Merge branch 'main' into agent/optimize-gcc-arm-cm4f-base-type-access

History.txt

@@ -1,5 +1,140 @@
 Documentation and download available at https://www.FreeRTOS.org/
 
+Changes between FreeRTOS V11.3.0 and FreeRTOS V11.3.1 released August 2026
+
+    + Add Symmetric Multiprocessing (SMP) support to the Armv8-M ports for the
+      GCC, ArmClang and IAR toolchains. This adds per core critical nesting
+      state, spinlocks, inter-core yield and wakeup using SEV/WFE, primary and
+      secondary core bring up synchronization, and a core safe PendSV context
+      switch. Single core builds are unchanged. We thank @AhmedIsmail02 for
+      their contribution.
+    + Add new xTaskPeriodicDelay API for periodic tasks. It supersedes
+      xTaskDelayUntil by preventing run away of pxPreviousWakeTime, catching up
+      skipped periods immediately while returning the number of periods skipped,
+      and returning 0 when not enough ticks have elapsed. We thank @ntd for
+      their contribution.
+    + Add uxTaskCallForEachTask API, which invokes a caller supplied callback
+      for each task in the system, and refactor uxTaskGetSystemState to use it.
+      We thank @DRNadler for their contribution.
+    + Add configIDLE_AFFINITY configuration option, which pins each Idle task to
+      its corresponding core in SMP systems. It defaults to 0, which allows the
+      scheduler to run Idle tasks on any available core. We thank @rus084 for
+      their contribution.
+    + Add validation to SecureContext_AllocateContext in the ARMv8-M secure side
+      ports to ensure that the requested secure stack size plus the stack seal
+      size does not overflow before allocating. We thank Jordan Mecom (Block,
+      Inc.) for reporting this issue.
+    + Add assertions to vQueueDelete to check that no tasks are blocked on the
+      queue being deleted.
+    + Add a link to the FreeRTOS Kernel threat model in SECURITY.md.
+    + Add documentation clarifying that the MemoryRegion_t ulParameters macros
+      are port specific, so applications must use the tskMPU_REGION_* or
+      portMPU_REGION_* values that match their MPU port. We thank @Old-Ding for
+      their contribution.
+    + Add a comment documenting that a privileged task must revoke access
+      permissions before deleting a kernel object when using Access Control
+      Lists.
+    + Update the ARM_CRx_No_GIC port to declare vPortYield as a weak symbol so
+      that devices with a dedicated software interrupt register can substitute
+      their own yield trigger. The default behavior is unchanged. We thank
+      @maximdeclercq for their contribution.
+    + Update the FreeRTOSConfig.h template to use a 32-bit tick type, which
+      avoids compiler warnings on Windows where a 64-bit tick resolves to
+      unsigned long long.
+    + Update the deprecated CMake configuration warning to use INTERFACE rather
+      than PUBLIC for the freertos_config interface library. We thank @Isla-jq
+      for their contribution.
+    + Fix vPortFreeSecureContext in the ARMv8-M ports to read xSecureContext at
+      the correct offset. When the MPU is enabled, the first item in the TCB is
+      the stored context location rather than the top of stack, so
+      xSecureContext is located at a negative offset from that position.
+    + Fix SecureContext_AllocateContext in the ARMv8-M secure side ports to
+      reject a secure stack size smaller than the stack seal size.
+    + Fix SecureContext_FreeContext in the ARMv8-M secure side ports to refuse
+      to free the secure context that is currently loaded, as indicated by
+      PSPLIM. Freeing it left the running task referencing freed secure memory.
+      The task handle supplied by the non-secure side is untrusted, so it is
+      now used only as an additional ownership check.
+    + Fix the ARMv8-M ports to service the portSVC_START_SCHEDULER and
+      portSVC_FREE_SECURE_CONTEXT supervisor calls only when they are raised
+      from privileged code. When the MPU is enabled, both requests are now
+      ignored unless the calling program counter lies within the privileged
+      functions section.
+    + Fix a type confusion in xQueueAddToSet by verifying that the object
+      passed as the queue set really is a queue set, that is, that its item
+      size is sizeof( Queue_t * ). Passing an ordinary queue now returns
+      pdFAIL rather than allowing prvNotifyQueueSetContainer to copy item size
+      bytes from a single pointer on the stack.
+    + Fix xTimerGenericCommandFromTask to validate the lower bound of
+      xCommandID in addition to the existing upper bound, so that only the
+      valid task command range from tmrCOMMAND_START_DONT_TRACE to
+      tmrCOMMAND_DELETE is accepted. Rejected commands return pdFAIL, and
+      behavior for valid commands and for xTimerGenericCommandFromISR is
+      unchanged.
+    + Fix a kernel object pool entry leak by adding an MPU wrapper for the
+      xTimerDelete API, so that the pool index is freed when a timer is deleted
+      with MPU wrappers version 2.
+    + Fix the MPU wrapper macro mapping for the ARMv8-M ports.
+    + Fix silently failing critical sections in unprivileged tasks by
+      disallowing configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS with MPU wrappers
+      version 2 in the ARMv7-M MPU ports. The option now defaults to 0 under
+      version 2, and explicitly setting it to 1 raises a compile time error.
+      Behavior with MPU wrappers version 1 is unchanged.
+    + Fix a time of check to time of use race condition in vTaskListTasks, where
+      reading the volatile task count twice allowed a task to be created between
+      the reads, resulting in an undersized allocation and a possible buffer
+      overflow in uxTaskGetSystemState. We thank @srpatcha for their
+      contribution.
+    + Fix a spurious heap_5 assertion when configENABLE_HEAP_PROTECTOR is 1 and
+      an allocation cannot be satisfied. The free block search reaching the end
+      marker is a normal out of memory condition, so pvPortMalloc now returns
+      NULL and invokes the malloc failed hook instead of asserting.
+    + Fix batching stream buffers to unblock a receiver only after the buffered
+      byte count exceeds, rather than reaches, the trigger level. Previously a
+      receiver could be woken early and xStreamBufferReceive could return 0
+      bytes. Stream buffer and message buffer semantics are unchanged. We thank
+      @officialasishkumar for their contribution.
+    + Fix MISRA C 2012 Rule 20.4 violation by replacing `#define static` with a
+      STATIC macro, which also keeps the static variables in
+      vApplicationGetIdleTaskMemory and vApplicationGetPassiveIdleTaskMemory
+      static when portREMOVE_STATIC_QUALIFIER is defined. We thank @elsonwei for
+      their contribution.
+    + Fix undefined behavior in the MSVC-MingW port caused by left shifting a
+      signed int by 31 or more bits.
+    + Fix a duplicate Doxygen \defgroup identifier by giving
+      uxTaskBasePriorityGet its own group instead of reusing the
+      uxTaskPriorityGet group.
+    + Fix the incorrect #endif comment after vPortSetupTimerInterrupt in the GCC
+      and IAR RISC-V ports, which duplicated configMTIME_BASE_ADDRESS and
+      omitted configMTIMECMP_BASE_ADDRESS. We thank @cuiweixie for their
+      contribution.
+    + Fix incorrect #endif comments in croutine.c and queue.c, which reversed
+      the configUSE_CO_ROUTINES condition and named the wrong configuration
+      option for configSUPPORT_DYNAMIC_ALLOCATION. We thank @Zepp-Hanzj for
+      their contribution.
+    + Fix the configLIST_VOLATILE #endif comment and the documented parameter
+      names for uxListRemove in include/list.h. We thank @rakeshr-source for
+      their contribution.
+    + Fix the type and timeout values used in the xStreamBufferSend and
+      xMessageBufferSend documentation examples. We thank @Isla-jq for their
+      contribution.
+    + Fix copy and paste comment typos in xTaskGetApplicationTaskTag and
+      xTaskGetApplicationTaskTagFromISR, and a typo in the
+      xTaskGenericNotifyWait comment. We thank @wanghengZzz for their
+      contributions.
+    + Fix comment typos in the queue.h, list.h and task.h documentation,
+      including the xQueueReceiveFromISR and xQueueGenericSend examples, the
+      listGET_ITEM_VALUE_OF_HEAD_ENTRY \page tag, and the uxIndexToCLear typo.
+      We thank @zepp-chen for their contribution.
+    + Fix the FreeRTOSConfig.h template path referenced in README.md. We thank
+      @IClementI for their contribution.
+    + Fix the missing V prefix in the release_tag and namespace-prefix inputs of
+      the auto release workflow.
+    + Fix long path failures in the Windows kernel demo builds by enabling
+      Windows long path support in CI.
+    + Remove an unnecessary const variable from the GCC and IAR RISC-V ports. We
+      thank @IClementI for their contribution.
+
 Changes between FreeRTOS V11.2.0 and FreeRTOS V11.3.0 released March 2026
 
