TCARC.SYS Causes Trap 0xA or Hangs Windows NT

• Microsoft Windows NT Server version 3.51

SYMPTOMS

On symmetric multiprocessor (SMP) configurations using the Thomas Conrad Arcnet driver included with Windows NT a STOP message appears with a Trap 0x0000000A, or your system appears to hang. The following is a stack trace for one of the processors:

ChildEBP RetAddr Args to Child fe36fef4 fbd703a8 00000000 fe4e11e8 00000001 NT!_KiTrap0E+0x25a fe36ff90 fbd5101c fe4e11e8 fe4cf3dc fe58cfe3 NDIS!_ArcFilterDprIndicateReceive+0x253 fe36ffac fbd50d59 fbd50cd6 fe4cd024 fe4d34f8 tcarc!TcarcDpcProcessEnqueuedReceive+0x2e fe36ffc0 fbd60805 fe4cd000 fe561420 fe561468 tcarc!_TcarcDpc+0x83 fe36ffd8 8013906a fe4cd038 fe4cd024 00000000 NDIS!_NdisMDpc+0x39

CAUSE

Both processors have code paths that try to modify the list of received packets at the same time causing the list to get corrupted.

The TCARC.SYS driver contains a list of received packets that is modified by the TcarcEnqueueReceives routine. When a packet is received in an SMP computer, the TcarcEnqueueReceives routine gets called by the TcarcIsr routine on one processor and the TcarcDpc routine on a second processor at the same time.

If the list corruption results in a non-NULL-terminated list the server does not trap but appears to hang. However, technically the server is not hung but is caught in a loop because the TcarcDpc routine continues to indicate packets in the corrupted, non-NULL-terminated, received-packets list because it never encounters a NULL.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.51. This problem was corrected in the latest Windows NT 3.51 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