From ca52c79c51088ca4c724b34e54c3bb97a9a51c67 Mon Sep 17 00:00:00 2001 From: Marius Vlad Date: Wed, 1 Feb 2023 22:25:06 +0200 Subject: [PATCH] remoting-plugin: Check virtual outputs/remoting instance With commit aab722bb, "backend-drm: prepare virtual output API for heterogeneous outputs", we now call the virtual destroy function, but when shutting the compositor we no longer have a remoting instance available. When searching out for a remoting output verify if the remoting instance is still available before attempting to search for a remoting output. Addresses the following crash at shutdown: 0x00007fd430a1d347 in lookup_remoted_output (output=0x557163d5dad0) at ../remoting/remoting-plugin.c:515 0x00007fd430a1d746 in remoting_output_destroy (output=0x557163d5dad0) at ../remoting/remoting-plugin.c:635 0x00007fd439e11ab9 in drm_virtual_output_destroy (base=0x557163d5dad0) at ../libweston/backend-drm/drm-virtual.c:265 0x00007fd43a8635d0 in weston_compositor_shutdown (ec=0x557163239530) at ../libweston/compositor.c:8271 0x00007fd439e029d4 in drm_destroy (backend=0x557163240ae0) at ../libweston/backend-drm/drm.c:2713 0x00007fd43a863e07 in weston_compositor_destroy (compositor=0x557163239530) at ../libweston/compositor.c:8626 Includes a note to point up what should be done about by checking out https://gitlab.freedesktop.org/wayland/weston/-/issues/591. Fixes aab722bb "backend-drm: prepare virtual output API for heterogeneous outputs" Signed-off-by: Marius Vlad --- remoting/remoting-plugin.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/remoting/remoting-plugin.c b/remoting/remoting-plugin.c index aabcd597..4d4dea7e 100644 --- a/remoting/remoting-plugin.c +++ b/remoting/remoting-plugin.c @@ -512,6 +512,16 @@ lookup_remoted_output(struct weston_output *output) struct weston_remoting *remoting = weston_remoting_get(c); struct remoted_output *remoted_output; + /* XXX: This could happen on the compositor shutdown path with our + * destroy listener being removed, and remoting_output_destroy() being + * called as a virtual destructor. + * + * See https://gitlab.freedesktop.org/wayland/weston/-/issues/591 for + * an alternative to the shutdown sequence. + */ + if (!remoting) + return NULL; + wl_list_for_each(remoted_output, &remoting->output_list, link) { if (remoted_output->output == output) return remoted_output; @@ -636,6 +646,9 @@ remoting_output_destroy(struct weston_output *output) struct remoted_output *remoted_output = lookup_remoted_output(output); struct weston_mode *mode, *next; + if (!remoted_output) + return; + weston_head_release(remoted_output->head); wl_list_for_each_safe(mode, next, &output->mode_list, link) {