| /* |
| * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com |
| * |
| * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. |
| * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. |
| * All Rights Reserved. |
| * |
| * Author Rickard E. (Rik) Faith <faith@valinux.com> |
| * Author Gareth Hughes <gareth@valinux.com> |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR |
| * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
| * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| * OTHER DEALINGS IN THE SOFTWARE. |
| */ |
| |
| #include <drm/drmP.h> |
| #include "drm_internal.h" |
| #include "drm_legacy.h" |
| |
| /** |
| * DOC: master and authentication |
| * |
| * struct &drm_master is used to track groups of clients with open |
| * primary/legacy device nodes. For every struct &drm_file which has had at |
| * least once successfully became the device master (either through the |
| * SET_MASTER IOCTL, or implicitly through opening the primary device node when |
| * no one else is the current master that time) there exists one &drm_master. |
| * This is noted in the is_master member of &drm_file. All other clients have |
| * just a pointer to the &drm_master they are associated with. |
| * |
| * In addition only one &drm_master can be the current master for a &drm_device. |
| * It can be switched through the DROP_MASTER and SET_MASTER IOCTL, or |
| * implicitly through closing/openeing the primary device node. See also |
| * drm_is_current_master(). |
| * |
| * Clients can authenticate against the current master (if it matches their own) |
| * using the GETMAGIC and AUTHMAGIC IOCTLs. Together with exchanging masters, |
| * this allows controlled access to the device for an entire group of mutually |
| * trusted clients. |
| */ |
| |
| int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) |
| { |
| struct drm_auth *auth = data; |
| int ret = 0; |
| |
| mutex_lock(&dev->master_mutex); |
| if (!file_priv->magic) { |
| ret = idr_alloc(&file_priv->master->magic_map, file_priv, |
| 1, 0, GFP_KERNEL); |
| if (ret >= 0) |
| file_priv->magic = ret; |
| } |
| auth->magic = file_priv->magic; |
| mutex_unlock(&dev->master_mutex); |
| |
| DRM_DEBUG("%u\n", auth->magic); |
| |
| return ret < 0 ? ret : 0; |
| } |
| |
| int drm_authmagic(struct drm_device *dev, void *data, |
| struct drm_file *file_priv) |
| { |
| struct drm_auth *auth = data; |
| struct drm_file *file; |
| |
| DRM_DEBUG("%u\n", auth->magic); |
| |
| mutex_lock(&dev->master_mutex); |
| file = idr_find(&file_priv->master->magic_map, auth->magic); |
| if (file) { |
| file->authenticated = 1; |
| idr_replace(&file_priv->master->magic_map, NULL, auth->magic); |
| } |
| mutex_unlock(&dev->master_mutex); |
| |
| return file ? 0 : -EINVAL; |
| } |
| |
| static struct drm_master *drm_master_create(struct drm_device *dev) |
| { |
| struct drm_master *master; |
| |
| master = kzalloc(sizeof(*master), GFP_KERNEL); |
| if (!master) |
| return NULL; |
| |
| kref_init(&master->refcount); |
| spin_lock_init(&master->lock.spinlock); |
| init_waitqueue_head(&master->lock.lock_queue); |
| idr_init(&master->magic_map); |
| master->dev = dev; |
| |
| return master; |
| } |
| |
| static int drm_set_master(struct drm_device *dev, struct drm_file *fpriv, |
| bool new_master) |
| { |
| int ret = 0; |
| |
| dev->master = drm_master_get(fpriv->master); |
| if (dev->driver->master_set) { |
| ret = dev->driver->master_set(dev, fpriv, new_master); |
| if (unlikely(ret != 0)) { |
| drm_master_put(&dev->master); |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) |
| { |
| struct drm_master *old_master; |
| int ret; |
| |
| lockdep_assert_held_once(&dev->master_mutex); |
| |
| old_master = fpriv->master; |
| fpriv->master = drm_master_create(dev); |
| if (!fpriv->master) { |
| fpriv->master = old_master; |
| return -ENOMEM; |
| } |
| |
| if (dev->driver->master_create) { |
| ret = dev->driver->master_create(dev, fpriv->master); |
| if (ret) |
| goto out_err; |
| } |
| fpriv->is_master = 1; |
| fpriv->authenticated = 1; |
| |
| ret = drm_set_master(dev, fpriv, true); |
| if (ret) |
| goto out_err; |
| |
| if (old_master) |
| drm_master_put(&old_master); |
| |
| return 0; |
| |
| out_err: |
| /* drop references and restore old master on failure */ |
| drm_master_put(&fpriv->master); |
| fpriv->master = old_master; |
| |
| return ret; |
| } |
| |
| int drm_setmaster_ioctl(struct drm_device *dev, void *data, |
| struct drm_file *file_priv) |
| { |
| int ret = 0; |
