Fix stack overflow protection mechanism

[alexey-katranov]

The stack size is incorrectly supposed to be 4 MB on Windows. However, MSDN states that "The default stack reservation size used by the linker is 1 MB". It leads to two issues:

1. The stack overflow protection mechanism does not work on Windows properly, i.e. stealing can be allowed even if the stack is fully consumed.
2. The stack anchor calculation might overflow and block the stealing completely (that is reproduced in Some tests failed on MSVC 2019 (x64 build) #478 (comment)) due to main thread stack mapping on low address).

The fix changes the assumption to 1 MB on Windows. If compiled with modern Windows, the system API is used to query stack size instead of the assumption.

[alexey-katranov]

To support Windows 7, consider using NtCurrentTeb to query StackLimit from NT_TIB.

[alexey-katranov]

While it seems we can emulate GetCurrentThreadStackLimits via TIB, we should use DeallocationStack (not
StackLimit) for the real stack address. The implementation GetCurrentThreadStackLimits does the same (x64 implementation):

mov         r8,qword ptr gs:[30h]      // get TIB
mov         rax,qword ptr [r8+1478h]   // TIB + 1478h is DeallocationStack
mov         qword ptr [rcx],rax        // return LowLimit
mov         rax,qword ptr [r8+8]       // TIB + 8h is StackBase
mov         qword ptr [rdx],rax        // return HighLimit
ret

So, on x86_32 the DeallocationStack offset will be another and it seems the current approach is the lesser of two evils.

[phprus]

I had no crashes on tests on Windows 7 (x86 and x64) after applying this patch.
The simple 1 MB limit works in all my Windows 7 environments.

[anton-potapov]

Suggested change

	ULONG_PTR hi, lo;
	GetCurrentThreadStackLimits(&lo, &hi);
	return std::size_t(hi - lo);
	ULONG_PTR hi, lo;
	GetCurrentThreadStackLimits(&lo, &hi);
	return static_cast<std::size_t>(hi - lo);

[anton-potapov]

I believe type cast is not needed here at whole, but if you wish...

[phprus]

Is there any progress?

[alexey-katranov]

Thank you for the reminder, unfortunately, there is no any progress.

[anton-potapov]

LGTM