score: PR2179: Fix initially locked PCP mutexes

Elevate the priority of the creating task to the ceiling priority in
case a semaphore is created as initially locked.

cpukit/score/src/coremutex.c

@@ -64,9 +64,9 @@ CORE_mutex_Status _CORE_mutex_Initialize(
     the_mutex->holder_id  = _Thread_Executing->Object.id;
     if ( _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) ||
          _CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes ) ) {
+      Priority_Control ceiling = the_mutex->Attributes.priority_ceiling;
 
-      if ( _Thread_Executing->current_priority <
+      if ( _Thread_Executing->current_priority < ceiling )
-             the_mutex->Attributes.priority_ceiling )
        return CORE_MUTEX_STATUS_CEILING_VIOLATED;
 #ifdef __RTEMS_STRICT_ORDER_MUTEX__
        _Chain_Prepend_unprotected( &_Thread_Executing->lock_mutex,
@@ -75,6 +75,7 @@ CORE_mutex_Status _CORE_mutex_Initialize(
 #endif
 
       _Thread_Executing->resource_count++;
+      _Thread_Change_priority( _Thread_Executing, ceiling, false );
     }
   } else {
     the_mutex->nest_count = 0;

testsuites/sptests/sp65/init.c

@@ -24,6 +24,17 @@ rtems_task Task_1(
   rtems_task_argument arg
 );
 
+static void assert_priority(rtems_task_priority expected)
+{
+  rtems_status_code sc;
+  rtems_task_priority prio;
+
+  sc = rtems_task_set_priority(RTEMS_SELF, RTEMS_CURRENT_PRIORITY, &prio);
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+  rtems_test_assert(prio == expected);
+}
+
 rtems_task Init(
   rtems_task_argument ignored
 )
@@ -33,6 +44,30 @@ rtems_task Init(
 
   puts( "\n\n*** TEST " TEST_NAME " ***" );
 
+  /*
+   * Verify that an initially locked priority ceiling mutex elevates the
+   * priority of the creating task.
+   */
+
+  status = rtems_semaphore_create(
+    rtems_build_name( 's','e','m','1' ),
+    0,
+    RTEMS_BINARY_SEMAPHORE | RTEMS_PRIORITY | RTEMS_PRIORITY_CEILING,
+    1,
+    &Mutex_id
+  );
+  rtems_test_assert(status == RTEMS_SUCCESSFUL);
+
+  assert_priority(1);
+
+  status = rtems_semaphore_release(Mutex_id);
+  rtems_test_assert(status == RTEMS_SUCCESSFUL);
+
+  assert_priority(TASK_PRIORITY);
+
+  status = rtems_semaphore_delete(Mutex_id);
+  rtems_test_assert(status == RTEMS_SUCCESSFUL);
+
   /*
    *  Create binary semaphore (a.k.a. Mutex) with Priority Ceiling
    *  attribute.

testsuites/sptests/sp65/sp65.doc

@@ -26,3 +26,5 @@ concepts:
 + Verify the priority ceiling mutex getting released which results in a thread
   being unblocked and the unblocked thread's priority being elevated.
 
++ Verify that an initially locked priority ceiling mutex elevates the priority
+  of the creating task.