From f072d8f9d7a1a41e1fe38990ab8a9d1606e2b0e5 Mon Sep 17 00:00:00 2001
From: Marcus Weiner <marcus.weiner@gmail.com>
Date: Sun, 10 Sep 2023 16:02:10 +0200
Subject: [PATCH] Check page table bounds

Signed-off-by: Marcus Weiner <marcus.weiner@gmail.com>
---
 riscv64/src/mem.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/riscv64/src/mem.rs b/riscv64/src/mem.rs
index 6431a0c..be3ac9b 100644
--- a/riscv64/src/mem.rs
+++ b/riscv64/src/mem.rs
@@ -86,6 +86,7 @@ impl PageTable {
     }
 
     pub fn dump_entry(&self, at: u16) -> PageTableEntry {
+        assert!(at < 512, "index out of range: page tables always have 512 entries");
         let addr = self.addr + (at as u64 * Self::ENTRY_SIZE);
         let val = unsafe { read_volatile(addr as *const u64) };
         val.into()