Add stack check macros.

Source/include/FreeRTOS.h

@@ -118,8 +118,8 @@
 	#error Missing definition:  configUSE_16_BIT_TICKS should be defined in FreeRTOSConfig.h as either 1 or 0.  See the Configuration section of the FreeRTOS API documentation for details.
 #endif
 
-#ifndef INCLUDE_uxGetStackHighWaterMark
+#ifndef INCLUDE_uxTaskGetStackHighWaterMark
-	#define INCLUDE_uxGetStackHighWaterMark 0
+	#define INCLUDE_uxTaskGetStackHighWaterMark 0
 #endif
 
 #ifndef configUSE_RECURSIVE_MUTEXES
@@ -189,6 +189,9 @@
 	#define traceBLOCKING_ON_QUEUE_SEND( pxQueue )
 #endif
 
+#ifndef configCHECK_FOR_STACK_OVERFLOW
+	#define configCHECK_FOR_STACK_OVERFLOW 0
+#endif
 
 /* The following event macros are embedded in the kernel API calls. */
 

Source/include/task.h

@@ -868,9 +868,9 @@ unsigned portLONG ulTaskEndTrace( void );
 
 /**
  * task.h
- * <PRE>unsigned portBASE_TYPE uxGetStackHighWaterMark( void );</PRE>
+ * <PRE>unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( void );</PRE>
  *
- * INCLUDE_uxGetStackHighWaterMark must be set to 1 in FreeRTOSConfig.h for
+ * INCLUDE_uxTaskGetStackHighWaterMark must be set to 1 in FreeRTOSConfig.h for
  * this function to be available.
  *
  * Returns the high water mark for the stack of the calling task.  That is,
@@ -878,7 +878,7 @@ unsigned portLONG ulTaskEndTrace( void );
  * started.  The small the returned number the closer the task has come
  * to overflowing its stack.
  */
-unsigned portBASE_TYPE uxGetStackHighWaterMark( void );
+unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( void );
 
 /*-----------------------------------------------------------
  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES

Source/tasks.c

@@ -25,11 +25,11 @@
 
 	***************************************************************************
 
-	Please ensure to read the configuration and relevant port sections of the 
+	Please ensure to read the configuration and relevant port sections of the
 	online documentation.
 
 	+++ http://www.FreeRTOS.org +++
-	Documentation, latest information, license and contact details.  
+	Documentation, latest information, license and contact details.
 
 	+++ http://www.SafeRTOS.com +++
 	A version that is certified for use in safety critical systems.
@@ -40,180 +40,6 @@
 	***************************************************************************
 */
 
