1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * f_fs.c -- user mode file system API for USB composite function controllers 4 * 5 * Copyright (C) 2010 Samsung Electronics 6 * Author: Michal Nazarewicz <mina86@mina86.com> 7 * 8 * Based on inode.c (GadgetFS) which was: 9 * Copyright (C) 2003-2004 David Brownell 10 * Copyright (C) 2003 Agilent Technologies 11 */ 12 13 14 /* #define DEBUG */ 15 /* #define VERBOSE_DEBUG */ 16 17 #include <linux/blkdev.h> 18 #include <linux/dma-buf.h> 19 #include <linux/dma-fence.h> 20 #include <linux/dma-resv.h> 21 #include <linux/pagemap.h> 22 #include <linux/export.h> 23 #include <linux/fs_parser.h> 24 #include <linux/hid.h> 25 #include <linux/mm.h> 26 #include <linux/module.h> 27 #include <linux/scatterlist.h> 28 #include <linux/sched/signal.h> 29 #include <linux/uio.h> 30 #include <linux/vmalloc.h> 31 #include <linux/unaligned.h> 32 33 #include <linux/usb/ccid.h> 34 #include <linux/usb/composite.h> 35 #include <linux/usb/functionfs.h> 36 #include <linux/usb/func_utils.h> 37 38 #include <linux/aio.h> 39 #include <linux/kthread.h> 40 #include <linux/poll.h> 41 #include <linux/eventfd.h> 42 43 #include "u_fs.h" 44 #include "u_os_desc.h" 45 #include "configfs.h" 46 47 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ 48 #define MAX_ALT_SETTINGS 2 /* Allow up to 2 alt settings to be set. */ 49 50 #define DMABUF_ENQUEUE_TIMEOUT_MS 5000 51 52 MODULE_IMPORT_NS("DMA_BUF"); 53 54 /* Reference counter handling */ 55 static void ffs_data_get(struct ffs_data *ffs); 56 static void ffs_data_put(struct ffs_data *ffs); 57 /* Creates new ffs_data object. */ 58 static struct ffs_data *__must_check ffs_data_new(const char *dev_name) 59 __attribute__((malloc)); 60 61 /* Opened counter handling. */ 62 static void ffs_data_closed(struct ffs_data *ffs); 63 64 /* Called with ffs->mutex held; take over ownership of data. */ 65 static int __must_check 66 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len); 67 static int __must_check 68 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len); 69 70 71 /* The function structure ***************************************************/ 72 73 struct ffs_ep; 74 75 struct ffs_function { 76 struct usb_configuration *conf; 77 struct usb_gadget *gadget; 78 struct ffs_data *ffs; 79 80 struct ffs_ep *eps; 81 u8 eps_revmap[16]; 82 short *interfaces_nums; 83 84 struct usb_function function; 85 int cur_alt[MAX_CONFIG_INTERFACES]; 86 }; 87 88 89 static struct ffs_function *ffs_func_from_usb(struct usb_function *f) 90 { 91 return container_of(f, struct ffs_function, function); 92 } 93 94 95 static inline enum ffs_setup_state 96 ffs_setup_state_clear_cancelled(struct ffs_data *ffs) 97 { 98 return (enum ffs_setup_state) 99 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP); 100 } 101 102 103 static void ffs_func_eps_disable(struct ffs_function *func); 104 static int __must_check ffs_func_eps_enable(struct ffs_function *func); 105 106 static int ffs_func_bind(struct usb_configuration *, 107 struct usb_function *); 108 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned); 109 static int ffs_func_get_alt(struct usb_function *f, unsigned int intf); 110 static void ffs_func_disable(struct usb_function *); 111 static int ffs_func_setup(struct usb_function *, 112 const struct usb_ctrlrequest *); 113 static bool ffs_func_req_match(struct usb_function *, 114 const struct usb_ctrlrequest *, 115 bool config0); 116 static void ffs_func_suspend(struct usb_function *); 117 static void ffs_func_resume(struct usb_function *); 118 119 120 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num); 121 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf); 122 123 124 /* The endpoints structures *************************************************/ 125 126 struct ffs_ep { 127 struct usb_ep *ep; /* P: ffs->eps_lock */ 128 struct usb_request *req; /* P: epfile->mutex */ 129 130 /* [0]: full speed, [1]: high speed, [2]: super speed */ 131 struct usb_endpoint_descriptor *descs[3]; 132 133 u8 num; 134 }; 135 136 struct ffs_dmabuf_priv { 137 struct list_head entry; 138 struct kref ref; 139 struct ffs_data *ffs; 140 struct dma_buf_attachment *attach; 141 struct sg_table *sgt; 142 enum dma_data_direction dir; 143 spinlock_t lock; 144 u64 context; 145 struct usb_request *req; /* P: ffs->eps_lock */ 146 struct usb_ep *ep; /* P: ffs->eps_lock */ 147 }; 148 149 struct ffs_dma_fence { 150 struct dma_fence base; 151 struct ffs_dmabuf_priv *priv; 152 struct work_struct work; 153 }; 154 155 struct ffs_epfile { 156 /* Protects ep->ep and ep->req. */ 157 struct mutex mutex; 158 159 struct ffs_data *ffs; 160 struct ffs_ep *ep; /* P: ffs->eps_lock */ 161 162 /* 163 * Buffer for holding data from partial reads which may happen since 164 * we’re rounding user read requests to a multiple of a max packet size. 165 * 166 * The pointer is initialised with NULL value and may be set by 167 * __ffs_epfile_read_data function to point to a temporary buffer. 168 * 169 * In normal operation, calls to __ffs_epfile_read_buffered will consume 170 * data from said buffer and eventually free it. Importantly, while the 171 * function is using the buffer, it sets the pointer to NULL. This is 172 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered 173 * can never run concurrently (they are synchronised by epfile->mutex) 174 * so the latter will not assign a new value to the pointer. 175 * 176 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is 177 * valid) and sets the pointer to READ_BUFFER_DROP value. This special 178 * value is crux of the synchronisation between ffs_func_eps_disable and 179 * __ffs_epfile_read_data. 180 * 181 * Once __ffs_epfile_read_data is about to finish it will try to set the 182 * pointer back to its old value (as described above), but seeing as the 183 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free 184 * the buffer. 185 * 186 * == State transitions == 187 * 188 * • ptr == NULL: (initial state) 189 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP 190 * ◦ __ffs_epfile_read_buffered: nop 191 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf 192 * ◦ reading finishes: n/a, not in ‘and reading’ state 193 * • ptr == DROP: 194 * ◦ __ffs_epfile_read_buffer_free: nop 195 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL 196 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop 197 * ◦ reading finishes: n/a, not in ‘and reading’ state 198 * • ptr == buf: 199 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP 200 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading 201 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered 202 * is always called first 203 * ◦ reading finishes: n/a, not in ‘and reading’ state 204 * • ptr == NULL and reading: 205 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading 206 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held 207 * ◦ __ffs_epfile_read_data: n/a, mutex is held 208 * ◦ reading finishes and … 209 * … all data read: free buf, go to ptr == NULL 210 * … otherwise: go to ptr == buf and reading 211 * • ptr == DROP and reading: 212 * ◦ __ffs_epfile_read_buffer_free: nop 213 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held 214 * ◦ __ffs_epfile_read_data: n/a, mutex is held 215 * ◦ reading finishes: free buf, go to ptr == DROP 216 */ 217 struct ffs_buffer *read_buffer; 218 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN)) 219 220 char name[5]; 221 222 unsigned char in; /* P: ffs->eps_lock */ 223 unsigned char isoc; /* P: ffs->eps_lock */ 224 225 unsigned char _pad; 226 227 /* Protects dmabufs */ 228 struct mutex dmabufs_mutex; 229 struct list_head dmabufs; /* P: dmabufs_mutex */ 230 atomic_t seqno; 231 }; 232 233 struct ffs_buffer { 234 size_t length; 235 char *data; 236 char storage[] __counted_by(length); 237 }; 238 239 /* ffs_io_data structure ***************************************************/ 240 241 struct ffs_io_data { 242 bool aio; 243 bool read; 244 245 struct kiocb *kiocb; 246 struct iov_iter data; 247 const void *to_free; 248 char *buf; 249 250 struct mm_struct *mm; 251 struct work_struct work; 252 253 struct usb_ep *ep; 254 struct usb_request *req; 255 struct sg_table sgt; 256 bool use_sg; 257 258 struct ffs_data *ffs; 259 260 int status; 261 struct completion done; 262 }; 263 264 struct ffs_desc_helper { 265 struct ffs_data *ffs; 266 unsigned interfaces_count; 267 unsigned eps_count; 268 }; 269 270 static int __must_check ffs_epfiles_create(struct ffs_data *ffs); 271 static void ffs_epfiles_destroy(struct super_block *sb, 272 struct ffs_epfile *epfiles, unsigned count); 273 274 static int ffs_sb_create_file(struct super_block *sb, const char *name, 275 void *data, const struct file_operations *fops); 276 277 /* Devices management *******************************************************/ 278 279 DEFINE_MUTEX(ffs_lock); 280 EXPORT_SYMBOL_GPL(ffs_lock); 281 282 static struct ffs_dev *_ffs_find_dev(const char *name); 283 static struct ffs_dev *_ffs_alloc_dev(void); 284 static void _ffs_free_dev(struct ffs_dev *dev); 285 static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data); 286 static void ffs_release_dev(struct ffs_dev *ffs_dev); 287 static int ffs_ready(struct ffs_data *ffs); 288 static void ffs_closed(struct ffs_data *ffs); 289 290 /* Misc helper functions ****************************************************/ 291 292 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 293 __attribute__((warn_unused_result, nonnull)); 294 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 295 __attribute__((warn_unused_result, nonnull)); 296 297 298 /* Control file aka ep0 *****************************************************/ 299 300 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req) 301 { 302 struct ffs_data *ffs = req->context; 303 304 complete(&ffs->ep0req_completion); 305 } 306 307 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len) 308 __releases(&ffs->ev.waitq.lock) 309 { 310 struct usb_request *req = ffs->ep0req; 311 int ret; 312 313 if (!req) { 314 spin_unlock_irq(&ffs->ev.waitq.lock); 315 return -EINVAL; 316 } 317 318 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength); 319 320 spin_unlock_irq(&ffs->ev.waitq.lock); 321 322 req->buf = data; 323 req->length = len; 324 325 /* 326 * UDC layer requires to provide a buffer even for ZLP, but should 327 * not use it at all. Let's provide some poisoned pointer to catch 328 * possible bug in the driver. 329 */ 330 if (req->buf == NULL) 331 req->buf = (void *)0xDEADBABE; 332 333 reinit_completion(&ffs->ep0req_completion); 334 335 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC); 336 if (ret < 0) 337 return ret; 338 339 ret = wait_for_completion_interruptible(&ffs->ep0req_completion); 340 if (ret) { 341 usb_ep_dequeue(ffs->gadget->ep0, req); 342 return -EINTR; 343 } 344 345 ffs->setup_state = FFS_NO_SETUP; 346 return req->status ? req->status : req->actual; 347 } 348 349 static int __ffs_ep0_stall(struct ffs_data *ffs) 350 { 351 if (ffs->ev.can_stall) { 352 pr_vdebug("ep0 stall\n"); 353 usb_ep_set_halt(ffs->gadget->ep0); 354 ffs->setup_state = FFS_NO_SETUP; 355 return -EL2HLT; 356 } else { 357 pr_debug("bogus ep0 stall!\n"); 358 return -ESRCH; 359 } 360 } 361 362 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, 363 size_t len, loff_t *ptr) 364 { 365 struct ffs_data *ffs = file->private_data; 366 ssize_t ret; 367 char *data; 368 369 /* Fast check if setup was canceled */ 370 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 371 return -EIDRM; 372 373 /* Acquire mutex */ 374 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 375 if (ret < 0) 376 return ret; 377 378 /* Check state */ 379 switch (ffs->state) { 380 case FFS_READ_DESCRIPTORS: 381 case FFS_READ_STRINGS: 382 /* Copy data */ 383 if (len < 16) { 384 ret = -EINVAL; 385 break; 386 } 387 388 data = ffs_prepare_buffer(buf, len); 389 if (IS_ERR(data)) { 390 ret = PTR_ERR(data); 391 break; 392 } 393 394 /* Handle data */ 395 if (ffs->state == FFS_READ_DESCRIPTORS) { 396 pr_info("read descriptors\n"); 397 ret = __ffs_data_got_descs(ffs, data, len); 398 if (ret < 0) 399 break; 400 401 ffs->state = FFS_READ_STRINGS; 402 ret = len; 403 } else { 404 pr_info("read strings\n"); 405 ret = __ffs_data_got_strings(ffs, data, len); 406 if (ret < 0) 407 break; 408 409 ret = ffs_epfiles_create(ffs); 410 if (ret) { 411 ffs->state = FFS_CLOSING; 412 break; 413 } 414 415 ffs->state = FFS_ACTIVE; 416 mutex_unlock(&ffs->mutex); 417 418 ret = ffs_ready(ffs); 419 if (ret < 0) { 420 ffs->state = FFS_CLOSING; 421 return ret; 422 } 423 424 return len; 425 } 426 break; 427 428 case FFS_ACTIVE: 429 data = NULL; 430 /* 431 * We're called from user space, we can use _irq 432 * rather then _irqsave 433 */ 434 spin_lock_irq(&ffs->ev.waitq.lock); 435 switch (ffs_setup_state_clear_cancelled(ffs)) { 436 case FFS_SETUP_CANCELLED: 437 ret = -EIDRM; 438 goto done_spin; 439 440 case FFS_NO_SETUP: 441 ret = -ESRCH; 442 goto done_spin; 443 444 case FFS_SETUP_PENDING: 445 break; 446 } 447 448 /* FFS_SETUP_PENDING */ 449 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) { 450 spin_unlock_irq(&ffs->ev.waitq.lock); 451 ret = __ffs_ep0_stall(ffs); 452 break; 453 } 454 455 /* FFS_SETUP_PENDING and not stall */ 456 len = min_t(size_t, len, le16_to_cpu(ffs->ev.setup.wLength)); 457 458 spin_unlock_irq(&ffs->ev.waitq.lock); 459 460 data = ffs_prepare_buffer(buf, len); 461 if (IS_ERR(data)) { 462 ret = PTR_ERR(data); 463 break; 464 } 465 466 spin_lock_irq(&ffs->ev.waitq.lock); 467 468 /* 469 * We are guaranteed to be still in FFS_ACTIVE state 470 * but the state of setup could have changed from 471 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need 472 * to check for that. If that happened we copied data 473 * from user space in vain but it's unlikely. 474 * 475 * For sure we are not in FFS_NO_SETUP since this is 476 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP 477 * transition can be performed and it's protected by 478 * mutex. 479 */ 480 if (ffs_setup_state_clear_cancelled(ffs) == 481 FFS_SETUP_CANCELLED) { 482 ret = -EIDRM; 483 done_spin: 484 spin_unlock_irq(&ffs->ev.waitq.lock); 485 } else { 486 /* unlocks spinlock */ 487 ret = __ffs_ep0_queue_wait(ffs, data, len); 488 } 489 kfree(data); 490 break; 491 492 default: 493 ret = -EBADFD; 494 break; 495 } 496 497 mutex_unlock(&ffs->mutex); 498 return ret; 499 } 500 501 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */ 502 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf, 503 size_t n) 504 __releases(&ffs->ev.waitq.lock) 505 { 506 /* 507 * n cannot be bigger than ffs->ev.count, which cannot be bigger than 508 * size of ffs->ev.types array (which is four) so that's how much space 509 * we reserve. 510 */ 511 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)]; 512 const size_t size = n * sizeof *events; 513 unsigned i = 0; 514 515 memset(events, 0, size); 516 517 do { 518 events[i].type = ffs->ev.types[i]; 519 if (events[i].type == FUNCTIONFS_SETUP) { 520 events[i].u.setup = ffs->ev.setup; 521 ffs->setup_state = FFS_SETUP_PENDING; 522 } 523 } while (++i < n); 524 525 ffs->ev.count -= n; 526 if (ffs->ev.count) 527 memmove(ffs->ev.types, ffs->ev.types + n, 528 ffs->ev.count * sizeof *ffs->ev.types); 529 530 spin_unlock_irq(&ffs->ev.waitq.lock); 531 mutex_unlock(&ffs->mutex); 532 533 return copy_to_user(buf, events, size) ? -EFAULT : size; 534 } 535 536 static ssize_t ffs_ep0_read(struct file *file, char __user *buf, 537 size_t len, loff_t *ptr) 538 { 539 struct ffs_data *ffs = file->private_data; 540 char *data = NULL; 541 size_t n; 542 int ret; 543 544 /* Fast check if setup was canceled */ 545 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 546 return -EIDRM; 547 548 /* Acquire mutex */ 549 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 550 if (ret < 0) 551 return ret; 552 553 /* Check state */ 554 if (ffs->state != FFS_ACTIVE) { 555 ret = -EBADFD; 556 goto done_mutex; 557 } 558 559 /* 560 * We're called from user space, we can use _irq rather then 561 * _irqsave 562 */ 563 spin_lock_irq(&ffs->ev.waitq.lock); 564 565 switch (ffs_setup_state_clear_cancelled(ffs)) { 566 case FFS_SETUP_CANCELLED: 567 ret = -EIDRM; 568 break; 569 570 case FFS_NO_SETUP: 571 n = len / sizeof(struct usb_functionfs_event); 572 if (!n) { 573 ret = -EINVAL; 574 break; 575 } 576 577 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) { 578 ret = -EAGAIN; 579 break; 580 } 581 582 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, 583 ffs->ev.count)) { 584 ret = -EINTR; 585 break; 586 } 587 588 /* unlocks spinlock */ 589 return __ffs_ep0_read_events(ffs, buf, 590 min_t(size_t, n, ffs->ev.count)); 591 592 case FFS_SETUP_PENDING: 593 if (ffs->ev.setup.bRequestType & USB_DIR_IN) { 594 spin_unlock_irq(&ffs->ev.waitq.lock); 595 ret = __ffs_ep0_stall(ffs); 596 goto done_mutex; 597 } 598 599 len = min_t(size_t, len, le16_to_cpu(ffs->ev.setup.wLength)); 600 601 spin_unlock_irq(&ffs->ev.waitq.lock); 602 603 if (len) { 604 data = kmalloc(len, GFP_KERNEL); 605 if (!data) { 606 ret = -ENOMEM; 607 goto done_mutex; 608 } 609 } 610 611 spin_lock_irq(&ffs->ev.waitq.lock); 612 613 /* See ffs_ep0_write() */ 614 if (ffs_setup_state_clear_cancelled(ffs) == 615 FFS_SETUP_CANCELLED) { 616 ret = -EIDRM; 617 break; 618 } 619 620 /* unlocks spinlock */ 621 ret = __ffs_ep0_queue_wait(ffs, data, len); 622 if ((ret > 0) && (copy_to_user(buf, data, len))) 623 ret = -EFAULT; 624 goto done_mutex; 625 626 default: 627 ret = -EBADFD; 628 break; 629 } 630 631 spin_unlock_irq(&ffs->ev.waitq.lock); 632 done_mutex: 633 mutex_unlock(&ffs->mutex); 634 kfree(data); 635 return ret; 636 } 637 638 639 static void ffs_data_reset(struct ffs_data *ffs); 640 641 static int ffs_ep0_open(struct inode *inode, struct file *file) 642 { 643 struct ffs_data *ffs = inode->i_sb->s_fs_info; 644 645 spin_lock_irq(&ffs->eps_lock); 646 if (ffs->state == FFS_CLOSING) { 647 spin_unlock_irq(&ffs->eps_lock); 648 return -EBUSY; 649 } 650 if (!ffs->opened++ && ffs->state == FFS_DEACTIVATED) { 651 ffs->state = FFS_CLOSING; 652 spin_unlock_irq(&ffs->eps_lock); 653 ffs_data_reset(ffs); 654 } else { 655 spin_unlock_irq(&ffs->eps_lock); 656 } 657 file->private_data = ffs; 658 659 return stream_open(inode, file); 660 } 661 662 static int ffs_ep0_release(struct inode *inode, struct file *file) 663 { 664 struct ffs_data *ffs = file->private_data; 665 666 ffs_data_closed(ffs); 667 668 return 0; 669 } 670 671 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) 672 { 673 struct ffs_data *ffs = file->private_data; 674 struct usb_gadget *gadget = ffs->gadget; 675 long ret; 676 677 if (code == FUNCTIONFS_INTERFACE_REVMAP) { 678 struct ffs_function *func = ffs->func; 679 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV; 680 } else if (gadget && gadget->ops->ioctl) { 681 ret = gadget->ops->ioctl(gadget, code, value); 682 } else { 683 ret = -ENOTTY; 684 } 685 686 return ret; 687 } 688 689 static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait) 690 { 691 struct ffs_data *ffs = file->private_data; 692 __poll_t mask = EPOLLWRNORM; 693 int ret; 694 695 poll_wait(file, &ffs->ev.waitq, wait); 696 697 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 698 if (ret < 0) 699 return mask; 700 701 switch (ffs->state) { 702 case FFS_READ_DESCRIPTORS: 703 case FFS_READ_STRINGS: 704 mask |= EPOLLOUT; 705 break; 706 707 case FFS_ACTIVE: 708 switch (ffs->setup_state) { 709 case FFS_NO_SETUP: 710 if (ffs->ev.count) 711 mask |= EPOLLIN; 712 break; 713 714 case FFS_SETUP_PENDING: 715 case FFS_SETUP_CANCELLED: 716 mask |= (EPOLLIN | EPOLLOUT); 717 break; 718 } 719 break; 720 721 case FFS_CLOSING: 722 break; 723 case FFS_DEACTIVATED: 724 break; 725 } 726 727 mutex_unlock(&ffs->mutex); 728 729 return mask; 730 } 731 732 static const struct file_operations ffs_ep0_operations = { 733 734 .open = ffs_ep0_open, 735 .write = ffs_ep0_write, 736 .read = ffs_ep0_read, 737 .release = ffs_ep0_release, 738 .unlocked_ioctl = ffs_ep0_ioctl, 739 .poll = ffs_ep0_poll, 740 }; 741 742 743 /* "Normal" endpoints operations ********************************************/ 744 745 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) 746 { 747 struct ffs_io_data *io_data = req->context; 748 749 if (req->status) 750 io_data->status = req->status; 751 else 752 io_data->status = req->actual; 753 754 complete(&io_data->done); 755 } 756 757 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter) 758 { 759 ssize_t ret = copy_to_iter(data, data_len, iter); 760 if (ret == data_len) 761 return ret; 762 763 if (iov_iter_count(iter)) 764 return -EFAULT; 765 766 /* 767 * Dear user space developer! 768 * 769 * TL;DR: To stop getting below error message in your kernel log, change 770 * user space code using functionfs to align read buffers to a max 771 * packet size. 772 * 773 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max 774 * packet size. When unaligned buffer is passed to functionfs, it 775 * internally uses a larger, aligned buffer so that such UDCs are happy. 776 * 777 * Unfortunately, this means that host may send more data than was 778 * requested in read(2) system call. f_fs doesn’t know what to do with 779 * that excess data so it simply drops it. 780 * 781 * Was the buffer aligned in the first place, no such problem would 782 * happen. 783 * 784 * Data may be dropped only in AIO reads. Synchronous reads are handled 785 * by splitting a request into multiple parts. This splitting may still 786 * be a problem though so it’s likely best to align the buffer 787 * regardless of it being AIO or not.. 788 * 789 * This only affects OUT endpoints, i.e. reading data with a read(2), 790 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not 791 * affected. 792 */ 793 pr_err("functionfs read size %d > requested size %zd, dropping excess data. " 794 "Align read buffer size to max packet size to avoid the problem.\n", 795 data_len, ret); 796 797 return ret; 798 } 799 800 /* 801 * allocate a virtually contiguous buffer and create a scatterlist describing it 802 * @sg_table - pointer to a place to be filled with sg_table contents 803 * @size - required buffer size 804 */ 805 static void *ffs_build_sg_list(struct sg_table *sgt, size_t sz) 806 { 807 struct page **pages; 808 void *vaddr, *ptr; 809 unsigned int n_pages; 810 int i; 811 812 vaddr = vmalloc(sz); 813 if (!vaddr) 814 return NULL; 815 816 n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT; 817 pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL); 818 if (!pages) { 819 vfree(vaddr); 820 821 return NULL; 822 } 823 for (i = 0, ptr = vaddr; i < n_pages; ++i, ptr += PAGE_SIZE) 824 pages[i] = vmalloc_to_page(ptr); 825 826 if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) { 827 kvfree(pages); 828 vfree(vaddr); 829 830 return NULL; 831 } 832 kvfree(pages); 833 834 return vaddr; 835 } 836 837 static inline void *ffs_alloc_buffer(struct ffs_io_data *io_data, 838 size_t data_len) 839 { 840 if (io_data->use_sg) 841 return ffs_build_sg_list(&io_data->sgt, data_len); 842 843 return kmalloc(data_len, GFP_KERNEL); 844 } 845 846 static inline void ffs_free_buffer(struct ffs_io_data *io_data) 847 { 848 if (!io_data->buf) 849 return; 850 851 if (io_data->use_sg) { 852 sg_free_table(&io_data->sgt); 853 vfree(io_data->buf); 854 } else { 855 kfree(io_data->buf); 856 } 857 } 858 859 static void ffs_user_copy_worker(struct work_struct *work) 860 { 861 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data, 862 work); 863 int ret = io_data->status; 864 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD; 865 866 if (io_data->read && ret > 0) { 867 kthread_use_mm(io_data->mm); 868 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); 869 kthread_unuse_mm(io_data->mm); 870 } 871 872 io_data->kiocb->ki_complete(io_data->kiocb, ret); 873 874 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd) 875 eventfd_signal(io_data->ffs->ffs_eventfd); 876 877 usb_ep_free_request(io_data->ep, io_data->req); 878 879 if (io_data->read) 880 kfree(io_data->to_free); 881 ffs_free_buffer(io_data); 882 kfree(io_data); 883 } 884 885 static void ffs_epfile_async_io_complete(struct usb_ep *_ep, 886 struct usb_request *req) 887 { 888 struct ffs_io_data *io_data = req->context; 889 struct ffs_data *ffs = io_data->ffs; 890 891 io_data->status = req->status ? req->status : req->actual; 892 893 INIT_WORK(&io_data->work, ffs_user_copy_worker); 894 queue_work(ffs->io_completion_wq, &io_data->work); 895 } 896 897 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile) 898 { 899 /* 900 * See comment in struct ffs_epfile for full read_buffer pointer 901 * synchronisation story. 902 */ 903 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP); 904 if (buf && buf != READ_BUFFER_DROP) 905 kfree(buf); 906 } 907 908 /* Assumes epfile->mutex is held. */ 909 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile, 910 struct iov_iter *iter) 911 { 912 /* 913 * Null out epfile->read_buffer so ffs_func_eps_disable does not free 914 * the buffer while we are using it. See comment in struct ffs_epfile 915 * for full read_buffer pointer synchronisation story. 916 */ 917 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL); 918 ssize_t ret; 919 if (!buf || buf == READ_BUFFER_DROP) 920 return 0; 921 922 ret = copy_to_iter(buf->data, buf->length, iter); 923 if (buf->length == ret) { 924 kfree(buf); 925 return ret; 926 } 927 928 if (iov_iter_count(iter)) { 929 ret = -EFAULT; 930 } else { 931 buf->length -= ret; 932 buf->data += ret; 933 } 934 935 if (cmpxchg(&epfile->read_buffer, NULL, buf)) 936 kfree(buf); 937 938 return ret; 939 } 940 941 /* Assumes epfile->mutex is held. */ 942 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile, 943 void *data, int data_len, 944 struct iov_iter *iter) 945 { 946 struct ffs_buffer *buf; 947 948 ssize_t ret = copy_to_iter(data, data_len, iter); 949 if (data_len == ret) 950 return ret; 951 952 if (iov_iter_count(iter)) 953 return -EFAULT; 954 955 /* See ffs_copy_to_iter for more context. */ 956 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.", 957 data_len, ret); 958 959 data_len -= ret; 960 buf = kmalloc(struct_size(buf, storage, data_len), GFP_KERNEL); 961 if (!buf) 962 return -ENOMEM; 963 buf->length = data_len; 964 buf->data = buf->storage; 965 memcpy(buf->storage, data + ret, flex_array_size(buf, storage, data_len)); 966 967 /* 968 * At this point read_buffer is NULL or READ_BUFFER_DROP (if 969 * ffs_func_eps_disable has been called in the meanwhile). See comment 970 * in struct ffs_epfile for full read_buffer pointer synchronisation 971 * story. 972 */ 973 if (cmpxchg(&epfile->read_buffer, NULL, buf)) 974 kfree(buf); 975 976 return ret; 977 } 978 979 static struct ffs_ep *ffs_epfile_wait_ep(struct file *file) 980 { 981 struct ffs_epfile *epfile = file->private_data; 982 struct ffs_ep *ep; 983 int ret; 984 985 /* Wait for endpoint to be enabled */ 986 ep = epfile->ep; 987 if (!ep) { 988 if (file->f_flags & O_NONBLOCK) 989 return ERR_PTR(-EAGAIN); 990 991 ret = wait_event_interruptible( 992 epfile->ffs->wait, (ep = epfile->ep)); 993 if (ret) 994 return ERR_PTR(-EINTR); 995 } 996 997 return ep; 998 } 999 1000 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) 1001 { 1002 struct ffs_epfile *epfile = file->private_data; 1003 struct usb_request *req; 1004 struct ffs_ep *ep; 1005 char *data = NULL; 1006 ssize_t ret, data_len = -EINVAL; 1007 int halt; 1008 1009 /* Are we still active? */ 1010 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 1011 return -ENODEV; 1012 1013 ep = ffs_epfile_wait_ep(file); 1014 if (IS_ERR(ep)) 1015 return PTR_ERR(ep); 1016 1017 /* Do we halt? */ 1018 halt = (!io_data->read == !epfile->in); 1019 if (halt && epfile->isoc) 1020 return -EINVAL; 1021 1022 /* We will be using request and read_buffer */ 1023 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK); 1024 if (ret) 1025 goto error; 1026 1027 /* Allocate & copy */ 1028 if (!halt) { 1029 struct usb_gadget *gadget; 1030 1031 /* 1032 * Do we have buffered data from previous partial read? Check 1033 * that for synchronous case only because we do not have 1034 * facility to ‘wake up’ a pending asynchronous read and push 1035 * buffered data to it which we would need to make things behave 1036 * consistently. 1037 */ 1038 if (!io_data->aio && io_data->read) { 1039 ret = __ffs_epfile_read_buffered(epfile, &io_data->data); 1040 if (ret) 1041 goto error_mutex; 1042 } 1043 1044 /* 1045 * if we _do_ wait above, the epfile->ffs->gadget might be NULL 1046 * before the waiting completes, so do not assign to 'gadget' 1047 * earlier 1048 */ 1049 gadget = epfile->ffs->gadget; 1050 1051 spin_lock_irq(&epfile->ffs->eps_lock); 1052 /* In the meantime, endpoint got disabled or changed. */ 1053 if (epfile->ep != ep) { 1054 ret = -ESHUTDOWN; 1055 goto error_lock; 1056 } 1057 data_len = iov_iter_count(&io_data->data); 1058 /* 1059 * Controller may require buffer size to be aligned to 1060 * maxpacketsize of an out endpoint. 1061 */ 1062 if (io_data->read) 1063 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len); 1064 1065 io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE; 1066 spin_unlock_irq(&epfile->ffs->eps_lock); 1067 1068 data = ffs_alloc_buffer(io_data, data_len); 1069 if (!data) { 1070 ret = -ENOMEM; 1071 goto error_mutex; 1072 } 1073 if (!io_data->read && 1074 !copy_from_iter_full(data, data_len, &io_data->data)) { 1075 ret = -EFAULT; 1076 goto error_mutex; 1077 } 1078 } 1079 1080 spin_lock_irq(&epfile->ffs->eps_lock); 1081 1082 if (epfile->ep != ep) { 1083 /* In the meantime, endpoint got disabled or changed. */ 1084 ret = -ESHUTDOWN; 1085 } else if (halt) { 1086 ret = usb_ep_set_halt(ep->ep); 1087 if (!ret) 1088 ret = -EBADMSG; 1089 } else if (data_len == -EINVAL) { 1090 /* 1091 * Sanity Check: even though data_len can't be used 1092 * uninitialized at the time I write this comment, some 1093 * compilers complain about this situation. 1094 * In order to keep the code clean from warnings, data_len is 1095 * being initialized to -EINVAL during its declaration, which 1096 * means we can't rely on compiler anymore to warn no future 1097 * changes won't result in data_len being used uninitialized. 1098 * For such reason, we're adding this redundant sanity check 1099 * here. 1100 */ 1101 WARN(1, "%s: data_len == -EINVAL\n", __func__); 1102 ret = -EINVAL; 1103 } else if (!io_data->aio) { 1104 bool interrupted = false; 1105 1106 req = ep->req; 1107 if (io_data->use_sg) { 1108 req->buf = NULL; 1109 req->sg = io_data->sgt.sgl; 1110 req->num_sgs = io_data->sgt.nents; 1111 } else { 1112 req->buf = data; 1113 req->num_sgs = 0; 1114 } 1115 req->length = data_len; 1116 1117 io_data->buf = data; 1118 1119 init_completion(&io_data->done); 1120 req->context = io_data; 1121 req->complete = ffs_epfile_io_complete; 1122 1123 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 1124 if (ret < 0) 1125 goto error_lock; 1126 1127 spin_unlock_irq(&epfile->ffs->eps_lock); 1128 1129 if (wait_for_completion_interruptible(&io_data->done)) { 1130 spin_lock_irq(&epfile->ffs->eps_lock); 1131 if (epfile->ep != ep) { 1132 ret = -ESHUTDOWN; 1133 goto error_lock; 1134 } 1135 /* 1136 * To avoid race condition with ffs_epfile_io_complete, 1137 * dequeue the request first then check 1138 * status. usb_ep_dequeue API should guarantee no race 1139 * condition with req->complete callback. 1140 */ 1141 usb_ep_dequeue(ep->ep, req); 1142 spin_unlock_irq(&epfile->ffs->eps_lock); 1143 wait_for_completion(&io_data->done); 1144 interrupted = io_data->status < 0; 1145 } 1146 1147 if (interrupted) 1148 ret = -EINTR; 1149 else if (io_data->read && io_data->status > 0) 1150 ret = __ffs_epfile_read_data(epfile, data, io_data->status, 1151 &io_data->data); 1152 else 1153 ret = io_data->status; 1154 goto error_mutex; 1155 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) { 1156 ret = -ENOMEM; 1157 } else { 1158 if (io_data->use_sg) { 1159 req->buf = NULL; 1160 req->sg = io_data->sgt.sgl; 1161 req->num_sgs = io_data->sgt.nents; 1162 } else { 1163 req->buf = data; 1164 req->num_sgs = 0; 1165 } 1166 req->length = data_len; 1167 1168 io_data->buf = data; 1169 io_data->ep = ep->ep; 1170 io_data->req = req; 1171 io_data->ffs = epfile->ffs; 1172 1173 req->context = io_data; 1174 req->complete = ffs_epfile_async_io_complete; 1175 1176 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 1177 if (ret) { 1178 io_data->req = NULL; 1179 usb_ep_free_request(ep->ep, req); 1180 goto error_lock; 1181 } 1182 1183 ret = -EIOCBQUEUED; 1184 /* 1185 * Do not kfree the buffer in this function. It will be freed 1186 * by ffs_user_copy_worker. 1187 */ 1188 data = NULL; 1189 } 1190 1191 error_lock: 1192 spin_unlock_irq(&epfile->ffs->eps_lock); 1193 error_mutex: 1194 mutex_unlock(&epfile->mutex); 1195 error: 1196 if (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */ 1197 ffs_free_buffer(io_data); 1198 return ret; 1199 } 1200 1201 static int 1202 ffs_epfile_open(struct inode *inode, struct file *file) 1203 { 1204 struct ffs_data *ffs = inode->i_sb->s_fs_info; 1205 struct ffs_epfile *epfile; 1206 1207 spin_lock_irq(&ffs->eps_lock); 1208 if (!ffs->opened) { 1209 spin_unlock_irq(&ffs->eps_lock); 1210 return -ENODEV; 1211 } 1212 /* 1213 * we want the state to be FFS_ACTIVE; FFS_ACTIVE alone is 1214 * not enough, though - we might have been through FFS_CLOSING 1215 * and back to FFS_ACTIVE, with our file already removed. 1216 */ 1217 epfile = smp_load_acquire(&inode->i_private); 1218 if (unlikely(ffs->state != FFS_ACTIVE || !epfile)) { 1219 spin_unlock_irq(&ffs->eps_lock); 1220 return -ENODEV; 1221 } 1222 ffs->opened++; 1223 spin_unlock_irq(&ffs->eps_lock); 1224 1225 file->private_data = epfile; 1226 return stream_open(inode, file); 1227 } 1228 1229 static int ffs_aio_cancel(struct kiocb *kiocb) 1230 { 1231 struct ffs_io_data *io_data = kiocb->private; 1232 int value; 1233 1234 if (io_data && io_data->ep && io_data->req) 1235 value = usb_ep_dequeue(io_data->ep, io_data->req); 1236 else 1237 value = -EINVAL; 1238 1239 return value; 1240 } 1241 1242 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from) 1243 { 1244 struct ffs_io_data io_data, *p = &io_data; 1245 ssize_t res; 1246 1247 if (!is_sync_kiocb(kiocb)) { 1248 p = kzalloc(sizeof(io_data), GFP_KERNEL); 1249 if (!p) 1250 return -ENOMEM; 1251 p->aio = true; 1252 } else { 1253 memset(p, 0, sizeof(*p)); 1254 p->aio = false; 1255 } 1256 1257 p->read = false; 1258 p->kiocb = kiocb; 1259 p->data = *from; 1260 p->mm = current->mm; 1261 1262 kiocb->private = p; 1263 1264 if (p->aio) 1265 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 1266 1267 res = ffs_epfile_io(kiocb->ki_filp, p); 1268 if (res == -EIOCBQUEUED) 1269 return res; 1270 if (p->aio) 1271 kfree(p); 1272 else 1273 *from = p->data; 1274 return res; 1275 } 1276 1277 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) 1278 { 1279 struct ffs_io_data io_data, *p = &io_data; 1280 ssize_t res; 1281 1282 if (!is_sync_kiocb(kiocb)) { 1283 p = kzalloc(sizeof(io_data), GFP_KERNEL); 1284 if (!p) 1285 return -ENOMEM; 1286 p->aio = true; 1287 } else { 1288 memset(p, 0, sizeof(*p)); 1289 p->aio = false; 1290 } 1291 1292 p->read = true; 1293 p->kiocb = kiocb; 1294 if (p->aio) { 1295 p->to_free = dup_iter(&p->data, to, GFP_KERNEL); 1296 if (!iter_is_ubuf(&p->data) && !p->to_free) { 1297 kfree(p); 1298 return -ENOMEM; 1299 } 1300 } else { 1301 p->data = *to; 1302 p->to_free = NULL; 1303 } 1304 p->mm = current->mm; 1305 1306 kiocb->private = p; 1307 1308 if (p->aio) 1309 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 1310 1311 res = ffs_epfile_io(kiocb->ki_filp, p); 1312 if (res == -EIOCBQUEUED) 1313 return res; 1314 1315 if (p->aio) { 1316 kfree(p->to_free); 1317 kfree(p); 1318 } else { 1319 *to = p->data; 1320 } 1321 return res; 1322 } 1323 1324 static void ffs_dmabuf_release(struct kref *ref) 1325 { 1326 struct ffs_dmabuf_priv *priv = container_of(ref, struct ffs_dmabuf_priv, ref); 1327 struct dma_buf_attachment *attach = priv->attach; 1328 struct dma_buf *dmabuf = attach->dmabuf; 1329 1330 pr_vdebug("FFS DMABUF release\n"); 1331 dma_buf_unmap_attachment_unlocked(attach, priv->sgt, priv->dir); 1332 1333 dma_buf_detach(attach->dmabuf, attach); 1334 dma_buf_put(dmabuf); 1335 kfree(priv); 1336 } 1337 1338 static void ffs_dmabuf_get(struct dma_buf_attachment *attach) 1339 { 1340 struct ffs_dmabuf_priv *priv = attach->importer_priv; 1341 1342 kref_get(&priv->ref); 1343 } 1344 1345 static void ffs_dmabuf_put(struct dma_buf_attachment *attach) 1346 { 1347 struct ffs_dmabuf_priv *priv = attach->importer_priv; 1348 1349 kref_put(&priv->ref, ffs_dmabuf_release); 1350 } 1351 1352 static int 1353 ffs_epfile_release(struct inode *inode, struct file *file) 1354 { 1355 struct ffs_epfile *epfile = file->private_data; 1356 struct ffs_dmabuf_priv *priv, *tmp; 1357 struct ffs_data *ffs = epfile->ffs; 1358 1359 mutex_lock(&epfile->dmabufs_mutex); 1360 1361 /* Close all attached DMABUFs */ 1362 list_for_each_entry_safe(priv, tmp, &epfile->dmabufs, entry) { 1363 /* Cancel any pending transfer */ 1364 spin_lock_irq(&ffs->eps_lock); 1365 if (priv->ep && priv->req) 1366 usb_ep_dequeue(priv->ep, priv->req); 1367 spin_unlock_irq(&ffs->eps_lock); 1368 1369 list_del(&priv->entry); 1370 ffs_dmabuf_put(priv->attach); 1371 } 1372 1373 mutex_unlock(&epfile->dmabufs_mutex); 1374 1375 __ffs_epfile_read_buffer_free(epfile); 1376 ffs_data_closed(epfile->ffs); 1377 1378 return 0; 1379 } 1380 1381 static void ffs_dmabuf_cleanup(struct work_struct *work) 1382 { 1383 struct ffs_dma_fence *dma_fence = 1384 container_of(work, struct ffs_dma_fence, work); 1385 struct ffs_dmabuf_priv *priv = dma_fence->priv; 1386 struct dma_buf_attachment *attach = priv->attach; 1387 struct dma_fence *fence = &dma_fence->base; 1388 1389 ffs_dmabuf_put(attach); 1390 dma_fence_put(fence); 1391 } 1392 1393 static void ffs_dmabuf_signal_done(struct ffs_dma_fence *dma_fence, int ret) 1394 { 1395 struct ffs_dmabuf_priv *priv = dma_fence->priv; 1396 struct dma_fence *fence = &dma_fence->base; 1397 bool cookie = dma_fence_begin_signalling(); 1398 1399 dma_fence_get(fence); 1400 fence->error = ret; 1401 dma_fence_signal(fence); 1402 dma_fence_end_signalling(cookie); 1403 1404 /* 1405 * The fence will be unref'd in ffs_dmabuf_cleanup. 1406 * It can't be done here, as the unref functions might try to lock 1407 * the resv object, which would deadlock. 1408 */ 1409 INIT_WORK(&dma_fence->work, ffs_dmabuf_cleanup); 1410 queue_work(priv->ffs->io_completion_wq, &dma_fence->work); 1411 } 1412 1413 static void ffs_epfile_dmabuf_io_complete(struct usb_ep *ep, 1414 struct usb_request *req) 1415 { 1416 pr_vdebug("FFS: DMABUF transfer complete, status=%d\n", req->status); 1417 ffs_dmabuf_signal_done(req->context, req->status); 1418 usb_ep_free_request(ep, req); 1419 } 1420 1421 static const char *ffs_dmabuf_get_driver_name(struct dma_fence *fence) 1422 { 1423 return "functionfs"; 1424 } 1425 1426 static const char *ffs_dmabuf_get_timeline_name(struct dma_fence *fence) 1427 { 1428 return ""; 1429 } 1430 1431 static void ffs_dmabuf_fence_release(struct dma_fence *fence) 1432 { 1433 struct ffs_dma_fence *dma_fence = 1434 container_of(fence, struct ffs_dma_fence, base); 1435 1436 kfree(dma_fence); 1437 } 1438 1439 static const struct dma_fence_ops ffs_dmabuf_fence_ops = { 1440 .get_driver_name = ffs_dmabuf_get_driver_name, 1441 .get_timeline_name = ffs_dmabuf_get_timeline_name, 1442 .release = ffs_dmabuf_fence_release, 1443 }; 1444 1445 static int ffs_dma_resv_lock(struct dma_buf *dmabuf, bool nonblock) 1446 { 1447 if (!nonblock) 1448 return dma_resv_lock_interruptible(dmabuf->resv, NULL); 1449 1450 if (!dma_resv_trylock(dmabuf->resv)) 1451 return -EBUSY; 1452 1453 return 0; 1454 } 1455 1456 static struct dma_buf_attachment * 1457 ffs_dmabuf_find_attachment(struct ffs_epfile *epfile, struct dma_buf *dmabuf) 1458 { 1459 struct device *dev = epfile->ffs->gadget->dev.parent; 1460 struct dma_buf_attachment *attach = NULL; 1461 struct ffs_dmabuf_priv *priv; 1462 1463 mutex_lock(&epfile->dmabufs_mutex); 1464 1465 list_for_each_entry(priv, &epfile->dmabufs, entry) { 1466 if (priv->attach->dev == dev 1467 && priv->attach->dmabuf == dmabuf) { 1468 attach = priv->attach; 1469 break; 1470 } 1471 } 1472 1473 if (attach) 1474 ffs_dmabuf_get(attach); 1475 1476 mutex_unlock(&epfile->dmabufs_mutex); 1477 1478 return attach ?: ERR_PTR(-EPERM); 1479 } 1480 1481 static int ffs_dmabuf_attach(struct file *file, int fd) 1482 { 1483 bool nonblock = file->f_flags & O_NONBLOCK; 1484 struct ffs_epfile *epfile = file->private_data; 1485 struct usb_gadget *gadget = epfile->ffs->gadget; 1486 struct dma_buf_attachment *attach; 1487 struct ffs_dmabuf_priv *priv; 1488 enum dma_data_direction dir; 1489 struct sg_table *sg_table; 1490 struct dma_buf *dmabuf; 1491 int err; 1492 1493 if (!gadget || !gadget->sg_supported) 1494 return -EPERM; 1495 1496 dmabuf = dma_buf_get(fd); 1497 if (IS_ERR(dmabuf)) 1498 return PTR_ERR(dmabuf); 1499 1500 attach = dma_buf_attach(dmabuf, gadget->dev.parent); 1501 if (IS_ERR(attach)) { 1502 err = PTR_ERR(attach); 1503 goto err_dmabuf_put; 1504 } 1505 1506 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 1507 if (!priv) { 1508 err = -ENOMEM; 1509 goto err_dmabuf_detach; 1510 } 1511 1512 dir = epfile->in ? DMA_TO_DEVICE : DMA_FROM_DEVICE; 1513 1514 err = ffs_dma_resv_lock(dmabuf, nonblock); 1515 if (err) 1516 goto err_free_priv; 1517 1518 sg_table = dma_buf_map_attachment(attach, dir); 1519 dma_resv_unlock(dmabuf->resv); 1520 1521 if (IS_ERR(sg_table)) { 1522 err = PTR_ERR(sg_table); 1523 goto err_free_priv; 1524 } 1525 1526 attach->importer_priv = priv; 1527 1528 priv->sgt = sg_table; 1529 priv->dir = dir; 1530 priv->ffs = epfile->ffs; 1531 priv->attach = attach; 1532 spin_lock_init(&priv->lock); 1533 kref_init(&priv->ref); 1534 priv->context = dma_fence_context_alloc(1); 1535 1536 mutex_lock(&epfile->dmabufs_mutex); 1537 list_add(&priv->entry, &epfile->dmabufs); 1538 mutex_unlock(&epfile->dmabufs_mutex); 1539 1540 return 0; 1541 1542 err_free_priv: 1543 kfree(priv); 1544 err_dmabuf_detach: 1545 dma_buf_detach(dmabuf, attach); 1546 err_dmabuf_put: 1547 dma_buf_put(dmabuf); 1548 1549 return err; 1550 } 1551 1552 static int ffs_dmabuf_detach(struct file *file, int fd) 1553 { 1554 struct ffs_epfile *epfile = file->private_data; 1555 struct ffs_data *ffs = epfile->ffs; 1556 struct device *dev = ffs->gadget->dev.parent; 1557 struct ffs_dmabuf_priv *priv, *tmp; 1558 struct dma_buf *dmabuf; 1559 int ret = -EPERM; 1560 1561 dmabuf = dma_buf_get(fd); 1562 if (IS_ERR(dmabuf)) 1563 return PTR_ERR(dmabuf); 1564 1565 mutex_lock(&epfile->dmabufs_mutex); 1566 1567 list_for_each_entry_safe(priv, tmp, &epfile->dmabufs, entry) { 1568 if (priv->attach->dev == dev 1569 && priv->attach->dmabuf == dmabuf) { 1570 /* Cancel any pending transfer */ 1571 spin_lock_irq(&ffs->eps_lock); 1572 if (priv->ep && priv->req) 1573 usb_ep_dequeue(priv->ep, priv->req); 1574 spin_unlock_irq(&ffs->eps_lock); 1575 1576 list_del(&priv->entry); 1577 1578 /* Unref the reference from ffs_dmabuf_attach() */ 1579 ffs_dmabuf_put(priv->attach); 1580 ret = 0; 1581 break; 1582 } 1583 } 1584 1585 mutex_unlock(&epfile->dmabufs_mutex); 1586 dma_buf_put(dmabuf); 1587 1588 return ret; 1589 } 1590 1591 static int ffs_dmabuf_transfer(struct file *file, 1592 const struct usb_ffs_dmabuf_transfer_req *req) 1593 { 1594 bool nonblock = file->f_flags & O_NONBLOCK; 1595 struct ffs_epfile *epfile = file->private_data; 1596 struct dma_buf_attachment *attach; 1597 struct ffs_dmabuf_priv *priv; 1598 struct ffs_dma_fence *fence; 1599 struct usb_request *usb_req; 1600 enum dma_resv_usage resv_dir; 1601 struct dma_buf *dmabuf; 1602 unsigned long timeout; 1603 struct ffs_ep *ep; 1604 bool cookie; 1605 u32 seqno; 1606 long retl; 1607 int ret; 1608 1609 if (req->flags & ~USB_FFS_DMABUF_TRANSFER_MASK) 1610 return -EINVAL; 1611 1612 dmabuf = dma_buf_get(req->fd); 1613 if (IS_ERR(dmabuf)) 1614 return PTR_ERR(dmabuf); 1615 1616 if (req->length > dmabuf->size || req->length == 0) { 1617 ret = -EINVAL; 1618 goto err_dmabuf_put; 1619 } 1620 1621 attach = ffs_dmabuf_find_attachment(epfile, dmabuf); 1622 if (IS_ERR(attach)) { 1623 ret = PTR_ERR(attach); 1624 goto err_dmabuf_put; 1625 } 1626 1627 priv = attach->importer_priv; 1628 1629 ep = ffs_epfile_wait_ep(file); 1630 if (IS_ERR(ep)) { 1631 ret = PTR_ERR(ep); 1632 goto err_attachment_put; 1633 } 1634 1635 ret = ffs_dma_resv_lock(dmabuf, nonblock); 1636 if (ret) 1637 goto err_attachment_put; 1638 1639 /* Make sure we don't have writers */ 1640 timeout = nonblock ? 