1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * User-space I/O driver support for HID subsystem 4 * Copyright (c) 2012 David Herrmann 5 */ 6 7/* 8 */ 9 10#include <linux/atomic.h> 11#include <linux/compat.h> 12#include <linux/cred.h> 13#include <linux/device.h> 14#include <linux/fs.h> 15#include <linux/hid.h> 16#include <linux/input.h> 17#include <linux/miscdevice.h> 18#include <linux/module.h> 19#include <linux/mutex.h> 20#include <linux/poll.h> 21#include <linux/sched.h> 22#include <linux/spinlock.h> 23#include <linux/uhid.h> 24#include <linux/wait.h> 25 26#define UHID_NAME "uhid" 27#define UHID_BUFSIZE 32 28 29struct uhid_device { 30 struct mutex devlock; 31 32 /* This flag tracks whether the HID device is usable for commands from 33 * userspace. The flag is already set before hid_add_device(), which 34 * runs in workqueue context, to allow hid_add_device() to communicate 35 * with userspace. 36 * However, if hid_add_device() fails, the flag is cleared without 37 * holding devlock. 38 * We guarantee that if @running changes from true to false while you're 39 * holding @devlock, it's still fine to access @hid. 40 */ 41 bool running; 42 43 __u8 *rd_data; 44 uint rd_size; 45 46 /* When this is NULL, userspace may use UHID_CREATE/UHID_CREATE2. */ 47 struct hid_device *hid; 48 struct uhid_event input_buf; 49 50 wait_queue_head_t waitq; 51 spinlock_t qlock; 52 __u8 head; 53 __u8 tail; 54 struct uhid_event *outq[UHID_BUFSIZE]; 55 56 /* blocking GET_REPORT support; state changes protected by qlock */ 57 struct mutex report_lock; 58 wait_queue_head_t report_wait; 59 bool report_running; 60 u32 report_id; 61 u32 report_type; 62 struct uhid_event report_buf; 63 struct work_struct worker; 64}; 65 66static struct miscdevice uhid_misc; 67 68static void uhid_device_add_worker(struct work_struct *work) 69{ 70 struct uhid_device *uhid = container_of(work, struct uhid_device, worker); 71 int ret; 72 73 ret = hid_add_device(uhid->hid); 74 if (ret) { 75 hid_err(uhid->hid, "Cannot register HID device: error %d\n", ret); 76 77 /* We used to call hid_destroy_device() here, but that's really 78 * messy to get right because we have to coordinate with 79 * concurrent writes from userspace that might be in the middle 80 * of using uhid->hid. 81 * Just leave uhid->hid as-is for now, and clean it up when 82 * userspace tries to close or reinitialize the uhid instance. 83 * 84 * However, we do have to clear the ->running flag and do a 85 * wakeup to make sure userspace knows that the device is gone. 86 */ 87 uhid->running = false; 88 wake_up_interruptible(&uhid->report_wait); 89 } 90} 91 92static void uhid_queue(struct uhid_device *uhid, struct uhid_event *ev) 93{ 94 __u8 newhead; 95 96 newhead = (uhid->head + 1) % UHID_BUFSIZE; 97 98 if (newhead != uhid->tail) { 99 uhid->outq[uhid->head] = ev; 100 uhid->head = newhead; 101 wake_up_interruptible(&uhid->waitq); 102 } else { 103 hid_warn(uhid->hid, "Output queue is full\n"); 104 kfree(ev); 105 } 106} 107 108static int uhid_queue_event(struct uhid_device *uhid, __u32 event) 109{ 110 unsigned long flags; 111 struct uhid_event *ev; 112 113 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 114 if (!ev) 115 return -ENOMEM; 116 117 ev->type = event; 118 119 spin_lock_irqsave(&uhid->qlock, flags); 120 uhid_queue(uhid, ev); 121 spin_unlock_irqrestore(&uhid->qlock, flags); 122 123 return 0; 124} 125 126static int uhid_hid_start(struct hid_device *hid) 127{ 128 struct uhid_device *uhid = hid->driver_data; 129 struct uhid_event *ev; 130 unsigned long flags; 131 132 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 