[Bug 7229] New: Critical section problem in ntdll.dll

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=7229

Summary: Critical section problem in ntdll.dll
           Product: Wine
           Version: 0.9.29.
          Platform: PC
        OS/Version: FreeBSD
            Status: UNCONFIRMED
          Severity: major
          Priority: P2
         Component: wine-winelib
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

There is a race-condition problem in the critical section code in ntdll.dll code.

In critsection.c, for non-linux/x86, non-macosx platforms, fast_wait and
fast_wake are
not implemented. When the first time the semaphore used for waking up waiting
thread(s)
are needed, it will be created. But the code to check if a semaphore is present
is not
protected by critical section by itself. Thus there is a situation that both the
thread
leaves critical section and the thread enters critical create semaphores, that
causes all
waiting threads unable to enter that critical section anymore.

Please see the log that demos this situation.