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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2007-08-30 00:22:18 -0400
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2007-08-30 00:22:18 -0400
commit6addb1d6de1968b84852f54561cc9a999909b5a9 (patch)
tree568526cfdd11abb953cd69db2f7059c582ebe9d4
parent8006479c9b75fb6594a7b746af3d7f1fbb68f18f (diff)
Input: evdev - implement proper locking
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat
-rw-r--r--drivers/input/evdev.c713
1 files changed, 473 insertions, 240 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index ab4b2d9b5327..bfee4f9a7715 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -30,6 +30,8 @@ struct evdev {
30 wait_queue_head_t wait; 30 wait_queue_head_t wait;
31 struct evdev_client *grab; 31 struct evdev_client *grab;
32 struct list_head client_list; 32 struct list_head client_list;
33 spinlock_t client_lock; /* protects client_list */
34 struct mutex mutex;
33 struct device dev; 35 struct device dev;
34}; 36};
35 37
@@ -37,39 +39,53 @@ struct evdev_client {
37 struct input_event buffer[EVDEV_BUFFER_SIZE]; 39 struct input_event buffer[EVDEV_BUFFER_SIZE];
38 int head; 40 int head;
39 int tail; 41 int tail;
42 spinlock_t buffer_lock; /* protects access to buffer, head and tail */
40 struct fasync_struct *fasync; 43 struct fasync_struct *fasync;
41 struct evdev *evdev; 44 struct evdev *evdev;
42 struct list_head node; 45 struct list_head node;
43}; 46};
44 47
45static struct evdev *evdev_table[EVDEV_MINORS]; 48static struct evdev *evdev_table[EVDEV_MINORS];
49static DEFINE_MUTEX(evdev_table_mutex);
46 50
47static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value) 51static void evdev_pass_event(struct evdev_client *client,
52 struct input_event *event)
53{
54 /*
55 * Interrupts are disabled, just acquire the lock
56 */
57 spin_lock(&client->buffer_lock);
58 client->buffer[client->head++] = *event;
59 client->head &= EVDEV_BUFFER_SIZE - 1;
60 spin_unlock(&client->buffer_lock);
61
62 kill_fasync(&client->fasync, SIGIO, POLL_IN);
63}
64
65/*
66 * Pass incoming event to all connected clients. Note that we are
67 * caleld under a spinlock with interrupts off so we don't need
68 * to use rcu_read_lock() here. Writers will be using syncronize_sched()
69 * instead of synchrnoize_rcu().
70 */
71static void evdev_event(struct input_handle *handle,
72 unsigned int type, unsigned int code, int value)
48{ 73{
49 struct evdev *evdev = handle->private; 74 struct evdev *evdev = handle->private;
50 struct evdev_client *client; 75 struct evdev_client *client;
76 struct input_event event;
51 77
52 if (evdev->grab) { 78 do_gettimeofday(&event.time);
53 client = evdev->grab; 79 event.type = type;
54 80 event.code = code;
55 do_gettimeofday(&client->buffer[client->head].time); 81 event.value = value;
56 client->buffer[client->head].type = type;
57 client->buffer[client->head].code = code;
58 client->buffer[client->head].value = value;
59 client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1);
60
61 kill_fasync(&client->fasync, SIGIO, POLL_IN);
62 } else
63 list_for_each_entry(client, &evdev->client_list, node) {
64
65 do_gettimeofday(&client->buffer[client->head].time);
66 client->buffer[client->head].type = type;
67 client->buffer[client->head].code = code;
68 client->buffer[client->head].value = value;
69 client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1);
70 82
71 kill_fasync(&client->fasync, SIGIO, POLL_IN); 83 client = rcu_dereference(evdev->grab);
72 } 84 if (client)
85 evdev_pass_event(client, &event);
86 else
87 list_for_each_entry_rcu(client, &evdev->client_list, node)
88 evdev_pass_event(client, &event);
73 89
74 wake_up_interruptible(&evdev->wait); 90 wake_up_interruptible(&evdev->wait);
75} 91}
@@ -88,38 +104,142 @@ static int evdev_flush(struct file *file, fl_owner_t id)
88{ 104{
89 struct evdev_client *client = file->private_data; 105 struct evdev_client *client = file->private_data;
90 struct evdev *evdev = client->evdev; 106 struct evdev *evdev = client->evdev;
107 int retval;
108
109 retval = mutex_lock_interruptible(&evdev->mutex);
110 if (retval)
111 return retval;
91 112
92 if (!evdev->exist) 113 if (!evdev->exist)
93 return -ENODEV; 114 retval = -ENODEV;
115 else
116 retval = input_flush_device(&evdev->handle, file);
94 117
95 return input_flush_device(&evdev->handle, file); 118 mutex_unlock(&evdev->mutex);
119 return retval;
96} 120}
97 121
98static void evdev_free(struct device *dev) 122static void evdev_free(struct device *dev)
99{ 123{
100 struct evdev *evdev = container_of(dev, struct evdev, dev); 124 struct evdev *evdev = container_of(dev, struct evdev, dev);
101 125
102 evdev_table[evdev->minor] = NULL;
103 kfree(evdev); 126 kfree(evdev);
104} 127}
105 128
129/*
130 * Grabs an event device (along with underlying input device).
