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split dev_queue
[cor.git] / drivers / hid / hidraw.c
blobc3fc0ceb80963c331f1515bacdfa51883708d1ae
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * HID raw devices, giving access to raw HID events.
4 *
5 * In comparison to hiddev, this device does not process the
6 * hid events at all (no parsing, no lookups). This lets applications
7 * to work on raw hid events as they want to, and avoids a need to
8 * use a transport-specific userspace libhid/libusb libraries.
9 *
10 * Copyright (c) 2007-2014 Jiri Kosina
11 */
12
13
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/fs.h>
17 #include <linux/module.h>
18 #include <linux/errno.h>
19 #include <linux/kernel.h>
20 #include <linux/init.h>
21 #include <linux/cdev.h>
22 #include <linux/poll.h>
23 #include <linux/device.h>
24 #include <linux/major.h>
25 #include <linux/slab.h>
26 #include <linux/hid.h>
27 #include <linux/mutex.h>
28 #include <linux/sched/signal.h>
29 #include <linux/string.h>
30
31 #include <linux/hidraw.h>
32
33 static int hidraw_major;
34 static struct cdev hidraw_cdev;
35 static struct class *hidraw_class;
36 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
37 static DEFINE_MUTEX(minors_lock);
38
39 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
40 {
41 struct hidraw_list *list = file->private_data;
42 int ret = 0, len;
43 DECLARE_WAITQUEUE(wait, current);
44
45 mutex_lock(&list->read_mutex);
46
47 while (ret == 0) {
48 if (list->head == list->tail) {
49 add_wait_queue(&list->hidraw->wait, &wait);
50 set_current_state(TASK_INTERRUPTIBLE);
51
52 while (list->head == list->tail) {
53 if (signal_pending(current)) {
54 ret = -ERESTARTSYS;
55 break;
56 }
57 if (!list->hidraw->exist) {
58 ret = -EIO;
59 break;
60 }
61 if (file->f_flags & O_NONBLOCK) {
62 ret = -EAGAIN;
63 break;
64 }
65
66 /* allow O_NONBLOCK to work well from other threads */
67 mutex_unlock(&list->read_mutex);
68 schedule();
69 mutex_lock(&list->read_mutex);
70 set_current_state(TASK_INTERRUPTIBLE);
71 }
72
73 set_current_state(TASK_RUNNING);
74 remove_wait_queue(&list->hidraw->wait, &wait);
75 }
76
77 if (ret)
78 goto out;
79
80 len = list->buffer[list->tail].len > count ?
81 count : list->buffer[list->tail].len;
82
83 if (list->buffer[list->tail].value) {
84 if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
85 ret = -EFAULT;
86 goto out;
87 }
88 ret = len;
89 }
90
91 kfree(list->buffer[list->tail].value);
92 list->buffer[list->tail].value = NULL;
93 list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
94 }
95 out:
96 mutex_unlock(&list->read_mutex);
97 return ret;
98 }
99
100 /*
101 * The first byte of the report buffer is expected to be a report number.
102 */
103 static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
104 {
105 unsigned int minor = iminor(file_inode(file));
106 struct hid_device *dev;
107 __u8 *buf;
108 int ret = 0;
109
110 lockdep_assert_held(&minors_lock);
111
112 if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
113 ret = -ENODEV;
114 goto out;
115 }
116
117 dev = hidraw_table[minor]->hid;
118
119 if (count > HID_MAX_BUFFER_SIZE) {
120 hid_warn(dev, "pid %d passed too large report\n",
121 task_pid_nr(current));
122 ret = -EINVAL;
123 goto out;
124 }
125
126 if (count < 2) {
127 hid_warn(dev, "pid %d passed too short report\n",
128 task_pid_nr(current));
129 ret = -EINVAL;
130 goto out;
131 }
132
133 buf = memdup_user(buffer, count);
134 if (IS_ERR(buf)) {
135 ret = PTR_ERR(buf);
136 goto out;
137 }
138
139 if ((report_type == HID_OUTPUT_REPORT) &&
140 !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
141 ret = hid_hw_output_report(dev, buf, count);
142 /*
143 * compatibility with old implementation of USB-HID and I2C-HID:
144 * if the device does not support receiving output reports,
145 * on an interrupt endpoint, fallback to SET_REPORT HID command.