| |
| mutex_lock(&dev->master_mutex); |
| if (drm_is_current_master(file_priv)) |
| goto out_unlock; |
| |
| if (dev->master) { |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| |
| if (!file_priv->master) { |
| ret = -EINVAL; |
| goto out_unlock; |
| } |
| |
| if (!file_priv->is_master) { |
| ret = drm_new_set_master(dev, file_priv); |
| goto out_unlock; |
| } |
| |
| ret = drm_set_master(dev, file_priv, false); |
| out_unlock: |
| mutex_unlock(&dev->master_mutex); |
| return ret; |
| } |
| |
| static void drm_drop_master(struct drm_device *dev, |
| struct drm_file *fpriv) |
| { |
| if (dev->driver->master_drop) |
| dev->driver->master_drop(dev, fpriv); |
| drm_master_put(&dev->master); |
| } |
| |
| int drm_dropmaster_ioctl(struct drm_device *dev, void *data, |
| struct drm_file *file_priv) |
| { |
| int ret = -EINVAL; |
| |
| mutex_lock(&dev->master_mutex); |
| if (!drm_is_current_master(file_priv)) |
| goto out_unlock; |
| |
| if (!dev->master) |
| goto out_unlock; |
| |
| ret = 0; |
| drm_drop_master(dev, file_priv); |
| out_unlock: |
| mutex_unlock(&dev->master_mutex); |
| return ret; |
| } |
| |
| int drm_master_open(struct drm_file *file_priv) |
| { |
| struct drm_device *dev = file_priv->minor->dev; |
| int ret = 0; |
| |
| /* if there is no current master make this fd it, but do not create |
| * any master object for render clients */ |
| mutex_lock(&dev->master_mutex); |
| if (!dev->master) |
| ret = drm_new_set_master(dev, file_priv); |
| else |
| file_priv->master = drm_master_get(dev->master); |
| mutex_unlock(&dev->master_mutex); |
| |
| return ret; |
| } |
| |
| void drm_master_release(struct drm_file *file_priv) |
| { |
| struct drm_device *dev = file_priv->minor->dev; |
| struct drm_master *master = file_priv->master; |
| |
| mutex_lock(&dev->master_mutex); |
| if (file_priv->magic) |
| idr_remove(&file_priv->master->magic_map, file_priv->magic); |
| |
| if (!drm_is_current_master(file_priv)) |
| goto out; |
| |
| if (!drm_core_check_feature(dev, DRIVER_MODESET)) { |
| /* |
| * Since the master is disappearing, so is the |
| * possibility to lock. |
| */ |
| mutex_lock(&dev->struct_mutex); |
| if (master->lock.hw_lock) { |
| if (dev->sigdata.lock == master->lock.hw_lock) |
| dev->sigdata.lock = NULL; |
| master->lock.hw_lock = NULL; |
| master->lock.file_priv = NULL; |
| wake_up_interruptible_all(&master->lock.lock_queue); |
| } |
| mutex_unlock(&dev->struct_mutex); |
| } |
| |
| if (dev->master == file_priv->master) |
| drm_drop_master(dev, file_priv); |
| out: |
| /* drop the master reference held by the file priv */ |
| if (file_priv->master) |
| drm_master_put(&file_priv->master); |
| mutex_unlock(&dev->master_mutex); |
| } |
| |
| /** |
| * drm_is_current_master - checks whether @priv is the current master |
| * @fpriv: DRM file private |
| * |
| * Checks whether @fpriv is current master on its device. This decides whether a |
| * client is allowed to run DRM_MASTER IOCTLs. |
| * |
| * Most of the modern IOCTL which require DRM_MASTER are for kernel modesetting |
| * - the current master is assumed to own the non-shareable display hardware. |
| */ |
| bool drm_is_current_master(struct drm_file *fpriv) |
| { |
| return fpriv->is_master && fpriv->master == fpriv->minor->dev->master; |
| } |
| EXPORT_SYMBOL(drm_is_current_master); |
| |
| /** |
| * drm_master_get - reference a master pointer |
| * @master: struct &drm_master |
| * |
| * Increments the reference count of @master and returns a pointer to @master. |
| */ |
| struct drm_master *drm_master_get(struct drm_master *master) |
| { |
| kref_get(&master->refcount); |
| return master; |
| } |
| EXPORT_SYMBOL(drm_master_get); |
| |
| static void drm_master_destroy(struct kref *kref) |
| { |
| struct drm_master *master = container_of(kref, struct drm_master, refcount); |
| struct drm_device *dev = master->dev; |
| |
| if (dev->driver->master_destroy) |
| dev->driver->master_destroy(dev, master); |
| |
| drm_legacy_master_rmmaps(dev, master); |
| |
| idr_destroy(&master->magic_map); |
| kfree(master->unique); |
| kfree(master); |
| } |
| |
| /** |
| * drm_master_put - unreference and clear a master pointer |
| * @master: pointer to a pointer of struct &drm_master |
| * |
| * This decrements the &drm_master behind @master and sets it to NULL. |
| */ |
| void drm_master_put(struct drm_master **master) |
| { |
| kref_put(&(*master)->refcount, drm_master_destroy); |
| *master = NULL; |
| } |
| EXPORT_SYMBOL(drm_master_put); |