STOP Message Occurs Calling GetThreadContext/SetThreadContext

• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server version 4.0

SYMPTOMS

If you run a program that calls to GetThreadContext() or SetThreadContext() with certain bad kernel mode addresses (high bit set) specified for the context recorn, a Stop message with a blue screen appears and your computer stops responding (hangs).

The stop code is a function of the type of illegal address passed to the function.

CAUSE

A field in the context structure is referenced within a try/except, but without first doing a probe.

Almost all bad kernel addresses are caught by the exception handling mechanism, but there are classes of addresses which the system declares as totally invalid and which should never generate a fault. If one of these addresses is referenced and a fault occurs, the system crashes on purpose.

WORKAROUND

Obtain the fix mentioned below or wait for the next Service Pack.

To work around this problem, stop using the software that calls GetThreadContext or SetThreadContext with the illegal address value.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0. This problem was corrected in the latest Windows NT 4.0 U.S. Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K