1 /* 2 * f_fs.c -- user mode file system API for USB composite function controllers 3 * 4 * Copyright (C) 2010 Samsung Electronics 5 * Author: Michal Nazarewicz <mina86@mina86.com> 6 * 7 * Based on inode.c (GadgetFS) which was: 8 * Copyright (C) 2003-2004 David Brownell 9 * Copyright (C) 2003 Agilent Technologies 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 */ 16 17 18 /* #define DEBUG */ 19 /* #define VERBOSE_DEBUG */ 20 21 #include <linux/blkdev.h> 22 #include <linux/pagemap.h> 23 #include <linux/export.h> 24 #include <linux/hid.h> 25 #include <linux/module.h> 26 #include <linux/uio.h> 27 #include <asm/unaligned.h> 28 29 #include <linux/usb/composite.h> 30 #include <linux/usb/functionfs.h> 31 32 #include <linux/aio.h> 33 #include <linux/mmu_context.h> 34 #include <linux/poll.h> 35 #include <linux/eventfd.h> 36 37 #include "u_fs.h" 38 #include "u_f.h" 39 #include "u_os_desc.h" 40 #include "configfs.h" 41 42 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ 43 44 /* Reference counter handling */ 45 static void ffs_data_get(struct ffs_data *ffs); 46 static void ffs_data_put(struct ffs_data *ffs); 47 /* Creates new ffs_data object. */ 48 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc)); 49 50 /* Opened counter handling. */ 51 static void ffs_data_opened(struct ffs_data *ffs); 52 static void ffs_data_closed(struct ffs_data *ffs); 53 54 /* Called with ffs->mutex held; take over ownership of data. */ 55 static int __must_check 56 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len); 57 static int __must_check 58 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len); 59 60 61 /* The function structure ***************************************************/ 62 63 struct ffs_ep; 64 65 struct ffs_function { 66 struct usb_configuration *conf; 67 struct usb_gadget *gadget; 68 struct ffs_data *ffs; 69 70 struct ffs_ep *eps; 71 u8 eps_revmap[16]; 72 short *interfaces_nums; 73 74 struct usb_function function; 75 }; 76 77 78 static struct ffs_function *ffs_func_from_usb(struct usb_function *f) 79 { 80 return container_of(f, struct ffs_function, function); 81 } 82 83 84 static inline enum ffs_setup_state 85 ffs_setup_state_clear_cancelled(struct ffs_data *ffs) 86 { 87 return (enum ffs_setup_state) 88 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP); 89 } 90 91 92 static void ffs_func_eps_disable(struct ffs_function *func); 93 static int __must_check ffs_func_eps_enable(struct ffs_function *func); 94 95 static int ffs_func_bind(struct usb_configuration *, 96 struct usb_function *); 97 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned); 98 static void ffs_func_disable(struct usb_function *); 99 static int ffs_func_setup(struct usb_function *, 100 const struct usb_ctrlrequest *); 101 static void ffs_func_suspend(struct usb_function *); 102 static void ffs_func_resume(struct usb_function *); 103 104 105 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num); 106 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf); 107 108 109 /* The endpoints structures *************************************************/ 110 111 struct ffs_ep { 112 struct usb_ep *ep; /* P: ffs->eps_lock */ 113 struct usb_request *req; /* P: epfile->mutex */ 114 115 /* [0]: full speed, [1]: high speed, [2]: super speed */ 116 struct usb_endpoint_descriptor *descs[3]; 117 118 u8 num; 119 120 int status; /* P: epfile->mutex */ 121 }; 122 123 struct ffs_epfile { 124 /* Protects ep->ep and ep->req. */ 125 struct mutex mutex; 126 wait_queue_head_t wait; 127 128 struct ffs_data *ffs; 129 struct ffs_ep *ep; /* P: ffs->eps_lock */ 130 131 struct dentry *dentry; 132 133 char name[5]; 134 135 unsigned char in; /* P: ffs->eps_lock */ 136 unsigned char isoc; /* P: ffs->eps_lock */ 137 138 unsigned char _pad; 139 }; 140 141 /* ffs_io_data structure ***************************************************/ 142 143 struct ffs_io_data { 144 bool aio; 145 bool read; 146 147 struct kiocb *kiocb; 148 struct iov_iter data; 149 const void *to_free; 150 char *buf; 151 152 struct mm_struct *mm; 153 struct work_struct work; 154 155 struct usb_ep *ep; 156 struct usb_request *req; 157 158 struct ffs_data *ffs; 159 }; 160 161 struct ffs_desc_helper { 162 struct ffs_data *ffs; 163 unsigned interfaces_count; 164 unsigned eps_count; 165 }; 166 167 static int __must_check ffs_epfiles_create(struct ffs_data *ffs); 168 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count); 169 170 static struct dentry * 171 ffs_sb_create_file(struct super_block *sb, const char *name, void *data, 172 const struct file_operations *fops); 173 174 /* Devices management *******************************************************/ 175 176 DEFINE_MUTEX(ffs_lock); 177 EXPORT_SYMBOL_GPL(ffs_lock); 178 179 static struct ffs_dev *_ffs_find_dev(const char *name); 180 static struct ffs_dev *_ffs_alloc_dev(void); 181 static int _ffs_name_dev(struct ffs_dev *dev, const char *name); 182 static void _ffs_free_dev(struct ffs_dev *dev); 183 static void *ffs_acquire_dev(const char *dev_name); 184 static void ffs_release_dev(struct ffs_data *ffs_data); 185 static int ffs_ready(struct ffs_data *ffs); 186 static void ffs_closed(struct ffs_data *ffs); 187 188 /* Misc helper functions ****************************************************/ 189 190 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 191 __attribute__((warn_unused_result, nonnull)); 192 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 193 __attribute__((warn_unused_result, nonnull)); 194 195 196 /* Control file aka ep0 *****************************************************/ 197 198 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req) 199 { 200 struct ffs_data *ffs = req->context; 201 202 complete_all(&ffs->ep0req_completion); 203 } 204 205 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len) 206 { 207 struct usb_request *req = ffs->ep0req; 208 int ret; 209 210 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength); 211 212 spin_unlock_irq(&ffs->ev.waitq.lock); 213 214 req->buf = data; 215 req->length = len; 216 217 /* 218 * UDC layer requires to provide a buffer even for ZLP, but should 219 * not use it at all. Let's provide some poisoned pointer to catch 220 * possible bug in the driver. 221 */ 222 if (req->buf == NULL) 223 req->buf = (void *)0xDEADBABE; 224 225 reinit_completion(&ffs->ep0req_completion); 226 227 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC); 228 if (unlikely(ret < 0)) 229 return ret; 230 231 ret = wait_for_completion_interruptible(&ffs->ep0req_completion); 232 if (unlikely(ret)) { 233 usb_ep_dequeue(ffs->gadget->ep0, req); 234 return -EINTR; 235 } 236 237 ffs->setup_state = FFS_NO_SETUP; 238 return req->status ? req->status : req->actual; 239 } 240 241 static int __ffs_ep0_stall(struct ffs_data *ffs) 242 { 243 if (ffs->ev.can_stall) { 244 pr_vdebug("ep0 stall\n"); 245 usb_ep_set_halt(ffs->gadget->ep0); 246 ffs->setup_state = FFS_NO_SETUP; 247 return -EL2HLT; 248 } else { 249 pr_debug("bogus ep0 stall!\n"); 250 return -ESRCH; 251 } 252 } 253 254 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, 255 size_t len, loff_t *ptr) 256 { 257 struct ffs_data *ffs = file->private_data; 258 ssize_t ret; 259 char *data; 260 261 ENTER(); 262 263 /* Fast check if setup was canceled */ 264 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 265 return -EIDRM; 266 267 /* Acquire mutex */ 268 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 269 if (unlikely(ret < 0)) 270 return ret; 271 272 /* Check state */ 273 switch (ffs->state) { 274 case FFS_READ_DESCRIPTORS: 275 case FFS_READ_STRINGS: 276 /* Copy data */ 277 if (unlikely(len < 16)) { 278 ret = -EINVAL; 279 break; 280 } 281 282 data = ffs_prepare_buffer(buf, len); 283 if (IS_ERR(data)) { 284 ret = PTR_ERR(data); 285 break; 286 } 287 288 /* Handle data */ 289 if (ffs->state == FFS_READ_DESCRIPTORS) { 290 pr_info("read descriptors\n"); 291 ret = __ffs_data_got_descs(ffs, data, len); 292 if (unlikely(ret < 0)) 293 break; 294 295 ffs->state = FFS_READ_STRINGS; 296 ret = len; 297 } else { 298 pr_info("read strings\n"); 299 ret = __ffs_data_got_strings(ffs, data, len); 300 if (unlikely(ret < 0)) 301 break; 302 303 ret = ffs_epfiles_create(ffs); 304 if (unlikely(ret)) { 305 ffs->state = FFS_CLOSING; 306 break; 307 } 308 309 ffs->state = FFS_ACTIVE; 310 mutex_unlock(&ffs->mutex); 311 312 ret = ffs_ready(ffs); 313 if (unlikely(ret < 0)) { 314 ffs->state = FFS_CLOSING; 315 return ret; 316 } 317 318 return len; 319 } 320 break; 321 322 case FFS_ACTIVE: 323 data = NULL; 324 /* 325 * We're called from user space, we can use _irq 326 * rather then _irqsave 327 */ 328 spin_lock_irq(&ffs->ev.waitq.lock); 329 switch (ffs_setup_state_clear_cancelled(ffs)) { 330 case FFS_SETUP_CANCELLED: 331 ret = -EIDRM; 332 goto done_spin; 333 334 case FFS_NO_SETUP: 335 ret = -ESRCH; 336 goto done_spin; 337 338 case FFS_SETUP_PENDING: 339 break; 340 } 341 342 /* FFS_SETUP_PENDING */ 343 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) { 344 spin_unlock_irq(&ffs->ev.waitq.lock); 345 ret = __ffs_ep0_stall(ffs); 346 break; 347 } 348 349 /* FFS_SETUP_PENDING and not stall */ 350 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); 351 352 spin_unlock_irq(&ffs->ev.waitq.lock); 353 354 data = ffs_prepare_buffer(buf, len); 355 if (IS_ERR(data)) { 356 ret = PTR_ERR(data); 357 break; 358 } 359 360 spin_lock_irq(&ffs->ev.waitq.lock); 361 362 /* 363 * We are guaranteed to be still in FFS_ACTIVE state 364 * but the state of setup could have changed from 365 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need 366 * to check for that. If that happened we copied data 367 * from user space in vain but it's unlikely. 368 * 369 * For sure we are not in FFS_NO_SETUP since this is 370 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP 371 * transition can be performed and it's protected by 372 * mutex. 373 */ 374 if (ffs_setup_state_clear_cancelled(ffs) == 375 FFS_SETUP_CANCELLED) { 376 ret = -EIDRM; 377 done_spin: 378 spin_unlock_irq(&ffs->ev.waitq.lock); 379 } else { 380 /* unlocks spinlock */ 381 ret = __ffs_ep0_queue_wait(ffs, data, len); 382 } 383 kfree(data); 384 break; 385 386 default: 387 ret = -EBADFD; 388 break; 389 } 390 391 mutex_unlock(&ffs->mutex); 392 return ret; 393 } 394 395 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */ 396 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf, 397 size_t n) 398 { 399 /* 400 * n cannot be bigger than ffs->ev.count, which cannot be bigger than 401 * size of ffs->ev.types array (which is four) so that's how much space 402 * we reserve. 