Provide is_zend_ptr() function to check if a pointer lays in Zend MM heap.

Author: dstogov

Zend/zend_alloc.c

@@ -2376,6 +2376,40 @@ ZEND_API int is_zend_mm(void)
 #endif
 }
 
+ZEND_API int is_zend_ptr(const void *ptr)
+{
+#if ZEND_MM_CUSTOM
+	if (AG(mm_heap)->use_custom_heap) {
+		return 0;
+	}
+#endif
+
+	if (AG(mm_heap)->main_chunk) {
+		zend_mm_chunk *chunk = AG(mm_heap)->main_chunk;
+
+		do {
+			if (ptr >= (void*)chunk
+			 && ptr < (void*)((char*)chunk + ZEND_MM_CHUNK_SIZE)) {
+				return 1;
+			}
+			chunk = chunk->next;
+		} while (chunk != AG(mm_heap)->main_chunk);
+	}
+
+	if (AG(mm_heap)->huge_list) {
+		zend_mm_huge_list *block = AG(mm_heap)->huge_list;
+
+		do {
+			if (ptr >= (void*)block
+			 && ptr < (void*)((char*)block + block->size)) {
+				return 1;
+			}
+			block = block->next;
+		} while (block != AG(mm_heap)->huge_list);
+	}
+	return 0;
+}
+
 #if !ZEND_DEBUG && defined(HAVE_BUILTIN_CONSTANT_P)
 #undef _emalloc
 

Zend/zend_alloc.h

@@ -224,6 +224,7 @@ ZEND_API int zend_set_memory_limit(size_t memory_limit);
 ZEND_API void start_memory_manager(void);
 ZEND_API void shutdown_memory_manager(int silent, int full_shutdown);
 ZEND_API int is_zend_mm(void);
+ZEND_API int is_zend_ptr(const void *ptr);
 
 ZEND_API size_t zend_memory_usage(int real_usage);
 ZEND_API size_t zend_memory_peak_usage(int real_usage);