     + Correct minor mistakes in code comments in event_groups.c, include/queue.h,

examples/template_configuration/FreeRTOSConfig.h

@@ -577,7 +577,7 @@
 /* Defines the kernel provided implementation of
  * vApplicationGetIdleTaskMemory() and vApplicationGetTimerTaskMemory()
  * to provide the memory that is used by the Idle task and Timer task
- * respectively. The application can provide it's own implementation of
+ * respectively. The application can provide its own implementation of
  * vApplicationGetIdleTaskMemory() and vApplicationGetTimerTaskMemory() by
  * setting configKERNEL_PROVIDED_STATIC_MEMORY to 0 or leaving it undefined. */
 #define configKERNEL_PROVIDED_STATIC_MEMORY    1

include/FreeRTOS.h

@@ -1770,6 +1770,14 @@
     #define traceRETURN_vTaskDelete()
 #endif
 
+#ifndef traceENTER_xTaskPeriodicDelay
+    #define traceENTER_xTaskPeriodicDelay( pxPreviousWakeTime, xTimeIncrement )
+#endif
+
+#ifndef traceRETURN_xTaskPeriodicDelay
+    #define traceRETURN_xTaskPeriodicDelay( xIncrements )
+#endif
+
 #ifndef traceENTER_xTaskDelayUntil
     #define traceENTER_xTaskDelayUntil( pxPreviousWakeTime, xTimeIncrement )
 #endif

include/croutine.h

@@ -528,7 +528,7 @@ void vCoRoutineSchedule( void );
  * functions used by tasks.
  *
  * crQUEUE_SEND_FROM_ISR() and crQUEUE_RECEIVE_FROM_ISR() can only be used to
- * pass data between a co-routine and and ISR, whereas xQueueSendFromISR() and
+ * pass data between a co-routine and ISR, whereas xQueueSendFromISR() and
  * xQueueReceiveFromISR() can only be used to pass data between a task and and
  * ISR.
  *
@@ -628,7 +628,7 @@ void vCoRoutineSchedule( void );
  * functions used by tasks.
  *
  * crQUEUE_SEND_FROM_ISR() and crQUEUE_RECEIVE_FROM_ISR() can only be used to
- * pass data between a co-routine and and ISR, whereas xQueueSendFromISR() and
+ * pass data between a co-routine and ISR, whereas xQueueSendFromISR() and
  * xQueueReceiveFromISR() can only be used to pass data between a task and and
  * ISR.
  *

include/list.h

@@ -31,7 +31,7 @@
  * heavily for the schedulers needs, it is also available for use by
  * application code.
  *
- * list_ts can only store pointers to list_item_ts.  Each ListItem_t contains a
+ * List_t can only store pointers to ListItem_t.  Each ListItem_t contains a
  * numeric value (xItemValue).  Most of the time the lists are sorted in
  * ascending item value order.
  *
@@ -42,7 +42,7 @@
  * is because the tail contains a wrap back pointer to the true head of
  * the list.
  *
- * In addition to it's value, each list item contains a pointer to the next
+ * In addition to its value, each list item contains a pointer to the next
  * item in the list (pxNext), a pointer to the list it is in (pxContainer)
  * and a pointer back to the object that contains it.  These later two
  * pointers are included for efficiency of list manipulation.  There is
@@ -74,7 +74,7 @@
  * compiler's options were set for maximum optimisation has been inspected and
  * deemed to be as intended.  That said, as compiler technology advances, and
  * especially if aggressive cross module optimisation is used (a use case that
- * has not been exercised to any great extend) then it is feasible that the
+ * has not been exercised to any great extent) then it is feasible that the
  * volatile qualifier will be needed for correct optimisation.  It is expected
  * that a compiler removing essential code because, without the volatile
  * qualifier on the list structure members and with aggressive cross module
@@ -219,7 +219,7 @@ typedef struct xLIST
  * Access macro to retrieve the value of the list item at the head of a given
  * list.
  *
- * \page listGET_LIST_ITEM_VALUE listGET_LIST_ITEM_VALUE
+ * \page listGET_ITEM_VALUE_OF_HEAD_ENTRY listGET_ITEM_VALUE_OF_HEAD_ENTRY
  * \ingroup LinkedList
  */
 #define listGET_ITEM_VALUE_OF_HEAD_ENTRY( pxList )        ( ( ( pxList )->xListEnd ).pxNext->xItemValue )

include/mpu_wrappers.h

@@ -286,9 +286,17 @@
 
 #else /* portUSING_MPU_WRAPPERS */
 
-    #define PRIVILEGED_FUNCTION
-    #define PRIVILEGED_DATA
-    #define FREERTOS_SYSTEM_CALL
+    #ifndef PRIVILEGED_FUNCTION
+        #define PRIVILEGED_FUNCTION
+    #endif
+
+    #ifndef PRIVILEGED_DATA
+        #define PRIVILEGED_DATA
+    #endif
+
+    #ifndef FREERTOS_SYSTEM_CALL
+        #define FREERTOS_SYSTEM_CALL
+    #endif
 
 #endif /* portUSING_MPU_WRAPPERS */
 

include/queue.h

@@ -44,7 +44,7 @@
 
 /**
  * Type by which queues are referenced.  For example, a call to xQueueCreate()
- * returns an QueueHandle_t variable that can then be used as a parameter to
+ * returns a QueueHandle_t variable that can then be used as a parameter to
  * xQueueSend(), xQueueReceive(), etc.
  */
 struct QueueDefinition; /* Using old naming convention so as not to break kernel aware debuggers. */
@@ -60,7 +60,7 @@ typedef struct QueueDefinition   * QueueSetHandle_t;
 /**
  * Queue sets can contain both queues and semaphores, so the
  * QueueSetMemberHandle_t is defined as a type to be used where a parameter or
- * return value can be either an QueueHandle_t or an SemaphoreHandle_t.
+ * return value can be either a QueueHandle_t or a SemaphoreHandle_t.
  */
 typedef struct QueueDefinition   * QueueSetMemberHandle_t;
 