133 if (!ev) 134 return -ENOMEM; 135 136 ev->type = UHID_START; 137 138 if (hid->report_enum[HID_FEATURE_REPORT].numbered) 139 ev->u.start.dev_flags |= UHID_DEV_NUMBERED_FEATURE_REPORTS; 140 if (hid->report_enum[HID_OUTPUT_REPORT].numbered) 141 ev->u.start.dev_flags |= UHID_DEV_NUMBERED_OUTPUT_REPORTS; 142 if (hid->report_enum[HID_INPUT_REPORT].numbered) 143 ev->u.start.dev_flags |= UHID_DEV_NUMBERED_INPUT_REPORTS; 144 145 spin_lock_irqsave(&uhid->qlock, flags); 146 uhid_queue(uhid, ev); 147 spin_unlock_irqrestore(&uhid->qlock, flags); 148 149 return 0; 150} 151 152static void uhid_hid_stop(struct hid_device *hid) 153{ 154 struct uhid_device *uhid = hid->driver_data; 155 156 hid->claimed = 0; 157 uhid_queue_event(uhid, UHID_STOP); 158} 159 160static int uhid_hid_open(struct hid_device *hid) 161{ 162 struct uhid_device *uhid = hid->driver_data; 163 164 return uhid_queue_event(uhid, UHID_OPEN); 165} 166 167static void uhid_hid_close(struct hid_device *hid) 168{ 169 struct uhid_device *uhid = hid->driver_data; 170 171 uhid_queue_event(uhid, UHID_CLOSE); 172} 173 174static int uhid_hid_parse(struct hid_device *hid) 175{ 176 struct uhid_device *uhid = hid->driver_data; 177 178 return hid_parse_report(hid, uhid->rd_data, uhid->rd_size); 179} 180 181/* must be called with report_lock held */ 182static int __uhid_report_queue_and_wait(struct uhid_device *uhid, 183 struct uhid_event *ev, 184 __u32 *report_id) 185{ 186 unsigned long flags; 187 int ret; 188 189 spin_lock_irqsave(&uhid->qlock, flags); 190 *report_id = ++uhid->report_id; 191 uhid->report_type = ev->type + 1; 192 uhid->report_running = true; 193 uhid_queue(uhid, ev); 194 spin_unlock_irqrestore(&uhid->qlock, flags); 195 196 ret = wait_event_interruptible_timeout(uhid->report_wait, 197 !uhid->report_running || !uhid->running, 198 5 * HZ); 199 if (!ret || !uhid->running || uhid->report_running) 200 ret = -EIO; 201 else if (ret < 0) 202 ret = -ERESTARTSYS; 203 else 204 ret = 0; 205 206 uhid->report_running = false; 207 208 return ret; 209} 210 211static void uhid_report_wake_up(struct uhid_device *uhid, u32 id, 212 const struct uhid_event *ev) 213{ 214 unsigned long flags; 215 216 spin_lock_irqsave(&uhid->qlock, flags); 217 218 /* id for old report; drop it silently */ 219 if (uhid->report_type != ev->type || uhid->report_id != id) 220 goto unlock; 221 if (!uhid->report_running) 222 goto unlock; 223 224 memcpy(&uhid->report_buf, ev, sizeof(*ev)); 225 uhid->report_running = false; 226 wake_up_interruptible(&uhid->report_wait); 227 228unlock: 229 spin_unlock_irqrestore(&uhid->qlock, flags); 230} 231 232static int uhid_hid_get_report(struct hid_device *hid, unsigned char rnum, 233 u8 *buf, size_t count, u8 rtype) 234{ 235 struct uhid_device *uhid = hid->driver_data; 236 struct uhid_get_report_reply_req *req; 237 struct uhid_event *ev; 238 int ret; 239 240 if (!uhid->running) 241 return -EIO; 242 243 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 244 if (!ev) 245 return -ENOMEM; 246 247 ev->type = UHID_GET_REPORT; 248 ev->u.get_report.rnum = rnum; 249 ev->u.get_report.rtype = rtype; 250 251 ret = mutex_lock_interruptible(&uhid->report_lock); 252 if (ret) { 253 kfree(ev); 254 return ret; 255 } 256 257 /* this _always_ takes ownership of @ev */ 258 ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.get_report.id); 259 if (ret) 260 goto unlock; 261 262 req = &uhid->report_buf.u.get_report_reply; 263 if (req->err) { 264 ret = -EIO; 265 } else { 266 ret = min3(count, (size_t)req->size, (size_t)UHID_DATA_MAX); 267 memcpy(buf, req->data, ret); 268 } 