libweston: Make weston_seat release safe

Ensure the server can safely handle client requests for wl_seat resource
that have become inert due to weston_seat object release and subsequent
destruction.

The clean-up involves, among other things, unsetting the destroyed
weston_seat object from the user data of wl_seat resources, and handling
this NULL user data case where required.

The list of sites extracting and using weston_seat object from wl_seat
resources which were audited for this patch are:

Legend:
N/A = Not Applicable (not implemented by weston)
FIXED = Fixed in the commit
OK = Already works correctly

== keyboard_shortcuts_inhibit_unstable_v1 ==
[N/A] zwp_keyboard_shortcuts_inhibit_manager_v1.inhibit_shortcuts
== tablet_input_unstable_v{1,2} ==
[N/A] zwp_tablet_manager_v{1,2}.get_tablet_seat
== text_input_unstable_v1 ==
[FIXED] zwp_text_input_v1.activate
[FIXED] zwp_text_input_v1.deactivate
== wl_data_device ==
[FIXED] wl_data_device_manager.get_data_device
[OK] wl_data_device.start_drag
[FIXED] wl_data_device.set_selection
[OK] wl_data_device.release
== wl_shell ==
[FIXED] wl_shell_surface.move
[FIXED] wl_shell_surface.resize
[FIXED] wl_shell_surface.set_popup
== xdg_shell and xdg_shell_unstable_v6 ==
[FIXED] xdg_toplevel.show_window_menu
[FIXED] xdg_toplevel.move
[FIXED] xdg_toplevel.resize
[FIXED] xdg_popup.grab
== xdg_shell_unstable_v5 ==
[FIXED] xdg_shell.get_xdg_popup
[FIXED] xdg_surface.show_window_menu
[FIXED] xdg_surface.move
[FIXED] xdg_surface.resize

Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>

diff --git a/compositor/text-backend.c b/compositor/text-backend.c
index e6ee249..4d8c085 100644 (file)
--- a/compositor/text-backend.c
+++ b/compositor/text-backend.c
@@ -193,10 +193,14 @@ text_input_activate(struct wl_client *client,
 {
        struct text_input *text_input = wl_resource_get_user_data(resource);
        struct weston_seat *weston_seat = wl_resource_get_user_data(seat);
-       struct input_method *input_method = weston_seat->input_method;
+       struct input_method *input_method;
        struct weston_compositor *ec = text_input->ec;
        struct text_input *current;
 
+       if (!weston_seat)
+               return;
+
+       input_method = weston_seat->input_method;
        if (input_method->input == text_input)
                return;
 
@@ -237,7 +241,7 @@ text_input_deactivate(struct wl_client *client,
 {
        struct weston_seat *weston_seat = wl_resource_get_user_data(seat);
 
-       if (weston_seat->input_method->input)
+       if (weston_seat && weston_seat->input_method->input)
                deactivate_input_method(weston_seat->input_method);
 }
 

diff --git a/libweston-desktop/seat.c b/libweston-desktop/seat.c
index 382b9e4..ae1c5e9 100644 (file)
--- a/libweston-desktop/seat.c
+++ b/libweston-desktop/seat.c
@@ -242,6 +242,9 @@ weston_desktop_seat_from_seat(struct weston_seat *wseat)
        struct wl_listener *listener;
        struct weston_desktop_seat *seat;
 
+       if (wseat == NULL)
+               return NULL;
+
        listener = wl_signal_get(&wseat->destroy_signal,
                                 weston_desktop_seat_destroy);
        if (listener != NULL)
@@ -270,7 +273,7 @@ weston_desktop_seat_from_seat(struct weston_seat *wseat)
 struct weston_desktop_surface *
 weston_desktop_seat_popup_grab_get_topmost_surface(struct weston_desktop_seat *seat)
 {
-       if (wl_list_empty(&seat->popup_grab.surfaces))
+       if (seat == NULL || wl_list_empty(&seat->popup_grab.surfaces))
                return NULL;
 
