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/sched/signal.h> 27 #include <linux/uio.h> 28 #include <asm/unaligned.h> 29 30 #include <linux/usb/composite.h> 31 #include <linux/usb/functionfs.h> 32 33 #include <linux/aio.h> 34 #include <linux/mmu_context.h> 35 #include <linux/poll.h> 36 #include <linux/eventfd.h> 37 38 #include "u_fs.h" 39 #include "u_f.h" 40 #include "u_os_desc.h" 41 #include "configfs.h" 42 43 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ 44 45 /* Reference counter handling */ 46 static void ffs_data_get(struct ffs_data *ffs); 47 static void ffs_data_put(struct ffs_data *ffs); 48 /* Creates new ffs_data object. */ 49 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc)); 50 51 /* Opened counter handling. */ 52 static void ffs_data_opened(struct ffs_data *ffs); 53 static void ffs_data_closed(struct ffs_data *ffs); 54 55 /* Called with ffs->mutex held; take over ownership of data. */ 56 static int __must_check 57 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len); 58 static int __must_check 59 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len); 60 61 62 /* The function structure ***************************************************/ 63 64 struct ffs_ep; 65 66 struct ffs_function { 67 struct usb_configuration *conf; 68 struct usb_gadget *gadget; 69 struct ffs_data *ffs; 70 71 struct ffs_ep *eps; 72 u8 eps_revmap[16]; 73 short *interfaces_nums; 74 75 struct usb_function function; 76 }; 77 78 79 static struct ffs_function *ffs_func_from_usb(struct usb_function *f) 80 { 81 return container_of(f, struct ffs_function, function); 82 } 83 84 85 static inline enum ffs_setup_state 86 ffs_setup_state_clear_cancelled(struct ffs_data *ffs) 87 { 88 return (enum ffs_setup_state) 89 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP); 90 } 91 92 93 static void ffs_func_eps_disable(struct ffs_function *func); 94 static int __must_check ffs_func_eps_enable(struct ffs_function *func); 95 96 static int ffs_func_bind(struct usb_configuration *, 97 struct usb_function *); 98 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned); 99 static void ffs_func_disable(struct usb_function *); 100 static int ffs_func_setup(struct usb_function *, 101 const struct usb_ctrlrequest *); 102 static bool ffs_func_req_match(struct usb_function *, 103 const struct usb_ctrlrequest *, 104 bool config0); 105 static void ffs_func_suspend(struct usb_function *); 106 static void ffs_func_resume(struct usb_function *); 107 108 109 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num); 110 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf); 111 112 113 /* The endpoints structures *************************************************/ 114 115 struct ffs_ep { 116 struct usb_ep *ep; /* P: ffs->eps_lock */ 117 struct usb_request *req; /* P: epfile->mutex */ 118 119 /* [0]: full speed, [1]: high speed, [2]: super speed */ 120 struct usb_endpoint_descriptor *descs[3]; 121 122 u8 num; 123 124 int status; /* P: epfile->mutex */ 125 }; 126 127 struct ffs_epfile { 128 /* Protects ep->ep and ep->req. */ 129 struct mutex mutex; 130 wait_queue_head_t wait; 131 132 struct ffs_data *ffs; 133 struct ffs_ep *ep; /* P: ffs->eps_lock */ 134 135 struct dentry *dentry; 136 137 /* 138 * Buffer for holding data from partial reads which may happen since 139 * we’re rounding user read requests to a multiple of a max packet size. 140 * 141 * The pointer is initialised with NULL value and may be set by 142 * __ffs_epfile_read_data function to point to a temporary buffer. 143 * 144 * In normal operation, calls to __ffs_epfile_read_buffered will consume 145 * data from said buffer and eventually free it. Importantly, while the 146 * function is using the buffer, it sets the pointer to NULL. This is 147 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered 148 * can never run concurrently (they are synchronised by epfile->mutex) 149 * so the latter will not assign a new value to the pointer. 150 * 151 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is 152 * valid) and sets the pointer to READ_BUFFER_DROP value. This special 153 * value is crux of the synchronisation between ffs_func_eps_disable and 154 * __ffs_epfile_read_data. 155 * 156 * Once __ffs_epfile_read_data is about to finish it will try to set the 157 * pointer back to its old value (as described above), but seeing as the 158 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free 159 * the buffer. 160 * 161 * == State transitions == 162 * 163 * • ptr == NULL: (initial state) 164 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP 165 * ◦ __ffs_epfile_read_buffered: nop 166 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf 167 * ◦ reading finishes: n/a, not in ‘and reading’ state 168 * • ptr == DROP: 169 * ◦ __ffs_epfile_read_buffer_free: nop 170 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL 171 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop 172 * ◦ reading finishes: n/a, not in ‘and reading’ state 173 * • ptr == buf: 174 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP 175 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading 176 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered 177 * is always called first 178 * ◦ reading finishes: n/a, not in ‘and reading’ state 179 * • ptr == NULL and reading: 180 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading 181 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held 182 * ◦ __ffs_epfile_read_data: n/a, mutex is held 183 * ◦ reading finishes and … 184 * … all data read: free buf, go to ptr == NULL 185 * … otherwise: go to ptr == buf and reading 186 * • ptr == DROP and reading: 187 * ◦ __ffs_epfile_read_buffer_free: nop 188 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held 189 * ◦ __ffs_epfile_read_data: n/a, mutex is held 190 * ◦ reading finishes: free buf, go to ptr == DROP 191 */ 192 struct ffs_buffer *read_buffer; 193 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN)) 194 195 char name[5]; 196 197 unsigned char in; /* P: ffs->eps_lock */ 198 unsigned char isoc; /* P: ffs->eps_lock */ 199 200 unsigned char _pad; 201 }; 202 203 struct ffs_buffer { 204 size_t length; 205 char *data; 206 char storage[]; 207 }; 208 209 /* ffs_io_data structure ***************************************************/ 210 211 struct ffs_io_data { 212 bool aio; 213 bool read; 214 215 struct kiocb *kiocb; 216 struct iov_iter data; 217 const void *to_free; 218 char *buf; 219 220 struct mm_struct *mm; 221 struct work_struct work; 222 223 struct usb_ep *ep; 224 struct usb_request *req; 225 226 struct ffs_data *ffs; 227 }; 228 229 struct ffs_desc_helper { 230 struct ffs_data *ffs; 231 unsigned interfaces_count; 232 unsigned eps_count; 233 }; 234 235 static int __must_check ffs_epfiles_create(struct ffs_data *ffs); 236 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count); 237 238 static struct dentry * 239 ffs_sb_create_file(struct super_block *sb, const char *name, void *data, 240 const struct file_operations *fops); 241 242 /* Devices management *******************************************************/ 243 244 DEFINE_MUTEX(ffs_lock); 245 EXPORT_SYMBOL_GPL(ffs_lock); 246 247 static struct ffs_dev *_ffs_find_dev(const char *name); 248 static struct ffs_dev *_ffs_alloc_dev(void); 249 static int _ffs_name_dev(struct ffs_dev *dev, const char *name); 250 static void _ffs_free_dev(struct ffs_dev *dev); 251 static void *ffs_acquire_dev(const char *dev_name); 252 static void ffs_release_dev(struct ffs_data *ffs_data); 253 static int ffs_ready(struct ffs_data *ffs); 254 static void ffs_closed(struct ffs_data *ffs); 255 256 /* Misc helper functions ****************************************************/ 257 258 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 259 __attribute__((warn_unused_result, nonnull)); 260 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 261 __attribute__((warn_unused_result, nonnull)); 262 263 264 /* Control file aka ep0 *****************************************************/ 265 266 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req) 267 { 268 struct ffs_data *ffs = req->context; 269 270 complete(&ffs->ep0req_completion); 271 } 272 273 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len) 274 { 275 struct usb_request *req = ffs->ep0req; 276 int ret; 277 278 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength); 279 280 spin_unlock_irq(&ffs->ev.waitq.lock); 281 282 req->buf = data; 283 req->length = len; 284 285 /* 286 * UDC layer requires to provide a buffer even for ZLP, but should 287 * not use it at all. Let's provide some poisoned pointer to catch 288 * possible bug in the driver. 289 */ 290 if (req->buf == NULL) 291 req->buf = (void *)0xDEADBABE; 292 293 reinit_completion(&ffs->ep0req_completion); 294 295 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC); 296 if (unlikely(ret < 0)) 297 return ret; 298 299 ret = wait_for_completion_interruptible(&ffs->ep0req_completion); 300 if (unlikely(ret)) { 301 usb_ep_dequeue(ffs->gadget->ep0, req); 302 return -EINTR; 303 } 304 305 ffs->setup_state = FFS_NO_SETUP; 306 return req->status ? req->status : req->actual; 307 } 308 309 static int __ffs_ep0_stall(struct ffs_data *ffs) 310 { 311 if (ffs->ev.can_stall) { 312 pr_vdebug("ep0 stall\n"); 313 usb_ep_set_halt(ffs->gadget->ep0); 314 ffs->setup_state = FFS_NO_SETUP; 315 return -EL2HLT; 316 } else { 317 pr_debug("bogus ep0 stall!\n"); 318 return -ESRCH; 319 } 320 } 321 322 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, 323 size_t len, loff_t *ptr) 324 { 325 struct ffs_data *ffs = file->private_data; 326 ssize_t ret; 327 char *data; 328 329 ENTER(); 330 331 /* Fast check if setup was canceled */ 332 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 333 return -EIDRM; 334 335 /* Acquire mutex */ 336 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 337 if (unlikely(ret < 0)) 338 return ret; 339 340 /* Check state */ 341 switch (ffs->state) { 342 case FFS_READ_DESCRIPTORS: 343 case FFS_READ_STRINGS: 344 /* Copy data */ 345 if (unlikely(len < 16)) { 346 ret = -EINVAL; 347 break; 348 } 349 350 data = ffs_prepare_buffer(buf, len); 351 if (IS_ERR(data)) { 352 ret = PTR_ERR(data); 353 break; 354 } 355 356 /* Handle data */ 357 if (ffs->state == FFS_READ_DESCRIPTORS) { 358 pr_info("read descriptors\n"); 359 ret = __ffs_data_got_descs(ffs, data, len); 360 if (unlikely(ret < 0)) 361 break; 362 363 ffs->state = FFS_READ_STRINGS; 364 ret = len; 365 } else { 366 pr_info("read strings\n"); 367 ret = __ffs_data_got_strings(ffs, data, len); 368 if (unlikely(ret < 0)) 369 break; 370 371 ret = ffs_epfiles_create(ffs); 372 if (unlikely(ret)) { 373 ffs->state = FFS_CLOSING; 374 break; 375 } 376 377 ffs->state = FFS_ACTIVE; 378 mutex_unlock(&ffs->mutex); 379 380 ret = ffs_ready(ffs); 381 if (unlikely(ret < 0)) { 382 ffs->state = FFS_CLOSING; 383 return ret; 384 } 385 386 return len; 387 } 388 break; 389 390 case FFS_ACTIVE: 391 data = NULL; 392 /* 393 * We're called from user space, we can use _irq 394 * rather then _irqsave 395 */ 396 spin_lock_irq(&ffs->ev.waitq.lock); 397 switch (ffs_setup_state_clear_cancelled(ffs)) { 398 case FFS_SETUP_CANCELLED: 399 ret = -EIDRM; 400 goto done_spin; 401 402 case FFS_NO_SETUP: 403 ret = -ESRCH; 404 goto done_spin; 405 406 case FFS_SETUP_PENDING: 407 break; 408 } 409 410 /* FFS_SETUP_PENDING */ 411 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) { 412 spin_unlock_irq(&ffs->ev.waitq.lock); 413 ret = __ffs_ep0_stall(ffs); 414 break; 415 } 416 417 /* FFS_SETUP_PENDING and not stall */ 418 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); 419 420 spin_unlock_irq(&ffs->ev.waitq.lock); 421 422 data = ffs_prepare_buffer(buf, len); 423 if (IS_ERR(data)) { 424 ret = PTR_ERR(data); 425 break; 426 } 427 428 spin_lock_irq(&ffs->ev.waitq.lock); 429 430 /* 431 * We are guaranteed to be still in FFS_ACTIVE state 432 * but the state of setup could have changed from 433 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need 434 * to check for that. If that happened we copied data 435 * from user space in vain but it's unlikely. 436 * 437 * For sure we are not in FFS_NO_SETUP since this is 438 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP 439 * transition can be performed and it's protected by 440 * mutex. 