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 struct usb_ep *ep; 154 struct usb_request *req; 155 }; 156 157 struct ffs_epfile { 158 /* Protects ep->ep and ep->req. */ 159 struct mutex mutex; 160 161 struct ffs_data *ffs; 162 struct ffs_ep *ep; /* P: ffs->eps_lock */ 163 struct ffs_epfile *epfile_in; /* P: ffs->eps_lock */ 164 struct ffs_epfile *epfile_out; /* P: ffs->eps_lock */ 165 166 /* 167 * Buffer for holding data from partial reads which may happen since 168 * we’re rounding user read requests to a multiple of a max packet size. 169 * 170 * The pointer is initialised with NULL value and may be set by 171 * __ffs_epfile_read_data function to point to a temporary buffer. 172 * 173 * In normal operation, calls to __ffs_epfile_read_buffered will consume 174 * data from said buffer and eventually free it. Importantly, while the 175 * function is using the buffer, it sets the pointer to NULL. This is 176 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered 177 * can never run concurrently (they are synchronised by epfile->mutex) 178 * so the latter will not assign a new value to the pointer. 179 * 180 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is 181 * valid) and sets the pointer to READ_BUFFER_DROP value. This special 182 * value is crux of the synchronisation between ffs_func_eps_disable and 183 * __ffs_epfile_read_data. 184 * 185 * Once __ffs_epfile_read_data is about to finish it will try to set the 186 * pointer back to its old value (as described above), but seeing as the 187 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free 188 * the buffer. 189 * 190 * == State transitions == 191 * 192 * • ptr == NULL: (initial state) 193 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP 194 * ◦ __ffs_epfile_read_buffered: nop 195 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf 196 * ◦ reading finishes: n/a, not in ‘and reading’ state 197 * • ptr == DROP: 198 * ◦ __ffs_epfile_read_buffer_free: nop 199 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL 200 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop 201 * ◦ reading finishes: n/a, not in ‘and reading’ state 202 * • ptr == buf: 203 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP 204 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading 205 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered 206 * is always called first 207 * ◦ reading finishes: n/a, not in ‘and reading’ state 208 * • ptr == NULL and reading: 209 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading 210 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held 211 * ◦ __ffs_epfile_read_data: n/a, mutex is held 212 * ◦ reading finishes and … 213 * … all data read: free buf, go to ptr == NULL 214 * … otherwise: go to ptr == buf and reading 215 * • ptr == DROP and reading: 216 * ◦ __ffs_epfile_read_buffer_free: nop 217 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held 218 * ◦ __ffs_epfile_read_data: n/a, mutex is held 219 * ◦ reading finishes: free buf, go to ptr == DROP 220 */ 221 struct ffs_buffer *read_buffer; 222 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN)) 223 224 char name[8]; 225 226 unsigned char in; /* P: ffs->eps_lock */ 227 unsigned char isoc; /* P: ffs->eps_lock */ 228 229 u8 zlp_enabled; /* P: ffs->eps_lock */ 230 bool is_rw_proxy; 231 232 /* Protects dmabufs */ 233 struct mutex dmabufs_mutex; 234 struct list_head dmabufs; /* P: dmabufs_mutex */ 235 atomic_t seqno; 236 }; 237 238 struct ffs_buffer { 239 size_t length; 240 char *data; 241 char storage[] __counted_by(length); 242 }; 243 244 /* ffs_io_data structure ***************************************************/ 245 246 struct ffs_io_data { 247 bool aio; 248 bool read; 249 250 struct kiocb *kiocb; 251 struct iov_iter data; 252 const void *to_free; 253 char *buf; 254 255 struct mm_struct *mm; 256 struct work_struct work; 257 258 struct usb_ep *ep; 259 struct usb_request *req; 260 struct sg_table sgt; 261 bool use_sg; 262 263 struct ffs_data *ffs; 264 265 int status; 266 struct completion done; 267 }; 268 269 struct ffs_desc_helper { 270 struct ffs_data *ffs; 271 unsigned interfaces_count; 272 unsigned eps_count; 273 }; 274 275 static int __must_check ffs_epfiles_create(struct ffs_data *ffs); 276 static void ffs_epfiles_destroy(struct super_block *sb, 277 struct ffs_epfile *epfiles, unsigned count); 278 279 static int ffs_sb_create_file(struct super_block *sb, const char *name, 280 void *data, const struct file_operations *fops); 281 282 /* Devices management *******************************************************/ 283 284 DEFINE_MUTEX(ffs_lock); 285 EXPORT_SYMBOL_GPL(ffs_lock); 286 287 static struct ffs_dev *_ffs_find_dev(const char *name); 288 static struct ffs_dev *_ffs_alloc_dev(void); 289 static void _ffs_free_dev(struct ffs_dev *dev); 290 static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data); 291 static void ffs_release_dev(struct ffs_dev *ffs_dev); 292 static int ffs_ready(struct ffs_data *ffs); 293 static void ffs_closed(struct ffs_data *ffs); 294 static void ffs_reset_work(struct work_struct *work); 295 296 /* Misc helper functions ****************************************************/ 297 298 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 299 __attribute__((warn_unused_result, nonnull)); 300 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 301 __attribute__((warn_unused_result, nonnull)); 302 303 304 /* Control file aka ep0 *****************************************************/ 305 306 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req) 307 { 308 struct ffs_data *ffs = req->context; 309 310 complete(&ffs->ep0req_completion); 311 } 312 313 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len) 314 __releases(&ffs->ev.waitq.lock) 315 { 316 struct usb_request *req = ffs->ep0req; 317 int ret; 318 319 if (!req) { 320 spin_unlock_irq(&ffs->ev.waitq.lock); 321 return -EINVAL; 322 } 323 324 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength); 325 326 spin_unlock_irq(&ffs->ev.waitq.lock); 327 328 req->buf = data; 329 req->length = len; 330 331 /* 332 * UDC layer requires to provide a buffer even for ZLP, but should 333 * not use it at all. Let's provide some poisoned pointer to catch 334 * possible bug in the driver. 