1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Event char devices, giving access to raw input device events. |
4 | * |
5 | * Copyright (c) 1999-2002 Vojtech Pavlik |
6 | */ |
7 | |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | |
10 | #define EVDEV_MINOR_BASE 64 |
11 | #define EVDEV_MINORS 32 |
12 | #define EVDEV_MIN_BUFFER_SIZE 64U |
13 | #define EVDEV_BUF_PACKETS 8 |
14 | |
15 | #include <linux/poll.h> |
16 | #include <linux/sched.h> |
17 | #include <linux/slab.h> |
18 | #include <linux/vmalloc.h> |
19 | #include <linux/mm.h> |
20 | #include <linux/module.h> |
21 | #include <linux/init.h> |
22 | #include <linux/input/mt.h> |
23 | #include <linux/major.h> |
24 | #include <linux/device.h> |
25 | #include <linux/cdev.h> |
26 | #include "input-compat.h" |
27 | |
28 | struct evdev { |
29 | int open; |
30 | struct input_handle handle; |
31 | struct evdev_client __rcu *grab; |
32 | struct list_head client_list; |
33 | spinlock_t client_lock; /* protects client_list */ |
34 | struct mutex mutex; |
35 | struct device dev; |
36 | struct cdev cdev; |
37 | bool exist; |
38 | }; |
39 | |
40 | struct evdev_client { |
41 | unsigned int head; |
42 | unsigned int tail; |
43 | unsigned int packet_head; /* [future] position of the first element of next packet */ |
44 | spinlock_t buffer_lock; /* protects access to buffer, head and tail */ |
45 | wait_queue_head_t wait; |
46 | struct fasync_struct *fasync; |
47 | struct evdev *evdev; |
48 | struct list_head node; |
49 | enum input_clock_type clk_type; |
50 | bool revoked; |
51 | unsigned long *evmasks[EV_CNT]; |
52 | unsigned int bufsize; |
53 | struct input_event buffer[]; |
54 | }; |
55 | |
56 | static size_t evdev_get_mask_cnt(unsigned int type) |
57 | { |
58 | static const size_t counts[EV_CNT] = { |
59 | /* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */ |
60 | [EV_SYN] = EV_CNT, |
61 | [EV_KEY] = KEY_CNT, |
62 | [EV_REL] = REL_CNT, |
63 | [EV_ABS] = ABS_CNT, |
64 | [EV_MSC] = MSC_CNT, |
65 | [EV_SW] = SW_CNT, |
66 | [EV_LED] = LED_CNT, |
67 | [EV_SND] = SND_CNT, |
68 | [EV_FF] = FF_CNT, |
69 | }; |
70 | |
71 | return (type < EV_CNT) ? counts[type] : 0; |
72 | } |
73 | |
74 | /* requires the buffer lock to be held */ |
75 | static bool __evdev_is_filtered(struct evdev_client *client, |
76 | unsigned int type, |
77 | unsigned int code) |
78 | { |
79 | unsigned long *mask; |
80 | size_t cnt; |
81 | |
82 | /* EV_SYN and unknown codes are never filtered */ |
83 | if (type == EV_SYN || type >= EV_CNT) |
84 | return false; |
85 | |
86 | /* first test whether the type is filtered */ |
87 | mask = client->evmasks[0]; |
88 | if (mask && !test_bit(type, mask)) |
89 | return true; |
90 | |
91 | /* unknown values are never filtered */ |
92 | cnt = evdev_get_mask_cnt(type); |
93 | if (!cnt || code >= cnt) |
94 | return false; |
95 | |
96 | mask = client->evmasks[type]; |
97 | return mask && !test_bit(code, mask); |
98 | } |
99 | |
100 | /* flush queued events of type @type, caller must hold client->buffer_lock */ |
101 | static void __evdev_flush_queue(struct evdev_client *client, unsigned int type) |
102 | { |
103 | unsigned int i, head, num; |
104 | unsigned int mask = client->bufsize - 1; |
105 | bool is_report; |
106 | struct input_event *ev; |
107 | |
108 | BUG_ON(type == EV_SYN); |
109 | |
110 | head = client->tail; |
111 | client->packet_head = client->tail; |
112 | |
113 | /* init to 1 so a leading SYN_REPORT will not be dropped */ |
114 | num = 1; |
115 | |
116 | for (i = client->tail; i != client->head; i = (i + 1) & mask) { |
117 | ev = &client->buffer[i]; |
118 | is_report = ev->type == EV_SYN && ev->code == SYN_REPORT; |
119 | |
120 | if (ev->type == type) { |
121 | /* drop matched entry */ |
122 | continue; |
123 | } else if (is_report && !num) { |
124 | /* drop empty SYN_REPORT groups */ |
125 | continue; |
126 | } else if (head != i) { |
127 | /* move entry to fill the gap */ |
128 | client->buffer[head] = *ev; |
129 | } |
130 | |
131 | num++; |
132 | head = (head + 1) & mask; |
133 | |
134 | if (is_report) { |
135 | num = 0; |
136 | client->packet_head = head; |
137 | } |
138 | } |
139 | |
140 | client->head = head; |
141 | } |
142 | |
143 | static void __evdev_queue_syn_dropped(struct evdev_client *client) |
144 | { |
145 | ktime_t *ev_time = input_get_timestamp(dev: client->evdev->handle.dev); |
146 | struct timespec64 ts = ktime_to_timespec64(ev_time[client->clk_type]); |
147 | struct input_event ev; |
148 | |
149 | ev.input_event_sec = ts.tv_sec; |
150 | ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC; |
151 | ev.type = EV_SYN; |
152 | ev.code = SYN_DROPPED; |
153 | ev.value = 0; |
154 | |
155 | client->buffer[client->head++] = ev; |
156 | client->head &= client->bufsize - 1; |
157 | |
158 | if (unlikely(client->head == client->tail)) { |
159 | /* drop queue but keep our SYN_DROPPED event */ |
160 | client->tail = (client->head - 1) & (client->bufsize - 1); |
161 | client->packet_head = client->tail; |
162 | } |
163 | } |
164 | |
165 | static void evdev_queue_syn_dropped(struct evdev_client *client) |
166 | { |
167 | unsigned long flags; |
168 | |
169 | spin_lock_irqsave(&client->buffer_lock, flags); |
170 | __evdev_queue_syn_dropped(client); |
171 | spin_unlock_irqrestore(lock: &client->buffer_lock, flags); |
172 | } |
173 | |
174 | static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid) |
175 | { |
176 | unsigned long flags; |
177 | enum input_clock_type clk_type; |
178 | |
179 | switch (clkid) { |
180 | |
181 | case CLOCK_REALTIME: |