@@ -185,7 +185,7 @@ typedef struct QueueDefinition   * QueueSetMemberHandle_t;
  * @param pucQueueStorage If uxItemSize is not zero then
  * pucQueueStorage must point to a uint8_t array that is at least large
  * enough to hold the maximum number of items that can be in the queue at any
- * one time - which is ( uxQueueLength * uxItemsSize ) bytes.  If uxItemSize is
+ * one time - which is ( uxQueueLength * uxItemSize ) bytes.  If uxItemSize is
  * zero then pucQueueStorage can be NULL.
  *
  * @param pxQueueBuffer Must point to a variable of type StaticQueue_t, which
@@ -604,7 +604,7 @@ typedef struct QueueDefinition   * QueueSetMemberHandle_t;
  * BaseType_t xQueueGenericSend(
  *                                  QueueHandle_t xQueue,
  *                                  const void * pvItemToQueue,
- *                                  TickType_t xTicksToWait
+ *                                  TickType_t xTicksToWait,
  *                                  BaseType_t xCopyPosition
  *                              );
  * @endcode
@@ -1189,7 +1189,7 @@ void vQueueDelete( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
  *
  *  // ...
  *
- *  if( xHigherPrioritytaskWoken == pdTRUE )
+ *  if( xHigherPriorityTaskWoken == pdTRUE )
  *  {
  *      // Writing to the queue caused a task to unblock and the unblocked task
  *      // has a priority higher than or equal to the priority of the currently
@@ -1451,7 +1451,7 @@ BaseType_t xQueueGiveFromISR( QueueHandle_t xQueue,
  *      // task will be woken.
  *  }
  *
- *  if( xHigherPrioritytaskWoken == pdTRUE );
+ *  if( xHigherPriorityTaskWoken == pdTRUE )
  *  {
  *      // As xHigherPriorityTaskWoken is now set to pdTRUE then a context
  *      // switch should be requested. The macro used is port specific and
@@ -1664,7 +1664,7 @@ BaseType_t xQueueGiveMutexRecursive( QueueHandle_t xMutex ) PRIVILEGED_FUNCTION;
  * Note 2:  Blocking on a queue set that contains a mutex will not cause the
  * mutex holder to inherit the priority of the blocked task.
  *
- * Note 3:  An additional 4 bytes of RAM is required for each space in a every
+ * Note 3:  An additional 4 bytes of RAM is required for each space in every
  * queue added to a queue set.  Therefore counting semaphores that have a high
  * maximum count value should not be added to a queue set.
  *
@@ -1716,7 +1716,7 @@ BaseType_t xQueueGiveMutexRecursive( QueueHandle_t xMutex ) PRIVILEGED_FUNCTION;
  * Note 2:  Blocking on a queue set that contains a mutex will not cause the
  * mutex holder to inherit the priority of the blocked task.
  *
- * Note 3:  An additional 4 bytes of RAM is required for each space in a every
+ * Note 3:  An additional 4 bytes of RAM is required for each space in every
  * queue added to a queue set.  Therefore counting semaphores that have a high
  * maximum count value should not be added to a queue set.
  *
@@ -1767,7 +1767,7 @@ BaseType_t xQueueGiveMutexRecursive( QueueHandle_t xMutex ) PRIVILEGED_FUNCTION;
  * a call to xQueueSelectFromSet() has first returned a handle to that set member.
  *
  * @param xQueueOrSemaphore The handle of the queue or semaphore being added to
- * the queue set (cast to an QueueSetMemberHandle_t type).
+ * the queue set (cast to a QueueSetMemberHandle_t type).
  *
  * @param xQueueSet The handle of the queue set to which the queue or semaphore
  * is being added.
@@ -1790,7 +1790,7 @@ BaseType_t xQueueGiveMutexRecursive( QueueHandle_t xMutex ) PRIVILEGED_FUNCTION;
  * function.
  *
  * @param xQueueOrSemaphore The handle of the queue or semaphore being removed
- * from the queue set (cast to an QueueSetMemberHandle_t type).
+ * from the queue set (cast to a QueueSetMemberHandle_t type).
  *
  * @param xQueueSet The handle of the queue set in which the queue or semaphore
  * is included.
@@ -1836,7 +1836,7 @@ BaseType_t xQueueGiveMutexRecursive( QueueHandle_t xMutex ) PRIVILEGED_FUNCTION;
  * a QueueSetMemberHandle_t type) contained in the queue set that contains data,
  * or the handle of a semaphore (cast to a QueueSetMemberHandle_t type) contained
  * in the queue set that is available, or NULL if no such queue or semaphore
- * exists before before the specified block time expires.
+ * exists before the specified block time expires.
  */
 #if ( configUSE_QUEUE_SETS == 1 )
     QueueSetMemberHandle_t xQueueSelectFromSet( QueueSetHandle_t xQueueSet,

include/task.h

@@ -89,7 +89,7 @@
  * task. h
  *
  * Type by which tasks are referenced.  For example, a call to xTaskCreate
- * returns (via a pointer parameter) an TaskHandle_t variable that can then
+ * returns (via a pointer parameter) a TaskHandle_t variable that can then
  * be used as a parameter to vTaskDelete to delete the task.
  *
  * \defgroup TaskHandle_t TaskHandle_t
@@ -579,7 +579,7 @@ typedef enum
  *
  * Example usage:
  * @code{c}
- * // Create an TaskParameters_t structure that defines the task to be created.
+ * // Create a TaskParameters_t structure that defines the task to be created.
  * static const TaskParameters_t xCheckTaskParameters =
  * {
  *  vATask,     // pvTaskCode - the function that implements the task.
@@ -677,7 +677,7 @@ typedef enum
  *
  * Example usage:
  * @code{c}
- * // Create an TaskParameters_t structure that defines the task to be created.
+ * // Create a TaskParameters_t structure that defines the task to be created.
  * // The StaticTask_t variable is only included in the structure when
  * // configSUPPORT_STATIC_ALLOCATION is set to 1.  The PRIVILEGED_DATA macro can
  * // be used to force the variable into the RTOS kernel's privileged data area.
@@ -893,6 +893,43 @@ void vTaskDelete( TaskHandle_t xTaskToDelete ) PRIVILEGED_FUNCTION;
  */
 void vTaskDelay( const TickType_t xTicksToDelay ) PRIVILEGED_FUNCTION;
 