403 */ 404 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)]; 405 const size_t size = n * sizeof *events; 406 unsigned i = 0; 407 408 memset(events, 0, size); 409 410 do { 411 events[i].type = ffs->ev.types[i]; 412 if (events[i].type == FUNCTIONFS_SETUP) { 413 events[i].u.setup = ffs->ev.setup; 414 ffs->setup_state = FFS_SETUP_PENDING; 415 } 416 } while (++i < n); 417 418 ffs->ev.count -= n; 419 if (ffs->ev.count) 420 memmove(ffs->ev.types, ffs->ev.types + n, 421 ffs->ev.count * sizeof *ffs->ev.types); 422 423 spin_unlock_irq(&ffs->ev.waitq.lock); 424 mutex_unlock(&ffs->mutex); 425 426 return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size; 427 } 428 429 static ssize_t ffs_ep0_read(struct file *file, char __user *buf, 430 size_t len, loff_t *ptr) 431 { 432 struct ffs_data *ffs = file->private_data; 433 char *data = NULL; 434 size_t n; 435 int ret; 436 437 ENTER(); 438 439 /* Fast check if setup was canceled */ 440 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 441 return -EIDRM; 442 443 /* Acquire mutex */ 444 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 445 if (unlikely(ret < 0)) 446 return ret; 447 448 /* Check state */ 449 if (ffs->state != FFS_ACTIVE) { 450 ret = -EBADFD; 451 goto done_mutex; 452 } 453 454 /* 455 * We're called from user space, we can use _irq rather then 456 * _irqsave 457 */ 458 spin_lock_irq(&ffs->ev.waitq.lock); 459 460 switch (ffs_setup_state_clear_cancelled(ffs)) { 461 case FFS_SETUP_CANCELLED: 462 ret = -EIDRM; 463 break; 464 465 case FFS_NO_SETUP: 466 n = len / sizeof(struct usb_functionfs_event); 467 if (unlikely(!n)) { 468 ret = -EINVAL; 469 break; 470 } 471 472 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) { 473 ret = -EAGAIN; 474 break; 475 } 476 477 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, 478 ffs->ev.count)) { 479 ret = -EINTR; 480 break; 481 } 482 483 return __ffs_ep0_read_events(ffs, buf, 484 min(n, (size_t)ffs->ev.count)); 485 486 case FFS_SETUP_PENDING: 487 if (ffs->ev.setup.bRequestType & USB_DIR_IN) { 488 spin_unlock_irq(&ffs->ev.waitq.lock); 489 ret = __ffs_ep0_stall(ffs); 490 goto done_mutex; 491 } 492 493 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); 494 495 spin_unlock_irq(&ffs->ev.waitq.lock); 496 497 if (likely(len)) { 498 data = kmalloc(len, GFP_KERNEL); 499 if (unlikely(!data)) { 500 ret = -ENOMEM; 501 goto done_mutex; 502 } 503 } 504 505 spin_lock_irq(&ffs->ev.waitq.lock); 506 507 /* See ffs_ep0_write() */ 508 if (ffs_setup_state_clear_cancelled(ffs) == 509 FFS_SETUP_CANCELLED) { 510 ret = -EIDRM; 511 break; 512 } 513 514 /* unlocks spinlock */ 515 ret = __ffs_ep0_queue_wait(ffs, data, len); 516 if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len))) 517 ret = -EFAULT; 518 goto done_mutex; 519 520 default: 521 ret = -EBADFD; 522 break; 523 } 524 525 spin_unlock_irq(&ffs->ev.waitq.lock); 526 done_mutex: 527 mutex_unlock(&ffs->mutex); 528 kfree(data); 529 return ret; 530 } 531 532 static int ffs_ep0_open(struct inode *inode, struct file *file) 533 { 534 struct ffs_data *ffs = inode->i_private; 535 536 ENTER(); 537 538 if (unlikely(ffs->state == FFS_CLOSING)) 539 return -EBUSY; 540 541 file->private_data = ffs; 542 ffs_data_opened(ffs); 543 544 return 0; 545 } 546 547 static int ffs_ep0_release(struct inode *inode, struct file *file) 548 { 549 struct ffs_data *ffs = file->private_data; 550 551 ENTER(); 552 553 ffs_data_closed(ffs); 554 555 return 0; 556 } 557 558 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) 559 { 560 struct ffs_data *ffs = file->private_data; 561 struct usb_gadget *gadget = ffs->gadget; 562 long ret; 563 564 ENTER(); 565 566 if (code == FUNCTIONFS_INTERFACE_REVMAP) { 567 struct ffs_function *func = ffs->func; 568 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV; 569 } else if (gadget && gadget->ops->ioctl) { 570 ret = gadget->ops->ioctl(gadget, code, value); 571 } else { 572 ret = -ENOTTY; 573 } 574 575 return ret; 576 } 577 578 static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait) 579 { 580 struct ffs_data *ffs = file->private_data; 581 unsigned int mask = POLLWRNORM; 582 int ret; 583 584 poll_wait(file, &ffs->ev.waitq, wait); 585 586 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 587 if (unlikely(ret < 0)) 588 return mask; 589 590 switch (ffs->state) { 591 case FFS_READ_DESCRIPTORS: 592 case FFS_READ_STRINGS: 593 mask |= POLLOUT; 594 break; 595 596 case FFS_ACTIVE: 597 switch (ffs->setup_state) { 598 case FFS_NO_SETUP: 599 if (ffs->ev.count) 600 mask |= POLLIN; 601 break; 602 603 case FFS_SETUP_PENDING: 604 case FFS_SETUP_CANCELLED: 605 mask |= (POLLIN | POLLOUT); 606 break; 607 } 608 case FFS_CLOSING: 609 break; 610 case FFS_DEACTIVATED: 611 break; 612 } 613 614 mutex_unlock(&ffs->mutex); 615 616 return mask; 617 } 618 619 static const struct file_operations ffs_ep0_operations = { 620 .llseek = no_llseek, 621 622 .open = ffs_ep0_open, 623 .write = ffs_ep0_write, 624 .read = ffs_ep0_read, 625 .release = ffs_ep0_release, 626 .unlocked_ioctl = ffs_ep0_ioctl, 627 .poll = ffs_ep0_poll, 628 }; 629 630 631 /* "Normal" endpoints operations ********************************************/ 632 633 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) 634 { 635 ENTER(); 636 if (likely(req->context)) { 637 struct ffs_ep *ep = _ep->driver_data; 638 ep->status = req->status ? req->status : req->actual; 639 complete(req->context); 640 } 641 } 642 643 static void ffs_user_copy_worker(struct work_struct *work) 644 { 645 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data, 646 work); 647 int ret = io_data->req->status ? io_data->req->status : 648 io_data->req->actual; 649 650 if (io_data->read && ret > 0) { 651 use_mm(io_data->mm); 652 ret = copy_to_iter(io_data->buf, ret, &io_data->data); 653 if (iov_iter_count(&io_data->data)) 654 ret = -EFAULT; 655 unuse_mm(io_data->mm); 656 } 657 658 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret); 659 660 if (io_data->ffs->ffs_eventfd && 661 !(io_data->kiocb->ki_flags & IOCB_EVENTFD)) 662 eventfd_signal(io_data->ffs->ffs_eventfd, 1); 663 664 usb_ep_free_request(io_data->ep, io_data->req); 665 666 io_data->kiocb->private = NULL; 667 if (io_data->read) 668 kfree(io_data->to_free); 669 kfree(io_data->buf); 670 kfree(io_data); 671 } 672 673 static void ffs_epfile_async_io_complete(struct usb_ep *_ep, 674 struct usb_request *req) 675 { 676 struct ffs_io_data *io_data = req->context; 677 678 ENTER(); 679 680 INIT_WORK(&io_data->work, ffs_user_copy_worker); 681 schedule_work(&io_data->work); 682 } 683 684 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) 685 { 686 struct ffs_epfile *epfile = file->private_data; 687 struct usb_request *req; 688 struct ffs_ep *ep; 689 char *data = NULL; 690 ssize_t ret, data_len = -EINVAL; 691 int halt; 692 693 /* Are we still active? */ 694 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 695 return -ENODEV; 696 697 /* Wait for endpoint to be enabled */ 698 ep = epfile->ep; 699 if (!ep) { 700 if (file->f_flags & O_NONBLOCK) 701 return -EAGAIN; 702 703 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep)); 704 if (ret) 705 return -EINTR; 706 } 707 708 /* Do we halt? */ 709 halt = (!io_data->read == !epfile->in); 710 if (halt && epfile->isoc) 711 return -EINVAL; 712 713 /* Allocate & copy */ 714 if (!halt) { 715 /* 716 * if we _do_ wait above, the epfile->ffs->gadget might be NULL 717 * before the waiting completes, so do not assign to 'gadget' 718 * earlier 719 */ 720 struct usb_gadget *gadget = epfile->ffs->gadget; 721 size_t copied; 722 723 spin_lock_irq(&epfile->ffs->eps_lock); 724 /* In the meantime, endpoint got disabled or changed. */ 725 if (epfile->ep != ep) { 726 spin_unlock_irq(&epfile->ffs->eps_lock); 727 return -ESHUTDOWN; 728 } 729 data_len = iov_iter_count(&io_data->data); 730 /* 731 * Controller may require buffer size to be aligned to 732 * maxpacketsize of an out endpoint. 733 */ 734 if (io_data->read) 735 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len); 736 spin_unlock_irq(&epfile->ffs->eps_lock); 737 738 data = kmalloc(data_len, GFP_KERNEL); 739 if (unlikely(!data)) 740 return -ENOMEM; 741 if (!io_data->read) { 742 copied = copy_from_iter(data, data_len, &io_data->data); 743 if (copied != data_len) { 744 ret = -EFAULT; 745 goto error; 746 } 747 } 748 } 749 750 /* We will be using request */ 751 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK); 752 if (unlikely(ret)) 753 goto error; 754 755 spin_lock_irq(&epfile->ffs->eps_lock); 756 757 if (epfile->ep != ep) { 758 /* In the meantime, endpoint got disabled or changed. */ 759 ret = -ESHUTDOWN; 760 } else if (halt) { 761 /* Halt */ 762 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep)) 763 usb_ep_set_halt(ep->ep); 764 ret = -EBADMSG; 765 } else if (unlikely(data_len == -EINVAL)) { 766 /* 767 * Sanity Check: even though data_len can't be used 768 * uninitialized at the time I write this comment, some 769 * compilers complain about this situation. 770 * In order to keep the code clean from warnings, data_len is 771 * being initialized to -EINVAL during its declaration, which 772 * means we can't rely on compiler anymore to warn no future 773 * changes won't result in data_len being used uninitialized. 774 * For such reason, we're adding this redundant sanity check 775 * here. 776 */ 777 WARN(1, "%s: data_len == -EINVAL\n", __func__); 778 ret = -EINVAL; 779 } else if (!io_data->aio) { 780 DECLARE_COMPLETION_ONSTACK(done); 781 bool interrupted = false; 782 783 req = ep->req; 784 req->buf = data; 785 req->length = data_len; 786 787 req->context = &done; 788 req->complete = ffs_epfile_io_complete; 789 790 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 791 if (unlikely(ret < 0)) 792 goto error_lock; 793 794 spin_unlock_irq(&epfile->ffs->eps_lock); 795 796 if (unlikely(wait_for_completion_interruptible(&done))) { 797 /* 798 * To avoid race condition with ffs_epfile_io_complete, 799 * dequeue the request first then check 800 * status. usb_ep_dequeue API should guarantee no race 801 * condition with req->complete callback. 802 */ 803 usb_ep_dequeue(ep->ep, req); 804 interrupted = ep->status < 0; 805 } 806 807 /* 808 * XXX We may end up silently droping data here. Since data_len 809 * (i.e. req->length) may be bigger than len (after being 810 * rounded up to maxpacketsize), we may end up with more data 811 * then user space has space for. 812 */ 813 ret = interrupted ? -EINTR : ep->status; 814 if (io_data->read && ret > 0) { 815 ret = copy_to_iter(data, ret, &io_data->data); 816 if (!ret) 817 ret = -EFAULT; 818 } 819 goto error_mutex; 820 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_KERNEL))) { 821 ret = -ENOMEM; 822 } else { 823 req->buf = data; 824 req->length = data_len; 825 826 io_data->buf = data; 827 io_data->ep = ep->ep; 828 io_data->req = req; 829 io_data->ffs = epfile->ffs; 830 831 req->context = io_data; 832 req->complete = ffs_epfile_async_io_complete; 833 834 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 835 if (unlikely(ret)) { 836 usb_ep_free_request(ep->ep, req); 837 goto error_lock; 838 } 839 840 ret = -EIOCBQUEUED; 841 /* 842 * Do not kfree the buffer in this function. It will be freed 843 * by ffs_user_copy_worker. 