        struct wl_list *grab_link = seat->popup_grab.surfaces.next;
@@ -282,11 +285,14 @@ bool
 weston_desktop_seat_popup_grab_start(struct weston_desktop_seat *seat,
                                     struct wl_client *client, uint32_t serial)
 {
-       assert(seat->popup_grab.client == NULL || seat->popup_grab.client == client);
-
-       struct weston_keyboard *keyboard = weston_seat_get_keyboard(seat->seat);
-       struct weston_pointer *pointer = weston_seat_get_pointer(seat->seat);
-       struct weston_touch *touch = weston_seat_get_touch(seat->seat);
+       assert(seat == NULL || seat->popup_grab.client == NULL ||
+              seat->popup_grab.client == client);
+
+       struct weston_seat *wseat = seat != NULL ? seat->seat : NULL;
+       /* weston_seat_get_* functions can properly handle a NULL wseat */
+       struct weston_keyboard *keyboard = weston_seat_get_keyboard(wseat);
+       struct weston_pointer *pointer = weston_seat_get_pointer(wseat);
+       struct weston_touch *touch = weston_seat_get_touch(wseat);
 
        if ((keyboard == NULL || keyboard->grab_serial != serial) &&
            (pointer == NULL || pointer->grab_serial != serial) &&

diff --git a/libweston-desktop/wl-shell.c b/libweston-desktop/wl-shell.c
index 66553f4..8467dfb 100644 (file)
--- a/libweston-desktop/wl-shell.c
+++ b/libweston-desktop/wl-shell.c
@@ -220,6 +220,9 @@ weston_desktop_wl_shell_surface_protocol_move(struct wl_client *wl_client,
        struct weston_desktop_wl_shell_surface *surface =
                weston_desktop_surface_get_implementation_data(dsurface);
 
+       if (seat == NULL)
+               return;
+
        weston_desktop_api_move(surface->desktop, dsurface, seat, serial);
 }
 
@@ -238,6 +241,9 @@ weston_desktop_wl_shell_surface_protocol_resize(struct wl_client *wl_client,
        enum weston_desktop_surface_edge surf_edges =
                (enum weston_desktop_surface_edge) edges;
 
+       if (seat == NULL)
+               return;
+
        weston_desktop_api_resize(surface->desktop, dsurface, seat, serial, surf_edges);
 }
 
@@ -328,7 +334,8 @@ weston_desktop_wl_shell_surface_protocol_set_popup(struct wl_client *wl_client,
        struct weston_desktop_wl_shell_surface *surface =
                weston_desktop_surface_get_implementation_data(dsurface);
 
-       if (seat == NULL) {
+       /* Check that if we have a valid wseat we also got a valid desktop seat */
+       if (wseat != NULL && seat == NULL) {
                wl_client_post_no_memory(wl_client);
                return;
        }

diff --git a/libweston-desktop/xdg-shell-v6.c b/libweston-desktop/xdg-shell-v6.c
index 4db3748..f9902ff 100644 (file)
--- a/libweston-desktop/xdg-shell-v6.c
+++ b/libweston-desktop/xdg-shell-v6.c
@@ -378,6 +378,9 @@ weston_desktop_xdg_toplevel_protocol_show_window_menu(struct wl_client *wl_clien
                return;
        }
 
+       if (seat == NULL)
+               return;
+
        weston_desktop_api_show_window_menu(toplevel->base.desktop,
                                            dsurface, seat, x, y);
 }
@@ -402,6 +405,9 @@ weston_desktop_xdg_toplevel_protocol_move(struct wl_client *wl_client,
                return;
        }
 
+       if (seat == NULL)
+               return;
+
        weston_desktop_api_move(toplevel->base.desktop, dsurface, seat, serial);
 }
 
@@ -428,6 +434,9 @@ weston_desktop_xdg_toplevel_protocol_resize(struct wl_client *wl_client,
                return;
        }
 
+       if (seat == NULL)
+               return;
+
        weston_desktop_api_resize(toplevel->base.desktop,
                                  dsurface, seat, serial, surf_edges);
 }
@@ -762,6 +771,12 @@ weston_desktop_xdg_popup_protocol_grab(struct wl_client *wl_client,
        bool parent_is_toplevel =
                popup->parent->role == WESTON_DESKTOP_XDG_SURFACE_ROLE_TOPLEVEL;
 