131 * This function is called with evdev->mutex taken.
132 */
133static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
134{
135 int error;
136
137 if (evdev->grab)
138 return -EBUSY;
139
140 error = input_grab_device(&evdev->handle);
141 if (error)
142 return error;
143
144 rcu_assign_pointer(evdev->grab, client);
145 /*
146 * We don't use synchronize_rcu() here because read-side
147 * critical section is protected by a spinlock instead
148 * of rcu_read_lock().
149 */
150 synchronize_sched();
151
152 return 0;
153}
154
155static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
156{
157 if (evdev->grab != client)
158 return -EINVAL;
159
160 rcu_assign_pointer(evdev->grab, NULL);
161 synchronize_sched();
162 input_release_device(&evdev->handle);
163
164 return 0;
165}
166
167static void evdev_attach_client(struct evdev *evdev,
168 struct evdev_client *client)
169{
170 spin_lock(&evdev->client_lock);
171 list_add_tail_rcu(&client->node, &evdev->client_list);
172 spin_unlock(&evdev->client_lock);
173 synchronize_sched();
174}
175
176static void evdev_detach_client(struct evdev *evdev,
177 struct evdev_client *client)
178{
179 spin_lock(&evdev->client_lock);
180 list_del_rcu(&client->node);
181 spin_unlock(&evdev->client_lock);
182 synchronize_sched();
183}
184
185static int evdev_open_device(struct evdev *evdev)
186{
187 int retval;
188
189 retval = mutex_lock_interruptible(&evdev->mutex);
190 if (retval)
191 return retval;
192
193 if (!evdev->exist)
194 retval = -ENODEV;
195 else if (!evdev->open++)
196 retval = input_open_device(&evdev->handle);
197
198 mutex_unlock(&evdev->mutex);
199 return retval;
200}
201
202static void evdev_close_device(struct evdev *evdev)
203{
204 mutex_lock(&evdev->mutex);
205
206 if (evdev->exist && !--evdev->open)
207 input_close_device(&evdev->handle);
208
209 mutex_unlock(&evdev->mutex);
210}
211
212/*
213 * Wake up users waiting for IO so they can disconnect from
214 * dead device.
215 */
216static void evdev_hangup(struct evdev *evdev)
217{
218 struct evdev_client *client;
219
220 spin_lock(&evdev->client_lock);
221 list_for_each_entry(client, &evdev->client_list, node)
222 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
223 spin_unlock(&evdev->client_lock);
224
225 wake_up_interruptible(&evdev->wait);
226}
227
106static int evdev_release(struct inode *inode, struct file *file) 228static int evdev_release(struct inode *inode, struct file *file)
107{ 229{
108 struct evdev_client *client = file->private_data; 230 struct evdev_client *client = file->private_data;
109 struct evdev *evdev = client->evdev; 231 struct evdev *evdev = client->evdev;
110 232
111 if (evdev->grab == client) { 233 mutex_lock(&evdev->mutex);
112 input_release_device(&evdev->handle); 234 if (evdev->grab == client)
113 evdev->grab = NULL; 235 evdev_ungrab(evdev, client);
114 } 236 mutex_unlock(&evdev->mutex);
115 237
116 evdev_fasync(-1, file, 0); 238 evdev_fasync(-1, file, 0);
117 list_del(&client->node); 239 evdev_detach_client(evdev, client);
118 kfree(client); 240 kfree(client);
119 241
120 if (!--evdev->open && evdev->exist) 242 evdev_close_device(evdev);
121 input_close_device(&evdev->handle);
122
123 put_device(&evdev->dev); 243 put_device(&evdev->dev);
124 244
125 return 0; 245 return 0;
@@ -127,41 +247,44 @@ static int evdev_release(struct inode *inode, struct file *file)
127 247
128static int evdev_open(struct inode *inode, struct file *file) 248static int evdev_open(struct inode *inode, struct file *file)
129{ 249{
130 struct evdev_client *client;
131 struct evdev *evdev; 250 struct evdev *evdev;
251 struct evdev_client *client;
132 int i = iminor(inode) - EVDEV_MINOR_BASE; 252 int i = iminor(inode) - EVDEV_MINOR_BASE;
133 int error; 253 int error;
134 254
135 if (i >= EVDEV_MINORS) 255 if (i >= EVDEV_MINORS)
136 return -ENODEV; 256 return -ENODEV;
137 257
258 error = mutex_lock_interruptible(&evdev_table_mutex);