844 */ 845 data = NULL; 846 } 847 848 error_lock: 849 spin_unlock_irq(&epfile->ffs->eps_lock); 850 error_mutex: 851 mutex_unlock(&epfile->mutex); 852 error: 853 kfree(data); 854 return ret; 855 } 856 857 static int 858 ffs_epfile_open(struct inode *inode, struct file *file) 859 { 860 struct ffs_epfile *epfile = inode->i_private; 861 862 ENTER(); 863 864 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 865 return -ENODEV; 866 867 file->private_data = epfile; 868 ffs_data_opened(epfile->ffs); 869 870 return 0; 871 } 872 873 static int ffs_aio_cancel(struct kiocb *kiocb) 874 { 875 struct ffs_io_data *io_data = kiocb->private; 876 struct ffs_epfile *epfile = kiocb->ki_filp->private_data; 877 int value; 878 879 ENTER(); 880 881 spin_lock_irq(&epfile->ffs->eps_lock); 882 883 if (likely(io_data && io_data->ep && io_data->req)) 884 value = usb_ep_dequeue(io_data->ep, io_data->req); 885 else 886 value = -EINVAL; 887 888 spin_unlock_irq(&epfile->ffs->eps_lock); 889 890 return value; 891 } 892 893 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from) 894 { 895 struct ffs_io_data io_data, *p = &io_data; 896 ssize_t res; 897 898 ENTER(); 899 900 if (!is_sync_kiocb(kiocb)) { 901 p = kmalloc(sizeof(io_data), GFP_KERNEL); 902 if (unlikely(!p)) 903 return -ENOMEM; 904 p->aio = true; 905 } else { 906 p->aio = false; 907 } 908 909 p->read = false; 910 p->kiocb = kiocb; 911 p->data = *from; 912 p->mm = current->mm; 913 914 kiocb->private = p; 915 916 if (p->aio) 917 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 918 919 res = ffs_epfile_io(kiocb->ki_filp, p); 920 if (res == -EIOCBQUEUED) 921 return res; 922 if (p->aio) 923 kfree(p); 924 else 925 *from = p->data; 926 return res; 927 } 928 929 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) 930 { 931 struct ffs_io_data io_data, *p = &io_data; 932 ssize_t res; 933 934 ENTER(); 935 936 if (!is_sync_kiocb(kiocb)) { 937 p = kmalloc(sizeof(io_data), GFP_KERNEL); 938 if (unlikely(!p)) 939 return -ENOMEM; 940 p->aio = true; 941 } else { 942 p->aio = false; 943 } 944 945 p->read = true; 946 p->kiocb = kiocb; 947 if (p->aio) { 948 p->to_free = dup_iter(&p->data, to, GFP_KERNEL); 949 if (!p->to_free) { 950 kfree(p); 951 return -ENOMEM; 952 } 953 } else { 954 p->data = *to; 955 p->to_free = NULL; 956 } 957 p->mm = current->mm; 958 959 kiocb->private = p; 960 961 if (p->aio) 962 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 963 964 res = ffs_epfile_io(kiocb->ki_filp, p); 965 if (res == -EIOCBQUEUED) 966 return res; 967 968 if (p->aio) { 969 kfree(p->to_free); 970 kfree(p); 971 } else { 972 *to = p->data; 973 } 974 return res; 975 } 976 977 static int 978 ffs_epfile_release(struct inode *inode, struct file *file) 979 { 980 struct ffs_epfile *epfile = inode->i_private; 981 982 ENTER(); 983 984 ffs_data_closed(epfile->ffs); 985 986 return 0; 987 } 988 989 static long ffs_epfile_ioctl(struct file *file, unsigned code, 990 unsigned long value) 991 { 992 struct ffs_epfile *epfile = file->private_data; 993 int ret; 994 995 ENTER(); 996 997 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 998 return -ENODEV; 999 1000 spin_lock_irq(&epfile->ffs->eps_lock); 1001 if (likely(epfile->ep)) { 1002 switch (code) { 1003 case FUNCTIONFS_FIFO_STATUS: 1004 ret = usb_ep_fifo_status(epfile->ep->ep); 1005 break; 1006 case FUNCTIONFS_FIFO_FLUSH: 1007 usb_ep_fifo_flush(epfile->ep->ep); 1008 ret = 0; 1009 break; 1010 case FUNCTIONFS_CLEAR_HALT: 1011 ret = usb_ep_clear_halt(epfile->ep->ep); 1012 break; 1013 case FUNCTIONFS_ENDPOINT_REVMAP: 1014 ret = epfile->ep->num; 1015 break; 1016 case FUNCTIONFS_ENDPOINT_DESC: 1017 { 1018 int desc_idx; 1019 struct usb_endpoint_descriptor *desc; 1020 1021 switch (epfile->ffs->gadget->speed) { 1022 case USB_SPEED_SUPER: 1023 desc_idx = 2; 1024 break; 1025 case USB_SPEED_HIGH: 1026 desc_idx = 1; 1027 break; 1028 default: 1029 desc_idx = 0; 1030 } 1031 desc = epfile->ep->descs[desc_idx]; 1032 1033 spin_unlock_irq(&epfile->ffs->eps_lock); 1034 ret = copy_to_user((void *)value, desc, sizeof(*desc)); 1035 if (ret) 1036 ret = -EFAULT; 1037 return ret; 1038 } 1039 default: 1040 ret = -ENOTTY; 1041 } 1042 } else { 1043 ret = -ENODEV; 1044 } 1045 spin_unlock_irq(&epfile->ffs->eps_lock); 1046 1047 return ret; 1048 } 1049 1050 static const struct file_operations ffs_epfile_operations = { 1051 .llseek = no_llseek, 1052 1053 .open = ffs_epfile_open, 1054 .write_iter = ffs_epfile_write_iter, 1055 .read_iter = ffs_epfile_read_iter, 1056 .release = ffs_epfile_release, 1057 .unlocked_ioctl = ffs_epfile_ioctl, 1058 }; 1059 1060 1061 /* File system and super block operations ***********************************/ 1062 1063 /* 1064 * Mounting the file system creates a controller file, used first for 1065 * function configuration then later for event monitoring. 1066 */ 1067 1068 static struct inode *__must_check 1069 ffs_sb_make_inode(struct super_block *sb, void *data, 1070 const struct file_operations *fops, 1071 const struct inode_operations *iops, 1072 struct ffs_file_perms *perms) 1073 { 1074 struct inode *inode; 1075 1076 ENTER(); 1077 1078 inode = new_inode(sb); 1079 1080 if (likely(inode)) { 1081 struct timespec current_time = CURRENT_TIME; 1082 1083 inode->i_ino = get_next_ino(); 1084 inode->i_mode = perms->mode; 1085 inode->i_uid = perms->uid; 1086 inode->i_gid = perms->gid; 1087 inode->i_atime = current_time; 1088 inode->i_mtime = current_time; 1089 inode->i_ctime = current_time; 1090 inode->i_private = data; 1091 if (fops) 1092 inode->i_fop = fops; 1093 if (iops) 1094 inode->i_op = iops; 1095 } 1096 1097 return inode; 1098 } 1099 1100 /* Create "regular" file */ 1101 static struct dentry *ffs_sb_create_file(struct super_block *sb, 1102 const char *name, void *data, 1103 const struct file_operations *fops) 1104 { 1105 struct ffs_data *ffs = sb->s_fs_info; 1106 struct dentry *dentry; 1107 struct inode *inode; 1108 1109 ENTER(); 1110 1111 dentry = d_alloc_name(sb->s_root, name); 1112 if (unlikely(!dentry)) 1113 return NULL; 1114 1115 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms); 1116 if (unlikely(!inode)) { 1117 dput(dentry); 1118 return NULL; 1119 } 1120 1121 d_add(dentry, inode); 1122 return dentry; 1123 } 1124 1125 /* Super block */ 1126 static const struct super_operations ffs_sb_operations = { 1127 .statfs = simple_statfs, 1128 .drop_inode = generic_delete_inode, 1129 }; 1130 1131 struct ffs_sb_fill_data { 1132 struct ffs_file_perms perms; 1133 umode_t root_mode; 1134 const char *dev_name; 1135 bool no_disconnect; 1136 struct ffs_data *ffs_data; 1137 }; 1138 1139 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent) 1140 { 1141 struct ffs_sb_fill_data *data = _data; 1142 struct inode *inode; 1143 struct ffs_data *ffs = data->ffs_data; 1144 1145 ENTER(); 1146 1147 ffs->sb = sb; 1148 data->ffs_data = NULL; 1149 sb->s_fs_info = ffs; 1150 sb->s_blocksize = PAGE_SIZE; 1151 sb->s_blocksize_bits = PAGE_SHIFT; 1152 sb->s_magic = FUNCTIONFS_MAGIC; 1153 sb->s_op = &ffs_sb_operations; 1154 sb->s_time_gran = 1; 1155 1156 /* Root inode */ 1157 data->perms.mode = data->root_mode; 1158 inode = ffs_sb_make_inode(sb, NULL, 1159 &simple_dir_operations, 1160 &simple_dir_inode_operations, 1161 &data->perms); 1162 sb->s_root = d_make_root(inode); 1163 if (unlikely(!sb->s_root)) 1164 return -ENOMEM; 1165 1166 /* EP0 file */ 1167 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs, 1168 &ffs_ep0_operations))) 1169 return -ENOMEM; 1170 1171 return 0; 1172 } 1173 1174 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts) 1175 { 1176 ENTER(); 1177 1178 if (!opts || !*opts) 1179 return 0; 1180 1181 for (;;) { 1182 unsigned long value; 1183 char *eq, *comma; 1184 1185 /* Option limit */ 1186 comma = strchr(opts, ','); 1187 if (comma) 1188 *comma = 0; 1189 1190 /* Value limit */ 1191 eq = strchr(opts, '='); 1192 if (unlikely(!eq)) { 1193 pr_err("'=' missing in %s\n", opts); 1194 return -EINVAL; 1195 } 1196 *eq = 0; 1197 1198 /* Parse value */ 1199 if (kstrtoul(eq + 1, 0, &value)) { 1200 pr_err("%s: invalid value: %s\n", opts, eq + 1); 1201 return -EINVAL; 1202 } 1203 1204 /* Interpret option */ 1205 switch (eq - opts) { 1206 case 13: 1207 if (!memcmp(opts, "no_disconnect", 13)) 1208 data->no_disconnect = !!value; 1209 else 1210 goto invalid; 1211 break; 1212 case 5: 1213 if (!memcmp(opts, "rmode", 5)) 1214 data->root_mode = (value & 0555) | S_IFDIR; 1215 else if (!memcmp(opts, "fmode", 5)) 1216 data->perms.mode = (value & 0666) | S_IFREG; 1217 else 1218 goto invalid; 1219 break; 1220 1221 case 4: 1222 if (!memcmp(opts, "mode", 4)) { 1223 data->root_mode = (value & 0555) | S_IFDIR; 1224 data->perms.mode = (value & 0666) | S_IFREG; 1225 } else { 1226 goto invalid; 1227 } 1228 break; 1229 1230 case 3: 1231 if (!memcmp(opts, "uid", 3)) { 1232 data->perms.uid = make_kuid(current_user_ns(), value); 1233 if (!uid_valid(data->perms.uid)) { 1234 pr_err("%s: unmapped value: %lu\n", opts, value); 1235 return -EINVAL; 1236 } 1237 } else if (!memcmp(opts, "gid", 3)) { 1238 data->perms.gid = make_kgid(current_user_ns(), value); 1239 if (!gid_valid(data->perms.gid)) { 1240 pr_err("%s: unmapped value: %lu\n", opts, value); 1241 return -EINVAL; 1242 } 1243 } else { 1244 goto invalid; 1245 } 1246 break; 1247 1248 default: 1249 invalid: 1250 pr_err("%s: invalid option\n", opts); 1251 return -EINVAL; 1252 } 1253 1254 /* Next iteration */ 1255 if (!comma) 1256 break; 1257 opts = comma + 1; 1258 } 1259 1260 return 0; 1261 } 1262 1263 /* "mount -t functionfs dev_name /dev/function" ends up here */ 1264 1265 static struct dentry * 1266 ffs_fs_mount(struct file_system_type *t, int flags, 1267 const char *dev_name, void *opts) 1268 { 1269 struct ffs_sb_fill_data data = { 1270 .perms = { 1271 .mode = S_IFREG | 0600, 1272 .uid = GLOBAL_ROOT_UID, 1273 .gid = GLOBAL_ROOT_GID, 1274 }, 1275 .root_mode = S_IFDIR | 0500, 1276 .no_disconnect = false, 1277 }; 1278 struct dentry *rv; 1279 int ret; 1280 void *ffs_dev; 1281 struct ffs_data *ffs; 1282 1283 ENTER(); 1284 1285 ret = ffs_fs_parse_opts(&data, opts); 1286 if (unlikely(ret < 0)) 1287 return ERR_PTR(ret); 1288 1289 ffs = ffs_data_new(); 1290 if (unlikely(!ffs)) 1291 return ERR_PTR(-ENOMEM); 1292 ffs->file_perms = data.perms; 1293 ffs->no_disconnect = data.no_disconnect; 1294 1295 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL); 1296 if (unlikely(!ffs->dev_name)) { 1297 ffs_data_put(ffs); 1298 return ERR_PTR(-ENOMEM); 1299 } 1300 1301 ffs_dev = ffs_acquire_dev(dev_name); 1302 if (IS_ERR(ffs_dev)) { 1303 ffs_data_put(ffs); 1304 return ERR_CAST(ffs_dev); 1305 } 1306 ffs->private_data = ffs_dev; 1307 data.ffs_data = ffs; 1308 1309 rv = mount_nodev(t, flags, &data, ffs_sb_fill); 1310 if (IS_ERR(rv) && data.ffs_data) { 1311 ffs_release_dev(data.ffs_data); 1312 ffs_data_put(data.ffs_data); 1313 } 1314 return rv; 1315 } 1316 1317 static void 1318 ffs_fs_kill_sb(struct super_block *sb) 1319 { 1320 ENTER(); 1321 1322 kill_litter_super(sb); 1323 if (sb->s_fs_info) { 1324 ffs_release_dev(sb->s_fs_info); 1325 ffs_data_closed(sb->s_fs_info); 1326 ffs_data_put(sb->s_fs_info); 1327 } 1328 } 1329 1330 static struct file_system_type ffs_fs_type = { 1331 .owner = THIS_MODULE, 1332 .name = "functionfs", 1333 .mount = ffs_fs_mount, 1334 .kill_sb = ffs_fs_kill_sb, 1335 }; 1336 MODULE_ALIAS_FS("functionfs"); 1337 1338 1339 /* Driver's main init/cleanup functions *************************************/ 1340 1341 static int functionfs_init(void) 1342 { 1343 int ret; 1344 1345 ENTER(); 1346 1347 ret = register_filesystem(&ffs_fs_type); 1348 if (likely(!ret)) 1349 pr_info("file system registered\n"); 1350 else 1351 pr_err("failed registering file system (%d)\n", ret); 1352 1353 return ret; 1354 } 1355 1356 static void functionfs_cleanup(void) 1357 { 1358 ENTER(); 1359 1360 pr_info("unloading\n"); 1361 unregister_filesystem(&ffs_fs_type); 1362 } 1363 1364 1365 /* ffs_data and ffs_function construction and destruction code **************/ 1366 1367 static void ffs_data_clear(struct ffs_data *ffs); 1368 static void ffs_data_reset(struct ffs_data *ffs); 1369 1370 static void ffs_data_get(struct ffs_data *ffs) 1371 { 1372 ENTER(); 1373 1374 atomic_inc(&ffs->ref); 1375 } 1376 1377 static void ffs_data_opened(struct ffs_data *ffs) 1378 { 1379 ENTER(); 1380 1381 atomic_inc(&ffs->ref); 1382 if (atomic_add_return(1, &ffs->opened) == 1 && 1383 ffs->state == FFS_DEACTIVATED) { 1384 