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path: root/drivers/char/raw.c
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-rw-r--r--drivers/char/raw.c291
1 files changed, 172 insertions, 119 deletions
diff --git a/drivers/char/raw.c b/drivers/char/raw.c
index b38942f6bf31..b33e8ea314ed 100644
--- a/drivers/char/raw.c
+++ b/drivers/char/raw.c
@@ -19,8 +19,9 @@
19#include <linux/cdev.h> 19#include <linux/cdev.h>
20#include <linux/device.h> 20#include <linux/device.h>
21#include <linux/mutex.h> 21#include <linux/mutex.h>
22#include <linux/smp_lock.h>
23#include <linux/gfp.h> 22#include <linux/gfp.h>
23#include <linux/compat.h>
24#include <linux/vmalloc.h>
24 25
25#include <asm/uaccess.h> 26#include <asm/uaccess.h>
26 27
@@ -30,10 +31,15 @@ struct raw_device_data {
30}; 31};
31 32
32static struct class *raw_class; 33static struct class *raw_class;
33static struct raw_device_data raw_devices[MAX_RAW_MINORS]; 34static struct raw_device_data *raw_devices;
34static DEFINE_MUTEX(raw_mutex); 35static DEFINE_MUTEX(raw_mutex);
35static const struct file_operations raw_ctl_fops; /* forward declaration */ 36static const struct file_operations raw_ctl_fops; /* forward declaration */
36 37
38static int max_raw_minors = MAX_RAW_MINORS;
39
40module_param(max_raw_minors, int, 0);
41MODULE_PARM_DESC(max_raw_minors, "Maximum number of raw devices (1-65536)");
42
37/* 43/*
38 * Open/close code for raw IO. 44 * Open/close code for raw IO.
39 * 45 *
@@ -55,7 +61,6 @@ static int raw_open(struct inode *inode, struct file *filp)
55 return 0; 61 return 0;
56 } 62 }
57 63
58 lock_kernel();
59 mutex_lock(&raw_mutex); 64 mutex_lock(&raw_mutex);
60 65
61 /* 66 /*
@@ -66,15 +71,12 @@ static int raw_open(struct inode *inode, struct file *filp)
66 if (!bdev) 71 if (!bdev)
67 goto out; 72 goto out;
68 igrab(bdev->bd_inode); 73 igrab(bdev->bd_inode);
69 err = blkdev_get(bdev, filp->f_mode); 74 err = blkdev_get(bdev, filp->f_mode | FMODE_EXCL, raw_open);
70 if (err) 75 if (err)
71 goto out; 76 goto out;
72 err = bd_claim(bdev, raw_open);
73 if (err)
74 goto out1;
75 err = set_blocksize(bdev, bdev_logical_block_size(bdev)); 77 err = set_blocksize(bdev, bdev_logical_block_size(bdev));
76 if (err) 78 if (err)
77 goto out2; 79 goto out1;
78 filp->f_flags |= O_DIRECT; 80 filp->f_flags |= O_DIRECT;
79 filp->f_mapping = bdev->bd_inode->i_mapping; 81 filp->f_mapping = bdev->bd_inode->i_mapping;
80 if (++raw_devices[minor].inuse == 1) 82 if (++raw_devices[minor].inuse == 1)
@@ -82,16 +84,12 @@ static int raw_open(struct inode *inode, struct file *filp)
82 bdev->bd_inode->i_mapping; 84 bdev->bd_inode->i_mapping;
83 filp->private_data = bdev; 85 filp->private_data = bdev;
84 mutex_unlock(&raw_mutex); 86 mutex_unlock(&raw_mutex);
85 unlock_kernel();
86 return 0; 87 return 0;
87 88
88out2:
89 bd_release(bdev);
90out1: 89out1:
91 blkdev_put(bdev, filp->f_mode); 90 blkdev_put(bdev, filp->f_mode | FMODE_EXCL);
92out: 91out:
93 mutex_unlock(&raw_mutex); 92 mutex_unlock(&raw_mutex);
94 unlock_kernel();
95 return err; 93 return err;
96} 94}
97 95
@@ -113,8 +111,7 @@ static int raw_release(struct inode *inode, struct file *filp)
113 } 111 }
114 mutex_unlock(&raw_mutex); 112 mutex_unlock(&raw_mutex);
115 113
116 bd_release(bdev); 114 blkdev_put(bdev, filp->f_mode | FMODE_EXCL);
117 blkdev_put(bdev, filp->f_mode);
118 return 0; 115 return 0;
119} 116}
120 117
@@ -125,20 +122,84 @@ static long
125raw_ioctl(struct file *filp, unsigned int command, unsigned long arg) 122raw_ioctl(struct file *filp, unsigned int command, unsigned long arg)
126{ 123{
127 struct block_device *bdev = filp->private_data; 124 struct block_device *bdev = filp->private_data;
128 int ret; 125 return blkdev_ioctl(bdev, 0, command, arg);
126}
129 127
130 lock_kernel(); 128static int bind_set(int number, u64 major, u64 minor)