-/*
-Changes from V1.00:
-	
-	+ Call to portRESTORE_CONTEXT has been removed.  The first context
-	  switch is now performed within sPortStartScheduler().
-
-Changes from V1.01:
-
-	+ More use of 8bit data types.
-	+ Function name prefixes changed where the data type returned has changed.
-	+ configUSE_TRACE_FACILITY is no longer defined by default.
-
-Changes from V1.2.0
-
-	+ Introduced ucTopReadyPriority.  This tracks the highest priority ready
-	  queue that contains a valid TCB and thus makes the context switch
-	  slightly faster.
-
-	+ prvAddTaskToReadyQueue() has been made a macro.
-
-Changes from V1.2.6
-
-	+ Added conditional compilation directives.
-	+ Extended API.
-	+ Rearranged function order.
-	+ Creating a task now causes a context switch if the task being created
-	  has a higher priority than the calling task - assuming the kernel is
-	  running.
-	+ vTaskDelete() now only causes a context switch if the calling task is
-	  the task being deleted.
-
-Changes from V2.0.0
-
-	+ Allow the type of the tick count to be 16 or 32 bits.
-	+ Introduce xPendingReadyList feature to allow the time interrupts have to
-	  be disabled to be minimised.
-	+ Remove the #if( INCLUDE_vTaskSuspendAll ) statements.  vTaskSuspendAll()
-	  is now always included as it is used by the scheduler itself.
-
-Changes from V2.1.0
-
-	+ Bug fix - pxCurrentTCB is now initialised before the call to
-	  prvInitializeTaskLists().  Previously pxCurrentTCB could be accessed
-	  while null.
-
-Changed from V2.1.1
-
-	+ Change to where lStackSize is declared within sTaskCreate() to prevent
-	  compiler warnings with 8051 port.
-
-Changes from V2.2.0
-
-	+ Explicit use of 'signed' qualifier on portCHAR types added.
-	+ Changed odd calculation of initial pxTopOfStack value when
-	  portSTACK_GROWTH < 0.
-	+ Removed pcVersionNumber definition.
-
-Changes from V2.5.3
-
-	+ cTaskResumeAll() modified to ensure it can be called prior to the task
-	  lists being initialised.
-
-Changes from V2.5.5
-
-	+ Added API function vTaskDelayUntil().
-	+ Added INCLUDE_vTaskDelay conditional compilation.
-
-Changes from V2.6.0
-
- 	+ Updated the vWriteTraceToBuffer macro to always be 4 byte aligned so it
-	  can be used on ARM architectures.
-	+ tskMAX_TASK_NAME_LEN definition replaced with the port specific
-	  configMAX_TASK_NAME_LEN definition.
-	+ Removed the call to strcpy when copying across the task name into the
-	  TCB.
-	+ Added ucTasksDeleted variable to prevent vTaskSuspendAll() being called
-	  too often in the idle task.
-
-Changes between V3.0.0 and V2.6.1
-
-	+ When resuming the scheduler a yield is performed if either a tick has
-	  been missed, or a task is moved from the pending ready list into a ready
-	  list.  Previously a yield was not performed on this second condition.
-	+ Introduced the type portBASE_TYPE.  This necessitates several API
-	  changes.
-	+ Removed the sUsingPreemption variable.  The constant defined in
-	  portmacro.h is now used directly.
-	+ The idle task can now include an optional hook function - and no longer
-	  completes its time slice if other tasks with equal priority to it are
-	  ready to run.
-	+ See the FreeRTOS.org documentation for more information on V2.x.x to
-	  V3.x.x modifications.
-
-Changes from V3.1.1
-
-	+ Modified vTaskPrioritySet() and vTaskResume() to allow these functions to
-	  be called while the scheduler is suspended.
-	+ Corrected the task ordering within event lists.
-
-Changes from V3.2.0
-
-	+ Added function xTaskGetCurrentTaskHandle().
-
-Changes from V3.2.4
-
-	+ Changed the volatile declarations on some variables to reflect the 
-	  changes to the list definitions.
-	+ Changed the order of the TCB definition so there is commonality between
-	  the task control block and a co-routine control block.
-	+ Allow the scheduler to be started even if no tasks other than the idle
-	  task has been created.  This allows co-routines to run even when no tasks
-	  have been created.
-	+ The need for a context switch is now signalled if a task woken by an 
-	  event has a priority greater or equal to the currently running task.
-	  Previously this was only greater than.
-
-Changes from V4.0.0
-
-	+ Added the xMissedYield handling.
-
-Changes from V4.0.1
-
-	+ The function vTaskList() now suspends the scheduler rather than disabling
-	  interrupts during the creation of the task list.  
-	+ Allow a task to delete itself by passing in its own handle.  Previously 
-	  this could only be done by passing in NULL.
-	+ The tick hook function is now called only within a tick isr.  Previously
-	  it was also called when the tick function was called during the scheduler
-	  unlocking process.
-
-Changes from V4.0.3
-
-	+ Extra checks have been placed in vTaskPrioritySet() to avoid unnecessary
-	  yields.
-
-Changed from V4.0.4
-
-	+ Bug fix:  The 'value' of the event list item is updated when the priority
-	  of a task is changed.  Previously only the priority of the TCB itself was
-	  changed.
-	+ When resuming a task a check is first made to see if the task is actually
-	  suspended.
-	+ vTaskPrioritySet() and vTaskResume() no longer use the event list item.
-	  This has not been necessary since V4.0.1 when the xMissedYield handling
-	  was added.
-	+ Implement xTaskResumeFromISR().
-
-Changes from V4.0.5
-
-	+ Added utility functions and xOverflowCount variable to facilitate the
-	  queue.c changes.
-
-Changes from V4.1.2
-	
-	+ Tasks that block on events with a timeout of portMAX_DELAY are now
-	  blocked indefinitely if configINCLUDE_vTaskSuspend is defined. 
-	  Previously portMAX_DELAY was just the longest block time possible.
-
-Changes from V4.1.3
-
-	+ Very small change made to xTaskCheckForTimeout() as a result of the 
-	SafeRTOS testing.  This corrects the case where the function can return an
-	invalid value - but only in an extremely unlikely scenario.
-
-Changes since V4.3.1:
-
-	+ Added xTaskGetSchedulerState() function.
-	+ Added prvIsTaskSuspended() to take into account the Occurrence of
-	  vTaskResume() or vTaskResumeFromISR() being called passing in the
-	  handle of a task that appears in the Suspended list only because it
-	  is blocked on an event without a timeout being specified.
-	+ Updated xTaskCheckForTimeout() to take into account that tasks blocked
-	  using the Suspended list should never time out.
-*/
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -345,6 +171,8 @@ static volatile portBASE_TYPE xNumOfOverflows					= ( portBASE_TYPE ) 0;
 