335 */ 336 if (req->buf == NULL) 337 req->buf = (void *)0xDEADBABE; 338 339 reinit_completion(&ffs->ep0req_completion); 340 341 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC); 342 if (ret < 0) 343 return ret; 344 345 ret = wait_for_completion_interruptible(&ffs->ep0req_completion); 346 if (ret) { 347 usb_ep_dequeue(ffs->gadget->ep0, req); 348 return -EINTR; 349 } 350 351 ffs->setup_state = FFS_NO_SETUP; 352 return req->status ? req->status : req->actual; 353 } 354 355 static int __ffs_ep0_stall(struct ffs_data *ffs) 356 { 357 if (ffs->ev.can_stall) { 358 pr_vdebug("ep0 stall\n"); 359 usb_ep_set_halt(ffs->gadget->ep0); 360 ffs->setup_state = FFS_NO_SETUP; 361 return -EL2HLT; 362 } else { 363 pr_debug("bogus ep0 stall!\n"); 364 return -ESRCH; 365 } 366 } 367 368 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, 369 size_t len, loff_t *ptr) 370 { 371 struct ffs_data *ffs = file->private_data; 372 ssize_t ret; 373 char *data; 374 375 /* Fast check if setup was canceled */ 376 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 377 return -EIDRM; 378 379 /* Acquire mutex */ 380 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 381 if (ret < 0) 382 return ret; 383 384 /* Check state */ 385 switch (ffs->state) { 386 case FFS_READ_DESCRIPTORS: 387 case FFS_READ_STRINGS: 388 /* Copy data */ 389 if (len < 16) { 390 ret = -EINVAL; 391 break; 392 } 393 394 data = ffs_prepare_buffer(buf, len); 395 if (IS_ERR(data)) { 396 ret = PTR_ERR(data); 397 break; 398 } 399 400 /* Handle data */ 401 if (ffs->state == FFS_READ_DESCRIPTORS) { 402 pr_info("read descriptors\n"); 403 ret = __ffs_data_got_descs(ffs, data, len); 404 if (ret < 0) 405 break; 406 407 ffs->state = FFS_READ_STRINGS; 408 ret = len; 409 } else { 410 pr_info("read strings\n"); 411 ret = __ffs_data_got_strings(ffs, data, len); 412 if (ret < 0) 413 break; 414 415 ret = ffs_epfiles_create(ffs); 416 if (ret) { 417 ffs->state = FFS_CLOSING; 418 break; 419 } 420 421 ffs->state = FFS_ACTIVE; 422 mutex_unlock(&ffs->mutex); 423 424 ret = ffs_ready(ffs); 425 if (ret < 0) { 426 ffs->state = FFS_CLOSING; 427 return ret; 428 } 429 430 return len; 431 } 432 break; 433 434 case FFS_ACTIVE: 435 data = NULL; 436 /* 437 * We're called from user space, we can use _irq 438 * rather then _irqsave 439 */ 440 spin_lock_irq(&ffs->ev.waitq.lock); 441 switch (ffs_setup_state_clear_cancelled(ffs)) { 442 case FFS_SETUP_CANCELLED: 443 ret = -EIDRM; 444 goto done_spin; 445 446 case FFS_NO_SETUP: 447 ret = -ESRCH; 448 goto done_spin; 449 450 case FFS_SETUP_PENDING: 451 break; 452 } 453 454 /* FFS_SETUP_PENDING */ 455 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) { 456 spin_unlock_irq(&ffs->ev.waitq.lock); 457 ret = __ffs_ep0_stall(ffs); 458 break; 459 } 460 461 /* FFS_SETUP_PENDING and not stall */ 462 len = min_t(size_t, len, le16_to_cpu(ffs->ev.setup.wLength)); 463 464 spin_unlock_irq(&ffs->ev.waitq.lock); 465 466 data = ffs_prepare_buffer(buf, len); 467 if (IS_ERR(data)) { 468 ret = PTR_ERR(data); 469 break; 470 } 471 472 spin_lock_irq(&ffs->ev.waitq.lock); 473 474 /* 475 * We are guaranteed to be still in FFS_ACTIVE state 476 * but the state of setup could have changed from 477 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need 478 * to check for that. If that happened we copied data 479 * from user space in vain but it's unlikely. 480 * 481 * For sure we are not in FFS_NO_SETUP since this is 482 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP 483 * transition can be performed and it's protected by 484 * mutex. 485 */ 486 if (ffs_setup_state_clear_cancelled(ffs) == 487 FFS_SETUP_CANCELLED) { 488 ret = -EIDRM; 489 done_spin: 490 spin_unlock_irq(&ffs->ev.waitq.lock); 491 } else { 492 /* unlocks spinlock */ 493 ret = __ffs_ep0_queue_wait(ffs, data, len); 494 } 495 kfree(data); 496 break; 497 498 default: 499 ret = -EBADFD; 500 break; 501 } 502 503 mutex_unlock(&ffs->mutex); 504 return ret; 505 } 506 507 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */ 508 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf, 509 size_t n) 510 __releases(&ffs->ev.waitq.lock) 511 { 512 /* 513 * n cannot be bigger than ffs->ev.count, which cannot be bigger than 514 * size of ffs->ev.types array (which is four) so that's how much space 515 * we reserve. 516 */ 517 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)]; 518 const size_t size = n * sizeof *events; 519 unsigned i = 0; 520 521 memset(events, 0, size); 522 523 do { 524 events[i].type = ffs->ev.types[i]; 525 if (events[i].type == FUNCTIONFS_SETUP) { 526 events[i].u.setup = ffs->ev.setup; 527 ffs->setup_state = FFS_SETUP_PENDING; 528 } 529 } while (++i < n); 530 531 ffs->ev.count -= n; 532 if (ffs->ev.count) 533 memmove(ffs->ev.types, ffs->ev.types + n, 534 ffs->ev.count * sizeof *ffs->ev.types); 535 536 spin_unlock_irq(&ffs->ev.waitq.lock); 537 mutex_unlock(&ffs->mutex); 538 539 return copy_to_user(buf, events, size) ? -EFAULT : size; 540 } 541 542 static ssize_t ffs_ep0_read(struct file *file, char __user *buf, 543 size_t len, loff_t *ptr) 544 { 545 struct ffs_data *ffs = file->private_data; 546 char *data = NULL; 547 size_t n; 548 int ret; 549 550 /* Fast check if setup was canceled */ 551 