drm: Rework device removal signal

By moving the remove signal right before where we assert that the assert signal
list is empty, we create a strict contract requiring the remove signals to remove
themselves. We ensure this is true by calling `backend_destroy()` upon removal,
making sure that we don't double free the device fd.

Signed-off-by: liupeng <liupeng01@kylinos.cn>
This commit is contained in:
liupeng 2026-05-08 20:47:19 +08:00
parent 36cd9344e1
commit 510cda868d
2 changed files with 14 additions and 7 deletions

View file

@ -227,14 +227,19 @@ static int handle_udev_event(int fd, uint32_t mask, void *data) {
}
}
} else if (strcmp(action, "remove") == 0) {
bool found = false;
struct wlr_device *dev;
wl_list_for_each(dev, &session->devices, link) {
if (dev->dev == devnum) {
wlr_log(WLR_DEBUG, "DRM device %s removed", sysname);
wl_signal_emit_mutable(&dev->events.remove, NULL);
found = true;
break;
}
}
if (found) {
wlr_log(WLR_DEBUG, "DRM device %s removed", sysname);
wlr_session_close_file(session, dev);
}
}
out:
@ -375,11 +380,10 @@ void wlr_session_close_file(struct wlr_session *session,
wlr_log_errno(WLR_ERROR, "Failed to close device %d", dev->device_id);
}
wl_signal_emit_mutable(&dev->events.remove, NULL);
assert(wl_list_empty(&dev->events.change.listener_list));
// TODO: assert that the "remove" listener list is empty as well. Listeners
// will typically call wlr_session_close_file() in response, and
// wl_signal_emit_mutable() installs two phantom listeners, so we'd count
// these two.
assert(wl_list_empty(&dev->events.remove.listener_list));
close(dev->fd);
wl_list_remove(&dev->link);