0 : msecs_to_jiffies(DMABUF_ENQUEUE_TIMEOUT_MS); 1641 retl = dma_resv_wait_timeout(dmabuf->resv, 1642 dma_resv_usage_rw(!epfile->in), 1643 true, timeout); 1644 if (retl == 0) 1645 retl = -EBUSY; 1646 if (retl < 0) { 1647 ret = (int)retl; 1648 goto err_resv_unlock; 1649 } 1650 1651 ret = dma_resv_reserve_fences(dmabuf->resv, 1); 1652 if (ret) 1653 goto err_resv_unlock; 1654 1655 fence = kmalloc(sizeof(*fence), GFP_KERNEL); 1656 if (!fence) { 1657 ret = -ENOMEM; 1658 goto err_resv_unlock; 1659 } 1660 1661 fence->priv = priv; 1662 1663 spin_lock_irq(&epfile->ffs->eps_lock); 1664 1665 /* In the meantime, endpoint got disabled or changed. */ 1666 if (epfile->ep != ep) { 1667 ret = -ESHUTDOWN; 1668 goto err_fence_put; 1669 } 1670 1671 usb_req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC); 1672 if (!usb_req) { 1673 ret = -ENOMEM; 1674 goto err_fence_put; 1675 } 1676 1677 /* 1678 * usb_ep_queue() guarantees that all transfers are processed in the 1679 * order they are enqueued, so we can use a simple incrementing 1680 * sequence number for the dma_fence. 1681 */ 1682 seqno = atomic_add_return(1, &epfile->seqno); 1683 1684 dma_fence_init(&fence->base, &ffs_dmabuf_fence_ops, 1685 &priv->lock, priv->context, seqno); 1686 1687 resv_dir = epfile->in ? DMA_RESV_USAGE_READ : DMA_RESV_USAGE_WRITE; 1688 1689 dma_resv_add_fence(dmabuf->resv, &fence->base, resv_dir); 1690 dma_resv_unlock(dmabuf->resv); 1691 1692 /* Now that the dma_fence is in place, queue the transfer. */ 1693 1694 usb_req->length = req->length; 1695 usb_req->buf = NULL; 1696 usb_req->sg = priv->sgt->sgl; 1697 usb_req->num_sgs = sg_nents_for_len(priv->sgt->sgl, req->length); 1698 usb_req->sg_was_mapped = true; 1699 usb_req->context = fence; 1700 usb_req->complete = ffs_epfile_dmabuf_io_complete; 1701 1702 cookie = dma_fence_begin_signalling(); 1703 ret = usb_ep_queue(ep->ep, usb_req, GFP_ATOMIC); 1704 dma_fence_end_signalling(cookie); 1705 if (!ret) { 1706 priv->req = usb_req; 1707 priv->ep = ep->ep; 1708 } else { 1709 pr_warn("FFS: Failed to queue DMABUF: %d\n", ret); 1710 ffs_dmabuf_signal_done(fence, ret); 1711 usb_ep_free_request(ep->ep, usb_req); 1712 } 1713 1714 spin_unlock_irq(&epfile->ffs->eps_lock); 1715 dma_buf_put(dmabuf); 1716 1717 return ret; 1718 1719 err_fence_put: 1720 spin_unlock_irq(&epfile->ffs->eps_lock); 1721 dma_fence_put(&fence->base); 1722 err_resv_unlock: 1723 dma_resv_unlock(dmabuf->resv); 1724 err_attachment_put: 1725 ffs_dmabuf_put(attach); 1726 err_dmabuf_put: 1727 dma_buf_put(dmabuf); 1728 1729 return ret; 1730 } 1731 1732 static long ffs_epfile_ioctl(struct file *file, unsigned code, 1733 unsigned long value) 1734 { 1735 struct ffs_epfile *epfile = file->private_data; 1736 struct ffs_ep *ep; 1737 int ret; 1738 1739 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 1740 return -ENODEV; 1741 1742 switch (code) { 1743 case FUNCTIONFS_DMABUF_ATTACH: 1744 { 1745 int fd; 1746 1747 if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) 1748 return -EFAULT; 1749 1750 return ffs_dmabuf_attach(file, fd); 1751 } 1752 case FUNCTIONFS_DMABUF_DETACH: 1753 { 1754 int fd; 1755 1756 if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) 1757 return -EFAULT; 1758 1759 return ffs_dmabuf_detach(file, fd); 1760 } 1761 case FUNCTIONFS_DMABUF_TRANSFER: 1762 { 1763 struct usb_ffs_dmabuf_transfer_req req; 1764 1765 if (copy_from_user(&req, (void __user *)value, sizeof(req))) 1766 return -EFAULT; 1767 1768 return ffs_dmabuf_transfer(file, &req); 1769 } 1770 default: 1771 break; 1772 } 1773 1774 /* Wait for endpoint to be enabled */ 1775 ep = ffs_epfile_wait_ep(file); 1776 if (IS_ERR(ep)) 1777 return PTR_ERR(ep); 1778 1779 spin_lock_irq(&epfile->ffs->eps_lock); 1780 1781 /* In the meantime, endpoint got disabled or changed. */ 1782 if (epfile->ep != ep) { 1783 spin_unlock_irq(&epfile->ffs->eps_lock); 1784 return -ESHUTDOWN; 1785 } 1786 1787 switch (code) { 1788 case FUNCTIONFS_FIFO_STATUS: 1789 ret = usb_ep_fifo_status(epfile->ep->ep); 1790 break; 1791 case FUNCTIONFS_FIFO_FLUSH: 1792 usb_ep_fifo_flush(epfile->ep->ep); 1793 ret = 0; 1794 break; 1795 case FUNCTIONFS_CLEAR_HALT: 1796 ret = usb_ep_clear_halt(epfile->ep->ep); 1797 break; 1798 case FUNCTIONFS_ENDPOINT_REVMAP: 1799 ret = epfile->ep->num; 1800 break; 1801 case FUNCTIONFS_ENDPOINT_DESC: 1802 { 1803 int desc_idx; 1804 struct usb_endpoint_descriptor desc1, *desc; 1805 1806 switch (epfile->ffs->gadget->speed) { 1807 case USB_SPEED_SUPER: 1808 case USB_SPEED_SUPER_PLUS: 1809 desc_idx = 2; 1810 break; 1811 case USB_SPEED_HIGH: 1812 desc_idx = 1; 1813 break; 1814 default: 1815 desc_idx = 0; 1816 } 1817 1818 desc = epfile->ep->descs[desc_idx]; 1819 memcpy(&desc1, desc, desc->bLength); 1820 1821 spin_unlock_irq(&epfile->ffs->eps_lock); 1822 ret = copy_to_user((void __user *)value, &desc1, desc1.bLength); 1823 if (ret) 1824 ret = -EFAULT; 1825 return ret; 1826 } 1827 default: 1828 ret = -ENOTTY; 1829 } 1830 spin_unlock_irq(&epfile->ffs->eps_lock); 1831 1832 return ret; 1833 } 1834 1835 static const struct file_operations ffs_epfile_operations = { 1836 1837 .open = ffs_epfile_open, 1838 .write_iter = ffs_epfile_write_iter, 1839 .read_iter = ffs_epfile_read_iter, 1840 .release = ffs_epfile_release, 1841 .unlocked_ioctl = ffs_epfile_ioctl, 1842 .compat_ioctl = compat_ptr_ioctl, 1843 }; 1844 1845 1846 /* File system and super block operations ***********************************/ 1847 1848 /* 1849 * Mounting the file system creates a controller file, used first for 1850 * function configuration then later for event monitoring. 1851 */ 1852 1853 static struct inode *__must_check 1854 ffs_sb_make_inode(struct super_block *sb, void *data, 1855 const struct file_operations *fops, 1856 const struct inode_operations *iops, 1857 struct ffs_file_perms *perms) 1858 { 1859 struct inode *inode; 1860 1861 inode = new_inode(sb); 1862 1863 if (inode) { 1864 struct timespec64 ts = inode_set_ctime_current(inode); 1865 1866 inode->i_ino = get_next_ino(); 1867 inode->i_mode = perms->mode; 1868 inode->i_uid = perms->uid; 1869 inode->i_gid = perms->gid; 1870 inode_set_atime_to_ts(inode, ts); 1871 inode_set_mtime_to_ts(inode, ts); 1872 inode->i_private = data; 1873 if (fops) 1874 inode->i_fop = fops; 1875 if (iops) 1876 inode->i_op = iops; 1877 } 1878 1879 return inode; 1880 } 1881 1882 /* Create "regular" file */ 1883 static int ffs_sb_create_file(struct super_block *sb, const char *name, 1884 void *data, const struct file_operations *fops) 1885 { 1886 struct ffs_data *ffs = sb->s_fs_info; 1887 struct dentry *dentry; 1888 struct inode *inode; 1889 1890 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms); 1891 if (!inode) 1892 return -ENOMEM; 1893 dentry = simple_start_creating(sb->s_root, name); 1894 if (IS_ERR(dentry)) { 1895 iput(inode); 1896 return PTR_ERR(dentry); 1897 } 1898 1899 d_make_persistent(dentry, inode); 1900 1901 simple_done_creating(dentry); 1902 return 0; 1903 } 1904 1905 /* Super block */ 1906 static const struct super_operations ffs_sb_operations = { 1907 .statfs = simple_statfs, 1908 .drop_inode = inode_just_drop, 1909 }; 1910 1911 struct ffs_sb_fill_data { 1912 struct ffs_file_perms perms; 1913 umode_t root_mode; 1914 const char *dev_name; 1915 bool no_disconnect; 1916 struct ffs_data *ffs_data; 1917 }; 1918 1919 static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc) 1920 { 1921 struct ffs_sb_fill_data *data = fc->fs_private; 1922 struct inode *inode; 1923 struct ffs_data *ffs = data->ffs_data; 1924 1925 ffs->sb = sb; 1926 data->ffs_data = NULL; 1927 sb->s_fs_info = ffs; 1928 sb->s_blocksize = PAGE_SIZE; 1929 sb->s_blocksize_bits = PAGE_SHIFT; 1930 sb->s_magic = FUNCTIONFS_MAGIC; 1931 sb->s_op = &ffs_sb_operations; 1932 sb->s_time_gran = 1; 1933 1934 /* Root inode */ 1935 data->perms.mode = data->root_mode; 1936 inode = ffs_sb_make_inode(sb, NULL, 1937 &simple_dir_operations, 1938 &simple_dir_inode_operations, 1939 &data->perms); 1940 sb->s_root = d_make_root(inode); 1941 if (!sb->s_root) 1942 return -ENOMEM; 1943 1944 /* EP0 file */ 1945 return ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations); 1946 } 1947 1948 enum { 1949 Opt_no_disconnect, 1950 Opt_rmode, 1951 Opt_fmode, 1952 Opt_mode, 1953 Opt_uid, 1954 Opt_gid, 1955 }; 1956 1957 static const struct fs_parameter_spec ffs_fs_fs_parameters[] = { 1958 fsparam_bool ("no_disconnect", Opt_no_disconnect), 1959 fsparam_u32 ("rmode", Opt_rmode), 1960 fsparam_u32 ("fmode", Opt_fmode), 1961 fsparam_u32 ("mode", Opt_mode), 1962 fsparam_u32 ("uid", Opt_uid), 1963 fsparam_u32 ("gid", Opt_gid), 1964 {} 1965 }; 1966 1967 static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param) 1968 { 1969 struct ffs_sb_fill_data *data = fc->fs_private; 1970 struct fs_parse_result result; 1971 int opt; 1972 1973 opt = fs_parse(fc, ffs_fs_fs_parameters, param, &result); 1974 if (opt < 0) 1975 return opt; 1976 1977 switch (opt) { 1978 case Opt_no_disconnect: 1979 data->no_disconnect = result.boolean; 1980 break; 1981 case Opt_rmode: 1982 data->root_mode = (result.uint_32 & 0555) | S_IFDIR; 1983 break; 1984 case Opt_fmode: 1985 data->perms.mode = (result.uint_32 & 0666) | S_IFREG; 1986 break; 1987 case Opt_mode: 1988 data->root_mode = (result.uint_32 & 0555) | S_IFDIR; 1989 data->perms.mode = (result.uint_32 & 0666) | S_IFREG; 1990 break; 1991 1992 case Opt_uid: 1993 data->perms.uid = make_kuid(current_user_ns(), result.uint_32); 1994 if (!uid_valid(data->perms.uid)) 1995 goto unmapped_value; 1996 break; 1997 case Opt_gid: 1998 data->perms.gid = make_kgid(current_user_ns(), result.uint_32); 1999 if (!gid_valid(data->perms.gid)) 2000 goto unmapped_value; 2001 break; 2002 2003 default: 2004 return -ENOPARAM; 2005 } 2006 2007 return 0; 2008 2009 unmapped_value: 2010 return invalf(fc, "%s: unmapped value: %u", param->key, result.uint_32); 2011 } 2012 2013 /* 2014 * Set up the superblock for a mount. 2015 */ 2016 static int ffs_fs_get_tree(struct fs_context *fc) 2017 { 2018 struct ffs_sb_fill_data *ctx = fc->fs_private; 2019 struct ffs_data *ffs; 2020 int ret; 2021 2022 if (!fc->source) 2023 return invalf(fc, "No source specified"); 2024 2025 ffs = ffs_data_new(fc->source); 2026 if (!ffs) 2027 return -ENOMEM; 2028 ffs->file_perms = ctx->perms; 2029 ffs->no_disconnect = ctx->no_disconnect; 2030 2031 ffs->dev_name = kstrdup(fc->source, GFP_KERNEL); 2032 if (!ffs->dev_name) { 2033 ffs_data_put(ffs); 2034 return -ENOMEM; 2035 } 2036 2037 ret = ffs_acquire_dev(ffs->dev_name, ffs); 2038 if (ret) { 2039 ffs_data_put(ffs); 2040 return ret; 2041 } 2042 2043 ctx->ffs_data = ffs; 2044 return get_tree_nodev(fc, ffs_sb_fill); 2045 } 2046 2047 static void ffs_fs_free_fc(struct fs_context *fc) 2048 { 2049 struct ffs_sb_fill_data *ctx = fc->fs_private; 2050 2051 if (ctx) { 2052 if (ctx->ffs_data) { 2053 ffs_data_put(ctx->ffs_data); 2054 } 2055 2056 kfree(ctx); 2057 } 2058 } 2059 2060 static const struct fs_context_operations ffs_fs_context_ops = { 2061 .free = ffs_fs_free_fc, 2062 .parse_param = ffs_fs_parse_param, 2063 .get_tree = ffs_fs_get_tree, 2064 }; 2065 2066 static int ffs_fs_init_fs_context(struct fs_context *fc) 2067 { 2068 struct ffs_sb_fill_data *ctx; 2069 2070 ctx = kzalloc(sizeof(struct ffs_sb_fill_data), GFP_KERNEL); 2071 if (!ctx) 2072 return -ENOMEM; 2073 2074 ctx->perms.mode = S_IFREG | 0600; 2075 ctx->perms.uid = GLOBAL_ROOT_UID; 2076 ctx->perms.gid = GLOBAL_ROOT_GID; 2077 ctx->root_mode = S_IFDIR | 0500; 2078 ctx->no_disconnect = false; 2079 2080 fc->fs_private = ctx; 2081 fc->ops = &ffs_fs_context_ops; 2082 return 0; 2083 } 2084 2085 static void 2086 ffs_fs_kill_sb(struct super_block *sb) 2087 { 2088 kill_anon_super(sb); 2089 if (sb->s_fs_info) { 2090 struct ffs_data *ffs = sb->s_fs_info; 2091 ffs->state = FFS_CLOSING; 2092 ffs_data_reset(ffs); 2093 // no configfs accesses from that point on, 2094 // so no further schedule_work() is possible 2095 cancel_work_sync(&ffs->reset_work); 2096 ffs_data_put(ffs); 2097 } 2098 } 2099 2100 static struct file_system_type ffs_fs_type = { 2101 .owner = THIS_MODULE, 2102 .name = "functionfs", 2103 .init_fs_context = ffs_fs_init_fs_context, 2104 .parameters = ffs_fs_fs_parameters, 2105 .kill_sb = ffs_fs_kill_sb, 2106 }; 2107 MODULE_ALIAS_FS("functionfs"); 2108 2109 2110 /* Driver's main init/cleanup functions *************************************/ 2111 2112 static int functionfs_init(void) 2113 { 2114 int ret; 2115 2116 ret = register_filesystem(&ffs_fs_type); 2117 if (!ret) 2118 pr_info("file system registered\n"); 2119 else 2120 pr_err("failed registering file system (%d)\n", ret); 2121 2122 return ret; 2123 } 2124 2125 static void functionfs_cleanup(void) 2126 { 2127 pr_info("unloading\n"); 2128 unregister_filesystem(&ffs_fs_type); 2129 } 2130 2131 2132 /* ffs_data and ffs_function construction and destruction code **************/ 2133 2134 static void ffs_data_clear(struct ffs_data *ffs); 2135 2136 static void ffs_data_get(struct ffs_data *ffs) 2137 { 2138 refcount_inc(&ffs->ref); 2139 } 2140 2141 static void ffs_data_put(struct ffs_data *ffs) 2142 { 2143 if (refcount_dec_and_test(&ffs->ref)) { 2144 pr_info("%s(): freeing\n", __func__); 2145 ffs_data_clear(ffs); 2146 ffs_release_dev(ffs->private_data); 2147 BUG_ON(waitqueue_active(&ffs->ev.waitq) || 2148 swait_active(&ffs->ep0req_completion.wait) || 2149 waitqueue_active(&ffs->wait)); 2150 destroy_workqueue(ffs->io_completion_wq); 2151 kfree(ffs->dev_name); 2152 kfree(ffs); 2153 } 2154 } 2155 2156 static void ffs_data_closed(struct ffs_data *ffs) 2157 { 2158 spin_lock_irq(&ffs->eps_lock); 2159 if (--ffs->opened) { // not the last opener? 