131 ret = blkdev_ioctl(bdev, 0, command, arg); 129{
132 unlock_kernel(); 130 dev_t dev = MKDEV(major, minor);
131 struct raw_device_data *rawdev;
132 int err = 0;
133 133
134 return ret; 134 if (number <= 0 || number >= max_raw_minors)
135 return -EINVAL;
136
137 if (MAJOR(dev) != major || MINOR(dev) != minor)
138 return -EINVAL;
139
140 rawdev = &raw_devices[number];
141
142 /*
143 * This is like making block devices, so demand the
144 * same capability
145 */
146 if (!capable(CAP_SYS_ADMIN))
147 return -EPERM;
148
149 /*
150 * For now, we don't need to check that the underlying
151 * block device is present or not: we can do that when
152 * the raw device is opened. Just check that the
153 * major/minor numbers make sense.
154 */
155
156 if (MAJOR(dev) == 0 && dev != 0)
157 return -EINVAL;
158
159 mutex_lock(&raw_mutex);
160 if (rawdev->inuse) {
161 mutex_unlock(&raw_mutex);
162 return -EBUSY;
163 }
164 if (rawdev->binding) {
165 bdput(rawdev->binding);
166 module_put(THIS_MODULE);
167 }
168 if (!dev) {
169 /* unbind */
170 rawdev->binding = NULL;
171 device_destroy(raw_class, MKDEV(RAW_MAJOR, number));
172 } else {
173 rawdev->binding = bdget(dev);
174 if (rawdev->binding == NULL) {
175 err = -ENOMEM;
176 } else {
177 dev_t raw = MKDEV(RAW_MAJOR, number);
178 __module_get(THIS_MODULE);
179 device_destroy(raw_class, raw);
180 device_create(raw_class, NULL, raw, NULL,
181 "raw%d", number);
182 }
183 }
184 mutex_unlock(&raw_mutex);
185 return err;
135} 186}
136 187
137static void bind_device(struct raw_config_request *rq) 188static int bind_get(int number, dev_t *dev)
138{ 189{
139 device_destroy(raw_class, MKDEV(RAW_MAJOR, rq->raw_minor)); 190 struct raw_device_data *rawdev;
140 device_create(raw_class, NULL, MKDEV(RAW_MAJOR, rq->raw_minor), NULL, 191 struct block_device *bdev;
141 "raw%d", rq->raw_minor); 192
193 if (number <= 0 || number >= MAX_RAW_MINORS)
194 return -EINVAL;
195
196 rawdev = &raw_devices[number];
197
198 mutex_lock(&raw_mutex);
199 bdev = rawdev->binding;
200 *dev = bdev ? bdev->bd_dev : 0;
201 mutex_unlock(&raw_mutex);
202 return 0;
142} 203}
143 204
144/* 205/*
@@ -149,106 +210,79 @@ static long raw_ctl_ioctl(struct file *filp, unsigned int command,
149 unsigned long arg) 210 unsigned long arg)
150{ 211{
151 struct raw_config_request rq; 212 struct raw_config_request rq;
152 struct raw_device_data *rawdev; 213 dev_t dev;
153 int err = 0; 214 int err;
154 215
155 lock_kernel();
156 switch (command) { 216 switch (command) {
157 case RAW_SETBIND: 217 case RAW_SETBIND:
218 if (copy_from_user(&rq, (void __user *) arg, sizeof(rq)))
219 return -EFAULT;
220
221 return bind_set(rq.raw_minor, rq.block_major, rq.block_minor);
222
158 case RAW_GETBIND: 223 case RAW_GETBIND:
224 if (copy_from_user(&rq, (void __user *) arg, sizeof(rq)))
225 return -EFAULT;
159 226
160 /* First, find out which raw minor we want */ 227 err = bind_get(rq.raw_minor, &dev);
228 if (err)
229 return err;
161 230
162 if (copy_from_user(&rq, (void __user *) arg, sizeof(rq))) { 231 rq.block_major = MAJOR(dev);
163 err = -EFAULT; 232 rq.block_minor = MINOR(dev);
164 goto out;
165 }
166 233
167 if (rq.raw_minor <= 0 || rq.raw_minor >= MAX_RAW_MINORS) { 234 if (copy_to_user((void __user *)arg, &rq, sizeof(rq)))
168 err = -EINVAL; 235 return -EFAULT;
169 goto out; 236
170 } 237 return 0;
171 rawdev = &raw_devices[rq.raw_minor];
172
173 if (command == RAW_SETBIND) {
174 dev_t dev;
175
176 /*
177 * This is like making block devices, so demand the
178 * same capability
179 */
180 if (!capable(CAP_SYS_ADMIN)) {
181 err = -EPERM;
182 goto out;
183 }
184
185 /*
186 * For now, we don't need to check that the underlying
187 * block device is present or not: we can do that when
188 * the raw device is opened. Just check that the
189 * major/minor numbers make sense.
