On Fri, Jun 28, 2019 at 7:24 PM Sean Paul <sean@xxxxxxxxxx> wrote: > > On Fri, Jun 14, 2019 at 08:17:23AM +0200, Daniel Vetter wrote: > > Only dynamic mode objects, i.e. those which are refcounted and have a free > > callback, can be added while the overall drm_device is visible to > > userspace. All others must be added before drm_dev_register and > > removed after drm_dev_unregister. > > > > Small issue around drivers still using the load/unload callbacks, we > > need to make sure we set dev->registered so that load/unload code in > > these callbacks doesn't trigger false warnings. Only a small > > adjustement in drm_dev_register was needed. > > > > Motivated by some irc discussions about object ids of dynamic objects > > like blobs become invalid, and me going on a bit an audit spree. > > > > Seems like a very worthwhile change, any idea how many drivers are going > to be sad after this change? None I think/hope, really just defense WARN_ON just in case. The main ones that would be sad are all the ones that have a ->load callback, but I'm taking care of them. Everyone else does things correctly and calls drm_dev_register last in their probe function (or around where they set up fbdev, which is also register the driver at least to the fbdev world, so really the same). > > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> > > --- > > drivers/gpu/drm/drm_drv.c | 4 ++-- > > drivers/gpu/drm/drm_mode_object.c | 4 ++++ > > 2 files changed, 6 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > > index cb6f0245de7c..48c84e3e1931 100644 > > --- a/drivers/gpu/drm/drm_drv.c > > +++ b/drivers/gpu/drm/drm_drv.c > > @@ -997,14 +997,14 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags) > > if (ret) > > goto err_minors; > > > > - dev->registered = true; > > - > > if (dev->driver->load) { > > ret = dev->driver->load(dev, flags); > > if (ret) > > goto err_minors; > > } > > > > + dev->registered = true; > > + > > if (drm_core_check_feature(dev, DRIVER_MODESET)) > > drm_modeset_register_all(dev); > > > > diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c > > index 1c6e51135962..c355ba8e6d5d 100644 > > --- a/drivers/gpu/drm/drm_mode_object.c > > +++ b/drivers/gpu/drm/drm_mode_object.c > > @@ -42,6 +42,8 @@ int __drm_mode_object_add(struct drm_device *dev, struct drm_mode_object *obj, > > { > > int ret; > > > > + WARN_ON(dev->registered && !obj_free_cb); > > These should probably have a comment above them giving some guidance to the > driver developer. > > With some comments, this is: What comment do you expect here? drm_dev_register explains what you should do already, and I expect driver developers to find that one pretty quickly. From there: "This should be done last in the device initialization sequence to make sure userspace can't access an inconsistent state." -Daniel > Reviewed-by: Sean Paul <sean@xxxxxxxxxx> > > > > + > > mutex_lock(&dev->mode_config.idr_mutex); > > ret = idr_alloc(&dev->mode_config.object_idr, register_obj ? obj : NULL, > > 1, 0, GFP_KERNEL); > > @@ -102,6 +104,8 @@ void drm_mode_object_register(struct drm_device *dev, > > void drm_mode_object_unregister(struct drm_device *dev, > > struct drm_mode_object *object) > > { > > + WARN_ON(dev->registered && !object->free_cb); > > + > > mutex_lock(&dev->mode_config.idr_mutex); > > if (object->id) { > > idr_remove(&dev->mode_config.object_idr, object->id); > > -- > > 2.20.1 > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@xxxxxxxxxxxxxxxxxxxxx > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > > -- > Sean Paul, Software Engineer, Google / Chromium OS -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel