From: Tim Harris <tharris@microsoft.com>
Date: Mon, 7 Feb 2011 23:05:28 +0000 (-0800)
Subject: X86: Read the LDT/GDT at CPL0 when executing an iret.
X-Git-Tag: stable_2012_02_02~566
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5810ab121c39f041aa6728696bc19e2e963eef90;p=gem5.git

X86: Read the LDT/GDT at CPL0 when executing an iret.

During iret access LDT/GDT at CPL0 rather than after transition to user mode
(if I'm reading the Intel IA-64 architecture spec correctly, the contents of
the descriptor table are read before the CPL is updated).
---

diff --git a/src/arch/x86/isa/insts/general_purpose/control_transfer/interrupts_and_exceptions.py b/src/arch/x86/isa/insts/general_purpose/control_transfer/interrupts_and_exceptions.py
index f8bafa540..19a344008 100644
--- a/src/arch/x86/isa/insts/general_purpose/control_transfer/interrupts_and_exceptions.py
+++ b/src/arch/x86/isa/insts/general_purpose/control_transfer/interrupts_and_exceptions.py
@@ -102,10 +102,10 @@ protToVirtFallThrough:
     andi t6, t2, 0xF8, dataSize=8
     andi t0, t2, 0x4, flags=(EZF,), dataSize=2
     br label("globalCSDescriptor"), flags=(CEZF,)
-    ld t8, tsl, [1, t0, t6], dataSize=8
+    ld t8, tsl, [1, t0, t6], dataSize=8, atCPL0=True
     br label("processCSDescriptor")
 globalCSDescriptor:
-    ld t8, tsg, [1, t0, t6], dataSize=8
+    ld t8, tsg, [1, t0, t6], dataSize=8, atCPL0=True
 processCSDescriptor:
     chks t2, t6, dataSize=8
 
@@ -159,10 +159,10 @@ doPopStackStuff:
     andi t7, t9, 0xF8, dataSize=8
     andi t0, t9, 0x4, flags=(EZF,), dataSize=2
     br label("globalSSDescriptor"), flags=(CEZF,)
-    ld t7, tsl, [1, t0, t7], dataSize=8
+    ld t7, tsl, [1, t0, t7], dataSize=8, atCPL0=True
     br label("processSSDescriptor")
 globalSSDescriptor:
-    ld t7, tsg, [1, t0, t7], dataSize=8
+    ld t7, tsg, [1, t0, t7], dataSize=8, atCPL0=True
 processSSDescriptor:
     chks t9, t7, dataSize=8