441 */ 442 if (ffs_setup_state_clear_cancelled(ffs) == 443 FFS_SETUP_CANCELLED) { 444 ret = -EIDRM; 445 done_spin: 446 spin_unlock_irq(&ffs->ev.waitq.lock); 447 } else { 448 /* unlocks spinlock */ 449 ret = __ffs_ep0_queue_wait(ffs, data, len); 450 } 451 kfree(data); 452 break; 453 454 default: 455 ret = -EBADFD; 456 break; 457 } 458 459 mutex_unlock(&ffs->mutex); 460 return ret; 461 } 462 463 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */ 464 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf, 465 size_t n) 466 { 467 /* 468 * n cannot be bigger than ffs->ev.count, which cannot be bigger than 469 * size of ffs->ev.types array (which is four) so that's how much space 470 * we reserve. 471 */ 472 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)]; 473 const size_t size = n * sizeof *events; 474 unsigned i = 0; 475 476 memset(events, 0, size); 477 478 do { 479 events[i].type = ffs->ev.types[i]; 480 if (events[i].type == FUNCTIONFS_SETUP) { 481 events[i].u.setup = ffs->ev.setup; 482 ffs->setup_state = FFS_SETUP_PENDING; 483 } 484 } while (++i < n); 485 486 ffs->ev.count -= n; 487 if (ffs->ev.count) 488 memmove(ffs->ev.types, ffs->ev.types + n, 489 ffs->ev.count * sizeof *ffs->ev.types); 490 491 spin_unlock_irq(&ffs->ev.waitq.lock); 492 mutex_unlock(&ffs->mutex); 493 494 return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size; 495 } 496 497 static ssize_t ffs_ep0_read(struct file *file, char __user *buf, 498 size_t len, loff_t *ptr) 499 { 500 struct ffs_data *ffs = file->private_data; 501 char *data = NULL; 502 size_t n; 503 int ret; 504 505 ENTER(); 506 507 /* Fast check if setup was canceled */ 508 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 509 return -EIDRM; 510 511 /* Acquire mutex */ 512 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 513 if (unlikely(ret < 0)) 514 return ret; 515 516 /* Check state */ 517 if (ffs->state != FFS_ACTIVE) { 518 ret = -EBADFD; 519 goto done_mutex; 520 } 521 522 /* 523 * We're called from user space, we can use _irq rather then 524 * _irqsave 525 */ 526 spin_lock_irq(&ffs->ev.waitq.lock); 527 528 switch (ffs_setup_state_clear_cancelled(ffs)) { 529 case FFS_SETUP_CANCELLED: 530 ret = -EIDRM; 531 break; 532 533 case FFS_NO_SETUP: 534 n = len / sizeof(struct usb_functionfs_event); 535 if (unlikely(!n)) { 536 ret = -EINVAL; 537 break; 538 } 539 540 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) { 541 ret = -EAGAIN; 542 break; 543 } 544 545 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, 546 ffs->ev.count)) { 547 ret = -EINTR; 548 break; 549 } 550 551 return __ffs_ep0_read_events(ffs, buf, 552 min(n, (size_t)ffs->ev.count)); 553 554 case FFS_SETUP_PENDING: 555 if (ffs->ev.setup.bRequestType & USB_DIR_IN) { 556 spin_unlock_irq(&ffs->ev.waitq.lock); 557 ret = __ffs_ep0_stall(ffs); 558 goto done_mutex; 559 } 560 561 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); 562 563 spin_unlock_irq(&ffs->ev.waitq.lock); 564 565 if (likely(len)) { 566 data = kmalloc(len, GFP_KERNEL); 567 if (unlikely(!data)) { 568 ret = -ENOMEM; 569 goto done_mutex; 570 } 571 } 572 573 spin_lock_irq(&ffs->ev.waitq.lock); 574 575 /* See ffs_ep0_write() */ 576 if (ffs_setup_state_clear_cancelled(ffs) == 577 FFS_SETUP_CANCELLED) { 578 ret = -EIDRM; 579 break; 580 } 581 582 /* unlocks spinlock */ 583 ret = __ffs_ep0_queue_wait(ffs, data, len); 584 if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len))) 585 ret = -EFAULT; 586 goto done_mutex; 587 588 default: 589 ret = -EBADFD; 590 break; 591 } 592 593 spin_unlock_irq(&ffs->ev.waitq.lock); 594 done_mutex: 595 mutex_unlock(&ffs->mutex); 596 kfree(data); 597 return ret; 598 } 599 600 static int ffs_ep0_open(struct inode *inode, struct file *file) 601 { 602 struct ffs_data *ffs = inode->i_private; 603 604 ENTER(); 605 606 if (unlikely(ffs->state == FFS_CLOSING)) 607 return -EBUSY; 608 609 file->private_data = ffs; 610 ffs_data_opened(ffs); 611 612 return 0; 613 } 614 615 static int ffs_ep0_release(struct inode *inode, struct file *file) 616 { 617 struct ffs_data *ffs = file->private_data; 618 619 ENTER(); 620 621 ffs_data_closed(ffs); 622 623 return 0; 624 } 625 626 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) 627 { 628 struct ffs_data *ffs = file->private_data; 629 struct usb_gadget *gadget = ffs->gadget; 630 long ret; 631 632 ENTER(); 633 634 if (code == FUNCTIONFS_INTERFACE_REVMAP) { 635 struct ffs_function *func = ffs->func; 636 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV; 637 } else if (gadget && gadget->ops->ioctl) { 638 ret = gadget->ops->ioctl(gadget, code, value); 639 } else { 640 ret = -ENOTTY; 641 } 642 643 return ret; 644 } 645 646 static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait) 647 { 648 struct ffs_data *ffs = file->private_data; 649 unsigned int mask = POLLWRNORM; 650 int ret; 651 652 poll_wait(file, &ffs->ev.waitq, wait); 653 654 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 655 if (unlikely(ret < 0)) 656 return mask; 657 658 switch (ffs->state) { 659 case FFS_READ_DESCRIPTORS: 660 case FFS_READ_STRINGS: 661 mask |= POLLOUT; 662 break; 663 664 case FFS_ACTIVE: 665 switch (ffs->setup_state) { 666 case FFS_NO_SETUP: 667 if (ffs->ev.count) 668 mask |= POLLIN; 669 break; 670 671 case FFS_SETUP_PENDING: 672 case FFS_SETUP_CANCELLED: 673 mask |= (POLLIN | POLLOUT); 674 break; 675 } 676 case FFS_CLOSING: 677 break; 678 case FFS_DEACTIVATED: 679 break; 680 } 681 682 mutex_unlock(&ffs->mutex); 683 684 return mask; 685 } 686 687 static const struct file_operations ffs_ep0_operations = { 688 .llseek = no_llseek, 689 690 .open = ffs_ep0_open, 691 .write = ffs_ep0_write, 692 .read = ffs_ep0_read, 693 .release = ffs_ep0_release, 694 .unlocked_ioctl = ffs_ep0_ioctl, 695 .poll = ffs_ep0_poll, 696 }; 697 698 699 /* "Normal" endpoints operations ********************************************/ 700 701 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) 702 { 703 ENTER(); 704 if (likely(req->context)) { 705 struct ffs_ep *ep = _ep->driver_data; 706 ep->status = req->status ? req->status : req->actual; 707 complete(req->context); 708 } 709 } 710 711 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter) 712 { 713 ssize_t ret = copy_to_iter(data, data_len, iter); 714 if (likely(ret == data_len)) 715 return ret; 716 717 if (unlikely(iov_iter_count(iter))) 718 return -EFAULT; 719 720 /* 721 * Dear user space developer! 722 * 723 * TL;DR: To stop getting below error message in your kernel log, change 724 * user space code using functionfs to align read buffers to a max 725 * packet size. 726 * 727 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max 728 * packet size. When unaligned buffer is passed to functionfs, it 729 * internally uses a larger, aligned buffer so that such UDCs are happy. 730 * 731 * Unfortunately, this means that host may send more data than was 732 * requested in read(2) system call. f_fs doesn’t know what to do with 733 * that excess data so it simply drops it. 734 * 735 * Was the buffer aligned in the first place, no such problem would 736 * happen. 737 * 738 * Data may be dropped only in AIO reads. Synchronous reads are handled 739 * by splitting a request into multiple parts. This splitting may still 740 * be a problem though so it’s likely best to align the buffer 741 * regardless of it being AIO or not.. 742 * 743 * This only affects OUT endpoints, i.e. reading data with a read(2), 744 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not 745 * affected. 746 */ 747 pr_err("functionfs read size %d > requested size %zd, dropping excess data. " 748 "Align read buffer size to max packet size to avoid the problem.\n", 749 data_len, ret); 750 751 return ret; 752 } 753 754 static void ffs_user_copy_worker(struct work_struct *work) 755 { 756 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data, 757 work); 758 int ret = io_data->req->status ? io_data->req->status : 759 io_data->req->actual; 760 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD; 761 762 if (io_data->read && ret > 0) { 763 use_mm(io_data->mm); 764 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); 765 unuse_mm(io_data->mm); 766 } 767 768 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret); 769 770 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd) 771 eventfd_signal(io_data->ffs->ffs_eventfd, 1); 772 773 usb_ep_free_request(io_data->ep, io_data->req); 774 775 if (io_data->read) 776 kfree(io_data->to_free); 777 kfree(io_data->buf); 778 kfree(io_data); 779 } 780 781 static void ffs_epfile_async_io_complete(struct usb_ep *_ep, 782 struct usb_request *req) 783 { 784 struct ffs_io_data *io_data = req->context; 785 786 ENTER(); 787 788 INIT_WORK(&io_data->work, ffs_user_copy_worker); 789 schedule_work(&io_data->work); 790 } 791 792 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile) 793 { 794 /* 795 * See comment in struct ffs_epfile for full read_buffer pointer 796 * synchronisation story. 797 */ 798 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP); 799 if (buf && buf != READ_BUFFER_DROP) 800 kfree(buf); 801 } 802 803 /* Assumes epfile->mutex is held. */ 804 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile, 805 struct iov_iter *iter) 806 { 807 /* 808 * Null out epfile->read_buffer so ffs_func_eps_disable does not free 809 * the buffer while we are using it. See comment in struct ffs_epfile 810 * for full read_buffer pointer synchronisation story. 811 */ 812 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL); 813 ssize_t ret; 814 if (!buf || buf == READ_BUFFER_DROP) 815 return 0; 816 817 ret = copy_to_iter(buf->data, buf->length, iter); 818 if (buf->length == ret) { 819 kfree(buf); 820 return ret; 821 } 822 823 if (unlikely(iov_iter_count(iter))) { 824 ret = -EFAULT; 825 } else { 826 buf->length -= ret; 827 buf->data += ret; 828 } 829 830 if (cmpxchg(&epfile->read_buffer, NULL, buf)) 831 kfree(buf); 832 833 return ret; 834 } 835 836 /* Assumes epfile->mutex is held. */ 837 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile, 838 void *data, int data_len, 839 struct iov_iter *iter) 840 { 841 struct ffs_buffer *buf; 842 843 ssize_t ret = copy_to_iter(data, data_len, iter); 844 if (likely(data_len == ret)) 845 return ret; 846 847 if (unlikely(iov_iter_count(iter))) 848 return -EFAULT; 849 850 /* See ffs_copy_to_iter for more context. */ 851 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.", 852 data_len, ret); 853 854 data_len -= ret; 855 buf = kmalloc(sizeof(*buf) + data_len, GFP_KERNEL); 856 if (!buf) 857 return -ENOMEM; 858 buf->length = data_len; 859 buf->data = buf->storage; 860 memcpy(buf->storage, data + ret, data_len); 861 862 /* 863 * At this point read_buffer is NULL or READ_BUFFER_DROP (if 864 * ffs_func_eps_disable has been called in the meanwhile). See comment 865 * in struct ffs_epfile for full read_buffer pointer synchronisation 866 * story. 867 */ 868 if (unlikely(cmpxchg(&epfile->read_buffer, NULL, buf))) 869 kfree(buf); 870 871 return ret; 872 } 873 874 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) 875 { 876 struct ffs_epfile *epfile = file->private_data; 877 struct usb_request *req; 878 struct ffs_ep *ep; 879 char *data = NULL; 880 ssize_t ret, data_len = -EINVAL; 881 int halt; 882 883 /* Are we still active? */ 884 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 885 return -ENODEV; 886 887 /* Wait for endpoint to be enabled */ 888 ep = epfile->ep; 889 if (!ep) { 890 if (file->f_flags & O_NONBLOCK) 891 return -EAGAIN; 892 893 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep)); 894 if (ret) 895 return -EINTR; 896 } 897 898 /* Do we halt? */ 899 halt = (!io_data->read == !epfile->in); 900 if (halt && epfile->isoc) 901 return -EINVAL; 902 903 /* We will be using request and read_buffer */ 904 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK); 905 if (unlikely(ret)) 906 goto error; 907 908 /* Allocate & copy */ 909 if (!halt) { 910 struct usb_gadget *gadget; 911 912 /* 913 * Do we have buffered data from previous partial read? Check 914 * that for synchronous case only because we do not have 915 * facility to ‘wake up’ a pending asynchronous read and push 916 * buffered data to it which we would need to make things behave 917 * consistently. 918 */ 919 if (!io_data->aio && io_data->read) { 920 ret = __ffs_epfile_read_buffered(epfile, &io_data->data); 921 if (ret) 922 goto error_mutex; 923 } 924 925 /* 926 * if we _do_ wait above, the epfile->ffs->gadget might be NULL 927 * before the waiting completes, so do not assign to 'gadget' 928 * earlier 929 */ 930 gadget = epfile->ffs->gadget; 931 932 spin_lock_irq(&epfile->ffs->eps_lock); 933 /* In the meantime, endpoint got disabled or changed. */ 934 if (epfile->ep != ep) { 935 ret = -ESHUTDOWN; 936 goto error_lock; 937 } 938 data_len = iov_iter_count(&io_data->data); 939 /* 940 * Controller may require buffer size to be aligned to 941 * maxpacketsize of an out endpoint. 