182 | clk_type = INPUT_CLK_REAL; |
183 | break; |
184 | case CLOCK_MONOTONIC: |
185 | clk_type = INPUT_CLK_MONO; |
186 | break; |
187 | case CLOCK_BOOTTIME: |
188 | clk_type = INPUT_CLK_BOOT; |
189 | break; |
190 | default: |
191 | return -EINVAL; |
192 | } |
193 | |
194 | if (client->clk_type != clk_type) { |
195 | client->clk_type = clk_type; |
196 | |
197 | /* |
198 | * Flush pending events and queue SYN_DROPPED event, |
199 | * but only if the queue is not empty. |
200 | */ |
201 | spin_lock_irqsave(&client->buffer_lock, flags); |
202 | |
203 | if (client->head != client->tail) { |
204 | client->packet_head = client->head = client->tail; |
205 | __evdev_queue_syn_dropped(client); |
206 | } |
207 | |
208 | spin_unlock_irqrestore(lock: &client->buffer_lock, flags); |
209 | } |
210 | |
211 | return 0; |
212 | } |
213 | |
214 | static void __pass_event(struct evdev_client *client, |
215 | const struct input_event *event) |
216 | { |
217 | client->buffer[client->head++] = *event; |
218 | client->head &= client->bufsize - 1; |
219 | |
220 | if (unlikely(client->head == client->tail)) { |
221 | /* |
222 | * This effectively "drops" all unconsumed events, leaving |
223 | * EV_SYN/SYN_DROPPED plus the newest event in the queue. |
224 | */ |
225 | client->tail = (client->head - 2) & (client->bufsize - 1); |
226 | |
227 | client->buffer[client->tail] = (struct input_event) { |
228 | .input_event_sec = event->input_event_sec, |
229 | .input_event_usec = event->input_event_usec, |
230 | .type = EV_SYN, |
231 | .code = SYN_DROPPED, |
232 | .value = 0, |
233 | }; |
234 | |
235 | client->packet_head = client->tail; |
236 | } |
237 | |
238 | if (event->type == EV_SYN && event->code == SYN_REPORT) { |
239 | client->packet_head = client->head; |
240 | kill_fasync(&client->fasync, SIGIO, POLL_IN); |
241 | } |
242 | } |
243 | |
244 | static void evdev_pass_values(struct evdev_client *client, |
245 | const struct input_value *vals, unsigned int count, |
246 | ktime_t *ev_time) |
247 | { |
248 | const struct input_value *v; |
249 | struct input_event event; |
250 | struct timespec64 ts; |
251 | bool wakeup = false; |
252 | |
253 | if (client->revoked) |
254 | return; |
255 | |
256 | ts = ktime_to_timespec64(ev_time[client->clk_type]); |
257 | event.input_event_sec = ts.tv_sec; |
258 | event.input_event_usec = ts.tv_nsec / NSEC_PER_USEC; |
259 | |
260 | /* Interrupts are disabled, just acquire the lock. */ |
261 | spin_lock(lock: &client->buffer_lock); |
262 | |
263 | for (v = vals; v != vals + count; v++) { |
264 | if (__evdev_is_filtered(client, type: v->type, code: v->code)) |
265 | continue; |
266 | |
267 | if (v->type == EV_SYN && v->code == SYN_REPORT) { |
268 | /* drop empty SYN_REPORT */ |
269 | if (client->packet_head == client->head) |
270 | continue; |
271 | |
272 | wakeup = true; |
273 | } |
274 | |
275 | event.type = v->type; |
276 | event.code = v->code; |
277 | event.value = v->value; |
278 | __pass_event(client, event: &event); |
279 | } |
280 | |
281 | spin_unlock(lock: &client->buffer_lock); |
282 | |
283 | if (wakeup) |
284 | wake_up_interruptible_poll(&client->wait, |
285 | EPOLLIN | EPOLLOUT | EPOLLRDNORM | EPOLLWRNORM); |
286 | } |
287 | |
288 | /* |
289 | * Pass incoming events to all connected clients. |
290 | */ |
291 | static void evdev_events(struct input_handle *handle, |
292 | const struct input_value *vals, unsigned int count) |
293 | { |
294 | struct evdev *evdev = handle->private; |
295 | struct evdev_client *client; |
296 | ktime_t *ev_time = input_get_timestamp(dev: handle->dev); |
297 | |
298 | rcu_read_lock(); |
299 | |
300 | client = rcu_dereference(evdev->grab); |
301 | |
302 | if (client) |
303 | evdev_pass_values(client, vals, count, ev_time); |
304 | else |
305 | list_for_each_entry_rcu(client, &evdev->client_list, node) |
306 | evdev_pass_values(client, vals, count, ev_time); |
307 | |
308 | rcu_read_unlock(); |
309 | } |
310 | |
311 | /* |
312 | * Pass incoming event to all connected clients. |
313 | */ |
314 | static void evdev_event(struct input_handle *handle, |
315 | unsigned int type, unsigned int code, int value) |
316 | { |
317 | struct input_value vals[] = { { type, code, value } }; |
318 | |
319 | evdev_events(handle, vals, count: 1); |
320 | } |
321 | |
322 | static int evdev_fasync(int fd, struct file *file, int on) |
323 | { |
324 | struct evdev_client *client = file->private_data; |
325 | |
326 | return fasync_helper(fd, file, on, &client->fasync); |
327 | } |
328 | |
329 | static void evdev_free(struct device *dev) |
330 | { |
331 | struct evdev *evdev = container_of(dev, struct evdev, dev); |
332 | |
333 | input_put_device(dev: evdev->handle.dev); |
334 | kfree(objp: evdev); |
335 | } |
336 | |
337 | /* |
338 | * Grabs an event device (along with underlying input device). |
339 | * This function is called with evdev->mutex taken. |
340 | */ |
341 | static int evdev_grab(struct evdev *evdev, struct evdev_client *client) |
342 | { |
343 | int error; |
344 | |
345 | if (evdev->grab) |
346 | return -EBUSY; |
347 | |
348 | error = input_grab_device(&evdev->handle); |
349 | if (error) |
350 | return error; |
351 | |
352 | rcu_assign_pointer(evdev->grab, client); |
353 | |
354 | return 0; |
355 | } |
356 | |
357 | static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client) |
358 | { |
359 | struct evdev_client *grab = rcu_dereference_protected(evdev->grab, |
360 | lockdep_is_held(&evdev->mutex)); |
361 | |
362 | if (grab != client) |
363 | return -EINVAL; |
