From 30feb90c1cba922a7dac38204900e29b4788b935 Mon Sep 17 00:00:00 2001
From: Gabe Black <gblack@eecs.umich.edu>
Date: Sun, 12 Oct 2008 20:33:37 -0700
Subject: X86: Add a check type for interrupt gates.

---
 src/arch/x86/isa/microasm.isa       | 2 +-
 src/arch/x86/isa/microops/regop.isa | 7 ++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

(limited to 'src/arch')

diff --git a/src/arch/x86/isa/microasm.isa b/src/arch/x86/isa/microasm.isa
index 75e1dc524..29ec6dc94 100644
--- a/src/arch/x86/isa/microasm.isa
+++ b/src/arch/x86/isa/microasm.isa
@@ -85,7 +85,7 @@ let {{
         assembler.symbols["%ss" % letter.lower()] = "SEGMENT_REG_%sS" % letter
 
     # Add in symbols for the various checks of segment selectors.
-    for check in ("NoCheck", "CSCheck", "CallGateCheck",
+    for check in ("NoCheck", "CSCheck", "CallGateCheck", "IntGateCheck",
                   "SSCheck", "IretCheck", "IntCSCheck"):
         assembler.symbols[check] = "Seg%s" % check
 
diff --git a/src/arch/x86/isa/microops/regop.isa b/src/arch/x86/isa/microops/regop.isa
index b7883b2e2..0d019729f 100644
--- a/src/arch/x86/isa/microops/regop.isa
+++ b/src/arch/x86/isa/microops/regop.isa
@@ -233,7 +233,7 @@ output header {{
             uint64_t &quotient, uint64_t &remainder);
 
     enum SegmentSelectorCheck {
-      SegNoCheck, SegCSCheck, SegCallGateCheck,
+      SegNoCheck, SegCSCheck, SegCallGateCheck, SegIntGateCheck,
       SegSSCheck, SegIretCheck, SegIntCSCheck
     };
 }};
@@ -1041,6 +1041,11 @@ let {{
                 panic("CS checks for far calls/jumps through call gates"
                         "not implemented.\\n");
                 break;
+              case SegIntGateCheck:
+                if (desc.dpl < m5reg.cpl) {
+                    return new GeneralProtection((uint16_t)selector);
+                }
+                break;
               case SegSSCheck:
                 if (selector.si || selector.ti) {
                     if (!desc.p) {
-- 
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