942 */ 943 if (io_data->read) 944 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len); 945 spin_unlock_irq(&epfile->ffs->eps_lock); 946 947 data = kmalloc(data_len, GFP_KERNEL); 948 if (unlikely(!data)) { 949 ret = -ENOMEM; 950 goto error_mutex; 951 } 952 if (!io_data->read && 953 !copy_from_iter_full(data, data_len, &io_data->data)) { 954 ret = -EFAULT; 955 goto error_mutex; 956 } 957 } 958 959 spin_lock_irq(&epfile->ffs->eps_lock); 960 961 if (epfile->ep != ep) { 962 /* In the meantime, endpoint got disabled or changed. */ 963 ret = -ESHUTDOWN; 964 } else if (halt) { 965 /* Halt */ 966 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep)) 967 usb_ep_set_halt(ep->ep); 968 ret = -EBADMSG; 969 } else if (unlikely(data_len == -EINVAL)) { 970 /* 971 * Sanity Check: even though data_len can't be used 972 * uninitialized at the time I write this comment, some 973 * compilers complain about this situation. 974 * In order to keep the code clean from warnings, data_len is 975 * being initialized to -EINVAL during its declaration, which 976 * means we can't rely on compiler anymore to warn no future 977 * changes won't result in data_len being used uninitialized. 978 * For such reason, we're adding this redundant sanity check 979 * here. 980 */ 981 WARN(1, "%s: data_len == -EINVAL\n", __func__); 982 ret = -EINVAL; 983 } else if (!io_data->aio) { 984 DECLARE_COMPLETION_ONSTACK(done); 985 bool interrupted = false; 986 987 req = ep->req; 988 req->buf = data; 989 req->length = data_len; 990 991 req->context = &done; 992 req->complete = ffs_epfile_io_complete; 993 994 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 995 if (unlikely(ret < 0)) 996 goto error_lock; 997 998 spin_unlock_irq(&epfile->ffs->eps_lock); 999 1000 if (unlikely(wait_for_completion_interruptible(&done))) { 1001 /* 1002 * To avoid race condition with ffs_epfile_io_complete, 1003 * dequeue the request first then check 1004 * status. usb_ep_dequeue API should guarantee no race 1005 * condition with req->complete callback. 1006 */ 1007 usb_ep_dequeue(ep->ep, req); 1008 interrupted = ep->status < 0; 1009 } 1010 1011 if (interrupted) 1012 ret = -EINTR; 1013 else if (io_data->read && ep->status > 0) 1014 ret = __ffs_epfile_read_data(epfile, data, ep->status, 1015 &io_data->data); 1016 else 1017 ret = ep->status; 1018 goto error_mutex; 1019 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_KERNEL))) { 1020 ret = -ENOMEM; 1021 } else { 1022 req->buf = data; 1023 req->length = data_len; 1024 1025 io_data->buf = data; 1026 io_data->ep = ep->ep; 1027 io_data->req = req; 1028 io_data->ffs = epfile->ffs; 1029 1030 req->context = io_data; 1031 req->complete = ffs_epfile_async_io_complete; 1032 1033 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 1034 if (unlikely(ret)) { 1035 usb_ep_free_request(ep->ep, req); 1036 goto error_lock; 1037 } 1038 1039 ret = -EIOCBQUEUED; 1040 /* 1041 * Do not kfree the buffer in this function. It will be freed 1042 * by ffs_user_copy_worker. 1043 */ 1044 data = NULL; 1045 } 1046 1047 error_lock: 1048 spin_unlock_irq(&epfile->ffs->eps_lock); 1049 error_mutex: 1050 mutex_unlock(&epfile->mutex); 1051 error: 1052 kfree(data); 1053 return ret; 1054 } 1055 1056 static int 1057 ffs_epfile_open(struct inode *inode, struct file *file) 1058 { 1059 struct ffs_epfile *epfile = inode->i_private; 1060 1061 ENTER(); 1062 1063 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 1064 return -ENODEV; 1065 1066 file->private_data = epfile; 1067 ffs_data_opened(epfile->ffs); 1068 1069 return 0; 1070 } 1071 1072 static int ffs_aio_cancel(struct kiocb *kiocb) 1073 { 1074 struct ffs_io_data *io_data = kiocb->private; 1075 struct ffs_epfile *epfile = kiocb->ki_filp->private_data; 1076 int value; 1077 1078 ENTER(); 1079 1080 spin_lock_irq(&epfile->ffs->eps_lock); 1081 1082 if (likely(io_data && io_data->ep && io_data->req)) 1083 value = usb_ep_dequeue(io_data->ep, io_data->req); 1084 else 1085 value = -EINVAL; 1086 1087 spin_unlock_irq(&epfile->ffs->eps_lock); 1088 1089 return value; 1090 } 1091 1092 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from) 1093 { 1094 struct ffs_io_data io_data, *p = &io_data; 1095 ssize_t res; 1096 1097 ENTER(); 1098 1099 if (!is_sync_kiocb(kiocb)) { 1100 p = kmalloc(sizeof(io_data), GFP_KERNEL); 1101 if (unlikely(!p)) 1102 return -ENOMEM; 1103 p->aio = true; 1104 } else { 1105 p->aio = false; 1106 } 1107 1108 p->read = false; 1109 p->kiocb = kiocb; 1110 p->data = *from; 1111 p->mm = current->mm; 1112 1113 kiocb->private = p; 1114 1115 if (p->aio) 1116 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 1117 1118 res = ffs_epfile_io(kiocb->ki_filp, p); 1119 if (res == -EIOCBQUEUED) 1120 return res; 1121 if (p->aio) 1122 kfree(p); 1123 else 1124 *from = p->data; 1125 return res; 1126 } 1127 1128 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) 1129 { 1130 struct ffs_io_data io_data, *p = &io_data; 1131 ssize_t res; 1132 1133 ENTER(); 1134 1135 if (!is_sync_kiocb(kiocb)) { 1136 p = kmalloc(sizeof(io_data), GFP_KERNEL); 1137 if (unlikely(!p)) 1138 return -ENOMEM; 1139 p->aio = true; 1140 } else { 1141 p->aio = false; 1142 } 1143 1144 p->read = true; 1145 p->kiocb = kiocb; 1146 if (p->aio) { 1147 p->to_free = dup_iter(&p->data, to, GFP_KERNEL); 1148 if (!p->to_free) { 1149 kfree(p); 1150 return -ENOMEM; 1151 } 1152 } else { 1153 p->data = *to; 1154 p->to_free = NULL; 1155 } 1156 p->mm = current->mm; 1157 1158 kiocb->private = p; 1159 1160 if (p->aio) 1161 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 1162 1163 res = ffs_epfile_io(kiocb->ki_filp, p); 1164 if (res == -EIOCBQUEUED) 1165 return res; 1166 1167 if (p->aio) { 1168 kfree(p->to_free); 1169 kfree(p); 1170 } else { 1171 *to = p->data; 1172 } 1173 return res; 1174 } 1175 1176 static int 1177 ffs_epfile_release(struct inode *inode, struct file *file) 1178 { 1179 struct ffs_epfile *epfile = inode->i_private; 1180 1181 ENTER(); 1182 1183 __ffs_epfile_read_buffer_free(epfile); 1184 ffs_data_closed(epfile->ffs); 1185 1186 return 0; 1187 } 1188 1189 static long ffs_epfile_ioctl(struct file *file, unsigned code, 1190 unsigned long value) 1191 { 1192 struct ffs_epfile *epfile = file->private_data; 1193 int ret; 1194 1195 ENTER(); 1196 1197 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 1198 return -ENODEV; 1199 1200 spin_lock_irq(&epfile->ffs->eps_lock); 1201 if (likely(epfile->ep)) { 1202 switch (code) { 1203 case FUNCTIONFS_FIFO_STATUS: 1204 ret = usb_ep_fifo_status(epfile->ep->ep); 1205 break; 1206 case FUNCTIONFS_FIFO_FLUSH: 1207 usb_ep_fifo_flush(epfile->ep->ep); 1208 ret = 0; 1209 break; 1210 case FUNCTIONFS_CLEAR_HALT: 1211 ret = usb_ep_clear_halt(epfile->ep->ep); 1212 break; 1213 case FUNCTIONFS_ENDPOINT_REVMAP: 1214 ret = epfile->ep->num; 1215 break; 1216 case FUNCTIONFS_ENDPOINT_DESC: 1217 { 1218 int desc_idx; 1219 struct usb_endpoint_descriptor *desc; 1220 1221 switch (epfile->ffs->gadget->speed) { 1222 case USB_SPEED_SUPER: 1223 desc_idx = 2; 1224 break; 1225 case USB_SPEED_HIGH: 1226 desc_idx = 1; 1227 break; 1228 default: 1229 desc_idx = 0; 1230 } 1231 desc = epfile->ep->descs[desc_idx]; 1232 1233 spin_unlock_irq(&epfile->ffs->eps_lock); 1234 ret = copy_to_user((void *)value, desc, desc->bLength); 1235 if (ret) 1236 ret = -EFAULT; 1237 return ret; 1238 } 1239 default: 1240 ret = -ENOTTY; 1241 } 1242 } else { 1243 ret = -ENODEV; 1244 } 1245 spin_unlock_irq(&epfile->ffs->eps_lock); 1246 1247 return ret; 1248 } 1249 1250 static const struct file_operations ffs_epfile_operations = { 1251 .llseek = no_llseek, 1252 1253 .open = ffs_epfile_open, 1254 .write_iter = ffs_epfile_write_iter, 1255 .read_iter = ffs_epfile_read_iter, 1256 .release = ffs_epfile_release, 1257 .unlocked_ioctl = ffs_epfile_ioctl, 1258 }; 1259 1260 1261 /* File system and super block operations ***********************************/ 1262 1263 /* 1264 * Mounting the file system creates a controller file, used first for 1265 * function configuration then later for event monitoring. 1266 */ 1267 1268 static struct inode *__must_check 1269 ffs_sb_make_inode(struct super_block *sb, void *data, 1270 const struct file_operations *fops, 1271 const struct inode_operations *iops, 1272 struct ffs_file_perms *perms) 1273 { 1274 struct inode *inode; 1275 1276 ENTER(); 1277 1278 inode = new_inode(sb); 1279 1280 if (likely(inode)) { 1281 struct timespec ts = current_time(inode); 1282 1283 inode->i_ino = get_next_ino(); 1284 inode->i_mode = perms->mode; 1285 inode->i_uid = perms->uid; 1286 inode->i_gid = perms->gid; 1287 inode->i_atime = ts; 1288 inode->i_mtime = ts; 1289 inode->i_ctime = ts; 1290 inode->i_private = data; 1291 if (fops) 1292 inode->i_fop = fops; 1293 if (iops) 1294 inode->i_op = iops; 1295 } 1296 1297 return inode; 1298 } 1299 1300 /* Create "regular" file */ 1301 static struct dentry *ffs_sb_create_file(struct super_block *sb, 1302 const char *name, void *data, 1303 const struct file_operations *fops) 1304 { 1305 struct ffs_data *ffs = sb->s_fs_info; 1306 struct dentry *dentry; 1307 struct inode *inode; 1308 1309 ENTER(); 1310 1311 dentry = d_alloc_name(sb->s_root, name); 1312 if (unlikely(!dentry)) 1313 return NULL; 1314 1315 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms); 1316 if (unlikely(!inode)) { 1317 dput(dentry); 1318 return NULL; 1319 } 1320 1321 d_add(dentry, inode); 1322 return dentry; 1323 } 1324 1325 /* Super block */ 1326 static const struct super_operations ffs_sb_operations = { 1327 .statfs = simple_statfs, 1328 .drop_inode = generic_delete_inode, 1329 }; 1330 1331 struct ffs_sb_fill_data { 1332 struct ffs_file_perms perms; 1333 umode_t root_mode; 1334 const char *dev_name; 1335 bool no_disconnect; 1336 struct ffs_data *ffs_data; 1337 }; 1338 1339 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent) 1340 { 1341 struct ffs_sb_fill_data *data = _data; 1342 struct inode *inode; 1343 struct ffs_data *ffs = data->ffs_data; 1344 1345 ENTER(); 1346 1347 ffs->sb = sb; 1348 data->ffs_data = NULL; 1349 sb->s_fs_info = ffs; 1350 sb->s_blocksize = PAGE_SIZE; 1351 sb->s_blocksize_bits = PAGE_SHIFT; 1352 sb->s_magic = FUNCTIONFS_MAGIC; 1353 sb->s_op = &ffs_sb_operations; 1354 sb->s_time_gran = 1; 1355 1356 /* Root inode */ 1357 data->perms.mode = data->root_mode; 1358 inode = ffs_sb_make_inode(sb, NULL, 1359 &simple_dir_operations, 1360 &simple_dir_inode_operations, 1361 &data->perms); 1362 sb->s_root = d_make_root(inode); 1363 if (unlikely(!sb->s_root)) 1364 return -ENOMEM; 1365 1366 /* EP0 file */ 1367 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs, 1368 &ffs_ep0_operations))) 1369 return -ENOMEM; 1370 1371 return 0; 1372 } 1373 1374 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts) 1375 { 1376 ENTER(); 1377 1378 if (!opts || !