269 270unlock: 271 mutex_unlock(&uhid->report_lock); 272 return ret; 273} 274 275static int uhid_hid_set_report(struct hid_device *hid, unsigned char rnum, 276 const u8 *buf, size_t count, u8 rtype) 277{ 278 struct uhid_device *uhid = hid->driver_data; 279 struct uhid_event *ev; 280 int ret; 281 282 if (!uhid->running || count > UHID_DATA_MAX) 283 return -EIO; 284 285 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 286 if (!ev) 287 return -ENOMEM; 288 289 ev->type = UHID_SET_REPORT; 290 ev->u.set_report.rnum = rnum; 291 ev->u.set_report.rtype = rtype; 292 ev->u.set_report.size = count; 293 memcpy(ev->u.set_report.data, buf, count); 294 295 ret = mutex_lock_interruptible(&uhid->report_lock); 296 if (ret) { 297 kfree(ev); 298 return ret; 299 } 300 301 /* this _always_ takes ownership of @ev */ 302 ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.set_report.id); 303 if (ret) 304 goto unlock; 305 306 if (uhid->report_buf.u.set_report_reply.err) 307 ret = -EIO; 308 else 309 ret = count; 310 311unlock: 312 mutex_unlock(&uhid->report_lock); 313 return ret; 314} 315 316static int uhid_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 317 __u8 *buf, size_t len, unsigned char rtype, 318 int reqtype) 319{ 320 u8 u_rtype; 321 322 switch (rtype) { 323 case HID_FEATURE_REPORT: 324 u_rtype = UHID_FEATURE_REPORT; 325 break; 326 case HID_OUTPUT_REPORT: 327 u_rtype = UHID_OUTPUT_REPORT; 328 break; 329 case HID_INPUT_REPORT: 330 u_rtype = UHID_INPUT_REPORT; 331 break; 332 default: 333 return -EINVAL; 334 } 335 336 switch (reqtype) { 337 case HID_REQ_GET_REPORT: 338 return uhid_hid_get_report(hid, reportnum, buf, len, u_rtype); 339 case HID_REQ_SET_REPORT: 340 return uhid_hid_set_report(hid, reportnum, buf, len, u_rtype); 341 default: 342 return -EIO; 343 } 344} 345 346static int uhid_hid_output_raw(struct hid_device *hid, __u8 *buf, size_t count, 347 unsigned char report_type) 348{ 349 struct uhid_device *uhid = hid->driver_data; 350 __u8 rtype; 351 unsigned long flags; 352 struct uhid_event *ev; 353 354 switch (report_type) { 355 case HID_FEATURE_REPORT: 356 rtype = UHID_FEATURE_REPORT; 357 break; 358 case HID_OUTPUT_REPORT: 359 rtype = UHID_OUTPUT_REPORT; 360 break; 361 default: 362 return -EINVAL; 363 } 364 365 if (count < 1 || count > UHID_DATA_MAX) 366 return -EINVAL; 367 368 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 369 if (!ev) 370 return -ENOMEM; 371 372 ev->type = UHID_OUTPUT; 373 ev->u.output.size = count; 374 ev->u.output.rtype = rtype; 375 memcpy(ev->u.output.data, buf, count); 376 377 spin_lock_irqsave(&uhid->qlock, flags); 378 uhid_queue(uhid, ev); 379 spin_unlock_irqrestore(&uhid->qlock, flags); 380 381 return count; 382} 383 384static int uhid_hid_output_report(struct hid_device *hid, __u8 *buf, 385 size_t count) 386{ 387 return uhid_hid_output_raw(hid, buf, count, HID_OUTPUT_REPORT); 388} 389 390struct hid_ll_driver uhid_hid_driver = { 391 .start = uhid_hid_start, 392 .stop = uhid_hid_stop, 393 .open = uhid_hid_open, 394 .close = uhid_hid_close, 395 .parse = uhid_hid_parse, 396 .raw_request = uhid_hid_raw_request, 397 .output_report = uhid_hid_output_report, 398 .max_buffer_size = UHID_DATA_MAX, 399}; 400EXPORT_SYMBOL_GPL(uhid_hid_driver); 401 402#ifdef CONFIG_COMPAT 403 404/* Apparently we haven't stepped on these rakes enough times yet. */ 405struct uhid_create_req_compat { 406 __u8 name[128]; 407 __u8 phys[64]; 408 __u8 uniq[64]; 409 410 compat_uptr_t rd_data; 411 __u16 rd_size; 412 413 __u16 bus; 414 __u32 vendor; 415 __u32 product; 416 __u32 version; 417 __u32 country; 418} __attribute__((__packed__)); 419 420static int uhid_event_from_user(const char __user *buffer, size_t len, 421 struct uhid_event *event) 422{ 423 if (in_compat_syscall()) { 424 u32 type; 425 426 if (get_user(type, buffer)) 427 return -EFAULT; 428 429 if (type == UHID_CREATE) { 430 /* 431 * This is our messed up request with compat pointer. 