fbmem: don't allow too huge resolutions
[linux-2.6-microblaze.git] / drivers / hid / hidraw.c
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 device 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         __poll_t mask = EPOLLOUT | EPOLLWRNORM; /* hidraw is always writable */
253
254         poll_wait(file, &list->hidraw->wait, wait);
255         if (list->head != list->tail)
256                 mask |= EPOLLIN | EPOLLRDNORM;
257         if (!list->hidraw->exist)
258                 mask |= EPOLLERR | EPOLLHUP;
259         return mask;
260 }
261
262 static int hidraw_open(struct inode *inode, struct file *file)
263 {
264         unsigned int minor = iminor(inode);
265         struct hidraw *dev;
266         struct hidraw_list *list;
267         unsigned long flags;
268         int err = 0;
269
270         if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
271                 err = -ENOMEM;
272                 goto out;
273         }
274
275         mutex_lock(&minors_lock);
276         if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
277                 err = -ENODEV;
278                 goto out_unlock;
279         }
280
281         dev = hidraw_table[minor];
282         if (!dev->open++) {
283                 err = hid_hw_power(dev->hid, PM_HINT_FULLON);
284                 if (err < 0) {
285                         dev->open--;
286                         goto out_unlock;
287                 }
288
289                 err = hid_hw_open(dev->hid);
290                 if (err < 0) {
291                         hid_hw_power(dev->hid, PM_HINT_NORMAL);
292                         dev->open--;
293                         goto out_unlock;
294                 }
295         }
296
297         list->hidraw = hidraw_table[minor];
298         mutex_init(&list->read_mutex);
299         spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
300         list_add_tail(&list->node, &hidraw_table[minor]->list);
301         spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
302         file->private_data = list;
303 out_unlock:
304         mutex_unlock(&minors_lock);
305 out:
306         if (err < 0)
307                 kfree(list);
308         return err;
309
310 }
311
312 static int hidraw_fasync(int fd, struct file *file, int on)
313 {
314         struct hidraw_list *list = file->private_data;
315
316         return fasync_helper(fd, file, on, &list->fasync);
317 }
318
319 static void drop_ref(struct hidraw *hidraw, int exists_bit)
320 {
321         if (exists_bit) {
322                 hidraw->exist = 0;
323                 if (hidraw->open) {
324                         hid_hw_close(hidraw->hid);
325                         wake_up_interruptible(&hidraw->wait);
326                 }
327                 device_destroy(hidraw_class,
328                                MKDEV(hidraw_major, hidraw->minor));
329         } else {
330                 --hidraw->open;
331         }
332         if (!hidraw->open) {
333                 if (!hidraw->exist) {
334                         hidraw_table[hidraw->minor] = NULL;
335                         kfree(hidraw);
336                 } else {
337                         /* close device for last reader */
338                         hid_hw_close(hidraw->hid);
339                         hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
340                 }
341         }
342 }
343
344 static int hidraw_release(struct inode * inode, struct file * file)
345 {
346         unsigned int minor = iminor(inode);
347         struct hidraw_list *list = file->private_data;
348         unsigned long flags;
349
350         mutex_lock(&minors_lock);
351
352         spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
353         list_del(&list->node);
354         spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
355         kfree(list);
356
357         drop_ref(hidraw_table[minor], 0);
358
359         mutex_unlock(&minors_lock);
360         return 0;
361 }
362
363 static long hidraw_ioctl(struct file *file, unsigned int cmd,
364                                                         unsigned long arg)
365 {
366         struct inode *inode = file_inode(file);
367         unsigned int minor = iminor(inode);
368         long ret = 0;
369         struct hidraw *dev;
370         void __user *user_arg = (void __user*) arg;
371
372         mutex_lock(&minors_lock);
373         dev = hidraw_table[minor];
374         if (!dev || !dev->exist) {
375                 ret = -ENODEV;
376                 goto out;
377         }
378
379         switch (cmd) {
380                 case HIDIOCGRDESCSIZE:
381                         if (put_user(dev->hid->rsize, (int __user *)arg))
382                                 ret = -EFAULT;
383                         break;
384
385                 case HIDIOCGRDESC:
386                         {
387                                 __u32 len;
388
389                                 if (get_user(len, (int __user *)arg))
390                                         ret = -EFAULT;
391                                 else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
392                                         ret = -EINVAL;