259 if (error)
260 return error;
138 evdev = evdev_table[i]; 261 evdev = evdev_table[i];
262 if (evdev)
263 get_device(&evdev->dev);
264 mutex_unlock(&evdev_table_mutex);
139 265
140 if (!evdev || !evdev->exist) 266 if (!evdev)
141 return -ENODEV; 267 return -ENODEV;
142 268
143 get_device(&evdev->dev);
144
145 client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL); 269 client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
146 if (!client) { 270 if (!client) {
147 error = -ENOMEM; 271 error = -ENOMEM;
148 goto err_put_evdev; 272 goto err_put_evdev;
149 } 273 }
150 274
275 spin_lock_init(&client->buffer_lock);
151 client->evdev = evdev; 276 client->evdev = evdev;
152 list_add_tail(&client->node, &evdev->client_list); 277 evdev_attach_client(evdev, client);
153 278
154 if (!evdev->open++ && evdev->exist) { 279 error = evdev_open_device(evdev);
155 error = input_open_device(&evdev->handle); 280 if (error)
156 if (error) 281 goto err_free_client;
157 goto err_free_client;
158 }
159 282
160 file->private_data = client; 283 file->private_data = client;
161 return 0; 284 return 0;
162 285
163 err_free_client: 286 err_free_client:
164 list_del(&client->node); 287 evdev_detach_client(evdev, client);
165 kfree(client); 288 kfree(client);
166 err_put_evdev: 289 err_put_evdev:
167 put_device(&evdev->dev); 290 put_device(&evdev->dev);
@@ -197,12 +320,14 @@ static inline size_t evdev_event_size(void)
197 sizeof(struct input_event_compat) : sizeof(struct input_event); 320 sizeof(struct input_event_compat) : sizeof(struct input_event);
198} 321}
199 322
200static int evdev_event_from_user(const char __user *buffer, struct input_event *event) 323static int evdev_event_from_user(const char __user *buffer,
324 struct input_event *event)
201{ 325{
202 if (COMPAT_TEST) { 326 if (COMPAT_TEST) {
203 struct input_event_compat compat_event; 327 struct input_event_compat compat_event;
204 328
205 if (copy_from_user(&compat_event, buffer, sizeof(struct input_event_compat))) 329 if (copy_from_user(&compat_event, buffer,
330 sizeof(struct input_event_compat)))
206 return -EFAULT; 331 return -EFAULT;
207 332
208 event->time.tv_sec = compat_event.time.tv_sec; 333 event->time.tv_sec = compat_event.time.tv_sec;
@@ -219,7 +344,8 @@ static int evdev_event_from_user(const char __user *buffer, struct input_event *
219 return 0; 344 return 0;
220} 345}
221 346
222static int evdev_event_to_user(char __user *buffer, const struct input_event *event) 347static int evdev_event_to_user(char __user *buffer,
348 const struct input_event *event)
223{ 349{
224 if (COMPAT_TEST) { 350 if (COMPAT_TEST) {
225 struct input_event_compat compat_event; 351 struct input_event_compat compat_event;
@@ -230,7 +356,8 @@ static int evdev_event_to_user(char __user *buffer, const struct input_event *ev
230 compat_event.code = event->code; 356 compat_event.code = event->code;
231 compat_event.value = event->value; 357 compat_event.value = event->value;
232 358
233 if (copy_to_user(buffer, &compat_event, sizeof(struct input_event_compat))) 359 if (copy_to_user(buffer, &compat_event,
360 sizeof(struct input_event_compat)))
234 return -EFAULT; 361 return -EFAULT;
235 362
236 } else { 363 } else {
@@ -248,7 +375,8 @@ static inline size_t evdev_event_size(void)
248 return sizeof(struct input_event); 375 return sizeof(struct input_event);
249} 376}
250 377
251static int evdev_event_from_user(const char __user *buffer, struct input_event *event) 378static int evdev_event_from_user(const char __user *buffer,
379 struct input_event *event)
252{ 380{
253 if (copy_from_user(event, buffer, sizeof(struct input_event))) 381 if (copy_from_user(event, buffer, sizeof(struct input_event)))
254 return -EFAULT; 382 return -EFAULT;
@@ -256,7 +384,8 @@ static int evdev_event_from_user(const char __user *buffer, struct input_event *
256 return 0; 384 return 0;
257} 385}
258 386