432 * It is largish (more than 256 bytes) so we better 433 * allocate it from the heap. 434 */ 435 struct uhid_create_req_compat *compat; 436 437 compat = kzalloc(sizeof(*compat), GFP_KERNEL); 438 if (!compat) 439 return -ENOMEM; 440 441 buffer += sizeof(type); 442 len -= sizeof(type); 443 if (copy_from_user(compat, buffer, 444 min(len, sizeof(*compat)))) { 445 kfree(compat); 446 return -EFAULT; 447 } 448 449 /* Shuffle the data over to proper structure */ 450 event->type = type; 451 452 memcpy(event->u.create.name, compat->name, 453 sizeof(compat->name)); 454 memcpy(event->u.create.phys, compat->phys, 455 sizeof(compat->phys)); 456 memcpy(event->u.create.uniq, compat->uniq, 457 sizeof(compat->uniq)); 458 459 event->u.create.rd_data = compat_ptr(compat->rd_data); 460 event->u.create.rd_size = compat->rd_size; 461 462 event->u.create.bus = compat->bus; 463 event->u.create.vendor = compat->vendor; 464 event->u.create.product = compat->product; 465 event->u.create.version = compat->version; 466 event->u.create.country = compat->country; 467 468 kfree(compat); 469 return 0; 470 } 471 /* All others can be copied directly */ 472 } 473 474 if (copy_from_user(event, buffer, min(len, sizeof(*event)))) 475 return -EFAULT; 476 477 return 0; 478} 479#else 480static int uhid_event_from_user(const char __user *buffer, size_t len, 481 struct uhid_event *event) 482{ 483 if (copy_from_user(event, buffer, min(len, sizeof(*event)))) 484 return -EFAULT; 485 486 return 0; 487} 488#endif 489 490static int uhid_dev_create2(struct uhid_device *uhid, 491 const struct uhid_event *ev) 492{ 493 struct hid_device *hid; 494 size_t rd_size, len; 495 void *rd_data; 496 int ret; 497 498 if (uhid->hid) 499 return -EALREADY; 500 501 rd_size = ev->u.create2.rd_size; 502 if (rd_size <= 0 || rd_size > HID_MAX_DESCRIPTOR_SIZE) 503 return -EINVAL; 504 505 rd_data = kmemdup(ev->u.create2.rd_data, rd_size, GFP_KERNEL); 506 if (!rd_data) 507 return -ENOMEM; 508 509 uhid->rd_size = rd_size; 510 uhid->rd_data = rd_data; 511 512 hid = hid_allocate_device(); 513 if (IS_ERR(hid)) { 514 ret = PTR_ERR(hid); 515 goto err_free; 516 } 517 518 /* @hid is zero-initialized, strncpy() is correct, strlcpy() not */ 519 len = min(sizeof(hid->name), sizeof(ev->u.create2.name)) - 1; 520 strncpy(hid->name, ev->u.create2.name, len); 521 len = min(sizeof(hid->phys), sizeof(ev->u.create2.phys)) - 1; 522 strncpy(hid->phys, ev->u.create2.phys, len); 523 len = min(sizeof(hid->uniq), sizeof(ev->u.create2.uniq)) - 1; 524 strncpy(hid->uniq, ev->u.create2.uniq, len); 525 526 hid->ll_driver = &uhid_hid_driver; 527 hid->bus = ev->u.create2.bus; 528 hid->vendor = ev->u.create2.vendor; 529 hid->product = ev->u.create2.product; 530 hid->version = ev->u.create2.version; 531 hid->country = ev->u.create2.country; 532 hid->driver_data = uhid; 533 hid->dev.parent = uhid_misc.this_device; 534 535 uhid->hid = hid; 536 uhid->running = true; 537 538 /* Adding of a HID device is done through a worker, to allow HID drivers 539 * which use feature requests during .probe to work, without they would 540 * be blocked on devlock, which is held by uhid_char_write. 