Update antiasan.c 0513

Author: funiris

lab5/antiasan.c

@@ -1,5 +1,16 @@
-// TODO:
-void antiasan(unsigned long addr)
-{
+//TODO
 
+void antiasan(unsigned long addr) {
+    // This offset value (0x7fff8000) is specific to AddressSanitizer (ASan) 
+    // and is used to map main memory addresses to corresponding shadow byte
+    // addresses in the shadow memory region
+    
+    // Calculate the shadow byte address
+    unsigned long shadow_byte_addr = (addr >> 3) + 0x7fff8000;
+
+    // Convert the address to a char pointer
+    char *shadow_byte = (char *)shadow_byte_addr;
+
+    // Set the shadow byte to 0
+    *shadow_byte = 0;
 }