364 | |
365 | rcu_assign_pointer(evdev->grab, NULL); |
366 | synchronize_rcu(); |
367 | input_release_device(&evdev->handle); |
368 | |
369 | return 0; |
370 | } |
371 | |
372 | static void evdev_attach_client(struct evdev *evdev, |
373 | struct evdev_client *client) |
374 | { |
375 | spin_lock(lock: &evdev->client_lock); |
376 | list_add_tail_rcu(new: &client->node, head: &evdev->client_list); |
377 | spin_unlock(lock: &evdev->client_lock); |
378 | } |
379 | |
380 | static void evdev_detach_client(struct evdev *evdev, |
381 | struct evdev_client *client) |
382 | { |
383 | spin_lock(lock: &evdev->client_lock); |
384 | list_del_rcu(entry: &client->node); |
385 | spin_unlock(lock: &evdev->client_lock); |
386 | synchronize_rcu(); |
387 | } |
388 | |
389 | static int evdev_open_device(struct evdev *evdev) |
390 | { |
391 | int retval; |
392 | |
393 | retval = mutex_lock_interruptible(&evdev->mutex); |
394 | if (retval) |
395 | return retval; |
396 | |
397 | if (!evdev->exist) |
398 | retval = -ENODEV; |
399 | else if (!evdev->open++) { |
400 | retval = input_open_device(&evdev->handle); |
401 | if (retval) |
402 | evdev->open--; |
403 | } |
404 | |
405 | mutex_unlock(lock: &evdev->mutex); |
406 | return retval; |
407 | } |
408 | |
409 | static void evdev_close_device(struct evdev *evdev) |
410 | { |
411 | mutex_lock(&evdev->mutex); |
412 | |
413 | if (evdev->exist && !--evdev->open) |
414 | input_close_device(&evdev->handle); |
415 | |
416 | mutex_unlock(lock: &evdev->mutex); |
417 | } |
418 | |
419 | /* |
420 | * Wake up users waiting for IO so they can disconnect from |
421 | * dead device. |
422 | */ |
423 | static void evdev_hangup(struct evdev *evdev) |
424 | { |
425 | struct evdev_client *client; |
426 | |
427 | spin_lock(lock: &evdev->client_lock); |
428 | list_for_each_entry(client, &evdev->client_list, node) { |
429 | kill_fasync(&client->fasync, SIGIO, POLL_HUP); |
430 | wake_up_interruptible_poll(&client->wait, EPOLLHUP | EPOLLERR); |
431 | } |
432 | spin_unlock(lock: &evdev->client_lock); |
433 | } |
434 | |
435 | static int evdev_release(struct inode *inode, struct file *file) |
436 | { |
437 | struct evdev_client *client = file->private_data; |
438 | struct evdev *evdev = client->evdev; |
439 | unsigned int i; |
440 | |
441 | mutex_lock(&evdev->mutex); |
442 | |
443 | if (evdev->exist && !client->revoked) |
444 | input_flush_device(handle: &evdev->handle, file); |
445 | |
446 | evdev_ungrab(evdev, client); |
447 | mutex_unlock(lock: &evdev->mutex); |
448 | |
449 | evdev_detach_client(evdev, client); |
450 | |
451 | for (i = 0; i < EV_CNT; ++i) |
452 | bitmap_free(bitmap: client->evmasks[i]); |
453 | |
454 | kvfree(addr: client); |
455 | |
456 | evdev_close_device(evdev); |
457 | |
458 | return 0; |
459 | } |
460 | |
461 | static unsigned int evdev_compute_buffer_size(struct input_dev *dev) |
462 | { |
463 | unsigned int n_events = |
464 | max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS, |
465 | EVDEV_MIN_BUFFER_SIZE); |
466 | |
467 | return roundup_pow_of_two(n_events); |
468 | } |
469 | |
470 | static int evdev_open(struct inode *inode, struct file *file) |
471 | { |
472 | struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev); |
473 | unsigned int bufsize = evdev_compute_buffer_size(dev: evdev->handle.dev); |
474 | struct evdev_client *client; |
475 | int error; |
476 | |
477 | client = kvzalloc(struct_size(client, buffer, bufsize), GFP_KERNEL); |
478 | if (!client) |
479 | return -ENOMEM; |
480 | |
481 | init_waitqueue_head(&client->wait); |
482 | client->bufsize = bufsize; |
483 | spin_lock_init(&client->buffer_lock); |
484 | client->evdev = evdev; |
485 | evdev_attach_client(evdev, client); |
486 | |
487 | error = evdev_open_device(evdev); |
488 | if (error) |
489 | goto err_free_client; |
490 | |
491 | file->private_data = client; |
492 | stream_open(inode, filp: file); |
493 | |
494 | return 0; |
495 | |
496 | err_free_client: |
497 | evdev_detach_client(evdev, client); |
498 | kvfree(addr: client); |
499 | return error; |
500 | } |
501 | |
502 | static ssize_t evdev_write(struct file *file, const char __user *buffer, |
503 | size_t count, loff_t *ppos) |
504 | { |
505 | struct evdev_client *client = file->private_data; |
506 | struct evdev *evdev = client->evdev; |
507 | struct input_event event; |
508 | int retval = 0; |
509 | |
510 | if (count != 0 && count < input_event_size()) |
511 | return -EINVAL; |
512 | |
513 | retval = mutex_lock_interruptible(&evdev->mutex); |
514 | if (retval) |
515 | return retval; |
516 | |
517 | if (!evdev->exist || client->revoked) { |
518 | retval = -ENODEV; |
519 | goto out; |
520 | } |
521 | |
522 | while (retval + input_event_size() <= count) { |
523 | |
524 | if (input_event_from_user(buffer: buffer + retval, event: &event)) { |
525 | retval = -EFAULT; |
526 | goto out; |
527 | } |
528 | retval += input_event_size(); |
529 | |
530 | input_inject_event(handle: &evdev->handle, |
531 | type: event.type, code: event.code, value: event.value); |
532 | cond_resched(); |
533 | } |
534 | |
535 | out: |
536 | mutex_unlock(lock: &evdev->mutex); |
537 | return retval; |
538 | } |
539 | |
540 | static int evdev_fetch_next_event(struct evdev_client *client, |
541 | struct input_event *event) |
542 | { |
543 | int have_event; |
544 | |
545 | spin_lock_irq(lock: &client->buffer_lock); |
546 | |
547 | have_event = client->packet_head != client->tail; |
548 | if (have_event) { |
549 | *event = client->buffer[client->tail++]; |
