1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/**
* \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 "drmP.h"
/**
* 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;
}
|