+       /* Check that if we have a valid wseat we also got a valid desktop seat */
+       if (wseat != NULL && seat == NULL) {
+               wl_client_post_no_memory(wl_client);
+               return;
+       }
+
        if (popup->committed) {
                wl_resource_post_error(popup->resource,
                                       ZXDG_POPUP_V6_ERROR_INVALID_GRAB,
@@ -769,6 +784,15 @@ weston_desktop_xdg_popup_protocol_grab(struct wl_client *wl_client,
                return;
        }
 
+       /* If seat is NULL then get_topmost_surface will return NULL. In
+        * combination with setting parent_is_toplevel to TRUE here we will
+        * avoid posting an error, and we will instead gracefully fail the
+        * grab and dismiss the surface.
+        * FIXME: this is a hack because currently we cannot check the topmost
+        * parent with a destroyed weston_seat */
+       if (seat == NULL)
+               parent_is_toplevel = true;
+
        topmost = weston_desktop_seat_popup_grab_get_topmost_surface(seat);
        if ((topmost == NULL && !parent_is_toplevel) ||
            (topmost != NULL && topmost != popup->parent->desktop_surface)) {

diff --git a/libweston/data-device.c b/libweston/data-device.c
index b4bb4b3..e3dbee3 100644 (file)
--- a/libweston/data-device.c
+++ b/libweston/data-device.c
@@ -1167,9 +1167,10 @@ data_device_set_selection(struct wl_client *client,
                          struct wl_resource *resource,
                          struct wl_resource *source_resource, uint32_t serial)
 {
+       struct weston_seat *seat = wl_resource_get_user_data(resource);
        struct weston_data_source *source;
 
-       if (!source_resource)
+       if (!seat || !source_resource)
                return;
 
        source = wl_resource_get_user_data(source_resource);
@@ -1182,8 +1183,7 @@ data_device_set_selection(struct wl_client *client,
        }
 
        /* FIXME: Store serial and check against incoming serial here. */
-       weston_seat_set_selection(wl_resource_get_user_data(resource),
-                                 source, serial);
+       weston_seat_set_selection(seat, source, serial);
 }
 static void
 data_device_release(struct wl_client *client, struct wl_resource *resource)
@@ -1296,8 +1296,13 @@ get_data_device(struct wl_client *client,
                return;
        }
 
-       wl_list_insert(&seat->drag_resource_list,
-                      wl_resource_get_link(resource));
+       if (seat) {
+               wl_list_insert(&seat->drag_resource_list,
+                              wl_resource_get_link(resource));
+       } else {
+               wl_list_init(wl_resource_get_link(resource));
+       }
+
        wl_resource_set_implementation(resource, &data_device_interface,
                                       seat, unbind_data_device);
 }

diff --git a/libweston/input.c b/libweston/input.c
index 647268a..da00254 100644 (file)
--- a/libweston/input.c
+++ b/libweston/input.c
@@ -2420,13 +2420,10 @@ seat_get_pointer(struct wl_client *client, struct wl_resource *resource,
         * This prevents a race between the compositor sending new
         * capabilities and the client trying to use the old ones.
         */
-       struct weston_pointer *pointer = seat->pointer_state;
+       struct weston_pointer *pointer = seat ? seat->pointer_state : NULL;
        struct wl_resource *cr;
        struct weston_pointer_client *pointer_client;
 
-       if (!pointer)
-               return;
-
         cr = wl_resource_create(client, &wl_pointer_interface,
                                wl_resource_get_version(resource), id);
        if (cr == NULL) {
@@ -2434,6 +2431,15 @@ seat_get_pointer(struct wl_client *client, struct wl_resource *resource,
                return;
        }
 
