[cgutman] 54558: [NDIS] - Call FreeCommonBuffer() synchronously if we're running at PASSIVE_LEVEL to avoid cases where the miniport could be freed before the work item runs

Author: cgutman
Date: Thu Dec  1 23:04:22 2011
New Revision: 54558

URL: http://svn.reactos.org/svn/reactos?rev=54558&view=rev
Log:
[NDIS]
- Call FreeCommonBuffer() synchronously if we're running at PASSIVE_LEVEL to avoid cases where the miniport could be freed before the work item runs

Modified:
    trunk/reactos/drivers/network/ndis/ndis/memory.c

Modified: trunk/reactos/drivers/network/ndis/ndis/memory.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/network/ndis/ndis/m...
==============================================================================
--- trunk/reactos/drivers/network/ndis/ndis/memory.c [iso-8859-1] (original)
+++ trunk/reactos/drivers/network/ndis/ndis/memory.c [iso-8859-1] Thu Dec  1 23:04:22 2011
@@ -239,10 +239,32 @@
 {
   PLOGICAL_ADAPTER Adapter = (PLOGICAL_ADAPTER)MiniportAdapterHandle;
   PMINIPORT_SHARED_MEMORY Memory;
+  PDMA_ADAPTER DmaAdapter = Adapter->NdisMiniportBlock.SystemAdapterObject;

NDIS_DbgPrint(MAX_TRACE,("Called.\n"));

ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
+    
+  /* Call FreeCommonBuffer synchronously if we are at PASSIVE_LEVEL */
+  if (KeGetCurrentIrql() == PASSIVE_LEVEL)
+  {
+      /* We need this case because we free shared memory asynchronously
+       * and the miniport (and DMA adapter object) could be freed before
+       * our work item executes. Lucky for us, the scenarios where the
+       * freeing needs to be synchronous (failed init, MiniportHalt,
+       * and driver unload) are all at PASSIVE_LEVEL so we can just
+       * call FreeCommonBuffer synchronously and not have to worry
+       * about the miniport falling out from under us */
+
+      NDIS_DbgPrint(MID_TRACE,("Freeing shared memory synchronously\n"));
+
+      DmaAdapter->DmaOperations->FreeCommonBuffer(DmaAdapter,
+                                                  Length,
+                                                  PhysicalAddress,
+                                                  VirtualAddress,
+                                                  Cached);
+      return;
+  }

/* Must be NonpagedPool because by definition we're at DISPATCH_LEVEL */
   Memory = ExAllocatePool(NonPagedPool, sizeof(MINIPORT_SHARED_MEMORY));