ffs->state = FFS_CLOSING; 1385 ffs_data_reset(ffs); 1386 } 1387 } 1388 1389 static void ffs_data_put(struct ffs_data *ffs) 1390 { 1391 ENTER(); 1392 1393 if (unlikely(atomic_dec_and_test(&ffs->ref))) { 1394 pr_info("%s(): freeing\n", __func__); 1395 ffs_data_clear(ffs); 1396 BUG_ON(waitqueue_active(&ffs->ev.waitq) || 1397 waitqueue_active(&ffs->ep0req_completion.wait)); 1398 kfree(ffs->dev_name); 1399 kfree(ffs); 1400 } 1401 } 1402 1403 static void ffs_data_closed(struct ffs_data *ffs) 1404 { 1405 ENTER(); 1406 1407 if (atomic_dec_and_test(&ffs->opened)) { 1408 if (ffs->no_disconnect) { 1409 ffs->state = FFS_DEACTIVATED; 1410 if (ffs->epfiles) { 1411 ffs_epfiles_destroy(ffs->epfiles, 1412 ffs->eps_count); 1413 ffs->epfiles = NULL; 1414 } 1415 if (ffs->setup_state == FFS_SETUP_PENDING) 1416 __ffs_ep0_stall(ffs); 1417 } else { 1418 ffs->state = FFS_CLOSING; 1419 ffs_data_reset(ffs); 1420 } 1421 } 1422 if (atomic_read(&ffs->opened) < 0) { 1423 ffs->state = FFS_CLOSING; 1424 ffs_data_reset(ffs); 1425 } 1426 1427 ffs_data_put(ffs); 1428 } 1429 1430 static struct ffs_data *ffs_data_new(void) 1431 { 1432 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL); 1433 if (unlikely(!ffs)) 1434 return NULL; 1435 1436 ENTER(); 1437 1438 atomic_set(&ffs->ref, 1); 1439 atomic_set(&ffs->opened, 0); 1440 ffs->state = FFS_READ_DESCRIPTORS; 1441 mutex_init(&ffs->mutex); 1442 spin_lock_init(&ffs->eps_lock); 1443 init_waitqueue_head(&ffs->ev.waitq); 1444 init_completion(&ffs->ep0req_completion); 1445 1446 /* XXX REVISIT need to update it in some places, or do we? */ 1447 ffs->ev.can_stall = 1; 1448 1449 return ffs; 1450 } 1451 1452 static void ffs_data_clear(struct ffs_data *ffs) 1453 { 1454 ENTER(); 1455 1456 ffs_closed(ffs); 1457 1458 BUG_ON(ffs->gadget); 1459 1460 if (ffs->epfiles) 1461 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count); 1462 1463 if (ffs->ffs_eventfd) 1464 eventfd_ctx_put(ffs->ffs_eventfd); 1465 1466 kfree(ffs->raw_descs_data); 1467 kfree(ffs->raw_strings); 1468 kfree(ffs->stringtabs); 1469 } 1470 1471 static void ffs_data_reset(struct ffs_data *ffs) 1472 { 1473 ENTER(); 1474 1475 ffs_data_clear(ffs); 1476 1477 ffs->epfiles = NULL; 1478 ffs->raw_descs_data = NULL; 1479 ffs->raw_descs = NULL; 1480 ffs->raw_strings = NULL; 1481 ffs->stringtabs = NULL; 1482 1483 ffs->raw_descs_length = 0; 1484 ffs->fs_descs_count = 0; 1485 ffs->hs_descs_count = 0; 1486 ffs->ss_descs_count = 0; 1487 1488 ffs->strings_count = 0; 1489 ffs->interfaces_count = 0; 1490 ffs->eps_count = 0; 1491 1492 ffs->ev.count = 0; 1493 1494 ffs->state = FFS_READ_DESCRIPTORS; 1495 ffs->setup_state = FFS_NO_SETUP; 1496 ffs->flags = 0; 1497 } 1498 1499 1500 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) 1501 { 1502 struct usb_gadget_strings **lang; 1503 int first_id; 1504 1505 ENTER(); 1506 1507 if (WARN_ON(ffs->state != FFS_ACTIVE 1508 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags))) 1509 return -EBADFD; 1510 1511 first_id = usb_string_ids_n(cdev, ffs->strings_count); 1512 if (unlikely(first_id < 0)) 1513 return first_id; 1514 1515 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); 1516 if (unlikely(!ffs->ep0req)) 1517 return -ENOMEM; 1518 ffs->ep0req->complete = ffs_ep0_complete; 1519 ffs->ep0req->context = ffs; 1520 1521 lang = ffs->stringtabs; 1522 if (lang) { 1523 for (; *lang; ++lang) { 1524 struct usb_string *str = (*lang)->strings; 1525 int id = first_id; 1526 for (; str->s; ++id, ++str) 1527 str->id = id; 1528 } 1529 } 1530 1531 ffs->gadget = cdev->gadget; 1532 ffs_data_get(ffs); 1533 return 0; 1534 } 1535 1536 static void functionfs_unbind(struct ffs_data *ffs) 1537 { 1538 ENTER(); 1539 1540 if (!WARN_ON(!ffs->gadget)) { 1541 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req); 1542 ffs->ep0req = NULL; 1543 ffs->gadget = NULL; 1544 clear_bit(FFS_FL_BOUND, &ffs->flags); 1545 ffs_data_put(ffs); 1546 } 1547 } 1548 1549 static int ffs_epfiles_create(struct ffs_data *ffs) 1550 { 1551 struct ffs_epfile *epfile, *epfiles; 1552 unsigned i, count; 1553 1554 ENTER(); 1555 1556 count = ffs->eps_count; 1557 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL); 1558 if (!epfiles) 1559 return -ENOMEM; 1560 1561 epfile = epfiles; 1562 for (i = 1; i <= count; ++i, ++epfile) { 1563 epfile->ffs = ffs; 1564 mutex_init(&epfile->mutex); 1565 init_waitqueue_head(&epfile->wait); 1566 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 1567 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]); 1568 else 1569 sprintf(epfile->name, "ep%u", i); 1570 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name, 1571 epfile, 1572 &ffs_epfile_operations); 1573 if (unlikely(!epfile->dentry)) { 1574 ffs_epfiles_destroy(epfiles, i - 1); 1575 return -ENOMEM; 1576 } 1577 } 1578 1579 ffs->epfiles = epfiles; 1580 return 0; 1581 } 1582 1583 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count) 1584 { 1585 struct ffs_epfile *epfile = epfiles; 1586 1587 ENTER(); 1588 1589 for (; count; --count, ++epfile) { 1590 BUG_ON(mutex_is_locked(&epfile->mutex) || 1591 waitqueue_active(&epfile->wait)); 1592 if (epfile->dentry) { 1593 d_delete(epfile->dentry); 1594 dput(epfile->dentry); 1595 epfile->dentry = NULL; 1596 } 1597 } 1598 1599 kfree(epfiles); 1600 } 1601 1602 static void ffs_func_eps_disable(struct ffs_function *func) 1603 { 1604 struct ffs_ep *ep = func->eps; 1605 struct ffs_epfile *epfile = func->ffs->epfiles; 1606 unsigned count = func->ffs->eps_count; 1607 unsigned long flags; 1608 1609 spin_lock_irqsave(&func->ffs->eps_lock, flags); 1610 do { 1611 /* pending requests get nuked */ 1612 if (likely(ep->ep)) 1613 usb_ep_disable(ep->ep); 1614 ++ep; 1615 1616 if (epfile) { 1617 epfile->ep = NULL; 1618 ++epfile; 1619 } 1620 } while (--count); 1621 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 1622 } 1623 1624 static int ffs_func_eps_enable(struct ffs_function *func) 1625 { 1626 struct ffs_data *ffs = func->ffs; 1627 struct ffs_ep *ep = func->eps; 1628 struct ffs_epfile *epfile = ffs->epfiles; 1629 unsigned count = ffs->eps_count; 1630 unsigned long flags; 1631 int ret = 0; 1632 1633 spin_lock_irqsave(&func->ffs->eps_lock, flags); 1634 do { 1635 struct usb_endpoint_descriptor *ds; 1636 int desc_idx; 1637 1638 if (ffs->gadget->speed == USB_SPEED_SUPER) 1639 desc_idx = 2; 1640 else if (ffs->gadget->speed == USB_SPEED_HIGH) 1641 desc_idx = 1; 1642 else 1643 desc_idx = 0; 1644 1645 /* fall-back to lower speed if desc missing for current speed */ 1646 do { 1647 ds = ep->descs[desc_idx]; 1648 } while (!ds && --desc_idx >= 0); 1649 1650 if (!ds) { 1651 ret = -EINVAL; 1652 break; 1653 } 1654 1655 ep->ep->driver_data = ep; 1656 ep->ep->desc = ds; 1657 ret = usb_ep_enable(ep->ep); 1658 if (likely(!ret)) { 1659 epfile->ep = ep; 1660 epfile->in = usb_endpoint_dir_in(ds); 1661 epfile->isoc = usb_endpoint_xfer_isoc(ds); 1662 } else { 1663 break; 1664 } 1665 1666 wake_up(&epfile->wait); 1667 1668 ++ep; 1669 ++epfile; 1670 } while (--count); 1671 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 1672 1673 return ret; 1674 } 1675 1676 1677 /* Parsing and building descriptors and strings *****************************/ 1678 1679 /* 1680 * This validates if data pointed by data is a valid USB descriptor as 1681 * well as record how many interfaces, endpoints and strings are 1682 * required by given configuration. Returns address after the 1683 * descriptor or NULL if data is invalid. 1684 */ 1685 1686 enum ffs_entity_type { 1687 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT 1688 }; 1689 1690 enum ffs_os_desc_type { 1691 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP 1692 }; 1693 1694 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity, 1695 u8 *valuep, 1696 struct usb_descriptor_header *desc, 1697 void *priv); 1698 1699 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity, 1700 struct usb_os_desc_header *h, void *data, 1701 unsigned len, void *priv); 1702 1703 static int __must_check ffs_do_single_desc(char *data, unsigned len, 1704 ffs_entity_callback entity, 1705 void *priv) 1706 { 1707 struct usb_descriptor_header *_ds = (void *)data; 1708 u8 length; 1709 int ret; 1710 1711 ENTER(); 1712 1713 /* At least two bytes are required: length and type */ 1714 if (len < 2) { 1715 pr_vdebug("descriptor too short\n"); 1716 return -EINVAL; 1717 } 1718 1719 /* If we have at least as many bytes as the descriptor takes? */ 1720 length = _ds->bLength; 1721 if (len < length) { 1722 pr_vdebug("descriptor longer then available data\n"); 1723 return -EINVAL; 1724 } 1725 1726 #define __entity_check_INTERFACE(val) 1 1727 #define __entity_check_STRING(val) (val) 1728 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK) 1729 #define __entity(type, val) do { \ 1730 pr_vdebug("entity " #type "(%02x)\n", (val)); \ 1731 if (unlikely(!__entity_check_ ##type(val))) { \ 1732 pr_vdebug("invalid entity's value\n"); \ 1733 return -EINVAL; \ 1734 } \ 1735 ret = entity(FFS_ ##type, &val, _ds, priv); \ 1736 if (unlikely(ret < 0)) { \ 1737 pr_debug("entity " #type "(%02x); ret = %d\n", \ 1738 (val), ret); \ 1739 return ret; \ 1740 } \ 1741 } while (0) 1742 1743 /* Parse descriptor depending on type. */ 1744 switch (_ds->bDescriptorType) { 1745 case USB_DT_DEVICE: 1746 case USB_DT_CONFIG: 1747 case USB_DT_STRING: 1748 case USB_DT_DEVICE_QUALIFIER: 1749 /* function can't have any of those */ 1750 pr_vdebug("descriptor reserved for gadget: %d\n", 1751 _ds->bDescriptorType); 1752 return -EINVAL; 1753 1754 case USB_DT_INTERFACE: { 1755 struct usb_interface_descriptor *ds = (void *)_ds; 1756 pr_vdebug("interface descriptor\n"); 1757 if (length != sizeof *ds) 1758 goto inv_length; 1759 1760 __entity(INTERFACE, ds->bInterfaceNumber); 1761 if (ds->iInterface) 1762 __entity(STRING, ds->iInterface); 1763 } 1764 break; 1765 1766 case USB_DT_ENDPOINT: { 1767 struct usb_endpoint_descriptor *ds = (void *)_ds; 1768 pr_vdebug("endpoint descriptor\n"); 1769 if (length != USB_DT_ENDPOINT_SIZE && 1770 length != USB_DT_ENDPOINT_AUDIO_SIZE) 1771 goto inv_length; 1772 __entity(ENDPOINT, ds->bEndpointAddress); 1773 } 1774 break; 1775 1776 case HID_DT_HID: 1777 pr_vdebug("hid descriptor\n"); 1778 if (length != sizeof(struct hid_descriptor)) 1779 goto inv_length; 1780 break; 1781 1782 case USB_DT_OTG: 1783 if (length != sizeof(struct usb_otg_descriptor)) 1784 goto inv_length; 1785 break; 1786 1787 case USB_DT_INTERFACE_ASSOCIATION: { 1788 struct usb_interface_assoc_descriptor *ds = (void *)_ds; 1789 pr_vdebug("interface association descriptor\n"); 1790 if (length != sizeof *ds) 1791 goto inv_length; 1792 if (ds->iFunction) 1793 __entity(STRING, ds->iFunction); 1794 } 1795 break; 1796 1797 case USB_DT_SS_ENDPOINT_COMP: 1798 pr_vdebug("EP SS companion descriptor\n"); 1799 if (length != sizeof(struct usb_ss_ep_comp_descriptor)) 1800 goto inv_length; 1801 break; 1802 1803 case USB_DT_OTHER_SPEED_CONFIG: 1804 case USB_DT_INTERFACE_POWER: 1805 case USB_DT_DEBUG: 1806 case USB_DT_SECURITY: 1807 case USB_DT_CS_RADIO_CONTROL: 1808 /* TODO */ 1809 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType); 1810 return -EINVAL; 1811 1812 default: 1813 /* We should never be here */ 1814 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType); 1815 return -EINVAL; 1816 1817 inv_length: 1818 pr_vdebug("invalid length: %d (descriptor %d)\n", 1819 _ds->bLength, _ds->bDescriptorType); 1820 return -EINVAL; 1821 } 1822 1823 #undef __entity 1824 #undef __entity_check_DESCRIPTOR 1825 #undef __entity_check_INTERFACE 1826 #undef __entity_check_STRING 1827 #undef __entity_check_ENDPOINT 1828 1829 return length; 1830 } 1831 1832 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, 1833 ffs_entity_callback entity, void *priv) 1834 { 1835 const unsigned _len = len; 1836 unsigned long num = 0; 1837 1838 ENTER(); 1839 1840 for (;;) { 1841 int ret; 1842 1843 if (num == count) 1844 data = NULL; 1845 1846 /* Record "descriptor" entity */ 1847 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv); 1848 if (unlikely(ret < 0)) { 1849 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n", 1850 num, ret); 1851 return ret; 1852 } 1853 1854 if (!data) 1855 return _len - len; 1856 1857 ret = ffs_do_single_desc(data, len, entity, priv); 1858 if (unlikely(ret < 0)) { 1859 pr_debug("%s returns %d\n", __func__, ret); 1860 return ret; 1861 } 1862 1863 len -= ret; 1864 data += ret; 1865 ++num; 1866 } 1867 } 1868 1869 static int __ffs_data_do_entity(enum ffs_entity_type type, 1870 u8 *valuep, struct usb_descriptor_header *desc, 1871 void *priv) 1872 { 1873 struct ffs_desc_helper *helper = priv; 1874 struct usb_endpoint_descriptor *d; 1875 1876 ENTER(); 1877 1878 switch (type) { 1879 case FFS_DESCRIPTOR: 1880 break; 1881 1882 case FFS_INTERFACE: 1883 /* 1884 * Interfaces are indexed from zero so if we 1885 * encountered interface "n" then there are at least 1886 * "n+1" interfaces. 