xzre_code: add count_pointers

xzre_code/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_library(xzre_code
 	backdoor_entry.c
 	chacha_decrypt.c
+	count_pointers.c
 	elf_parse.c
 	elf_symbol_get_addr.c
 	get_lzma_allocator.c

xzre_code/count_pointers.c

@@ -0,0 +1,22 @@
+/**
+ * Copyright (C) 2024 Stefano Moioli <[email protected]>
+ **/
+#include "xzre.h"
+
+BOOL count_pointers(
+	void **ptrs,
+	u64 *count_out, 
+	libc_imports_t *funcs
+){
+	if(!ptrs) return FALSE;
+	if(!funcs) return FALSE;
+	if(!funcs->malloc_usable_size) return FALSE;
+	size_t blockSize = funcs->malloc_usable_size(ptrs);
+	if(blockSize - 8 > 127) return FALSE;
+	size_t nWords = blockSize >> 3;
+
+	size_t i;
+	for(i=0; i < nWords && ptrs[i]; ++i);
+	*count_out = i;
+	return TRUE;
+}