550 | client->tail &= client->bufsize - 1; |
551 | } |
552 | |
553 | spin_unlock_irq(lock: &client->buffer_lock); |
554 | |
555 | return have_event; |
556 | } |
557 | |
558 | static ssize_t evdev_read(struct file *file, char __user *buffer, |
559 | size_t count, loff_t *ppos) |
560 | { |
561 | struct evdev_client *client = file->private_data; |
562 | struct evdev *evdev = client->evdev; |
563 | struct input_event event; |
564 | size_t read = 0; |
565 | int error; |
566 | |
567 | if (count != 0 && count < input_event_size()) |
568 | return -EINVAL; |
569 | |
570 | for (;;) { |
571 | if (!evdev->exist || client->revoked) |
572 | return -ENODEV; |
573 | |
574 | if (client->packet_head == client->tail && |
575 | (file->f_flags & O_NONBLOCK)) |
576 | return -EAGAIN; |
577 | |
578 | /* |
579 | * count == 0 is special - no IO is done but we check |
580 | * for error conditions (see above). |
581 | */ |
582 | if (count == 0) |
583 | break; |
584 | |
585 | while (read + input_event_size() <= count && |
586 | evdev_fetch_next_event(client, event: &event)) { |
587 | |
588 | if (input_event_to_user(buffer: buffer + read, event: &event)) |
589 | return -EFAULT; |
590 | |
591 | read += input_event_size(); |
592 | } |
593 | |
594 | if (read) |
595 | break; |
596 | |
597 | if (!(file->f_flags & O_NONBLOCK)) { |
598 | error = wait_event_interruptible(client->wait, |
599 | client->packet_head != client->tail || |
600 | !evdev->exist || client->revoked); |
601 | if (error) |
602 | return error; |
603 | } |
604 | } |
605 | |
606 | return read; |
607 | } |
608 | |
609 | /* No kernel lock - fine */ |
610 | static __poll_t evdev_poll(struct file *file, poll_table *wait) |
611 | { |
612 | struct evdev_client *client = file->private_data; |
613 | struct evdev *evdev = client->evdev; |
614 | __poll_t mask; |
615 | |
616 | poll_wait(filp: file, wait_address: &client->wait, p: wait); |
617 | |
618 | if (evdev->exist && !client->revoked) |
619 | mask = EPOLLOUT | EPOLLWRNORM; |
620 | else |
621 | mask = EPOLLHUP | EPOLLERR; |
622 | |
623 | if (client->packet_head != client->tail) |
624 | mask |= EPOLLIN | EPOLLRDNORM; |
625 | |
626 | return mask; |
627 | } |
628 | |
629 | #ifdef CONFIG_COMPAT |
630 | |
631 | #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8) |
632 | #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1) |
633 | |
634 | #ifdef __BIG_ENDIAN |
635 | static int bits_to_user(unsigned long *bits, unsigned int maxbit, |
636 | unsigned int maxlen, void __user *p, int compat) |
637 | { |
638 | int len, i; |
639 | |
640 | if (compat) { |
641 | len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t); |
642 | if (len > maxlen) |
643 | len = maxlen; |
644 | |
645 | for (i = 0; i < len / sizeof(compat_long_t); i++) |
646 | if (copy_to_user((compat_long_t __user *) p + i, |
647 | (compat_long_t *) bits + |
648 | i + 1 - ((i % 2) << 1), |
649 | sizeof(compat_long_t))) |
650 | return -EFAULT; |
651 | } else { |
652 | len = BITS_TO_LONGS(maxbit) * sizeof(long); |
653 | if (len > maxlen) |
654 | len = maxlen; |
655 | |
656 | if (copy_to_user(p, bits, len)) |
657 | return -EFAULT; |
658 | } |
659 | |
660 | return len; |
661 | } |
662 | |
663 | static int bits_from_user(unsigned long *bits, unsigned int maxbit, |
664 | unsigned int maxlen, const void __user *p, int compat) |
665 | { |
666 | int len, i; |
667 | |
668 | if (compat) { |
669 | if (maxlen % sizeof(compat_long_t)) |
670 | return -EINVAL; |
671 | |
672 | len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t); |
673 | if (len > maxlen) |
674 | len = maxlen; |
675 | |
676 | for (i = 0; i < len / sizeof(compat_long_t); i++) |
677 | if (copy_from_user((compat_long_t *) bits + |
678 | i + 1 - ((i % 2) << 1), |
679 | (compat_long_t __user *) p + i, |
680 | sizeof(compat_long_t))) |
681 | return -EFAULT; |
682 | if (i % 2) |
683 | *((compat_long_t *) bits + i - 1) = 0; |
684 | |
685 | } else { |
686 | if (maxlen % sizeof(long)) |
687 | return -EINVAL; |
688 | |
689 | len = BITS_TO_LONGS(maxbit) * sizeof(long); |
690 | if (len > maxlen) |
691 | len = maxlen; |
692 | |
693 | if (copy_from_user(bits, p, len)) |
694 | return -EFAULT; |
695 | } |
696 | |
697 | return len; |
698 | } |
699 | |
700 | #else |
701 | |
702 | static int bits_to_user(unsigned long *bits, unsigned int maxbit, |
703 | unsigned int maxlen, void __user *p, int compat) |
704 | { |
705 | int len = compat ? |
706 | BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) : |
707 | BITS_TO_LONGS(maxbit) * sizeof(long); |
708 | |
709 | if (len > maxlen) |
710 | len = maxlen; |
711 | |
712 | return copy_to_user(to: p, from: bits, n: len) ? -EFAULT : len; |
713 | } |
714 | |
715 | static int bits_from_user(unsigned long *bits, unsigned int maxbit, |
716 | unsigned int maxlen, const void __user *p, int compat) |
717 | { |
718 | size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long); |
719 | int len; |
720 | |
721 | if (maxlen % chunk_size) |
722 | return -EINVAL; |
723 | |
724 | len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit); |
725 | len *= chunk_size; |
726 | if (len > maxlen) |
727 | len = maxlen; |
728 | |
729 | return copy_from_user(to: bits, from: p, n: len) ? -EFAULT : len; |
730 | } |
731 | |
732 | #endif /* __BIG_ENDIAN */ |
733 | |
734 | #else |
735 | |
736 | static int bits_to_user(unsigned long *bits, unsigned int maxbit, |
737 | unsigned int maxlen, void __user *p, int compat) |
738 | { |
739 | int len = BITS_TO_LONGS(maxbit) * sizeof(long); |
740 | |
741 | if (len > maxlen) |
742 | len = maxlen; |
