From: Rémi Bernon rbernon@codeweavers.com
--- dlls/win32u/win32u_private.h | 7 ++++ dlls/win32u/window.c | 74 ++++++++++++++++++++++++++---------- dlls/win32u/winstation.c | 7 ---- 3 files changed, 60 insertions(+), 28 deletions(-)
diff --git a/dlls/win32u/win32u_private.h b/dlls/win32u/win32u_private.h index 19c666928a8..a7bee5bd93a 100644 --- a/dlls/win32u/win32u_private.h +++ b/dlls/win32u/win32u_private.h @@ -212,6 +212,13 @@ struct object_lock }; #define OBJECT_LOCK_INIT {0}
+#if defined(__i386__) || defined(__x86_64__) +/* this prevents compilers from incorrectly reordering non-volatile reads (e.g., memcpy) from shared memory */ +#define __SHARED_READ_FENCE do { __asm__ __volatile__( "" ::: "memory" ); } while (0) +#else +#define __SHARED_READ_FENCE __atomic_thread_fence( __ATOMIC_ACQUIRE ) +#endif + /* Get shared session object's data pointer, must be called in a loop while STATUS_PENDING * is returned, lock must be initialized with OBJECT_LOCK_INIT. * diff --git a/dlls/win32u/window.c b/dlls/win32u/window.c index 5143093b381..9611e855ff8 100644 --- a/dlls/win32u/window.c +++ b/dlls/win32u/window.c @@ -35,8 +35,9 @@ WINE_DEFAULT_DEBUG_CHANNEL(win);
#define USER_HANDLE_TO_INDEX(hwnd) ((LOWORD(hwnd) - FIRST_USER_HANDLE) >> 1) +#define USER_HANDLE_FROM_INDEX(index, generation) UlongToHandle( (index << 1) + FIRST_USER_HANDLE + (generation << 16) )
-static void *user_handles[MAX_USER_HANDLES]; +static void *client_objects[MAX_USER_HANDLES];
#define SWP_AGG_NOGEOMETRYCHANGE \ (SWP_NOSIZE | SWP_NOCLIENTSIZE | SWP_NOZORDER) @@ -72,7 +73,7 @@ HANDLE alloc_user_handle( struct user_object *ptr, unsigned short type ) assert( index < MAX_USER_HANDLES ); ptr->handle = handle; ptr->type = type; - InterlockedExchangePointer( &user_handles[index], ptr ); + InterlockedExchangePointer( &client_objects[index], ptr ); } return handle; } @@ -91,27 +92,57 @@ static BOOL is_valid_entry( HANDLE handle, unsigned short type ) return is_valid_entry_uniq( handle, type, ReadAcquire64( (LONG64 *)&entries[index].uniq ) ); }
+static BOOL read_acquire_user_entry( HANDLE handle, unsigned short type, const volatile struct user_entry *src, struct user_entry *dst ) +{ + UINT64 uniq = ReadAcquire64( (LONG64 *)&src->uniq ); + if (!is_valid_entry_uniq( handle, type, uniq )) return FALSE; + dst->offset = src->offset; + dst->tid = src->tid; + dst->pid = src->pid; + dst->padding = src->padding; + __SHARED_READ_FENCE; + dst->uniq = ReadNoFence64( &src->uniq ); + return dst->uniq == uniq; +} + +static BOOL get_user_entry( HANDLE handle, unsigned short type, struct user_entry *entry, HANDLE *full ) +{ + const volatile struct user_entry *entries = shared_session->user_entries; + WORD index = USER_HANDLE_TO_INDEX( handle ); + + if (index >= MAX_USER_HANDLES) return FALSE; + if (!read_acquire_user_entry( handle, type, entries + index, entry )) return FALSE; + *full = USER_HANDLE_FROM_INDEX( index, entry->generation ); + return TRUE; +} + +static BOOL get_user_entry_at( WORD index, unsigned short type, struct user_entry *entry, HANDLE *full ) +{ + const volatile struct user_entry *entries = shared_session->user_entries; + if (index >= MAX_USER_HANDLES) return FALSE; + if (!read_acquire_user_entry( 0, type, entries + index, entry )) return FALSE; + *full = USER_HANDLE_FROM_INDEX( index, entry->generation ); + return TRUE; +} + /*********************************************************************** * get_user_handle_ptr */ void *get_user_handle_ptr( HANDLE handle, unsigned short type ) { - struct user_object *ptr; WORD index = USER_HANDLE_TO_INDEX( handle ); + struct user_object *ptr = NULL; + struct user_entry entry;