 #endif
 
+/*-----------------------------------------------------------*/
+
 /*
  * Macro that writes a trace of scheduler activity to a buffer.  This trace
  * shows which task is running when and is very useful as a debugging tool.
@@ -382,7 +210,7 @@ static volatile portBASE_TYPE xNumOfOverflows					= ( portBASE_TYPE ) 0;
 	#define vWriteTraceToBuffer()
 
 #endif
-
+/*-----------------------------------------------------------*/
 
 /*
  * Place the task represented by pxTCB into the appropriate ready queue for
@@ -398,7 +226,8 @@ static volatile portBASE_TYPE xNumOfOverflows					= ( portBASE_TYPE ) 0;
 		uxTopReadyPriority = pxTCB->uxPriority;																	\
 	}																											\
 	vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );	\
-}		
+}
+/*-----------------------------------------------------------*/		
 
 /*
  * Macro that looks at the list of tasks that are currently delayed to see if
@@ -424,9 +253,82 @@ register tskTCB *pxTCB;																								\
 		{																											\
 			vListRemove( &( pxTCB->xEventListItem ) );																\
 		}																											\
-		prvAddTaskToReadyQueue( pxTCB );														\
+		prvAddTaskToReadyQueue( pxTCB );																			\
 	}																												\
-}																							
+}
+/*-----------------------------------------------------------*/
+
+/*
+ * Call the stack overflow hook function if the stack of the task being swapped
+ * out is currently overflowed, or looks like it might have overflowed in the
+ * past.
+ *
+ * Setting configCHECK_FOR_STACK_OVERFLOW to 1 will cause the macro to check
+ * the current stack state only - comparing the current top of stack value to
+ * the stack limit.  Setting configCHECK_FOR_STACK_OVERFLOW to greater than 1
+ * will also cause the last few stack bytes to be checked to ensure the value
+ * to which the bytes were set when the task was created have not been 
+ * overwritten.  Note this second test does not guarantee that an overflown
+ * stack will always be recognised.
+ */
+
+#if( configCHECK_FOR_STACK_OVERFLOW == 0 )
+
+	/* FreeRTOSConfig.h is not set to check for stack overflows. */
+	#define taskCHECK_FOR_STACK_OVERFLOW()
+
+#endif /* configCHECK_FOR_STACK_OVERFLOW == 0 */
+
+#if( ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) )
+
+	/* This is an invalid setting. */
+	#error configCHECK_FOR_STACK_OVERFLOW can only be set to a non zero value on architectures where the stack grows down from high memory.
+
+#endif /* ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) */
+
+#if( configCHECK_FOR_STACK_OVERFLOW == 1 )
+
+	/* Only the current stack state is to be checked. */
+	#define taskCHECK_FOR_STACK_OVERFLOW()																\
+	{																									\
+	extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );		\
+																										\
+		/* Is the currently saved stack pointer within the stack limit? */								\
+		if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )										\
+		{																								\
+			vApplicationStackOverflowHook( pxCurrentTCB, pxCurrentTCB->pcTaskName );					\
+		}																								\
+	}
+
+#endif /* configCHECK_FOR_STACK_OVERFLOW == 1 */
+
+#if( configCHECK_FOR_STACK_OVERFLOW > 1 )
+
+	/* Both the current statck state and the stack fill bytes are to be checked. */
+	#define taskCHECK_FOR_STACK_OVERFLOW()																											\
+	{																																				\
+	extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );													\
+	static const unsigned portCHAR ucExpectedStackBytes[] = {	tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,		\
+																tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,		\
+																tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,		\
+																tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,		\
+																tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE };	\
+																																					\
+		/* Is the currently saved stack pointer within the stack limit? */																			\
+		if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )																					\
+		{																																			\
+			vApplicationStackOverflowHook( pxCurrentTCB, pxCurrentTCB->pcTaskName );																\
+		}																																			\
+																																					\
+		/* Has the extremity of the task stack ever been written over? */																			\
+		if( memcmp( pxCurrentTCB->pxStack, ucExpectedStackBytes, sizeof( ucExpectedStackBytes ) ) != 0 )											\
+		{																																			\
+			vApplicationStackOverflowHook( pxCurrentTCB, pxCurrentTCB->pcTaskName );																\
+		}																																			\
+	}
+
+#endif /* #if( configCHECK_FOR_STACK_OVERFLOW > 1 ) */
+/*-----------------------------------------------------------*/
 