743 | |
744 | return copy_to_user(p, bits, len) ? -EFAULT : len; |
745 | } |
746 | |
747 | static int bits_from_user(unsigned long *bits, unsigned int maxbit, |
748 | unsigned int maxlen, const void __user *p, int compat) |
749 | { |
750 | int len; |
751 | |
752 | if (maxlen % sizeof(long)) |
753 | return -EINVAL; |
754 | |
755 | len = BITS_TO_LONGS(maxbit) * sizeof(long); |
756 | if (len > maxlen) |
757 | len = maxlen; |
758 | |
759 | return copy_from_user(bits, p, len) ? -EFAULT : len; |
760 | } |
761 | |
762 | #endif /* CONFIG_COMPAT */ |
763 | |
764 | static int str_to_user(const char *str, unsigned int maxlen, void __user *p) |
765 | { |
766 | int len; |
767 | |
768 | if (!str) |
769 | return -ENOENT; |
770 | |
771 | len = strlen(str) + 1; |
772 | if (len > maxlen) |
773 | len = maxlen; |
774 | |
775 | return copy_to_user(to: p, from: str, n: len) ? -EFAULT : len; |
776 | } |
777 | |
778 | static int handle_eviocgbit(struct input_dev *dev, |
779 | unsigned int type, unsigned int size, |
780 | void __user *p, int compat_mode) |
781 | { |
782 | unsigned long *bits; |
783 | int len; |
784 | |
785 | switch (type) { |
786 | |
787 | case 0: bits = dev->evbit; len = EV_MAX; break; |
788 | case EV_KEY: bits = dev->keybit; len = KEY_MAX; break; |
789 | case EV_REL: bits = dev->relbit; len = REL_MAX; break; |
790 | case EV_ABS: bits = dev->absbit; len = ABS_MAX; break; |
791 | case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break; |
792 | case EV_LED: bits = dev->ledbit; len = LED_MAX; break; |
793 | case EV_SND: bits = dev->sndbit; len = SND_MAX; break; |
794 | case EV_FF: bits = dev->ffbit; len = FF_MAX; break; |
795 | case EV_SW: bits = dev->swbit; len = SW_MAX; break; |
796 | default: return -EINVAL; |
797 | } |
798 | |
799 | return bits_to_user(bits, maxbit: len, maxlen: size, p, compat: compat_mode); |
800 | } |
801 | |
802 | static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p) |
803 | { |
804 | struct input_keymap_entry ke = { |
805 | .len = sizeof(unsigned int), |
806 | .flags = 0, |
807 | }; |
808 | int __user *ip = (int __user *)p; |
809 | int error; |
810 | |
811 | /* legacy case */ |
812 | if (copy_from_user(to: ke.scancode, from: p, n: sizeof(unsigned int))) |
813 | return -EFAULT; |
814 | |
815 | error = input_get_keycode(dev, ke: &ke); |
816 | if (error) |
817 | return error; |
818 | |
819 | if (put_user(ke.keycode, ip + 1)) |
820 | return -EFAULT; |
821 | |
822 | return 0; |
823 | } |
824 | |
825 | static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p) |
826 | { |
827 | struct input_keymap_entry ke; |
828 | int error; |
829 | |
830 | if (copy_from_user(to: &ke, from: p, n: sizeof(ke))) |
831 | return -EFAULT; |
832 | |
833 | error = input_get_keycode(dev, ke: &ke); |
834 | if (error) |
835 | return error; |
836 | |
837 | if (copy_to_user(to: p, from: &ke, n: sizeof(ke))) |
838 | return -EFAULT; |
839 | |
840 | return 0; |
841 | } |
842 | |
843 | static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p) |
844 | { |
845 | struct input_keymap_entry ke = { |
846 | .len = sizeof(unsigned int), |
847 | .flags = 0, |
848 | }; |
849 | int __user *ip = (int __user *)p; |
850 | |
851 | if (copy_from_user(to: ke.scancode, from: p, n: sizeof(unsigned int))) |
852 | return -EFAULT; |
853 | |
854 | if (get_user(ke.keycode, ip + 1)) |
855 | return -EFAULT; |
856 | |
857 | return input_set_keycode(dev, ke: &ke); |
858 | } |
859 | |
860 | static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p) |
861 | { |
862 | struct input_keymap_entry ke; |
863 | |
864 | if (copy_from_user(to: &ke, from: p, n: sizeof(ke))) |
865 | return -EFAULT; |
866 | |
867 | if (ke.len > sizeof(ke.scancode)) |
868 | return -EINVAL; |
869 | |
870 | return input_set_keycode(dev, ke: &ke); |
871 | } |
872 | |
873 | /* |
874 | * If we transfer state to the user, we should flush all pending events |
875 | * of the same type from the client's queue. Otherwise, they might end up |
876 | * with duplicate events, which can screw up client's state tracking. |
877 | * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED |
878 | * event so user-space will notice missing events. |
879 | * |
880 | * LOCKING: |
881 | * We need to take event_lock before buffer_lock to avoid dead-locks. But we |
882 | * need the even_lock only to guarantee consistent state. We can safely release |
883 | * it while flushing the queue. This allows input-core to handle filters while |
884 | * we flush the queue. |
885 | */ |
886 | static int evdev_handle_get_val(struct evdev_client *client, |
887 | struct input_dev *dev, unsigned int type, |
888 | unsigned long *bits, unsigned int maxbit, |
889 | unsigned int maxlen, void __user *p, |
890 | int compat) |
891 | { |
892 | int ret; |
893 | unsigned long *mem; |
894 | |
895 | mem = bitmap_alloc(nbits: maxbit, GFP_KERNEL); |
896 | if (!mem) |
897 | return -ENOMEM; |
898 | |
899 | spin_lock_irq(lock: &dev->event_lock); |
900 | spin_lock(lock: &client->buffer_lock); |
901 | |
902 | bitmap_copy(dst: mem, src: bits, nbits: maxbit); |
903 | |
904 | spin_unlock(lock: &dev->event_lock); |
905 | |
906 | __evdev_flush_queue(client, type); |
907 | |
908 | spin_unlock_irq(lock: &client->buffer_lock); |
909 | |
910 | ret = bits_to_user(bits: mem, maxbit, maxlen, p, compat); |
911 | if (ret < 0) |
912 | evdev_queue_syn_dropped(client); |
913 | |
914 | bitmap_free(bitmap: mem); |
915 | |
916 | return ret; |
917 | } |
918 | |
919 | static int evdev_handle_mt_request(struct input_dev *dev, |
920 | unsigned int size, |