190 */
191
192 dev = MKDEV(rq.block_major, rq.block_minor);
193 if ((rq.block_major == 0 && rq.block_minor != 0) ||
194 MAJOR(dev) != rq.block_major ||
195 MINOR(dev) != rq.block_minor) {
196 err = -EINVAL;
197 goto out;
198 }
199
200 mutex_lock(&raw_mutex);
201 if (rawdev->inuse) {
202 mutex_unlock(&raw_mutex);
203 err = -EBUSY;
204 goto out;
205 }
206 if (rawdev->binding) {
207 bdput(rawdev->binding);
208 module_put(THIS_MODULE);
209 }
210 if (rq.block_major == 0 && rq.block_minor == 0) {
211 /* unbind */
212 rawdev->binding = NULL;
213 device_destroy(raw_class,
214 MKDEV(RAW_MAJOR, rq.raw_minor));
215 } else {
216 rawdev->binding = bdget(dev);
217 if (rawdev->binding == NULL)
218 err = -ENOMEM;
219 else {
220 __module_get(THIS_MODULE);
221 bind_device(&rq);
222 }
223 }
224 mutex_unlock(&raw_mutex);
225 } else {
226 struct block_device *bdev;
227
228 mutex_lock(&raw_mutex);
229 bdev = rawdev->binding;
230 if (bdev) {
231 rq.block_major = MAJOR(bdev->bd_dev);
232 rq.block_minor = MINOR(bdev->bd_dev);
233 } else {
234 rq.block_major = rq.block_minor = 0;
235 }
236 mutex_unlock(&raw_mutex);
237 if (copy_to_user((void __user *)arg, &rq, sizeof(rq))) {
238 err = -EFAULT;
239 goto out;
240 }
241 }
242 break;
243 default:
244 err = -EINVAL;
245 break;
246 } 238 }
247out: 239
248 unlock_kernel(); 240 return -EINVAL;
249 return err;
250} 241}
251 242
243#ifdef CONFIG_COMPAT
244struct raw32_config_request {
245 compat_int_t raw_minor;
246 compat_u64 block_major;
247 compat_u64 block_minor;
248};
249
250static long raw_ctl_compat_ioctl(struct file *file, unsigned int cmd,
251 unsigned long arg)
252{
253 struct raw32_config_request __user *user_req = compat_ptr(arg);
254 struct raw32_config_request rq;
255 dev_t dev;
256 int err = 0;
257
258 switch (cmd) {
259 case RAW_SETBIND:
260 if (copy_from_user(&rq, user_req, sizeof(rq)))
261 return -EFAULT;
262
263 return bind_set(rq.raw_minor, rq.block_major, rq.block_minor);
264
265 case RAW_GETBIND:
266 if (copy_from_user(&rq, user_req, sizeof(rq)))
267 return -EFAULT;
268
269 err = bind_get(rq.raw_minor, &dev);
270 if (err)
271 return err;
272
273 rq.block_major = MAJOR(dev);
274 rq.block_minor = MINOR(dev);
275
276 if (copy_to_user(user_req, &rq, sizeof(rq)))
277 return -EFAULT;
278
279 return 0;
280 }
281
282 return -EINVAL;
283}
284#endif
285
252static const struct file_operations raw_fops = { 286static const struct file_operations raw_fops = {
253 .read = do_sync_read, 287 .read = do_sync_read,
254 .aio_read = generic_file_aio_read, 288 .aio_read = generic_file_aio_read,
@@ -258,13 +292,18 @@ static const struct file_operations raw_fops = {
258 .open = raw_open, 292 .open = raw_open,