146 */
147 if (ret != -ENOSYS)
148 goto out_free;
149 }
150
151 ret = hid_hw_raw_request(dev, buf[0], buf, count, report_type,
152 HID_REQ_SET_REPORT);
153
154 out_free:
155 kfree(buf);
156 out:
157 return ret;
158 }
159
160 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
161 {
162 ssize_t ret;
163 mutex_lock(&minors_lock);
164 ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
165 mutex_unlock(&minors_lock);
166 return ret;
167 }
168
169
170 /*
171 * This function performs a Get_Report transfer over the control endpoint
172 * per section 7.2.1 of the HID specification, version 1.1. The first byte
173 * of buffer is the report number to request, or 0x0 if the defice does not
174 * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
175 * or HID_INPUT_REPORT.
176 */
177 static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
178 {
179 unsigned int minor = iminor(file_inode(file));
180 struct hid_device *dev;
181 __u8 *buf;
182 int ret = 0, len;
183 unsigned char report_number;
184
185 lockdep_assert_held(&minors_lock);
186
187 if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
188 ret = -ENODEV;
189 goto out;
190 }
191
192 dev = hidraw_table[minor]->hid;
193
194 if (!dev->ll_driver->raw_request) {
195 ret = -ENODEV;
196 goto out;
197 }
198
199 if (count > HID_MAX_BUFFER_SIZE) {
200 hid_warn(dev, "pid %d passed too large report\n",
201 task_pid_nr(current));
202 ret = -EINVAL;
203 goto out;
204 }
205
206 if (count < 2) {
207 hid_warn(dev, "pid %d passed too short report\n",
208 task_pid_nr(current));
209 ret = -EINVAL;
210 goto out;
211 }
212
213 buf = kmalloc(count, GFP_KERNEL);
214 if (!buf) {
215 ret = -ENOMEM;
216 goto out;
217 }
218
219 /*
220 * Read the first byte from the user. This is the report number,
221 * which is passed to hid_hw_raw_request().
222 */
223 if (copy_from_user(&report_number, buffer, 1)) {
224 ret = -EFAULT;
225 goto out_free;
226 }
227
228 ret = hid_hw_raw_request(dev, report_number, buf, count, report_type,
229 HID_REQ_GET_REPORT);
230
231 if (ret < 0)
232 goto out_free;
233
234 len = (ret < count) ? ret : count;
235
236 if (copy_to_user(buffer, buf, len)) {
237 ret = -EFAULT;
238 goto out_free;
239 }
240
241 ret = len;
242
243 out_free:
244 kfree(buf);
245 out:
246 return ret;
247 }
248
249 static __poll_t hidraw_poll(struct file *file, poll_table *wait)
250 {
251 struct hidraw_list *list = file->private_data;
252
253 poll_wait(file, &list->hidraw->wait, wait);
254 if (list->head != list->tail)
255 return EPOLLIN | EPOLLRDNORM | EPOLLOUT;
256 if (!list->hidraw->exist)
257 return EPOLLERR | EPOLLHUP;
258 return 0;
259 }
260
261 static int hidraw_open(struct inode *inode, struct file *file)
262 {
263 unsigned int minor = iminor(inode);
264 struct hidraw *dev;
265 struct hidraw_list *list;
266 unsigned long flags;
267 int err = 0;
268
269 if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
270 err = -ENOMEM;
271 goto out;
272 }
273
274 mutex_lock(&minors_lock);
275 if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
276 err = -ENODEV;
277 goto out_unlock;
278 }
279
280 dev = hidraw_table[minor];
281 if (!dev->open++) {
282 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
283 if (err < 0) {
284 dev->open--;
285 goto out_unlock;
286 }
287
288 err = hid_hw_open(dev->hid);
289 if (err < 0) {
290 hid_hw_power(dev->hid, PM_HINT_NORMAL);
291 dev->open--;
292 goto out_unlock;
293 }
294 }
295
296 list->hidraw = hidraw_table[minor];
297 mutex_init(&list->read_mutex);
298 spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
299 list_add_tail(&list->node, &hidraw_table[minor]->list);
300 spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
