Implement InterlockedCompareExchange using CAS

wrappers/CMakeLists.txt

@@ -2,29 +2,48 @@ cmake_minimum_required(VERSION 3.13)
 
 project(corkel32 C)
 
-set(CMAKE_BUILD_TYPE Release)
+add_compile_definitions(_WIN32_WINNT=0x0400)
 
-add_library(corkdebug OBJECT
+add_library(
+  corkdebug OBJECT
   debug.c
 )
-link_libraries(corkdebug)
+target_compile_definitions(corkdebug PRIVATE _CRT_SECURE_NO_WARNINGS=1)
+
+add_library(
+  detect486 OBJECT
+  detect486.c
+)
+
+include(CheckSymbolExists)
+check_symbol_exists(RtlUnwind Windows.h HAS_RTL_UNWIND)
 
 # KERNEL32 => CORKEL32
-add_library(corkel32 SHARED
+add_library(
+  corkel32 MODULE
   kernel32.c
   advapi32.c
   comdlg32.c
   corkel32.def
 )
+target_link_libraries(corkel32 PRIVATE corkdebug detect486)
+target_compile_definitions(corkel32 PRIVATE _CRT_SECURE_NO_WARNINGS=1)
 
 # NTDLL => CORNT
-add_library(cornt SHARED
+add_library(
+  cornt MODULE
   ntdll.c
   cornt.def
 )
+target_link_libraries(cornt PRIVATE corkdebug)
+if(HAS_RTL_UNWIND)
+  target_compile_definitions(cornt PRIVATE HAS_RTL_UNWIND=1)
+endif()
 
 # USER32 => CORUSR
-add_library(corusr SHARED
+add_library(
+  corusr MODULE
   user32.c
   corusr.def
 )
+target_link_libraries(corusr PRIVATE corkdebug)

wrappers/advapi32.c

@@ -1,4 +1,3 @@
-#define _WIN32_WINNT 0x0400
 #include <windows.h>
 
 #include "debug.h"

wrappers/comdlg32.c

@@ -1,4 +1,3 @@
-#define _WIN32_WINNT 0x0400
 #include <windows.h>
 
 #include "debug.h"

wrappers/detect486.c

@@ -0,0 +1,26 @@
+#include "detect486.h"
+
+__declspec(naked) int is_cpu_486_or_newer(void)
+{
+  __asm {
+    pushfd
+    pop eax
+    mov ebx, eax
+    xor eax, 40000h ; toggle the AC bit in EFLAGS (only available in 486 or newer)
+    push eax
+    popfd
+    pushfd
+    pop eax
+    cmp eax, ebx
+    jz is_386
+    push ebx
+    popfd
+    xor eax, eax
+    inc eax
+    ret
+
+  is_386:
+    xor eax, eax
+    ret
+  }
+}

wrappers/detect486.h

@@ -0,0 +1,6 @@
+#ifndef DETECT_486
+#define DETECT_486
+
+int is_cpu_486_or_newer(void);
+
+#endif // DETECT_486

wrappers/kernel32.c

@@ -1,9 +1,10 @@
-#define _WIN32_WINNT 0x0400
-
 #include <stdio.h>
 #include <windows.h>
 
 #include "debug.h"
+#include "detect486.h"
+
+static int has_cmpxchg = 0;
 
 DWORD WINAPI CORKEL32_GetLastError()
 {
@@ -153,18 +154,36 @@ BOOL WINAPI CORKEL32_DeviceIoControl(HANDLE hDevice, DWORD dwIoControlCode, LPVO
   return e;
 }
 
+static char const* InterlockedCompareExchange_name = "InterlockedCompareExchange";
+
 // Reimplemented
-LONG WINAPI CORKEL32_InterlockedCompareExchange(LONG *dest,  LONG xchg,  LONG compare)
+__declspec(naked) LONG WINAPI CORKEL32_InterlockedCompareExchange(LONG* dest, LONG exchange, LONG compare)
 {
-  LONG temp = *dest;
-
-  Trace(TRACE_FORCE_DONT_PRINT, "InterlockedCompareExchange");
-
-  if (compare == *dest) {
-    *dest = xchg;
+  __asm {
+    cmp has_cmpxchg, 0
+    jz ICE_is_386
+    mov edx, DWORD PTR [esp + 4] ; dest
+    mov ecx, DWORD PTR [esp + 8] ; exchange
+    mov eax, DWORD PTR [esp + 12] ; compare
+    lock cmpxchg DWORD PTR [edx], ecx
+    ret 12
+
+  ICE_is_386:
+    push InterlockedCompareExchange_name
+    push TRACE_FORCE_DONT_PRINT
+    call Trace
+    add esp, 8
+
+    mov edx, DWORD PTR [esp + 4] ; dest
+    mov eax, DWORD PTR [edx]
+    cmp eax, DWORD PTR [esp + 12] ; compare
+    jne ICE_exit
+    mov ecx, DWORD PTR [esp + 8] ; exchange
+    mov DWORD PTR [edx], ecx
+
+  ICE_exit:
+    ret 12
   }
-
-  return temp;
 }
 
 HANDLE WINAPI CORKEL32_CreateToolhelp32Snapshot(DWORD param_0, DWORD param_1)
@@ -303,3 +322,12 @@ BOOL WINAPI CORKEL32_InitializeCriticalSectionAndSpinCount(LPCRITICAL_SECTION cr
 
   return TRUE;
 }
+
+BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
+{
+  if (fdwReason == DLL_PROCESS_ATTACH) {
+    has_cmpxchg = is_cpu_486_or_newer();
+  }
+
+  return TRUE;
+}

wrappers/ntdll.c

@@ -1,16 +1,19 @@
-#define _WIN32_WINNT 0x0400
 #include <windows.h>
+#include <lm.h> // for NTSTATUS
 
 #include "debug.h"
 
-ULONG WINAPI CORNT_RtlNtStatusToDosError(NTSTATUS)
+ULONG WINAPI CORNT_RtlNtStatusToDosError(NTSTATUS param_0)
 {
   Trace(TRACE_UNIMPLEMENTED, "RtlNtStatusToDosError");
   // TODO: Stub
   return 0;
 }
 
+#ifndef HAS_RTL_UNWIND
 extern NTAPI RtlUnwind(void* param_0, void* param_1, struct _EXCEPTION_RECORD* param_2, void* param_3);
+#endif
+
 VOID NTAPI CORNT_RtlUnwind(void *p0,void *p1,struct _EXCEPTION_RECORD *p2, void *p3)
 {
   Trace(TRACE_PASSTHROUGH, "RtlUnwind");

wrappers/user32.c

@@ -1,4 +1,3 @@
-#define _WIN32_WINNT 0x0400
 #include <windows.h>
 
 #include "debug.h"