From c849ef58c05e00e8523d6f2a9d8f0da6315e75d9 Mon Sep 17 00:00:00 2001
From: Gabe Black <gblack@eecs.umich.edu>
Date: Wed, 25 Feb 2009 10:18:58 -0800
Subject: [PATCH] X86: Actually check page protections.

---
 src/arch/x86/tlb.cc | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/arch/x86/tlb.cc b/src/arch/x86/tlb.cc
index 372c8b997..603d4e45f 100644
--- a/src/arch/x86/tlb.cc
+++ b/src/arch/x86/tlb.cc
@@ -649,6 +649,18 @@ TLB::translate(RequestPtr req, ThreadContext *tc,
 #endif
             }
             // Do paging protection checks.
+            bool inUser = (csAttr.dpl == 3 &&
+                    !(flags & (CPL0FlagBit << FlagShift)));
+            if (inUser && !entry->user ||
+                    write && !entry->writable) {
+                // The page must have been present to get into the TLB in
+                // the first place. We'll assume the reserved bits are
+                // fine even though we're not checking them.
+                return new PageFault(vaddr, true, write,
+                                     inUser, false, execute);
+            }
+
+
             DPRINTF(TLB, "Entry found with paddr %#x, "
                     "doing protection checks.\n", entry->paddr);
             Addr paddr = entry->paddr | (vaddr & (entry->size-1));
-- 
2.30.2