301 file->private_data = list;
302 out_unlock:
303 mutex_unlock(&minors_lock);
304 out:
305 if (err < 0)
306 kfree(list);
307 return err;
308
309 }
310
311 static int hidraw_fasync(int fd, struct file *file, int on)
312 {
313 struct hidraw_list *list = file->private_data;
314
315 return fasync_helper(fd, file, on, &list->fasync);
316 }
317
318 static void drop_ref(struct hidraw *hidraw, int exists_bit)
319 {
320 if (exists_bit) {
321 hidraw->exist = 0;
322 if (hidraw->open) {
323 hid_hw_close(hidraw->hid);
324 wake_up_interruptible(&hidraw->wait);
325 }
326 device_destroy(hidraw_class,
327 MKDEV(hidraw_major, hidraw->minor));
328 } else {
329 --hidraw->open;
330 }
331 if (!hidraw->open) {
332 if (!hidraw->exist) {
333 hidraw_table[hidraw->minor] = NULL;
334 kfree(hidraw);
335 } else {
336 /* close device for last reader */
337 hid_hw_close(hidraw->hid);
338 hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
339 }
340 }
341 }
342
343 static int hidraw_release(struct inode * inode, struct file * file)
344 {
345 unsigned int minor = iminor(inode);
346 struct hidraw_list *list = file->private_data;
347 unsigned long flags;
348
349 mutex_lock(&minors_lock);
350
351 spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
352 list_del(&list->node);
353 spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
354 kfree(list);
355
356 drop_ref(hidraw_table[minor], 0);
357
358 mutex_unlock(&minors_lock);
359 return 0;
360 }
361
362 static long hidraw_ioctl(struct file *file, unsigned int cmd,
363 unsigned long arg)
364 {
365 struct inode *inode = file_inode(file);
366 unsigned int minor = iminor(inode);
367 long ret = 0;
368 struct hidraw *dev;
369 void __user *user_arg = (void __user*) arg;
370
371 mutex_lock(&minors_lock);
372 dev = hidraw_table[minor];
373 if (!dev || !dev->exist) {
374 ret = -ENODEV;
375 goto out;
376 }
377
378 switch (cmd) {
379 case HIDIOCGRDESCSIZE:
380 if (put_user(dev->hid->rsize, (int __user *)arg))
381 ret = -EFAULT;
382 break;
383
384 case HIDIOCGRDESC:
385 {
386 __u32 len;
387
388 if (get_user(len, (int __user *)arg))
389 ret = -EFAULT;
390 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
391 ret = -EINVAL;
392 else if (copy_to_user(user_arg + offsetof(
393 struct hidraw_report_descriptor,
394 value[0]),
395 dev->hid->rdesc,
396 min(dev->hid->rsize, len)))
397 ret = -EFAULT;
398 break;
399 }
400 case HIDIOCGRAWINFO:
401 {
402 struct hidraw_devinfo dinfo;
403
404 dinfo.bustype = dev->hid->bus;
405 dinfo.vendor = dev->hid->vendor;
406 dinfo.product = dev->hid->product;
407 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
408 ret = -EFAULT;
409 break;
410 }
411 default:
412 {
413 struct hid_device *hid = dev->hid;
414 if (_IOC_TYPE(cmd) != 'H') {
415 ret = -EINVAL;
416 break;
417 }
418
419 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
420 int len = _IOC_SIZE(cmd);
421 ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
422 break;
423 }
424 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
425 int len = _IOC_SIZE(cmd);
426 ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
427 break;
428 }
429
430 /* Begin Read-only ioctls. */
431 if (_IOC_DIR(cmd) != _IOC_READ) {
432 ret = -EINVAL;
433 break;
434 }
435
436 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
437 int len = strlen(hid->name) + 1;
438 if (len > _IOC_SIZE(cmd))
439 len = _IOC_SIZE(cmd);
440 ret = copy_to_user(user_arg, hid->name, len) ?
441 -EFAULT : len;
442 break;
443 }
444
445 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
446 int len = strlen(hid->phys) + 1;
447 if (len > _IOC_SIZE(cmd))
448 len = _IOC_SIZE(cmd);
449 ret = copy_to_user(user_arg, hid->phys, len) ?
