score: Fix task stack initialization

Do not adjust the stack area begin address since this may confuse the
stack allocator and result in failed stack frees.

Account for the alignment overhead in the stack space size estimate.

Check that the stack size is in the expected interval.

7 files changed, 41 insertions, 16 deletions

diff --git a/cpukit/include/rtems/confdefs/wkspace.h b/cpukit/include/rtems/confdefs/wkspace.h
index 46bdee6da1..1db4f2d09d 100644
--- a/cpukit/include/rtems/confdefs/wkspace.h
+++ b/cpukit/include/rtems/confdefs/wkspace.h
@@ -10,7 +10,7 @@
  */
 
 /*
- * Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
+ * Copyright (C) 2020, 2021 embedded brains GmbH (http://www.embedded-brains.de)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -55,12 +55,27 @@
 #include <rtems/score/stack.h>
 #include <rtems/sysinit.h>
 
+#if CPU_STACK_ALIGNMENT > CPU_HEAP_ALIGNMENT
+  #define _CONFIGURE_TASK_STACK_ALLOC_SIZE( _stack_size ) \
+    ( RTEMS_ALIGN_UP( \
+        ( _stack_size ) + CONTEXT_FP_SIZE, \
+        CPU_STACK_ALIGNMENT \
+      ) + CPU_STACK_ALIGNMENT - CPU_HEAP_ALIGNMENT )
+#else
+  #define _CONFIGURE_TASK_STACK_ALLOC_SIZE( _stack_size ) \
+    RTEMS_ALIGN_UP( ( _stack_size ) + CONTEXT_FP_SIZE, CPU_STACK_ALIGNMENT )
+#endif
+
 #ifdef CONFIGURE_TASK_STACK_FROM_ALLOCATOR
   #define _Configure_From_stackspace( _stack_size ) \
-    CONFIGURE_TASK_STACK_FROM_ALLOCATOR( _stack_size + CONTEXT_FP_SIZE )
+    CONFIGURE_TASK_STACK_FROM_ALLOCATOR( \
+      _CONFIGURE_TASK_STACK_ALLOC_SIZE( _stack_size ) \
+    )
 #else
   #define _Configure_From_stackspace( _stack_size ) \
-    _Configure_From_workspace( _stack_size + CONTEXT_FP_SIZE )
+    _Configure_From_workspace( \
+      _CONFIGURE_TASK_STACK_ALLOC_SIZE( _stack_size ) \
+    )
 #endif
 
 #ifndef CONFIGURE_EXTRA_TASK_STACKS
diff --git a/cpukit/include/rtems/score/stackimpl.h b/cpukit/include/rtems/score/stackimpl.h
index c15206002c..c261f8bd4f 100644
--- a/cpukit/include/rtems/score/stackimpl.h
+++ b/cpukit/include/rtems/score/stackimpl.h
@@ -135,7 +135,7 @@ RTEMS_INLINE_ROUTINE size_t _Stack_Extend_size(
 )
 {
   size_t extra_size;
-  size_t alignment_overhead;
+  size_t allocator_overhead;
 
   extra_size = _TLS_Get_allocation_size();
 
@@ -153,18 +153,16 @@ RTEMS_INLINE_ROUTINE size_t _Stack_Extend_size(
    * can be allocated for the stack, we have to align it up to the next stack
    * boundary.
    */
-  alignment_overhead = CPU_STACK_ALIGNMENT - 1;
+  extra_size += CPU_STACK_ALIGNMENT - 1;
 
-#if CPU_STACK_ALIGNMENT > CPU_HEAP_ALIGNMENT
   /*
    * If the heap allocator does not meet the stack alignment requirement, then
    * we have to do the stack alignment manually in _Thread_Initialize() and
    * need to allocate extra space for this.
    */
-  alignment_overhead += CPU_STACK_ALIGNMENT - CPU_HEAP_ALIGNMENT;
-#endif
+  allocator_overhead = CPU_STACK_ALIGNMENT - CPU_HEAP_ALIGNMENT;
 
-  if ( stack_size > SIZE_MAX - extra_size - alignment_overhead ) {
+  if ( stack_size > SIZE_MAX - extra_size - allocator_overhead ) {
     /*
      * In case of an unsigned integer overflow, saturate at the maximum value.
      */
@@ -172,9 +170,9 @@ RTEMS_INLINE_ROUTINE size_t _Stack_Extend_size(
   }
 
   stack_size += extra_size;
-  stack_size = RTEMS_ALIGN_UP( stack_size, CPU_STACK_ALIGNMENT );
+  stack_size = RTEMS_ALIGN_DOWN( stack_size, CPU_STACK_ALIGNMENT );
 
