Update DeallocationStack
for Windows context switch
#15032
Merged
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Calling
LibC.GetCurrentThreadStackLimits
outside the main fiber of a thread will continue to return the original stack top of that thread:This doesn't affect the Crystal runtime because the function is only called once to initialize the main thread, nor the GC because it probes the stack top using
VirtualQuery
. It may nonetheless affect other external libraries because the bad stack will most certainly contain unmapped memory.The correct way is to also update the Win32-specific, non-NT
DeallocationStack
field, since this is the actual stack top that gets returned (see also Wine's implementation).