From c67bf9931fc860020a0e153f2a8f06bb00096065 Mon Sep 17 00:00:00 2001
From: Juan Sebastian Hoyos Ayala <juhoyosa@microsoft.com>
Date: Thu, 10 Dec 2020 12:01:28 -0800
Subject: [PATCH] Add intepretation of MOV ESP, EBX to unwindLazyState

---
 src/coreclr/vm/i386/gmsx86.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/coreclr/vm/i386/gmsx86.cpp b/src/coreclr/vm/i386/gmsx86.cpp
index de27dca090e4fd..d1e265f6698351 100644
--- a/src/coreclr/vm/i386/gmsx86.cpp
+++ b/src/coreclr/vm/i386/gmsx86.cpp
@@ -827,6 +827,8 @@ void LazyMachState::unwindLazyState(LazyMachState* baseState,
             case 0x89:                          // MOV r/m, reg
                 if (ip[1] == 0xEC)              // MOV ESP, EBP
                     goto mov_esp_ebp;
+                if (ip[1] == 0xDC)              // MOV ESP, EBX
+                    goto mov_esp_ebx;
                 // FALL THROUGH
 
             case 0x18:                          // SBB r/m8, r8
@@ -932,6 +934,13 @@ void LazyMachState::unwindLazyState(LazyMachState* baseState,
                     break;
                 }
 
+                if (ip[1] == 0xE3) {           // MOV ESP, EBX
+                mov_esp_ebx:
+                    ESP = PTR_TADDR(lazyState->_ebx);
+                    ip += 2;
+                    break;
+                }
+
                 if ((ip[1] & 0xc7) == 0x4 && ip[2] == 0x24) // move reg, [esp]
                 {
                     if ( ip[1] == 0x1C ) {  // MOV EBX, [ESP]