+/**
+ * task. h
+ * @code{c}
+ * TickType_t xTaskPeriodicDelay( TickType_t *pxPreviousWakeTime, const TickType_t xTimeIncrement );
+ * @endcode
+ *
+ * INCLUDE_xTaskDelayUntil must be defined as 1 for this function to be available.
+ * See the configuration section for more information.
+ *
+ * Periodic task delay to ensure a constant execution frequency.
+ *
+ * This function is similar to xTaskDelayUntil () with a few important differences:
+ * - pxPreviousWakeTime contains the last past wake time, so it never runs away
+ * - if you suspend the task, when you resume it pxPreviousWakeTime will instantly
+ *   catch up all skipped increments
+ * - it returns the number of increments added to pxPreviosWakeTime
+ *
+ * @param pxPreviousWakeTime Pointer to a variable that holds the time at which the
+ * task was last unblocked.  The variable must be initialised with the current time
+ * prior to its first use.  Following this the variable is automatically updated.
+ *
+ * @param xTimeIncrement The cycle time period.  The task will be unblocked at
+ * time *pxPreviousWakeTime + xTimeIncrement.  Passing the same xTimeIncrement
+ * parameter value will cause the task to execute with a fixed interval.
+ *
+ * @return Number of times xTimeIncrement has been added to pxPreviousWakeTime.
+ * It is 0 on the first call or if not enough ticks have been elapsed since the
+ * last call, 1 in normal circumstances or more than 1 if some period has been
+ * skipped for some reason (e.g. when the caller task is suspended for more than
+ * xTimeIncrement ticks).
+ *
+ * \defgroup xTaskPeriodicDelay xTaskPeriodicDelay
+ * \ingroup TaskCtrl
+ */
+TickType_t xTaskPeriodicDelay( TickType_t * const pxPreviousWakeTime,
+                               const TickType_t xTimeIncrement ) PRIVILEGED_FUNCTION;
+
 /**
  * task. h
  * @code{c}
@@ -1038,7 +1075,7 @@ BaseType_t xTaskDelayUntil( TickType_t * const pxPreviousWakeTime,
  *   // it itself.
  *   if( uxTaskPriorityGet( xHandle ) != tskIDLE_PRIORITY )
  *   {
- *       // The task has changed it's priority.
+ *       // The task has changed its priority.
  *   }
  *
  *   // ...
@@ -2120,7 +2157,7 @@ char * pcTaskGetName( TaskHandle_t xTaskToQuery ) PRIVILEGED_FUNCTION;
  * configUSE_TRACE_FACILITY must be defined as 1 in FreeRTOSConfig.h for
  * uxTaskGetSystemState() to be available.
  *
- * uxTaskGetSystemState() populates an TaskStatus_t structure for each task in
+ * uxTaskGetSystemState() populates a TaskStatus_t structure for each task in
  * the system.  TaskStatus_t structures contain, among other things, members
  * for the task handle, task name, task priority, task state, and total amount
  * of run time consumed by the task.  See the TaskStatus_t structure
@@ -3270,7 +3307,7 @@ uint32_t ulTaskGenericNotifyTake( UBaseType_t uxIndexToWaitOn,
 /**
  * task. h
  * @code{c}
- * BaseType_t xTaskNotifyStateClearIndexed( TaskHandle_t xTask, UBaseType_t uxIndexToCLear );
+ * BaseType_t xTaskNotifyStateClearIndexed( TaskHandle_t xTask, UBaseType_t uxIndexToClear );
  *
  * BaseType_t xTaskNotifyStateClear( TaskHandle_t xTask );
  * @endcode

portable/ARMv8M/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/ARMv8M/non_secure/portable/GCC/ARM_CM23/portasm.c

@@ -126,9 +126,9 @@
             " restore_general_regs_first_task:                \n"
             "    subs r2, #32                                 \n"
             "    ldmia r2!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r3!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r3!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r2!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r3!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r3!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r2, #48                                 \n"
             "    ldmia r2!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */
@@ -402,9 +402,9 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
             " restore_general_regs:                           \n"
             "    subs r2, #32                                 \n"
             "    ldmia r2!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r3!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r3!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r2!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r3!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r3!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r2, #48                                 \n"
             "    ldmia r2!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */

portable/ARMv8M/non_secure/portable/GCC/ARM_CM23_NTZ/portasm.c

@@ -121,9 +121,9 @@
             " restore_general_regs_first_task:                \n"
             "    subs r1, #32                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r1, #48                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */
@@ -375,9 +375,9 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
             " restore_general_regs:                           \n"
             "    subs r1, #32                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r1, #48                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */

portable/ARMv8M/secure/context/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/CodeWarrior/HCS12/port.c

@@ -63,7 +63,7 @@ scheduler startup function. */
 /* Calls to portENTER_CRITICAL() can be nested.  When they are nested the
 critical section should not be left (i.e. interrupts should not be re-enabled)
 until the nesting depth reaches 0.  This variable simply tracks the nesting
-depth.  Each task maintains it's own critical nesting depth variable so
+depth.  Each task maintains its own critical nesting depth variable so
 uxCriticalNesting is saved and restored from the task stack during a context
 switch. */
 volatile UBaseType_t uxCriticalNesting = 0xff;

portable/GCC/ARM_CM0/port.c

@@ -689,7 +689,7 @@ static void prvTaskExitError( void )
         }
 
         /* Shift the code by one before returning so it can be written directly
-         * into the the correct bit position of the attribute register. */
+         * into the correct bit position of the attribute register. */
         return( ulReturnValue << 1UL );
     }
 

portable/GCC/ARM_CM0/portasm.c

@@ -111,9 +111,9 @@
             " restore_general_regs_first_task:                \n"
             "    subs r1, #32                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r1, #48                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */
@@ -366,9 +366,9 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
             " restore_general_regs:                           \n"
             "    subs r1, #32                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r1, #48                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */

portable/GCC/ARM_CM23/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM23/non_secure/portasm.c

@@ -126,9 +126,9 @@
             " restore_general_regs_first_task:                \n"
             "    subs r2, #32                                 \n"
             "    ldmia r2!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r3!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r3!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r2!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r3!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r3!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r2, #48                                 \n"
             "    ldmia r2!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */
@@ -402,9 +402,9 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
             " restore_general_regs:                           \n"
             "    subs r2, #32                                 \n"
             "    ldmia r2!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r3!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r3!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r2!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r3!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r3!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r2, #48                                 \n"
             "    ldmia r2!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */

portable/GCC/ARM_CM23/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/GCC/ARM_CM23_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM23_NTZ/non_secure/portasm.c

@@ -121,9 +121,9 @@
             " restore_general_regs_first_task:                \n"
             "    subs r1, #32                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r1, #48                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */
@@ -375,9 +375,9 @@ void vClearInterruptMask( __attribute__( ( unused ) ) uint32_t ulMask ) /* __att
             " restore_general_regs:                           \n"
             "    subs r1, #32                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy half of the hardware saved context on the task stack. */
             "    ldmia r1!, {r4-r7}                           \n" /* r4-r7 contain rest half of the hardware saved context. */
-            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the the hardware saved context on the task stack. */
+            "    stmia r2!, {r4-r7}                           \n" /* Copy rest half of the hardware saved context on the task stack. */
             "    subs r1, #48                                 \n"
             "    ldmia r1!, {r4-r7}                           \n" /* Restore r8-r11. */
             "    mov r8, r4                                   \n" /* r8 = r4. */

portable/GCC/ARM_CM33/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM33/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/GCC/ARM_CM33_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM35P/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM35P/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/GCC/ARM_CM35P_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM3_MPU/port.c

@@ -96,12 +96,14 @@ typedef void ( * portISR_t )( void );
 #define portPERIPHERALS_START_ADDRESS             0x40000000UL
 #define portPERIPHERALS_END_ADDRESS               0x5FFFFFFFUL
 
-/* Constants required to access and manipulate the SysTick. */
+/* Constants required to access and manipulate the SysTick and other FreeRTOS
+ * interrupts. */
 #define portNVIC_SYSTICK_INT                      ( 0x00000002UL )
 #define portNVIC_SYSTICK_ENABLE                   ( 0x00000001UL )
 #define portMIN_INTERRUPT_PRIORITY                ( 255UL )
 #define portNVIC_PENDSV_PRI                       ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 16UL )
 #define portNVIC_SYSTICK_PRI                      ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 24UL )
+#define portNVIC_SVC_PRI                          ( ( ( uint32_t ) configMAX_SYSCALL_INTERRUPT_PRIORITY - 1UL ) << 24UL )
 