259static int evdev_event_to_user(char __user *buffer, const struct input_event *event) 387static int evdev_event_to_user(char __user *buffer,
388 const struct input_event *event)
260{ 389{
261 if (copy_to_user(buffer, event, sizeof(struct input_event))) 390 if (copy_to_user(buffer, event, sizeof(struct input_event)))
262 return -EFAULT; 391 return -EFAULT;
@@ -266,37 +395,71 @@ static int evdev_event_to_user(char __user *buffer, const struct input_event *ev
266 395
267#endif /* CONFIG_COMPAT */ 396#endif /* CONFIG_COMPAT */
268 397
269static ssize_t evdev_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 398static ssize_t evdev_write(struct file *file, const char __user *buffer,
399 size_t count, loff_t *ppos)
270{ 400{
271 struct evdev_client *client = file->private_data; 401 struct evdev_client *client = file->private_data;
272 struct evdev *evdev = client->evdev; 402 struct evdev *evdev = client->evdev;
273 struct input_event event; 403 struct input_event event;
274 int retval = 0; 404 int retval;
275 405
276 if (!evdev->exist) 406 retval = mutex_lock_interruptible(&evdev->mutex);
277 return -ENODEV; 407 if (retval)
408 return retval;
409
410 if (!evdev->exist) {
411 retval = -ENODEV;
412 goto out;
413 }
278 414
279 while (retval < count) { 415 while (retval < count) {
280 416
281 if (evdev_event_from_user(buffer + retval, &event)) 417 if (evdev_event_from_user(buffer + retval, &event)) {
282 return -EFAULT; 418 retval = -EFAULT;
283 input_inject_event(&evdev->handle, event.type, event.code, event.value); 419 goto out;
420 }
421
422 input_inject_event(&evdev->handle,
423 event.type, event.code, event.value);
284 retval += evdev_event_size(); 424 retval += evdev_event_size();
285 } 425 }
286 426
427 out:
428 mutex_unlock(&evdev->mutex);
287 return retval; 429 return retval;
288} 430}
289 431
290static ssize_t evdev_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) 432static int evdev_fetch_next_event(struct evdev_client *client,
433 struct input_event *event)
434{
435 int have_event;
436
437 spin_lock_irq(&client->buffer_lock);
438
439 have_event = client->head != client->tail;
440 if (have_event) {
441 *event = client->buffer[client->tail++];
442 client->tail &= EVDEV_BUFFER_SIZE - 1;
443 }
444
445 spin_unlock_irq(&client->buffer_lock);
446
447 return have_event;
448}
449
450static ssize_t evdev_read(struct file *file, char __user *buffer,
451 size_t count, loff_t *ppos)
291{ 452{
292 struct evdev_client *client = file->private_data; 453 struct evdev_client *client = file->private_data;
293 struct evdev *evdev = client->evdev; 454 struct evdev *evdev = client->evdev;
455 struct input_event event;
294 int retval; 456 int retval;
295 457
296 if (count < evdev_event_size()) 458 if (count < evdev_event_size())
297 return -EINVAL; 459 return -EINVAL;
298 460
299 if (client->head == client->tail && evdev->exist && (file->f_flags & O_NONBLOCK)) 461 if (client->head == client->tail && evdev->exist &&
462 (file->f_flags & O_NONBLOCK))
300 return -EAGAIN; 463 return -EAGAIN;
301 464
302 retval = wait_event_interruptible(evdev->wait, 465 retval = wait_event_interruptible(evdev->wait,
@@ -307,14 +470,12 @@ static ssize_t evdev_read(struct file *file, char __user *buffer, size_t count,
307 if (!evdev->exist) 470 if (!evdev->exist)
308 return -ENODEV; 471 return -ENODEV;
309 472
310 while (client->head != client->tail && retval + evdev_event_size() <= count) { 473 while (retval + evdev_event_size() <= count &&
311 474 evdev_fetch_next_event(client, &event)) {
312 struct input_event *event = (struct input_event *) client->buffer + client->tail;
313 475
314 if (evdev_event_to_user(buffer + retval, event)) 476 if (evdev_event_to_user(buffer + retval, &event))
315 return -EFAULT; 477 return -EFAULT;
316 478
317 client->tail = (client->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
318 retval += evdev_event_size(); 479 retval += evdev_event_size();
