Added memory health checks.

include/nuttx/mm/mm.h

@@ -312,6 +312,12 @@ struct mallinfo_task kmm_mallinfo_task(pid_t pid);
 #  endif
 #endif
 
+/* Functions contained in mm_check.c ****************************************/
+
+#ifdef CONFIG_MM_HEALTH_CHECK
+void mm_check_init(void);
+#endif
+
 /* Functions contained in mm_memdump.c **************************************/
 
 void mm_memdump(FAR struct mm_heap_s *heap, pid_t pid);

mm/Kconfig

@@ -207,3 +207,34 @@ config MM_PANIC_ON_FAILURE
 	depends on DEBUG_MM
 
 source "mm/iob/Kconfig"
+
+config MM_HEALTH_CHECK
+	bool "Memory health checks"
+	default n
+	---help---
+		If enabled, a worker will be used to perform
+		various health checks on the system memories.
+
+		The checks include:
+		* Check all stacks for overflow.
+		* The the heap for any corruption.
+
+config MM_CHECK_PERIOD
+	int "Health check period"
+	default 1
+	depends on MM_HEALTH_CHECK
+	---help---
+		The time period that the health checks will
+		be executed. In seconds.
+
+config MM_STACK_USAGE_SAFE_PERCENT
+	int "Safe stack usage"
+	default 90
+	depends on MM_HEALTH_CHECK
+	---help---
+		The stack usage that is considered safe. In
+		percent.
+
+		If the stack usage goes beyond this percentage,
+		the memory checks will assume that an overflow
+		has occured.

mm/Makefile

@@ -30,6 +30,7 @@ include shm/Make.defs
 include iob/Make.defs
 include circbuf/Make.defs
 include kasan/Make.defs
+include mm_check/Make.defs
 
 BINDIR ?= bin
 

mm/mm_check/Make.defs

@@ -0,0 +1,30 @@
+############################################################################
+# mm/mm_check/Make.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.  The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+# Memory health checks.
+
+ifeq ($(CONFIG_MM_HEALTH_CHECK),y)
+CSRCS += mm_check.c
+
+# Add the health checks to the build.
+
+DEPPATH += --dep-path mm_check
+VPATH += :mm_check
+endif

mm/mm_check/mm_check.c

@@ -0,0 +1,94 @@
+/****************************************************************************
+ * mm/mm_check/mm_check.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/mm/mm.h>
+#include <nuttx/sched.h>
+#include <nuttx/irq.h>
+#include <nuttx/wqueue.h>
+#include <nuttx/arch.h>
+#include <nuttx/compiler.h>
+#include <nuttx/config.h>
+
+#include <time.h>
+#include <assert.h>
+#include <sys/types.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifndef CONFIG_SCHED_LPWORK
+#error "Low priority work queue is required for the memory health checks."
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+static struct work_s work_q;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static void mm_check_worker(FAR void * arg)
+{
+  UNUSED(arg);
+
+  int i;
+  FAR struct tcb_s *tcb;
+  irqstate_t flags;
+  extern FAR struct tcb_s **g_pidhash;
+  extern volatile int g_npidhash;
+
+  for (i = 0; i < g_npidhash; i++)
+    {
+      flags = enter_critical_section();
+
+      tcb = g_pidhash[i];
+
+      if (tcb && ((up_check_tcbstack(tcb) * 100 / tcb->adj_stack_size)
+          > CONFIG_MM_STACK_USAGE_SAFE_PERCENT))
+        {
+          PANIC();
+        }
+
+      leave_critical_section(flags);
+    }
+
+  kmm_checkcorruption();
+
+  work_queue(LPWORK, &work_q, mm_check_worker, NULL,
+             (CONFIG_MM_CHECK_PERIOD * CLOCKS_PER_SEC));
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+void mm_check_init()
+{
+  work_queue(LPWORK, &work_q, mm_check_worker, NULL,
+             (CONFIG_MM_CHECK_PERIOD * CLOCKS_PER_SEC));
+}

sched/init/nx_start.c

@@ -502,6 +502,12 @@ void nx_start(void)
   iob_initialize();
 #endif
 
+#ifdef CONFIG_MM_HEALTH_CHECK
+  /* Initialize the memory health checks. */
+
+  mm_check_init();
+#endif
+
   /* Initialize the logic that determine unique process IDs. */
 
   g_npidhash = 4;