cpukit: Prevent error with disabled stack checker

When the stack checker is not enabled, the stack checker reporting
function can still be called. This prevents that call from performing a
null memory access in trying to find the high water mark if the stack
checker was never initialized.

This also introduces a test to ensure this call does not cause a crash.

Closes #4588

cpukit/libmisc/stackchk/check.c

@@ -410,6 +410,11 @@ static bool Stack_check_Dump_stack_usage(
   void     *low;
   void     *high_water_mark;
 
+  /* This is likely to occur if the stack checker is not actually enabled */
+  if ( stack->area == NULL ) {
+    return false;
+  }
+
   low  = Stack_check_Usable_stack_start(stack);
   size = Stack_check_Usable_stack_size(stack);
 

spec/build/testsuites/libtests/grp.yml

@@ -247,6 +247,8 @@ links:
   uid: stackchk
 - role: build-dependency
   uid: stackchk01
+- role: build-dependency
+  uid: stackchk02
 - role: build-dependency
   uid: stat
 - role: build-dependency

spec/build/testsuites/libtests/stackchk02.yml

@@ -0,0 +1,19 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2022 On-Line Applications Research (OAR)
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes: []
+ldflags: []
+links: []
+source:
+- testsuites/libtests/stackchk02/init.c
+stlib: []
+target: testsuites/libtests/stackchk02.exe
+type: build
+use-after: []
+use-before: []

testsuites/libtests/stackchk02/init.c

@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup libtests
+ */
+
+/*
+ * Copyright (C) 2022 On-Line Applications Research Corporation (OAR)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#define CONFIGURE_INIT
+
+#include <tmacros.h>
+
+#define CONFIGURE_APPLICATION_NEEDS_SIMPLE_CONSOLE_DRIVER
+#define CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER
+
+#define TASK_STACK_SIZE (RTEMS_MINIMUM_STACK_SIZE*3)
+
+#define CONFIGURE_MAXIMUM_TASKS               1
+
+#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
+
+#include <rtems/confdefs.h>
+
+#include <rtems/stackchk.h>
+
+const char rtems_test_name[] = "STACKCHK02";
+
+rtems_task Init(
+  rtems_task_argument argument
+)
+{
+  TEST_BEGIN();
+
+  rtems_stack_checker_report_usage();
+
+  TEST_END();
+  rtems_test_exit( 0 );
+}

testsuites/libtests/stackchk02/stackchk02.doc

@@ -0,0 +1,16 @@
+#  COPYRIGHT (c) 2022.
+#  On-Line Applications Research Corporation (OAR).
+#  The license and distribution terms for this file may be
+#  found in the file LICENSE in this distribution or at
+#  http://www.rtems.org/license/LICENSE.
+#
+This file describes the directives and concepts tested by this test set.
+
+test set name: stackchk02
+
+directives:
+  + rtems_stack_checker_report_usage
+
+concepts:
+  + This task verifies that the stack checker will not perform bad
+    accesses when not properly enabled.

testsuites/libtests/stackchk02/stackchk02.scn

@@ -0,0 +1,7 @@
+*** TEST STACKCHK02 ***
+                             STACK USAGE BY THREAD
+ID         NAME                  LOW        HIGH       CURRENT     AVAIL   USED
+0x09010001 IDLE                  0x10104940 0x1010713f 0x10107140  10224 N/A
+0x0a010001 UI1                   0x10109950 0x1010c14f 0x1010c150  10224 N/A
+
+*** END OF TEST STACKCHK02 ***