Update coverity violation for SMP (#81)

* Update coverity violation for SMP ( code surrounded by configNUMBER_OF_CORES > 1 ).
* Single core and common code are still scanned by lint tool.

.github/lexicon.txt

@@ -317,6 +317,7 @@ coproc
 coprocessor
 coprocessors
 coreid
+coverity
 covfs
 cp
 cpacr

MISRA.md

@@ -0,0 +1,72 @@
+# MISRA Compliance
+
+FreeRTOS-Kernel conforms to [MISRA C:2012](https://www.misra.org.uk/misra-c)
+guidelines, with the deviations listed below. Compliance is checked with
+Coverity static analysis. Since the FreeRTOS kernel is designed for
+small-embedded devices, it needs to have a very small memory footprint and
+has to be efficient. To achieve that and to increase the performance, it
+deviates from some MISRA rules. The specific deviations, suppressed inline,
+are listed below.
+
+Additionally, [MISRA configuration](#misra-configuration) contains project
+wide deviations.
+
+### Suppressed with Coverity Comments
+To find the violation references in the source files run grep on the source code
+with ( Assuming rule 8.4 violation; with justification in point 1 ):
+```
+grep 'MISRA Ref 8.4.1' . -rI
+```
+
+#### Rule 8.4
+
+_Ref 8.4.1_
+
+- MISRA C:2012 Rule 8.4: A compatible declaration shall be visible when an
+        object or function with external linkage is defined.
+        This rule requires that a compatible declaration is made available
+        in a header file when an object with external linkage is defined.
+        pxCurrentTCB(s) is defined with external linkage but it is only
+        referenced from the assembly code in the port files. Therefore, adding
+        a declaration in header file is not useful as the assembly code will
+        still need to declare it separately.
+
+### MISRA configuration
+
+Copy below content to `misra.conf` to run Coverity on FreeRTOS-Kernel.
+
+```
+// MISRA C-2012 Rules
+{
+    version : "2.0",
+    standard : "c2012",
+    title: "Coverity MISRA Configuration",
+    deviations : [
+        // Disable the following rules.
+        {
+            deviation: "Directive 4.8",
+            reason: "HeapRegion_t and HeapStats_t are used only in heap files but declared in portable.h which is included in multiple source files. As a result, these definitions appear in multiple source files where they are not used."
+        },
+        {
+            deviation: "Directive 4.9",
+            reason: "FreeRTOS-Kernel is optimised to work on small micro-controllers. To achieve that, function-like macros are used."
+        },
+        {
+            deviation: "Rule 1.2",
+            reason: "The __attribute__ tags are used via macros which are defined in port files."
+        },
+        {
+            deviation: "Rule 3.1",
+            reason: "We post HTTP links in code comments which contain // inside comments blocks."
+        },
+        {
+            deviation: "Rule 8.7",
+            reason: "API functions are not used by the library outside of the files they are defined; however, they must be externally visible in order to be used by an application."
+        },
+        {
+            deviation: "Rule 11.5",
+            reason: "Allow casts from `void *`. List owner, pvOwner, is stored as `void *` and are cast to various types for use in functions."
+        }
+    ]
+}
+```

include/task.h

@@ -84,7 +84,8 @@
  * \ingroup Tasks
  */
 struct tskTaskControlBlock; /* The old naming convention is used to prevent breaking kernel aware debuggers. */
-typedef struct tskTaskControlBlock * TaskHandle_t;
+typedef struct tskTaskControlBlock         * TaskHandle_t;
+typedef const struct tskTaskControlBlock   * ConstTaskHandle_t;
 
 /*
  * Defines the prototype to which the application task hook function must
@@ -193,7 +194,7 @@ typedef enum
  *
  * \ingroup TaskUtils
  */
-#define tskNO_AFFINITY      ( ( UBaseType_t ) -1U )
+#define tskNO_AFFINITY      ( ( UBaseType_t ) -1 )
 
 /**
  * task. h
@@ -271,7 +272,7 @@ typedef enum
 #define taskSCHEDULER_RUNNING        ( ( BaseType_t ) 2 )
 
 /* Checks if core ID is valid. */
-#define taskVALID_CORE_ID( xCoreID )    ( ( BaseType_t ) ( ( 0 <= xCoreID ) && ( xCoreID < configNUMBER_OF_CORES ) ) )
+#define taskVALID_CORE_ID( xCoreID )    ( ( ( ( ( BaseType_t ) 0 <= ( xCoreID ) ) && ( ( xCoreID ) < ( BaseType_t ) configNUMBER_OF_CORES ) ) ) ? ( pdTRUE ) : ( pdFALSE ) )
 
 /*-----------------------------------------------------------
 * TASK CREATION API
@@ -746,7 +747,7 @@ typedef enum
  * \defgroup vTaskAllocateMPURegions vTaskAllocateMPURegions
  * \ingroup Tasks
  */
-void vTaskAllocateMPURegions( TaskHandle_t xTask,
+void vTaskAllocateMPURegions( TaskHandle_t xTaskToModify,
                               const MemoryRegion_t * const pxRegions ) PRIVILEGED_FUNCTION;
 
 /**
@@ -1363,7 +1364,7 @@ BaseType_t xTaskResumeFromISR( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;
  *     }
  * }
  */
-    UBaseType_t vTaskCoreAffinityGet( const TaskHandle_t xTask );
+    UBaseType_t vTaskCoreAffinityGet( ConstTaskHandle_t xTask );
 #endif
 
 #if ( configUSE_TASK_PREEMPTION_DISABLE == 1 )
@@ -3418,6 +3419,42 @@ void vTaskInternalSetTimeOutState( TimeOut_t * const pxTimeOut ) PRIVILEGED_FUNC
  */
 void vTaskYieldWithinAPI( void );
 
+/*
+ * This function is only intended for use when implementing a port of the scheduler
+ * and is only available when portCRITICAL_NESTING_IN_TCB is set to 1 or configNUMBER_OF_CORES
+ * is greater than 1. This function can be used in the implementation of portENTER_CRITICAL
+ * if port wants to maintain critical nesting count in TCB in single core FreeRTOS.
+ * It should be used in the implementation of portENTER_CRITICAL if port is running a
+ * multiple core FreeRTOS.
+ */
+void vTaskEnterCritical( void );
+
+/*
+ * This function is only intended for use when implementing a port of the scheduler
+ * and is only available when portCRITICAL_NESTING_IN_TCB is set to 1 or configNUMBER_OF_CORES
+ * is greater than 1. This function can be used in the implementation of portEXIT_CRITICAL
+ * if port wants to maintain critical nesting count in TCB in single core FreeRTOS.
+ * It should be used in the implementation of portEXIT_CRITICAL if port is running a
+ * multiple core FreeRTOS.
+ */
+void vTaskExitCritical( void );
+
+/*
+ * This function is only intended for use when implementing a port of the scheduler
+ * and is only available when configNUMBER_OF_CORES is greater than 1. This function
+ * should be used in the implementation of portENTER_CRITICAL_FROM_ISR if port is
+ * running a multiple core FreeRTOS.
+ */
+portBASE_TYPE vTaskEnterCriticalFromISR( void );
+
+/*
+ * This function is only intended for use when implementing a port of the scheduler
+ * and is only available when configNUMBER_OF_CORES is greater than 1. This function
+ * should be used in the implementation of portEXIT_CRITICAL_FROM_ISR if port is
+ * running a multiple core FreeRTOS.
+ */
+void vTaskExitCriticalFromISR( portBASE_TYPE xSavedInterruptStatus );
+
 /* *INDENT-OFF* */
 #ifdef __cplusplus
     }