From ab4e693342727f8fab7749273d89462d8e6aff06 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 23 Oct 2019 16:49:52 +0200 Subject: [PATCH] drm/property: Enforce more lifetime rules Properties can't be attached after registering, userspace would get confused (no one bothers to reprobe really). - Add kerneldoc - Enforce this with some checks. This needs a somewhat ugly check since connectors can be added later on, but we still need to attach all properties before they go public. Note that we already enforce that properties themselves are created before the entire device is registered. Unfortunately this doesn't work for drivers which have a ->load callback, see commit e0f32f78e51b9989ee89f608fd0dd10e9c230652 (tag: drm-misc-next-fixes-2019-09-18) Author: Daniel Vetter Date: Tue Sep 17 14:09:35 2019 +0200 drm/kms: Duct-tape for mode object lifetime checks for the full story. v2: Fix the superflous newline (Jani) and add commit citation to explain why we need to check for dev->registered (Thierry). Cc: Jani Nikula Cc: Rajat Jain Reviewed-by: Thierry Reding Reviewed-by: Jani Nikula Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20191023144953.28190-1-daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_mode_object.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c index 6a23e36ed4fe..35c2719407a8 100644 --- a/drivers/gpu/drm/drm_mode_object.c +++ b/drivers/gpu/drm/drm_mode_object.c @@ -224,12 +224,26 @@ EXPORT_SYMBOL(drm_mode_object_get); * This attaches the given property to the modeset object with the given initial * value. Currently this function cannot fail since the properties are stored in * a statically sized array. + * + * Note that all properties must be attached before the object itself is + * registered and accessible from userspace. */ void drm_object_attach_property(struct drm_mode_object *obj, struct drm_property *property, uint64_t init_val) { int count = obj->properties->count; + struct drm_device *dev = property->dev; + + + if (obj->type == DRM_MODE_OBJECT_CONNECTOR) { + struct drm_connector *connector = obj_to_connector(obj); + + WARN_ON(!dev->driver->load && + connector->registration_state == DRM_CONNECTOR_REGISTERED); + } else { + WARN_ON(!dev->driver->load && dev->registered); + } if (count == DRM_OBJECT_MAX_PROPERTY) { WARN(1, "Failed to attach object property (type: 0x%x). Please " -- 2.20.1