diff --git a/lab5/antiasan.c b/lab5/antiasan.c
index 8a8936d..121531a 100644
--- a/lab5/antiasan.c
+++ b/lab5/antiasan.c
@@ -2,5 +2,14 @@
 
 void antiasan(unsigned long addr)
 {
+    extern char gS[];
+   
+    unsigned long gS_addr = (unsigned long)gS;
+    unsigned long shadow_addr = (gS_addr >> 3) + 0x7fff8000;
+    
+    unsigned char *shadow = (unsigned char *)shadow_addr;
 
+    for (int i = 0; i < 5; i++) {
+        shadow[i] = 0;  
+    }
 }