 /* Constants required to set up the initial stack. */
 #define portINITIAL_XPSR                          ( 0x01000000 )
@@ -877,12 +879,11 @@ BaseType_t xPortStartScheduler( void )
     }
     #endif /* configASSERT_DEFINED */
 
-    /* Make PendSV and SysTick the lowest priority interrupts, and make SVCall
-     * the highest priority. */
+    /* Make PendSV and SysTick the lowest priority interrupts, and configure
+     * SVCall for sufficient preemption priority. */
     portNVIC_SHPR3_REG |= portNVIC_PENDSV_PRI;
     portNVIC_SHPR3_REG |= portNVIC_SYSTICK_PRI;
-    portNVIC_SHPR2_REG = 0;
-
+    portNVIC_SHPR2_REG = portNVIC_SVC_PRI;
 
     /* Configure the regions in the MPU that are common to all tasks. */
     prvSetupMPU();
@@ -1206,7 +1207,7 @@ static uint32_t prvGetMPURegionSizeSetting( uint32_t ulActualSizeInBytes )
     }
 
     /* Shift the code by one before returning so it can be written directly
-     * into the the correct bit position of the attribute register. */
+     * into the correct bit position of the attribute register. */
     return( ulReturnValue << 1UL );
 }
 /*-----------------------------------------------------------*/

portable/GCC/ARM_CM4_MPU/port.c

@@ -106,12 +106,14 @@ typedef void ( * portISR_t )( void );
 #define portPERIPHERALS_START_ADDRESS             0x40000000UL
 #define portPERIPHERALS_END_ADDRESS               0x5FFFFFFFUL
 
-/* Constants required to access and manipulate the SysTick. */
+/* Constants required to access and manipulate the SysTick and other FreeRTOS
+ * interrupts. */
 #define portNVIC_SYSTICK_INT                      ( 0x00000002UL )
 #define portNVIC_SYSTICK_ENABLE                   ( 0x00000001UL )
 #define portMIN_INTERRUPT_PRIORITY                ( 255UL )
 #define portNVIC_PENDSV_PRI                       ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 16UL )
 #define portNVIC_SYSTICK_PRI                      ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 24UL )
+#define portNVIC_SVC_PRI                          ( ( ( uint32_t ) configMAX_SYSCALL_INTERRUPT_PRIORITY - 1UL ) << 24UL )
 
 /* Constants required to manipulate the VFP. */
 #define portFPCCR                                 ( ( volatile uint32_t * ) 0xe000ef34UL ) /* Floating point context control register. */
@@ -965,11 +967,11 @@ BaseType_t xPortStartScheduler( void )
     }
     #endif /* configASSERT_DEFINED */
 
-    /* Make PendSV and SysTick the lowest priority interrupts, and make SVCall
-     * the highest priority. */
+    /* Make PendSV and SysTick the lowest priority interrupts, and configure
+     * SVCall for sufficient preemption priority. */
     portNVIC_SHPR3_REG |= portNVIC_PENDSV_PRI;
     portNVIC_SHPR3_REG |= portNVIC_SYSTICK_PRI;
-    portNVIC_SHPR2_REG = 0;
+    portNVIC_SHPR2_REG = portNVIC_SVC_PRI;
 
     /* Configure the regions in the MPU that are common to all tasks. */
     prvSetupMPU();
@@ -1350,7 +1352,7 @@ static uint32_t prvGetMPURegionSizeSetting( uint32_t ulActualSizeInBytes )
     }
 
     /* Shift the code by one before returning so it can be written directly
-     * into the the correct bit position of the attribute register. */
+     * into the correct bit position of the attribute register. */
     return( ulReturnValue << 1UL );
 }
 /*-----------------------------------------------------------*/

portable/GCC/ARM_CM52/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM52/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/GCC/ARM_CM52_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM55/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM55/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/GCC/ARM_CM55_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM85/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CM85/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/GCC/ARM_CM85_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_CRx_MPU/port.c

@@ -489,7 +489,7 @@ static uint32_t prvGetMPURegionSizeEncoding( uint32_t ulActualMPURegionSize )
     }
 
     /* Shift the code by one before returning so it can be written directly
-     * into the the correct bit position of the attribute register. */
+     * into the correct bit position of the attribute register. */
     return ulReturnValue << 1UL;
 }
 

portable/GCC/ARM_STAR_MC3/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/ARM_STAR_MC3/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/GCC/ARM_STAR_MC3_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/GCC/HCS12/port.c

@@ -64,7 +64,7 @@ BaseType_t ATTR_NEAR xStartSchedulerNear( void );
 /* Calls to portENTER_CRITICAL() can be nested.  When they are nested the
  * critical section should not be left (i.e. interrupts should not be re-enabled)
  * until the nesting depth reaches 0.  This variable simply tracks the nesting
- * depth.  Each task maintains it's own critical nesting depth variable so
+ * depth.  Each task maintains its own critical nesting depth variable so
  * uxCriticalNesting is saved and restored from the task stack during a context
  * switch. */
 volatile UBaseType_t uxCriticalNesting = 0x80; /* un-initialized */

portable/GCC/MicroBlaze/port.c

@@ -63,7 +63,7 @@
 #define portISR_STACK_FILL_VALUE     0x55555555
 
 /* Counts the nesting depth of calls to portENTER_CRITICAL().  Each task
- * maintains it's own count, so this variable is saved as part of the task
+ * maintains its own count, so this variable is saved as part of the task
  * context. */
 volatile UBaseType_t uxCriticalNesting = portINITIAL_NESTING_VALUE;
 
@@ -235,7 +235,7 @@ void vPortYield( void )
 
     /* Perform the context switch in a critical section to assure it is
      * not interrupted by the tick ISR.  It is not a problem to do this as
-     * each task maintains it's own interrupt status. */
+     * each task maintains its own interrupt status. */
     portENTER_CRITICAL();
 
     /* Jump directly to the yield function to ensure there is no

portable/GCC/MicroBlazeV8/portmacro.h

@@ -322,7 +322,7 @@ void vApplicationSetupTimerInterrupt( void );
 
 /*
  * This is an application defined callback function used to clear whichever
- * interrupt was installed by the the vApplicationSetupTimerInterrupt() callback
+ * interrupt was installed by the vApplicationSetupTimerInterrupt() callback
  * function - in this case the interrupt generated by the AXI timer.  It is
  * provided as an application callback because the kernel will run on lots of
  * different MicroBlaze and FPGA configurations - not all of which will have the

portable/GCC/MicroBlazeV9/portmacro.h

@@ -337,7 +337,7 @@ void vApplicationSetupTimerInterrupt( void );
 
 /*
  * This is an application defined callback function used to clear whichever
- * interrupt was installed by the the vApplicationSetupTimerInterrupt() callback
+ * interrupt was installed by the vApplicationSetupTimerInterrupt() callback
  * function - in this case the interrupt generated by the AXI timer.  It is
  * provided as an application callback because the kernel will run on lots of
  * different MicroBlaze and FPGA configurations - not all of which will have the

portable/GCC/RISC-V/chip_specific_extensions/Pulpino_Vega_RV32M1RM/freertos_risc_v_chip_specific_extensions.h

@@ -27,7 +27,7 @@
  */
 
 /*
- * The FreeRTOS kernel's RISC-V port is split between the the code that is
+ * The FreeRTOS kernel's RISC-V port is split between the code that is
  * common across all currently supported RISC-V chips (implementations of the
  * RISC-V ISA), and code that tailors the port to a specific RISC-V chip:
  *

portable/GCC/RISC-V/chip_specific_extensions/RISCV_MTIME_CLINT_no_extensions/freertos_risc_v_chip_specific_extensions.h