541 */ 542 schedule_work(&uhid->worker); 543 544 return 0; 545 546err_free: 547 kfree(uhid->rd_data); 548 uhid->rd_data = NULL; 549 uhid->rd_size = 0; 550 return ret; 551} 552 553static int uhid_dev_create(struct uhid_device *uhid, 554 struct uhid_event *ev) 555{ 556 struct uhid_create_req orig; 557 558 orig = ev->u.create; 559 560 if (orig.rd_size <= 0 || orig.rd_size > HID_MAX_DESCRIPTOR_SIZE) 561 return -EINVAL; 562 if (copy_from_user(&ev->u.create2.rd_data, orig.rd_data, orig.rd_size)) 563 return -EFAULT; 564 565 memcpy(ev->u.create2.name, orig.name, sizeof(orig.name)); 566 memcpy(ev->u.create2.phys, orig.phys, sizeof(orig.phys)); 567 memcpy(ev->u.create2.uniq, orig.uniq, sizeof(orig.uniq)); 568 ev->u.create2.rd_size = orig.rd_size; 569 ev->u.create2.bus = orig.bus; 570 ev->u.create2.vendor = orig.vendor; 571 ev->u.create2.product = orig.product; 572 ev->u.create2.version = orig.version; 573 ev->u.create2.country = orig.country; 574 575 return uhid_dev_create2(uhid, ev); 576} 577 578static int uhid_dev_destroy(struct uhid_device *uhid) 579{ 580 if (!uhid->hid) 581 return -EINVAL; 582 583 uhid->running = false; 584 wake_up_interruptible(&uhid->report_wait); 585 586 cancel_work_sync(&uhid->worker); 587 588 hid_destroy_device(uhid->hid); 589 uhid->hid = NULL; 590 kfree(uhid->rd_data); 591 592 return 0; 593} 594 595static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev) 596{ 597 if (!uhid->running) 598 return -EINVAL; 599 600 hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data, 601 min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0); 602 603 return 0; 604} 605 606static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev) 607{ 608 if (!uhid->running) 609 return -EINVAL; 610 611 hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data, 612 min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0); 613 614 return 0; 615} 616 617static int uhid_dev_get_report_reply(struct uhid_device *uhid, 618 struct uhid_event *ev) 619{ 620 if (!uhid->running) 621 return -EINVAL; 622 623 uhid_report_wake_up(uhid, ev->u.get_report_reply.id, ev); 624 return 0; 625} 626 627static int uhid_dev_set_report_reply(struct uhid_device *uhid, 628 struct uhid_event *ev) 629{ 630 if (!uhid->running) 631 return -EINVAL; 632 633 uhid_report_wake_up(uhid, ev->u.set_report_reply.id, ev); 634 return 0; 635} 636 637static int uhid_char_open(struct inode *inode, struct file *file) 638{ 639 struct uhid_device *uhid; 640 641 uhid = kzalloc(sizeof(*uhid), GFP_KERNEL); 642 if (!uhid) 643 return -ENOMEM; 644 645 mutex_init(&uhid->devlock); 646 mutex_init(&uhid->report_lock); 647 spin_lock_init(&uhid->qlock); 648 init_waitqueue_head(&uhid->waitq); 649 init_waitqueue_head(&uhid->report_wait); 650 uhid->running = false; 651 INIT_WORK(&uhid->worker, uhid_device_add_worker); 652 653 file->private_data = uhid; 654 stream_open(inode, file); 655 656 return 0; 657} 658 659static int uhid_char_release(struct inode *inode, struct file *file) 660{ 661 struct uhid_device *uhid = file->private_data; 662 unsigned int i; 663 664 uhid_dev_destroy(uhid); 665 666 for (i = 0; i < UHID_BUFSIZE; ++i) 667 kfree(uhid->outq[i]); 668 669 kfree(uhid); 670 671 return 0; 672} 673 674static ssize_t uhid_char_read(struct file *file, char __user *buffer, 675 size_t count, loff_t *ppos) 676{ 677 struct uhid_device *uhid = file->private_data; 678 int ret; 679 unsigned long flags; 680 size_t len; 681 682 /* they need at least the "type" member of uhid_event */ 683 if (count < sizeof(__u32)) 684 return -EINVAL; 685 686try_again: 687 if (file->f_flags & O_NONBLOCK) { 688 if (uhid->head == uhid->tail) 689 return -EAGAIN; 690 } else { 691 ret = wait_event_interruptible(uhid->waitq, 692 uhid->head != uhid->tail); 