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 552 return -EIDRM; 553 554 retry: 555 /* Acquire mutex */ 556 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 557 if (ret < 0) 558 return ret; 559 560 /* Check state */ 561 if (ffs->state != FFS_ACTIVE) { 562 ret = -EBADFD; 563 goto done_mutex; 564 } 565 566 /* 567 * We're called from user space, we can use _irq rather then 568 * _irqsave 569 */ 570 spin_lock_irq(&ffs->ev.waitq.lock); 571 572 switch (ffs_setup_state_clear_cancelled(ffs)) { 573 case FFS_SETUP_CANCELLED: 574 ret = -EIDRM; 575 break; 576 577 case FFS_NO_SETUP: 578 n = len / sizeof(struct usb_functionfs_event); 579 if (!n) { 580 ret = -EINVAL; 581 break; 582 } 583 584 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) { 585 ret = -EAGAIN; 586 break; 587 } 588 589 if (!ffs->ev.count) { 590 spin_unlock_irq(&ffs->ev.waitq.lock); 591 mutex_unlock(&ffs->mutex); 592 593 if (wait_event_interruptible_exclusive(ffs->ev.waitq, 594 ffs->ev.count)) 595 return -EINTR; 596 597 goto retry; 598 } 599 600 /* unlocks spinlock */ 601 return __ffs_ep0_read_events(ffs, buf, 602 min_t(size_t, n, ffs->ev.count)); 603 604 case FFS_SETUP_PENDING: 605 if (ffs->ev.setup.bRequestType & USB_DIR_IN) { 606 spin_unlock_irq(&ffs->ev.waitq.lock); 607 ret = __ffs_ep0_stall(ffs); 608 goto done_mutex; 609 } 610 611 len = min_t(size_t, len, le16_to_cpu(ffs->ev.setup.wLength)); 612 613 spin_unlock_irq(&ffs->ev.waitq.lock); 614 615 if (len) { 616 data = kmalloc(len, GFP_KERNEL); 617 if (!data) { 618 ret = -ENOMEM; 619 goto done_mutex; 620 } 621 } 622 623 spin_lock_irq(&ffs->ev.waitq.lock); 624 625 /* See ffs_ep0_write() */ 626 if (ffs_setup_state_clear_cancelled(ffs) == 627 FFS_SETUP_CANCELLED) { 628 ret = -EIDRM; 629 break; 630 } 631 632 /* unlocks spinlock */ 633 ret = __ffs_ep0_queue_wait(ffs, data, len); 634 if ((ret > 0) && (copy_to_user(buf, data, ret))) 635 ret = -EFAULT; 636 goto done_mutex; 637 638 default: 639 ret = -EBADFD; 640 break; 641 } 642 643 spin_unlock_irq(&ffs->ev.waitq.lock); 644 done_mutex: 645 mutex_unlock(&ffs->mutex); 646 kfree(data); 647 return ret; 648 } 649 650 651 static void ffs_data_reset(struct ffs_data *ffs); 652 653 static int ffs_ep0_open(struct inode *inode, struct file *file) 654 { 655 struct ffs_data *ffs = inode->i_sb->s_fs_info; 656 657 spin_lock_irq(&ffs->eps_lock); 658 if (ffs->state == FFS_CLOSING) { 659 spin_unlock_irq(&ffs->eps_lock); 660 return -EBUSY; 661 } 662 if (!ffs->opened++ && ffs->state == FFS_DEACTIVATED) { 663 ffs->state = FFS_CLOSING; 664 spin_unlock_irq(&ffs->eps_lock); 665 ffs_data_reset(ffs); 666 } else { 667 spin_unlock_irq(&ffs->eps_lock); 668 } 669 file->private_data = ffs; 670 671 return stream_open(inode, file); 672 } 673 674 static int ffs_ep0_release(struct inode *inode, struct file *file) 675 { 676 struct ffs_data *ffs = file->private_data; 677 678 ffs_data_closed(ffs); 679 680 return 0; 681 } 682 683 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) 684 { 685 struct ffs_data *ffs = file->private_data; 686 struct usb_gadget *gadget = ffs->gadget; 687 long ret; 688 689 if (code == FUNCTIONFS_INTERFACE_REVMAP) { 690 struct ffs_function *func = ffs->func; 691 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV; 692 } else if (gadget && gadget->ops->ioctl) { 693 ret = gadget->ops->ioctl(gadget, code, value); 694 } else { 695 ret = -ENOTTY; 696 } 697 698 return ret; 699 } 700 701 static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait) 702 { 703 struct ffs_data *ffs = file->private_data; 704 __poll_t mask = EPOLLWRNORM; 705 int ret; 706 707 poll_wait(file, &ffs->ev.waitq, wait); 708 709 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 710 if (ret < 0) 711 return mask; 712 713 switch (ffs->state) { 714 case FFS_READ_DESCRIPTORS: 715 case FFS_READ_STRINGS: 716 mask |= EPOLLOUT; 717 break; 718 719 case FFS_ACTIVE: 720 switch (ffs->setup_state) { 721 case FFS_NO_SETUP: 722 if (ffs->ev.count) 723 mask |= EPOLLIN; 724 break; 725 726 case FFS_SETUP_PENDING: 727 case FFS_SETUP_CANCELLED: 728 mask |= (EPOLLIN | EPOLLOUT); 729 break; 730 } 731 break; 732 733 case FFS_CLOSING: 734 break; 735 case FFS_DEACTIVATED: 736 break; 737 } 738 739 mutex_unlock(&ffs->mutex); 740 741 return mask; 742 } 743 744 static const struct file_operations ffs_ep0_operations = { 745 746 .open = ffs_ep0_open, 747 .write = ffs_ep0_write, 748 .read = ffs_ep0_read, 749 .release = ffs_ep0_release, 750 .unlocked_ioctl = ffs_ep0_ioctl, 751 .poll = ffs_ep0_poll, 752 }; 753 754 755 /* "Normal" endpoints operations ********************************************/ 756 757 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) 758 { 759 struct ffs_io_data *io_data = req->context; 760 761 if (req->status) 762 io_data->status = req->status; 763 else 764 io_data->status = req->actual; 765 766 complete(&io_data->done); 767 } 768 769 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter) 770 { 771 ssize_t ret = copy_to_iter(data, data_len, iter); 772 if (ret == data_len) 773 return ret; 774 775 if (iov_iter_count(iter)) 776 return -EFAULT; 777 778 /* 779 * Dear user space developer! 780 * 781 * TL;DR: To stop getting below error message in your kernel log, change 782 * user space code using functionfs to align read buffers to a max 783 * packet size. 784 * 785 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max 786 * packet size. When unaligned buffer is passed to functionfs, it 787 * internally uses a larger, aligned buffer so that such UDCs are happy. 788 * 789 * Unfortunately, this means that host may send more data than was 790 * requested in read(2) system call. f_fs doesn’t know what to do with 791 * that excess data so it simply drops it. 792 * 793 * Was the buffer aligned in the first place, no such problem would 794 * happen. 