@@ -27,7 +27,7 @@
  */
 
 /*
- * The FreeRTOS kernel's RISC-V port is split between the the code that is
+ * The FreeRTOS kernel's RISC-V port is split between the code that is
  * common across all currently supported RISC-V chips (implementations of the
  * RISC-V ISA), and code that tailors the port to a specific RISC-V chip:
  *

portable/GCC/RISC-V/chip_specific_extensions/RISCV_no_extensions/freertos_risc_v_chip_specific_extensions.h

@@ -27,7 +27,7 @@
  */
 
 /*
- * The FreeRTOS kernel's RISC-V port is split between the the code that is
+ * The FreeRTOS kernel's RISC-V port is split between the code that is
  * common across all currently supported RISC-V chips (implementations of the
  * RISC-V ISA), and code that tailors the port to a specific RISC-V chip:
  *

portable/GCC/RISC-V/chip_specific_extensions/RV32I_CLINT_no_extensions/freertos_risc_v_chip_specific_extensions.h

@@ -27,7 +27,7 @@
  */
 
 /*
- * The FreeRTOS kernel's RISC-V port is split between the the code that is
+ * The FreeRTOS kernel's RISC-V port is split between the code that is
  * common across all currently supported RISC-V chips (implementations of the
  * RISC-V ISA), and code that tailors the port to a specific RISC-V chip:
  *

portable/IAR/ARM_CM23/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM23/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/IAR/ARM_CM23_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM33/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM33/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/IAR/ARM_CM33_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM35P/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM35P/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/IAR/ARM_CM35P_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM4F_MPU/port.c

@@ -120,9 +120,11 @@ typedef void ( * portISR_t )( void );
 #define portCORTEX_M7_r0p1_ID                     ( 0x410FC271UL )
 #define portCORTEX_M7_r0p0_ID                     ( 0x410FC270UL )
 
+/* Constants to manipulate FreeRTOS interrupt priorities. */
 #define portMIN_INTERRUPT_PRIORITY                ( 255UL )
 #define portNVIC_PENDSV_PRI                       ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 16UL )
 #define portNVIC_SYSTICK_PRI                      ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 24UL )
+#define portNVIC_SVC_PRI                          ( ( ( uint32_t ) configMAX_SYSCALL_INTERRUPT_PRIORITY - 1UL ) << 24UL )
 
 /* Constants used to check the installation of the FreeRTOS interrupt handlers. */
 #define portSCB_VTOR_REG                          ( *( ( portISR_t ** ) 0xE000ED08 ) )
@@ -862,11 +864,11 @@ BaseType_t xPortStartScheduler( void )
     }
     #endif /* configASSERT_DEFINED */
 
-    /* Make PendSV and SysTick the lowest priority interrupts, and make SVCall
-     * the highest priority. */
+    /* Make PendSV and SysTick the lowest priority interrupts, and configure
+     * SVCall for sufficient preemption priority. */
     portNVIC_SHPR3_REG |= portNVIC_PENDSV_PRI;
     portNVIC_SHPR3_REG |= portNVIC_SYSTICK_PRI;
-    portNVIC_SHPR2_REG = 0;
+    portNVIC_SHPR2_REG = portNVIC_SVC_PRI;
 
     /* Configure the regions in the MPU that are common to all tasks. */
     prvSetupMPU();
@@ -1139,7 +1141,7 @@ static uint32_t prvGetMPURegionSizeSetting( uint32_t ulActualSizeInBytes )
     }
 
     /* Shift the code by one before returning so it can be written directly
-     * into the the correct bit position of the attribute register. */
+     * into the correct bit position of the attribute register. */
     return( ulReturnValue << 1UL );
 }
 /*-----------------------------------------------------------*/

portable/IAR/ARM_CM52/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM52/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/IAR/ARM_CM52_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM55/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM55/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/IAR/ARM_CM55_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM85/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_CM85/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/IAR/ARM_CM85_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_STAR_MC3/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/ARM_STAR_MC3/secure/secure_context.c

@@ -214,8 +214,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_Init( void )
         if( ulSecureContextIndex < secureconfigMAX_SECURE_CONTEXTS )
         {
             /* Allocate the stack space if possible. */
-            if( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) )
+            if( ( ulSecureStackSize < securecontextSTACK_SEAL_SIZE ) ||
+                ( ulSecureStackSize > ( UINT32_MAX - securecontextSTACK_SEAL_SIZE ) ) )
             {
+                /* Reject stacks that are too small (the CONTROL word would be
+                 * written before the allocation, corrupting the secure heap)
+                 * and sizes that would overflow when the seal size is added. */
                 pucStackMemory = NULL;
             }
             else
@@ -286,9 +290,12 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
                                                               void * pvTaskHandle )
 {
     uint32_t ulIPSR, ulSecureContextIndex;
+    uint8_t * pucStackLimit;
 
-    /* Read the Interrupt Program Status Register (IPSR) value. */
+    /* Read the Interrupt Program Status Register (IPSR) and Process Stack Limit
+     * Register (PSPLIM) value. */
     secureportREAD_IPSR( ulIPSR );
+    secureportREAD_PSPLIM( pucStackLimit );
 
     /* Do nothing if the processor is running in the Thread Mode. IPSR is zero
      * when the processor is running in the Thread Mode. */
@@ -300,8 +307,14 @@ secureportNON_SECURE_CALLABLE void SecureContext_FreeContext( SecureContextHandl
             ulSecureContextIndex = xSecureContextHandle - 1UL;
 
             /* Ensure that the secure context being deleted is associated with
-             * the task. */
-            if( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle )
+             * the task and is NOT the currently-loaded context. Freeing a
+             * context whose stack is currently loaded in PSPLIM would leave the
+             * running task referencing freed secure memory (use-after-free).
+             * pvTaskHandle is supplied by the non-secure side and is untrusted,
+             * so it is used only as an additional ownership match, not as
+             * authority. */
+            if( ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) &&
+                ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit != pucStackLimit ) )
             {
                 /* Free the stack space. */
                 vPortFree( xSecureContexts[ ulSecureContextIndex ].pucStackLimit );
@@ -349,7 +362,7 @@ secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandl
 
         secureportREAD_PSPLIM( pucStackLimit );
 
-        /* Ensure that task's context is loaded and the task is saving it's own
+        /* Ensure that task's context is loaded and the task is saving its own
          * context. */
         if( ( xSecureContexts[ ulSecureContextIndex ].pucStackLimit == pucStackLimit ) &&
             ( xSecureContexts[ ulSecureContextIndex ].pvTaskHandle == pvTaskHandle ) )

portable/IAR/ARM_STAR_MC3_NTZ/non_secure/port.c

@@ -1109,7 +1109,6 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 {
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
         #if defined( __ARMCC_VERSION )
-
             /* Declaration when these variable are defined in code instead of being
              * exported from linker scripts. */
             extern uint32_t * __syscalls_flash_start__;
@@ -1121,6 +1120,19 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         #endif /* defined( __ARMCC_VERSION ) */
     #endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
 