921 | int __user *ip) |
922 | { |
923 | const struct input_mt *mt = dev->mt; |
924 | unsigned int code; |
925 | int max_slots; |
926 | int i; |
927 | |
928 | if (get_user(code, &ip[0])) |
929 | return -EFAULT; |
930 | if (!mt || !input_is_mt_value(axis: code)) |
931 | return -EINVAL; |
932 | |
933 | max_slots = (size - sizeof(__u32)) / sizeof(__s32); |
934 | for (i = 0; i < mt->num_slots && i < max_slots; i++) { |
935 | int value = input_mt_get_value(slot: &mt->slots[i], code); |
936 | if (put_user(value, &ip[1 + i])) |
937 | return -EFAULT; |
938 | } |
939 | |
940 | return 0; |
941 | } |
942 | |
943 | static int evdev_revoke(struct evdev *evdev, struct evdev_client *client, |
944 | struct file *file) |
945 | { |
946 | client->revoked = true; |
947 | evdev_ungrab(evdev, client); |
948 | input_flush_device(handle: &evdev->handle, file); |
949 | wake_up_interruptible_poll(&client->wait, EPOLLHUP | EPOLLERR); |
950 | |
951 | return 0; |
952 | } |
953 | |
954 | /* must be called with evdev-mutex held */ |
955 | static int evdev_set_mask(struct evdev_client *client, |
956 | unsigned int type, |
957 | const void __user *codes, |
958 | u32 codes_size, |
959 | int compat) |
960 | { |
961 | unsigned long flags, *mask, *oldmask; |
962 | size_t cnt; |
963 | int error; |
964 | |
965 | /* we allow unknown types and 'codes_size > size' for forward-compat */ |
966 | cnt = evdev_get_mask_cnt(type); |
967 | if (!cnt) |
968 | return 0; |
969 | |
970 | mask = bitmap_zalloc(nbits: cnt, GFP_KERNEL); |
971 | if (!mask) |
972 | return -ENOMEM; |
973 | |
974 | error = bits_from_user(bits: mask, maxbit: cnt - 1, maxlen: codes_size, p: codes, compat); |
975 | if (error < 0) { |
976 | bitmap_free(bitmap: mask); |
977 | return error; |
978 | } |
979 | |
980 | spin_lock_irqsave(&client->buffer_lock, flags); |
981 | oldmask = client->evmasks[type]; |
982 | client->evmasks[type] = mask; |
983 | spin_unlock_irqrestore(lock: &client->buffer_lock, flags); |
984 | |
985 | bitmap_free(bitmap: oldmask); |
986 | |
987 | return 0; |
988 | } |
989 | |
990 | /* must be called with evdev-mutex held */ |
991 | static int evdev_get_mask(struct evdev_client *client, |
992 | unsigned int type, |
993 | void __user *codes, |
994 | u32 codes_size, |
995 | int compat) |
996 | { |
997 | unsigned long *mask; |
998 | size_t cnt, size, xfer_size; |
999 | int i; |
1000 | int error; |
1001 | |
1002 | /* we allow unknown types and 'codes_size > size' for forward-compat */ |
1003 | cnt = evdev_get_mask_cnt(type); |
1004 | size = sizeof(unsigned long) * BITS_TO_LONGS(cnt); |
1005 | xfer_size = min_t(size_t, codes_size, size); |
1006 | |
1007 | if (cnt > 0) { |
1008 | mask = client->evmasks[type]; |
1009 | if (mask) { |
1010 | error = bits_to_user(bits: mask, maxbit: cnt - 1, |
1011 | maxlen: xfer_size, p: codes, compat); |
1012 | if (error < 0) |
1013 | return error; |
1014 | } else { |
1015 | /* fake mask with all bits set */ |
1016 | for (i = 0; i < xfer_size; i++) |
1017 | if (put_user(0xffU, (u8 __user *)codes + i)) |
1018 | return -EFAULT; |
1019 | } |
1020 | } |
1021 | |
1022 | if (xfer_size < codes_size) |
1023 | if (clear_user(to: codes + xfer_size, n: codes_size - xfer_size)) |
1024 | return -EFAULT; |
1025 | |
1026 | return 0; |
1027 | } |
1028 | |
1029 | static long evdev_do_ioctl(struct file *file, unsigned int cmd, |
1030 | void __user *p, int compat_mode) |
1031 | { |
1032 | struct evdev_client *client = file->private_data; |
1033 | struct evdev *evdev = client->evdev; |
1034 | struct input_dev *dev = evdev->handle.dev; |
1035 | struct input_absinfo abs; |
1036 | struct input_mask mask; |
1037 | struct ff_effect effect; |
1038 | int __user *ip = (int __user *)p; |
1039 | unsigned int i, t, u, v; |
1040 | unsigned int size; |
1041 | int error; |
1042 | |
1043 | /* First we check for fixed-length commands */ |
1044 | switch (cmd) { |
1045 | |
1046 | case EVIOCGVERSION: |
1047 | return put_user(EV_VERSION, ip); |
1048 | |
1049 | case EVIOCGID: |
1050 | if (copy_to_user(to: p, from: &dev->id, n: sizeof(struct input_id))) |
1051 | return -EFAULT; |
1052 | return 0; |
1053 | |
1054 | case EVIOCGREP: |
1055 | if (!test_bit(EV_REP, dev->evbit)) |
1056 | return -ENOSYS; |
1057 | if (put_user(dev->rep[REP_DELAY], ip)) |
1058 | return -EFAULT; |
1059 | if (put_user(dev->rep[REP_PERIOD], ip + 1)) |
1060 | return -EFAULT; |
1061 | return 0; |
1062 | |
1063 | case EVIOCSREP: |
1064 | if (!test_bit(EV_REP, dev->evbit)) |
1065 | return -ENOSYS; |
1066 | if (get_user(u, ip)) |
1067 | return -EFAULT; |
1068 | if (get_user(v, ip + 1)) |
1069 | return -EFAULT; |
1070 | |
1071 | input_inject_event(handle: &evdev->handle, EV_REP, REP_DELAY, value: u); |
1072 | input_inject_event(handle: &evdev->handle, EV_REP, REP_PERIOD, value: v); |
1073 | |
1074 | return 0; |
1075 | |
1076 | case EVIOCRMFF: |
1077 | return input_ff_erase(dev, effect_id: (int)(unsigned long) p, file); |
1078 | |
1079 | case EVIOCGEFFECTS: |
1080 | i = test_bit(EV_FF, dev->evbit) ? |
1081 | dev->ff->max_effects : 0; |
1082 | if (put_user(i, ip)) |
1083 | return -EFAULT; |
1084 | return 0; |
1085 | |
1086 | case EVIOCGRAB: |
1087 | if (p) |
1088 | return evdev_grab(evdev, client); |
1089 | else |
1090 | return evdev_ungrab(evdev, client); |
1091 | |
1092 | case EVIOCREVOKE: |
1093 | if (p) |
1094 | return -EINVAL; |
1095 | else |
1096 | return evdev_revoke(evdev, client, file); |
1097 | |
1098 | case EVIOCGMASK: { |
1099 | void __user *codes_ptr; |
1100 | |
1101 | if (copy_from_user(to: &mask, from: p, n: sizeof(mask))) |