450 -EFAULT : len;
451 break;
452 }
453 }
454
455 ret = -ENOTTY;
456 }
457 out:
458 mutex_unlock(&minors_lock);
459 return ret;
460 }
461
462 static const struct file_operations hidraw_ops = {
463 .owner = THIS_MODULE,
464 .read = hidraw_read,
465 .write = hidraw_write,
466 .poll = hidraw_poll,
467 .open = hidraw_open,
468 .release = hidraw_release,
469 .unlocked_ioctl = hidraw_ioctl,
470 .fasync = hidraw_fasync,
471 .compat_ioctl = compat_ptr_ioctl,
472 .llseek = noop_llseek,
473 };
474
475 int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
476 {
477 struct hidraw *dev = hid->hidraw;
478 struct hidraw_list *list;
479 int ret = 0;
480 unsigned long flags;
481
482 spin_lock_irqsave(&dev->list_lock, flags);
483 list_for_each_entry(list, &dev->list, node) {
484 int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
485
486 if (new_head == list->tail)
487 continue;
488
489 if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
490 ret = -ENOMEM;
491 break;
492 }
493 list->buffer[list->head].len = len;
494 list->head = new_head;
495 kill_fasync(&list->fasync, SIGIO, POLL_IN);
496 }
497 spin_unlock_irqrestore(&dev->list_lock, flags);
498
499 wake_up_interruptible(&dev->wait);
500 return ret;
501 }
502 EXPORT_SYMBOL_GPL(hidraw_report_event);
503
504 int hidraw_connect(struct hid_device *hid)
505 {
506 int minor, result;
507 struct hidraw *dev;
508
509 /* we accept any HID device, all applications */
510
511 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
512 if (!dev)
513 return -ENOMEM;
514
515 result = -EINVAL;
516
517 mutex_lock(&minors_lock);
518
519 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
520 if (hidraw_table[minor])
521 continue;
522 hidraw_table[minor] = dev;
523 result = 0;
524 break;
525 }
526
527 if (result) {
528 mutex_unlock(&minors_lock);
529 kfree(dev);
530 goto out;
531 }
532
533 dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
534 NULL, "%s%d", "hidraw", minor);
535
536 if (IS_ERR(dev->dev)) {
537 hidraw_table[minor] = NULL;
538 mutex_unlock(&minors_lock);
539 result = PTR_ERR(dev->dev);
540 kfree(dev);
541 goto out;
542 }
543
544 init_waitqueue_head(&dev->wait);
545 spin_lock_init(&dev->list_lock);
546 INIT_LIST_HEAD(&dev->list);
547
548 dev->hid = hid;
549 dev->minor = minor;
550
551 dev->exist = 1;
552 hid->hidraw = dev;
553
554 mutex_unlock(&minors_lock);
555 out:
556 return result;
557
558 }
559 EXPORT_SYMBOL_GPL(hidraw_connect);
560
561 void hidraw_disconnect(struct hid_device *hid)
562 {
563 struct hidraw *hidraw = hid->hidraw;
564
565 mutex_lock(&minors_lock);
566
567 drop_ref(hidraw, 1);
568
569 mutex_unlock(&minors_lock);
570 }
571 EXPORT_SYMBOL_GPL(hidraw_disconnect);
572
573 int __init hidraw_init(void)
574 {
575 int result;
576 dev_t dev_id;
577
578 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
579 HIDRAW_MAX_DEVICES, "hidraw");
580 if (result < 0) {
581 pr_warn("can't get major number\n");
582 goto out;
583 }
584
585 hidraw_major = MAJOR(dev_id);
586
587 hidraw_class = class_create(THIS_MODULE, "hidraw");
588 if (IS_ERR(hidraw_class)) {
589 result = PTR_ERR(hidraw_class);
590 goto error_cdev;
591 }
592
593 cdev_init(&hidraw_cdev, &hidraw_ops);
594 result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
595 if (result < 0)
596 goto error_class;
597
598 pr_info("raw HID events driver (C) Jiri Kosina\n");
599 out:
600 return result;
601
602 error_class:
603 class_destroy(hidraw_class);
604 error_cdev:
605 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
606 goto out;
607 }
608
609 void hidraw_exit(void)
610 {
611 dev_t dev_id = MKDEV(hidraw_major, 0);
612
613 cdev_del(&hidraw_cdev);
614 class_destroy(hidraw_class);
615 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
616
617 }
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