*opts) 1379 return 0; 1380 1381 for (;;) { 1382 unsigned long value; 1383 char *eq, *comma; 1384 1385 /* Option limit */ 1386 comma = strchr(opts, ','); 1387 if (comma) 1388 *comma = 0; 1389 1390 /* Value limit */ 1391 eq = strchr(opts, '='); 1392 if (unlikely(!eq)) { 1393 pr_err("'=' missing in %s\n", opts); 1394 return -EINVAL; 1395 } 1396 *eq = 0; 1397 1398 /* Parse value */ 1399 if (kstrtoul(eq + 1, 0, &value)) { 1400 pr_err("%s: invalid value: %s\n", opts, eq + 1); 1401 return -EINVAL; 1402 } 1403 1404 /* Interpret option */ 1405 switch (eq - opts) { 1406 case 13: 1407 if (!memcmp(opts, "no_disconnect", 13)) 1408 data->no_disconnect = !!value; 1409 else 1410 goto invalid; 1411 break; 1412 case 5: 1413 if (!memcmp(opts, "rmode", 5)) 1414 data->root_mode = (value & 0555) | S_IFDIR; 1415 else if (!memcmp(opts, "fmode", 5)) 1416 data->perms.mode = (value & 0666) | S_IFREG; 1417 else 1418 goto invalid; 1419 break; 1420 1421 case 4: 1422 if (!memcmp(opts, "mode", 4)) { 1423 data->root_mode = (value & 0555) | S_IFDIR; 1424 data->perms.mode = (value & 0666) | S_IFREG; 1425 } else { 1426 goto invalid; 1427 } 1428 break; 1429 1430 case 3: 1431 if (!memcmp(opts, "uid", 3)) { 1432 data->perms.uid = make_kuid(current_user_ns(), value); 1433 if (!uid_valid(data->perms.uid)) { 1434 pr_err("%s: unmapped value: %lu\n", opts, value); 1435 return -EINVAL; 1436 } 1437 } else if (!memcmp(opts, "gid", 3)) { 1438 data->perms.gid = make_kgid(current_user_ns(), value); 1439 if (!gid_valid(data->perms.gid)) { 1440 pr_err("%s: unmapped value: %lu\n", opts, value); 1441 return -EINVAL; 1442 } 1443 } else { 1444 goto invalid; 1445 } 1446 break; 1447 1448 default: 1449 invalid: 1450 pr_err("%s: invalid option\n", opts); 1451 return -EINVAL; 1452 } 1453 1454 /* Next iteration */ 1455 if (!comma) 1456 break; 1457 opts = comma + 1; 1458 } 1459 1460 return 0; 1461 } 1462 1463 /* "mount -t functionfs dev_name /dev/function" ends up here */ 1464 1465 static struct dentry * 1466 ffs_fs_mount(struct file_system_type *t, int flags, 1467 const char *dev_name, void *opts) 1468 { 1469 struct ffs_sb_fill_data data = { 1470 .perms = { 1471 .mode = S_IFREG | 0600, 1472 .uid = GLOBAL_ROOT_UID, 1473 .gid = GLOBAL_ROOT_GID, 1474 }, 1475 .root_mode = S_IFDIR | 0500, 1476 .no_disconnect = false, 1477 }; 1478 struct dentry *rv; 1479 int ret; 1480 void *ffs_dev; 1481 struct ffs_data *ffs; 1482 1483 ENTER(); 1484 1485 ret = ffs_fs_parse_opts(&data, opts); 1486 if (unlikely(ret < 0)) 1487 return ERR_PTR(ret); 1488 1489 ffs = ffs_data_new(); 1490 if (unlikely(!ffs)) 1491 return ERR_PTR(-ENOMEM); 1492 ffs->file_perms = data.perms; 1493 ffs->no_disconnect = data.no_disconnect; 1494 1495 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL); 1496 if (unlikely(!ffs->dev_name)) { 1497 ffs_data_put(ffs); 1498 return ERR_PTR(-ENOMEM); 1499 } 1500 1501 ffs_dev = ffs_acquire_dev(dev_name); 1502 if (IS_ERR(ffs_dev)) { 1503 ffs_data_put(ffs); 1504 return ERR_CAST(ffs_dev); 1505 } 1506 ffs->private_data = ffs_dev; 1507 data.ffs_data = ffs; 1508 1509 rv = mount_nodev(t, flags, &data, ffs_sb_fill); 1510 if (IS_ERR(rv) && data.ffs_data) { 1511 ffs_release_dev(data.ffs_data); 1512 ffs_data_put(data.ffs_data); 1513 } 1514 return rv; 1515 } 1516 1517 static void 1518 ffs_fs_kill_sb(struct super_block *sb) 1519 { 1520 ENTER(); 1521 1522 kill_litter_super(sb); 1523 if (sb->s_fs_info) { 1524 ffs_release_dev(sb->s_fs_info); 1525 ffs_data_closed(sb->s_fs_info); 1526 ffs_data_put(sb->s_fs_info); 1527 } 1528 } 1529 1530 static struct file_system_type ffs_fs_type = { 1531 .owner = THIS_MODULE, 1532 .name = "functionfs", 1533 .mount = ffs_fs_mount, 1534 .kill_sb = ffs_fs_kill_sb, 1535 }; 1536 MODULE_ALIAS_FS("functionfs"); 1537 1538 1539 /* Driver's main init/cleanup functions *************************************/ 1540 1541 static int functionfs_init(void) 1542 { 1543 int ret; 1544 1545 ENTER(); 1546 1547 ret = register_filesystem(&ffs_fs_type); 1548 if (likely(!ret)) 1549 pr_info("file system registered\n"); 1550 else 1551 pr_err("failed registering file system (%d)\n", ret); 1552 1553 return ret; 1554 } 1555 1556 static void functionfs_cleanup(void) 1557 { 1558 ENTER(); 1559 1560 pr_info("unloading\n"); 1561 unregister_filesystem(&ffs_fs_type); 1562 } 1563 1564 1565 /* ffs_data and ffs_function construction and destruction code **************/ 1566 1567 static void ffs_data_clear(struct ffs_data *ffs); 1568 static void ffs_data_reset(struct ffs_data *ffs); 1569 1570 static void ffs_data_get(struct ffs_data *ffs) 1571 { 1572 ENTER(); 1573 1574 atomic_inc(&ffs->ref); 1575 } 1576 1577 static void ffs_data_opened(struct ffs_data *ffs) 1578 { 1579 ENTER(); 1580 1581 atomic_inc(&ffs->ref); 1582 if (atomic_add_return(1, &ffs->opened) == 1 && 1583 ffs->state == FFS_DEACTIVATED) { 1584 ffs->state = FFS_CLOSING; 1585 ffs_data_reset(ffs); 1586 } 1587 } 1588 1589 static void ffs_data_put(struct ffs_data *ffs) 1590 { 1591 ENTER(); 1592 1593 if (unlikely(atomic_dec_and_test(&ffs->ref))) { 1594 pr_info("%s(): freeing\n", __func__); 1595 ffs_data_clear(ffs); 1596 BUG_ON(waitqueue_active(&ffs->ev.waitq) || 1597 waitqueue_active(&ffs->ep0req_completion.wait)); 1598 kfree(ffs->dev_name); 1599 kfree(ffs); 1600 } 1601 } 1602 1603 static void ffs_data_closed(struct ffs_data *ffs) 1604 { 1605 ENTER(); 1606 1607 if (atomic_dec_and_test(&ffs->opened)) { 1608 if (ffs->no_disconnect) { 1609 ffs->state = FFS_DEACTIVATED; 1610 if (ffs->epfiles) { 1611 ffs_epfiles_destroy(ffs->epfiles, 1612 ffs->eps_count); 1613 ffs->epfiles = NULL; 1614 } 1615 if (ffs->setup_state == FFS_SETUP_PENDING) 1616 __ffs_ep0_stall(ffs); 1617 } else { 1618 ffs->state = FFS_CLOSING; 1619 ffs_data_reset(ffs); 1620 } 1621 } 1622 if (atomic_read(&ffs->opened) < 0) { 1623 ffs->state = FFS_CLOSING; 1624 ffs_data_reset(ffs); 1625 } 1626 1627 ffs_data_put(ffs); 1628 } 1629 1630 static struct ffs_data *ffs_data_new(void) 1631 { 1632 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL); 1633 if (unlikely(!ffs)) 1634 return NULL; 1635 1636 ENTER(); 1637 1638 atomic_set(&ffs->ref, 1); 1639 atomic_set(&ffs->opened, 0); 1640 ffs->state = FFS_READ_DESCRIPTORS; 1641 mutex_init(&ffs->mutex); 1642 spin_lock_init(&ffs->eps_lock); 1643 init_waitqueue_head(&ffs->ev.waitq); 1644 init_completion(&ffs->ep0req_completion); 1645 1646 /* XXX REVISIT need to update it in some places, or do we? */ 1647 ffs->ev.can_stall = 1; 1648 1649 return ffs; 1650 } 1651 1652 static void ffs_data_clear(struct ffs_data *ffs) 1653 { 1654 ENTER(); 1655 1656 ffs_closed(ffs); 1657 1658 BUG_ON(ffs->gadget); 1659 1660 if (ffs->epfiles) 1661 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count); 1662 1663 if (ffs->ffs_eventfd) 1664 eventfd_ctx_put(ffs->ffs_eventfd); 1665 1666 kfree(ffs->raw_descs_data); 1667 kfree(ffs->raw_strings); 1668 kfree(ffs->stringtabs); 1669 } 1670 1671 static void ffs_data_reset(struct ffs_data *ffs) 1672 { 1673 ENTER(); 1674 1675 ffs_data_clear(ffs); 1676 1677 ffs->epfiles = NULL; 1678 ffs->raw_descs_data = NULL; 1679 ffs->raw_descs = NULL; 1680 ffs->raw_strings = NULL; 1681 ffs->stringtabs = NULL; 1682 1683 ffs->raw_descs_length = 0; 1684 ffs->fs_descs_count = 0; 1685 ffs->hs_descs_count = 0; 1686 ffs->ss_descs_count = 0; 1687 1688 ffs->strings_count = 0; 1689 ffs->interfaces_count = 0; 1690 ffs->eps_count = 0; 1691 1692 ffs->ev.count = 0; 1693 1694 ffs->state = FFS_READ_DESCRIPTORS; 1695 ffs->setup_state = FFS_NO_SETUP; 1696 ffs->flags = 0; 1697 } 1698 1699 1700 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) 1701 { 1702 struct usb_gadget_strings **lang; 1703 int first_id; 1704 1705 ENTER(); 1706 1707 if (WARN_ON(ffs->state != FFS_ACTIVE 1708 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags))) 1709 return -EBADFD; 1710 1711 first_id = usb_string_ids_n(cdev, ffs->strings_count); 1712 if (unlikely(first_id < 0)) 1713 return first_id; 1714 1715 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); 1716 if (unlikely(!ffs->ep0req)) 1717 return -ENOMEM; 1718 ffs->ep0req->complete = ffs_ep0_complete; 1719 ffs->ep0req->context = ffs; 1720 1721 lang = ffs->stringtabs; 1722 if (lang) { 1723 for (; *lang; ++lang) { 1724 struct usb_string *str = (*lang)->strings; 1725 int id = first_id; 1726 for (; str->s; ++id, ++str) 1727 str->id = id; 1728 } 1729 } 1730 1731 ffs->gadget = cdev->gadget; 1732 ffs_data_get(ffs); 1733 return 0; 1734 } 1735 1736 static void functionfs_unbind(struct ffs_data *ffs) 1737 { 1738 ENTER(); 1739 1740 if (!WARN_ON(!ffs->gadget)) { 1741 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req); 1742 ffs->ep0req = NULL; 1743 ffs->gadget = NULL; 1744 clear_bit(FFS_FL_BOUND, &ffs->flags); 1745 ffs_data_put(ffs); 1746 } 1747 } 1748 1749 static int ffs_epfiles_create(struct ffs_data *ffs) 1750 { 1751 struct ffs_epfile *epfile, *epfiles; 1752 unsigned i, count; 1753 1754 ENTER(); 1755 1756 count = ffs->eps_count; 1757 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL); 1758 if (!epfiles) 1759 return -ENOMEM; 1760 1761 epfile = epfiles; 1762 for (i = 1; i <= count; ++i, ++epfile) { 1763 epfile->ffs = ffs; 1764 mutex_init(&epfile->mutex); 1765 init_waitqueue_head(&epfile->wait); 1766 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 1767 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]); 1768 else 1769 sprintf(epfile->name, "ep%u", i); 1770 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name, 1771 epfile, 1772 &ffs_epfile_operations); 1773 if (unlikely(!epfile->dentry)) { 1774 ffs_epfiles_destroy(epfiles, i - 1); 1775 return -ENOMEM; 1776 } 1777 } 1778 1779 ffs->epfiles = epfiles; 1780 return 0; 1781 } 1782 1783 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count) 1784 { 1785 struct ffs_epfile *epfile = epfiles; 1786 1787 ENTER(); 1788 1789 for (; count; --count, ++epfile) { 1790 BUG_ON(mutex_is_locked(&epfile->mutex) || 1791 waitqueue_active(&epfile->wait)); 1792 if (epfile->dentry) { 1793 d_delete(epfile->dentry); 1794 dput(epfile->dentry); 1795 epfile->dentry = NULL; 1796 } 1797 } 1798 1799 kfree(epfiles); 1800 } 1801 1802 static void ffs_func_eps_disable(struct ffs_function *func) 1803 { 1804 struct ffs_ep *ep = func->eps; 1805 struct ffs_epfile *epfile = func->ffs->epfiles; 1806 unsigned count = func->ffs->eps_count; 1807 unsigned long flags; 1808 1809 spin_lock_irqsave(&func->ffs->eps_lock, flags); 1810 while (count--) { 1811 /* pending requests get nuked */ 1812 if (likely(ep->ep)) 1813 usb_ep_disable(ep->ep); 1814 ++ep; 1815 1816 if (epfile) { 1817 epfile->ep = NULL; 1818 __ffs_epfile_read_buffer_free(epfile); 1819 ++epfile; 1820 } 1821 } 1822 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 1823 } 1824 1825 static int ffs_func_eps_enable(struct ffs_function *func) 1826 { 1827 struct ffs_data *ffs = func->ffs; 1828 struct ffs_ep *ep = func->eps; 1829 struct ffs_epfile *epfile = ffs->epfiles; 1830 unsigned count = ffs->eps_count; 1831 unsigned long flags; 1832 int ret = 0; 1833 1834 spin_lock_irqsave(&func->ffs->eps_lock, flags); 1835 while(count--) { 1836 struct usb_endpoint_descriptor *ds; 1837 struct usb_ss_ep_comp_descriptor *comp_desc = NULL; 1838 int needs_comp_desc = false; 1839 int desc_idx; 1840 1841 if (ffs->gadget->speed == USB_SPEED_SUPER) { 1842 desc_idx = 2; 1843 needs_comp_desc = true; 1844 } else if (ffs->gadget->speed == USB_SPEED_HIGH) 1845 desc_idx = 1; 1846 else 1847 desc_idx = 0; 1848 1849 /* fall-back to lower speed if desc missing for current speed */ 1850 do { 1851 ds = ep->descs[desc_idx]; 1852 } while (!ds && --desc_idx >= 0); 1853 1854 if (!ds) { 1855 ret = -EINVAL; 1856 break; 1857 } 1858 1859 ep->ep->driver_data = ep; 1860 ep->ep->desc = ds; 1861 1862 comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds + 1863 USB_DT_ENDPOINT_SIZE); 1864 ep->ep->maxburst = comp_desc->bMaxBurst + 1; 1865 1866 if (needs_comp_desc) 1867 ep->ep->comp_desc = comp_desc; 1868 1869 ret = usb_ep_enable(ep->ep); 1870 if (likely(!ret)) { 1871 epfile->ep = ep; 1872 epfile->in = usb_endpoint_dir_in(ds); 1873 epfile->isoc = usb_endpoint_xfer_isoc(ds); 1874 } else { 1875 break; 1876 } 1877 1878 wake_up(&epfile->wait); 1879 1880 ++ep; 1881 ++epfile; 1882 } 1883 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 1884 1885 return ret; 1886 } 1887 1888 1889 /* Parsing and building descriptors and strings *****************************/ 1890 1891 /* 1892 * This validates if data pointed by data is a valid USB descriptor as 1893 * well as record how many interfaces, endpoints and strings are 1894 * required by given configuration. Returns address after the 1895 * descriptor or NULL if data is invalid. 1896 */ 1897 1898 enum ffs_entity_type { 1899 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT 1900 }; 1901 1902 enum ffs_os_desc_type { 1903 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP 1904 }; 1905 1906 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity, 1907 u8 *valuep, 1908 struct usb_descriptor_header *desc, 1909 void *priv); 1910 1911 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity, 1912 struct usb_os_desc_header *h, void *data, 1913 unsigned len, void *priv); 1914 1915 static int __must_check ffs_do_single_desc(char *data, unsigned len, 1916 ffs_entity_callback entity, 1917 void *priv) 1918 { 1919 struct usb_descriptor_header *_ds = (void *)data; 1920 u8 length; 1921 int ret; 1922 1923 ENTER(); 1924 1925 /* At least two bytes are required: length and type */ 1926 if (len < 2) { 1927 pr_vdebug("descriptor too short\n"); 1928 return -EINVAL; 1929 } 1930 1931 /* If we have at least as many bytes as the descriptor takes? */ 1932 length = _ds->bLength; 1933 if (len < length) { 1934 pr_vdebug("descriptor longer then available data\n"); 1935 return -EINVAL; 1936 } 1937 1938 #define __entity_check_INTERFACE(val) 1 1939 #define __entity_check_STRING(val) (val) 1940 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK) 1941 #define __entity(type, val) do { \ 1942 pr_vdebug("entity " #type "(%02x)\n", (val)); \ 1943 if (unlikely(!