2160 spin_unlock_irq(&ffs->eps_lock); 2161 return; 2162 } 2163 if (ffs->no_disconnect) { 2164 struct ffs_epfile *epfiles; 2165 2166 ffs->state = FFS_DEACTIVATED; 2167 epfiles = ffs->epfiles; 2168 ffs->epfiles = NULL; 2169 spin_unlock_irq(&ffs->eps_lock); 2170 2171 if (epfiles) 2172 ffs_epfiles_destroy(ffs->sb, epfiles, 2173 ffs->eps_count); 2174 2175 if (ffs->setup_state == FFS_SETUP_PENDING) 2176 __ffs_ep0_stall(ffs); 2177 } else { 2178 ffs->state = FFS_CLOSING; 2179 spin_unlock_irq(&ffs->eps_lock); 2180 ffs_data_reset(ffs); 2181 } 2182 } 2183 2184 static struct ffs_data *ffs_data_new(const char *dev_name) 2185 { 2186 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL); 2187 if (!ffs) 2188 return NULL; 2189 2190 ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name); 2191 if (!ffs->io_completion_wq) { 2192 kfree(ffs); 2193 return NULL; 2194 } 2195 2196 refcount_set(&ffs->ref, 1); 2197 ffs->opened = 0; 2198 ffs->state = FFS_READ_DESCRIPTORS; 2199 mutex_init(&ffs->mutex); 2200 spin_lock_init(&ffs->eps_lock); 2201 init_waitqueue_head(&ffs->ev.waitq); 2202 init_waitqueue_head(&ffs->wait); 2203 init_completion(&ffs->ep0req_completion); 2204 2205 /* XXX REVISIT need to update it in some places, or do we? */ 2206 ffs->ev.can_stall = 1; 2207 2208 return ffs; 2209 } 2210 2211 static void ffs_data_clear(struct ffs_data *ffs) 2212 { 2213 struct ffs_epfile *epfiles; 2214 unsigned long flags; 2215 2216 ffs_closed(ffs); 2217 2218 BUG_ON(ffs->gadget); 2219 2220 spin_lock_irqsave(&ffs->eps_lock, flags); 2221 epfiles = ffs->epfiles; 2222 ffs->epfiles = NULL; 2223 spin_unlock_irqrestore(&ffs->eps_lock, flags); 2224 2225 /* 2226 * potential race possible between ffs_func_eps_disable 2227 * & ffs_epfile_release therefore maintaining a local 2228 * copy of epfile will save us from use-after-free. 2229 */ 2230 if (epfiles) { 2231 ffs_epfiles_destroy(ffs->sb, epfiles, ffs->eps_count); 2232 ffs->epfiles = NULL; 2233 } 2234 2235 if (ffs->ffs_eventfd) { 2236 eventfd_ctx_put(ffs->ffs_eventfd); 2237 ffs->ffs_eventfd = NULL; 2238 } 2239 2240 kfree(ffs->raw_descs_data); 2241 kfree(ffs->raw_strings); 2242 kfree(ffs->stringtabs); 2243 } 2244 2245 static void ffs_data_reset(struct ffs_data *ffs) 2246 { 2247 ffs_data_clear(ffs); 2248 2249 spin_lock_irq(&ffs->eps_lock); 2250 ffs->raw_descs_data = NULL; 2251 ffs->raw_descs = NULL; 2252 ffs->raw_strings = NULL; 2253 ffs->stringtabs = NULL; 2254 2255 ffs->raw_descs_length = 0; 2256 ffs->fs_descs_count = 0; 2257 ffs->hs_descs_count = 0; 2258 ffs->ss_descs_count = 0; 2259 2260 ffs->strings_count = 0; 2261 ffs->interfaces_count = 0; 2262 ffs->eps_count = 0; 2263 2264 ffs->ev.count = 0; 2265 2266 ffs->state = FFS_READ_DESCRIPTORS; 2267 ffs->setup_state = FFS_NO_SETUP; 2268 ffs->flags = 0; 2269 2270 ffs->ms_os_descs_ext_prop_count = 0; 2271 ffs->ms_os_descs_ext_prop_name_len = 0; 2272 ffs->ms_os_descs_ext_prop_data_len = 0; 2273 spin_unlock_irq(&ffs->eps_lock); 2274 } 2275 2276 2277 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) 2278 { 2279 struct usb_gadget_strings **lang; 2280 int first_id; 2281 2282 if ((ffs->state != FFS_ACTIVE 2283 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags))) 2284 return -EBADFD; 2285 2286 first_id = usb_string_ids_n(cdev, ffs->strings_count); 2287 if (first_id < 0) 2288 return first_id; 2289 2290 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); 2291 if (!ffs->ep0req) 2292 return -ENOMEM; 2293 ffs->ep0req->complete = ffs_ep0_complete; 2294 ffs->ep0req->context = ffs; 2295 2296 lang = ffs->stringtabs; 2297 if (lang) { 2298 for (; *lang; ++lang) { 2299 struct usb_string *str = (*lang)->strings; 2300 int id = first_id; 2301 for (; str->s; ++id, ++str) 2302 str->id = id; 2303 } 2304 } 2305 2306 ffs->gadget = cdev->gadget; 2307 ffs_data_get(ffs); 2308 return 0; 2309 } 2310 2311 static void functionfs_unbind(struct ffs_data *ffs) 2312 { 2313 if (!WARN_ON(!ffs->gadget)) { 2314 /* dequeue before freeing ep0req */ 2315 usb_ep_dequeue(ffs->gadget->ep0, ffs->ep0req); 2316 mutex_lock(&ffs->mutex); 2317 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req); 2318 ffs->ep0req = NULL; 2319 ffs->gadget = NULL; 2320 clear_bit(FFS_FL_BOUND, &ffs->flags); 2321 mutex_unlock(&ffs->mutex); 2322 ffs_data_put(ffs); 2323 } 2324 } 2325 2326 static int ffs_epfiles_create(struct ffs_data *ffs) 2327 { 2328 struct ffs_epfile *epfile, *epfiles; 2329 unsigned i, count; 2330 int err; 2331 2332 count = ffs->eps_count; 2333 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL); 2334 if (!epfiles) 2335 return -ENOMEM; 2336 2337 epfile = epfiles; 2338 for (i = 1; i <= count; ++i, ++epfile) { 2339 epfile->ffs = ffs; 2340 mutex_init(&epfile->mutex); 2341 mutex_init(&epfile->dmabufs_mutex); 2342 INIT_LIST_HEAD(&epfile->dmabufs); 2343 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 2344 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]); 2345 else 2346 sprintf(epfile->name, "ep%u", i); 2347 err = ffs_sb_create_file(ffs->sb, epfile->name, 2348 epfile, &ffs_epfile_operations); 2349 if (err) { 2350 ffs_epfiles_destroy(ffs->sb, epfiles, i - 1); 2351 return err; 2352 } 2353 } 2354 2355 ffs->epfiles = epfiles; 2356 return 0; 2357 } 2358 2359 static void clear_one(struct dentry *dentry) 2360 { 2361 smp_store_release(&dentry->d_inode->i_private, NULL); 2362 } 2363 2364 static void ffs_epfiles_destroy(struct super_block *sb, 2365 struct ffs_epfile *epfiles, unsigned count) 2366 { 2367 struct ffs_epfile *epfile = epfiles; 2368 struct dentry *root = sb->s_root; 2369 2370 for (; count; --count, ++epfile) { 2371 BUG_ON(mutex_is_locked(&epfile->mutex)); 2372 simple_remove_by_name(root, epfile->name, clear_one); 2373 } 2374 2375 kfree(epfiles); 2376 } 2377 2378 static void ffs_func_eps_disable(struct ffs_function *func) 2379 { 2380 struct ffs_ep *ep; 2381 struct ffs_epfile *epfile; 2382 unsigned short count; 2383 unsigned long flags; 2384 2385 spin_lock_irqsave(&func->ffs->eps_lock, flags); 2386 count = func->ffs->eps_count; 2387 epfile = func->ffs->epfiles; 2388 ep = func->eps; 2389 while (count--) { 2390 /* pending requests get nuked */ 2391 if (ep->ep) 2392 usb_ep_disable(ep->ep); 2393 ++ep; 2394 2395 if (epfile) { 2396 epfile->ep = NULL; 2397 __ffs_epfile_read_buffer_free(epfile); 2398 ++epfile; 2399 } 2400 } 2401 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 2402 } 2403 2404 static int ffs_func_eps_enable(struct ffs_function *func) 2405 { 2406 struct ffs_data *ffs; 2407 struct ffs_ep *ep; 2408 struct ffs_epfile *epfile; 2409 unsigned short count; 2410 unsigned long flags; 2411 int ret = 0; 2412 2413 spin_lock_irqsave(&func->ffs->eps_lock, flags); 2414 ffs = func->ffs; 2415 ep = func->eps; 2416 epfile = ffs->epfiles; 2417 count = ffs->eps_count; 2418 if (!epfile) { 2419 ret = -ENOMEM; 2420 goto done; 2421 } 2422 2423 while (count--) { 2424 ep->ep->driver_data = ep; 2425 2426 ret = config_ep_by_speed(func->gadget, &func->function, ep->ep); 2427 if (ret) { 2428 pr_err("%s: config_ep_by_speed(%s) returned %d\n", 2429 __func__, ep->ep->name, ret); 2430 break; 2431 } 2432 2433 ret = usb_ep_enable(ep->ep); 2434 if (!ret) { 2435 epfile->ep = ep; 2436 epfile->in = usb_endpoint_dir_in(ep->ep->desc); 2437 epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc); 2438 } else { 2439 break; 2440 } 2441 2442 ++ep; 2443 ++epfile; 2444 } 2445 2446 wake_up_interruptible(&ffs->wait); 2447 done: 2448 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 2449 2450 return ret; 2451 } 2452 2453 2454 /* Parsing and building descriptors and strings *****************************/ 2455 2456 /* 2457 * This validates if data pointed by data is a valid USB descriptor as 2458 * well as record how many interfaces, endpoints and strings are 2459 * required by given configuration. Returns address after the 2460 * descriptor or NULL if data is invalid. 2461 */ 2462 2463 enum ffs_entity_type { 2464 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT 2465 }; 2466 2467 enum ffs_os_desc_type { 2468 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP 2469 }; 2470 2471 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity, 2472 u8 *valuep, 2473 struct usb_descriptor_header *desc, 2474 void *priv); 2475 2476 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity, 2477 struct usb_os_desc_header *h, void *data, 2478 unsigned len, void *priv); 2479 2480 static int __must_check ffs_do_single_desc(char *data, unsigned len, 2481 ffs_entity_callback entity, 2482 void *priv, int *current_class, int *current_subclass) 2483 { 2484 struct usb_descriptor_header *_ds = (void *)data; 2485 u8 length; 2486 int ret; 2487 2488 /* At least two bytes are required: length and type */ 2489 if (len < 2) { 2490 pr_vdebug("descriptor too short\n"); 2491 return -EINVAL; 2492 } 2493 2494 /* If we have at least as many bytes as the descriptor takes? */ 2495 length = _ds->bLength; 2496 if (len < length) { 2497 pr_vdebug("descriptor longer then available data\n"); 2498 return -EINVAL; 2499 } 2500 2501 #define __entity_check_INTERFACE(val) 1 2502 #define __entity_check_STRING(val) (val) 2503 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK) 2504 #define __entity(type, val) do { \ 2505 pr_vdebug("entity " #type "(%02x)\n", (val)); \ 2506 if (!__entity_check_ ##type(val)) { \ 2507 pr_vdebug("invalid entity's value\n"); \ 2508 return -EINVAL; \ 2509 } \ 2510 ret = entity(FFS_ ##type, &val, _ds, priv); \ 2511 if (ret < 0) { \ 2512 pr_debug("entity " #type "(%02x); ret = %d\n", \ 2513 (val), ret); \ 2514 return ret; \ 2515 } \ 2516 } while (0) 2517 2518 /* Parse descriptor depending on type. */ 2519 switch (_ds->bDescriptorType) { 2520 case USB_DT_DEVICE: 2521 case USB_DT_CONFIG: 2522 case USB_DT_STRING: 2523 case USB_DT_DEVICE_QUALIFIER: 2524 /* function can't have any of those */ 2525 pr_vdebug("descriptor reserved for gadget: %d\n", 2526 _ds->bDescriptorType); 2527 return -EINVAL; 2528 2529 case USB_DT_INTERFACE: { 2530 struct usb_interface_descriptor *ds = (void *)_ds; 2531 pr_vdebug("interface descriptor\n"); 2532 if (length != sizeof *ds) 2533 goto inv_length; 2534 2535 __entity(INTERFACE, ds->bInterfaceNumber); 2536 if (ds->iInterface) 2537 __entity(STRING, ds->iInterface); 2538 *current_class = ds->bInterfaceClass; 2539 *current_subclass = ds->bInterfaceSubClass; 2540 } 2541 break; 2542 2543 case USB_DT_ENDPOINT: { 2544 struct usb_endpoint_descriptor *ds = (void *)_ds; 2545 pr_vdebug("endpoint descriptor\n"); 2546 if (length != USB_DT_ENDPOINT_SIZE && 2547 length != USB_DT_ENDPOINT_AUDIO_SIZE) 2548 goto inv_length; 2549 __entity(ENDPOINT, ds->bEndpointAddress); 2550 } 2551 break; 2552 2553 case USB_TYPE_CLASS | 0x01: 2554 if (*current_class == USB_INTERFACE_CLASS_HID) { 2555 pr_vdebug("hid descriptor\n"); 2556 if (length != sizeof(struct hid_descriptor)) 2557 goto inv_length; 2558 break; 2559 } else if (*current_class == USB_INTERFACE_CLASS_CCID) { 2560 pr_vdebug("ccid descriptor\n"); 2561 if (length != sizeof(struct ccid_descriptor)) 2562 goto inv_length; 2563 break; 2564 } else if (*current_class == USB_CLASS_APP_SPEC && 2565 *current_subclass == USB_SUBCLASS_DFU) { 2566 pr_vdebug("dfu functional descriptor\n"); 2567 if (length != sizeof(struct usb_dfu_functional_descriptor)) 2568 goto inv_length; 2569 break; 2570 } else { 2571 pr_vdebug("unknown descriptor: %d for class %d\n", 2572 _ds->bDescriptorType, *current_class); 2573 return -EINVAL; 2574 } 2575 2576 case USB_DT_OTG: 2577 if (length != sizeof(struct usb_otg_descriptor)) 2578 goto inv_length; 2579 break; 2580 2581 case USB_DT_INTERFACE_ASSOCIATION: { 2582 struct usb_interface_assoc_descriptor *ds = (void *)_ds; 2583 pr_vdebug("interface association descriptor\n"); 2584 if (length != sizeof *ds) 2585 goto inv_length; 2586 if (ds->iFunction) 2587 __entity(STRING, ds->iFunction); 2588 } 2589 break; 2590 2591 case USB_DT_SS_ENDPOINT_COMP: 2592 pr_vdebug("EP SS companion descriptor\n"); 2593 if (length != sizeof(struct usb_ss_ep_comp_descriptor)) 2594 goto inv_length; 2595 break; 2596 2597 case USB_DT_OTHER_SPEED_CONFIG: 2598 case USB_DT_INTERFACE_POWER: 2599 case USB_DT_DEBUG: 2600 case USB_DT_SECURITY: 2601 case USB_DT_CS_RADIO_CONTROL: 2602 /* TODO */ 2603 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType); 2604 return -EINVAL; 2605 2606 default: 2607 /* We should never be here */ 2608 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType); 2609 return -EINVAL; 2610 2611 inv_length: 2612 pr_vdebug("invalid length: %d (descriptor %d)\n", 2613 _ds->bLength, _ds->bDescriptorType); 2614 return -EINVAL; 2615 } 2616 2617 #undef __entity 2618 #undef __entity_check_DESCRIPTOR 2619 #undef __entity_check_INTERFACE 2620 #undef __entity_check_STRING 2621 #undef __entity_check_ENDPOINT 2622 2623 return length; 2624 } 2625 2626 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, 2627 ffs_entity_callback entity, void *priv) 2628 { 2629 const unsigned _len = len; 2630 unsigned long num = 0; 2631 int current_class = -1; 2632 int current_subclass = -1; 2633 2634 for (;;) { 2635 int ret; 2636 2637 if (num == count) 2638 data = NULL; 2639 2640 /* Record "descriptor" entity */ 2641 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv); 2642 if (ret < 0) { 2643 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n", 2644 num, ret); 2645 return ret; 2646 } 2647 2648 if (!data) 2649 return _len - len; 2650 2651 ret = ffs_do_single_desc(data, len, entity, priv, 2652 ¤t_class, ¤t_subclass); 2653 if (ret < 0) { 2654 pr_debug("%s returns %d\n", __func__, ret); 2655 return ret; 2656 } 2657 2658 len -= ret; 2659 data += ret; 2660 ++num; 2661 } 2662 } 2663 2664 static int __ffs_data_do_entity(enum ffs_entity_type type, 2665 u8 *valuep, struct usb_descriptor_header *desc, 2666 void *priv) 2667 { 2668 struct ffs_desc_helper *helper = priv; 2669 struct usb_endpoint_descriptor *d; 2670 2671 switch (type) { 2672 case FFS_DESCRIPTOR: 2673 break; 2674 2675 case FFS_INTERFACE: 2676 /* 2677 * Interfaces are indexed from zero so if we 2678 * encountered interface "n" then there are at least 2679 * "n+1" interfaces. 2680 */ 2681 if (*valuep >= helper->interfaces_count) 2682 helper->interfaces_count = *valuep + 1; 2683 break; 2684 2685 case FFS_STRING: 2686 /* 2687 * Strings are indexed from 1 (0 is reserved 2688 * for languages list) 2689 */ 2690 if (*valuep > helper->ffs->strings_count) 2691 helper->ffs->strings_count = *valuep; 2692 break; 2693 2694 case FFS_ENDPOINT: 2695 d = (void *)desc; 2696 helper->eps_count++; 2697 if (helper->eps_count >= FFS_MAX_EPS_COUNT) 2698 return -EINVAL; 2699 /* Check if descriptors for any speed were already parsed */ 2700 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count) 2701 helper->ffs->eps_addrmap[helper->eps_count] = 2702 d->bEndpointAddress; 2703 else if (helper->ffs->eps_addrmap[helper->eps_count] != 2704 d->bEndpointAddress) 2705 return -EINVAL; 2706 break; 2707 } 2708 2709 return 0; 2710 } 2711 2712 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type, 2713 struct usb_os_desc_header *desc) 2714 { 2715 u16 bcd_version = le16_to_cpu(desc->bcdVersion); 2716 u16 w_index = le16_to_cpu(desc->wIndex); 2717 2718 if (bcd_version == 0x1) { 2719 pr_warn("bcdVersion must be 0x0100, stored in Little Endian order. " 2720 "Userspace driver should be fixed, accepting 0x0001 for compatibility.