795 * 796 * Data may be dropped only in AIO reads. Synchronous reads are handled 797 * by splitting a request into multiple parts. This splitting may still 798 * be a problem though so it’s likely best to align the buffer 799 * regardless of it being AIO or not.. 800 * 801 * This only affects OUT endpoints, i.e. reading data with a read(2), 802 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not 803 * affected. 804 */ 805 pr_err("functionfs read size %d > requested size %zd, dropping excess data. " 806 "Align read buffer size to max packet size to avoid the problem.\n", 807 data_len, ret); 808 809 return ret; 810 } 811 812 /* 813 * allocate a virtually contiguous buffer and create a scatterlist describing it 814 * @sg_table - pointer to a place to be filled with sg_table contents 815 * @size - required buffer size 816 */ 817 static void *ffs_build_sg_list(struct sg_table *sgt, size_t sz) 818 { 819 struct page **pages; 820 void *vaddr, *ptr; 821 unsigned int n_pages; 822 int i; 823 824 vaddr = vmalloc(sz); 825 if (!vaddr) 826 return NULL; 827 828 n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT; 829 pages = kvmalloc_objs(struct page *, n_pages); 830 if (!pages) { 831 vfree(vaddr); 832 833 return NULL; 834 } 835 for (i = 0, ptr = vaddr; i < n_pages; ++i, ptr += PAGE_SIZE) 836 pages[i] = vmalloc_to_page(ptr); 837 838 if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) { 839 kvfree(pages); 840 vfree(vaddr); 841 842 return NULL; 843 } 844 kvfree(pages); 845 846 return vaddr; 847 } 848 849 static inline void *ffs_alloc_buffer(struct ffs_io_data *io_data, 850 size_t data_len) 851 { 852 if (io_data->use_sg) 853 return ffs_build_sg_list(&io_data->sgt, data_len); 854 855 return kmalloc(data_len, GFP_KERNEL); 856 } 857 858 static inline void ffs_free_buffer(struct ffs_io_data *io_data) 859 { 860 if (!io_data->buf) 861 return; 862 863 if (io_data->use_sg) { 864 sg_free_table(&io_data->sgt); 865 vfree(io_data->buf); 866 } else { 867 kfree(io_data->buf); 868 } 869 } 870 871 static void ffs_user_copy_worker(struct work_struct *work) 872 { 873 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data, 874 work); 875 int ret = io_data->status; 876 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD; 877 878 if (io_data->read && ret > 0) { 879 if (mmget_not_zero(io_data->mm)) { 880 kthread_use_mm(io_data->mm); 881 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); 882 kthread_unuse_mm(io_data->mm); 883 mmput(io_data->mm); 884 } else { 885 ret = -EFAULT; 886 } 887 mmdrop(io_data->mm); 888 } 889 890 io_data->kiocb->ki_complete(io_data->kiocb, ret); 891 892 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd) 893 eventfd_signal(io_data->ffs->ffs_eventfd); 894 895 usb_ep_free_request(io_data->ep, io_data->req); 896 897 if (io_data->read) 898 kfree(io_data->to_free); 899 ffs_free_buffer(io_data); 900 kfree(io_data); 901 } 902 903 static void ffs_epfile_async_io_complete(struct usb_ep *_ep, 904 struct usb_request *req) 905 { 906 struct ffs_io_data *io_data = req->context; 907 struct ffs_data *ffs = io_data->ffs; 908 909 io_data->status = req->status ? req->status : req->actual; 910 911 INIT_WORK(&io_data->work, ffs_user_copy_worker); 912 queue_work(ffs->io_completion_wq, &io_data->work); 913 } 914 915 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile) 916 { 917 /* 918 * See comment in struct ffs_epfile for full read_buffer pointer 919 * synchronisation story. 920 */ 921 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP); 922 if (buf && buf != READ_BUFFER_DROP) 923 kfree(buf); 924 } 925 926 /* Assumes epfile->mutex is held. */ 927 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile, 928 struct iov_iter *iter) 929 { 930 /* 931 * Null out epfile->read_buffer so ffs_func_eps_disable does not free 932 * the buffer while we are using it. See comment in struct ffs_epfile 933 * for full read_buffer pointer synchronisation story. 934 */ 935 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL); 936 ssize_t ret; 937 if (!buf || buf == READ_BUFFER_DROP) 938 return 0; 939 940 ret = copy_to_iter(buf->data, buf->length, iter); 941 if (buf->length == ret) { 942 kfree(buf); 943 return ret; 944 } 945 946 if (iov_iter_count(iter)) { 947 ret = -EFAULT; 948 } else { 949 buf->length -= ret; 950 buf->data += ret; 951 } 952 953 if (cmpxchg(&epfile->read_buffer, NULL, buf)) 954 kfree(buf); 955 956 return ret; 957 } 958 959 /* Assumes epfile->mutex is held. */ 960 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile, 961 void *data, int data_len, 962 struct iov_iter *iter) 963 { 964 struct ffs_buffer *buf; 965 966 ssize_t ret = copy_to_iter(data, data_len, iter); 967 if (data_len == ret) 968 return ret; 969 970 if (iov_iter_count(iter)) 971 return -EFAULT; 972 973 /* See ffs_copy_to_iter for more context. */ 974 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.", 975 data_len, ret); 976 977 data_len -= ret; 978 buf = kmalloc_flex(*buf, storage, data_len); 979 if (!buf) 980 return -ENOMEM; 981 buf->length = data_len; 982 buf->data = buf->storage; 983 memcpy(buf->storage, data + ret, flex_array_size(buf, storage, data_len)); 984 985 /* 986 * At this point read_buffer is NULL or READ_BUFFER_DROP (if 987 * ffs_func_eps_disable has been called in the meanwhile). See comment 988 * in struct ffs_epfile for full read_buffer pointer synchronisation 989 * story. 