__entity_check_ ##type(val))) { \ 1944 pr_vdebug("invalid entity's value\n"); \ 1945 return -EINVAL; \ 1946 } \ 1947 ret = entity(FFS_ ##type, &val, _ds, priv); \ 1948 if (unlikely(ret < 0)) { \ 1949 pr_debug("entity " #type "(%02x); ret = %d\n", \ 1950 (val), ret); \ 1951 return ret; \ 1952 } \ 1953 } while (0) 1954 1955 /* Parse descriptor depending on type. */ 1956 switch (_ds->bDescriptorType) { 1957 case USB_DT_DEVICE: 1958 case USB_DT_CONFIG: 1959 case USB_DT_STRING: 1960 case USB_DT_DEVICE_QUALIFIER: 1961 /* function can't have any of those */ 1962 pr_vdebug("descriptor reserved for gadget: %d\n", 1963 _ds->bDescriptorType); 1964 return -EINVAL; 1965 1966 case USB_DT_INTERFACE: { 1967 struct usb_interface_descriptor *ds = (void *)_ds; 1968 pr_vdebug("interface descriptor\n"); 1969 if (length != sizeof *ds) 1970 goto inv_length; 1971 1972 __entity(INTERFACE, ds->bInterfaceNumber); 1973 if (ds->iInterface) 1974 __entity(STRING, ds->iInterface); 1975 } 1976 break; 1977 1978 case USB_DT_ENDPOINT: { 1979 struct usb_endpoint_descriptor *ds = (void *)_ds; 1980 pr_vdebug("endpoint descriptor\n"); 1981 if (length != USB_DT_ENDPOINT_SIZE && 1982 length != USB_DT_ENDPOINT_AUDIO_SIZE) 1983 goto inv_length; 1984 __entity(ENDPOINT, ds->bEndpointAddress); 1985 } 1986 break; 1987 1988 case HID_DT_HID: 1989 pr_vdebug("hid descriptor\n"); 1990 if (length != sizeof(struct hid_descriptor)) 1991 goto inv_length; 1992 break; 1993 1994 case USB_DT_OTG: 1995 if (length != sizeof(struct usb_otg_descriptor)) 1996 goto inv_length; 1997 break; 1998 1999 case USB_DT_INTERFACE_ASSOCIATION: { 2000 struct usb_interface_assoc_descriptor *ds = (void *)_ds; 2001 pr_vdebug("interface association descriptor\n"); 2002 if (length != sizeof *ds) 2003 goto inv_length; 2004 if (ds->iFunction) 2005 __entity(STRING, ds->iFunction); 2006 } 2007 break; 2008 2009 case USB_DT_SS_ENDPOINT_COMP: 2010 pr_vdebug("EP SS companion descriptor\n"); 2011 if (length != sizeof(struct usb_ss_ep_comp_descriptor)) 2012 goto inv_length; 2013 break; 2014 2015 case USB_DT_OTHER_SPEED_CONFIG: 2016 case USB_DT_INTERFACE_POWER: 2017 case USB_DT_DEBUG: 2018 case USB_DT_SECURITY: 2019 case USB_DT_CS_RADIO_CONTROL: 2020 /* TODO */ 2021 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType); 2022 return -EINVAL; 2023 2024 default: 2025 /* We should never be here */ 2026 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType); 2027 return -EINVAL; 2028 2029 inv_length: 2030 pr_vdebug("invalid length: %d (descriptor %d)\n", 2031 _ds->bLength, _ds->bDescriptorType); 2032 return -EINVAL; 2033 } 2034 2035 #undef __entity 2036 #undef __entity_check_DESCRIPTOR 2037 #undef __entity_check_INTERFACE 2038 #undef __entity_check_STRING 2039 #undef __entity_check_ENDPOINT 2040 2041 return length; 2042 } 2043 2044 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, 2045 ffs_entity_callback entity, void *priv) 2046 { 2047 const unsigned _len = len; 2048 unsigned long num = 0; 2049 2050 ENTER(); 2051 2052 for (;;) { 2053 int ret; 2054 2055 if (num == count) 2056 data = NULL; 2057 2058 /* Record "descriptor" entity */ 2059 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv); 2060 if (unlikely(ret < 0)) { 2061 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n", 2062 num, ret); 2063 return ret; 2064 } 2065 2066 if (!data) 2067 return _len - len; 2068 2069 ret = ffs_do_single_desc(data, len, entity, priv); 2070 if (unlikely(ret < 0)) { 2071 pr_debug("%s returns %d\n", __func__, ret); 2072 return ret; 2073 } 2074 2075 len -= ret; 2076 data += ret; 2077 ++num; 2078 } 2079 } 2080 2081 static int __ffs_data_do_entity(enum ffs_entity_type type, 2082 u8 *valuep, struct usb_descriptor_header *desc, 2083 void *priv) 2084 { 2085 struct ffs_desc_helper *helper = priv; 2086 struct usb_endpoint_descriptor *d; 2087 2088 ENTER(); 2089 2090 switch (type) { 2091 case FFS_DESCRIPTOR: 2092 break; 2093 2094 case FFS_INTERFACE: 2095 /* 2096 * Interfaces are indexed from zero so if we 2097 * encountered interface "n" then there are at least 2098 * "n+1" interfaces. 2099 */ 2100 if (*valuep >= helper->interfaces_count) 2101 helper->interfaces_count = *valuep + 1; 2102 break; 2103 2104 case FFS_STRING: 2105 /* 2106 * Strings are indexed from 1 (0 is reserved 2107 * for languages list) 2108 */ 2109 if (*valuep > helper->ffs->strings_count) 2110 helper->ffs->strings_count = *valuep; 2111 break; 2112 2113 case FFS_ENDPOINT: 2114 d = (void *)desc; 2115 helper->eps_count++; 2116 if (helper->eps_count >= FFS_MAX_EPS_COUNT) 2117 return -EINVAL; 2118 /* Check if descriptors for any speed were already parsed */ 2119 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count) 2120 helper->ffs->eps_addrmap[helper->eps_count] = 2121 d->bEndpointAddress; 2122 else if (helper->ffs->eps_addrmap[helper->eps_count] != 2123 d->bEndpointAddress) 2124 return -EINVAL; 2125 break; 2126 } 2127 2128 return 0; 2129 } 2130 2131 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type, 2132 struct usb_os_desc_header *desc) 2133 { 2134 u16 bcd_version = le16_to_cpu(desc->bcdVersion); 2135 u16 w_index = le16_to_cpu(desc->wIndex); 2136 2137 if (bcd_version != 1) { 2138 pr_vdebug("unsupported os descriptors version: %d", 2139 bcd_version); 2140 return -EINVAL; 2141 } 2142 switch (w_index) { 2143 case 0x4: 2144 *next_type = FFS_OS_DESC_EXT_COMPAT; 2145 break; 2146 case 0x5: 2147 *next_type = FFS_OS_DESC_EXT_PROP; 2148 break; 2149 default: 2150 pr_vdebug("unsupported os descriptor type: %d", w_index); 2151 return -EINVAL; 2152 } 2153 2154 return sizeof(*desc); 2155 } 2156 2157 /* 2158 * Process all extended compatibility/extended property descriptors 2159 * of a feature descriptor 2160 */ 2161 static int __must_check ffs_do_single_os_desc(char *data, unsigned len, 2162 enum ffs_os_desc_type type, 2163 u16 feature_count, 2164 ffs_os_desc_callback entity, 2165 void *priv, 2166 struct usb_os_desc_header *h) 2167 { 2168 int ret; 2169 const unsigned _len = len; 2170 2171 ENTER(); 2172 2173 /* loop over all ext compat/ext prop descriptors */ 2174 while (feature_count--) { 2175 ret = entity(type, h, data, len, priv); 2176 if (unlikely(ret < 0)) { 2177 pr_debug("bad OS descriptor, type: %d\n", type); 2178 return ret; 2179 } 2180 data += ret; 2181 len -= ret; 2182 } 2183 return _len - len; 2184 } 2185 2186 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */ 2187 static int __must_check ffs_do_os_descs(unsigned count, 2188 char *data, unsigned len, 2189 ffs_os_desc_callback entity, void *priv) 2190 { 2191 const unsigned _len = len; 2192 unsigned long num = 0; 2193 2194 ENTER(); 2195 2196 for (num = 0; num < count; ++num) { 2197 int ret; 2198 enum ffs_os_desc_type type; 2199 u16 feature_count; 2200 struct usb_os_desc_header *desc = (void *)data; 2201 2202 if (len < sizeof(*desc)) 2203 return -EINVAL; 2204 2205 /* 2206 * Record "descriptor" entity. 2207 * Process dwLength, bcdVersion, wIndex, get b/wCount. 2208 * Move the data pointer to the beginning of extended 2209 * compatibilities proper or extended properties proper 2210 * portions of the data 2211 */ 2212 if (le32_to_cpu(desc->dwLength) > len) 2213 return -EINVAL; 2214 2215 ret = __ffs_do_os_desc_header(&type, desc); 2216 if (unlikely(ret < 0)) { 2217 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n", 2218 num, ret); 2219 return ret; 2220 } 2221 /* 2222 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??" 2223 */ 2224 feature_count = le16_to_cpu(desc->wCount); 2225 if (type == FFS_OS_DESC_EXT_COMPAT && 2226 (feature_count > 255 || desc->Reserved)) 2227 return -EINVAL; 2228 len -= ret; 2229 data += ret; 2230 2231 /* 2232 * Process all function/property descriptors 2233 * of this Feature Descriptor 2234 */ 2235 ret = ffs_do_single_os_desc(data, len, type, 2236 feature_count, entity, priv, desc); 2237 if (unlikely(ret < 0)) { 2238 pr_debug("%s returns %d\n", __func__, ret); 2239 return ret; 2240 } 2241 2242 len -= ret; 2243 data += ret; 2244 } 2245 return _len - len; 2246 } 2247 2248 /** 2249 * Validate contents of the buffer from userspace related to OS descriptors. 2250 */ 2251 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type, 2252 struct usb_os_desc_header *h, void *data, 2253 unsigned len, void *priv) 2254 { 2255 struct ffs_data *ffs = priv; 2256 u8 length; 2257 2258 ENTER(); 2259 2260 switch (type) { 2261 case FFS_OS_DESC_EXT_COMPAT: { 2262 struct usb_ext_compat_desc *d = data; 2263 int i; 2264 2265 if (len < sizeof(*d) || 2266 d->bFirstInterfaceNumber >= ffs->interfaces_count || 2267 !d->Reserved1) 2268 return -EINVAL; 2269 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i) 2270 if (d->Reserved2[i]) 2271 return -EINVAL; 2272 2273 length = sizeof(struct usb_ext_compat_desc); 2274 } 2275 break; 2276 case FFS_OS_DESC_EXT_PROP: { 2277 struct usb_ext_prop_desc *d = data; 2278 u32 type, pdl; 2279 u16 pnl; 2280 2281 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count) 2282 return -EINVAL; 2283 length = le32_to_cpu(d->dwSize); 2284 if (len < length) 2285 return -EINVAL; 2286 type = le32_to_cpu(d->dwPropertyDataType); 2287 if (type < USB_EXT_PROP_UNICODE || 2288 type > USB_EXT_PROP_UNICODE_MULTI) { 2289 pr_vdebug("unsupported os descriptor property type: %d", 2290 type); 2291 return -EINVAL; 2292 } 2293 pnl = le16_to_cpu(d->wPropertyNameLength); 2294 if (length < 14 + pnl) { 2295 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n", 2296 length, pnl, type); 2297 return -EINVAL; 2298 } 2299 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl)); 2300 if (length != 14 + pnl + pdl) { 2301 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n", 2302 length, pnl, pdl, type); 2303 return -EINVAL; 2304 } 2305 ++ffs->ms_os_descs_ext_prop_count; 2306 /* property name reported to the host as "WCHAR"s */ 2307 ffs->ms_os_descs_ext_prop_name_len += pnl * 2; 2308 ffs->ms_os_descs_ext_prop_data_len += pdl; 2309 } 2310 break; 2311 default: 2312 pr_vdebug("unknown descriptor: %d\n", type); 2313 return -EINVAL; 2314 } 2315 return length; 2316 } 2317 2318 static int __ffs_data_got_descs(struct ffs_data *ffs, 2319 char *const _data, size_t len) 2320 { 2321 char *data = _data, *raw_descs; 2322 unsigned os_descs_count = 0, counts[3], flags; 2323 int ret = -EINVAL, i; 2324 struct ffs_desc_helper helper; 2325 2326 ENTER(); 2327 2328 if (get_unaligned_le32(data + 4) != len) 2329 goto error; 2330 2331 switch (get_unaligned_le32(data)) { 2332 case FUNCTIONFS_DESCRIPTORS_MAGIC: 2333 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC; 2334 data += 8; 2335 len -= 8; 2336 break; 2337 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2: 2338 flags = get_unaligned_le32(data + 8); 2339 ffs->user_flags = flags; 2340 if (flags & ~(FUNCTIONFS_HAS_FS_DESC | 2341 FUNCTIONFS_HAS_HS_DESC | 2342 FUNCTIONFS_HAS_SS_DESC | 2343 FUNCTIONFS_HAS_MS_OS_DESC | 2344 FUNCTIONFS_VIRTUAL_ADDR | 2345 FUNCTIONFS_EVENTFD | 2346 FUNCTIONFS_ALL_CTRL_RECIP | 2347 FUNCTIONFS_CONFIG0_SETUP)) { 2348 ret = -ENOSYS; 2349 goto error; 2350 } 2351 data += 12; 2352 len -= 12; 2353 break; 2354 default: 2355 goto error; 2356 } 2357 2358 if (flags & FUNCTIONFS_EVENTFD) { 2359 if (len < 4) 2360 goto error; 2361 ffs->ffs_eventfd = 2362 eventfd_ctx_fdget((int)get_unaligned_le32(data)); 2363 if (IS_ERR(ffs->ffs_eventfd)) { 2364 ret = PTR_ERR(ffs->ffs_eventfd); 2365 ffs->ffs_eventfd = NULL; 2366 goto error; 2367 } 2368 data += 4; 2369 len -= 4; 2370 } 2371 2372 /* Read fs_count, hs_count and ss_count (if present) */ 2373 for (i = 0; i < 3; ++i) { 2374 if (!