\n"); 2721 } else if (bcd_version != 0x100) { 2722 pr_vdebug("unsupported os descriptors version: 0x%x\n", 2723 bcd_version); 2724 return -EINVAL; 2725 } 2726 switch (w_index) { 2727 case 0x4: 2728 *next_type = FFS_OS_DESC_EXT_COMPAT; 2729 break; 2730 case 0x5: 2731 *next_type = FFS_OS_DESC_EXT_PROP; 2732 break; 2733 default: 2734 pr_vdebug("unsupported os descriptor type: %d", w_index); 2735 return -EINVAL; 2736 } 2737 2738 return sizeof(*desc); 2739 } 2740 2741 /* 2742 * Process all extended compatibility/extended property descriptors 2743 * of a feature descriptor 2744 */ 2745 static int __must_check ffs_do_single_os_desc(char *data, unsigned len, 2746 enum ffs_os_desc_type type, 2747 u16 feature_count, 2748 ffs_os_desc_callback entity, 2749 void *priv, 2750 struct usb_os_desc_header *h) 2751 { 2752 int ret; 2753 const unsigned _len = len; 2754 2755 /* loop over all ext compat/ext prop descriptors */ 2756 while (feature_count--) { 2757 ret = entity(type, h, data, len, priv); 2758 if (ret < 0) { 2759 pr_debug("bad OS descriptor, type: %d\n", type); 2760 return ret; 2761 } 2762 data += ret; 2763 len -= ret; 2764 } 2765 return _len - len; 2766 } 2767 2768 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */ 2769 static int __must_check ffs_do_os_descs(unsigned count, 2770 char *data, unsigned len, 2771 ffs_os_desc_callback entity, void *priv) 2772 { 2773 const unsigned _len = len; 2774 unsigned long num = 0; 2775 2776 for (num = 0; num < count; ++num) { 2777 int ret; 2778 enum ffs_os_desc_type type; 2779 u16 feature_count; 2780 struct usb_os_desc_header *desc = (void *)data; 2781 2782 if (len < sizeof(*desc)) 2783 return -EINVAL; 2784 2785 /* 2786 * Record "descriptor" entity. 2787 * Process dwLength, bcdVersion, wIndex, get b/wCount. 2788 * Move the data pointer to the beginning of extended 2789 * compatibilities proper or extended properties proper 2790 * portions of the data 2791 */ 2792 if (le32_to_cpu(desc->dwLength) > len) 2793 return -EINVAL; 2794 2795 ret = __ffs_do_os_desc_header(&type, desc); 2796 if (ret < 0) { 2797 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n", 2798 num, ret); 2799 return ret; 2800 } 2801 /* 2802 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??" 2803 */ 2804 feature_count = le16_to_cpu(desc->wCount); 2805 if (type == FFS_OS_DESC_EXT_COMPAT && 2806 (feature_count > 255 || desc->Reserved)) 2807 return -EINVAL; 2808 len -= ret; 2809 data += ret; 2810 2811 /* 2812 * Process all function/property descriptors 2813 * of this Feature Descriptor 2814 */ 2815 ret = ffs_do_single_os_desc(data, len, type, 2816 feature_count, entity, priv, desc); 2817 if (ret < 0) { 2818 pr_debug("%s returns %d\n", __func__, ret); 2819 return ret; 2820 } 2821 2822 len -= ret; 2823 data += ret; 2824 } 2825 return _len - len; 2826 } 2827 2828 /* 2829 * Validate contents of the buffer from userspace related to OS descriptors. 2830 */ 2831 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type, 2832 struct usb_os_desc_header *h, void *data, 2833 unsigned len, void *priv) 2834 { 2835 struct ffs_data *ffs = priv; 2836 u8 length; 2837 2838 switch (type) { 2839 case FFS_OS_DESC_EXT_COMPAT: { 2840 struct usb_ext_compat_desc *d = data; 2841 int i; 2842 2843 if (len < sizeof(*d) || 2844 d->bFirstInterfaceNumber >= ffs->interfaces_count) 2845 return -EINVAL; 2846 if (d->Reserved1 != 1) { 2847 /* 2848 * According to the spec, Reserved1 must be set to 1 2849 * but older kernels incorrectly rejected non-zero 2850 * values. We fix it here to avoid returning EINVAL 2851 * in response to values we used to accept. 2852 */ 2853 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n"); 2854 d->Reserved1 = 1; 2855 } 2856 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i) 2857 if (d->Reserved2[i]) 2858 return -EINVAL; 2859 2860 length = sizeof(struct usb_ext_compat_desc); 2861 } 2862 break; 2863 case FFS_OS_DESC_EXT_PROP: { 2864 struct usb_ext_prop_desc *d = data; 2865 u32 type, pdl; 2866 u16 pnl; 2867 2868 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count) 2869 return -EINVAL; 2870 length = le32_to_cpu(d->dwSize); 2871 if (len < length) 2872 return -EINVAL; 2873 type = le32_to_cpu(d->dwPropertyDataType); 2874 if (type < USB_EXT_PROP_UNICODE || 2875 type > USB_EXT_PROP_UNICODE_MULTI) { 2876 pr_vdebug("unsupported os descriptor property type: %d", 2877 type); 2878 return -EINVAL; 2879 } 2880 pnl = le16_to_cpu(d->wPropertyNameLength); 2881 if (length < 14 + pnl) { 2882 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n", 2883 length, pnl, type); 2884 return -EINVAL; 2885 } 2886 pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl)); 2887 if (length != 14 + pnl + pdl) { 2888 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n", 2889 length, pnl, pdl, type); 2890 return -EINVAL; 2891 } 2892 ++ffs->ms_os_descs_ext_prop_count; 2893 /* property name reported to the host as "WCHAR"s */ 2894 ffs->ms_os_descs_ext_prop_name_len += pnl * 2; 2895 ffs->ms_os_descs_ext_prop_data_len += pdl; 2896 } 2897 break; 2898 default: 2899 pr_vdebug("unknown descriptor: %d\n", type); 2900 return -EINVAL; 2901 } 2902 return length; 2903 } 2904 2905 static int __ffs_data_got_descs(struct ffs_data *ffs, 2906 char *const _data, size_t len) 2907 { 2908 char *data = _data, *raw_descs; 2909 unsigned os_descs_count = 0, counts[3], flags; 2910 int ret = -EINVAL, i; 2911 struct ffs_desc_helper helper; 2912 2913 if (get_unaligned_le32(data + 4) != len) 2914 goto error; 2915 2916 switch (get_unaligned_le32(data)) { 2917 case FUNCTIONFS_DESCRIPTORS_MAGIC: 2918 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC; 2919 data += 8; 2920 len -= 8; 2921 break; 2922 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2: 2923 flags = get_unaligned_le32(data + 8); 2924 ffs->user_flags = flags; 2925 if (flags & ~(FUNCTIONFS_HAS_FS_DESC | 2926 FUNCTIONFS_HAS_HS_DESC | 2927 FUNCTIONFS_HAS_SS_DESC | 2928 FUNCTIONFS_HAS_MS_OS_DESC | 2929 FUNCTIONFS_VIRTUAL_ADDR | 2930 FUNCTIONFS_EVENTFD | 2931 FUNCTIONFS_ALL_CTRL_RECIP | 2932 FUNCTIONFS_CONFIG0_SETUP)) { 2933 ret = -ENOSYS; 2934 goto error; 2935 } 2936 data += 12; 2937 len -= 12; 2938 break; 2939 default: 2940 goto error; 2941 } 2942 2943 if (flags & FUNCTIONFS_EVENTFD) { 2944 if (len < 4) 2945 goto error; 2946 ffs->ffs_eventfd = 2947 eventfd_ctx_fdget((int)get_unaligned_le32(data)); 2948 if (IS_ERR(ffs->ffs_eventfd)) { 2949 ret = PTR_ERR(ffs->ffs_eventfd); 2950 ffs->ffs_eventfd = NULL; 2951 goto error; 2952 } 2953 data += 4; 2954 len -= 4; 2955 } 2956 2957 /* Read fs_count, hs_count and ss_count (if present) */ 2958 for (i = 0; i < 3; ++i) { 2959 if (!(flags & (1 << i))) { 2960 counts[i] = 0; 2961 } else if (len < 4) { 2962 goto error; 2963 } else { 2964 counts[i] = get_unaligned_le32(data); 2965 data += 4; 2966 len -= 4; 2967 } 2968 } 2969 if (flags & (1 << i)) { 2970 if (len < 4) { 2971 goto error; 2972 } 2973 os_descs_count = get_unaligned_le32(data); 2974 data += 4; 2975 len -= 4; 2976 } 2977 2978 /* Read descriptors */ 2979 raw_descs = data; 2980 helper.ffs = ffs; 2981 for (i = 0; i < 3; ++i) { 2982 if (!counts[i]) 2983 continue; 2984 helper.interfaces_count = 0; 2985 helper.eps_count = 0; 2986 ret = ffs_do_descs(counts[i], data, len, 2987 __ffs_data_do_entity, &helper); 2988 if (ret < 0) 2989 goto error; 2990 if (!ffs->eps_count && !ffs->interfaces_count) { 2991 ffs->eps_count = helper.eps_count; 2992 ffs->interfaces_count = helper.interfaces_count; 2993 } else { 2994 if (ffs->eps_count != helper.eps_count) { 2995 ret = -EINVAL; 2996 goto error; 2997 } 2998 if (ffs->interfaces_count != helper.interfaces_count) { 2999 ret = -EINVAL; 3000 goto error; 3001 } 3002 } 3003 data += ret; 3004 len -= ret; 3005 } 3006 if (os_descs_count) { 3007 ret = ffs_do_os_descs(os_descs_count, data, len, 3008 __ffs_data_do_os_desc, ffs); 3009 if (ret < 0) 3010 goto error; 3011 data += ret; 3012 len -= ret; 3013 } 3014 3015 if (raw_descs == data || len) { 3016 ret = -EINVAL; 3017 goto error; 3018 } 3019 3020 ffs->raw_descs_data = _data; 3021 ffs->raw_descs = raw_descs; 3022 ffs->raw_descs_length = data - raw_descs; 3023 ffs->fs_descs_count = counts[0]; 3024 ffs->hs_descs_count = counts[1]; 3025 ffs->ss_descs_count = counts[2]; 3026 ffs->ms_os_descs_count = os_descs_count; 3027 3028 return 0; 3029 3030 error: 3031 kfree(_data); 3032 return ret; 3033 } 3034 3035 static int __ffs_data_got_strings(struct ffs_data *ffs, 3036 char *const _data, size_t len) 3037 { 3038 u32 str_count, needed_count, lang_count; 3039 struct usb_gadget_strings **stringtabs, *t; 3040 const char *data = _data; 3041 struct usb_string *s; 3042 3043 if (len < 16 || 3044 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC || 3045 get_unaligned_le32(data + 4) != len) 3046 goto error; 3047 str_count = get_unaligned_le32(data + 8); 3048 lang_count = get_unaligned_le32(data + 12); 3049 3050 /* if one is zero the other must be zero */ 3051 if (!str_count != !lang_count) 3052 goto error; 3053 3054 /* Do we have at least as many strings as descriptors need? */ 3055 needed_count = ffs->strings_count; 3056 if (str_count < needed_count) 3057 goto error; 3058 3059 /* 3060 * If we don't need any strings just return and free all 3061 * memory. 3062 */ 3063 if (!needed_count) { 3064 kfree(_data); 3065 return 0; 3066 } 3067 3068 /* Allocate everything in one chunk so there's less maintenance. */ 3069 { 3070 unsigned i = 0; 3071 vla_group(d); 3072 vla_item(d, struct usb_gadget_strings *, stringtabs, 3073 size_add(lang_count, 1)); 3074 vla_item(d, struct usb_gadget_strings, stringtab, lang_count); 3075 vla_item(d, struct usb_string, strings, 3076 size_mul(lang_count, (needed_count + 1))); 3077 3078 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL); 3079 3080 if (!vlabuf) { 3081 kfree(_data); 3082 return -ENOMEM; 3083 } 3084 3085 /* Initialize the VLA pointers */ 3086 stringtabs = vla_ptr(vlabuf, d, stringtabs); 3087 t = vla_ptr(vlabuf, d, stringtab); 3088 i = lang_count; 3089 do { 3090 *stringtabs++ = t++; 3091 } while (--i); 3092 *stringtabs = NULL; 3093 3094 /* stringtabs = vlabuf = d_stringtabs for later kfree */ 3095 stringtabs = vla_ptr(vlabuf, d, stringtabs); 3096 t = vla_ptr(vlabuf, d, stringtab); 3097 s = vla_ptr(vlabuf, d, strings); 3098 } 3099 3100 /* For each language */ 3101 data += 16; 3102 len -= 16; 3103 3104 do { /* lang_count > 0 so we can use do-while */ 3105 unsigned needed = needed_count; 3106 u32 str_per_lang = str_count; 3107 3108 if (len < 3) 3109 goto error_free; 3110 t->language = get_unaligned_le16(data); 3111 t->strings = s; 3112 ++t; 3113 3114 data += 2; 3115 len -= 2; 3116 3117 /* For each string */ 3118 do { /* str_count > 0 so we can use do-while */ 3119 size_t length = strnlen(data, len); 3120 3121 if (length == len) 3122 goto error_free; 3123 3124 /* 3125 * User may provide more strings then we need, 3126 * if that's the case we simply ignore the 3127 * rest 3128 */ 3129 if (needed) { 3130 /* 3131 * s->id will be set while adding 3132 * function to configuration so for 3133 * now just leave garbage here. 3134 */ 3135 s->s = data; 3136 --needed; 3137 ++s; 3138 } 3139 3140 data += length + 1; 3141 len -= length + 1; 3142 } while (--str_per_lang); 3143 3144 s->id = 0; /* terminator */ 3145 s->s = NULL; 3146 ++s; 3147 3148 } while (--lang_count); 3149 3150 /* Some garbage left? */ 3151 if (len) 3152 goto error_free; 3153 3154 /* Done! */ 3155 ffs->stringtabs = stringtabs; 3156 ffs->raw_strings = _data; 3157 3158 return 0; 3159 3160 error_free: 3161 kfree(stringtabs); 3162 error: 3163 kfree(_data); 3164 return -EINVAL; 3165 } 3166 3167 3168 /* Events handling and management *******************************************/ 3169 3170 static void __ffs_event_add(struct ffs_data *ffs, 3171 enum usb_functionfs_event_type type) 3172 { 3173 enum usb_functionfs_event_type rem_type1, rem_type2 = type; 3174 int neg = 0; 3175 3176 /* 3177 * Abort any unhandled setup 3178 * 3179 * We do not need to worry about some cmpxchg() changing value 3180 * of ffs->setup_state without holding the lock because when 3181 * state is FFS_SETUP_PENDING cmpxchg() in several places in 3182 * the source does nothing. 3183 */ 3184 if (ffs->setup_state == FFS_SETUP_PENDING) 3185 ffs->setup_state = FFS_SETUP_CANCELLED; 3186 3187 /* 3188 * Logic of this function guarantees that there are at most four pending 3189 * evens on ffs->ev.types queue. This is important because the queue 3190 * has space for four elements only and __ffs_ep0_read_events function 3191 * depends on that limit as well. If more event types are added, those 3192 * limits have to be revisited or guaranteed to still hold. 3193 */ 3194 switch (type) { 3195 case FUNCTIONFS_RESUME: 3196 rem_type2 = FUNCTIONFS_SUSPEND; 3197 fallthrough; 3198 case FUNCTIONFS_SUSPEND: 3199 case FUNCTIONFS_SETUP: 3200 rem_type1 = type; 3201 /* Discard all similar events */ 3202 break; 3203 3204 case FUNCTIONFS_BIND: 3205 case FUNCTIONFS_UNBIND: 3206 case FUNCTIONFS_DISABLE: 3207 case FUNCTIONFS_ENABLE: 3208 /* Discard everything other then power management. */ 3209 rem_type1 = FUNCTIONFS_SUSPEND; 3210 rem_type2 = FUNCTIONFS_RESUME; 3211 neg = 1; 3212 break; 3213 3214 default: 3215 WARN(1, "%d: unknown event, this should not happen\n", type); 3216 return; 3217 } 3218 3219 { 3220 u8 *ev = ffs->ev.types, *out = ev; 3221 unsigned n = ffs->ev.count; 3222 for (; n; --n, ++ev) 3223 if ((*ev == rem_type1 || *ev == rem_type2) == neg) 3224 *out++ = *ev; 3225 else 3226 pr_vdebug("purging event %d\n", *ev); 3227 ffs->ev.count = out - ffs->ev.types; 3228 } 3229 3230 pr_vdebug("adding event %d\n", type); 3231 ffs->ev.types[ffs->ev.count++] = type; 3232 wake_up_locked(&ffs->ev.waitq); 3233 if (ffs->ffs_eventfd) 3234 eventfd_signal(ffs->ffs_eventfd); 3235 } 3236 3237 static void ffs_event_add(struct ffs_data *ffs, 3238 enum usb_functionfs_event_type type) 3239 { 3240 unsigned long flags; 3241 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 3242 __ffs_event_add(ffs, type); 3243 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 3244 } 3245 3246 /* Bind/unbind USB function hooks *******************************************/ 3247 3248 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address) 3249 { 3250 int i; 3251 3252 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i) 3253 if (ffs->eps_addrmap[i] == endpoint_address) 3254 return i; 3255 return -ENOENT; 3256 } 3257 3258 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep, 3259 struct usb_descriptor_header *desc, 3260 void *priv) 3261 { 3262 struct usb_endpoint_descriptor *ds = (void *)desc; 3263 struct ffs_function *func = priv; 3264 struct ffs_ep *ffs_ep; 3265 unsigned ep_desc_id; 3266 int idx; 3267 static const char *speed_names[] = { "full", "high", "super" }; 3268 3269 if (type != FFS_DESCRIPTOR) 3270 return 0; 3271 3272 /* 3273 * If ss_descriptors is not NULL, we are reading super speed 3274 * descriptors; if hs_descriptors is not NULL, we are reading high 3275 * speed descriptors; otherwise, we are reading full speed 3276 * descriptors. 