1887 */ 1888 if (*valuep >= helper->interfaces_count) 1889 helper->interfaces_count = *valuep + 1; 1890 break; 1891 1892 case FFS_STRING: 1893 /* 1894 * Strings are indexed from 1 (0 is magic ;) reserved 1895 * for languages list or some such) 1896 */ 1897 if (*valuep > helper->ffs->strings_count) 1898 helper->ffs->strings_count = *valuep; 1899 break; 1900 1901 case FFS_ENDPOINT: 1902 d = (void *)desc; 1903 helper->eps_count++; 1904 if (helper->eps_count >= 15) 1905 return -EINVAL; 1906 /* Check if descriptors for any speed were already parsed */ 1907 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count) 1908 helper->ffs->eps_addrmap[helper->eps_count] = 1909 d->bEndpointAddress; 1910 else if (helper->ffs->eps_addrmap[helper->eps_count] != 1911 d->bEndpointAddress) 1912 return -EINVAL; 1913 break; 1914 } 1915 1916 return 0; 1917 } 1918 1919 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type, 1920 struct usb_os_desc_header *desc) 1921 { 1922 u16 bcd_version = le16_to_cpu(desc->bcdVersion); 1923 u16 w_index = le16_to_cpu(desc->wIndex); 1924 1925 if (bcd_version != 1) { 1926 pr_vdebug("unsupported os descriptors version: %d", 1927 bcd_version); 1928 return -EINVAL; 1929 } 1930 switch (w_index) { 1931 case 0x4: 1932 *next_type = FFS_OS_DESC_EXT_COMPAT; 1933 break; 1934 case 0x5: 1935 *next_type = FFS_OS_DESC_EXT_PROP; 1936 break; 1937 default: 1938 pr_vdebug("unsupported os descriptor type: %d", w_index); 1939 return -EINVAL; 1940 } 1941 1942 return sizeof(*desc); 1943 } 1944 1945 /* 1946 * Process all extended compatibility/extended property descriptors 1947 * of a feature descriptor 1948 */ 1949 static int __must_check ffs_do_single_os_desc(char *data, unsigned len, 1950 enum ffs_os_desc_type type, 1951 u16 feature_count, 1952 ffs_os_desc_callback entity, 1953 void *priv, 1954 struct usb_os_desc_header *h) 1955 { 1956 int ret; 1957 const unsigned _len = len; 1958 1959 ENTER(); 1960 1961 /* loop over all ext compat/ext prop descriptors */ 1962 while (feature_count--) { 1963 ret = entity(type, h, data, len, priv); 1964 if (unlikely(ret < 0)) { 1965 pr_debug("bad OS descriptor, type: %d\n", type); 1966 return ret; 1967 } 1968 data += ret; 1969 len -= ret; 1970 } 1971 return _len - len; 1972 } 1973 1974 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */ 1975 static int __must_check ffs_do_os_descs(unsigned count, 1976 char *data, unsigned len, 1977 ffs_os_desc_callback entity, void *priv) 1978 { 1979 const unsigned _len = len; 1980 unsigned long num = 0; 1981 1982 ENTER(); 1983 1984 for (num = 0; num < count; ++num) { 1985 int ret; 1986 enum ffs_os_desc_type type; 1987 u16 feature_count; 1988 struct usb_os_desc_header *desc = (void *)data; 1989 1990 if (len < sizeof(*desc)) 1991 return -EINVAL; 1992 1993 /* 1994 * Record "descriptor" entity. 1995 * Process dwLength, bcdVersion, wIndex, get b/wCount. 1996 * Move the data pointer to the beginning of extended 1997 * compatibilities proper or extended properties proper 1998 * portions of the data 1999 */ 2000 if (le32_to_cpu(desc->dwLength) > len) 2001 return -EINVAL; 2002 2003 ret = __ffs_do_os_desc_header(&type, desc); 2004 if (unlikely(ret < 0)) { 2005 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n", 2006 num, ret); 2007 return ret; 2008 } 2009 /* 2010 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??" 2011 */ 2012 feature_count = le16_to_cpu(desc->wCount); 2013 if (type == FFS_OS_DESC_EXT_COMPAT && 2014 (feature_count > 255 || desc->Reserved)) 2015 return -EINVAL; 2016 len -= ret; 2017 data += ret; 2018 2019 /* 2020 * Process all function/property descriptors 2021 * of this Feature Descriptor 2022 */ 2023 ret = ffs_do_single_os_desc(data, len, type, 2024 feature_count, entity, priv, desc); 2025 if (unlikely(ret < 0)) { 2026 pr_debug("%s returns %d\n", __func__, ret); 2027 return ret; 2028 } 2029 2030 len -= ret; 2031 data += ret; 2032 } 2033 return _len - len; 2034 } 2035 2036 /** 2037 * Validate contents of the buffer from userspace related to OS descriptors. 2038 */ 2039 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type, 2040 struct usb_os_desc_header *h, void *data, 2041 unsigned len, void *priv) 2042 { 2043 struct ffs_data *ffs = priv; 2044 u8 length; 2045 2046 ENTER(); 2047 2048 switch (type) { 2049 case FFS_OS_DESC_EXT_COMPAT: { 2050 struct usb_ext_compat_desc *d = data; 2051 int i; 2052 2053 if (len < sizeof(*d) || 2054 d->bFirstInterfaceNumber >= ffs->interfaces_count || 2055 d->Reserved1) 2056 return -EINVAL; 2057 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i) 2058 if (d->Reserved2[i]) 2059 return -EINVAL; 2060 2061 length = sizeof(struct usb_ext_compat_desc); 2062 } 2063 break; 2064 case FFS_OS_DESC_EXT_PROP: { 2065 struct usb_ext_prop_desc *d = data; 2066 u32 type, pdl; 2067 u16 pnl; 2068 2069 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count) 2070 return -EINVAL; 2071 length = le32_to_cpu(d->dwSize); 2072 type = le32_to_cpu(d->dwPropertyDataType); 2073 if (type < USB_EXT_PROP_UNICODE || 2074 type > USB_EXT_PROP_UNICODE_MULTI) { 2075 pr_vdebug("unsupported os descriptor property type: %d", 2076 type); 2077 return -EINVAL; 2078 } 2079 pnl = le16_to_cpu(d->wPropertyNameLength); 2080 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl)); 2081 if (length != 14 + pnl + pdl) { 2082 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n", 2083 length, pnl, pdl, type); 2084 return -EINVAL; 2085 } 2086 ++ffs->ms_os_descs_ext_prop_count; 2087 /* property name reported to the host as "WCHAR"s */ 2088 ffs->ms_os_descs_ext_prop_name_len += pnl * 2; 2089 ffs->ms_os_descs_ext_prop_data_len += pdl; 2090 } 2091 break; 2092 default: 2093 pr_vdebug("unknown descriptor: %d\n", type); 2094 return -EINVAL; 2095 } 2096 return length; 2097 } 2098 2099 static int __ffs_data_got_descs(struct ffs_data *ffs, 2100 char *const _data, size_t len) 2101 { 2102 char *data = _data, *raw_descs; 2103 unsigned os_descs_count = 0, counts[3], flags; 2104 int ret = -EINVAL, i; 2105 struct ffs_desc_helper helper; 2106 2107 ENTER(); 2108 2109 if (get_unaligned_le32(data + 4) != len) 2110 goto error; 2111 2112 switch (get_unaligned_le32(data)) { 2113 case FUNCTIONFS_DESCRIPTORS_MAGIC: 2114 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC; 2115 data += 8; 2116 len -= 8; 2117 break; 2118 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2: 2119 flags = get_unaligned_le32(data + 8); 2120 ffs->user_flags = flags; 2121 if (flags & ~(FUNCTIONFS_HAS_FS_DESC | 2122 FUNCTIONFS_HAS_HS_DESC | 2123 FUNCTIONFS_HAS_SS_DESC | 2124 FUNCTIONFS_HAS_MS_OS_DESC | 2125 FUNCTIONFS_VIRTUAL_ADDR | 2126 FUNCTIONFS_EVENTFD)) { 2127 ret = -ENOSYS; 2128 goto error; 2129 } 2130 data += 12; 2131 len -= 12; 2132 break; 2133 default: 2134 goto error; 2135 } 2136 2137 if (flags & FUNCTIONFS_EVENTFD) { 2138 if (len < 4) 2139 goto error; 2140 ffs->ffs_eventfd = 2141 eventfd_ctx_fdget((int)get_unaligned_le32(data)); 2142 if (IS_ERR(ffs->ffs_eventfd)) { 2143 ret = PTR_ERR(ffs->ffs_eventfd); 2144 ffs->ffs_eventfd = NULL; 2145 goto error; 2146 } 2147 data += 4; 2148 len -= 4; 2149 } 2150 2151 /* Read fs_count, hs_count and ss_count (if present) */ 2152 for (i = 0; i < 3; ++i) { 2153 if (!(flags & (1 << i))) { 2154 counts[i] = 0; 2155 } else if (len < 4) { 2156 goto error; 2157 } else { 2158 counts[i] = get_unaligned_le32(data); 2159 data += 4; 2160 len -= 4; 2161 } 2162 } 2163 if (flags & (1 << i)) { 2164 os_descs_count = get_unaligned_le32(data); 2165 data += 4; 2166 len -= 4; 2167 }; 2168 2169 /* Read descriptors */ 2170 raw_descs = data; 2171 helper.ffs = ffs; 2172 for (i = 0; i < 3; ++i) { 2173 if (!counts[i]) 2174 continue; 2175 helper.interfaces_count = 0; 2176 helper.eps_count = 0; 2177 ret = ffs_do_descs(counts[i], data, len, 2178 __ffs_data_do_entity, &helper); 2179 if (ret < 0) 2180 goto error; 2181 if (!ffs->eps_count && !ffs->interfaces_count) { 2182 ffs->eps_count = helper.eps_count; 2183 ffs->interfaces_count = helper.interfaces_count; 2184 } else { 2185 if (ffs->eps_count != helper.eps_count) { 2186 ret = -EINVAL; 2187 goto error; 2188 } 2189 if (ffs->interfaces_count != helper.interfaces_count) { 2190 ret = -EINVAL; 2191 goto error; 2192 } 2193 } 2194 data += ret; 2195 len -= ret; 2196 } 2197 if (os_descs_count) { 2198 ret = ffs_do_os_descs(os_descs_count, data, len, 2199 __ffs_data_do_os_desc, ffs); 2200 if (ret < 0) 2201 goto error; 2202 data += ret; 2203 len -= ret; 2204 } 2205 2206 if (raw_descs == data || len) { 2207 ret = -EINVAL; 2208 goto error; 2209 } 2210 2211 ffs->raw_descs_data = _data; 2212 ffs->raw_descs = raw_descs; 2213 ffs->raw_descs_length = data - raw_descs; 2214 ffs->fs_descs_count = counts[0]; 2215 ffs->hs_descs_count = counts[1]; 2216 ffs->ss_descs_count = counts[2]; 2217 ffs->ms_os_descs_count = os_descs_count; 2218 2219 return 0; 2220 2221 error: 2222 kfree(_data); 2223 return ret; 2224 } 2225 2226 static int __ffs_data_got_strings(struct ffs_data *ffs, 2227 char *const _data, size_t len) 2228 { 2229 u32 str_count, needed_count, lang_count; 2230 struct usb_gadget_strings **stringtabs, *t; 2231 struct usb_string *strings, *s; 2232 const char *data = _data; 2233 2234 ENTER(); 2235 2236 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC || 2237 get_unaligned_le32(data + 4) != len)) 2238 goto error; 2239 str_count = get_unaligned_le32(data + 8); 2240 lang_count = get_unaligned_le32(data + 12); 2241 2242 /* if one is zero the other must be zero */ 2243 if (unlikely(!str_count != !lang_count)) 2244 goto error; 2245 2246 /* Do we have at least as many strings as descriptors need? */ 2247 needed_count = ffs->strings_count; 2248 if (unlikely(str_count < needed_count)) 2249 goto error; 2250 2251 /* 2252 * If we don't need any strings just return and free all 2253 * memory. 