(flags & (1 << i))) { 2375 counts[i] = 0; 2376 } else if (len < 4) { 2377 goto error; 2378 } else { 2379 counts[i] = get_unaligned_le32(data); 2380 data += 4; 2381 len -= 4; 2382 } 2383 } 2384 if (flags & (1 << i)) { 2385 if (len < 4) { 2386 goto error; 2387 } 2388 os_descs_count = get_unaligned_le32(data); 2389 data += 4; 2390 len -= 4; 2391 }; 2392 2393 /* Read descriptors */ 2394 raw_descs = data; 2395 helper.ffs = ffs; 2396 for (i = 0; i < 3; ++i) { 2397 if (!counts[i]) 2398 continue; 2399 helper.interfaces_count = 0; 2400 helper.eps_count = 0; 2401 ret = ffs_do_descs(counts[i], data, len, 2402 __ffs_data_do_entity, &helper); 2403 if (ret < 0) 2404 goto error; 2405 if (!ffs->eps_count && !ffs->interfaces_count) { 2406 ffs->eps_count = helper.eps_count; 2407 ffs->interfaces_count = helper.interfaces_count; 2408 } else { 2409 if (ffs->eps_count != helper.eps_count) { 2410 ret = -EINVAL; 2411 goto error; 2412 } 2413 if (ffs->interfaces_count != helper.interfaces_count) { 2414 ret = -EINVAL; 2415 goto error; 2416 } 2417 } 2418 data += ret; 2419 len -= ret; 2420 } 2421 if (os_descs_count) { 2422 ret = ffs_do_os_descs(os_descs_count, data, len, 2423 __ffs_data_do_os_desc, ffs); 2424 if (ret < 0) 2425 goto error; 2426 data += ret; 2427 len -= ret; 2428 } 2429 2430 if (raw_descs == data || len) { 2431 ret = -EINVAL; 2432 goto error; 2433 } 2434 2435 ffs->raw_descs_data = _data; 2436 ffs->raw_descs = raw_descs; 2437 ffs->raw_descs_length = data - raw_descs; 2438 ffs->fs_descs_count = counts[0]; 2439 ffs->hs_descs_count = counts[1]; 2440 ffs->ss_descs_count = counts[2]; 2441 ffs->ms_os_descs_count = os_descs_count; 2442 2443 return 0; 2444 2445 error: 2446 kfree(_data); 2447 return ret; 2448 } 2449 2450 static int __ffs_data_got_strings(struct ffs_data *ffs, 2451 char *const _data, size_t len) 2452 { 2453 u32 str_count, needed_count, lang_count; 2454 struct usb_gadget_strings **stringtabs, *t; 2455 const char *data = _data; 2456 struct usb_string *s; 2457 2458 ENTER(); 2459 2460 if (unlikely(len < 16 || 2461 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC || 2462 get_unaligned_le32(data + 4) != len)) 2463 goto error; 2464 str_count = get_unaligned_le32(data + 8); 2465 lang_count = get_unaligned_le32(data + 12); 2466 2467 /* if one is zero the other must be zero */ 2468 if (unlikely(!str_count != !lang_count)) 2469 goto error; 2470 2471 /* Do we have at least as many strings as descriptors need? */ 2472 needed_count = ffs->strings_count; 2473 if (unlikely(str_count < needed_count)) 2474 goto error; 2475 2476 /* 2477 * If we don't need any strings just return and free all 2478 * memory. 2479 */ 2480 if (!needed_count) { 2481 kfree(_data); 2482 return 0; 2483 } 2484 2485 /* Allocate everything in one chunk so there's less maintenance. */ 2486 { 2487 unsigned i = 0; 2488 vla_group(d); 2489 vla_item(d, struct usb_gadget_strings *, stringtabs, 2490 lang_count + 1); 2491 vla_item(d, struct usb_gadget_strings, stringtab, lang_count); 2492 vla_item(d, struct usb_string, strings, 2493 lang_count*(needed_count+1)); 2494 2495 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL); 2496 2497 if (unlikely(!vlabuf)) { 2498 kfree(_data); 2499 return -ENOMEM; 2500 } 2501 2502 /* Initialize the VLA pointers */ 2503 stringtabs = vla_ptr(vlabuf, d, stringtabs); 2504 t = vla_ptr(vlabuf, d, stringtab); 2505 i = lang_count; 2506 do { 2507 *stringtabs++ = t++; 2508 } while (--i); 2509 *stringtabs = NULL; 2510 2511 /* stringtabs = vlabuf = d_stringtabs for later kfree */ 2512 stringtabs = vla_ptr(vlabuf, d, stringtabs); 2513 t = vla_ptr(vlabuf, d, stringtab); 2514 s = vla_ptr(vlabuf, d, strings); 2515 } 2516 2517 /* For each language */ 2518 data += 16; 2519 len -= 16; 2520 2521 do { /* lang_count > 0 so we can use do-while */ 2522 unsigned needed = needed_count; 2523 2524 if (unlikely(len < 3)) 2525 goto error_free; 2526 t->language = get_unaligned_le16(data); 2527 t->strings = s; 2528 ++t; 2529 2530 data += 2; 2531 len -= 2; 2532 2533 /* For each string */ 2534 do { /* str_count > 0 so we can use do-while */ 2535 size_t length = strnlen(data, len); 2536 2537 if (unlikely(length == len)) 2538 goto error_free; 2539 2540 /* 2541 * User may provide more strings then we need, 2542 * if that's the case we simply ignore the 2543 * rest 2544 */ 2545 if (likely(needed)) { 2546 /* 2547 * s->id will be set while adding 2548 * function to configuration so for 2549 * now just leave garbage here. 2550 */ 2551 s->s = data; 2552 --needed; 2553 ++s; 2554 } 2555 2556 data += length + 1; 2557 len -= length + 1; 2558 } while (--str_count); 2559 2560 s->id = 0; /* terminator */ 2561 s->s = NULL; 2562 ++s; 2563 2564 } while (--lang_count); 2565 2566 /* Some garbage left? */ 2567 if (unlikely(len)) 2568 goto error_free; 2569 2570 /* Done! */ 2571 ffs->stringtabs = stringtabs; 2572 ffs->raw_strings = _data; 2573 2574 return 0; 2575 2576 error_free: 2577 kfree(stringtabs); 2578 error: 2579 kfree(_data); 2580 return -EINVAL; 2581 } 2582 2583 2584 /* Events handling and management *******************************************/ 2585 2586 static void __ffs_event_add(struct ffs_data *ffs, 2587 enum usb_functionfs_event_type type) 2588 { 2589 enum usb_functionfs_event_type rem_type1, rem_type2 = type; 2590 int neg = 0; 2591 2592 /* 2593 * Abort any unhandled setup 2594 * 2595 * We do not need to worry about some cmpxchg() changing value 2596 * of ffs->setup_state without holding the lock because when 2597 * state is FFS_SETUP_PENDING cmpxchg() in several places in 2598 * the source does nothing. 2599 */ 2600 if (ffs->setup_state == FFS_SETUP_PENDING) 2601 ffs->setup_state = FFS_SETUP_CANCELLED; 2602 2603 /* 2604 * Logic of this function guarantees that there are at most four pending 2605 * evens on ffs->ev.types queue. This is important because the queue 2606 * has space for four elements only and __ffs_ep0_read_events function 2607 * depends on that limit as well. If more event types are added, those 2608 * limits have to be revisited or guaranteed to still hold. 2609 */ 2610 switch (type) { 2611 case FUNCTIONFS_RESUME: 2612 rem_type2 = FUNCTIONFS_SUSPEND; 2613 /* FALL THROUGH */ 2614 case FUNCTIONFS_SUSPEND: 2615 case FUNCTIONFS_SETUP: 2616 rem_type1 = type; 2617 /* Discard all similar events */ 2618 break; 2619 2620 case FUNCTIONFS_BIND: 2621 case FUNCTIONFS_UNBIND: 2622 case FUNCTIONFS_DISABLE: 2623 case FUNCTIONFS_ENABLE: 2624 /* Discard everything other then power management. */ 2625 rem_type1 = FUNCTIONFS_SUSPEND; 2626 rem_type2 = FUNCTIONFS_RESUME; 2627 neg = 1; 2628 break; 2629 2630 default: 2631 WARN(1, "%d: unknown event, this should not happen\n", type); 2632 return; 2633 } 2634 2635 { 2636 u8 *ev = ffs->ev.types, *out = ev; 2637 unsigned n = ffs->ev.count; 2638 for (; n; --n, ++ev) 2639 if ((*ev == rem_type1 || *ev == rem_type2) == neg) 2640 *out++ = *ev; 2641 else 2642 pr_vdebug("purging event %d\n", *ev); 2643 ffs->ev.count = out - ffs->ev.types; 2644 } 2645 2646 pr_vdebug("adding event %d\n", type); 2647 ffs->ev.types[ffs->ev.count++] = type; 2648 wake_up_locked(&ffs->ev.waitq); 2649 if (ffs->ffs_eventfd) 2650 eventfd_signal(ffs->ffs_eventfd, 1); 2651 } 2652 2653 static void ffs_event_add(struct ffs_data *ffs, 2654 enum usb_functionfs_event_type type) 2655 { 2656 unsigned long flags; 2657 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 2658 __ffs_event_add(ffs, type); 2659 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 2660 } 2661 2662 /* Bind/unbind USB function hooks *******************************************/ 2663 2664 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address) 2665 { 2666 int i; 2667 2668 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i) 2669 if (ffs->eps_addrmap[i] == endpoint_address) 2670 return i; 2671 return -ENOENT; 2672 } 2673 2674 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep, 2675 struct usb_descriptor_header *desc, 2676 void *priv) 2677 { 2678 struct usb_endpoint_descriptor *ds = (void *)desc; 2679 struct ffs_function *func = priv; 2680 struct ffs_ep *ffs_ep; 2681 unsigned ep_desc_id; 2682 int idx; 2683 static const char *speed_names[] = { "full", "high", "super" }; 2684 2685 if (type != FFS_DESCRIPTOR) 2686 return 0; 2687 2688 /* 2689 * If ss_descriptors is not NULL, we are reading super speed 2690 * descriptors; if hs_descriptors is not NULL, we are reading high 2691 * speed descriptors; otherwise, we are reading full speed 2692 * descriptors. 2693 */ 2694 if (func->function.ss_descriptors) { 2695 ep_desc_id = 2; 2696 func->function.ss_descriptors[(long)valuep] = desc; 2697 } else if (func->function.hs_descriptors) { 2698 ep_desc_id = 1; 2699 func->function.hs_descriptors[(long)valuep] = desc; 2700 } else { 2701 ep_desc_id = 0; 2702 func->function.fs_descriptors[(long)valuep] = desc; 2703 } 2704 2705 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) 2706 return 0; 2707 2708 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1; 2709 if (idx < 0) 2710 return idx; 2711 2712 ffs_ep = func->eps + idx; 2713 2714 if (unlikely(ffs_ep->descs[ep_desc_id])) { 2715 pr_err("two %sspeed descriptors for EP %d\n", 2716 speed_names[ep_desc_id], 2717 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); 2718 return -EINVAL; 2719 } 2720 ffs_ep->descs[ep_desc_id] = ds; 2721 2722 ffs_dump_mem(": Original ep desc", ds, ds->bLength); 2723 if (ffs_ep->ep) { 2724 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress; 2725 if (!ds->wMaxPacketSize) 2726 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize; 2727 } else { 2728 struct usb_request *req; 2729 struct usb_ep *ep; 2730 u8 bEndpointAddress; 2731 2732 /* 2733 * We back up bEndpointAddress because autoconfig overwrites 2734 * it with physical endpoint address. 2735 */ 2736 bEndpointAddress = ds->bEndpointAddress; 2737 pr_vdebug("autoconfig\n"); 2738 ep = usb_ep_autoconfig(func->gadget, ds); 2739 if (unlikely(!ep)) 2740 return -ENOTSUPP; 2741 ep->driver_data = func->eps + idx; 2742 2743 req = usb_ep_alloc_request(ep, GFP_KERNEL); 2744 if (unlikely(!req)) 2745 return -ENOMEM; 2746 2747 ffs_ep->ep = ep; 2748 ffs_ep->req = req; 2749 func->eps_revmap[ds->bEndpointAddress & 2750 USB_ENDPOINT_NUMBER_MASK] = idx + 1; 2751 /* 2752 * If we use virtual address mapping, we restore 2753 * original bEndpointAddress value. 2754 */ 2755 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 2756 ds->bEndpointAddress = bEndpointAddress; 2757 } 2758 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength); 2759 2760 return 0; 2761 } 2762 2763 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep, 2764 struct usb_descriptor_header *desc, 2765 void *priv) 2766 { 2767 struct ffs_function *func = priv; 2768 unsigned idx; 2769 u8 newValue; 2770 2771 switch (type) { 2772 default: 2773 case FFS_DESCRIPTOR: 2774 /* Handled in previous pass by __ffs_func_bind_do_descs() */ 2775 return 0; 2776 2777 case FFS_INTERFACE: 2778 idx = *valuep; 2779 if (func->interfaces_nums[idx] < 0) { 2780 int id = usb_interface_id(func->conf, &func->function); 2781 if (unlikely(id < 0)) 2782 return id; 2783 func->interfaces_nums[idx] = id; 2784 } 2785 newValue = func->interfaces_nums[idx]; 2786 break; 2787 2788 case FFS_STRING: 2789 /* String' IDs are allocated when fsf_data is bound to cdev */ 2790 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id; 2791 break; 2792 2793 case FFS_ENDPOINT: 2794 /* 2795 * USB_DT_ENDPOINT are handled in 2796 * __ffs_func_bind_do_descs(). 