393                                 else if (copy_to_user(user_arg + offsetof(
394                                         struct hidraw_report_descriptor,
395                                         value[0]),
396                                         dev->hid->rdesc,
397                                         min(dev->hid->rsize, len)))
398                                         ret = -EFAULT;
399                                 break;
400                         }
401                 case HIDIOCGRAWINFO:
402                         {
403                                 struct hidraw_devinfo dinfo;
404
405                                 dinfo.bustype = dev->hid->bus;
406                                 dinfo.vendor = dev->hid->vendor;
407                                 dinfo.product = dev->hid->product;
408                                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
409                                         ret = -EFAULT;
410                                 break;
411                         }
412                 default:
413                         {
414                                 struct hid_device *hid = dev->hid;
415                                 if (_IOC_TYPE(cmd) != 'H') {
416                                         ret = -EINVAL;
417                                         break;
418                                 }
419
420                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
421                                         int len = _IOC_SIZE(cmd);
422                                         ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
423                                         break;
424                                 }
425                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
426                                         int len = _IOC_SIZE(cmd);
427                                         ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
428                                         break;
429                                 }
430
431                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSINPUT(0))) {
432                                         int len = _IOC_SIZE(cmd);
433                                         ret = hidraw_send_report(file, user_arg, len, HID_INPUT_REPORT);
434                                         break;
435                                 }
436                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGINPUT(0))) {
437                                         int len = _IOC_SIZE(cmd);
438                                         ret = hidraw_get_report(file, user_arg, len, HID_INPUT_REPORT);
439                                         break;
440                                 }
441
442                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSOUTPUT(0))) {
443                                         int len = _IOC_SIZE(cmd);
444                                         ret = hidraw_send_report(file, user_arg, len, HID_OUTPUT_REPORT);
445                                         break;
446                                 }
447                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGOUTPUT(0))) {
448                                         int len = _IOC_SIZE(cmd);
449                                         ret = hidraw_get_report(file, user_arg, len, HID_OUTPUT_REPORT);
450                                         break;
451                                 }
452
453                                 /* Begin Read-only ioctls. */
454                                 if (_IOC_DIR(cmd) != _IOC_READ) {
455                                         ret = -EINVAL;
456                                         break;
457                                 }
458
459                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
460                                         int len = strlen(hid->name) + 1;
461                                         if (len > _IOC_SIZE(cmd))
462                                                 len = _IOC_SIZE(cmd);
463                                         ret = copy_to_user(user_arg, hid->name, len) ?
464                                                 -EFAULT : len;
465                                         break;
466                                 }
467
468                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
469                                         int len = strlen(hid->phys) + 1;
470                                         if (len > _IOC_SIZE(cmd))
471                                                 len = _IOC_SIZE(cmd);
472                                         ret = copy_to_user(user_arg, hid->phys, len) ?
473                                                 -EFAULT : len;
474                                         break;
475                                 }
476
477                                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWUNIQ(0))) {
478                                         int len = strlen(hid->uniq) + 1;
479                                         if (len > _IOC_SIZE(cmd))
480                                                 len = _IOC_SIZE(cmd);
481                                         ret = copy_to_user(user_arg, hid->uniq, len) ?