2254 */ 2255 if (!needed_count) { 2256 kfree(_data); 2257 return 0; 2258 } 2259 2260 /* Allocate everything in one chunk so there's less maintenance. */ 2261 { 2262 unsigned i = 0; 2263 vla_group(d); 2264 vla_item(d, struct usb_gadget_strings *, stringtabs, 2265 lang_count + 1); 2266 vla_item(d, struct usb_gadget_strings, stringtab, lang_count); 2267 vla_item(d, struct usb_string, strings, 2268 lang_count*(needed_count+1)); 2269 2270 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL); 2271 2272 if (unlikely(!vlabuf)) { 2273 kfree(_data); 2274 return -ENOMEM; 2275 } 2276 2277 /* Initialize the VLA pointers */ 2278 stringtabs = vla_ptr(vlabuf, d, stringtabs); 2279 t = vla_ptr(vlabuf, d, stringtab); 2280 i = lang_count; 2281 do { 2282 *stringtabs++ = t++; 2283 } while (--i); 2284 *stringtabs = NULL; 2285 2286 /* stringtabs = vlabuf = d_stringtabs for later kfree */ 2287 stringtabs = vla_ptr(vlabuf, d, stringtabs); 2288 t = vla_ptr(vlabuf, d, stringtab); 2289 s = vla_ptr(vlabuf, d, strings); 2290 strings = s; 2291 } 2292 2293 /* For each language */ 2294 data += 16; 2295 len -= 16; 2296 2297 do { /* lang_count > 0 so we can use do-while */ 2298 unsigned needed = needed_count; 2299 2300 if (unlikely(len < 3)) 2301 goto error_free; 2302 t->language = get_unaligned_le16(data); 2303 t->strings = s; 2304 ++t; 2305 2306 data += 2; 2307 len -= 2; 2308 2309 /* For each string */ 2310 do { /* str_count > 0 so we can use do-while */ 2311 size_t length = strnlen(data, len); 2312 2313 if (unlikely(length == len)) 2314 goto error_free; 2315 2316 /* 2317 * User may provide more strings then we need, 2318 * if that's the case we simply ignore the 2319 * rest 2320 */ 2321 if (likely(needed)) { 2322 /* 2323 * s->id will be set while adding 2324 * function to configuration so for 2325 * now just leave garbage here. 2326 */ 2327 s->s = data; 2328 --needed; 2329 ++s; 2330 } 2331 2332 data += length + 1; 2333 len -= length + 1; 2334 } while (--str_count); 2335 2336 s->id = 0; /* terminator */ 2337 s->s = NULL; 2338 ++s; 2339 2340 } while (--lang_count); 2341 2342 /* Some garbage left? */ 2343 if (unlikely(len)) 2344 goto error_free; 2345 2346 /* Done! */ 2347 ffs->stringtabs = stringtabs; 2348 ffs->raw_strings = _data; 2349 2350 return 0; 2351 2352 error_free: 2353 kfree(stringtabs); 2354 error: 2355 kfree(_data); 2356 return -EINVAL; 2357 } 2358 2359 2360 /* Events handling and management *******************************************/ 2361 2362 static void __ffs_event_add(struct ffs_data *ffs, 2363 enum usb_functionfs_event_type type) 2364 { 2365 enum usb_functionfs_event_type rem_type1, rem_type2 = type; 2366 int neg = 0; 2367 2368 /* 2369 * Abort any unhandled setup 2370 * 2371 * We do not need to worry about some cmpxchg() changing value 2372 * of ffs->setup_state without holding the lock because when 2373 * state is FFS_SETUP_PENDING cmpxchg() in several places in 2374 * the source does nothing. 2375 */ 2376 if (ffs->setup_state == FFS_SETUP_PENDING) 2377 ffs->setup_state = FFS_SETUP_CANCELLED; 2378 2379 /* 2380 * Logic of this function guarantees that there are at most four pending 2381 * evens on ffs->ev.types queue. This is important because the queue 2382 * has space for four elements only and __ffs_ep0_read_events function 2383 * depends on that limit as well. If more event types are added, those 2384 * limits have to be revisited or guaranteed to still hold. 2385 */ 2386 switch (type) { 2387 case FUNCTIONFS_RESUME: 2388 rem_type2 = FUNCTIONFS_SUSPEND; 2389 /* FALL THROUGH */ 2390 case FUNCTIONFS_SUSPEND: 2391 case FUNCTIONFS_SETUP: 2392 rem_type1 = type; 2393 /* Discard all similar events */ 2394 break; 2395 2396 case FUNCTIONFS_BIND: 2397 case FUNCTIONFS_UNBIND: 2398 case FUNCTIONFS_DISABLE: 2399 case FUNCTIONFS_ENABLE: 2400 /* Discard everything other then power management. */ 2401 rem_type1 = FUNCTIONFS_SUSPEND; 2402 rem_type2 = FUNCTIONFS_RESUME; 2403 neg = 1; 2404 break; 2405 2406 default: 2407 WARN(1, "%d: unknown event, this should not happen\n", type); 2408 return; 2409 } 2410 2411 { 2412 u8 *ev = ffs->ev.types, *out = ev; 2413 unsigned n = ffs->ev.count; 2414 for (; n; --n, ++ev) 2415 if ((*ev == rem_type1 || *ev == rem_type2) == neg) 2416 *out++ = *ev; 2417 else 2418 pr_vdebug("purging event %d\n", *ev); 2419 ffs->ev.count = out - ffs->ev.types; 2420 } 2421 2422 pr_vdebug("adding event %d\n", type); 2423 ffs->ev.types[ffs->ev.count++] = type; 2424 wake_up_locked(&ffs->ev.waitq); 2425 if (ffs->ffs_eventfd) 2426 eventfd_signal(ffs->ffs_eventfd, 1); 2427 } 2428 2429 static void ffs_event_add(struct ffs_data *ffs, 2430 enum usb_functionfs_event_type type) 2431 { 2432 unsigned long flags; 2433 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 2434 __ffs_event_add(ffs, type); 2435 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 2436 } 2437 2438 /* Bind/unbind USB function hooks *******************************************/ 2439 2440 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address) 2441 { 2442 int i; 2443 2444 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i) 2445 if (ffs->eps_addrmap[i] == endpoint_address) 2446 return i; 2447 return -ENOENT; 2448 } 2449 2450 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep, 2451 struct usb_descriptor_header *desc, 2452 void *priv) 2453 { 2454 struct usb_endpoint_descriptor *ds = (void *)desc; 2455 struct ffs_function *func = priv; 2456 struct ffs_ep *ffs_ep; 2457 unsigned ep_desc_id; 2458 int idx; 2459 static const char *speed_names[] = { "full", "high", "super" }; 2460 2461 if (type != FFS_DESCRIPTOR) 2462 return 0; 2463 2464 /* 2465 * If ss_descriptors is not NULL, we are reading super speed 2466 * descriptors; if hs_descriptors is not NULL, we are reading high 2467 * speed descriptors; otherwise, we are reading full speed 2468 * descriptors. 2469 */ 2470 if (func->function.ss_descriptors) { 2471 ep_desc_id = 2; 2472 func->function.ss_descriptors[(long)valuep] = desc; 2473 } else if (func->function.hs_descriptors) { 2474 ep_desc_id = 1; 2475 func->function.hs_descriptors[(long)valuep] = desc; 2476 } else { 2477 ep_desc_id = 0; 2478 func->function.fs_descriptors[(long)valuep] = desc; 2479 } 2480 2481 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) 2482 return 0; 2483 2484 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1; 2485 if (idx < 0) 2486 return idx; 2487 2488 ffs_ep = func->eps + idx; 2489 2490 if (unlikely(ffs_ep->descs[ep_desc_id])) { 2491 pr_err("two %sspeed descriptors for EP %d\n", 2492 speed_names[ep_desc_id], 2493 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); 2494 return -EINVAL; 2495 } 2496 ffs_ep->descs[ep_desc_id] = ds; 2497 2498 ffs_dump_mem(": Original ep desc", ds, ds->bLength); 2499 if (ffs_ep->ep) { 2500 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress; 2501 if (!ds->wMaxPacketSize) 2502 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize; 2503 } else { 2504 struct usb_request *req; 2505 struct usb_ep *ep; 2506 u8 bEndpointAddress; 2507 2508 /* 2509 * We back up bEndpointAddress because autoconfig overwrites 2510 * it with physical endpoint address. 2511 */ 2512 bEndpointAddress = ds->bEndpointAddress; 2513 pr_vdebug("autoconfig\n"); 2514 ep = usb_ep_autoconfig(func->gadget, ds); 2515 if (unlikely(!ep)) 2516 return -ENOTSUPP; 2517 ep->driver_data = func->eps + idx; 2518 2519 req = usb_ep_alloc_request(ep, GFP_KERNEL); 2520 if (unlikely(!req)) 2521 return -ENOMEM; 2522 2523 ffs_ep->ep = ep; 2524 ffs_ep->req = req; 2525 func->eps_revmap[ds->bEndpointAddress & 2526 USB_ENDPOINT_NUMBER_MASK] = idx + 1; 2527 /* 2528 * If we use virtual address mapping, we restore 2529 * original bEndpointAddress value. 2530 */ 2531 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 2532 ds->bEndpointAddress = bEndpointAddress; 2533 } 2534 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength); 2535 2536 return 0; 2537 } 2538 2539 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep, 2540 struct usb_descriptor_header *desc, 2541 void *priv) 2542 { 2543 struct ffs_function *func = priv; 2544 unsigned idx; 2545 u8 newValue; 2546 2547 switch (type) { 2548 default: 2549 case FFS_DESCRIPTOR: 2550 /* Handled in previous pass by __ffs_func_bind_do_descs() */ 2551 return 0; 2552 2553 case FFS_INTERFACE: 2554 idx = *valuep; 2555 if (func->interfaces_nums[idx] < 0) { 2556 int id = usb_interface_id(func->conf, &func->function); 2557 if (unlikely(id < 0)) 2558 return id; 2559 func->interfaces_nums[idx] = id; 2560 } 2561 newValue = func->interfaces_nums[idx]; 2562 break; 2563 2564 case FFS_STRING: 2565 /* String' IDs are allocated when fsf_data is bound to cdev */ 2566 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id; 2567 break; 2568 2569 case FFS_ENDPOINT: 2570 /* 2571 * USB_DT_ENDPOINT are handled in 2572 * __ffs_func_bind_do_descs(). 2573 */ 2574 if (desc->bDescriptorType == USB_DT_ENDPOINT) 2575 return 0; 2576 2577 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1; 2578 if (unlikely(!func->eps[idx].ep)) 2579 return -EINVAL; 2580 2581 { 2582 struct usb_endpoint_descriptor **descs; 2583 descs = func->eps[idx].descs; 2584 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress; 2585 } 2586 break; 2587 } 2588 2589 pr_vdebug("%02x -> %02x\n", *valuep, newValue); 2590 *valuep = newValue; 2591 return 0; 2592 } 2593 2594 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type, 2595 struct usb_os_desc_header *h, void *data, 2596 unsigned len, void *priv) 2597 { 2598 struct ffs_function *func = priv; 2599 u8 length = 0; 2600 2601 switch (type) { 2602 case FFS_OS_DESC_EXT_COMPAT: { 2603 struct usb_ext_compat_desc *desc = data; 2604 struct usb_os_desc_table *t; 2605 2606 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber]; 2607 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber]; 2608 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID, 2609 ARRAY_SIZE(desc->CompatibleID) + 2610 ARRAY_SIZE(desc->SubCompatibleID)); 2611 length = sizeof(*desc); 2612 } 2613 break; 2614 case FFS_OS_DESC_EXT_PROP: { 2615 struct usb_ext_prop_desc *desc = data; 2616 struct usb_os_desc_table *t; 2617 struct usb_os_desc_ext_prop *ext_prop; 2618 char *ext_prop_name; 2619 char *ext_prop_data; 2620 2621 t = &func->function.os_desc_table[h->interface]; 2622 t->if_id = func->interfaces_nums[h->interface]; 2623 2624 ext_prop = func->ffs->ms_os_descs_ext_prop_avail; 2625 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop); 2626 2627 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType); 2628 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength); 2629 ext_prop->data_len = le32_to_cpu(*(u32 *) 2630 usb_ext_prop_data_len_ptr(data, ext_prop->name_len)); 2631 length = ext_prop->name_len + ext_prop->data_len + 14; 2632 2633 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail; 2634 func->ffs->ms_os_descs_ext_prop_name_avail += 2635 ext_prop->name_len; 2636 2637 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail; 2638 func->ffs->ms_os_descs_ext_prop_data_avail += 2639 ext_prop->data_len; 2640 memcpy(ext_prop_data, 2641 usb_ext_prop_data_ptr(data, ext_prop->name_len), 2642 ext_prop->data_len); 2643 /* unicode data reported to the host as "WCHAR"s */ 2644 switch (ext_prop->type) { 2645 case USB_EXT_PROP_UNICODE: 2646 case USB_EXT_PROP_UNICODE_ENV: 2647 case USB_EXT_PROP_UNICODE_LINK: 2648 case USB_EXT_PROP_UNICODE_MULTI: 2649 ext_prop->data_len *= 2; 2650 break; 2651 } 2652 ext_prop->data = ext_prop_data; 2653 2654 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data), 2655 ext_prop->name_len); 2656 /* property name reported to the host as "WCHAR"s */ 2657 ext_prop->name_len *= 2; 2658 ext_prop->name = ext_prop_name; 2659 2660 t->os_desc->ext_prop_len += 2661 ext_prop->name_len + ext_prop->data_len + 14; 2662 ++t->os_desc->ext_prop_count; 2663 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop); 2664 } 2665 break; 2666 default: 2667 pr_vdebug("unknown descriptor: %d\n", type); 2668 } 2669 2670 return length; 2671 } 2672 2673 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, 2674 struct usb_configuration *c) 2675 { 2676 struct ffs_function *func = ffs_func_from_usb(f); 2677 struct f_fs_opts *ffs_opts = 2678 container_of(f->fi, struct f_fs_opts, func_inst); 2679 int ret; 2680 2681 ENTER(); 2682 2683 /* 2684 * Legacy gadget triggers binding in functionfs_ready_callback, 2685 * which already uses locking; taking the same lock here would 2686 * cause a deadlock. 