add MEM_OVERFLOW_CHECK and combine code with MEMP_OVERFLOW_CHECK

This moves untouched memory check and defines from memp.c and memp_priv.h
to mem.c and mem_priv.h (which is new).

src/include/lwip/opt.h

@@ -318,6 +318,19 @@
 #define MEMP_SANITY_CHECK               0
 #endif
 
+/**
+ * MEM_OVERFLOW_CHECK: mem overflow protection reserves a configurable
+ * amount of bytes before and after each heap allocation chunk and fills
+ * it with a prominent default value.
+ *    MEM_OVERFLOW_CHECK == 0 no checking
+ *    MEM_OVERFLOW_CHECK == 1 checks each element when it is freed
+ *    MEM_OVERFLOW_CHECK >= 2 checks all heap elements every time
+ *      mem_malloc() or mem_free() is called (useful but slow!)
+ */
+#if !defined MEM_OVERFLOW_CHECK || defined __DOXYGEN__
+#define MEM_OVERFLOW_CHECK              0
+#endif
+
 /**
  * MEM_SANITY_CHECK==1: run a sanity check after each mem_free() to make
  * sure that the linked list of heap elements is not corrupted.

src/include/lwip/priv/mem_priv.h

@@ -0,0 +1,84 @@
+/**
+ * @file
+ * lwIP internal memory implementations (do not use in application code)
+ */
+
+/*
+ * Copyright (c) 2018 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * 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.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Simon Goldschmidt <goldsimon@gmx.de>
+ *
+ */
+
+#ifndef LWIP_HDR_MEM_PRIV_H
+#define LWIP_HDR_MEM_PRIV_H
+
+#include "lwip/opt.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "lwip/mem.h"
+
+#if MEM_OVERFLOW_CHECK || MEMP_OVERFLOW_CHECK
+/* if MEM_OVERFLOW_CHECK or MEMP_OVERFLOW_CHECK is turned on, we reserve some
+ * bytes at the beginning and at the end of each element, initialize them as
+ * 0xcd and check them later.
+ * If MEM(P)_OVERFLOW_CHECK is >= 2, on every call to mem(p)_malloc or mem(p)_free,
+ * every single element in each pool/heap is checked!
+ * This is VERY SLOW but also very helpful.
+ * MEM_SANITY_REGION_BEFORE and MEM_SANITY_REGION_AFTER can be overridden in
+ * lwipopts.h to change the amount reserved for checking. */
+#ifndef MEM_SANITY_REGION_BEFORE
+#define MEM_SANITY_REGION_BEFORE  16
+#endif /* MEM_SANITY_REGION_BEFORE*/
+#if MEM_SANITY_REGION_BEFORE > 0
+#define MEM_SANITY_REGION_BEFORE_ALIGNED    LWIP_MEM_ALIGN_SIZE(MEM_SANITY_REGION_BEFORE)
+#else
+#define MEM_SANITY_REGION_BEFORE_ALIGNED    0
+#endif /* MEM_SANITY_REGION_BEFORE*/
+#ifndef MEM_SANITY_REGION_AFTER
+#define MEM_SANITY_REGION_AFTER   16
+#endif /* MEM_SANITY_REGION_AFTER*/
+#if MEM_SANITY_REGION_AFTER > 0
+#define MEM_SANITY_REGION_AFTER_ALIGNED     LWIP_MEM_ALIGN_SIZE(MEM_SANITY_REGION_AFTER)
+#else
+#define MEM_SANITY_REGION_AFTER_ALIGNED     0
+#endif /* MEM_SANITY_REGION_AFTER*/
+
+void mem_overflow_init_raw(void *p, size_t size);
+void mem_overflow_check_raw(void *p, size_t size, const char *descr1, const char *descr2);
+
+#endif /* MEM_OVERFLOW_CHECK || MEMP_OVERFLOW_CHECK */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LWIP_HDR_MEMP_PRIV_H */

src/include/lwip/priv/memp_priv.h

@@ -45,36 +45,14 @@ extern "C" {
 #endif
 
 #include "lwip/mem.h"
+#include "lwip/priv/mem_priv.h"
 
 #if MEMP_OVERFLOW_CHECK
-/* if MEMP_OVERFLOW_CHECK is turned on, we reserve some bytes at the beginning
- * and at the end of each element, initialize them as 0xcd and check
- * them later. */
-/* If MEMP_OVERFLOW_CHECK is >= 2, on every call to memp_malloc or memp_free,
- * every single element in each pool is checked!
- * This is VERY SLOW but also very helpful. */
-/* MEMP_SANITY_REGION_BEFORE and MEMP_SANITY_REGION_AFTER can be overridden in
- * lwipopts.h to change the amount reserved for checking. */
-#ifndef MEMP_SANITY_REGION_BEFORE
-#define MEMP_SANITY_REGION_BEFORE  16
-#endif /* MEMP_SANITY_REGION_BEFORE*/
-#if MEMP_SANITY_REGION_BEFORE > 0
-#define MEMP_SANITY_REGION_BEFORE_ALIGNED    LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_BEFORE)
-#else
-#define MEMP_SANITY_REGION_BEFORE_ALIGNED    0
-#endif /* MEMP_SANITY_REGION_BEFORE*/
-#ifndef MEMP_SANITY_REGION_AFTER
-#define MEMP_SANITY_REGION_AFTER   16
-#endif /* MEMP_SANITY_REGION_AFTER*/
-#if MEMP_SANITY_REGION_AFTER > 0
-#define MEMP_SANITY_REGION_AFTER_ALIGNED     LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_AFTER)
-#else
-#define MEMP_SANITY_REGION_AFTER_ALIGNED     0
-#endif /* MEMP_SANITY_REGION_AFTER*/
+
 
 /* MEMP_SIZE: save space for struct memp and for sanity check */
-#define MEMP_SIZE          (LWIP_MEM_ALIGN_SIZE(sizeof(struct memp)) + MEMP_SANITY_REGION_BEFORE_ALIGNED)
-#define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x) + MEMP_SANITY_REGION_AFTER_ALIGNED)
+#define MEMP_SIZE          (LWIP_MEM_ALIGN_SIZE(sizeof(struct memp)) + MEM_SANITY_REGION_BEFORE_ALIGNED)
+#define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x) + MEM_SANITY_REGION_AFTER_ALIGNED)
 
 #else /* MEMP_OVERFLOW_CHECK */