/* * 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 &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;} 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_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:	/* 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);