Reserve the global skip_alloc_t variable space correctly

chunk.c

@@ -102,13 +102,13 @@ unsigned long		_dmalloc_alloc_total = 0;
  * here.  Basically we cannot do a alloc for the structure and we'd
  * like it to be static storage so we allocate an array of them to
  * make sure we have enough forward pointers, when all we need is
- * SKIP_SLOT_SIZE(MAX_SKIP_LEVEL + 1) bytes.
+ * SKIP_SLOT_SIZE(MAX_SKIP_LEVEL - 1) bytes.
  */
-static	skip_alloc_t	skip_free_alloc[MAX_SKIP_LEVEL /* read note ^^ */];
+static	skip_alloc_t	skip_free_alloc[SKIP_SLOT_COUNT(MAX_SKIP_LEVEL - 1)];
 static	skip_alloc_t	*skip_free_list = skip_free_alloc;
 
 /* skip list of all of our allocated blocks sorted by address */
-static	skip_alloc_t	skip_address_alloc[MAX_SKIP_LEVEL /* read note ^^ */];
+static	skip_alloc_t	skip_address_alloc[SKIP_SLOT_COUNT(MAX_SKIP_LEVEL - 1)];
 static	skip_alloc_t	*skip_address_list = skip_address_alloc;
 
 /* update slots which we use to update the skip lists */

chunk_loc.h

@@ -130,6 +130,9 @@ typedef struct skip_alloc_st {
 #define SKIP_SLOT_SIZE(next_n)	\
 	(sizeof(skip_alloc_t) + sizeof(skip_alloc_t *) * (next_n))
 
+#define SKIP_SLOT_COUNT(next_n)	\
+	DIVUP(SKIP_SLOT_SIZE(next_n), sizeof(skip_alloc_t))
+
 /* entry block magic numbers */
 #define ENTRY_BLOCK_MAGIC1	0xEBEB1111	/* for the eb_magic1 field */
 #define ENTRY_BLOCK_MAGIC2	0xEBEB2222	/* for the eb_magic2 field */

dmalloc_loc.h

@@ -70,6 +70,9 @@
 #undef MIN
 #define MIN(a,b)	(((a) < (b)) ? (a) : (b))
 
+#undef DIVUP
+#define DIVUP(a,b)	(((a) + (b) - 1) / (b))
+
 /*
  * bitflag tools for Variable and a Flag
  */