319 } 480 }
320 481
@@ -409,8 +570,8 @@ static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
409 return copy_to_user(p, str, len) ? -EFAULT : len; 570 return copy_to_user(p, str, len) ? -EFAULT : len;
410} 571}
411 572
412static long evdev_ioctl_handler(struct file *file, unsigned int cmd, 573static long evdev_do_ioctl(struct file *file, unsigned int cmd,
413 void __user *p, int compat_mode) 574 void __user *p, int compat_mode)
414{ 575{
415 struct evdev_client *client = file->private_data; 576 struct evdev_client *client = file->private_data;
416 struct evdev *evdev = client->evdev; 577 struct evdev *evdev = client->evdev;
@@ -421,215 +582,289 @@ static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
421 int i, t, u, v; 582 int i, t, u, v;
422 int error; 583 int error;
423 584
424 if (!evdev->exist)
425 return -ENODEV;
426
427 switch (cmd) { 585 switch (cmd) {
428 586
429 case EVIOCGVERSION: 587 case EVIOCGVERSION:
430 return put_user(EV_VERSION, ip); 588 return put_user(EV_VERSION, ip);
431 589
432 case EVIOCGID: 590 case EVIOCGID:
433 if (copy_to_user(p, &dev->id, sizeof(struct input_id))) 591 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
434 return -EFAULT; 592 return -EFAULT;
435 return 0; 593 return 0;
436 594
437 case EVIOCGREP: 595 case EVIOCGREP:
438 if (!test_bit(EV_REP, dev->evbit)) 596 if (!test_bit(EV_REP, dev->evbit))
439 return -ENOSYS; 597 return -ENOSYS;
440 if (put_user(dev->rep[REP_DELAY], ip)) 598 if (put_user(dev->rep[REP_DELAY], ip))
441 return -EFAULT; 599 return -EFAULT;
442 if (put_user(dev->rep[REP_PERIOD], ip + 1)) 600 if (put_user(dev->rep[REP_PERIOD], ip + 1))
443 return -EFAULT; 601 return -EFAULT;
444 return 0; 602 return 0;
445 603
446 case EVIOCSREP: 604 case EVIOCSREP:
447 if (!test_bit(EV_REP, dev->evbit)) 605 if (!test_bit(EV_REP, dev->evbit))
448 return -ENOSYS; 606 return -ENOSYS;
449 if (get_user(u, ip)) 607 if (get_user(u, ip))
450 return -EFAULT; 608 return -EFAULT;
451 if (get_user(v, ip + 1)) 609 if (get_user(v, ip + 1))
452 return -EFAULT; 610 return -EFAULT;
453 611
454 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u); 612 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
455 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v); 613 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
456 614
457 return 0; 615 return 0;
458 616
459 case EVIOCGKEYCODE: 617 case EVIOCGKEYCODE:
460 if (get_user(t, ip)) 618 if (get_user(t, ip))
461 return -EFAULT; 619 return -EFAULT;
462 620
463 error = dev->getkeycode(dev, t, &v); 621 error = dev->getkeycode(dev, t, &v);
464 if (error) 622 if (error)
465 return error; 623 return error;
466 624
467 if (put_user(v, ip + 1)) 625 if (put_user(v, ip + 1))
468 return -EFAULT; 626 return -EFAULT;
469 627
470 return 0; 628 return 0;
471 629
472 case EVIOCSKEYCODE: 630 case EVIOCSKEYCODE:
473 if (get_user(t, ip) || get_user(v, ip + 1)) 631 if (get_user(t, ip) || get_user(v, ip + 1))
474 return -EFAULT; 632 return -EFAULT;
475 633
476 return dev->setkeycode(dev, t, v); 634 return dev->setkeycode(dev, t, v);
477 635
478 case EVIOCSFF: 636 case EVIOCSFF:
479 if (copy_from_user(&effect, p, sizeof(effect))) 637 if (copy_from_user(&effect, p, sizeof(effect)))
480 return -EFAULT; 638 return -EFAULT;
481 639
482 error = input_ff_upload(dev, &effect, file); 640 error = input_ff_upload(dev, &effect, file);
483 641
484 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) 642 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
485 return -EFAULT; 643 return -EFAULT;
486 644
487 return error; 645 return error;
488 646
489 case EVIOCRMFF: 647 case EVIOCRMFF:
490 return input_ff_erase(dev, (int)(unsigned long) p, file); 648 return input_ff_erase(dev, (int)(unsigned long) p, file);
491 649
492 case EVIOCGEFFECTS: 650 case EVIOCGEFFECTS:
493 i = test_bit(EV_FF, dev->evbit) ? dev->ff->max_effects : 0; 651 i = test_bit(EV_FF, dev->evbit) ?