 /*
  * Several functions take an xTaskHandle parameter that can optionally be NULL,
@@ -508,7 +410,7 @@ static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );
  * This function determines the 'high water mark' of the task stack by
  * determining how much of the stack remains at the original preset value.
  */
-#if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxGetStackHighWaterMark == 1 ) )
+#if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )
 
 	unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );
 
@@ -528,8 +430,6 @@ static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );
 
 
 
-
-
 /*-----------------------------------------------------------
  * TASK CREATION API documented in task.h
  *----------------------------------------------------------*/
@@ -663,7 +563,7 @@ tskTCB * pxNewTCB;
 
 		taskENTER_CRITICAL();
 		{
-			/* Ensure a yield is performed if the current task is being 
+			/* Ensure a yield is performed if the current task is being
 			deleted. */
 			if( pxTaskToDelete == pxCurrentTCB )
 			{
@@ -697,7 +597,7 @@ tskTCB * pxNewTCB;
 		taskEXIT_CRITICAL();
 
 		/* Force a reschedule if we have just deleted the current task. */
-		if( xSchedulerRunning != pdFALSE ) 
+		if( xSchedulerRunning != pdFALSE )
 		{
 			if( ( void * ) pxTaskToDelete == NULL )
 			{
@@ -912,7 +812,7 @@ tskTCB * pxNewTCB;
 			{
 				/* The priority change may have readied a task of higher
 				priority than the calling task. */
-				if( uxNewPriority > uxCurrentPriority ) 
+				if( uxNewPriority > uxCurrentPriority )
 				{
 					if( pxTask != NULL )
 					{
@@ -985,7 +885,7 @@ tskTCB * pxNewTCB;
 
 		taskENTER_CRITICAL();
 		{
-			/* Ensure a yield is performed if the current task is being 
+			/* Ensure a yield is performed if the current task is being
 			suspended. */
 			if( pxTaskToSuspend == pxCurrentTCB )
 			{
@@ -1407,8 +1307,8 @@ inline void vTaskIncrementTick( void )
 		{
 			xList *pxTemp;
 
-			/* Tick count has overflowed so we need to swap the delay lists.  
+			/* Tick count has overflowed so we need to swap the delay lists.
-			If there are any items in pxDelayedTaskList here then there is 
+			If there are any items in pxDelayedTaskList here then there is
 			an error! */
 			pxTemp = pxDelayedTaskList;
 			pxDelayedTaskList = pxOverflowDelayedTaskList;
@@ -1423,7 +1323,7 @@ inline void vTaskIncrementTick( void )
 	{
 		++uxMissedTicks;
 
-		/* The tick hook gets called at regular intervals, even if the 
+		/* The tick hook gets called at regular intervals, even if the
 		scheduler is locked. */
 		#if ( configUSE_TICK_HOOK == 1 )
 		{
@@ -1514,6 +1414,8 @@ void vTaskSwitchContext( void )
 		return;
 	}
 
+	taskCHECK_FOR_STACK_OVERFLOW();
+
 	/* Find the highest priority queue that contains ready tasks. */
 	while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )
 	{
@@ -1548,7 +1450,7 @@ portTickType xTimeToWake;
 
 
 	#if ( INCLUDE_vTaskSuspend == 1 )
-	{			 
+	{			
 		if( xTicksToWait == portMAX_DELAY )
 		{
 			/* Add ourselves to the suspended task list instead of a delayed task
@@ -1933,7 +1835,8 @@ tskTCB *pxNewTCB;
 #endif
 /*-----------------------------------------------------------*/
 
-#if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxGetStackHighWaterMark == 1 ) )
+#if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )
+
 	unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )
 	{
 	register unsigned portSHORT usCount = 0;
@@ -1948,14 +1851,17 @@ tskTCB *pxNewTCB;
 
 		return usCount;
 	}
+
 #endif
 /*-----------------------------------------------------------*/
 
-#if ( INCLUDE_uxGetStackHighWaterMark == 1 )
+#if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )
-	unsigned portBASE_TYPE uxGetStackHighWaterMark( void )
+
+	unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( void )
 	{
 		return usTaskCheckFreeStackSpace( pxCurrentTCB->pxStack );
 	}
+
 #endif
 /*-----------------------------------------------------------*/