482                                                 -EFAULT : len;
483                                         break;
484                                 }
485                         }
486
487                 ret = -ENOTTY;
488         }
489 out:
490         mutex_unlock(&minors_lock);
491         return ret;
492 }
493
494 static const struct file_operations hidraw_ops = {
495         .owner =        THIS_MODULE,
496         .read =         hidraw_read,
497         .write =        hidraw_write,
498         .poll =         hidraw_poll,
499         .open =         hidraw_open,
500         .release =      hidraw_release,
501         .unlocked_ioctl = hidraw_ioctl,
502         .fasync =       hidraw_fasync,
503         .compat_ioctl   = compat_ptr_ioctl,
504         .llseek =       noop_llseek,
505 };
506
507 int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
508 {
509         struct hidraw *dev = hid->hidraw;
510         struct hidraw_list *list;
511         int ret = 0;
512         unsigned long flags;
513
514         spin_lock_irqsave(&dev->list_lock, flags);
515         list_for_each_entry(list, &dev->list, node) {
516                 int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
517
518                 if (new_head == list->tail)
519                         continue;
520
521                 if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
522                         ret = -ENOMEM;
523                         break;
524                 }
525                 list->buffer[list->head].len = len;
526                 list->head = new_head;
527                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
528         }
529         spin_unlock_irqrestore(&dev->list_lock, flags);
530
531         wake_up_interruptible(&dev->wait);
532         return ret;
533 }
534 EXPORT_SYMBOL_GPL(hidraw_report_event);
535
536 int hidraw_connect(struct hid_device *hid)
537 {
538         int minor, result;
539         struct hidraw *dev;
540
541         /* we accept any HID device, all applications */
542
543         dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
544         if (!dev)
545                 return -ENOMEM;
546
547         result = -EINVAL;
548
549         mutex_lock(&minors_lock);
550
551         for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
552                 if (hidraw_table[minor])
553                         continue;
554                 hidraw_table[minor] = dev;
555                 result = 0;
556                 break;
557         }
558
559         if (result) {
560                 mutex_unlock(&minors_lock);
561                 kfree(dev);
562                 goto out;
563         }
564
565         dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
566                                  NULL, "%s%d", "hidraw", minor);
567
568         if (IS_ERR(dev->dev)) {
569                 hidraw_table[minor] = NULL;
570                 mutex_unlock(&minors_lock);
571                 result = PTR_ERR(dev->dev);
572                 kfree(dev);
573                 goto out;
574         }
575
576         init_waitqueue_head(&dev->wait);
577         spin_lock_init(&dev->list_lock);
578         INIT_LIST_HEAD(&dev->list);
579
580         dev->hid = hid;
581         dev->minor = minor;
582
583         dev->exist = 1;
584         hid->hidraw = dev;
585
586         mutex_unlock(&minors_lock);
587 out:
588         return result;
589
590 }
591 EXPORT_SYMBOL_GPL(hidraw_connect);
592
593 void hidraw_disconnect(struct hid_device *hid)
594 {
595         struct hidraw *hidraw = hid->hidraw;
596
597         mutex_lock(&minors_lock);
598
599         drop_ref(hidraw, 1);
600
601         mutex_unlock(&minors_lock);
602 }
603 EXPORT_SYMBOL_GPL(hidraw_disconnect);
604
605 int __init hidraw_init(void)
606 {
607         int result;
608         dev_t dev_id;
609
610         result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
611                         HIDRAW_MAX_DEVICES, "hidraw");
612         if (result < 0) {
613                 pr_warn("can't get major number\n");
614                 goto out;
615         }
616
617         hidraw_major = MAJOR(dev_id);
618
619         hidraw_class = class_create(THIS_MODULE, "hidraw");
620         if (IS_ERR(hidraw_class)) {
621                 result = PTR_ERR(hidraw_class);
622                 goto error_cdev;
623         }
624
625         cdev_init(&hidraw_cdev, &hidraw_ops);
626         result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
627         if (result < 0)
628                 goto error_class;
629
630         pr_info("raw HID events driver (C) Jiri Kosina\n");
631 out:
632         return result;
633
634 error_class:
635         class_destroy(hidraw_class);
636 error_cdev:
637         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
638         goto out;
639 }
640
641 void hidraw_exit(void)
642 {
643         dev_t dev_id = MKDEV(hidraw_major, 0);
644
645         cdev_del(&hidraw_cdev);
646         class_destroy(hidraw_class);
647         unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
648
649 }