494 if (put_user(i, ip)) 652 dev->ff->max_effects : 0;
495 return -EFAULT; 653 if (put_user(i, ip))
496 return 0; 654 return -EFAULT;
497 655 return 0;
498 case EVIOCGRAB: 656
499 if (p) { 657 case EVIOCGRAB:
500 if (evdev->grab) 658 if (p)
501 return -EBUSY; 659 return evdev_grab(evdev, client);
502 if (input_grab_device(&evdev->handle)) 660 else
503 return -EBUSY; 661 return evdev_ungrab(evdev, client);
504 evdev->grab = client;
505 return 0;
506 } else {
507 if (evdev->grab != client)
508 return -EINVAL;
509 input_release_device(&evdev->handle);
510 evdev->grab = NULL;
511 return 0;
512 }
513 662
514 default: 663 default:
515 664
516 if (_IOC_TYPE(cmd) != 'E') 665 if (_IOC_TYPE(cmd) != 'E')
517 return -EINVAL; 666 return -EINVAL;
518 667
519 if (_IOC_DIR(cmd) == _IOC_READ) { 668 if (_IOC_DIR(cmd) == _IOC_READ) {
520 669
521 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) { 670 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) {
522 671
523 unsigned long *bits; 672 unsigned long *bits;
524 int len; 673 int len;
525 674
526 switch (_IOC_NR(cmd) & EV_MAX) { 675 switch (_IOC_NR(cmd) & EV_MAX) {
527 case 0: bits = dev->evbit; len = EV_MAX; break;
528 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
529 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
530 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
531 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
532 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
533 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
534 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
535 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
536 default: return -EINVAL;
537 }
538 return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
539 }
540 676
541 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) 677 case 0: bits = dev->evbit; len = EV_MAX; break;
542 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd), 678 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
543 p, compat_mode); 679 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
680 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
681 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
682 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
683 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
684 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
685 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
686 default: return -EINVAL;
687 }
688 return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
689 }
544 690
545 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) 691 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
546 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd), 692 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
547 p, compat_mode); 693 p, compat_mode);
548 694
549 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) 695 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
550 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd), 696 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
551 p, compat_mode); 697 p, compat_mode);
552 698
553 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0))) 699 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
554 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd), 700 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
555 p, compat_mode); 701 p, compat_mode);
556 702
557 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) 703 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
558 return str_to_user(dev->name, _IOC_SIZE(cmd), p); 704 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
705 p, compat_mode);
559 706
560 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) 707 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
561 return str_to_user(dev->phys, _IOC_SIZE(cmd), p); 708 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
562 709
563 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) 710 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
564 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p); 711 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
565 712
566 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) { 713 if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
714 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
567 715
568 t = _IOC_NR(cmd) & ABS_MAX; 716 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
569 717
570 abs.value = dev->abs[t]; 718 t = _IOC_NR(cmd) & ABS_MAX;
571 abs.minimum = dev->absmin[t];
572 abs.maximum = dev->absmax[t];
573 abs.fuzz = dev->absfuzz[t];
574 abs.flat = dev->absflat[t];
575 719
576 if (copy_to_user(p, &abs, sizeof(struct input_absinfo))) 720 abs.value = dev->abs[t];
577 return -EFAULT; 721 abs.minimum = dev->absmin[t];
722 abs.maximum = dev->absmax[t];
723 abs.fuzz = dev->absfuzz[t];
724 abs.flat = dev->absflat[t];
578 725
579 return 0; 726 if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
580 } 727 return -EFAULT;
581 728
729 return 0;
582 } 730 }
583 731
584 if (_IOC_DIR(cmd) == _IOC_WRITE) { 732 }
733
734 if (_IOC_DIR(cmd) == _IOC_WRITE) {
585 735
586 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) { 736 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
587 737
588 t = _IOC_NR(cmd) & ABS_MAX; 738 t = _IOC_NR(cmd) & ABS_MAX;
589 739
590 if (copy_from_user(&abs, p, sizeof(struct input_absinfo))) 740 if (copy_from_user(&abs, p,
591 return -EFAULT; 741 sizeof(struct input_absinfo)))
742 return -EFAULT;
592 743
593 dev->abs[t] = abs.value; 744 /*
594 dev->absmin[t] = abs.minimum; 745 * Take event lock to ensure that we are not
595 dev->absmax[t] = abs.maximum; 746 * changing device parameters in the middle
596 dev->absfuzz[t] = abs.fuzz; 747 * of event.
