/*++

    Copyright (c) Microsoft Corporation.  All rights reserved.

Rule Name:

    NdisAllocateMdl

Domain:

    ndis

Rule ID:

    Not Applicable

Description:

    This rule checks that NdisAllocateMdl and NdisFreeMdl are called 
    in alternate order. The ultimate goal is to make sure all Mdls are freed
    when MiniportHaltEx ends.

    The rule uses three different states. state changes when a Mdl is allocated or freed.
    If a Mdl is still allocated when the MiniportHaltEx exits, then the rule will fail. 
    
    Related Rule:

Help Link:

    https://go.microsoft.com/fwlink/?LinkId=507188

--*/




#include "slic_base.h"

state{
   enum {initial, allocated, free} s = initial;
}
watch NdisAllocateMdl.exit.$return;

NdisAllocateMdl.exit[guard $return]
{  
    if ($return != 0)
    {  
        s = allocated;
    }
    
}

NdisFreeMdl.exit[guard $1]
{
    if ( s == free)
    {
        abort "Freeing a MDL that was not allocated.";
    }
  
    s = free;
}

[sdv_MINIPORT_HALT,
sdv_FILTER_DETACH,
sdv_PROTOCOL_UNBIND_ADAPTER_EX].exit
{
    if (s == allocated) 
    {
        abort "You are halting the miniport but still have a MDL allocated.";
    }
}