1102 | return -EFAULT; |
1103 | |
1104 | codes_ptr = (void __user *)(unsigned long)mask.codes_ptr; |
1105 | return evdev_get_mask(client, |
1106 | type: mask.type, codes: codes_ptr, codes_size: mask.codes_size, |
1107 | compat: compat_mode); |
1108 | } |
1109 | |
1110 | case EVIOCSMASK: { |
1111 | const void __user *codes_ptr; |
1112 | |
1113 | if (copy_from_user(to: &mask, from: p, n: sizeof(mask))) |
1114 | return -EFAULT; |
1115 | |
1116 | codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr; |
1117 | return evdev_set_mask(client, |
1118 | type: mask.type, codes: codes_ptr, codes_size: mask.codes_size, |
1119 | compat: compat_mode); |
1120 | } |
1121 | |
1122 | case EVIOCSCLOCKID: |
1123 | if (copy_from_user(to: &i, from: p, n: sizeof(unsigned int))) |
1124 | return -EFAULT; |
1125 | |
1126 | return evdev_set_clk_type(client, clkid: i); |
1127 | |
1128 | case EVIOCGKEYCODE: |
1129 | return evdev_handle_get_keycode(dev, p); |
1130 | |
1131 | case EVIOCSKEYCODE: |
1132 | return evdev_handle_set_keycode(dev, p); |
1133 | |
1134 | case EVIOCGKEYCODE_V2: |
1135 | return evdev_handle_get_keycode_v2(dev, p); |
1136 | |
1137 | case EVIOCSKEYCODE_V2: |
1138 | return evdev_handle_set_keycode_v2(dev, p); |
1139 | } |
1140 | |
1141 | size = _IOC_SIZE(cmd); |
1142 | |
1143 | /* Now check variable-length commands */ |
1144 | #define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT)) |
1145 | switch (EVIOC_MASK_SIZE(cmd)) { |
1146 | |
1147 | case EVIOCGPROP(0): |
1148 | return bits_to_user(bits: dev->propbit, INPUT_PROP_MAX, |
1149 | maxlen: size, p, compat: compat_mode); |
1150 | |
1151 | case EVIOCGMTSLOTS(0): |
1152 | return evdev_handle_mt_request(dev, size, ip); |
1153 | |
1154 | case EVIOCGKEY(0): |
1155 | return evdev_handle_get_val(client, dev, EV_KEY, bits: dev->key, |
1156 | KEY_MAX, maxlen: size, p, compat: compat_mode); |
1157 | |
1158 | case EVIOCGLED(0): |
1159 | return evdev_handle_get_val(client, dev, EV_LED, bits: dev->led, |
1160 | LED_MAX, maxlen: size, p, compat: compat_mode); |
1161 | |
1162 | case EVIOCGSND(0): |
1163 | return evdev_handle_get_val(client, dev, EV_SND, bits: dev->snd, |
1164 | SND_MAX, maxlen: size, p, compat: compat_mode); |
1165 | |
1166 | case EVIOCGSW(0): |
1167 | return evdev_handle_get_val(client, dev, EV_SW, bits: dev->sw, |
1168 | SW_MAX, maxlen: size, p, compat: compat_mode); |
1169 | |
1170 | case EVIOCGNAME(0): |
1171 | return str_to_user(str: dev->name, maxlen: size, p); |
1172 | |
1173 | case EVIOCGPHYS(0): |
1174 | return str_to_user(str: dev->phys, maxlen: size, p); |
1175 | |
1176 | case EVIOCGUNIQ(0): |
1177 | return str_to_user(str: dev->uniq, maxlen: size, p); |
1178 | |
1179 | case EVIOC_MASK_SIZE(EVIOCSFF): |
1180 | if (input_ff_effect_from_user(buffer: p, size, effect: &effect)) |
1181 | return -EFAULT; |
1182 | |
1183 | error = input_ff_upload(dev, effect: &effect, file); |
1184 | if (error) |
1185 | return error; |
1186 | |
1187 | if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) |
1188 | return -EFAULT; |
1189 | |
1190 | return 0; |
1191 | } |
1192 | |
1193 | /* Multi-number variable-length handlers */ |
1194 | if (_IOC_TYPE(cmd) != 'E') |
1195 | return -EINVAL; |
1196 | |
1197 | if (_IOC_DIR(cmd) == _IOC_READ) { |
1198 | |
1199 | if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) |
1200 | return handle_eviocgbit(dev, |
1201 | _IOC_NR(cmd) & EV_MAX, size, |
1202 | p, compat_mode); |
1203 | |
1204 | if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) { |
1205 | |
1206 | if (!dev->absinfo) |
1207 | return -EINVAL; |
1208 | |
1209 | t = _IOC_NR(cmd) & ABS_MAX; |
1210 | abs = dev->absinfo[t]; |
1211 | |
1212 | if (copy_to_user(to: p, from: &abs, min_t(size_t, |
1213 | size, sizeof(struct input_absinfo)))) |
1214 | return -EFAULT; |
1215 | |
1216 | return 0; |
1217 | } |
1218 | } |
1219 | |
1220 | if (_IOC_DIR(cmd) == _IOC_WRITE) { |
1221 | |
1222 | if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) { |
1223 | |
1224 | if (!dev->absinfo) |
1225 | return -EINVAL; |
1226 | |
1227 | t = _IOC_NR(cmd) & ABS_MAX; |
1228 | |
1229 | if (copy_from_user(to: &abs, from: p, min_t(size_t, |
1230 | size, sizeof(struct input_absinfo)))) |
1231 | return -EFAULT; |
1232 | |
1233 | if (size < sizeof(struct input_absinfo)) |
1234 | abs.resolution = 0; |
1235 | |
1236 | /* We can't change number of reserved MT slots */ |
1237 | if (t == ABS_MT_SLOT) |
1238 | return -EINVAL; |
1239 | |
1240 | /* |
1241 | * Take event lock to ensure that we are not |
1242 | * changing device parameters in the middle |
1243 | * of event. |
1244 | */ |
1245 | spin_lock_irq(lock: &dev->event_lock); |
1246 | dev->absinfo[t] = abs; |
1247 | spin_unlock_irq(lock: &dev->event_lock); |
1248 | |
1249 | return 0; |
1250 | } |
1251 | } |
1252 | |
1253 | return -EINVAL; |
1254 | } |
1255 | |
1256 | static long evdev_ioctl_handler(struct file *file, unsigned int cmd, |
1257 | void __user *p, int compat_mode) |
1258 | { |
1259 | struct evdev_client *client = file->private_data; |
1260 | struct evdev *evdev = client->evdev; |
1261 | int retval; |
1262 | |
1263 | retval = mutex_lock_interruptible(&evdev->mutex); |
1264 | if (retval) |
1265 | return retval; |
1266 | |
1267 | if (!evdev->exist || client->revoked) { |
1268 | retval = -ENODEV; |
1269 | goto out; |
1270 | } |
1271 | |
1272 | retval = evdev_do_ioctl(file, cmd, p, compat_mode); |
1273 | |
1274 | out: |
1275 | mutex_unlock(lock: &evdev->mutex); |
1276 | return retval; |
1277 | } |
1278 | |
