[tfaber] 61113: [SERIAL] - Fix a race condition

Author: tfaber
Date: Thu Nov 28 14:32:04 2013
New Revision: 61113

URL: http://svn.reactos.org/svn/reactos?rev=61113&view=rev
Log:
[SERIAL]
- Fix a race condition

Modified:
    trunk/reactos/drivers/serial/serial/devctrl.c

Modified: trunk/reactos/drivers/serial/serial/devctrl.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/serial/serial/devc…
==============================================================================
--- trunk/reactos/drivers/serial/serial/devctrl.c	[iso-8859-1] (original)
+++ trunk/reactos/drivers/serial/serial/devctrl.c	[iso-8859-1] Thu Nov 28 14:32:04 2013
@@ -827,12 +827,10 @@
 				Status = STATUS_INVALID_PARAMETER;
 			else
 			{
-				/* FIXME: Race condition here:
-				 * If an interrupt comes before we can mark the Irp
-				 * as pending, it might be possible to complete the
-				 * Irp before pending it, leading to a crash! */
+				IoMarkIrpPending(Irp);
+
 				WaitingIrp = InterlockedCompareExchangePointer(
-					(PVOID)&DeviceExtension->WaitOnMaskIrp,
+					&DeviceExtension->WaitOnMaskIrp,
 					Irp,
 					NULL);
 
@@ -841,13 +839,11 @@
 				{
 					/* Unable to have a 2nd pending IRP for this IOCTL */
 					WARN_(SERIAL, "Unable to pend a second IRP for
IOCTL_SERIAL_WAIT_ON_MASK\n");
-					Status = STATUS_INVALID_PARAMETER;
+					Irp->IoStatus.Information = 0;
+					Irp->IoStatus.Status = STATUS_INVALID_PARAMETER;
+					IoCompleteRequest(Irp, IO_NO_INCREMENT);
 				}
-				else
-				{
-					Status = STATUS_PENDING;
-					/* FIXME: immediately return if a wait event already occurred */
-				}
+				return STATUS_PENDING;
 			}
 			break;
 		}