned to 4 bytes. Therefore, always pass -mstackrealign to CFLAGS if -mfpmath=sse is enabled; this should probably be handled in the configure script.
Comment 1 Itzamna 2015-06-20 19:27:19 UTC 
(In reply to Itzamna from comment #0)

> Solution:
> The crashes no longer occur when Mesa's stack is realigned to 4 bytes.
> Therefore, always pass -mstackrealign to CFLAGS if -mfpmath=sse is enabled;
> this should probably be handled in the configure script.

Erratum: -mstackrealign realigns the incoming (4 byte-aligned) stack to 16 bytes, see https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html .
Comment 2 Axel Davy 2018-05-09 06:10:53 UTC 
To my knowledge we've been handling function stack realignment in nine for a few years now, and thus I assume this issue is solved. Do you confirm ?
Comment 3 GitLab Migration User 2019-09-18 17:52:49 UTC 
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