1279 | static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1280 | { |
1281 | return evdev_ioctl_handler(file, cmd, p: (void __user *)arg, compat_mode: 0); |
1282 | } |
1283 | |
1284 | #ifdef CONFIG_COMPAT |
1285 | static long evdev_ioctl_compat(struct file *file, |
1286 | unsigned int cmd, unsigned long arg) |
1287 | { |
1288 | return evdev_ioctl_handler(file, cmd, p: compat_ptr(uptr: arg), compat_mode: 1); |
1289 | } |
1290 | #endif |
1291 | |
1292 | static const struct file_operations evdev_fops = { |
1293 | .owner = THIS_MODULE, |
1294 | .read = evdev_read, |
1295 | .write = evdev_write, |
1296 | .poll = evdev_poll, |
1297 | .open = evdev_open, |
1298 | .release = evdev_release, |
1299 | .unlocked_ioctl = evdev_ioctl, |
1300 | #ifdef CONFIG_COMPAT |
1301 | .compat_ioctl = evdev_ioctl_compat, |
1302 | #endif |
1303 | .fasync = evdev_fasync, |
1304 | .llseek = no_llseek, |
1305 | }; |
1306 | |
1307 | /* |
1308 | * Mark device non-existent. This disables writes, ioctls and |
1309 | * prevents new users from opening the device. Already posted |
1310 | * blocking reads will stay, however new ones will fail. |
1311 | */ |
1312 | static void evdev_mark_dead(struct evdev *evdev) |
1313 | { |
1314 | mutex_lock(&evdev->mutex); |
1315 | evdev->exist = false; |
1316 | mutex_unlock(lock: &evdev->mutex); |
1317 | } |
1318 | |
1319 | static void evdev_cleanup(struct evdev *evdev) |
1320 | { |
1321 | struct input_handle *handle = &evdev->handle; |
1322 | |
1323 | evdev_mark_dead(evdev); |
1324 | evdev_hangup(evdev); |
1325 | |
1326 | /* evdev is marked dead so no one else accesses evdev->open */ |
1327 | if (evdev->open) { |
1328 | input_flush_device(handle, NULL); |
1329 | input_close_device(handle); |
1330 | } |
1331 | } |
1332 | |
1333 | /* |
1334 | * Create new evdev device. Note that input core serializes calls |
1335 | * to connect and disconnect. |
1336 | */ |
1337 | static int evdev_connect(struct input_handler *handler, struct input_dev *dev, |
1338 | const struct input_device_id *id) |
1339 | { |
1340 | struct evdev *evdev; |
1341 | int minor; |
1342 | int dev_no; |
1343 | int error; |
1344 | |
1345 | minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, allow_dynamic: true); |
1346 | if (minor < 0) { |
1347 | error = minor; |
1348 | pr_err("failed to reserve new minor: %d\n" , error); |
1349 | return error; |
1350 | } |
1351 | |
1352 | evdev = kzalloc(size: sizeof(struct evdev), GFP_KERNEL); |
1353 | if (!evdev) { |
1354 | error = -ENOMEM; |
1355 | goto err_free_minor; |
1356 | } |
1357 | |
1358 | INIT_LIST_HEAD(list: &evdev->client_list); |
1359 | spin_lock_init(&evdev->client_lock); |
1360 | mutex_init(&evdev->mutex); |
1361 | evdev->exist = true; |
1362 | |
1363 | dev_no = minor; |
1364 | /* Normalize device number if it falls into legacy range */ |
1365 | if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS) |
1366 | dev_no -= EVDEV_MINOR_BASE; |
1367 | dev_set_name(dev: &evdev->dev, name: "event%d" , dev_no); |
1368 | |
1369 | evdev->handle.dev = input_get_device(dev); |
1370 | evdev->handle.name = dev_name(dev: &evdev->dev); |
1371 | evdev->handle.handler = handler; |
1372 | evdev->handle.private = evdev; |
1373 | |
1374 | evdev->dev.devt = MKDEV(INPUT_MAJOR, minor); |
1375 | evdev->dev.class = &input_class; |
1376 | evdev->dev.parent = &dev->dev; |
1377 | evdev->dev.release = evdev_free; |
1378 | device_initialize(dev: &evdev->dev); |
1379 | |
1380 | error = input_register_handle(&evdev->handle); |
1381 | if (error) |
1382 | goto err_free_evdev; |
1383 | |
1384 | cdev_init(&evdev->cdev, &evdev_fops); |
1385 | |
1386 | error = cdev_device_add(cdev: &evdev->cdev, dev: &evdev->dev); |
1387 | if (error) |
1388 | goto err_cleanup_evdev; |
1389 | |
1390 | return 0; |
1391 | |
1392 | err_cleanup_evdev: |
1393 | evdev_cleanup(evdev); |
1394 | input_unregister_handle(&evdev->handle); |
1395 | err_free_evdev: |
1396 | put_device(dev: &evdev->dev); |
1397 | err_free_minor: |
1398 | input_free_minor(minor); |
1399 | return error; |
1400 | } |
1401 | |
1402 | static void evdev_disconnect(struct input_handle *handle) |
1403 | { |
1404 | struct evdev *evdev = handle->private; |
1405 | |
1406 | cdev_device_del(cdev: &evdev->cdev, dev: &evdev->dev); |
1407 | evdev_cleanup(evdev); |
1408 | input_free_minor(MINOR(evdev->dev.devt)); |
1409 | input_unregister_handle(handle); |
1410 | put_device(dev: &evdev->dev); |
1411 | } |
1412 | |
1413 | static const struct input_device_id evdev_ids[] = { |
1414 | { .driver_info = 1 }, /* Matches all devices */ |
1415 | { }, /* Terminating zero entry */ |
1416 | }; |
1417 | |
1418 | MODULE_DEVICE_TABLE(input, evdev_ids); |
1419 | |
1420 | static struct input_handler evdev_handler = { |
1421 | .event = evdev_event, |
1422 | .events = evdev_events, |
1423 | .connect = evdev_connect, |
1424 | .disconnect = evdev_disconnect, |
1425 | .legacy_minors = true, |
1426 | .minor = EVDEV_MINOR_BASE, |
1427 | .name = "evdev" , |
1428 | .id_table = evdev_ids, |
1429 | }; |
1430 | |
1431 | static int __init evdev_init(void) |
1432 | { |
1433 | return input_register_handler(&evdev_handler); |
1434 | } |
1435 | |
1436 | static void __exit evdev_exit(void) |
1437 | { |
1438 | input_unregister_handler(&evdev_handler); |
1439 | } |
1440 | |
1441 | module_init(evdev_init); |
1442 | module_exit(evdev_exit); |
1443 | |
1444 | MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>" ); |
1445 | MODULE_DESCRIPTION("Input driver event char devices" ); |
1446 | MODULE_LICENSE("GPL" ); |
1447 | |