+       wl_list_init(wl_resource_get_link(cr));
+       wl_resource_set_implementation(cr, &pointer_interface, pointer,
+                                      unbind_pointer_client_resource);
+
+       /* If we don't have a pointer_state, the resource is inert, so there
+        * is nothing more to set up */
+       if (!pointer)
+               return;
+
        pointer_client = weston_pointer_ensure_pointer_client(pointer, client);
        if (!pointer_client) {
                wl_client_post_no_memory(client);
@@ -2442,8 +2448,6 @@ seat_get_pointer(struct wl_client *client, struct wl_resource *resource,
 
        wl_list_insert(&pointer_client->pointer_resources,
                       wl_resource_get_link(cr));
-       wl_resource_set_implementation(cr, &pointer_interface, pointer,
-                                      unbind_pointer_client_resource);
 
        if (pointer->focus && pointer->focus->surface->resource &&
            wl_resource_get_client(pointer->focus->surface->resource) == client) {
@@ -2507,12 +2511,9 @@ seat_get_keyboard(struct wl_client *client, struct wl_resource *resource,
         * This prevents a race between the compositor sending new
         * capabilities and the client trying to use the old ones.
         */
-       struct weston_keyboard *keyboard = seat->keyboard_state;
+       struct weston_keyboard *keyboard = seat ? seat->keyboard_state : NULL;
        struct wl_resource *cr;
 
-       if (!keyboard)
-               return;
-
         cr = wl_resource_create(client, &wl_keyboard_interface,
                                wl_resource_get_version(resource), id);
        if (cr == NULL) {
@@ -2520,12 +2521,19 @@ seat_get_keyboard(struct wl_client *client, struct wl_resource *resource,
                return;
        }
 
+       wl_list_init(wl_resource_get_link(cr));
+       wl_resource_set_implementation(cr, &keyboard_interface,
+                                      keyboard, unbind_resource);
+
+       /* If we don't have a keyboard_state, the resource is inert, so there
+        * is nothing more to set up */
+       if (!keyboard)
+               return;
+
        /* May be moved to focused list later by either
         * weston_keyboard_set_focus or directly if this client is already
         * focused */
        wl_list_insert(&keyboard->resource_list, wl_resource_get_link(cr));
-       wl_resource_set_implementation(cr, &keyboard_interface,
-                                      keyboard, unbind_resource);
 
        if (wl_resource_get_version(cr) >= WL_KEYBOARD_REPEAT_INFO_SINCE_VERSION) {
                wl_keyboard_send_repeat_info(cr,
@@ -2587,12 +2595,9 @@ seat_get_touch(struct wl_client *client, struct wl_resource *resource,
         * This prevents a race between the compositor sending new
         * capabilities and the client trying to use the old ones.
         */
-       struct weston_touch *touch = seat->touch_state;
+       struct weston_touch *touch = seat ? seat->touch_state : NULL;
        struct wl_resource *cr;
 
-       if (!touch)
-               return;
-
         cr = wl_resource_create(client, &wl_touch_interface,
                                wl_resource_get_version(resource), id);
        if (cr == NULL) {
@@ -2600,6 +2605,15 @@ seat_get_touch(struct wl_client *client, struct wl_resource *resource,
                return;
        }
 
+       wl_list_init(wl_resource_get_link(cr));
+       wl_resource_set_implementation(cr, &touch_interface,
+                                      touch, unbind_resource);
+
+       /* If we don't have a touch_state, the resource is inert, so there
+        * is nothing more to set up */
+       if (!touch)
+               return;
+
        if (touch->focus &&
            wl_resource_get_client(touch->focus->surface->resource) == client) {
                wl_list_insert(&touch->focus_resource_list,
@@ -2608,8 +2622,6 @@ seat_get_touch(struct wl_client *client, struct wl_resource *resource,
                wl_list_insert(&touch->resource_list,
                               wl_resource_get_link(cr));
        }
-       wl_resource_set_implementation(cr, &touch_interface,
-                                      touch, unbind_resource);
 }
 
 static void
@@ -3087,6 +3099,19 @@ weston_seat_init(struct weston_seat *seat, struct weston_compositor *ec,
 WL_EXPORT void
 weston_seat_release(struct weston_seat *seat)
 {
+       struct wl_resource *resource;
+
+       wl_resource_for_each(resource, &seat->base_resource_list) {
+               wl_resource_set_user_data(resource, NULL);
+       }
+
+       wl_resource_for_each(resource, &seat->drag_resource_list) {
+               wl_resource_set_user_data(resource, NULL);
+       }
+
+       wl_list_remove(&seat->base_resource_list);
+       wl_list_remove(&seat->drag_resource_list);
+
        wl_list_remove(&seat->link);
 
        if (seat->saved_kbd_focus)