+    #if ( configENABLE_MPU == 1 )
+        #if defined( __ARMCC_VERSION )
+            /* Declaration when these variable are defined in code instead of being
+             * exported from linker scripts. */
+            extern uint32_t * __privileged_functions_start__;
+            extern uint32_t * __privileged_functions_end__;
+        #else
+            /* Declaration when these variable are exported from linker scripts. */
+            extern uint32_t __privileged_functions_start__[];
+            extern uint32_t __privileged_functions_end__[];
+        #endif /* defined( __ARMCC_VERSION ) */
+    #endif /* configENABLE_MPU == 1 */
+
     uint32_t ulPC;
 
     #if ( configENABLE_TRUSTZONE == 1 )
@@ -1170,39 +1182,54 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             break;
 
         case portSVC_FREE_SECURE_CONTEXT:
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
+            {
+            #endif /* configENABLE_MPU */
+                /* R0 contains TCB being freed and R1 contains the secure
+                 * context handle to be freed. */
+                ulR0 = pulCallerStackAddress[ 0 ];
+                ulR1 = pulCallerStackAddress[ 1 ];
 
-            /* R0 contains TCB being freed and R1 contains the secure
-             * context handle to be freed. */
-            ulR0 = pulCallerStackAddress[ 0 ];
-            ulR1 = pulCallerStackAddress[ 1 ];
-
-            /* Free the secure context. */
-            SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+                /* Free the secure context. */
+                SecureContext_FreeContext( ( SecureContextHandle_t ) ulR1, ( void * ) ulR0 );
+            #if ( configENABLE_MPU == 1 )
+            }
+            #endif /* configENABLE_MPU */
             break;
     #endif /* configENABLE_TRUSTZONE */
 
         case portSVC_START_SCHEDULER:
-            #if ( configENABLE_TRUSTZONE == 1 )
+            #if ( configENABLE_MPU == 1 )
+            if( ( ulPC >= ( uint32_t ) __privileged_functions_start__ ) &&
+                ( ulPC <= ( uint32_t ) __privileged_functions_end__ ) )
             {
-                /* De-prioritize the non-secure exceptions so that the
-                 * non-secure pendSV runs at the lowest priority. */
-                SecureInit_DePrioritizeNSExceptions();
+            #endif /* configENABLE_MPU */
+                #if ( configENABLE_TRUSTZONE == 1 )
+                {
+                    /* De-prioritize the non-secure exceptions so that the
+                     * non-secure pendSV runs at the lowest priority. */
+                    SecureInit_DePrioritizeNSExceptions();
 
-                /* Initialize the secure context management system. */
-                SecureContext_Init();
+                    /* Initialize the secure context management system. */
+                    SecureContext_Init();
+                }
+                #endif /* configENABLE_TRUSTZONE */
+
+                #if ( configENABLE_FPU == 1 )
+                {
+                    /* Setup the Floating Point Unit (FPU). */
+                    prvSetupFPU();
+                }
+                #endif /* configENABLE_FPU */
+
+                /* Setup the context of the first task so that the first task starts
+                 * executing. */
+                vRestoreContextOfFirstTask();
+            #if ( configENABLE_MPU == 1 )
             }
-            #endif /* configENABLE_TRUSTZONE */
-
-            #if ( configENABLE_FPU == 1 )
-            {
-                /* Setup the Floating Point Unit (FPU). */
-                prvSetupFPU();
-            }
-            #endif /* configENABLE_FPU */
-
-            /* Setup the context of the first task so that the first task starts
-             * executing. */
-            vRestoreContextOfFirstTask();
+            #endif /* configENABLE_MPU */
             break;
 
     #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )

portable/IAR/RISC-V/chip_specific_extensions/RV32I_CLINT_no_extensions/freertos_risc_v_chip_specific_extensions.h

@@ -27,7 +27,7 @@
  */
 
 /*
- * The FreeRTOS kernel's RISC-V port is split between the the code that is
+ * The FreeRTOS kernel's RISC-V port is split between the code that is
  * common across all currently supported RISC-V chips (implementations of the
  * RISC-V ISA), and code that tailors the port to a specific RISC-V chip:
  *

portable/MPLAB/PIC32MEC14xx/ISR_Support.h

@@ -78,7 +78,7 @@
     la      k0, uxInterruptNesting
     lw      s6, (k0)
 
-    /* If the nesting count is 0 then swap to the the system stack, otherwise
+    /* If the nesting count is 0 then swap to the system stack, otherwise
     the system stack is already being used. */
     bne     s6, zero, 1f
     nop

portable/MPLAB/PIC32MX/ISR_Support.h

@@ -60,7 +60,7 @@
     la          k0, uxInterruptNesting
     lw          s6, (k0)
 
-    /* If the nesting count is 0 then swap to the the system stack, otherwise
+    /* If the nesting count is 0 then swap to the system stack, otherwise
     the system stack is already being used. */
     bne         s6, zero, 1f
     nop

portable/MPLAB/PIC32MZ/ISR_Support.h

@@ -174,7 +174,7 @@
     la          k0, uxInterruptNesting
     lw          s6, (k0)
 
-    /* If the nesting count is 0 then swap to the the system stack, otherwise
+    /* If the nesting count is 0 then swap to the system stack, otherwise
     the system stack is already being used. */
     bne         s6, zero, 1f
     nop

portable/RVDS/ARM_CM4_MPU/port.c

@@ -95,13 +95,15 @@ typedef void ( * portISR_t )( void );
 #define portPERIPHERALS_START_ADDRESS             0x40000000UL
 #define portPERIPHERALS_END_ADDRESS               0x5FFFFFFFUL
 
-/* Constants required to access and manipulate the SysTick. */
+/* Constants required to access and manipulate the SysTick and other FreeRTOS
+ * interrupts. */
 #define portNVIC_SYSTICK_CLK                      ( 0x00000004UL )
 #define portNVIC_SYSTICK_INT                      ( 0x00000002UL )
 #define portNVIC_SYSTICK_ENABLE                   ( 0x00000001UL )
 #define portMIN_INTERRUPT_PRIORITY                ( 255UL )
 #define portNVIC_PENDSV_PRI                       ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 16UL )
 #define portNVIC_SYSTICK_PRI                      ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 24UL )
+#define portNVIC_SVC_PRI                          ( ( ( uint32_t ) configMAX_SYSCALL_INTERRUPT_PRIORITY - 1UL ) << 24UL )
 
 /* Constants required to manipulate the VFP. */
 #define portFPCCR                                 ( ( volatile uint32_t * ) 0xe000ef34UL ) /* Floating point context control register. */
@@ -966,12 +968,11 @@ BaseType_t xPortStartScheduler( void )
     }
     #endif /* configASSERT_DEFINED */
 
-    /* Make PendSV and SysTick the same priority as the kernel, and the SVC
-     * handler highest priority so it can be used to exit a critical section
-     * (where lower priorities are masked). */
+    /* Make PendSV and SysTick the lowest priority interrupts, and configure
+     * SVCall for sufficient preemption priority. */
     portNVIC_SHPR3_REG |= portNVIC_PENDSV_PRI;
     portNVIC_SHPR3_REG |= portNVIC_SYSTICK_PRI;
-    portNVIC_SHPR2_REG = 0;
+    portNVIC_SHPR2_REG = portNVIC_SVC_PRI;
 
     /* Configure the regions in the MPU that are common to all tasks. */
     prvSetupMPU();
@@ -1351,7 +1352,7 @@ static uint32_t prvGetMPURegionSizeSetting( uint32_t ulActualSizeInBytes )
     }
 
