diff options
Diffstat (limited to 'drivers/gpu/drm/drm_auth.c')
| -rw-r--r-- | drivers/gpu/drm/drm_auth.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c new file mode 100644 index 000000000..ce098eb57 --- /dev/null +++ b/drivers/gpu/drm/drm_auth.c @@ -0,0 +1,371 @@ +/* + * 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" +#include <drm/drm_lease.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 &drm_file.is_master. 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; +} + +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; + + /* initialize the tree of output resource lessees */ + master->lessor = NULL; + master->lessee_id = 0; + INIT_LIST_HEAD(&master->lessees); + INIT_LIST_HEAD(&master->lessee_list); + idr_init(&master->leases); + idr_init(&master->lessee_idr); + + 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); + + WARN_ON(fpriv->is_master); + 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; + fpriv->is_master = 0; + + 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; + } + + if (file_priv->master->lessor != NULL) { + DRM_DEBUG_LEASE("Attempt to set lessee %d as master\n", file_priv->master->lessee_id); + ret = -EINVAL; + 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; + + if (file_priv->master->lessor != NULL) { + DRM_DEBUG_LEASE("Attempt to drop lessee %d as master\n", file_priv->master->lessee_id); + ret = -EINVAL; + 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; + + mutex_lock(&dev->master_mutex); + master = file_priv->master; + 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_LEGACY)) { + /* + * 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: + if (drm_core_check_feature(dev, DRIVER_MODESET) && file_priv->is_master) { + /* Revoke any leases held by this or lessees, but only if + * this is the "real" master + */ + drm_lease_revoke(master); + } + + /* 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 && drm_lease_owner(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 (drm_core_check_feature(dev, DRIVER_MODESET)) + drm_lease_destroy(master); + + if (dev->driver->master_destroy) + dev->driver->master_destroy(dev, master); + + drm_legacy_master_rmmaps(dev, master); + + idr_destroy(&master->magic_map); + idr_destroy(&master->leases); + idr_destroy(&master->lessee_idr); + + 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); |