597 dev->absflat[t] = abs.flat; 748 */
749 spin_lock_irq(&dev->event_lock);
598 750
599 return 0; 751 dev->abs[t] = abs.value;
600 } 752 dev->absmin[t] = abs.minimum;
753 dev->absmax[t] = abs.maximum;
754 dev->absfuzz[t] = abs.fuzz;
755 dev->absflat[t] = abs.flat;
756
757 spin_unlock_irq(&dev->event_lock);
758
759 return 0;
601 } 760 }
761 }
602 } 762 }
603 return -EINVAL; 763 return -EINVAL;
604} 764}
605 765
766static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
767 void __user *p, int compat_mode)
768{
769 struct evdev_client *client = file->private_data;
770 struct evdev *evdev = client->evdev;
771 int retval;
772
773 retval = mutex_lock_interruptible(&evdev->mutex);
774 if (retval)
775 return retval;
776
777 if (!evdev->exist) {
778 retval = -ENODEV;
779 goto out;
780 }
781
782 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
783
784 out:
785 mutex_unlock(&evdev->mutex);
786 return retval;
787}
788
606static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 789static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
607{ 790{
608 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0); 791 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
609} 792}
610 793
611#ifdef CONFIG_COMPAT 794#ifdef CONFIG_COMPAT
612static long evdev_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg) 795static long evdev_ioctl_compat(struct file *file,
796 unsigned int cmd, unsigned long arg)
613{ 797{
614 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1); 798 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
615} 799}
616#endif 800#endif
617 801
618static const struct file_operations evdev_fops = { 802static const struct file_operations evdev_fops = {
619 .owner = THIS_MODULE, 803 .owner = THIS_MODULE,
620 .read = evdev_read, 804 .read = evdev_read,
621 .write = evdev_write, 805 .write = evdev_write,
622 .poll = evdev_poll, 806 .poll = evdev_poll,
623 .open = evdev_open, 807 .open = evdev_open,
624 .release = evdev_release, 808 .release = evdev_release,
625 .unlocked_ioctl = evdev_ioctl, 809 .unlocked_ioctl = evdev_ioctl,
626#ifdef CONFIG_COMPAT 810#ifdef CONFIG_COMPAT
627 .compat_ioctl = evdev_ioctl_compat, 811 .compat_ioctl = evdev_ioctl_compat,
628#endif 812#endif
629 .fasync = evdev_fasync, 813 .fasync = evdev_fasync,
630 .flush = evdev_flush 814 .flush = evdev_flush
631}; 815};
632 816
817static int evdev_install_chrdev(struct evdev *evdev)
818{
819 /*
820 * No need to do any locking here as calls to connect and
821 * disconnect are serialized by the input core
822 */
823 evdev_table[evdev->minor] = evdev;
824 return 0;
825}
826
827static void evdev_remove_chrdev(struct evdev *evdev)
828{
829 /*
830 * Lock evdev table to prevent race with evdev_open()
831 */
832 mutex_lock(&evdev_table_mutex);
833 evdev_table[evdev->minor] = NULL;
834 mutex_unlock(&evdev_table_mutex);
835}
836
837/*
838 * Mark device non-existent. This disables writes, ioctls and
839 * prevents new users from opening the device. Already posted
840 * blocking reads will stay, however new ones will fail.
841 */
842static void evdev_mark_dead(struct evdev *evdev)
843{
844 mutex_lock(&evdev->mutex);
845 evdev->exist = 0;
846 mutex_unlock(&evdev->mutex);
847}
848
849static void evdev_cleanup(struct evdev *evdev)
850{
851 struct input_handle *handle = &evdev->handle;
852
853 evdev_mark_dead(evdev);
854 evdev_hangup(evdev);
855 evdev_remove_chrdev(evdev);
856
857 /* evdev is marked dead so no one else accesses evdev->open */
858 if (evdev->open) {
859 input_flush_device(handle, NULL);
860 input_close_device(handle);
861 }
862}
863
864/*
865 * Create new evdev device. Note that input core serializes calls
866 * to connect and disconnect so we don't need to lock evdev_table here.