259 .release = raw_release, 293 .release = raw_release,
260 .unlocked_ioctl = raw_ioctl, 294 .unlocked_ioctl = raw_ioctl,
295 .llseek = default_llseek,
261 .owner = THIS_MODULE, 296 .owner = THIS_MODULE,
262}; 297};
263 298
264static const struct file_operations raw_ctl_fops = { 299static const struct file_operations raw_ctl_fops = {
265 .unlocked_ioctl = raw_ctl_ioctl, 300 .unlocked_ioctl = raw_ctl_ioctl,
301#ifdef CONFIG_COMPAT
302 .compat_ioctl = raw_ctl_compat_ioctl,
303#endif
266 .open = raw_open, 304 .open = raw_open,
267 .owner = THIS_MODULE, 305 .owner = THIS_MODULE,
306 .llseek = noop_llseek,
268}; 307};
269 308
270static struct cdev raw_cdev; 309static struct cdev raw_cdev;
@@ -279,14 +318,27 @@ static int __init raw_init(void)
279 dev_t dev = MKDEV(RAW_MAJOR, 0); 318 dev_t dev = MKDEV(RAW_MAJOR, 0);
280 int ret; 319 int ret;
281 320
282 ret = register_chrdev_region(dev, MAX_RAW_MINORS, "raw"); 321 if (max_raw_minors < 1 || max_raw_minors > 65536) {
322 printk(KERN_WARNING "raw: invalid max_raw_minors (must be"
323 " between 1 and 65536), using %d\n", MAX_RAW_MINORS);
324 max_raw_minors = MAX_RAW_MINORS;
325 }
326
327 raw_devices = vmalloc(sizeof(struct raw_device_data) * max_raw_minors);
328 if (!raw_devices) {
329 printk(KERN_ERR "Not enough memory for raw device structures\n");
330 ret = -ENOMEM;
331 goto error;
332 }
333 memset(raw_devices, 0, sizeof(struct raw_device_data) * max_raw_minors);
334
335 ret = register_chrdev_region(dev, max_raw_minors, "raw");
283 if (ret) 336 if (ret)
284 goto error; 337 goto error;
285 338
286 cdev_init(&raw_cdev, &raw_fops); 339 cdev_init(&raw_cdev, &raw_fops);
287 ret = cdev_add(&raw_cdev, dev, MAX_RAW_MINORS); 340 ret = cdev_add(&raw_cdev, dev, max_raw_minors);
288 if (ret) { 341 if (ret) {
289 kobject_put(&raw_cdev.kobj);
290 goto error_region; 342 goto error_region;
291 } 343 }
292 344
@@ -303,8 +355,9 @@ static int __init raw_init(void)
303 return 0; 355 return 0;
304 356
305error_region: 357error_region:
306 unregister_chrdev_region(dev, MAX_RAW_MINORS); 358 unregister_chrdev_region(dev, max_raw_minors);
307error: 359error:
360 vfree(raw_devices);
308 return ret; 361 return ret;
309} 362}
310 363
@@ -313,7 +366,7 @@ static void __exit raw_exit(void)
313 device_destroy(raw_class, MKDEV(RAW_MAJOR, 0)); 366 device_destroy(raw_class, MKDEV(RAW_MAJOR, 0));
314 class_destroy(raw_class); 367 class_destroy(raw_class);
315 cdev_del(&raw_cdev); 368 cdev_del(&raw_cdev);
316 unregister_chrdev_region(MKDEV(RAW_MAJOR, 0), MAX_RAW_MINORS); 369 unregister_chrdev_region(MKDEV(RAW_MAJOR, 0), max_raw_minors);
317} 370}
318 371
319module_init(raw_init); 372module_init(raw_init);
generated by cgit v1.2.2 (git 2.25.0) at 2025-04-03 04:56:34 -0400