990 */ 991 if (cmpxchg(&epfile->read_buffer, NULL, buf)) 992 kfree(buf); 993 994 return ret; 995 } 996 997 static struct ffs_ep *ffs_epfile_wait_ep(struct ffs_epfile *epfile, struct file *file) 998 { 999 struct ffs_ep *ep; 1000 int ret; 1001 1002 /* Wait for endpoint to be enabled */ 1003 ep = epfile->ep; 1004 if (!ep) { 1005 if (file->f_flags & O_NONBLOCK) 1006 return ERR_PTR(-EAGAIN); 1007 1008 ret = wait_event_interruptible( 1009 epfile->ffs->wait, (ep = epfile->ep)); 1010 if (ret) 1011 return ERR_PTR(-EINTR); 1012 } 1013 1014 return ep; 1015 } 1016 1017 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) 1018 { 1019 struct ffs_epfile *epfile = file->private_data; 1020 struct usb_request *req; 1021 struct ffs_ep *ep; 1022 char *data = NULL; 1023 ssize_t ret, data_len = -EINVAL; 1024 int halt; 1025 bool is_rw_proxy = epfile->is_rw_proxy; 1026 1027 /* Are we still active? */ 1028 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 1029 return -ENODEV; 1030 1031 /* Proxy to base endpoint if rw_proxy */ 1032 if (is_rw_proxy) 1033 epfile = io_data->read ? epfile->epfile_out : epfile->epfile_in; 1034 1035 ep = ffs_epfile_wait_ep(epfile, file); 1036 if (IS_ERR(ep)) 1037 return PTR_ERR(ep); 1038 1039 /* Do we halt? */ 1040 halt = is_rw_proxy ? 0 : (!io_data->read == !epfile->in); 1041 if (halt && epfile->isoc) 1042 return -EINVAL; 1043 1044 /* We will be using request and read_buffer */ 1045 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK); 1046 if (ret) 1047 goto error; 1048 1049 /* Allocate & copy */ 1050 if (!halt) { 1051 struct usb_gadget *gadget; 1052 1053 /* 1054 * Do we have buffered data from previous partial read? Check 1055 * that for synchronous case only because we do not have 1056 * facility to ‘wake up’ a pending asynchronous read and push 1057 * buffered data to it which we would need to make things behave 1058 * consistently. 1059 */ 1060 if (!io_data->aio && io_data->read) { 1061 ret = __ffs_epfile_read_buffered(epfile, &io_data->data); 1062 if (ret) 1063 goto error_mutex; 1064 } 1065 1066 /* 1067 * if we _do_ wait above, the epfile->ffs->gadget might be NULL 1068 * before the waiting completes, so do not assign to 'gadget' 1069 * earlier 1070 */ 1071 gadget = epfile->ffs->gadget; 1072 1073 spin_lock_irq(&epfile->ffs->eps_lock); 1074 /* In the meantime, endpoint got disabled or changed. */ 1075 if (epfile->ep != ep) { 1076 ret = -ESHUTDOWN; 1077 goto error_lock; 1078 } 1079 data_len = iov_iter_count(&io_data->data); 1080 /* 1081 * Controller may require buffer size to be aligned to 1082 * maxpacketsize of an out endpoint. 1083 */ 1084 if (io_data->read) 1085 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len); 1086 1087 io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE; 1088 spin_unlock_irq(&epfile->ffs->eps_lock); 1089 1090 data = ffs_alloc_buffer(io_data, data_len); 1091 if (!data) { 1092 ret = -ENOMEM; 1093 goto error_mutex; 1094 } 1095 if (!io_data->read && 1096 !copy_from_iter_full(data, data_len, &io_data->data)) { 1097 ret = -EFAULT; 1098 goto error_mutex; 1099 } 1100 } 1101 1102 spin_lock_irq(&epfile->ffs->eps_lock); 1103 1104 if (epfile->ep != ep) { 1105 /* In the meantime, endpoint got disabled or changed. */ 1106 ret = -ESHUTDOWN; 1107 } else if (halt) { 1108 ret = usb_ep_set_halt(ep->ep); 1109 if (!ret) 1110 ret = -EBADMSG; 1111 } else if (data_len == -EINVAL) { 1112 /* 1113 * Sanity Check: even though data_len can't be used 1114 * uninitialized at the time I write this comment, some 1115 * compilers complain about this situation. 1116 * In order to keep the code clean from warnings, data_len is 1117 * being initialized to -EINVAL during its declaration, which 1118 * means we can't rely on compiler anymore to warn no future 1119 * changes won't result in data_len being used uninitialized. 1120 * For such reason, we're adding this redundant sanity check 1121 * here. 1122 */ 1123 WARN(1, "%s: data_len == -EINVAL\n", __func__); 1124 ret = -EINVAL; 1125 } else if (!io_data->aio) { 1126 bool interrupted = false; 1127 1128 req = ep->req; 1129 if (io_data->use_sg) { 1130 req->buf = NULL; 1131 req->sg = io_data->sgt.sgl; 1132 req->num_sgs = io_data->sgt.nents; 1133 } else { 1134 req->buf = data; 1135 req->num_sgs = 0; 1136 } 1137 1138 req->zero = !io_data->read ? epfile->zlp_enabled : 0; 1139 req->length = data_len; 1140 1141 io_data->buf = data; 1142 1143 init_completion(&io_data->done); 1144 req->context = io_data; 1145 req->complete = ffs_epfile_io_complete; 1146 1147 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 1148 if (ret < 0) 1149 goto error_lock; 1150 1151 spin_unlock_irq(&epfile->ffs->eps_lock); 1152 1153 if (wait_for_completion_interruptible(&io_data->done)) { 1154 spin_lock_irq(&epfile->ffs->eps_lock); 1155 if (epfile->ep != ep) { 1156 ret = -ESHUTDOWN; 1157 goto error_lock; 1158 } 1159 /* 1160 * To avoid race condition with ffs_epfile_io_complete, 1161 * dequeue the request first then check 1162 * status. usb_ep_dequeue API should guarantee no race 1163 * condition with req->complete callback. 1164 */ 1165 usb_ep_dequeue(ep->ep, req); 1166 spin_unlock_irq(&epfile->ffs->eps_lock); 1167 wait_for_completion(&io_data->done); 1168 interrupted = io_data->status < 0; 1169 } 1170 1171 if (interrupted) 1172 ret = -EINTR; 1173 else if (io_data->read && io_data->status > 0) 1174 ret = __ffs_epfile_read_data(epfile, data, io_data->status, 1175 &io_data->data); 1176 else 1177 ret = io_data->status; 1178 goto error_mutex; 1179 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) { 1180 ret = -ENOMEM; 1181 } else { 1182 if (io_data->use_sg) { 1183 req->buf = NULL; 1184 req->sg = io_data->sgt.sgl; 1185 req->num_sgs = io_data->sgt.nents; 1186 } else { 1187 req->buf = data; 1188 req->num_sgs = 0; 1189 } 1190 1191 req->zero = !io_data->read ? epfile->zlp_enabled : 0; 1192 req->length = data_len; 1193 1194 io_data->buf = data; 1195 io_data->ep = ep->ep; 1196 io_data->req = req; 1197 io_data->ffs = epfile->ffs; 1198 1199 req->context = io_data; 1200 req->complete = ffs_epfile_async_io_complete; 1201 1202 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 1203 if (ret) { 1204 io_data->req = NULL; 1205 usb_ep_free_request(ep->ep, req); 1206 goto error_lock; 1207 } 1208 1209 ret = -EIOCBQUEUED; 1210 /* 1211 * Do not kfree the buffer in this function. It will be freed 1212 * by ffs_user_copy_worker. 