From 59022e581892dd393285db5e9c7ab3de9ff0899f Mon Sep 17 00:00:00 2001
From: Alexandre Julliard <julliard@winehq.org>
Date: Tue, 28 Oct 2003 21:57:24 +0000
Subject: [PATCH] Restored emulation of protected instructions in 32-bit code
 when running with a Win9x version.

---
 dlls/kernel/instr.c    |  2 ++
 dlls/kernel/wowthunk.c | 26 ++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/dlls/kernel/instr.c b/dlls/kernel/instr.c
index c67e18333f3..80496771aeb 100644
--- a/dlls/kernel/instr.c
+++ b/dlls/kernel/instr.c
@@ -688,6 +688,7 @@ DWORD INSTR_EmulateInstruction( EXCEPTION_RECORD *rec, CONTEXT86 *context )
             break;  /* Unable to emulate it */
 
         case 0xcd: /* int <XX> */
+            if (IS_SELECTOR_SYSTEM(context->SegCs)) break;  /* don't emulate it in 32-bit code */
             if (!Dosvm.EmulateInterruptPM && !DPMI_LoadDosSystem())
             {
                 ERR("could not initialize interrupt handling\n");
@@ -701,6 +702,7 @@ DWORD INSTR_EmulateInstruction( EXCEPTION_RECORD *rec, CONTEXT86 *context )
             break;  /* Unable to emulate it */
 
         case 0xcf: /* iret */
+            if (IS_SELECTOR_SYSTEM(context->SegCs)) break;  /* don't emulate it in 32-bit code */
             if (long_op)
             {
                 DWORD *stack = get_stack( context );
diff --git a/dlls/kernel/wowthunk.c b/dlls/kernel/wowthunk.c
index 93909a92733..a95e8f84b57 100644
--- a/dlls/kernel/wowthunk.c
+++ b/dlls/kernel/wowthunk.c
@@ -91,6 +91,7 @@ extern BYTE Call16_End;
 
 extern void RELAY16_InitDebugLists(void);
 
+static LONG CALLBACK vectored_handler( EXCEPTION_POINTERS *ptrs );
 static SEGPTR call16_ret_addr;  /* segptr to CallTo16_Ret routine */
 
 /***********************************************************************
@@ -114,6 +115,9 @@ BOOL WOWTHUNK_Init(void)
         MAKESEGPTR( codesel, (char*)CALL32_CBClientEx_Ret - (char*)Call16_Ret_Start );
 
     if (TRACE_ON(relay) || TRACE_ON(snoop)) RELAY16_InitDebugLists();
+
+    /* setup emulation of protected instructions from 32-bit code (only for Win9x versions) */
+    if (GetVersion() & 0x80000000) RtlAddVectoredExceptionHandler( TRUE, vectored_handler );
     return TRUE;
 }
 
@@ -233,6 +237,28 @@ static DWORD vm86_handler( EXCEPTION_RECORD *record, EXCEPTION_REGISTRATION_RECO
 }
 
 
+/***********************************************************************
+ *           vectored_handler
+ *
+ * Vectored exception handler used to emulate protected instructions
+ * from 32-bit code.
+ */
+static LONG CALLBACK vectored_handler( EXCEPTION_POINTERS *ptrs )
+{
+    EXCEPTION_RECORD *record = ptrs->ExceptionRecord;
+    CONTEXT *context = ptrs->ContextRecord;
+
+    if (IS_SELECTOR_SYSTEM(context->SegCs) &&
+        (record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
+         record->ExceptionCode == EXCEPTION_PRIV_INSTRUCTION))
+    {
+        if (INSTR_EmulateInstruction( record, context ) == ExceptionContinueExecution)
+            return EXCEPTION_CONTINUE_EXECUTION;
+    }
+    return EXCEPTION_CONTINUE_SEARCH;
+}
+
+
 #else  /* __i386__ */
 
 BOOL WOWTHUNK_Init(void)