3277 */ 3278 if (func->function.ss_descriptors) { 3279 ep_desc_id = 2; 3280 func->function.ss_descriptors[(long)valuep] = desc; 3281 } else if (func->function.hs_descriptors) { 3282 ep_desc_id = 1; 3283 func->function.hs_descriptors[(long)valuep] = desc; 3284 } else { 3285 ep_desc_id = 0; 3286 func->function.fs_descriptors[(long)valuep] = desc; 3287 } 3288 3289 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) 3290 return 0; 3291 3292 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1; 3293 if (idx < 0) 3294 return idx; 3295 3296 ffs_ep = func->eps + idx; 3297 3298 if (ffs_ep->descs[ep_desc_id]) { 3299 pr_err("two %sspeed descriptors for EP %d\n", 3300 speed_names[ep_desc_id], 3301 usb_endpoint_num(ds)); 3302 return -EINVAL; 3303 } 3304 ffs_ep->descs[ep_desc_id] = ds; 3305 3306 ffs_dump_mem(": Original ep desc", ds, ds->bLength); 3307 if (ffs_ep->ep) { 3308 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress; 3309 if (!ds->wMaxPacketSize) 3310 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize; 3311 } else { 3312 struct usb_request *req; 3313 struct usb_ep *ep; 3314 u8 bEndpointAddress; 3315 u16 wMaxPacketSize; 3316 3317 /* 3318 * We back up bEndpointAddress because autoconfig overwrites 3319 * it with physical endpoint address. 3320 */ 3321 bEndpointAddress = ds->bEndpointAddress; 3322 /* 3323 * We back up wMaxPacketSize because autoconfig treats 3324 * endpoint descriptors as if they were full speed. 3325 */ 3326 wMaxPacketSize = ds->wMaxPacketSize; 3327 pr_vdebug("autoconfig\n"); 3328 ep = usb_ep_autoconfig(func->gadget, ds); 3329 if (!ep) 3330 return -ENOTSUPP; 3331 ep->driver_data = func->eps + idx; 3332 3333 req = usb_ep_alloc_request(ep, GFP_KERNEL); 3334 if (!req) 3335 return -ENOMEM; 3336 3337 ffs_ep->ep = ep; 3338 ffs_ep->req = req; 3339 func->eps_revmap[ds->bEndpointAddress & 3340 USB_ENDPOINT_NUMBER_MASK] = idx + 1; 3341 /* 3342 * If we use virtual address mapping, we restore 3343 * original bEndpointAddress value. 3344 */ 3345 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 3346 ds->bEndpointAddress = bEndpointAddress; 3347 /* 3348 * Restore wMaxPacketSize which was potentially 3349 * overwritten by autoconfig. 3350 */ 3351 ds->wMaxPacketSize = wMaxPacketSize; 3352 } 3353 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength); 3354 3355 return 0; 3356 } 3357 3358 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep, 3359 struct usb_descriptor_header *desc, 3360 void *priv) 3361 { 3362 struct ffs_function *func = priv; 3363 unsigned idx; 3364 u8 newValue; 3365 3366 switch (type) { 3367 default: 3368 case FFS_DESCRIPTOR: 3369 /* Handled in previous pass by __ffs_func_bind_do_descs() */ 3370 return 0; 3371 3372 case FFS_INTERFACE: 3373 idx = *valuep; 3374 if (func->interfaces_nums[idx] < 0) { 3375 int id = usb_interface_id(func->conf, &func->function); 3376 if (id < 0) 3377 return id; 3378 func->interfaces_nums[idx] = id; 3379 } 3380 newValue = func->interfaces_nums[idx]; 3381 break; 3382 3383 case FFS_STRING: 3384 /* String' IDs are allocated when fsf_data is bound to cdev */ 3385 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id; 3386 break; 3387 3388 case FFS_ENDPOINT: 3389 /* 3390 * USB_DT_ENDPOINT are handled in 3391 * __ffs_func_bind_do_descs(). 3392 */ 3393 if (desc->bDescriptorType == USB_DT_ENDPOINT) 3394 return 0; 3395 3396 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1; 3397 if (!func->eps[idx].ep) 3398 return -EINVAL; 3399 3400 { 3401 struct usb_endpoint_descriptor **descs; 3402 descs = func->eps[idx].descs; 3403 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress; 3404 } 3405 break; 3406 } 3407 3408 pr_vdebug("%02x -> %02x\n", *valuep, newValue); 3409 *valuep = newValue; 3410 return 0; 3411 } 3412 3413 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type, 3414 struct usb_os_desc_header *h, void *data, 3415 unsigned len, void *priv) 3416 { 3417 struct ffs_function *func = priv; 3418 u8 length = 0; 3419 3420 switch (type) { 3421 case FFS_OS_DESC_EXT_COMPAT: { 3422 struct usb_ext_compat_desc *desc = data; 3423 struct usb_os_desc_table *t; 3424 3425 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber]; 3426 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber]; 3427 memcpy(t->os_desc->ext_compat_id, &desc->IDs, 3428 sizeof_field(struct usb_ext_compat_desc, IDs)); 3429 length = sizeof(*desc); 3430 } 3431 break; 3432 case FFS_OS_DESC_EXT_PROP: { 3433 struct usb_ext_prop_desc *desc = data; 3434 struct usb_os_desc_table *t; 3435 struct usb_os_desc_ext_prop *ext_prop; 3436 char *ext_prop_name; 3437 char *ext_prop_data; 3438 3439 t = &func->function.os_desc_table[h->interface]; 3440 t->if_id = func->interfaces_nums[h->interface]; 3441 3442 ext_prop = func->ffs->ms_os_descs_ext_prop_avail; 3443 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop); 3444 3445 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType); 3446 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength); 3447 ext_prop->data_len = le32_to_cpu(*(__le32 *) 3448 usb_ext_prop_data_len_ptr(data, ext_prop->name_len)); 3449 length = ext_prop->name_len + ext_prop->data_len + 14; 3450 3451 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail; 3452 func->ffs->ms_os_descs_ext_prop_name_avail += 3453 ext_prop->name_len; 3454 3455 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail; 3456 func->ffs->ms_os_descs_ext_prop_data_avail += 3457 ext_prop->data_len; 3458 memcpy(ext_prop_data, 3459 usb_ext_prop_data_ptr(data, ext_prop->name_len), 3460 ext_prop->data_len); 3461 /* unicode data reported to the host as "WCHAR"s */ 3462 switch (ext_prop->type) { 3463 case USB_EXT_PROP_UNICODE: 3464 case USB_EXT_PROP_UNICODE_ENV: 3465 case USB_EXT_PROP_UNICODE_LINK: 3466 case USB_EXT_PROP_UNICODE_MULTI: 3467 ext_prop->data_len *= 2; 3468 break; 3469 } 3470 ext_prop->data = ext_prop_data; 3471 3472 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data), 3473 ext_prop->name_len); 3474 /* property name reported to the host as "WCHAR"s */ 3475 ext_prop->name_len *= 2; 3476 ext_prop->name = ext_prop_name; 3477 3478 t->os_desc->ext_prop_len += 3479 ext_prop->name_len + ext_prop->data_len + 14; 3480 ++t->os_desc->ext_prop_count; 3481 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop); 3482 } 3483 break; 3484 default: 3485 pr_vdebug("unknown descriptor: %d\n", type); 3486 } 3487 3488 return length; 3489 } 3490 3491 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, 3492 struct usb_configuration *c) 3493 { 3494 struct ffs_function *func = ffs_func_from_usb(f); 3495 struct f_fs_opts *ffs_opts = 3496 container_of(f->fi, struct f_fs_opts, func_inst); 3497 struct ffs_data *ffs_data; 3498 int ret; 3499 3500 /* 3501 * Legacy gadget triggers binding in functionfs_ready_callback, 3502 * which already uses locking; taking the same lock here would 3503 * cause a deadlock. 3504 * 3505 * Configfs-enabled gadgets however do need ffs_dev_lock. 3506 */ 3507 if (!ffs_opts->no_configfs) 3508 ffs_dev_lock(); 3509 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV; 3510 ffs_data = ffs_opts->dev->ffs_data; 3511 if (!ffs_opts->no_configfs) 3512 ffs_dev_unlock(); 3513 if (ret) 3514 return ERR_PTR(ret); 3515 3516 func->ffs = ffs_data; 3517 func->conf = c; 3518 func->gadget = c->cdev->gadget; 3519 3520 /* 3521 * in drivers/usb/gadget/configfs.c:configfs_composite_bind() 3522 * configurations are bound in sequence with list_for_each_entry, 3523 * in each configuration its functions are bound in sequence 3524 * with list_for_each_entry, so we assume no race condition 3525 * with regard to ffs_opts->bound access 3526 */ 3527 if (!ffs_opts->refcnt) { 3528 ret = functionfs_bind(func->ffs, c->cdev); 3529 if (ret) 3530 return ERR_PTR(ret); 3531 } 3532 ffs_opts->refcnt++; 3533 func->function.strings = func->ffs->stringtabs; 3534 3535 return ffs_opts; 3536 } 3537 3538 static int _ffs_func_bind(struct usb_configuration *c, 3539 struct usb_function *f) 3540 { 3541 struct ffs_function *func = ffs_func_from_usb(f); 3542 struct ffs_data *ffs = func->ffs; 3543 3544 const int full = !!func->ffs->fs_descs_count; 3545 const int high = !!func->ffs->hs_descs_count; 3546 const int super = !!func->ffs->ss_descs_count; 3547 3548 int fs_len, hs_len, ss_len, ret, i; 3549 struct ffs_ep *eps_ptr; 3550 3551 /* Make it a single chunk, less management later on */ 3552 vla_group(d); 3553 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count); 3554 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs, 3555 full ? ffs->fs_descs_count + 1 : 0); 3556 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs, 3557 high ? ffs->hs_descs_count + 1 : 0); 3558 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs, 3559 super ? ffs->ss_descs_count + 1 : 0); 3560 vla_item_with_sz(d, short, inums, ffs->interfaces_count); 3561 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table, 3562 c->cdev->use_os_string ? ffs->interfaces_count : 0); 3563 vla_item_with_sz(d, char[16], ext_compat, 3564 c->cdev->use_os_string ? ffs->interfaces_count : 0); 3565 vla_item_with_sz(d, struct usb_os_desc, os_desc, 3566 c->cdev->use_os_string ? ffs->interfaces_count : 0); 3567 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop, 3568 ffs->ms_os_descs_ext_prop_count); 3569 vla_item_with_sz(d, char, ext_prop_name, 3570 ffs->ms_os_descs_ext_prop_name_len); 3571 vla_item_with_sz(d, char, ext_prop_data, 3572 ffs->ms_os_descs_ext_prop_data_len); 3573 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length); 3574 char *vlabuf; 3575 3576 /* Has descriptors only for speeds gadget does not support */ 3577 if (!(full | high | super)) 3578 return -ENOTSUPP; 3579 3580 /* Allocate a single chunk, less management later on */ 3581 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL); 3582 if (!vlabuf) 3583 return -ENOMEM; 3584 3585 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop); 3586 ffs->ms_os_descs_ext_prop_name_avail = 3587 vla_ptr(vlabuf, d, ext_prop_name); 3588 ffs->ms_os_descs_ext_prop_data_avail = 3589 vla_ptr(vlabuf, d, ext_prop_data); 3590 3591 /* Copy descriptors */ 3592 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs, 3593 ffs->raw_descs_length); 3594 3595 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz); 3596 eps_ptr = vla_ptr(vlabuf, d, eps); 3597 for (i = 0; i < ffs->eps_count; i++) 3598 eps_ptr[i].num = -1; 3599 3600 /* Save pointers 3601 * d_eps == vlabuf, func->eps used to kfree vlabuf later 3602 */ 3603 func->eps = vla_ptr(vlabuf, d, eps); 3604 func->interfaces_nums = vla_ptr(vlabuf, d, inums); 3605 3606 /* 3607 * Go through all the endpoint descriptors and allocate 3608 * endpoints first, so that later we can rewrite the endpoint 3609 * numbers without worrying that it may be described later on. 3610 */ 3611 if (full) { 3612 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs); 3613 fs_len = ffs_do_descs(ffs->fs_descs_count, 3614 vla_ptr(vlabuf, d, raw_descs), 3615 d_raw_descs__sz, 3616 __ffs_func_bind_do_descs, func); 3617 if (fs_len < 0) { 3618 ret = fs_len; 3619 goto error; 3620 } 3621 } else { 3622 fs_len = 0; 3623 } 3624 3625 if (high) { 3626 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs); 3627 hs_len = ffs_do_descs(ffs->hs_descs_count, 3628 vla_ptr(vlabuf, d, raw_descs) + fs_len, 3629 d_raw_descs__sz - fs_len, 3630 __ffs_func_bind_do_descs, func); 3631 if (hs_len < 0) { 3632 ret = hs_len; 3633 goto error; 3634 } 3635 } else { 3636 hs_len = 0; 3637 } 3638 3639 if (super) { 3640 func->function.ss_descriptors = func->function.ssp_descriptors = 3641 vla_ptr(vlabuf, d, ss_descs); 3642 ss_len = ffs_do_descs(ffs->ss_descs_count, 3643 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len, 3644 d_raw_descs__sz - fs_len - hs_len, 3645 __ffs_func_bind_do_descs, func); 3646 if (ss_len < 0) { 3647 ret = ss_len; 3648 goto error; 3649 } 3650 } else { 3651 ss_len = 0; 3652 } 3653 3654 /* 3655 * Now handle interface numbers allocation and interface and 3656 * endpoint numbers rewriting. We can do that in one go 3657 * now. 3658 */ 3659 ret = ffs_do_descs(ffs->fs_descs_count + 3660 (high ? ffs->hs_descs_count : 0) + 3661 (super ? ffs->ss_descs_count : 0), 3662 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz, 3663 __ffs_func_bind_do_nums, func); 3664 if (ret < 0) 3665 goto error; 3666 3667 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table); 3668 if (c->cdev->use_os_string) { 3669 for (i = 0; i < ffs->interfaces_count; ++i) { 3670 struct usb_os_desc *desc; 3671 3672 desc = func->function.os_desc_table[i].os_desc = 3673 vla_ptr(vlabuf, d, os_desc) + 3674 i * sizeof(struct usb_os_desc); 3675 desc->ext_compat_id = 3676 vla_ptr(vlabuf, d, ext_compat) + i * 16; 3677 INIT_LIST_HEAD(&desc->ext_prop); 3678 } 3679 ret = ffs_do_os_descs(ffs->ms_os_descs_count, 3680 vla_ptr(vlabuf, d, raw_descs) + 3681 fs_len + hs_len + ss_len, 3682 d_raw_descs__sz - fs_len - hs_len - 3683 ss_len, 3684 __ffs_func_bind_do_os_desc, func); 3685 if (ret < 0) 3686 goto error; 3687 } 3688 func->function.os_desc_n = 3689 c->cdev->use_os_string ? ffs->interfaces_count : 0; 3690 3691 /* And we're done */ 3692 ffs_event_add(ffs, FUNCTIONFS_BIND); 3693 return 0; 3694 3695 error: 3696 /* XXX Do we need to release all claimed endpoints here? */ 3697 return ret; 3698 } 3699 3700 static int ffs_func_bind(struct usb_configuration *c, 3701 struct usb_function *f) 3702 { 3703 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c); 3704 struct ffs_function *func = ffs_func_from_usb(f); 3705 int ret; 3706 3707 if (IS_ERR(ffs_opts)) 3708 return PTR_ERR(ffs_opts); 3709 3710 ret = _ffs_func_bind(c, f); 3711 if (ret && !