stos: pool: Add pool allocation header + tag usage

Signed-off-by: Chloe M. <chloe@mensia.org>

paw/stos/head/ex/pool.h

@@ -32,6 +32,9 @@
 #define POOL_REAL_PAGESZ \
     (PAGESIZE - sizeof(MEMORY_PAGE))
 
+/* Used to prevent corruption */
+#define POOL_MAGIC 0xCA7F00D
+
 /*
  * Valid pool types
  *
@@ -41,6 +44,20 @@ typedef enum {
     POOL_NON_PAGED
 } POOL_TYPE;
 
+/*
+ * Represents the header that goes before each returned
+ * and allocated block.
+ *
+ * @Magic:      Magic numbers
+ * @MemoryTag:  Tag assigned at allocation
+ * @Length:     Length of memory allocation
+ */
+typedef struct PACKED {
+    ULONG Magic;
+    ULONG MemoryTag;
+    USIZE Length;
+} MEMORY_HEADER;
+
 /*
  * Page data structure used internally to link together page
  * lists