if (index >= MAX_USER_HANDLES) return NULL;
user_lock(); - if ((ptr = user_handles[index])) - { - if (ptr->type == type && - ((UINT)(UINT_PTR)ptr->handle == (UINT)(UINT_PTR)handle || - !HIWORD(handle) || HIWORD(handle) == 0xffff)) - return ptr; - ptr = NULL; - } - else ptr = OBJ_OTHER_PROCESS; - user_unlock(); + + if (!get_user_entry( handle, type, &entry, &handle )) ptr = NULL; + else if (entry.pid != GetCurrentProcessId()) ptr = OBJ_OTHER_PROCESS; + else ptr = client_objects[index]; + + if (!ptr || ptr == OBJ_OTHER_PROCESS) user_unlock(); return ptr; }
@@ -122,16 +153,17 @@ void *get_user_handle_ptr( HANDLE handle, unsigned short type ) */ void *next_process_user_handle_ptr( HANDLE *handle, unsigned short type ) { - struct user_object *ptr; WORD index = *handle ? USER_HANDLE_TO_INDEX( *handle ) + 1 : 0; + struct user_entry entry; + UINT i;
- while (index < MAX_USER_HANDLES) + for (i = index; i < MAX_USER_HANDLES; i++) { - if (!(ptr = user_handles[index++])) continue; /* OBJ_OTHER_PROCESS */ - if (ptr->type != type) continue; - *handle = ptr->handle; - return ptr; + if (!get_user_entry_at( i, type, &entry, handle )) continue; + if (entry.pid != GetCurrentProcessId()) continue; + return client_objects[i]; } + return NULL; }
@@ -142,7 +174,7 @@ static void set_user_handle_ptr( HANDLE handle, struct user_object *ptr ) { WORD index = USER_HANDLE_TO_INDEX(handle); assert( index < MAX_USER_HANDLES ); - InterlockedExchangePointer( &user_handles[index], ptr ); + InterlockedExchangePointer( &client_objects[index], ptr ); }
/*********************************************************************** @@ -169,7 +201,7 @@ void *free_user_handle( HANDLE handle, unsigned short type ) req->type = type; req->handle = wine_server_user_handle( handle ); if (wine_server_call( req )) ptr = NULL; - else InterlockedCompareExchangePointer( &user_handles[index], NULL, ptr ); + else InterlockedCompareExchangePointer( &client_objects[index], NULL, ptr ); } SERVER_END_REQ; user_unlock(); diff --git a/dlls/win32u/winstation.c b/dlls/win32u/winstation.c index edef603308e..766043ce282 100644 --- a/dlls/win32u/winstation.c +++ b/dlls/win32u/winstation.c @@ -80,13 +80,6 @@ static struct session_thread_data *get_session_thread_data(void) return thread_info->session_data; }
-#if defined(__i386__) || defined(__x86_64__) -/* this prevents compilers from incorrectly reordering non-volatile reads (e.g., memcpy) from shared memory */ -#define __SHARED_READ_FENCE do { __asm__ __volatile__( "" ::: "memory" ); } while (0) -#else -#define __SHARED_READ_FENCE __atomic_thread_fence( __ATOMIC_ACQUIRE ) -#endif - static void shared_object_acquire_seqlock( const shared_object_t *object, UINT64 *seq ) { while ((*seq = ReadNoFence64( &object->seq )) & 1) YieldProcessor();