From 29b495c6b90c872d0725c63420904385d2cb511c Mon Sep 17 00:00:00 2001
From: ClF3 <smh66ccff@outlook.com>
Date: Mon, 4 Nov 2024 20:56:00 +0800
Subject: [PATCH] part2 ver 0.4.0 avoid prefetch (maybe)

---
 Part2-FlushReload/attacker.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Part2-FlushReload/attacker.c b/Part2-FlushReload/attacker.c
index 80c4f35..86ddc14 100644
--- a/Part2-FlushReload/attacker.c
+++ b/Part2-FlushReload/attacker.c
@@ -17,6 +17,7 @@ int main() {
     int flag = -1;
     CYCLES time = -1;
     int offset = 0;
+    int new_offset = 0;
     // buf is shared between the attacker and the victim
     char *buf = allocate_shared_buffer();
 
@@ -26,7 +27,13 @@ int main() {
     }
     for(int i = 0; i < WAIT_TIME; i++);
     for(int i = 0; i < 10000; i++) {
-        offset = (AVAR * offset + CVAR) % 1024;
+        new_offset = (AVAR * offset + CVAR) % 1024;
+        if(offset == new_offset||offset-new_offset==1||offset-new_offset==-1) {
+            offset = (offset + 712) % 1024;
+        }
+        else {
+            offset = new_offset;
+        }
         time = measure_one_block_access_time((ADDR_PTR)buf + offset * 128);
         if(time < CACHE_HIT_THRESHOLD) {
             flag = offset;