diff options
Diffstat (limited to 'kernel/drivers/gpu/drm/drm_auth.c')
| -rw-r--r-- | kernel/drivers/gpu/drm/drm_auth.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/kernel/drivers/gpu/drm/drm_auth.c b/kernel/drivers/gpu/drm/drm_auth.c new file mode 100644 index 000000000..fc8e8aaa3 --- /dev/null +++ b/kernel/drivers/gpu/drm/drm_auth.c @@ -0,0 +1,201 @@ +/** + * \file drm_auth.c + * IOCTLs for authentication + * + * \author Rickard E. (Rik) Faith <faith@valinux.com> + * \author Gareth Hughes <gareth@valinux.com> + */ + +/* + * 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. + * + * 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" + +struct drm_magic_entry { + struct list_head head; + struct drm_hash_item hash_item; + struct drm_file *priv; +}; + +/** + * Find the file with the given magic number. + * + * \param dev DRM device. + * \param magic magic number. + * + * Searches in drm_device::magiclist within all files with the same hash key + * the one with matching magic number, while holding the drm_device::struct_mutex + * lock. + */ +static struct drm_file *drm_find_file(struct drm_master *master, drm_magic_t magic) +{ + struct drm_file *retval = NULL; + struct drm_magic_entry *pt; + struct drm_hash_item *hash; + struct drm_device *dev = master->minor->dev; + + mutex_lock(&dev->struct_mutex); + if (!drm_ht_find_item(&master->magiclist, (unsigned long)magic, &hash)) { + pt = drm_hash_entry(hash, struct drm_magic_entry, hash_item); + retval = pt->priv; + } + mutex_unlock(&dev->struct_mutex); + return retval; +} + +/** + * Adds a magic number. + * + * \param dev DRM device. + * \param priv file private data. + * \param magic magic number. + * + * Creates a drm_magic_entry structure and appends to the linked list + * associated the magic number hash key in drm_device::magiclist, while holding + * the drm_device::struct_mutex lock. + */ +static int drm_add_magic(struct drm_master *master, struct drm_file *priv, + drm_magic_t magic) +{ + struct drm_magic_entry *entry; + struct drm_device *dev = master->minor->dev; + DRM_DEBUG("%d\n", magic); + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + entry->priv = priv; + entry->hash_item.key = (unsigned long)magic; + mutex_lock(&dev->struct_mutex); + drm_ht_insert_item(&master->magiclist, &entry->hash_item); + list_add_tail(&entry->head, &master->magicfree); + mutex_unlock(&dev->struct_mutex); + + return 0; +} + +/** + * Remove a magic number. + * + * \param dev DRM device. + * \param magic magic number. + * + * Searches and unlinks the entry in drm_device::magiclist with the magic + * number hash key, while holding the drm_device::struct_mutex lock. + */ +int drm_remove_magic(struct drm_master *master, drm_magic_t magic) +{ + struct drm_magic_entry *pt; + struct drm_hash_item *hash; + struct drm_device *dev = master->minor->dev; + + DRM_DEBUG("%d\n", magic); + + mutex_lock(&dev->struct_mutex); + if (drm_ht_find_item(&master->magiclist, (unsigned long)magic, &hash)) { + mutex_unlock(&dev->struct_mutex); + return -EINVAL; + } + pt = drm_hash_entry(hash, struct drm_magic_entry, hash_item); + drm_ht_remove_item(&master->magiclist, hash); + list_del(&pt->head); + mutex_unlock(&dev->struct_mutex); + + kfree(pt); + + return 0; +} + +/** + * Get a unique magic number (ioctl). + * + * \param inode device inode. + * \param file_priv DRM file private. + * \param cmd command. + * \param arg pointer to a resulting drm_auth structure. + * \return zero on success, or a negative number on failure. + * + * If there is a magic number in drm_file::magic then use it, otherwise + * searches an unique non-zero magic number and add it associating it with \p + * file_priv. + * This ioctl needs protection by the drm_global_mutex, which protects + * struct drm_file::magic and struct drm_magic_entry::priv. + */ +int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) +{ + static drm_magic_t sequence = 0; + static DEFINE_SPINLOCK(lock); + struct drm_auth *auth = data; + + /* Find unique magic */ + if (file_priv->magic) { + auth->magic = file_priv->magic; + } else { + do { + spin_lock(&lock); + if (!sequence) + ++sequence; /* reserve 0 */ + auth->magic = sequence++; + spin_unlock(&lock); + } while (drm_find_file(file_priv->master, auth->magic)); + file_priv->magic = auth->magic; + drm_add_magic(file_priv->master, file_priv, auth->magic); + } + + DRM_DEBUG("%u\n", auth->magic); + + return 0; +} + +/** + * Authenticate with a magic. + * + * \param inode device inode. + * \param file_priv DRM file private. + * \param cmd command. + * \param arg pointer to a drm_auth structure. + * \return zero if authentication successed, or a negative number otherwise. + * + * Checks if \p file_priv is associated with the magic number passed in \arg. + * This ioctl needs protection by the drm_global_mutex, which protects + * struct drm_file::magic and struct drm_magic_entry::priv. + */ +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); + if ((file = drm_find_file(file_priv->master, auth->magic))) { + file->authenticated = 1; + drm_remove_magic(file_priv->master, auth->magic); + return 0; + } + return -EINVAL; +} |