1213 */ 1214 data = NULL; 1215 } 1216 1217 error_lock: 1218 spin_unlock_irq(&epfile->ffs->eps_lock); 1219 error_mutex: 1220 mutex_unlock(&epfile->mutex); 1221 error: 1222 if (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */ 1223 ffs_free_buffer(io_data); 1224 return ret; 1225 } 1226 1227 static int 1228 ffs_epfile_open(struct inode *inode, struct file *file) 1229 { 1230 struct ffs_data *ffs = inode->i_sb->s_fs_info; 1231 struct ffs_epfile *epfile; 1232 1233 spin_lock_irq(&ffs->eps_lock); 1234 if (!ffs->opened) { 1235 spin_unlock_irq(&ffs->eps_lock); 1236 return -ENODEV; 1237 } 1238 /* 1239 * we want the state to be FFS_ACTIVE; FFS_ACTIVE alone is 1240 * not enough, though - we might have been through FFS_CLOSING 1241 * and back to FFS_ACTIVE, with our file already removed. 1242 */ 1243 epfile = smp_load_acquire(&inode->i_private); 1244 if (unlikely(ffs->state != FFS_ACTIVE || !epfile)) { 1245 spin_unlock_irq(&ffs->eps_lock); 1246 return -ENODEV; 1247 } 1248 ffs->opened++; 1249 spin_unlock_irq(&ffs->eps_lock); 1250 1251 file->private_data = epfile; 1252 return stream_open(inode, file); 1253 } 1254 1255 static int ffs_aio_cancel(struct kiocb *kiocb) 1256 { 1257 struct ffs_io_data *io_data = kiocb->private; 1258 int value; 1259 1260 if (io_data && io_data->ep && io_data->req) 1261 value = usb_ep_dequeue(io_data->ep, io_data->req); 1262 else 1263 value = -EINVAL; 1264 1265 return value; 1266 } 1267 1268 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from) 1269 { 1270 struct ffs_io_data io_data, *p = &io_data; 1271 ssize_t res; 1272 1273 if (!is_sync_kiocb(kiocb)) { 1274 p = kzalloc_obj(io_data); 1275 if (!p) 1276 return -ENOMEM; 1277 p->aio = true; 1278 } else { 1279 memset(p, 0, sizeof(*p)); 1280 p->aio = false; 1281 } 1282 1283 p->read = false; 1284 p->kiocb = kiocb; 1285 p->data = *from; 1286 p->mm = current->mm; 1287 1288 kiocb->private = p; 1289 1290 if (p->aio) { 1291 mmgrab(p->mm); 1292 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 1293 } 1294 1295 res = ffs_epfile_io(kiocb->ki_filp, p); 1296 if (res == -EIOCBQUEUED) 1297 return res; 1298 if (p->aio) { 1299 kiocb->ki_complete(kiocb, res); 1300 mmdrop(p->mm); 1301 kfree(p); 1302 return -EIOCBQUEUED; 1303 } else { 1304 *from = p->data; 1305 } 1306 return res; 1307 } 1308 1309 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) 1310 { 1311 struct ffs_io_data io_data, *p = &io_data; 1312 ssize_t res; 1313 1314 if (!is_sync_kiocb(kiocb)) { 1315 p = kzalloc_obj(io_data); 1316 if (!p) 1317 return -ENOMEM; 1318 p->aio = true; 1319 } else { 1320 memset(p, 0, sizeof(*p)); 1321 p->aio = false; 1322 } 1323 1324 p->read = true; 1325 p->kiocb = kiocb; 1326 if (p->aio) { 1327 p->to_free = dup_iter(&p->data, to, GFP_KERNEL); 1328 if (!iter_is_ubuf(&p->data) && !p->to_free) { 1329 kfree(p); 1330 return -ENOMEM; 1331 } 1332 } else { 1333 p->data = *to; 1334 p->to_free = NULL; 1335 } 1336 p->mm = current->mm; 1337 1338 kiocb->private = p; 1339 1340 if (p->aio) { 1341 mmgrab(p->mm); 1342 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 1343 } 1344 1345 res = ffs_epfile_io(kiocb->ki_filp, p); 1346 if (res == -EIOCBQUEUED) 1347 return res; 1348 1349 if (p->aio) { 1350 kiocb->ki_complete(kiocb, res); 1351 mmdrop(p->mm); 1352 kfree(p->to_free); 1353 kfree(p); 1354 return -EIOCBQUEUED; 1355 } else { 1356 *to = p->data; 1357 } 1358 return res; 1359 } 1360 1361 static void ffs_dmabuf_release(struct kref *ref) 1362 { 1363 struct ffs_dmabuf_priv *priv = container_of(ref, struct ffs_dmabuf_priv, ref); 1364 struct dma_buf_attachment *attach = priv->attach; 1365 struct dma_buf *dmabuf = attach->dmabuf; 1366 1367 pr_vdebug("FFS DMABUF release\n"); 1368 dma_buf_unmap_attachment_unlocked(attach, priv->sgt, priv->dir); 1369 1370 dma_buf_detach(attach->dmabuf, attach); 1371 dma_buf_put(dmabuf); 1372 kfree(priv); 1373 } 1374 1375 static void ffs_dmabuf_get(struct dma_buf_attachment *attach) 1376 { 1377 struct ffs_dmabuf_priv *priv = attach->importer_priv; 1378 1379 kref_get(&priv->ref); 1380 } 1381 1382 static void ffs_dmabuf_put(struct dma_buf_attachment *attach) 1383 { 1384 struct ffs_dmabuf_priv *priv = attach->importer_priv; 1385 1386 kref_put(&priv->ref, ffs_dmabuf_release); 1387 } 1388 1389 static int 1390 ffs_epfile_release(struct inode *inode, struct file *file) 1391 { 1392 struct ffs_epfile *epfile = file->private_data; 1393 struct ffs_dmabuf_priv *priv, *tmp; 1394 struct ffs_data *ffs = epfile->ffs; 1395 1396 mutex_lock(&epfile->dmabufs_mutex); 1397 1398 /* Close all attached DMABUFs */ 1399 list_for_each_entry_safe(priv, tmp, &epfile->dmabufs, entry) { 1400 /* Cancel any pending transfer */ 1401 spin_lock_irq(&ffs->eps_lock); 1402 if (priv->ep && priv->req) 1403 usb_ep_dequeue(priv->ep, priv->req); 1404 spin_unlock_irq(&ffs->eps_lock); 1405 1406 list_del(&priv->entry); 1407 ffs_dmabuf_put(priv->attach); 1408 } 1409 1410 mutex_unlock(&epfile->dmabufs_mutex); 1411 1412 ffs_data_closed(epfile->ffs); 1413 1414 return 0; 1415 } 1416 1417 static void ffs_dmabuf_cleanup(struct work_struct *work) 1418 { 1419 struct ffs_dma_fence *dma_fence = 1420 container_of(work, struct ffs_dma_fence, work); 1421 struct ffs_dmabuf_priv *priv = dma_fence->priv; 1422 struct dma_buf_attachment *attach = priv->attach; 1423 struct dma_fence *fence = &dma_fence->base; 1424 struct usb_request *req = dma_fence->req; 1425 struct usb_ep *ep = dma_fence->ep; 1426 1427 /* 1428 * eps_lock pairs with