diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index 98764e740c07..c3cee11ed7d9 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -377,18 +377,21 @@ void xen_console_resume(void) #ifdef CONFIG_HVC_XEN_FRONTEND static void xencons_disconnect_backend(struct xencons_info *info) { - if (info->irq > 0) - unbind_from_irqhandler(info->irq, NULL); - info->irq = 0; + if (info->hvc != NULL) + hvc_remove(info->hvc); + info->hvc = NULL; + if (info->irq > 0) { + evtchn_put(info->evtchn); + info->irq = 0; + info->evtchn = 0; + } + /* evtchn_put() will also close it so this is only an error path */ if (info->evtchn > 0) xenbus_free_evtchn(info->xbdev, info->evtchn); info->evtchn = 0; if (info->gntref > 0) gnttab_free_grant_references(info->gntref); info->gntref = 0; - if (info->hvc != NULL) - hvc_remove(info->hvc); - info->hvc = NULL; } static void xencons_free(struct xencons_info *info) @@ -553,10 +556,23 @@ static void xencons_backend_changed(struct xenbus_device *dev, if (dev->state == XenbusStateClosed) break; fallthrough; /* Missed the backend's CLOSING state */ - case XenbusStateClosing: + case XenbusStateClosing: { + struct xencons_info *info = dev_get_drvdata(&dev->dev);; + + /* + * Don't tear down the evtchn and grant ref before the other + * end has disconnected, but do stop userspace from trying + * to use the device before we allow the backend to close. + */ + if (info->hvc) { + hvc_remove(info->hvc); + info->hvc = NULL; + } + xenbus_frontend_closed(dev); break; } + } } static const struct xenbus_device_id xencons_ids[] = { @@ -616,7 +632,7 @@ static int __init xen_hvc_init(void) list_del(&info->list); spin_unlock_irqrestore(&xencons_lock, flags); if (info->irq) - unbind_from_irqhandler(info->irq, NULL); + evtchn_put(info->evtchn); kfree(info); return r; }