2797 */ 2798 if (desc->bDescriptorType == USB_DT_ENDPOINT) 2799 return 0; 2800 2801 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1; 2802 if (unlikely(!func->eps[idx].ep)) 2803 return -EINVAL; 2804 2805 { 2806 struct usb_endpoint_descriptor **descs; 2807 descs = func->eps[idx].descs; 2808 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress; 2809 } 2810 break; 2811 } 2812 2813 pr_vdebug("%02x -> %02x\n", *valuep, newValue); 2814 *valuep = newValue; 2815 return 0; 2816 } 2817 2818 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type, 2819 struct usb_os_desc_header *h, void *data, 2820 unsigned len, void *priv) 2821 { 2822 struct ffs_function *func = priv; 2823 u8 length = 0; 2824 2825 switch (type) { 2826 case FFS_OS_DESC_EXT_COMPAT: { 2827 struct usb_ext_compat_desc *desc = data; 2828 struct usb_os_desc_table *t; 2829 2830 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber]; 2831 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber]; 2832 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID, 2833 ARRAY_SIZE(desc->CompatibleID) + 2834 ARRAY_SIZE(desc->SubCompatibleID)); 2835 length = sizeof(*desc); 2836 } 2837 break; 2838 case FFS_OS_DESC_EXT_PROP: { 2839 struct usb_ext_prop_desc *desc = data; 2840 struct usb_os_desc_table *t; 2841 struct usb_os_desc_ext_prop *ext_prop; 2842 char *ext_prop_name; 2843 char *ext_prop_data; 2844 2845 t = &func->function.os_desc_table[h->interface]; 2846 t->if_id = func->interfaces_nums[h->interface]; 2847 2848 ext_prop = func->ffs->ms_os_descs_ext_prop_avail; 2849 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop); 2850 2851 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType); 2852 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength); 2853 ext_prop->data_len = le32_to_cpu(*(u32 *) 2854 usb_ext_prop_data_len_ptr(data, ext_prop->name_len)); 2855 length = ext_prop->name_len + ext_prop->data_len + 14; 2856 2857 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail; 2858 func->ffs->ms_os_descs_ext_prop_name_avail += 2859 ext_prop->name_len; 2860 2861 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail; 2862 func->ffs->ms_os_descs_ext_prop_data_avail += 2863 ext_prop->data_len; 2864 memcpy(ext_prop_data, 2865 usb_ext_prop_data_ptr(data, ext_prop->name_len), 2866 ext_prop->data_len); 2867 /* unicode data reported to the host as "WCHAR"s */ 2868 switch (ext_prop->type) { 2869 case USB_EXT_PROP_UNICODE: 2870 case USB_EXT_PROP_UNICODE_ENV: 2871 case USB_EXT_PROP_UNICODE_LINK: 2872 case USB_EXT_PROP_UNICODE_MULTI: 2873 ext_prop->data_len *= 2; 2874 break; 2875 } 2876 ext_prop->data = ext_prop_data; 2877 2878 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data), 2879 ext_prop->name_len); 2880 /* property name reported to the host as "WCHAR"s */ 2881 ext_prop->name_len *= 2; 2882 ext_prop->name = ext_prop_name; 2883 2884 t->os_desc->ext_prop_len += 2885 ext_prop->name_len + ext_prop->data_len + 14; 2886 ++t->os_desc->ext_prop_count; 2887 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop); 2888 } 2889 break; 2890 default: 2891 pr_vdebug("unknown descriptor: %d\n", type); 2892 } 2893 2894 return length; 2895 } 2896 2897 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, 2898 struct usb_configuration *c) 2899 { 2900 struct ffs_function *func = ffs_func_from_usb(f); 2901 struct f_fs_opts *ffs_opts = 2902 container_of(f->fi, struct f_fs_opts, func_inst); 2903 int ret; 2904 2905 ENTER(); 2906 2907 /* 2908 * Legacy gadget triggers binding in functionfs_ready_callback, 2909 * which already uses locking; taking the same lock here would 2910 * cause a deadlock. 2911 * 2912 * Configfs-enabled gadgets however do need ffs_dev_lock. 2913 */ 2914 if (!ffs_opts->no_configfs) 2915 ffs_dev_lock(); 2916 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV; 2917 func->ffs = ffs_opts->dev->ffs_data; 2918 if (!ffs_opts->no_configfs) 2919 ffs_dev_unlock(); 2920 if (ret) 2921 return ERR_PTR(ret); 2922 2923 func->conf = c; 2924 func->gadget = c->cdev->gadget; 2925 2926 /* 2927 * in drivers/usb/gadget/configfs.c:configfs_composite_bind() 2928 * configurations are bound in sequence with list_for_each_entry, 2929 * in each configuration its functions are bound in sequence 2930 * with list_for_each_entry, so we assume no race condition 2931 * with regard to ffs_opts->bound access 2932 */ 2933 if (!ffs_opts->refcnt) { 2934 ret = functionfs_bind(func->ffs, c->cdev); 2935 if (ret) 2936 return ERR_PTR(ret); 2937 } 2938 ffs_opts->refcnt++; 2939 func->function.strings = func->ffs->stringtabs; 2940 2941 return ffs_opts; 2942 } 2943 2944 static int _ffs_func_bind(struct usb_configuration *c, 2945 struct usb_function *f) 2946 { 2947 struct ffs_function *func = ffs_func_from_usb(f); 2948 struct ffs_data *ffs = func->ffs; 2949 2950 const int full = !!func->ffs->fs_descs_count; 2951 const int high = gadget_is_dualspeed(func->gadget) && 2952 func->ffs->hs_descs_count; 2953 const int super = gadget_is_superspeed(func->gadget) && 2954 func->ffs->ss_descs_count; 2955 2956 int fs_len, hs_len, ss_len, ret, i; 2957 struct ffs_ep *eps_ptr; 2958 2959 /* Make it a single chunk, less management later on */ 2960 vla_group(d); 2961 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count); 2962 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs, 2963 full ? ffs->fs_descs_count + 1 : 0); 2964 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs, 2965 high ? ffs->hs_descs_count + 1 : 0); 2966 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs, 2967 super ? ffs->ss_descs_count + 1 : 0); 2968 vla_item_with_sz(d, short, inums, ffs->interfaces_count); 2969 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table, 2970 c->cdev->use_os_string ? ffs->interfaces_count : 0); 2971 vla_item_with_sz(d, char[16], ext_compat, 2972 c->cdev->use_os_string ? ffs->interfaces_count : 0); 2973 vla_item_with_sz(d, struct usb_os_desc, os_desc, 2974 c->cdev->use_os_string ? ffs->interfaces_count : 0); 2975 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop, 2976 ffs->ms_os_descs_ext_prop_count); 2977 vla_item_with_sz(d, char, ext_prop_name, 2978 ffs->ms_os_descs_ext_prop_name_len); 2979 vla_item_with_sz(d, char, ext_prop_data, 2980 ffs->ms_os_descs_ext_prop_data_len); 2981 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length); 2982 char *vlabuf; 2983 2984 ENTER(); 2985 2986 /* Has descriptors only for speeds gadget does not support */ 2987 if (unlikely(!(full | high | super))) 2988 return -ENOTSUPP; 2989 2990 /* Allocate a single chunk, less management later on */ 2991 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL); 2992 if (unlikely(!vlabuf)) 2993 return -ENOMEM; 2994 2995 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop); 2996 ffs->ms_os_descs_ext_prop_name_avail = 2997 vla_ptr(vlabuf, d, ext_prop_name); 2998 ffs->ms_os_descs_ext_prop_data_avail = 2999 vla_ptr(vlabuf, d, ext_prop_data); 3000 3001 /* Copy descriptors */ 3002 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs, 3003 ffs->raw_descs_length); 3004 3005 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz); 3006 eps_ptr = vla_ptr(vlabuf, d, eps); 3007 for (i = 0; i < ffs->eps_count; i++) 3008 eps_ptr[i].num = -1; 3009 3010 /* Save pointers 3011 * d_eps == vlabuf, func->eps used to kfree vlabuf later 3012 */ 3013 func->eps = vla_ptr(vlabuf, d, eps); 3014 func->interfaces_nums = vla_ptr(vlabuf, d, inums); 3015 3016 /* 3017 * Go through all the endpoint descriptors and allocate 3018 * endpoints first, so that later we can rewrite the endpoint 3019 * numbers without worrying that it may be described later on. 3020 */ 3021 if (likely(full)) { 3022 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs); 3023 fs_len = ffs_do_descs(ffs->fs_descs_count, 3024 vla_ptr(vlabuf, d, raw_descs), 3025 d_raw_descs__sz, 3026 __ffs_func_bind_do_descs, func); 3027 if (unlikely(fs_len < 0)) { 3028 ret = fs_len; 3029 goto error; 3030 } 3031 } else { 3032 fs_len = 0; 3033 } 3034 3035 if (likely(high)) { 3036 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs); 3037 hs_len = ffs_do_descs(ffs->hs_descs_count, 3038 vla_ptr(vlabuf, d, raw_descs) + fs_len, 3039 d_raw_descs__sz - fs_len, 3040 __ffs_func_bind_do_descs, func); 3041 if (unlikely(hs_len < 0)) { 3042 ret = hs_len; 3043 goto error; 3044 } 3045 } else { 3046 hs_len = 0; 3047 } 3048 3049 if (likely(super)) { 3050 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs); 3051 ss_len = ffs_do_descs(ffs->ss_descs_count, 3052 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len, 3053 d_raw_descs__sz - fs_len - hs_len, 3054 __ffs_func_bind_do_descs, func); 3055 if (unlikely(ss_len < 0)) { 3056 ret = ss_len; 3057 goto error; 3058 } 3059 } else { 3060 ss_len = 0; 3061 } 3062 3063 /* 3064 * Now handle interface numbers allocation and interface and 3065 * endpoint numbers rewriting. We can do that in one go 3066 * now. 3067 */ 3068 ret = ffs_do_descs(ffs->fs_descs_count + 3069 (high ? ffs->hs_descs_count : 0) + 3070 (super ? ffs->ss_descs_count : 0), 3071 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz, 3072 __ffs_func_bind_do_nums, func); 3073 if (unlikely(ret < 0)) 3074 goto error; 3075 3076 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table); 3077 if (c->cdev->use_os_string) { 3078 for (i = 0; i < ffs->interfaces_count; ++i) { 3079 struct usb_os_desc *desc; 3080 3081 desc = func->function.os_desc_table[i].os_desc = 3082 vla_ptr(vlabuf, d, os_desc) + 3083 i * sizeof(struct usb_os_desc); 3084 desc->ext_compat_id = 3085 vla_ptr(vlabuf, d, ext_compat) + i * 16; 3086 INIT_LIST_HEAD(&desc->ext_prop); 3087 } 3088 ret = ffs_do_os_descs(ffs->ms_os_descs_count, 3089 vla_ptr(vlabuf, d, raw_descs) + 3090 fs_len + hs_len + ss_len, 3091 d_raw_descs__sz - fs_len - hs_len - 3092 ss_len, 3093 __ffs_func_bind_do_os_desc, func); 3094 if (unlikely(ret < 0)) 3095 goto error; 3096 } 3097 func->function.os_desc_n = 3098 c->cdev->use_os_string ? ffs->interfaces_count : 0; 3099 3100 /* And we're done */ 3101 ffs_event_add(ffs, FUNCTIONFS_BIND); 3102 return 0; 3103 3104 error: 3105 /* XXX Do we need to release all claimed endpoints here? */ 3106 return ret; 3107 } 3108 3109 static int ffs_func_bind(struct usb_configuration *c, 3110 struct usb_function *f) 3111 { 3112 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c); 3113 struct ffs_function *func = ffs_func_from_usb(f); 3114 int ret; 3115 3116 if (IS_ERR(ffs_opts)) 3117 return PTR_ERR(ffs_opts); 3118 3119 ret = _ffs_func_bind(c, f); 3120 if (ret && !--ffs_opts->refcnt) 3121 functionfs_unbind(func->ffs); 3122 3123 return ret; 3124 } 3125 3126 3127 /* Other USB function hooks *************************************************/ 3128 3129 static void ffs_reset_work(struct work_struct *work) 3130 { 3131 struct ffs_data *ffs = container_of(work, 3132 struct ffs_data, reset_work); 3133 ffs_data_reset(ffs); 3134 } 3135 3136 static int ffs_func_set_alt(struct usb_function *f, 3137 unsigned interface, unsigned alt) 3138 { 3139 struct ffs_function *func = ffs_func_from_usb(f); 3140 struct ffs_data *ffs = func->ffs; 3141 int ret = 0, intf; 3142 3143 if (alt != (unsigned)-1) { 3144 intf = ffs_func_revmap_intf(func, interface); 3145 if (unlikely(intf < 0)) 3146 return intf; 3147 } 3148 3149 if (ffs->func) 3150 ffs_func_eps_disable(ffs->func); 3151 3152 if (ffs->state == FFS_DEACTIVATED) { 3153 ffs->state = FFS_CLOSING; 3154 INIT_WORK(&ffs->reset_work, ffs_reset_work); 3155 schedule_work(&ffs->reset_work); 3156 return -ENODEV; 3157 } 3158 3159 if (ffs->state != FFS_ACTIVE) 3160 return -ENODEV; 3161 3162 if (alt == (unsigned)-1) { 3163 ffs->func = NULL; 3164 ffs_event_add(ffs, FUNCTIONFS_DISABLE); 3165 return 0; 3166 } 3167 3168 ffs->func = func; 3169 ret = ffs_func_eps_enable(func); 3170 if (likely(ret >= 0)) 3171 ffs_event_add(ffs, FUNCTIONFS_ENABLE); 3172 return ret; 3173 } 3174 3175 static void ffs_func_disable(struct usb_function *f) 3176 { 3177 ffs_func_set_alt(f, 0, (unsigned)-1); 3178 } 3179 3180 static int ffs_func_setup(struct usb_function *f, 3181 const struct usb_ctrlrequest *creq) 3182 { 3183 struct ffs_function *func = ffs_func_from_usb(f); 3184 struct ffs_data *ffs = func->ffs; 3185 unsigned long flags; 3186 int ret; 3187 3188 ENTER(); 3189 3190 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType); 3191 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest); 3192 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue)); 3193 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex)); 3194 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength)); 3195 3196 /* 3197 * Most requests directed to interface go through here 3198 * (notable exceptions are set/get interface) so we need to 3199 * handle them. All other either handled by composite or 3200 * passed to usb_configuration->setup() (if one is set). No 3201 * matter, we will handle requests directed to endpoint here 3202 * as well (as it's straightforward). Other request recipient 3203 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP 3204 * is being used. 3205 */ 3206 if (ffs->state != FFS_ACTIVE) 3207 return -ENODEV; 3208 3209 switch (creq->bRequestType & USB_RECIP_MASK) { 3210 case USB_RECIP_INTERFACE: 3211 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex)); 3212 if (unlikely(ret < 0)) 3213 return ret; 3214 break; 3215 3216 case USB_RECIP_ENDPOINT: 3217 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex)); 3218 if (unlikely(ret < 0)) 3219 return ret; 3220 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 3221 ret = func->ffs->eps_addrmap[ret]; 3222 break; 3223 3224 default: 3225 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP) 3226 ret = le16_to_cpu(creq->wIndex); 3227 else 3228 return -EOPNOTSUPP; 3229 } 3230 3231 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 3232 ffs->ev.setup = *creq; 3233 ffs->ev.setup.wIndex = cpu_to_le16(ret); 3234 __ffs_event_add(ffs, FUNCTIONFS_SETUP); 3235 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 3236 3237 return 0; 3238 } 3239 3240 static bool ffs_func_req_match(struct usb_function *f, 3241 const struct usb_ctrlrequest *creq, 3242 bool config0) 3243 { 3244 struct ffs_function *func = ffs_func_from_usb(f); 3245 