Details
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Type:
Bug
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Status: Closed
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Priority:
Critical
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Resolution: Fixed
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Affects Version/s: None
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Fix Version/s: None
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Component/s: None
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Labels:
Description
In Maria 5.2 PBXT crashes directly on startup
with this callstack.
mysqld.exe!_setjmp()
mysqld.exe!xt_create_thread()[thread_xt.cc:1425]
mysqld.exe!xt_init_threading()[thread_xt.cc:1211]
mysqld.exe!pbxt_init()[ha_pbxt.cc:1203]
mysqld.exe!ha_initialize_handlerton()[handler.cc:431]
...
Disassembly reveals sse instruction that requires 16 bit aligment on misaligned address.
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Re: pbxt crashes on Windows 64 (misalignment on SSE instruciton)
s.a http://lists.askmonty.org/pipermail/commits/2011-February/001256.html
Re: pbxt crashes on Windows 64 (misalignment on SSE instruciton)
Fixed in MartiaDB (long ago, no idea which release)
Re: pbxt crashes on Windows 64 (misalignment on SSE instruciton)
Vladislav,
I added an aligner to PBXT memory debugging structure, so that now PBXT debug malloc now works fine in 86x64 mode (see the linked lp:pbxt branch). If you're going to merge it to Maria I can push Maria branch with the fix.
Re: pbxt crashes on Windows 64 (misalignment on SSE instruciton)
Windows has debug malloc, it is malloc in debug C runtime. Besides, it has pageheap and application verifier as debug mallocs for release compilation. Personally I miss the point of adding yet another layer of debug mallocs to already existing ones.
Launchpad bug id: 688404
Re: pbxt crashes on Windows 64 (misalignment on SSE instruciton)
This affects debug compilation.
Analysis shows that the problematic area is memory debug functionality in PBXT that returns 8 byte aligned pointers (due to 8 byte prefix). The critical place here is
self = (XTThreadPtr) xt_calloc_ns(sizeof(XTThreadRec));
this returns 8 byte aligned (read 16 byte unaligned) pointer. This structure contains jmp_buf array, for which alignment requirements is 16 byte. When setjmp issues instruction which operates on 16 byte aligned memory, it crashes.
the instruction in question is
movdqa xmmword ptr [rcx+60h],xmm6