2687 * 2688 * Configfs-enabled gadgets however do need ffs_dev_lock. 2689 */ 2690 if (!ffs_opts->no_configfs) 2691 ffs_dev_lock(); 2692 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV; 2693 func->ffs = ffs_opts->dev->ffs_data; 2694 if (!ffs_opts->no_configfs) 2695 ffs_dev_unlock(); 2696 if (ret) 2697 return ERR_PTR(ret); 2698 2699 func->conf = c; 2700 func->gadget = c->cdev->gadget; 2701 2702 /* 2703 * in drivers/usb/gadget/configfs.c:configfs_composite_bind() 2704 * configurations are bound in sequence with list_for_each_entry, 2705 * in each configuration its functions are bound in sequence 2706 * with list_for_each_entry, so we assume no race condition 2707 * with regard to ffs_opts->bound access 2708 */ 2709 if (!ffs_opts->refcnt) { 2710 ret = functionfs_bind(func->ffs, c->cdev); 2711 if (ret) 2712 return ERR_PTR(ret); 2713 } 2714 ffs_opts->refcnt++; 2715 func->function.strings = func->ffs->stringtabs; 2716 2717 return ffs_opts; 2718 } 2719 2720 static int _ffs_func_bind(struct usb_configuration *c, 2721 struct usb_function *f) 2722 { 2723 struct ffs_function *func = ffs_func_from_usb(f); 2724 struct ffs_data *ffs = func->ffs; 2725 2726 const int full = !!func->ffs->fs_descs_count; 2727 const int high = gadget_is_dualspeed(func->gadget) && 2728 func->ffs->hs_descs_count; 2729 const int super = gadget_is_superspeed(func->gadget) && 2730 func->ffs->ss_descs_count; 2731 2732 int fs_len, hs_len, ss_len, ret, i; 2733 2734 /* Make it a single chunk, less management later on */ 2735 vla_group(d); 2736 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count); 2737 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs, 2738 full ? ffs->fs_descs_count + 1 : 0); 2739 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs, 2740 high ? ffs->hs_descs_count + 1 : 0); 2741 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs, 2742 super ? ffs->ss_descs_count + 1 : 0); 2743 vla_item_with_sz(d, short, inums, ffs->interfaces_count); 2744 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table, 2745 c->cdev->use_os_string ? ffs->interfaces_count : 0); 2746 vla_item_with_sz(d, char[16], ext_compat, 2747 c->cdev->use_os_string ? ffs->interfaces_count : 0); 2748 vla_item_with_sz(d, struct usb_os_desc, os_desc, 2749 c->cdev->use_os_string ? ffs->interfaces_count : 0); 2750 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop, 2751 ffs->ms_os_descs_ext_prop_count); 2752 vla_item_with_sz(d, char, ext_prop_name, 2753 ffs->ms_os_descs_ext_prop_name_len); 2754 vla_item_with_sz(d, char, ext_prop_data, 2755 ffs->ms_os_descs_ext_prop_data_len); 2756 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length); 2757 char *vlabuf; 2758 2759 ENTER(); 2760 2761 /* Has descriptors only for speeds gadget does not support */ 2762 if (unlikely(!(full | high | super))) 2763 return -ENOTSUPP; 2764 2765 /* Allocate a single chunk, less management later on */ 2766 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL); 2767 if (unlikely(!vlabuf)) 2768 return -ENOMEM; 2769 2770 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop); 2771 ffs->ms_os_descs_ext_prop_name_avail = 2772 vla_ptr(vlabuf, d, ext_prop_name); 2773 ffs->ms_os_descs_ext_prop_data_avail = 2774 vla_ptr(vlabuf, d, ext_prop_data); 2775 2776 /* Copy descriptors */ 2777 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs, 2778 ffs->raw_descs_length); 2779 2780 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz); 2781 for (ret = ffs->eps_count; ret; --ret) { 2782 struct ffs_ep *ptr; 2783 2784 ptr = vla_ptr(vlabuf, d, eps); 2785 ptr[ret].num = -1; 2786 } 2787 2788 /* Save pointers 2789 * d_eps == vlabuf, func->eps used to kfree vlabuf later 2790 */ 2791 func->eps = vla_ptr(vlabuf, d, eps); 2792 func->interfaces_nums = vla_ptr(vlabuf, d, inums); 2793 2794 /* 2795 * Go through all the endpoint descriptors and allocate 2796 * endpoints first, so that later we can rewrite the endpoint 2797 * numbers without worrying that it may be described later on. 2798 */ 2799 if (likely(full)) { 2800 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs); 2801 fs_len = ffs_do_descs(ffs->fs_descs_count, 2802 vla_ptr(vlabuf, d, raw_descs), 2803 d_raw_descs__sz, 2804 __ffs_func_bind_do_descs, func); 2805 if (unlikely(fs_len < 0)) { 2806 ret = fs_len; 2807 goto error; 2808 } 2809 } else { 2810 fs_len = 0; 2811 } 2812 2813 if (likely(high)) { 2814 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs); 2815 hs_len = ffs_do_descs(ffs->hs_descs_count, 2816 vla_ptr(vlabuf, d, raw_descs) + fs_len, 2817 d_raw_descs__sz - fs_len, 2818 __ffs_func_bind_do_descs, func); 2819 if (unlikely(hs_len < 0)) { 2820 ret = hs_len; 2821 goto error; 2822 } 2823 } else { 2824 hs_len = 0; 2825 } 2826 2827 if (likely(super)) { 2828 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs); 2829 ss_len = ffs_do_descs(ffs->ss_descs_count, 2830 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len, 2831 d_raw_descs__sz - fs_len - hs_len, 2832 __ffs_func_bind_do_descs, func); 2833 if (unlikely(ss_len < 0)) { 2834 ret = ss_len; 2835 goto error; 2836 } 2837 } else { 2838 ss_len = 0; 2839 } 2840 2841 /* 2842 * Now handle interface numbers allocation and interface and 2843 * endpoint numbers rewriting. We can do that in one go 2844 * now. 2845 */ 2846 ret = ffs_do_descs(ffs->fs_descs_count + 2847 (high ? ffs->hs_descs_count : 0) + 2848 (super ? ffs->ss_descs_count : 0), 2849 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz, 2850 __ffs_func_bind_do_nums, func); 2851 if (unlikely(ret < 0)) 2852 goto error; 2853 2854 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table); 2855 if (c->cdev->use_os_string) 2856 for (i = 0; i < ffs->interfaces_count; ++i) { 2857 struct usb_os_desc *desc; 2858 2859 desc = func->function.os_desc_table[i].os_desc = 2860 vla_ptr(vlabuf, d, os_desc) + 2861 i * sizeof(struct usb_os_desc); 2862 desc->ext_compat_id = 2863 vla_ptr(vlabuf, d, ext_compat) + i * 16; 2864 INIT_LIST_HEAD(&desc->ext_prop); 2865 } 2866 ret = ffs_do_os_descs(ffs->ms_os_descs_count, 2867 vla_ptr(vlabuf, d, raw_descs) + 2868 fs_len + hs_len + ss_len, 2869 d_raw_descs__sz - fs_len - hs_len - ss_len, 2870 __ffs_func_bind_do_os_desc, func); 2871 if (unlikely(ret < 0)) 2872 goto error; 2873 func->function.os_desc_n = 2874 c->cdev->use_os_string ? ffs->interfaces_count : 0; 2875 2876 /* And we're done */ 2877 ffs_event_add(ffs, FUNCTIONFS_BIND); 2878 return 0; 2879 2880 error: 2881 /* XXX Do we need to release all claimed endpoints here? */ 2882 return ret; 2883 } 2884 2885 static int ffs_func_bind(struct usb_configuration *c, 2886 struct usb_function *f) 2887 { 2888 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c); 2889 struct ffs_function *func = ffs_func_from_usb(f); 2890 int ret; 2891 2892 if (IS_ERR(ffs_opts)) 2893 return PTR_ERR(ffs_opts); 2894 2895 ret = _ffs_func_bind(c, f); 2896 if (ret && !--ffs_opts->refcnt) 2897 functionfs_unbind(func->ffs); 2898 2899 return ret; 2900 } 2901 2902 2903 /* Other USB function hooks *************************************************/ 2904 2905 static void ffs_reset_work(struct work_struct *work) 2906 { 2907 struct ffs_data *ffs = container_of(work, 2908 struct ffs_data, reset_work); 2909 ffs_data_reset(ffs); 2910 } 2911 2912 static int ffs_func_set_alt(struct usb_function *f, 2913 unsigned interface, unsigned alt) 2914 { 2915 struct ffs_function *func = ffs_func_from_usb(f); 2916 struct ffs_data *ffs = func->ffs; 2917 int ret = 0, intf; 2918 2919 if (alt != (unsigned)-1) { 2920 intf = ffs_func_revmap_intf(func, interface); 2921 if (unlikely(intf < 0)) 2922 return intf; 2923 } 2924 2925 if (ffs->func) 2926 ffs_func_eps_disable(ffs->func); 2927 2928 if (ffs->state == FFS_DEACTIVATED) { 2929 ffs->state = FFS_CLOSING; 2930 INIT_WORK(&ffs->reset_work, ffs_reset_work); 2931 schedule_work(&ffs->reset_work); 2932 return -ENODEV; 2933 } 2934 2935 if (ffs->state != FFS_ACTIVE) 2936 return -ENODEV; 2937 2938 if (alt == (unsigned)-1) { 2939 ffs->func = NULL; 2940 ffs_event_add(ffs, FUNCTIONFS_DISABLE); 2941 return 0; 2942 } 2943 2944 ffs->func = func; 2945 ret = ffs_func_eps_enable(func); 2946 if (likely(ret >= 0)) 2947 ffs_event_add(ffs, FUNCTIONFS_ENABLE); 2948 return ret; 2949 } 2950 2951 static void ffs_func_disable(struct usb_function *f) 2952 { 2953 ffs_func_set_alt(f, 0, (unsigned)-1); 2954 } 2955 2956 static int ffs_func_setup(struct usb_function *f, 2957 const struct usb_ctrlrequest *creq) 2958 { 2959 struct ffs_function *func = ffs_func_from_usb(f); 2960 struct ffs_data *ffs = func->ffs; 2961 unsigned long flags; 2962 int ret; 2963 2964 ENTER(); 2965 2966 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType); 2967 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest); 2968 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue)); 2969 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex)); 2970 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength)); 2971 2972 /* 2973 * Most requests directed to interface go through here 2974 * (notable exceptions are set/get interface) so we need to 2975 * handle them. All other either handled by composite or 2976 * passed to usb_configuration->setup() (if one is set). No 2977 * matter, we will handle requests directed to endpoint here 2978 * as well (as it's straightforward) but what to do with any 2979 * other request? 