867 */
633static int evdev_connect(struct input_handler *handler, struct input_dev *dev, 868static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
634 const struct input_device_id *id) 869 const struct input_device_id *id)
635{ 870{
@@ -637,7 +872,10 @@ static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
637 int minor; 872 int minor;
638 int error; 873 int error;
639 874
640 for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++); 875 for (minor = 0; minor < EVDEV_MINORS; minor++)
876 if (!evdev_table[minor])
877 break;
878
641 if (minor == EVDEV_MINORS) { 879 if (minor == EVDEV_MINORS) {
642 printk(KERN_ERR "evdev: no more free evdev devices\n"); 880 printk(KERN_ERR "evdev: no more free evdev devices\n");
643 return -ENFILE; 881 return -ENFILE;
@@ -648,38 +886,44 @@ static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
648 return -ENOMEM; 886 return -ENOMEM;
649 887
650 INIT_LIST_HEAD(&evdev->client_list); 888 INIT_LIST_HEAD(&evdev->client_list);
889 spin_lock_init(&evdev->client_lock);
890 mutex_init(&evdev->mutex);
651 init_waitqueue_head(&evdev->wait); 891 init_waitqueue_head(&evdev->wait);
652 892
893 snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
653 evdev->exist = 1; 894 evdev->exist = 1;
654 evdev->minor = minor; 895 evdev->minor = minor;
896
655 evdev->handle.dev = dev; 897 evdev->handle.dev = dev;
656 evdev->handle.name = evdev->name; 898 evdev->handle.name = evdev->name;
657 evdev->handle.handler = handler; 899 evdev->handle.handler = handler;
658 evdev->handle.private = evdev; 900 evdev->handle.private = evdev;
659 snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
660 901
661 snprintf(evdev->dev.bus_id, sizeof(evdev->dev.bus_id), 902 strlcpy(evdev->dev.bus_id, evdev->name, sizeof(evdev->dev.bus_id));
662 "event%d", minor); 903 evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
663 evdev->dev.class = &input_class; 904 evdev->dev.class = &input_class;
664 evdev->dev.parent = &dev->dev; 905 evdev->dev.parent = &dev->dev;
665 evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
666 evdev->dev.release = evdev_free; 906 evdev->dev.release = evdev_free;
667 device_initialize(&evdev->dev); 907 device_initialize(&evdev->dev);
668 908
669 evdev_table[minor] = evdev; 909 error = input_register_handle(&evdev->handle);
670
671 error = device_add(&evdev->dev);
672 if (error) 910 if (error)
673 goto err_free_evdev; 911 goto err_free_evdev;
674 912
675 error = input_register_handle(&evdev->handle); 913 error = evdev_install_chrdev(evdev);
914 if (error)
915 goto err_unregister_handle;
916
917 error = device_add(&evdev->dev);
676 if (error) 918 if (error)
677 goto err_delete_evdev; 919 goto err_cleanup_evdev;
678 920
679 return 0; 921 return 0;
680 922
681 err_delete_evdev: 923 err_cleanup_evdev:
682 device_del(&evdev->dev); 924 evdev_cleanup(evdev);
925 err_unregister_handle:
926 input_unregister_handle(&evdev->handle);
683 err_free_evdev: 927 err_free_evdev:
684 put_device(&evdev->dev); 928 put_device(&evdev->dev);
685 return error; 929 return error;
@@ -688,21 +932,10 @@ static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
688static void evdev_disconnect(struct input_handle *handle) 932static void evdev_disconnect(struct input_handle *handle)
689{ 933{
690 struct evdev *evdev = handle->private; 934 struct evdev *evdev = handle->private;
691 struct evdev_client *client;
692 935
693 input_unregister_handle(handle);
694 device_del(&evdev->dev); 936 device_del(&evdev->dev);
695 937 evdev_cleanup(evdev);
696 evdev->exist = 0; 938 input_unregister_handle(handle);
697
698 if (evdev->open) {
699 input_flush_device(handle, NULL);
700 input_close_device(handle);
701 list_for_each_entry(client, &evdev->client_list, node)
702 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
703 wake_up_interruptible(&evdev->wait);
704 }
705
706 put_device(&evdev->dev); 939 put_device(&evdev->dev);
707} 940}
708 941
@@ -714,13 +947,13 @@ static const struct input_device_id evdev_ids[] = {
714MODULE_DEVICE_TABLE(input, evdev_ids); 947MODULE_DEVICE_TABLE(input, evdev_ids);
715 948
716static struct input_handler evdev_handler = { 949static struct input_handler evdev_handler = {
717 .event = evdev_event, 950 .event = evdev_event,
718 .connect = evdev_connect, 951 .connect = evdev_connect,
719 .disconnect = evdev_disconnect, 952 .disconnect = evdev_disconnect,
720 .fops = &evdev_fops, 953 .fops = &evdev_fops,
721 .minor = EVDEV_MINOR_BASE, 954 .minor = EVDEV_MINOR_BASE,
722 .name = "evdev", 955 .name = "evdev",
723 .id_table = evdev_ids, 956 .id_table = evdev_ids,
724}; 957};
725 958
726static int __init evdev_init(void) 959static int __init evdev_init(void)
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-14 10:06:33 -0500