693 if (ret) 694 return ret; 695 } 696 697 ret = mutex_lock_interruptible(&uhid->devlock); 698 if (ret) 699 return ret; 700 701 if (uhid->head == uhid->tail) { 702 mutex_unlock(&uhid->devlock); 703 goto try_again; 704 } else { 705 len = min(count, sizeof(**uhid->outq)); 706 if (copy_to_user(buffer, uhid->outq[uhid->tail], len)) { 707 ret = -EFAULT; 708 } else { 709 kfree(uhid->outq[uhid->tail]); 710 uhid->outq[uhid->tail] = NULL; 711 712 spin_lock_irqsave(&uhid->qlock, flags); 713 uhid->tail = (uhid->tail + 1) % UHID_BUFSIZE; 714 spin_unlock_irqrestore(&uhid->qlock, flags); 715 } 716 } 717 718 mutex_unlock(&uhid->devlock); 719 return ret ? ret : len; 720} 721 722static ssize_t uhid_char_write(struct file *file, const char __user *buffer, 723 size_t count, loff_t *ppos) 724{ 725 struct uhid_device *uhid = file->private_data; 726 int ret; 727 size_t len; 728 729 /* we need at least the "type" member of uhid_event */ 730 if (count < sizeof(__u32)) 731 return -EINVAL; 732 733 ret = mutex_lock_interruptible(&uhid->devlock); 734 if (ret) 735 return ret; 736 737 memset(&uhid->input_buf, 0, sizeof(uhid->input_buf)); 738 len = min(count, sizeof(uhid->input_buf)); 739 740 ret = uhid_event_from_user(buffer, len, &uhid->input_buf); 741 if (ret) 742 goto unlock; 743 744 switch (uhid->input_buf.type) { 745 case UHID_CREATE: 746 /* 747 * 'struct uhid_create_req' contains a __user pointer which is 748 * copied from, so it's unsafe to allow this with elevated 749 * privileges (e.g. from a setuid binary) or via kernel_write(). 750 */ 751 if (file->f_cred != current_cred() || uaccess_kernel()) { 752 pr_err_once("UHID_CREATE from different security context by process %d (%s), this is not allowed.\n", 753 task_tgid_vnr(current), current->comm); 754 ret = -EACCES; 755 goto unlock; 756 } 757 ret = uhid_dev_create(uhid, &uhid->input_buf); 758 break; 759 case UHID_CREATE2: 760 ret = uhid_dev_create2(uhid, &uhid->input_buf); 761 break; 762 case UHID_DESTROY: 763 ret = uhid_dev_destroy(uhid); 764 break; 765 case UHID_INPUT: 766 ret = uhid_dev_input(uhid, &uhid->input_buf); 767 break; 768 case UHID_INPUT2: 769 ret = uhid_dev_input2(uhid, &uhid->input_buf); 770 break; 771 case UHID_GET_REPORT_REPLY: 772 ret = uhid_dev_get_report_reply(uhid, &uhid->input_buf); 773 break; 774 case UHID_SET_REPORT_REPLY: 775 ret = uhid_dev_set_report_reply(uhid, &uhid->input_buf); 776 break; 777 default: 778 ret = -EOPNOTSUPP; 779 } 780 781unlock: 782 mutex_unlock(&uhid->devlock); 783 784 /* return "count" not "len" to not confuse the caller */ 785 return ret ? ret : count; 786} 787 788static __poll_t uhid_char_poll(struct file *file, poll_table *wait) 789{ 790 struct uhid_device *uhid = file->private_data; 791 __poll_t mask = EPOLLOUT | EPOLLWRNORM; /* uhid is always writable */ 792 793 poll_wait(file, &uhid->waitq, wait); 794 795 if (uhid->head != uhid->tail) 796 mask |= EPOLLIN | EPOLLRDNORM; 797 798 return mask; 799} 800 801static const struct file_operations uhid_fops = { 802 .owner = THIS_MODULE, 803 .open = uhid_char_open, 804 .release = uhid_char_release, 805 .read = uhid_char_read, 806 .write = uhid_char_write, 807 .poll = uhid_char_poll, 808 .llseek = no_llseek, 809}; 810 811static struct miscdevice uhid_misc = { 812 .fops = &uhid_fops, 813 .minor = UHID_MINOR, 814 .name = UHID_NAME, 815}; 816module_misc_device(uhid_misc); 817 818MODULE_LICENSE("GPL"); 819MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>"); 820MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem"); 821MODULE_ALIAS_MISCDEV(UHID_MINOR); 822MODULE_ALIAS("devname:" UHID_NAME); 823