     /* Shift the code by one before returning so it can be written directly
-     * into the the correct bit position of the attribute register. */
+     * into the correct bit position of the attribute register. */
     return( ulReturnValue << 1UL );
 }
 /*-----------------------------------------------------------*/

portable/ThirdParty/Partner-Supported-Ports

@@ -1 +1 @@
-Subproject commit abc22103e1e6634b33457d4127bff1ab62f27f90
+Subproject commit fccbbce9bd7e227ee211b01fdbbcf133dc3a474a

queue.c

@@ -3225,7 +3225,16 @@ BaseType_t xQueueIsQueueFullFromISR( const QueueHandle_t xQueue )
 
         taskENTER_CRITICAL();
         {
-            if( ( ( Queue_t * ) xQueueOrSemaphore )->pxQueueSetContainer != NULL )
+            if( ( ( Queue_t * ) xQueueSet )->uxItemSize != ( UBaseType_t ) sizeof( Queue_t * ) )
+            {
+                /* The object passed as the queue set is not a queue set. A queue
+                 * set always has an item size of sizeof( Queue_t * ). Reject any
+                 * other object to prevent a type confusion in which
+                 * prvNotifyQueueSetContainer() would later copy uxItemSize bytes
+                 * from a single pointer on the stack. */
+                xReturn = pdFAIL;
+            }
+            else if( ( ( Queue_t * ) xQueueOrSemaphore )->pxQueueSetContainer != NULL )
             {
                 /* Cannot add a queue/semaphore to more than one queue set. */
                 xReturn = pdFAIL;

stream_buffer.c

@@ -272,7 +272,7 @@ static BaseType_t prvBytesInBufferMeetTriggerLevel( const StreamBuffer_t * const
  * the length and data bytes are written in two separate chunks, and we don't want
  * the reader to see the buffer as having grown until after all data is copied over.
  * This function takes a custom xHead value to indicate where to write to (necessary
- * for chaining) and returns the the resulting xHead position.
+ * for chaining) and returns the resulting xHead position.
  * To mark the write as complete, manually set the buffer's xHead field with the
  * returned xHead from this function.
  */
@@ -314,7 +314,7 @@ static size_t prvWriteMessageToBuffer( StreamBuffer_t * const pxStreamBuffer,
  * the writer to see the buffer as having more free space until after all data is
  * copied over, especially if we have to abort the read due to insufficient receiving space.
  * This function takes a custom xTail value to indicate where to read from (necessary
- * for chaining) and returns the the resulting xTail position.
+ * for chaining) and returns the resulting xTail position.
  * To mark the read as complete, manually set the buffer's xTail field with the
  * returned xTail from this function.
  */

tasks.c

@@ -2362,6 +2362,55 @@ STATIC void prvInitialiseNewTask( TaskFunction_t pxTaskCode,
 
 #if ( INCLUDE_xTaskDelayUntil == 1 )
 
+    TickType_t xTaskPeriodicDelay( TickType_t * const pxPreviousWakeTime,
+                                   const TickType_t xTimeIncrement )
+    {
+        TickType_t xIncrements, xTicksIncrements, xTicksToWait;
+
+        traceENTER_xTaskPeriodicDelay( pxPreviousWakeTime, xTimeIncrement );
+
+        configASSERT( pxPreviousWakeTime );
+        configASSERT( ( xTimeIncrement > 0U ) );
+
+        vTaskSuspendAll();
+        {
+            /* As long as everything is the same type, this plays well with overflows */
+            const TickType_t xTicksElapsed = xTickCount - *pxPreviousWakeTime;
+
+            configASSERT( uxSchedulerSuspended == 1U );
+
+            /* Number of increments to catch up: it could be 0 if
+             * not enough ticks have elapsed, 1 in the common case or
+             * more than 1 if the task has not been resumed in time */
+            xIncrements = xTicksElapsed / xTimeIncrement;
+            xTicksIncrements = xIncrements * xTimeIncrement;
+
+            /* Update to the last wake time */
+            *pxPreviousWakeTime += xTicksIncrements;
+
+            /* Ticks to the next wake time */
+            xTicksToWait = xTimeIncrement - ( xTicksElapsed - xTicksIncrements );
+
+            prvAddCurrentTaskToDelayedList( xTicksToWait, pdFALSE );
+        }
+
+        /* Force a reschedule if xTaskResumeAll has not already done so, we may
+         * have put ourselves to sleep. */
+        if( xTaskResumeAll() == pdFALSE )
+        {
+            taskYIELD_WITHIN_API();
+        }
+        else
+        {
+            mtCOVERAGE_TEST_MARKER();
+        }
+
+        traceRETURN_xTaskPeriodicDelay( xIncrements );
+
+        return xIncrements;
+    }
+
+
     BaseType_t xTaskDelayUntil( TickType_t * const pxPreviousWakeTime,
                                 const TickType_t xTimeIncrement )
     {
@@ -7930,7 +7979,7 @@ TickType_t uxTaskResetEventItemValue( void )
                 *pulNotificationValue = pxCurrentTCB->ulNotifiedValue[ uxIndexToWaitOn ];
             }
 
-            /* If ucNotifyValue is set then either the task never entered the
+            /* If ucNotifyState is set then either the task never entered the
              * blocked state (because a notification was already pending) or the
              * task unblocked because of a notification.  Otherwise the task
              * unblocked because of a timeout. */
@@ -8800,7 +8849,7 @@ STATIC void prvAddCurrentTaskToDelayedList( TickType_t xTicksToWait,
  * This is the kernel provided implementation of vApplicationGetIdleTaskMemory()
  * to provide the memory that is used by the Idle task. It is used when
  * configKERNEL_PROVIDED_STATIC_MEMORY is set to 1. The application can provide
- * it's own implementation of vApplicationGetIdleTaskMemory by setting
+ * its own implementation of vApplicationGetIdleTaskMemory by setting
  * configKERNEL_PROVIDED_STATIC_MEMORY to 0 or leaving it undefined.
  */
     void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
@@ -8841,7 +8890,7 @@ STATIC void prvAddCurrentTaskToDelayedList( TickType_t xTicksToWait,
  * This is the kernel provided implementation of vApplicationGetTimerTaskMemory()
  * to provide the memory that is used by the Timer service task. It is used when
  * configKERNEL_PROVIDED_STATIC_MEMORY is set to 1. The application can provide
- * it's own implementation of vApplicationGetTimerTaskMemory by setting
+ * its own implementation of vApplicationGetTimerTaskMemory by setting
  * configKERNEL_PROVIDED_STATIC_MEMORY to 0 or leaving it undefined.
  */
     void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,

timers.c

@@ -467,9 +467,11 @@
             xMessage.u.xTimerParameters.xMessageValue = xOptionalValue;
             xMessage.u.xTimerParameters.pxTimer = xTimer;
 
-            configASSERT( xCommandID < tmrFIRST_FROM_ISR_COMMAND );
+            /* Enforce a lower bound as well as an upper bound so that only
+             * valid task-issued commands are accepted here. */
+            configASSERT( ( xCommandID >= tmrCOMMAND_START_DONT_TRACE ) && ( xCommandID < tmrFIRST_FROM_ISR_COMMAND ) );
 
-            if( xCommandID < tmrFIRST_FROM_ISR_COMMAND )
+            if( ( xCommandID >= tmrCOMMAND_START_DONT_TRACE ) && ( xCommandID < tmrFIRST_FROM_ISR_COMMAND ) )
             {
                 if( xTaskGetSchedulerState() == taskSCHEDULER_RUNNING )
                 {