the cancel paths so they cannot pass a freed 1429 * req to usb_ep_dequeue(). Only clear if priv->req still names ours; 1430 * a re-queue on the same attachment may have taken that slot. 1431 */ 1432 spin_lock_irq(&priv->ffs->eps_lock); 1433 if (priv->req == req) 1434 priv->req = NULL; 1435 spin_unlock_irq(&priv->ffs->eps_lock); 1436 1437 if (ep && req) 1438 usb_ep_free_request(ep, req); 1439 1440 ffs_dmabuf_put(attach); 1441 dma_fence_put(fence); 1442 } 1443 1444 static void ffs_dmabuf_signal_done(struct ffs_dma_fence *dma_fence, int ret) 1445 { 1446 struct ffs_dmabuf_priv *priv = dma_fence->priv; 1447 struct dma_fence *fence = &dma_fence->base; 1448 bool cookie = dma_fence_begin_signalling(); 1449 1450 dma_fence_get(fence); 1451 fence->error = ret; 1452 dma_fence_signal(fence); 1453 dma_fence_end_signalling(cookie); 1454 1455 /* 1456 * The fence will be unref'd in ffs_dmabuf_cleanup. 1457 * It can't be done here, as the unref functions might try to lock 1458 * the resv object, which would deadlock. 1459 */ 1460 INIT_WORK(&dma_fence->work, ffs_dmabuf_cleanup); 1461 queue_work(priv->ffs->io_completion_wq, &dma_fence->work); 1462 } 1463 1464 static void ffs_epfile_dmabuf_io_complete(struct usb_ep *ep, 1465 struct usb_request *req) 1466 { 1467 pr_vdebug("FFS: DMABUF transfer complete, status=%d\n", req->status); 1468 /* req is freed by ffs_dmabuf_cleanup() under eps_lock. */ 1469 ffs_dmabuf_signal_done(req->context, req->status); 1470 } 1471 1472 static const char *ffs_dmabuf_get_driver_name(struct dma_fence *fence) 1473 { 1474 return "functionfs"; 1475 } 1476 1477 static const char *ffs_dmabuf_get_timeline_name(struct dma_fence *fence) 1478 { 1479 return ""; 1480 } 1481 1482 static void ffs_dmabuf_fence_release(struct dma_fence *fence) 1483 { 1484 struct ffs_dma_fence *dma_fence = 1485 container_of(fence, struct ffs_dma_fence, base); 1486 1487 kfree(dma_fence); 1488 } 1489 1490 static const struct dma_fence_ops ffs_dmabuf_fence_ops = { 1491 .get_driver_name = ffs_dmabuf_get_driver_name, 1492 .get_timeline_name = ffs_dmabuf_get_timeline_name, 1493 .release = ffs_dmabuf_fence_release, 1494 }; 1495 1496 static int ffs_dma_resv_lock(struct dma_buf *dmabuf, bool nonblock) 1497 { 1498 if (!nonblock) 1499 return dma_resv_lock_interruptible(dmabuf->resv, NULL); 1500 1501 if (!dma_resv_trylock(dmabuf->resv)) 1502 return -EBUSY; 1503 1504 return 0; 1505 } 1506 1507 static struct dma_buf_attachment * 1508 ffs_dmabuf_find_attachment(struct ffs_epfile *epfile, struct dma_buf *dmabuf) 1509 { 1510 struct device *dev = epfile->ffs->gadget->dev.parent; 1511 struct dma_buf_attachment *attach = NULL; 1512 struct ffs_dmabuf_priv *priv; 1513 1514 mutex_lock(&epfile->dmabufs_mutex); 1515 1516 list_for_each_entry(priv, &epfile->dmabufs, entry) { 1517 if (priv->attach->dev == dev 1518 && priv->attach->dmabuf == dmabuf) { 1519 attach = priv->attach; 1520 break; 1521 } 1522 } 1523 1524 if (attach) 1525 ffs_dmabuf_get(attach); 1526 1527 mutex_unlock(&epfile->dmabufs_mutex); 1528 1529 return attach ?: ERR_PTR(-EPERM); 1530 } 1531 1532 static int ffs_dmabuf_attach(struct file *file, int fd) 1533 { 1534 bool nonblock = file->f_flags & O_NONBLOCK; 1535 struct ffs_epfile *epfile = file->private_data; 1536 struct usb_gadget *gadget = epfile->ffs->gadget; 1537 struct dma_buf_attachment *attach; 1538 struct ffs_dmabuf_priv *priv; 1539 enum dma_data_direction dir; 1540 struct sg_table *sg_table; 1541 struct dma_buf *dmabuf; 1542 int err; 1543 1544 if (!gadget || !gadget->sg_supported) 1545 return -EPERM; 1546 1547 dmabuf = dma_buf_get(fd); 1548 if (IS_ERR(dmabuf)) 1549 return PTR_ERR(dmabuf); 1550 1551 attach = dma_buf_attach(dmabuf, gadget->dev.parent); 1552 if (IS_ERR(attach)) { 1553 err = PTR_ERR(attach); 1554 goto err_dmabuf_put; 1555 } 1556 1557 priv = kzalloc_obj(*priv); 1558 if (!priv) { 1559 err = -ENOMEM; 1560 goto err_dmabuf_detach; 1561 } 1562 1563 dir = epfile->in ? DMA_TO_DEVICE : DMA_FROM_DEVICE; 1564 1565 err = ffs_dma_resv_lock(dmabuf, nonblock); 1566 if (err) 1567 goto err_free_priv; 1568 1569 sg_table = dma_buf_map_attachment(attach, dir); 1570 dma_resv_unlock(dmabuf->resv); 1571 1572 if (IS_ERR(sg_table)) { 1573 err = PTR_ERR(sg_table); 1574 goto err_free_priv; 1575 } 1576 1577 attach->importer_priv = priv; 1578 1579 priv->sgt = sg_table; 1580 priv->dir = dir; 1581 priv->ffs = epfile->ffs; 1582 priv->attach = attach; 1583 spin_lock_init(&priv->lock); 1584 kref_init(&priv->ref); 1585 priv->context = dma_fence_context_alloc(1); 1586 1587 mutex_lock(&epfile->dmabufs_mutex); 1588 list_add(&priv->entry, &epfile->dmabufs); 1589 mutex_unlock(&epfile->dmabufs_mutex); 1590 1591 return 0; 1592 1593 err_free_priv: 1594 kfree(priv); 1595 err_dmabuf_detach: 1596 dma_buf_detach(dmabuf, attach); 1597 err_dmabuf_put: 1598 dma_buf_put(dmabuf); 1599 1600 return err; 1601 } 1602 1603 static int ffs_dmabuf_detach(struct file *file, int fd) 1604 { 1605 struct ffs_epfile *epfile = file->private_data; 1606 struct ffs_data *ffs = epfile->ffs; 1607 struct device *dev = ffs->gadget->dev.parent; 1608 struct ffs_dmabuf_priv *priv, *tmp; 1609 struct dma_buf *dmabuf; 1610 int ret = -EPERM; 1611 1612 dmabuf = dma_buf_get(fd); 1613 if (IS_ERR(dmabuf)) 1614 return PTR_ERR(dmabuf); 1615 1616 mutex_lock(&epfile->dmabufs_mutex); 1617 1618 list_for_each_entry_safe(priv, tmp, &epfile->dmabufs, entry) { 1619 if (priv->attach->dev == dev 1620 && priv->attach->dmabuf == dmabuf) { 1621 /* Cancel any pending transfer */ 1622 spin_lock_irq(&ffs->eps_lock); 1623 if (priv->ep && priv->req) 1624 usb_ep_dequeue(priv->ep, priv->req); 1625 spin_unlock_irq(&ffs->eps_lock); 1626 1627 list_del(&priv->entry); 1628 1629 /* Unref the reference from ffs_dmabuf_attach() */ 1630 