--ffs_opts->refcnt) 3712 functionfs_unbind(func->ffs); 3713 3714 return ret; 3715 } 3716 3717 3718 /* Other USB function hooks *************************************************/ 3719 3720 static void ffs_reset_work(struct work_struct *work) 3721 { 3722 struct ffs_data *ffs = container_of(work, 3723 struct ffs_data, reset_work); 3724 ffs_data_reset(ffs); 3725 } 3726 3727 static int ffs_func_get_alt(struct usb_function *f, 3728 unsigned int interface) 3729 { 3730 struct ffs_function *func = ffs_func_from_usb(f); 3731 int intf = ffs_func_revmap_intf(func, interface); 3732 3733 return (intf < 0) ? intf : func->cur_alt[interface]; 3734 } 3735 3736 static int ffs_func_set_alt(struct usb_function *f, 3737 unsigned interface, unsigned alt) 3738 { 3739 struct ffs_function *func = ffs_func_from_usb(f); 3740 struct ffs_data *ffs = func->ffs; 3741 unsigned long flags; 3742 int ret = 0, intf; 3743 3744 if (alt > MAX_ALT_SETTINGS) 3745 return -EINVAL; 3746 3747 intf = ffs_func_revmap_intf(func, interface); 3748 if (intf < 0) 3749 return intf; 3750 3751 if (ffs->func) 3752 ffs_func_eps_disable(ffs->func); 3753 3754 spin_lock_irqsave(&ffs->eps_lock, flags); 3755 if (ffs->state == FFS_DEACTIVATED) { 3756 ffs->state = FFS_CLOSING; 3757 spin_unlock_irqrestore(&ffs->eps_lock, flags); 3758 INIT_WORK(&ffs->reset_work, ffs_reset_work); 3759 schedule_work(&ffs->reset_work); 3760 return -ENODEV; 3761 } 3762 spin_unlock_irqrestore(&ffs->eps_lock, flags); 3763 3764 if (ffs->state != FFS_ACTIVE) 3765 return -ENODEV; 3766 3767 ffs->func = func; 3768 ret = ffs_func_eps_enable(func); 3769 if (ret >= 0) { 3770 ffs_event_add(ffs, FUNCTIONFS_ENABLE); 3771 func->cur_alt[interface] = alt; 3772 } 3773 return ret; 3774 } 3775 3776 static void ffs_func_disable(struct usb_function *f) 3777 { 3778 struct ffs_function *func = ffs_func_from_usb(f); 3779 struct ffs_data *ffs = func->ffs; 3780 unsigned long flags; 3781 3782 if (ffs->func) 3783 ffs_func_eps_disable(ffs->func); 3784 3785 spin_lock_irqsave(&ffs->eps_lock, flags); 3786 if (ffs->state == FFS_DEACTIVATED) { 3787 ffs->state = FFS_CLOSING; 3788 spin_unlock_irqrestore(&ffs->eps_lock, flags); 3789 INIT_WORK(&ffs->reset_work, ffs_reset_work); 3790 schedule_work(&ffs->reset_work); 3791 return; 3792 } 3793 spin_unlock_irqrestore(&ffs->eps_lock, flags); 3794 3795 if (ffs->state == FFS_ACTIVE) { 3796 ffs->func = NULL; 3797 ffs_event_add(ffs, FUNCTIONFS_DISABLE); 3798 } 3799 } 3800 3801 static int ffs_func_setup(struct usb_function *f, 3802 const struct usb_ctrlrequest *creq) 3803 { 3804 struct ffs_function *func = ffs_func_from_usb(f); 3805 struct ffs_data *ffs = func->ffs; 3806 unsigned long flags; 3807 int ret; 3808 3809 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType); 3810 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest); 3811 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue)); 3812 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex)); 3813 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength)); 3814 3815 /* 3816 * Most requests directed to interface go through here 3817 * (notable exceptions are set/get interface) so we need to 3818 * handle them. All other either handled by composite or 3819 * passed to usb_configuration->setup() (if one is set). No 3820 * matter, we will handle requests directed to endpoint here 3821 * as well (as it's straightforward). Other request recipient 3822 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP 3823 * is being used. 3824 */ 3825 if (ffs->state != FFS_ACTIVE) 3826 return -ENODEV; 3827 3828 switch (creq->bRequestType & USB_RECIP_MASK) { 3829 case USB_RECIP_INTERFACE: 3830 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex)); 3831 if (ret < 0) 3832 return ret; 3833 break; 3834 3835 case USB_RECIP_ENDPOINT: 3836 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex)); 3837 if (ret < 0) 3838 return ret; 3839 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 3840 ret = func->ffs->eps_addrmap[ret]; 3841 break; 3842 3843 default: 3844 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP) 3845 ret = le16_to_cpu(creq->wIndex); 3846 else 3847 return -EOPNOTSUPP; 3848 } 3849 3850 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 3851 ffs->ev.setup = *creq; 3852 ffs->ev.setup.wIndex = cpu_to_le16(ret); 3853 __ffs_event_add(ffs, FUNCTIONFS_SETUP); 3854 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 3855 3856 return ffs->ev.setup.wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0; 3857 } 3858 3859 static bool ffs_func_req_match(struct usb_function *f, 3860 const struct usb_ctrlrequest *creq, 3861 bool config0) 3862 { 3863 struct ffs_function *func = ffs_func_from_usb(f); 3864 3865 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP)) 3866 return false; 3867 3868 switch (creq->bRequestType & USB_RECIP_MASK) { 3869 case USB_RECIP_INTERFACE: 3870 return (ffs_func_revmap_intf(func, 3871 le16_to_cpu(creq->wIndex)) >= 0); 3872 case USB_RECIP_ENDPOINT: 3873 return (ffs_func_revmap_ep(func, 3874 le16_to_cpu(creq->wIndex)) >= 0); 3875 default: 3876 return (bool) (func->ffs->user_flags & 3877 FUNCTIONFS_ALL_CTRL_RECIP); 3878 } 3879 } 3880 3881 static void ffs_func_suspend(struct usb_function *f) 3882 { 3883 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND); 3884 } 3885 3886 static void ffs_func_resume(struct usb_function *f) 3887 { 3888 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME); 3889 } 3890 3891 3892 /* Endpoint and interface numbers reverse mapping ***************************/ 3893 3894 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) 3895 { 3896 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK]; 3897 return num ? num : -EDOM; 3898 } 3899 3900 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) 3901 { 3902 short *nums = func->interfaces_nums; 3903 unsigned count = func->ffs->interfaces_count; 3904 3905 for (; count; --count, ++nums) { 3906 if (*nums >= 0 && *nums == intf) 3907 return nums - func->interfaces_nums; 3908 } 3909 3910 return -EDOM; 3911 } 3912 3913 3914 /* Devices management *******************************************************/ 3915 3916 static LIST_HEAD(ffs_devices); 3917 3918 static struct ffs_dev *_ffs_do_find_dev(const char *name) 3919 { 3920 struct ffs_dev *dev; 3921 3922 if (!name) 3923 return NULL; 3924 3925 list_for_each_entry(dev, &ffs_devices, entry) { 3926 if (strcmp(dev->name, name) == 0) 3927 return dev; 3928 } 3929 3930 return NULL; 3931 } 3932 3933 /* 3934 * ffs_lock must be taken by the caller of this function 3935 */ 3936 static struct ffs_dev *_ffs_get_single_dev(void) 3937 { 3938 struct ffs_dev *dev; 3939 3940 if (list_is_singular(&ffs_devices)) { 3941 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry); 3942 if (dev->single) 3943 return dev; 3944 } 3945 3946 return NULL; 3947 } 3948 3949 /* 3950 * ffs_lock must be taken by the caller of this function 3951 */ 3952 static struct ffs_dev *_ffs_find_dev(const char *name) 3953 { 3954 struct ffs_dev *dev; 3955 3956 dev = _ffs_get_single_dev(); 3957 if (dev) 3958 return dev; 3959 3960 return _ffs_do_find_dev(name); 3961 } 3962 3963 /* Configfs support *********************************************************/ 3964 3965 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item) 3966 { 3967 return container_of(to_config_group(item), struct f_fs_opts, 3968 func_inst.group); 3969 } 3970 3971 static ssize_t f_fs_opts_ready_show(struct config_item *item, char *page) 3972 { 3973 struct f_fs_opts *opts = to_ffs_opts(item); 3974 int ready; 3975 3976 ffs_dev_lock(); 3977 ready = opts->dev->desc_ready; 3978 ffs_dev_unlock(); 3979 3980 return sprintf(page, "%d\n", ready); 3981 } 3982 3983 CONFIGFS_ATTR_RO(f_fs_opts_, ready); 3984 3985 static struct configfs_attribute *ffs_attrs[] = { 3986 &f_fs_opts_attr_ready, 3987 NULL, 3988 }; 3989 3990 static void ffs_attr_release(struct config_item *item) 3991 { 3992 struct f_fs_opts *opts = to_ffs_opts(item); 3993 3994 usb_put_function_instance(&opts->func_inst); 3995 } 3996 3997 static const struct configfs_item_operations ffs_item_ops = { 3998 .release = ffs_attr_release, 3999 }; 4000 4001 static const struct config_item_type ffs_func_type = { 4002 .ct_item_ops = &ffs_item_ops, 4003 .ct_attrs = ffs_attrs, 4004 .ct_owner = THIS_MODULE, 4005 }; 4006 4007 4008 /* Function registration interface ******************************************/ 4009 4010 static void ffs_free_inst(struct usb_function_instance *f) 4011 { 4012 struct f_fs_opts *opts; 4013 4014 opts = to_f_fs_opts(f); 4015 ffs_release_dev(opts->dev); 4016 ffs_dev_lock(); 4017 _ffs_free_dev(opts->dev); 4018 ffs_dev_unlock(); 4019 kfree(opts); 4020 } 4021 4022 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name) 4023 { 4024 if (strlen(name) >= sizeof_field(struct ffs_dev, name)) 4025 return -ENAMETOOLONG; 4026 return ffs_name_dev(to_f_fs_opts(fi)->dev, name); 4027 } 4028 4029 static struct usb_function_instance *ffs_alloc_inst(void) 4030 { 4031 struct f_fs_opts *opts; 4032 struct ffs_dev *dev; 4033 4034 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 4035 if (!opts) 4036 return ERR_PTR(-ENOMEM); 4037 4038 opts->func_inst.set_inst_name = ffs_set_inst_name; 4039 opts->func_inst.free_func_inst = ffs_free_inst; 4040 ffs_dev_lock(); 4041 dev = _ffs_alloc_dev(); 4042 ffs_dev_unlock(); 4043 if (IS_ERR(dev)) { 4044 kfree(opts); 4045 return ERR_CAST(dev); 4046 } 4047 opts->dev = dev; 4048 dev->opts = opts; 4049 4050 config_group_init_type_name(&opts->func_inst.group, "", 4051 &ffs_func_type); 4052 return &opts->func_inst; 4053 } 4054 4055 static void ffs_free(struct usb_function *f) 4056 { 4057 kfree(ffs_func_from_usb(f)); 4058 } 4059 4060 static void ffs_func_unbind(struct usb_configuration *c, 4061 struct usb_function *f) 4062 { 4063 struct ffs_function *func = ffs_func_from_usb(f); 4064 struct ffs_data *ffs = func->ffs; 4065 struct f_fs_opts *opts = 4066 container_of(f->fi, struct f_fs_opts, func_inst); 4067 struct ffs_ep *ep = func->eps; 4068 unsigned count = ffs->eps_count; 4069 unsigned long flags; 4070 4071 if (ffs->func == func) { 4072 ffs_func_eps_disable(func); 4073 ffs->func = NULL; 4074 } 4075 4076 /* Drain any pending AIO completions */ 4077 drain_workqueue(ffs->io_completion_wq); 4078 4079 ffs_event_add(ffs, FUNCTIONFS_UNBIND); 4080 if (!--opts->refcnt) 4081 functionfs_unbind(ffs); 4082 4083 /* cleanup after autoconfig */ 4084 spin_lock_irqsave(&func->ffs->eps_lock, flags); 4085 while (count--) { 4086 if (ep->ep && ep->req) 4087 usb_ep_free_request(ep->ep, ep->req); 4088 ep->req = NULL; 4089 ++ep; 4090 } 4091 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 4092 kfree(func->eps); 4093 func->eps = NULL; 4094 /* 4095 * eps, descriptors and interfaces_nums are allocated in the 4096 * same chunk so only one free is required. 4097 */ 4098 func->function.fs_descriptors = NULL; 4099 func->function.hs_descriptors = NULL; 4100 func->function.ss_descriptors = NULL; 4101 func->function.ssp_descriptors = NULL; 4102 func->interfaces_nums = NULL; 4103 4104 } 4105 4106 static struct usb_function *ffs_alloc(struct usb_function_instance *fi) 4107 { 4108 struct ffs_function *func; 4109 4110 func = kzalloc(sizeof(*func), GFP_KERNEL); 4111 if (!func) 4112 return ERR_PTR(-ENOMEM); 4113 4114 func->function.name = "Function FS Gadget"; 4115 4116 func->function.bind = ffs_func_bind; 4117 func->function.unbind = ffs_func_unbind; 4118 func->function.set_alt = ffs_func_set_alt; 4119 func->function.get_alt = ffs_func_get_alt; 4120 func->function.disable = ffs_func_disable; 4121 func->function.setup = ffs_func_setup; 4122 func->function.req_match = ffs_func_req_match; 4123 func->function.suspend = ffs_func_suspend; 4124 func->function.resume = ffs_func_resume; 4125 func->function.free_func = ffs_free; 4126 4127 return &func->function; 4128 } 4129 4130 /* 4131 * ffs_lock must be taken by the caller of this function 4132 */ 4133 static struct ffs_dev *_ffs_alloc_dev(void) 4134 { 4135 struct ffs_dev *dev; 4136 int ret; 4137 4138 if (_ffs_get_single_dev()) 4139 return ERR_PTR(-EBUSY); 4140 4141 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 4142 if (!dev) 4143 return ERR_PTR(-ENOMEM); 4144 4145 if (list_empty(&ffs_devices)) { 4146 ret = functionfs_init(); 4147 if (ret) { 4148 kfree(dev); 4149 return ERR_PTR(ret); 4150 } 4151 } 4152 4153 list_add(&dev->entry, &ffs_devices); 4154 4155 return dev; 4156 } 4157 4158 int ffs_name_dev(struct ffs_dev *dev, const char *name) 4159 { 4160 struct ffs_dev *existing; 4161 int ret = 0; 4162 4163 ffs_dev_lock(); 4164 4165 existing = _ffs_do_find_dev(name); 4166 if (!existing) 4167 strscpy(dev->name, name, ARRAY_SIZE(dev->name)); 4168 else if (existing != dev) 4169 ret = -EBUSY; 4170 4171 ffs_dev_unlock(); 4172 4173 return ret; 4174 } 4175 EXPORT_SYMBOL_GPL(ffs_name_dev); 4176 4177 int ffs_single_dev(struct ffs_dev *dev) 4178 { 4179 int ret; 4180 4181 ret = 0; 4182 ffs_dev_lock(); 4183 4184 if (!list_is_singular(&ffs_devices)) 4185 ret = -EBUSY; 4186 else 4187 dev->single = true; 4188 4189 ffs_dev_unlock(); 4190 return ret; 4191 } 4192 EXPORT_SYMBOL_GPL(ffs_single_dev); 4193 4194 /* 4195 * ffs_lock must be taken by the caller of this function 4196 */ 4197 static void _ffs_free_dev(struct ffs_dev *dev) 4198 { 4199 list_del(&dev->entry); 4200 4201 kfree(dev); 4202 if (list_empty(&ffs_devices)) 4203 functionfs_cleanup(); 4204 } 4205 4206 static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data) 4207 { 4208 int ret = 0; 4209 struct ffs_dev *ffs_dev; 4210 4211 ffs_dev_lock(); 4212 4213 ffs_dev = _ffs_find_dev(dev_name); 4214 if (!ffs_dev) { 4215 ret = -ENOENT; 4216 } else if (ffs_dev->mounted) { 4217 ret = -EBUSY; 4218 } else if (ffs_dev->ffs_acquire_dev_callback && 4219 ffs_dev->ffs_acquire_dev_callback(ffs_dev)) { 4220 ret = -ENOENT; 4221 } else { 4222 ffs_dev->mounted = true; 4223 ffs_dev->ffs_data = ffs_data; 4224 ffs_data->private_data = ffs_dev; 4225 } 4226 4227 ffs_dev_unlock(); 4228 return ret; 4229 } 4230 4231 static void ffs_release_dev(struct ffs_dev *ffs_dev) 4232 { 4233 ffs_dev_lock(); 4234 4235 if (ffs_dev && ffs_dev->mounted) { 4236 ffs_dev->mounted = false; 4237 if (ffs_dev->ffs_data) { 4238 ffs_dev->ffs_data->private_data = NULL; 4239 ffs_dev->ffs_data = NULL; 4240 } 4241 4242 if (ffs_dev->ffs_release_dev_callback) 4243 ffs_dev->ffs_release_dev_callback(ffs_dev); 4244 } 4245 4246 ffs_dev_unlock(); 4247 } 4248 4249 static int ffs_ready(struct ffs_data *ffs) 4250 { 4251 struct ffs_dev *ffs_obj; 4252 int ret = 0; 4253 4254 ffs_dev_lock(); 4255 4256 ffs_obj = ffs->private_data; 4257 if (!ffs_obj) { 4258 ret = -EINVAL; 4259 goto done; 4260 } 4261 if (WARN_ON(ffs_obj->desc_ready)) { 4262 ret = -EBUSY; 4263 goto done; 4264 } 4265 4266 ffs_obj->desc_ready = true; 4267 4268 if (ffs_obj->ffs_ready_callback) { 4269 ret = ffs_obj->ffs_ready_callback(ffs); 4270 if (ret) 4271 goto done; 4272 } 4273 4274 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags); 4275 done: 4276 ffs_dev_unlock(); 4277 return ret; 4278 } 4279 4280 static void ffs_closed(struct ffs_data *ffs) 4281 { 4282 struct ffs_dev *ffs_obj; 4283 struct f_fs_opts *opts; 4284 struct config_item *ci; 4285 4286 ffs_dev_lock(); 4287 4288 ffs_obj = ffs->private_data; 4289 if (!ffs_obj) 4290 goto done; 4291 4292 ffs_obj->desc_ready = false; 4293 4294 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && 4295 ffs_obj->ffs_closed_callback) 4296 ffs_obj->ffs_closed_callback(ffs); 4297 4298 if (ffs_obj->opts) 4299 opts = ffs_obj->opts; 4300 else 4301 goto done; 4302 4303 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent 4304 || !kref_read(&opts->func_inst.group.cg_item.ci_kref)) 4305 goto done; 4306 4307 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent; 4308 ffs_dev_unlock(); 4309 4310 if (test_bit(FFS_FL_BOUND, &ffs->flags)) 4311 unregister_gadget_item(ci); 4312 return; 4313 done: 4314 ffs_dev_unlock(); 4315 } 4316 4317 /* Misc helper functions ****************************************************/ 4318 4319 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 4320 { 4321 return nonblock 4322 ? mutex_trylock(mutex) ? 0 : -EAGAIN 4323 : mutex_lock_interruptible(mutex); 4324 } 4325 4326 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 4327 { 4328 char *data; 4329 4330 if (!len) 4331 return NULL; 4332 4333 data = memdup_user(buf, len); 4334 if (IS_ERR(data)) 4335 return data; 4336 4337 pr_vdebug("Buffer from user space:\n"); 4338 ffs_dump_mem("", data, len); 4339 4340 return data; 4341 } 4342 4343 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc); 4344 MODULE_DESCRIPTION("user mode file system API for USB composite function controllers"); 4345 MODULE_LICENSE("GPL"); 4346 MODULE_AUTHOR("Michal Nazarewicz"); 4347