3246 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP)) 3247 return false; 3248 3249 switch (creq->bRequestType & USB_RECIP_MASK) { 3250 case USB_RECIP_INTERFACE: 3251 return (ffs_func_revmap_intf(func, 3252 le16_to_cpu(creq->wIndex)) >= 0); 3253 case USB_RECIP_ENDPOINT: 3254 return (ffs_func_revmap_ep(func, 3255 le16_to_cpu(creq->wIndex)) >= 0); 3256 default: 3257 return (bool) (func->ffs->user_flags & 3258 FUNCTIONFS_ALL_CTRL_RECIP); 3259 } 3260 } 3261 3262 static void ffs_func_suspend(struct usb_function *f) 3263 { 3264 ENTER(); 3265 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND); 3266 } 3267 3268 static void ffs_func_resume(struct usb_function *f) 3269 { 3270 ENTER(); 3271 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME); 3272 } 3273 3274 3275 /* Endpoint and interface numbers reverse mapping ***************************/ 3276 3277 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) 3278 { 3279 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK]; 3280 return num ? num : -EDOM; 3281 } 3282 3283 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) 3284 { 3285 short *nums = func->interfaces_nums; 3286 unsigned count = func->ffs->interfaces_count; 3287 3288 for (; count; --count, ++nums) { 3289 if (*nums >= 0 && *nums == intf) 3290 return nums - func->interfaces_nums; 3291 } 3292 3293 return -EDOM; 3294 } 3295 3296 3297 /* Devices management *******************************************************/ 3298 3299 static LIST_HEAD(ffs_devices); 3300 3301 static struct ffs_dev *_ffs_do_find_dev(const char *name) 3302 { 3303 struct ffs_dev *dev; 3304 3305 list_for_each_entry(dev, &ffs_devices, entry) { 3306 if (!dev->name || !name) 3307 continue; 3308 if (strcmp(dev->name, name) == 0) 3309 return dev; 3310 } 3311 3312 return NULL; 3313 } 3314 3315 /* 3316 * ffs_lock must be taken by the caller of this function 3317 */ 3318 static struct ffs_dev *_ffs_get_single_dev(void) 3319 { 3320 struct ffs_dev *dev; 3321 3322 if (list_is_singular(&ffs_devices)) { 3323 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry); 3324 if (dev->single) 3325 return dev; 3326 } 3327 3328 return NULL; 3329 } 3330 3331 /* 3332 * ffs_lock must be taken by the caller of this function 3333 */ 3334 static struct ffs_dev *_ffs_find_dev(const char *name) 3335 { 3336 struct ffs_dev *dev; 3337 3338 dev = _ffs_get_single_dev(); 3339 if (dev) 3340 return dev; 3341 3342 return _ffs_do_find_dev(name); 3343 } 3344 3345 /* Configfs support *********************************************************/ 3346 3347 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item) 3348 { 3349 return container_of(to_config_group(item), struct f_fs_opts, 3350 func_inst.group); 3351 } 3352 3353 static void ffs_attr_release(struct config_item *item) 3354 { 3355 struct f_fs_opts *opts = to_ffs_opts(item); 3356 3357 usb_put_function_instance(&opts->func_inst); 3358 } 3359 3360 static struct configfs_item_operations ffs_item_ops = { 3361 .release = ffs_attr_release, 3362 }; 3363 3364 static struct config_item_type ffs_func_type = { 3365 .ct_item_ops = &ffs_item_ops, 3366 .ct_owner = THIS_MODULE, 3367 }; 3368 3369 3370 /* Function registration interface ******************************************/ 3371 3372 static void ffs_free_inst(struct usb_function_instance *f) 3373 { 3374 struct f_fs_opts *opts; 3375 3376 opts = to_f_fs_opts(f); 3377 ffs_dev_lock(); 3378 _ffs_free_dev(opts->dev); 3379 ffs_dev_unlock(); 3380 kfree(opts); 3381 } 3382 3383 #define MAX_INST_NAME_LEN 40 3384 3385 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name) 3386 { 3387 struct f_fs_opts *opts; 3388 char *ptr; 3389 const char *tmp; 3390 int name_len, ret; 3391 3392 name_len = strlen(name) + 1; 3393 if (name_len > MAX_INST_NAME_LEN) 3394 return -ENAMETOOLONG; 3395 3396 ptr = kstrndup(name, name_len, GFP_KERNEL); 3397 if (!ptr) 3398 return -ENOMEM; 3399 3400 opts = to_f_fs_opts(fi); 3401 tmp = NULL; 3402 3403 ffs_dev_lock(); 3404 3405 tmp = opts->dev->name_allocated ? opts->dev->name : NULL; 3406 ret = _ffs_name_dev(opts->dev, ptr); 3407 if (ret) { 3408 kfree(ptr); 3409 ffs_dev_unlock(); 3410 return ret; 3411 } 3412 opts->dev->name_allocated = true; 3413 3414 ffs_dev_unlock(); 3415 3416 kfree(tmp); 3417 3418 return 0; 3419 } 3420 3421 static struct usb_function_instance *ffs_alloc_inst(void) 3422 { 3423 struct f_fs_opts *opts; 3424 struct ffs_dev *dev; 3425 3426 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 3427 if (!opts) 3428 return ERR_PTR(-ENOMEM); 3429 3430 opts->func_inst.set_inst_name = ffs_set_inst_name; 3431 opts->func_inst.free_func_inst = ffs_free_inst; 3432 ffs_dev_lock(); 3433 dev = _ffs_alloc_dev(); 3434 ffs_dev_unlock(); 3435 if (IS_ERR(dev)) { 3436 kfree(opts); 3437 return ERR_CAST(dev); 3438 } 3439 opts->dev = dev; 3440 dev->opts = opts; 3441 3442 config_group_init_type_name(&opts->func_inst.group, "", 3443 &ffs_func_type); 3444 return &opts->func_inst; 3445 } 3446 3447 static void ffs_free(struct usb_function *f) 3448 { 3449 kfree(ffs_func_from_usb(f)); 3450 } 3451 3452 static void ffs_func_unbind(struct usb_configuration *c, 3453 struct usb_function *f) 3454 { 3455 struct ffs_function *func = ffs_func_from_usb(f); 3456 struct ffs_data *ffs = func->ffs; 3457 struct f_fs_opts *opts = 3458 container_of(f->fi, struct f_fs_opts, func_inst); 3459 struct ffs_ep *ep = func->eps; 3460 unsigned count = ffs->eps_count; 3461 unsigned long flags; 3462 3463 ENTER(); 3464 if (ffs->func == func) { 3465 ffs_func_eps_disable(func); 3466 ffs->func = NULL; 3467 } 3468 3469 if (!--opts->refcnt) 3470 functionfs_unbind(ffs); 3471 3472 /* cleanup after autoconfig */ 3473 spin_lock_irqsave(&func->ffs->eps_lock, flags); 3474 while (count--) { 3475 if (ep->ep && ep->req) 3476 usb_ep_free_request(ep->ep, ep->req); 3477 ep->req = NULL; 3478 ++ep; 3479 } 3480 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 3481 kfree(func->eps); 3482 func->eps = NULL; 3483 /* 3484 * eps, descriptors and interfaces_nums are allocated in the 3485 * same chunk so only one free is required. 3486 */ 3487 func->function.fs_descriptors = NULL; 3488 func->function.hs_descriptors = NULL; 3489 func->function.ss_descriptors = NULL; 3490 func->interfaces_nums = NULL; 3491 3492 ffs_event_add(ffs, FUNCTIONFS_UNBIND); 3493 } 3494 3495 static struct usb_function *ffs_alloc(struct usb_function_instance *fi) 3496 { 3497 struct ffs_function *func; 3498 3499 ENTER(); 3500 3501 func = kzalloc(sizeof(*func), GFP_KERNEL); 3502 if (unlikely(!func)) 3503 return ERR_PTR(-ENOMEM); 3504 3505 func->function.name = "Function FS Gadget"; 3506 3507 func->function.bind = ffs_func_bind; 3508 func->function.unbind = ffs_func_unbind; 3509 func->function.set_alt = ffs_func_set_alt; 3510 func->function.disable = ffs_func_disable; 3511 func->function.setup = ffs_func_setup; 3512 func->function.req_match = ffs_func_req_match; 3513 func->function.suspend = ffs_func_suspend; 3514 func->function.resume = ffs_func_resume; 3515 func->function.free_func = ffs_free; 3516 3517 return &func->function; 3518 } 3519 3520 /* 3521 * ffs_lock must be taken by the caller of this function 3522 */ 3523 static struct ffs_dev *_ffs_alloc_dev(void) 3524 { 3525 struct ffs_dev *dev; 3526 int ret; 3527 3528 if (_ffs_get_single_dev()) 3529 return ERR_PTR(-EBUSY); 3530 3531 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 3532 if (!dev) 3533 return ERR_PTR(-ENOMEM); 3534 3535 if (list_empty(&ffs_devices)) { 3536 ret = functionfs_init(); 3537 if (ret) { 3538 kfree(dev); 3539 return ERR_PTR(ret); 3540 } 3541 } 3542 3543 list_add(&dev->entry, &ffs_devices); 3544 3545 return dev; 3546 } 3547 3548 /* 3549 * ffs_lock must be taken by the caller of this function 3550 * The caller is responsible for "name" being available whenever f_fs needs it 3551 */ 3552 static int _ffs_name_dev(struct ffs_dev *dev, const char *name) 3553 { 3554 struct ffs_dev *existing; 3555 3556 existing = _ffs_do_find_dev(name); 3557 if (existing) 3558 return -EBUSY; 3559 3560 dev->name = name; 3561 3562 return 0; 3563 } 3564 3565 /* 3566 * The caller is responsible for "name" being available whenever f_fs needs it 3567 */ 3568 int ffs_name_dev(struct ffs_dev *dev, const char *name) 3569 { 3570 int ret; 3571 3572 ffs_dev_lock(); 3573 ret = _ffs_name_dev(dev, name); 3574 ffs_dev_unlock(); 3575 3576 return ret; 3577 } 3578 EXPORT_SYMBOL_GPL(ffs_name_dev); 3579 3580 int ffs_single_dev(struct ffs_dev *dev) 3581 { 3582 int ret; 3583 3584 ret = 0; 3585 ffs_dev_lock(); 3586 3587 if (!list_is_singular(&ffs_devices)) 3588 ret = -EBUSY; 3589 else 3590 dev->single = true; 3591 3592 ffs_dev_unlock(); 3593 return ret; 3594 } 3595 EXPORT_SYMBOL_GPL(ffs_single_dev); 3596 3597 /* 3598 * ffs_lock must be taken by the caller of this function 3599 */ 3600 static void _ffs_free_dev(struct ffs_dev *dev) 3601 { 3602 list_del(&dev->entry); 3603 if (dev->name_allocated) 3604 kfree(dev->name); 3605 3606 /* Clear the private_data pointer to stop incorrect dev access */ 3607 if (dev->ffs_data) 3608 dev->ffs_data->private_data = NULL; 3609 3610 kfree(dev); 3611 if (list_empty(&ffs_devices)) 3612 functionfs_cleanup(); 3613 } 3614 3615 static void *ffs_acquire_dev(const char *dev_name) 3616 { 3617 struct ffs_dev *ffs_dev; 3618 3619 ENTER(); 3620 ffs_dev_lock(); 3621 3622 ffs_dev = _ffs_find_dev(dev_name); 3623 if (!ffs_dev) 3624 ffs_dev = ERR_PTR(-ENOENT); 3625 else if (ffs_dev->mounted) 3626 ffs_dev = ERR_PTR(-EBUSY); 3627 else if (ffs_dev->ffs_acquire_dev_callback && 3628 ffs_dev->ffs_acquire_dev_callback(ffs_dev)) 3629 ffs_dev = ERR_PTR(-ENOENT); 3630 else 3631 ffs_dev->mounted = true; 3632 3633 ffs_dev_unlock(); 3634 return ffs_dev; 3635 } 3636 3637 static void ffs_release_dev(struct ffs_data *ffs_data) 3638 { 3639 struct ffs_dev *ffs_dev; 3640 3641 ENTER(); 3642 ffs_dev_lock(); 3643 3644 ffs_dev = ffs_data->private_data; 3645 if (ffs_dev) { 3646 ffs_dev->mounted = false; 3647 3648 if (ffs_dev->ffs_release_dev_callback) 3649 ffs_dev->ffs_release_dev_callback(ffs_dev); 3650 } 3651 3652 ffs_dev_unlock(); 3653 } 3654 3655 static int ffs_ready(struct ffs_data *ffs) 3656 { 3657 struct ffs_dev *ffs_obj; 3658 int ret = 0; 3659 3660 ENTER(); 3661 ffs_dev_lock(); 3662 3663 ffs_obj = ffs->private_data; 3664 if (!ffs_obj) { 3665 ret = -EINVAL; 3666 goto done; 3667 } 3668 if (WARN_ON(ffs_obj->desc_ready)) { 3669 ret = -EBUSY; 3670 goto done; 3671 } 3672 3673 ffs_obj->desc_ready = true; 3674 ffs_obj->ffs_data = ffs; 3675 3676 if (ffs_obj->ffs_ready_callback) { 3677 ret = ffs_obj->ffs_ready_callback(ffs); 3678 if (ret) 3679 goto done; 3680 } 3681 3682 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags); 3683 done: 3684 ffs_dev_unlock(); 3685 return ret; 3686 } 3687 3688 static void ffs_closed(struct ffs_data *ffs) 3689 { 3690 struct ffs_dev *ffs_obj; 3691 struct f_fs_opts *opts; 3692 struct config_item *ci; 3693 3694 ENTER(); 3695 ffs_dev_lock(); 3696 3697 ffs_obj = ffs->private_data; 3698 if (!ffs_obj) 3699 goto done; 3700 3701 ffs_obj->desc_ready = false; 3702 3703 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && 3704 ffs_obj->ffs_closed_callback) 3705 ffs_obj->ffs_closed_callback(ffs); 3706 3707 if (ffs_obj->opts) 3708 opts = ffs_obj->opts; 3709 else 3710 goto done; 3711 3712 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent 3713 || !kref_read(&opts->func_inst.group.cg_item.ci_kref)) 3714 goto done; 3715 3716 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent; 3717 ffs_dev_unlock(); 3718 3719 unregister_gadget_item(ci); 3720 return; 3721 done: 3722 ffs_dev_unlock(); 3723 } 3724 3725 /* Misc helper functions ****************************************************/ 3726 3727 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 3728 { 3729 return nonblock 3730 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN 3731 : mutex_lock_interruptible(mutex); 3732 } 3733 3734 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 3735 { 3736 char *data; 3737 3738 if (unlikely(!len)) 3739 return NULL; 3740 3741 data = kmalloc(len, GFP_KERNEL); 3742 if (unlikely(!data)) 3743 return ERR_PTR(-ENOMEM); 3744 3745 if (unlikely(copy_from_user(data, buf, len))) { 3746 kfree(data); 3747 return ERR_PTR(-EFAULT); 3748 } 3749 3750 pr_vdebug("Buffer from user space:\n"); 3751 ffs_dump_mem("", data, len); 3752 3753 return data; 3754 } 3755 3756 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc); 3757 MODULE_LICENSE("GPL"); 3758 MODULE_AUTHOR("Michal Nazarewicz"); 3759