-  return stack_size;
+  return stack_size + allocator_overhead;
 }
 
 /**
diff --git a/cpukit/score/src/threadinitialize.c b/cpukit/score/src/threadinitialize.c
index 18c98c6995..9c1b809c3a 100644
--- a/cpukit/score/src/threadinitialize.c
+++ b/cpukit/score/src/threadinitialize.c
@@ -132,7 +132,6 @@ static bool _Thread_Try_initialize(
   stack_begin = config->stack_area;
   stack_end = stack_begin + config->stack_size;
   stack_align = CPU_STACK_ALIGNMENT;
-  stack_begin = (char *) RTEMS_ALIGN_UP( (uintptr_t) stack_begin, stack_align );
   stack_end = (char *) RTEMS_ALIGN_DOWN( (uintptr_t) stack_end, stack_align );
 
   /* Allocate floating-point context in stack area */
diff --git a/testsuites/psxtests/psxclassic01/init.c b/testsuites/psxtests/psxclassic01/init.c
index 42ddf10bec..04a77b1c30 100644
--- a/testsuites/psxtests/psxclassic01/init.c
+++ b/testsuites/psxtests/psxclassic01/init.c
@@ -78,7 +78,11 @@ static rtems_task test_task(rtems_task_argument arg)
   sc = pthread_attr_getstack( &attr, &addr, &size );
   rtems_test_assert( sc == 0 );
   rtems_test_assert( addr != NULL );
-  rtems_test_assert( size == RTEMS_MINIMUM_STACK_SIZE );
+  rtems_test_assert( size >= RTEMS_MINIMUM_STACK_SIZE );
+  rtems_test_assert(
+    size <= RTEMS_MINIMUM_STACK_SIZE + CPU_STACK_ALIGNMENT -
+      CPU_HEAP_ALIGNMENT
+  );
 
   value = -1;
   sc = pthread_attr_getscope( &attr, &value );
diff --git a/testsuites/psxtests/psxconfig01/init.c b/testsuites/psxtests/psxconfig01/init.c
index 6d7a227793..96bd4d8b3d 100644
--- a/testsuites/psxtests/psxconfig01/init.c
+++ b/testsuites/psxtests/psxconfig01/init.c
@@ -480,7 +480,11 @@ static rtems_task Init(rtems_task_argument argument)
 
     eno = pthread_attr_getstacksize(&attr, &stack_size);
     rtems_test_assert(eno == 0);
-    rtems_test_assert(stack_size == CPU_STACK_MINIMUM_SIZE);
+    rtems_test_assert(stack_size >= CPU_STACK_MINIMUM_SIZE);
+    rtems_test_assert(
+      stack_size <= CPU_STACK_MINIMUM_SIZE + CPU_STACK_ALIGNMENT -
+        CPU_HEAP_ALIGNMENT
+    );
 
     eno = pthread_attr_destroy(&attr);
     rtems_test_assert(eno == 0);
diff --git a/testsuites/sptests/spconfig01/init.c b/testsuites/sptests/spconfig01/init.c
index 7b13d69122..2d1b5d4145 100644
--- a/testsuites/sptests/spconfig01/init.c
+++ b/testsuites/sptests/spconfig01/init.c
@@ -101,7 +101,11 @@ static void test_stack_config(void)
 
   eno = pthread_attr_getstacksize(&attr, &stack_size);
   rtems_test_assert(eno == 0);
-  rtems_test_assert(stack_size == 2 * CPU_STACK_MINIMUM_SIZE);
+  rtems_test_assert(stack_size >= 2 * CPU_STACK_MINIMUM_SIZE);
+  rtems_test_assert(
+    stack_size <= 2 * CPU_STACK_MINIMUM_SIZE + CPU_STACK_ALIGNMENT -
+      CPU_HEAP_ALIGNMENT
+  );
 
   eno = pthread_attr_destroy(&attr);
   rtems_test_assert(eno == 0);
diff --git a/testsuites/validation/ts-default.h b/testsuites/validation/ts-default.h
index e8e2334825..d519df09ff 100644
--- a/testsuites/validation/ts-default.h
+++ b/testsuites/validation/ts-default.h
@@ -48,7 +48,8 @@
 
 #define TASK_STORAGE_SIZE \
   RTEMS_TASK_STORAGE_SIZE( \
-    MAX_TLS_SIZE + RTEMS_MINIMUM_STACK_SIZE, \
+    MAX_TLS_SIZE + RTEMS_MINIMUM_STACK_SIZE + \
+      CPU_STACK_ALIGNMENT - CPU_HEAP_ALIGNMENT, \
     TASK_ATTRIBUTES \
   )