[Bug 52159] New: 64-bit cygwin gdb.exe and python3.8.exe fail to run

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=52159

Bug ID: 52159
           Summary: 64-bit cygwin gdb.exe and python3.8.exe fail to run
           Product: Wine
           Version: 6.22
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: ntdll
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 71205
  --> https://bugs.winehq.org/attachment.cgi?id=71205
details.txt

This issue can be seen if the workarounds for bug #47808 got applied first.

Both gdb.exe and python3.8.exe fail in the python initialisation.

As far as I see it python allocates 8 bytes for a sem_t structure.
This uninitialized struct is given to sem_init which checks if this
is a previously initialized semaphore by checking
with verifyable_object_isvalid. This check happens inside
a __try/__endtry [2] [3].

That way we end up in RtlUnwindEx, which inspects
NtCurrentTeb()->Tib.ExceptionList.
Unfortunately this list finally contains a pointer to the initial stack,
which cygwin deallocated before [1].

See details.txt.