[PATCH 0/1] MR8046: win32u: Don't load the display drivers in service processes.

[Rémi Bernon]

In service processes, `get_desktop_window` only creates a fake window
owned by the first calling thread, with only a handle and no client-side
object.

Before 9d6455f91cb7a7d166d5c4708d528b43a63eb4d7 `get_window_thread` was
returning an error (called from `send_message` > `process_message`) in
that case, as client-side object is missing.

After the commit, we only check handle existence and we now return
success and then try to send/process the desktop window message, waiting
for explorer startup which never happens.

Fixes: 9d6455f91cb7a7d166d5c4708d528b43a63eb4d7

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/8046

[PATCH 0/1] MR8046: win32u: Don't load the display drivers in service processes. - approved

[Huw Davies (＠huw)]

This merge request was approved by Huw Davies.
-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/8046

[PATCH 1/1] win32u: Don't load the display drivers in service processes.

[Rémi Bernon]

From: Rémi Bernon <rbernon(a)codeweavers.com>

In service processes, `get_desktop_window` only creates a fake window
owned by the first calling thread, with only a handle and no client-side
object.

Before 9d6455f91cb7a7d166d5c4708d528b43a63eb4d7 `get_window_thread` was
returning an error (called from `send_message` > `process_message`) in
that case, as client-side object is missing.

After the commit, we only check handle existence and we now return
success and then try to send/process the desktop window message, waiting
for explorer startup which never happens.

Fixes: 9d6455f91cb7a7d166d5c4708d528b43a63eb4d7
---
 dlls/win32u/driver.c         |  2 +-
 dlls/win32u/win32u_private.h |  1 +
 dlls/win32u/winstation.c     | 18 ++++++++++--------
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/dlls/win32u/driver.c b/dlls/win32u/driver.c
index 180f1187593..5e32e714b24 100644
--- a/dlls/win32u/driver.c
+++ b/dlls/win32u/driver.c
@@ -1011,7 +1011,7 @@ static void load_display_driver(void)
     USEROBJECTFLAGS flags;
     HWINSTA winstation;
 
-    if (!load_desktop_driver( get_desktop_window() ) || user_driver == &lazy_load_driver)
+    if (is_service_process() || !load_desktop_driver( get_desktop_window() ) || user_driver == &lazy_load_driver)
     {
         winstation = NtUserGetProcessWindowStation();
         if (!NtUserGetObjectInformation( winstation, UOI_FLAGS, &flags, sizeof(flags), NULL )
diff --git a/dlls/win32u/win32u_private.h b/dlls/win32u/win32u_private.h
index a7bee5bd93a..2e3dbdd20fb 100644
--- a/dlls/win32u/win32u_private.h
+++ b/dlls/win32u/win32u_private.h
@@ -231,6 +231,7 @@ extern NTSTATUS get_shared_queue( struct object_lock *lock, const queue_shm_t **
 extern NTSTATUS get_shared_input( UINT tid, struct object_lock *lock, const input_shm_t **input_shm );
 
 extern BOOL is_virtual_desktop(void);
+extern BOOL is_service_process(void);
 
 /* window.c */
 struct tagWND;
diff --git a/dlls/win32u/winstation.c b/dlls/win32u/winstation.c
index 766043ce282..2311c7a7cf0 100644
--- a/dlls/win32u/winstation.c
+++ b/dlls/win32u/winstation.c
@@ -347,6 +347,15 @@ BOOL is_virtual_desktop(void)
     return ret;
 }
 
+BOOL is_service_process(void)
+{
+    static const WCHAR wine_service_station_name[] = {'_','_','w','i','n','e','s','e','r','v','i','c','e','_','w','i','n','s','t','a','t','i','o','n',0};
+    WCHAR name[MAX_PATH];
+
+    return NtUserGetObjectInformation( NtUserGetProcessWindowStation(), UOI_NAME, name, sizeof(name), NULL ) &&
+           !wcscmp( name, wine_service_station_name );
+}
+
 /***********************************************************************
  *           NtUserCreateWindowStation  (win32u.@)
  */
@@ -779,20 +788,13 @@ static inline TEB64 *NtCurrentTeb64(void) { return (TEB64 *)NtCurrentTeb()->GdiB
 
 HWND get_desktop_window(void)
 {
-    static const WCHAR wine_service_station_name[] =
-        {'_','_','w','i','n','e','s','e','r','v','i','c','e','_','w','i','n','s','t','a','t','i','o','n',0};
     struct ntuser_thread_info *thread_info = NtUserGetThreadInfo();
-    WCHAR name[MAX_PATH];
     BOOL is_service;
 
     if (thread_info->top_window) return UlongToHandle( thread_info->top_window );
 
     /* don't create an actual explorer desktop window for services */
-    if (NtUserGetObjectInformation( NtUserGetProcessWindowStation(), UOI_NAME, name, sizeof(name), NULL )
-        && !wcscmp( name, wine_service_station_name ))
-        is_service = TRUE;
-    else
-        is_service = FALSE;
+    is_service = is_service_process();
 
     SERVER_START_REQ( get_desktop_window )
     {
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/8046