2980 */ 2981 if (ffs->state != FFS_ACTIVE) 2982 return -ENODEV; 2983 2984 switch (creq->bRequestType & USB_RECIP_MASK) { 2985 case USB_RECIP_INTERFACE: 2986 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex)); 2987 if (unlikely(ret < 0)) 2988 return ret; 2989 break; 2990 2991 case USB_RECIP_ENDPOINT: 2992 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex)); 2993 if (unlikely(ret < 0)) 2994 return ret; 2995 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 2996 ret = func->ffs->eps_addrmap[ret]; 2997 break; 2998 2999 default: 3000 return -EOPNOTSUPP; 3001 } 3002 3003 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 3004 ffs->ev.setup = *creq; 3005 ffs->ev.setup.wIndex = cpu_to_le16(ret); 3006 __ffs_event_add(ffs, FUNCTIONFS_SETUP); 3007 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 3008 3009 return 0; 3010 } 3011 3012 static void ffs_func_suspend(struct usb_function *f) 3013 { 3014 ENTER(); 3015 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND); 3016 } 3017 3018 static void ffs_func_resume(struct usb_function *f) 3019 { 3020 ENTER(); 3021 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME); 3022 } 3023 3024 3025 /* Endpoint and interface numbers reverse mapping ***************************/ 3026 3027 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) 3028 { 3029 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK]; 3030 return num ? num : -EDOM; 3031 } 3032 3033 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) 3034 { 3035 short *nums = func->interfaces_nums; 3036 unsigned count = func->ffs->interfaces_count; 3037 3038 for (; count; --count, ++nums) { 3039 if (*nums >= 0 && *nums == intf) 3040 return nums - func->interfaces_nums; 3041 } 3042 3043 return -EDOM; 3044 } 3045 3046 3047 /* Devices management *******************************************************/ 3048 3049 static LIST_HEAD(ffs_devices); 3050 3051 static struct ffs_dev *_ffs_do_find_dev(const char *name) 3052 { 3053 struct ffs_dev *dev; 3054 3055 list_for_each_entry(dev, &ffs_devices, entry) { 3056 if (!dev->name || !name) 3057 continue; 3058 if (strcmp(dev->name, name) == 0) 3059 return dev; 3060 } 3061 3062 return NULL; 3063 } 3064 3065 /* 3066 * ffs_lock must be taken by the caller of this function 3067 */ 3068 static struct ffs_dev *_ffs_get_single_dev(void) 3069 { 3070 struct ffs_dev *dev; 3071 3072 if (list_is_singular(&ffs_devices)) { 3073 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry); 3074 if (dev->single) 3075 return dev; 3076 } 3077 3078 return NULL; 3079 } 3080 3081 /* 3082 * ffs_lock must be taken by the caller of this function 3083 */ 3084 static struct ffs_dev *_ffs_find_dev(const char *name) 3085 { 3086 struct ffs_dev *dev; 3087 3088 dev = _ffs_get_single_dev(); 3089 if (dev) 3090 return dev; 3091 3092 return _ffs_do_find_dev(name); 3093 } 3094 3095 /* Configfs support *********************************************************/ 3096 3097 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item) 3098 { 3099 return container_of(to_config_group(item), struct f_fs_opts, 3100 func_inst.group); 3101 } 3102 3103 static void ffs_attr_release(struct config_item *item) 3104 { 3105 struct f_fs_opts *opts = to_ffs_opts(item); 3106 3107 usb_put_function_instance(&opts->func_inst); 3108 } 3109 3110 static struct configfs_item_operations ffs_item_ops = { 3111 .release = ffs_attr_release, 3112 }; 3113 3114 static struct config_item_type ffs_func_type = { 3115 .ct_item_ops = &ffs_item_ops, 3116 .ct_owner = THIS_MODULE, 3117 }; 3118 3119 3120 /* Function registration interface ******************************************/ 3121 3122 static void ffs_free_inst(struct usb_function_instance *f) 3123 { 3124 struct f_fs_opts *opts; 3125 3126 opts = to_f_fs_opts(f); 3127 ffs_dev_lock(); 3128 _ffs_free_dev(opts->dev); 3129 ffs_dev_unlock(); 3130 kfree(opts); 3131 } 3132 3133 #define MAX_INST_NAME_LEN 40 3134 3135 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name) 3136 { 3137 struct f_fs_opts *opts; 3138 char *ptr; 3139 const char *tmp; 3140 int name_len, ret; 3141 3142 name_len = strlen(name) + 1; 3143 if (name_len > MAX_INST_NAME_LEN) 3144 return -ENAMETOOLONG; 3145 3146 ptr = kstrndup(name, name_len, GFP_KERNEL); 3147 if (!ptr) 3148 return -ENOMEM; 3149 3150 opts = to_f_fs_opts(fi); 3151 tmp = NULL; 3152 3153 ffs_dev_lock(); 3154 3155 tmp = opts->dev->name_allocated ? opts->dev->name : NULL; 3156 ret = _ffs_name_dev(opts->dev, ptr); 3157 if (ret) { 3158 kfree(ptr); 3159 ffs_dev_unlock(); 3160 return ret; 3161 } 3162 opts->dev->name_allocated = true; 3163 3164 ffs_dev_unlock(); 3165 3166 kfree(tmp); 3167 3168 return 0; 3169 } 3170 3171 static struct usb_function_instance *ffs_alloc_inst(void) 3172 { 3173 struct f_fs_opts *opts; 3174 struct ffs_dev *dev; 3175 3176 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 3177 if (!opts) 3178 return ERR_PTR(-ENOMEM); 3179 3180 opts->func_inst.set_inst_name = ffs_set_inst_name; 3181 opts->func_inst.free_func_inst = ffs_free_inst; 3182 ffs_dev_lock(); 3183 dev = _ffs_alloc_dev(); 3184 ffs_dev_unlock(); 3185 if (IS_ERR(dev)) { 3186 kfree(opts); 3187 return ERR_CAST(dev); 3188 } 3189 opts->dev = dev; 3190 dev->opts = opts; 3191 3192 config_group_init_type_name(&opts->func_inst.group, "", 3193 &ffs_func_type); 3194 return &opts->func_inst; 3195 } 3196 3197 static void ffs_free(struct usb_function *f) 3198 { 3199 kfree(ffs_func_from_usb(f)); 3200 } 3201 3202 static void ffs_func_unbind(struct usb_configuration *c, 3203 struct usb_function *f) 3204 { 3205 struct ffs_function *func = ffs_func_from_usb(f); 3206 struct ffs_data *ffs = func->ffs; 3207 struct f_fs_opts *opts = 3208 container_of(f->fi, struct f_fs_opts, func_inst); 3209 struct ffs_ep *ep = func->eps; 3210 unsigned count = ffs->eps_count; 3211 unsigned long flags; 3212 3213 ENTER(); 3214 if (ffs->func == func) { 3215 ffs_func_eps_disable(func); 3216 ffs->func = NULL; 3217 } 3218 3219 if (!--opts->refcnt) 3220 functionfs_unbind(ffs); 3221 3222 /* cleanup after autoconfig */ 3223 spin_lock_irqsave(&func->ffs->eps_lock, flags); 3224 do { 3225 if (ep->ep && ep->req) 3226 usb_ep_free_request(ep->ep, ep->req); 3227 ep->req = NULL; 3228 ++ep; 3229 } while (--count); 3230 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 3231 kfree(func->eps); 3232 func->eps = NULL; 3233 /* 3234 * eps, descriptors and interfaces_nums are allocated in the 3235 * same chunk so only one free is required. 3236 */ 3237 func->function.fs_descriptors = NULL; 3238 func->function.hs_descriptors = NULL; 3239 func->function.ss_descriptors = NULL; 3240 func->interfaces_nums = NULL; 3241 3242 ffs_event_add(ffs, FUNCTIONFS_UNBIND); 3243 } 3244 3245 static struct usb_function *ffs_alloc(struct usb_function_instance *fi) 3246 { 3247 struct ffs_function *func; 3248 3249 ENTER(); 3250 3251 func = kzalloc(sizeof(*func), GFP_KERNEL); 3252 if (unlikely(!func)) 3253 return ERR_PTR(-ENOMEM); 3254 3255 func->function.name = "Function FS Gadget"; 3256 3257 func->function.bind = ffs_func_bind; 3258 func->function.unbind = ffs_func_unbind; 3259 func->function.set_alt = ffs_func_set_alt; 3260 func->function.disable = ffs_func_disable; 3261 func->function.setup = ffs_func_setup; 3262 func->function.suspend = ffs_func_suspend; 3263 func->function.resume = ffs_func_resume; 3264 func->function.free_func = ffs_free; 3265 3266 return &func->function; 3267 } 3268 3269 /* 3270 * ffs_lock must be taken by the caller of this function 3271 */ 3272 static struct ffs_dev *_ffs_alloc_dev(void) 3273 { 3274 struct ffs_dev *dev; 3275 int ret; 3276 3277 if (_ffs_get_single_dev()) 3278 return ERR_PTR(-EBUSY); 3279 3280 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 3281 if (!dev) 3282 return ERR_PTR(-ENOMEM); 3283 3284 if (list_empty(&ffs_devices)) { 3285 ret = functionfs_init(); 3286 if (ret) { 3287 kfree(dev); 3288 return ERR_PTR(ret); 3289 } 3290 } 3291 3292 list_add(&dev->entry, &ffs_devices); 3293 3294 return dev; 3295 } 3296 3297 /* 3298 * ffs_lock must be taken by the caller of this function 3299 * The caller is responsible for "name" being available whenever f_fs needs it 3300 */ 3301 static int _ffs_name_dev(struct ffs_dev *dev, const char *name) 3302 { 3303 struct ffs_dev *existing; 3304 3305 existing = _ffs_do_find_dev(name); 3306 if (existing) 3307 return -EBUSY; 3308 3309 dev->name = name; 3310 3311 return 0; 3312 } 3313 3314 /* 3315 * The caller is responsible for "name" being available whenever f_fs needs it 3316 */ 3317 int ffs_name_dev(struct ffs_dev *dev, const char *name) 3318 { 3319 int ret; 3320 3321 ffs_dev_lock(); 3322 ret = _ffs_name_dev(dev, name); 3323 ffs_dev_unlock(); 3324 3325 return ret; 3326 } 3327 EXPORT_SYMBOL_GPL(ffs_name_dev); 3328 3329 int ffs_single_dev(struct ffs_dev *dev) 3330 { 3331 int ret; 3332 3333 ret = 0; 3334 ffs_dev_lock(); 3335 3336 if (!list_is_singular(&ffs_devices)) 3337 ret = -EBUSY; 3338 else 3339 dev->single = true; 3340 3341 ffs_dev_unlock(); 3342 return ret; 3343 } 3344 EXPORT_SYMBOL_GPL(ffs_single_dev); 3345 3346 /* 3347 * ffs_lock must be taken by the caller of this function 3348 */ 3349 static void _ffs_free_dev(struct ffs_dev *dev) 3350 { 3351 list_del(&dev->entry); 3352 if (dev->name_allocated) 3353 kfree(dev->name); 3354 kfree(dev); 3355 if (list_empty(&ffs_devices)) 3356 functionfs_cleanup(); 3357 } 3358 3359 static void *ffs_acquire_dev(const char *dev_name) 3360 { 3361 struct ffs_dev *ffs_dev; 3362 3363 ENTER(); 3364 ffs_dev_lock(); 3365 3366 ffs_dev = _ffs_find_dev(dev_name); 3367 if (!ffs_dev) 3368 ffs_dev = ERR_PTR(-ENOENT); 3369 else if (ffs_dev->mounted) 3370 ffs_dev = ERR_PTR(-EBUSY); 3371 else if (ffs_dev->ffs_acquire_dev_callback && 3372 ffs_dev->ffs_acquire_dev_callback(ffs_dev)) 3373 ffs_dev = ERR_PTR(-ENOENT); 3374 else 3375 ffs_dev->mounted = true; 3376 3377 ffs_dev_unlock(); 3378 return ffs_dev; 3379 } 3380 3381 static void ffs_release_dev(struct ffs_data *ffs_data) 3382 { 3383 struct ffs_dev *ffs_dev; 3384 3385 ENTER(); 3386 ffs_dev_lock(); 3387 3388 ffs_dev = ffs_data->private_data; 3389 if (ffs_dev) { 3390 ffs_dev->mounted = false; 3391 3392 if (ffs_dev->ffs_release_dev_callback) 3393 ffs_dev->ffs_release_dev_callback(ffs_dev); 3394 } 3395 3396 ffs_dev_unlock(); 3397 } 3398 3399 static int ffs_ready(struct ffs_data *ffs) 3400 { 3401 struct ffs_dev *ffs_obj; 3402 int ret = 0; 3403 3404 ENTER(); 3405 ffs_dev_lock(); 3406 3407 ffs_obj = ffs->private_data; 3408 if (!ffs_obj) { 3409 ret = -EINVAL; 3410 goto done; 3411 } 3412 if (WARN_ON(ffs_obj->desc_ready)) { 3413 ret = -EBUSY; 3414 goto done; 3415 } 3416 3417 ffs_obj->desc_ready = true; 3418 ffs_obj->ffs_data = ffs; 3419 3420 if (ffs_obj->ffs_ready_callback) { 3421 ret = ffs_obj->ffs_ready_callback(ffs); 3422 if (ret) 3423 goto done; 3424 } 3425 3426 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags); 3427 done: 3428 ffs_dev_unlock(); 3429 return ret; 3430 } 3431 3432 static void ffs_closed(struct ffs_data *ffs) 3433 { 3434 struct ffs_dev *ffs_obj; 3435 struct f_fs_opts *opts; 3436 3437 ENTER(); 3438 ffs_dev_lock(); 3439 3440 ffs_obj = ffs->private_data; 3441 if (!ffs_obj) 3442 goto done; 3443 3444 ffs_obj->desc_ready = false; 3445 3446 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && 3447 ffs_obj->ffs_closed_callback) 3448 ffs_obj->ffs_closed_callback(ffs); 3449 3450 if (ffs_obj->opts) 3451 opts = ffs_obj->opts; 3452 else 3453 goto done; 3454 3455 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent 3456 || !atomic_read(&opts->func_inst.group.cg_item.ci_kref.refcount)) 3457 goto done; 3458 3459 unregister_gadget_item(ffs_obj->opts-> 3460 func_inst.group.cg_item.ci_parent->ci_parent); 3461 done: 3462 ffs_dev_unlock(); 3463 } 3464 3465 /* Misc helper functions ****************************************************/ 3466 3467 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 3468 { 3469 return nonblock 3470 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN 3471 : mutex_lock_interruptible(mutex); 3472 } 3473 3474 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 3475 { 3476 char *data; 3477 3478 if (unlikely(!len)) 3479 return NULL; 3480 3481 data = kmalloc(len, GFP_KERNEL); 3482 if (unlikely(!data)) 3483 return ERR_PTR(-ENOMEM); 3484 3485 if (unlikely(copy_from_user(data, buf, len))) { 3486 kfree(data); 3487 return ERR_PTR(-EFAULT); 3488 } 3489 3490 pr_vdebug("Buffer from user space:\n"); 3491 ffs_dump_mem("", data, len); 3492 3493 return data; 3494 } 3495 3496 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc); 3497 MODULE_LICENSE("GPL"); 3498 MODULE_AUTHOR("Michal Nazarewicz"); 3499