1 files changed, 172 insertions, 0 deletions
diff --git a/FreeRTOS/Test/CBMC/proofs/Task/TaskDelete/tasks_test_access_functions.h b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelete/tasks_test_access_functions.h
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+++ b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelete/tasks_test_access_functions.h
@@ -0,0 +1,172 @@
+/*
+ * FreeRTOS memory safety proofs with CBMC.
+ * Copyright (C) 2019 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * http://aws.amazon.com/freertos
+ * http://www.FreeRTOS.org
+ */
+
+#include "cbmc.h"
+
+/*
+ * We allocate a TCB and set some members to basic values
+ */
+TaskHandle_t xUnconstrainedTCB( void )
+{
+	TCB_t * pxTCB = pvPortMalloc(sizeof(TCB_t));
+	uint8_t ucStaticAllocationFlag;
+
+	if ( pxTCB == NULL )
+		return NULL;
+
+	__CPROVER_assume( pxTCB->uxPriority < configMAX_PRIORITIES );
+
+	vListInitialiseItem( &( pxTCB->xStateListItem ) );
+	vListInitialiseItem( &( pxTCB->xEventListItem ) );
+
+	listSET_LIST_ITEM_OWNER( &( pxTCB->xStateListItem ), pxTCB );
+	listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );
+
+	if ( nondet_bool() )
+	{
+		listSET_LIST_ITEM_VALUE( &( pxTCB->xStateListItem ), pxTCB->uxPriority );
+	}
+	else
+	{
+		listSET_LIST_ITEM_VALUE( &( pxTCB->xStateListItem ), portMAX_DELAY );
+	}
+
+	if ( nondet_bool() )
+	{
+		listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( TickType_t ) configMAX_PRIORITIES - ( TickType_t ) pxTCB->uxPriority );
+	}
+	else
+	{
+		listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), portMAX_DELAY );
+	}
+
+	pxTCB->pxStack = ( StackType_t * ) pvPortMalloc( ( ( ( size_t ) STACK_DEPTH ) * sizeof( StackType_t ) ) );
+	if ( pxTCB->pxStack == NULL )
+	{
+		vPortFree( pxTCB );
+		return NULL;
+	}
+
+	__CPROVER_assume( ucStaticAllocationFlag <= tskSTATICALLY_ALLOCATED_STACK_AND_TCB );
+	__CPROVER_assume( ucStaticAllocationFlag >= tskDYNAMICALLY_ALLOCATED_STACK_AND_TCB );
+	pxTCB->ucStaticallyAllocated = ucStaticAllocationFlag;
+
+	return pxTCB;
+}
+
+/*
+ * We set the values of relevant global
+ * variables to nondeterministic values
+ */
+void vSetGlobalVariables()
+{
+	xSchedulerRunning = nondet_basetype();
+}
+
+/*
+ * We initialise and fill the task lists so coverage is optimal.
+ * This initialization is not guaranteed to be minimal, but it
+ * is quite efficient and it serves the same purpose
+ */
+BaseType_t xPrepareTaskLists( TaskHandle_t * xTask )
+{
+	TCB_t * pxTCB = NULL;
+
+	__CPROVER_assert_zero_allocation();
+
+	prvInitialiseTaskLists();
+
+	/*
+	 * The task handle passed to TaskDelete can be NULL. In that case, the
+	 * task to delete is the one in `pxCurrentTCB`, see the macro `prvGetTCBFromHandle`
+	 * in line 1165 (tasks.c) for reference. For that reason, we provide a similar
+	 * initialization for an arbitrary task `pxTCB` and `pxCurrentTCB`.
+	 */
+
+	pxTCB = xUnconstrainedTCB();
+	if ( pxTCB != NULL )
+	{
+		if ( nondet_bool() )
+		{
+			TCB_t * pxOtherTCB;
+			pxOtherTCB = xUnconstrainedTCB();
+			/*
+			 * Nondeterministic insertion of another TCB in the same list
+			 * to guarantee coverage in line 1174 (tasks.c)
+			 */
+			if ( pxOtherTCB != NULL )
+			{
+				vListInsert( &xPendingReadyList, &( pxOtherTCB->xStateListItem ) );
+			}
+		}
+		vListInsert( &xPendingReadyList, &( pxTCB->xStateListItem ) );
+
+		/*
+		 * Nondeterministic insertion of an event list item to guarantee
+		 * coverage in lines 1180-1184 (tasks.c)
+		 */
+		if ( nondet_bool() )
+		{
+			vListInsert( pxDelayedTaskList, &( pxTCB->xEventListItem ) );
+		}
+	}
+
+	/* Note that `*xTask = NULL` can happen here, but this is fine -- `pxCurrentTCB` will be used instead */
+	*xTask = pxTCB;
+
+	/*
+	 * `pxCurrentTCB` must be initialized the same way as the previous task, but an
+	 * allocation failure cannot happen in this case (i.e., if the previous task is NULL)
+	 */
+	pxCurrentTCB = xUnconstrainedTCB();
+	if ( pxCurrentTCB == NULL )
+	{
+		return pdFAIL;
+	}
+
+	if ( nondet_bool() )
+	{
+		TCB_t * pxOtherTCB;
+		pxOtherTCB = xUnconstrainedTCB();
+		if ( pxOtherTCB != NULL )
+		{
+			vListInsert( &pxReadyTasksLists[ pxOtherTCB->uxPriority ], &( pxOtherTCB->xStateListItem ) );
+		}
+	}
+	vListInsert( &pxReadyTasksLists[ pxCurrentTCB->uxPriority ], &( pxCurrentTCB->xStateListItem ) );
+
+	/* Use of this macro ensures coverage on line 185 (list.c) */
+	listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB , &pxReadyTasksLists[ pxCurrentTCB->uxPriority ] );
+
+	if ( nondet_bool() )
+	{
+		vListInsert( pxDelayedTaskList, &( pxCurrentTCB->xEventListItem ) );
+	}
+
+	return pdPASS;
+}