Alexandre Julliard : winecrt0: Initialize the Unix call dispatcher on first use.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 455a3c1796d9a1bc9c049637c37b50fabc48488f
URL:    https://gitlab.winehq.org/wine/wine/-/commit/455a3c1796d9a1bc9c049637c37b50f...

Author: Alexandre Julliard <julliard(a)winehq.org>
Date:   Thu May 23 11:46:59 2024 +0200

winecrt0: Initialize the Unix call dispatcher on first use.

---

 dlls/winecrt0/unix_lib.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/dlls/winecrt0/unix_lib.c b/dlls/winecrt0/unix_lib.c
index 5b809b6949d..fd5087cbe48 100644
--- a/dlls/winecrt0/unix_lib.c
+++ b/dlls/winecrt0/unix_lib.c
@@ -43,18 +43,29 @@ static NTSTATUS WINAPI unix_call_fallback( unixlib_handle_t handle, unsigned int
     return STATUS_DLL_NOT_FOUND;
 }
 
+static inline void *get_dispatcher( const char *name )
+{
+    UNICODE_STRING ntdll_name = RTL_CONSTANT_STRING( L"ntdll.dll" );
+    HMODULE module;
+    void **dispatcher;
+
+    LdrGetDllHandle( NULL, 0, &ntdll_name, &module );
+    dispatcher = RtlFindExportedRoutineByName( module, "__wine_unix_call_dispatcher" );
+    return dispatcher ? *dispatcher : (void *)unix_call_fallback;
+}
+
+static NTSTATUS WINAPI unix_call_init( unixlib_handle_t handle, unsigned int code, void *args )
+{
+    InterlockedExchangePointer( (void **)&__wine_unix_call_dispatcher,
+                                get_dispatcher( "__wine_unix_call_dispatcher" ));
+    return __wine_unix_call_dispatcher( handle, code, args );
+}
+
 unixlib_handle_t __wine_unixlib_handle = 0;
-NTSTATUS (WINAPI *__wine_unix_call_dispatcher)( unixlib_handle_t, unsigned int, void * ) = unix_call_fallback;
+NTSTATUS (WINAPI *__wine_unix_call_dispatcher)( unixlib_handle_t, unsigned int, void * ) = unix_call_init;
 
 NTSTATUS WINAPI __wine_init_unix_call(void)
 {
-    NTSTATUS status;
-    HMODULE module = GetModuleHandleW( L"ntdll.dll" );
-    void **p__wine_unix_call_dispatcher = (void **)GetProcAddress( module, "__wine_unix_call_dispatcher" );
-
-    if (!p__wine_unix_call_dispatcher) return STATUS_DLL_NOT_FOUND;
-    status = NtQueryVirtualMemory( GetCurrentProcess(), image_base(), MemoryWineUnixFuncs,
-                                   &__wine_unixlib_handle, sizeof(__wine_unixlib_handle), NULL );
-    if (!status) __wine_unix_call_dispatcher = *p__wine_unix_call_dispatcher;
-    return status;
+    return NtQueryVirtualMemory( GetCurrentProcess(), image_base(), MemoryWineUnixFuncs,
+                                 &__wine_unixlib_handle, sizeof(__wine_unixlib_handle), NULL );
 }