ffs_dmabuf_put(priv->attach); 1631 ret = 0; 1632 break; 1633 } 1634 } 1635 1636 mutex_unlock(&epfile->dmabufs_mutex); 1637 dma_buf_put(dmabuf); 1638 1639 return ret; 1640 } 1641 1642 static int ffs_dmabuf_transfer(struct file *file, 1643 const struct usb_ffs_dmabuf_transfer_req *req) 1644 { 1645 bool nonblock = file->f_flags & O_NONBLOCK; 1646 struct ffs_epfile *epfile = file->private_data; 1647 struct dma_buf_attachment *attach; 1648 struct ffs_dmabuf_priv *priv; 1649 struct ffs_dma_fence *fence; 1650 struct usb_request *usb_req; 1651 enum dma_resv_usage resv_dir; 1652 struct dma_buf *dmabuf; 1653 unsigned long timeout; 1654 struct ffs_ep *ep; 1655 bool cookie; 1656 u32 seqno; 1657 long retl; 1658 int ret; 1659 1660 if (req->flags & ~USB_FFS_DMABUF_TRANSFER_MASK) 1661 return -EINVAL; 1662 1663 dmabuf = dma_buf_get(req->fd); 1664 if (IS_ERR(dmabuf)) 1665 return PTR_ERR(dmabuf); 1666 1667 if (req->length > dmabuf->size || req->length == 0) { 1668 ret = -EINVAL; 1669 goto err_dmabuf_put; 1670 } 1671 1672 attach = ffs_dmabuf_find_attachment(epfile, dmabuf); 1673 if (IS_ERR(attach)) { 1674 ret = PTR_ERR(attach); 1675 goto err_dmabuf_put; 1676 } 1677 1678 priv = attach->importer_priv; 1679 1680 ep = ffs_epfile_wait_ep(epfile, file); 1681 if (IS_ERR(ep)) { 1682 ret = PTR_ERR(ep); 1683 goto err_attachment_put; 1684 } 1685 1686 ret = ffs_dma_resv_lock(dmabuf, nonblock); 1687 if (ret) 1688 goto err_attachment_put; 1689 1690 /* Make sure we don't have writers */ 1691 timeout = nonblock ? 0 : msecs_to_jiffies(DMABUF_ENQUEUE_TIMEOUT_MS); 1692 retl = dma_resv_wait_timeout(dmabuf->resv, 1693 dma_resv_usage_rw(!epfile->in), 1694 true, timeout); 1695 if (retl == 0) 1696 retl = -EBUSY; 1697 if (retl < 0) { 1698 ret = (int)retl; 1699 goto err_resv_unlock; 1700 } 1701 1702 ret = dma_resv_reserve_fences(dmabuf->resv, 1); 1703 if (ret) 1704 goto err_resv_unlock; 1705 1706 fence = kmalloc_obj(*fence); 1707 if (!fence) { 1708 ret = -ENOMEM; 1709 goto err_resv_unlock; 1710 } 1711 1712 fence->priv = priv; 1713 1714 spin_lock_irq(&epfile->ffs->eps_lock); 1715 1716 /* In the meantime, endpoint got disabled or changed. */ 1717 if (epfile->ep != ep) { 1718 ret = -ESHUTDOWN; 1719 goto err_fence_free; 1720 } 1721 1722 usb_req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC); 1723 if (!usb_req) { 1724 ret = -ENOMEM; 1725 goto err_fence_free; 1726 } 1727 1728 /* 1729 * usb_ep_queue() guarantees that all transfers are processed in the 1730 * order they are enqueued, so we can use a simple incrementing 1731 * sequence number for the dma_fence. 1732 */ 1733 seqno = atomic_add_return(1, &epfile->seqno); 1734 1735 dma_fence_init(&fence->base, &ffs_dmabuf_fence_ops, 1736 &priv->lock, priv->context, seqno); 1737 1738 resv_dir = epfile->in ? DMA_RESV_USAGE_READ : DMA_RESV_USAGE_WRITE; 1739 1740 dma_resv_add_fence(dmabuf->resv, &fence->base, resv_dir); 1741 dma_fence_put(&fence->base); 1742 dma_resv_unlock(dmabuf->resv); 1743 1744 /* Now that the dma_fence is in place, queue the transfer. */ 1745 1746 usb_req->zero = epfile->zlp_enabled; 1747 usb_req->length = req->length; 1748 usb_req->buf = NULL; 1749 usb_req->sg = priv->sgt->sgl; 1750 usb_req->num_sgs = sg_nents_for_len(priv->sgt->sgl, req->length); 1751 usb_req->sg_was_mapped = true; 1752 usb_req->context = fence; 1753 usb_req->complete = ffs_epfile_dmabuf_io_complete; 1754 1755 /* ffs_dmabuf_cleanup() frees usb_req via these two fields. */ 1756 fence->req = usb_req; 1757 fence->ep = ep->ep; 1758 1759 cookie = dma_fence_begin_signalling(); 1760 ret = usb_ep_queue(ep->ep, usb_req, GFP_ATOMIC); 1761 dma_fence_end_signalling(cookie); 1762 if (!ret) { 1763 priv->req = usb_req; 1764 priv->ep = ep->ep; 1765 } else { 1766 pr_warn("FFS: Failed to queue DMABUF: %d\n", ret); 1767 ffs_dmabuf_signal_done(fence, ret); 1768 } 1769 1770 spin_unlock_irq(&epfile->ffs->eps_lock); 1771 dma_buf_put(dmabuf); 1772 1773 return ret; 1774 1775 err_fence_free: 1776 spin_unlock_irq(&epfile->ffs->eps_lock); 1777 kfree(fence); 1778 err_resv_unlock: 1779 dma_resv_unlock(dmabuf->resv); 1780 err_attachment_put: 1781 ffs_dmabuf_put(attach); 1782 err_dmabuf_put: 1783 dma_buf_put(dmabuf); 1784 1785 return ret; 1786 } 1787 1788 static long ffs_epfile_ioctl(struct file *file, unsigned code, 1789 unsigned long value) 1790 { 1791 struct ffs_epfile *epfile = file->private_data; 1792 struct ffs_ep *ep; 1793 int ret; 1794 __u32 enable_zlp = 0; 1795 1796 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 1797 return -ENODEV; 1798 1799 if (epfile->is_rw_proxy) 1800 return -ENOTTY; 1801 1802 switch (code) { 1803 case FUNCTIONFS_DMABUF_ATTACH: 1804 { 1805 int fd; 1806 1807 if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) 1808 return -EFAULT; 1809 1810 return ffs_dmabuf_attach(file, fd); 1811 } 1812 case FUNCTIONFS_DMABUF_DETACH: 1813 { 1814 int fd; 1815 1816 if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) 1817 return -EFAULT; 1818 1819 return ffs_dmabuf_detach(file, fd); 1820 } 1821 case FUNCTIONFS_DMABUF_TRANSFER: 1822 { 1823 struct usb_ffs_dmabuf_transfer_req req; 1824 1825 if (copy_from_user(&req, (void __user *)value, sizeof(req))) 1826 return -EFAULT; 1827 1828 return ffs_dmabuf_transfer(file, &req); 1829 } 1830 /* 1831 * We handle this IOCTL before ffs_epfile_wait_ep() to allow userspace 1832 * to configure ZLP behavior immediately without blocking indefinitely 1833 * while waiting for the USB host to connect and enable the endpoint. 1834 */ 1835 case FUNCTIONFS_ENDPOINT_ENABLE_ZLP: 1836 if (!epfile->in) 1837 return -EINVAL; 1838 1839 if (copy_from_user(&enable_zlp, (void __user *)value, sizeof(enable_zlp))) 1840 return -EFAULT; 1841 1842 spin_lock_irq(&epfile->ffs->eps_lock); 1843 epfile->zlp_enabled = !!enable_zlp; 1844 spin_unlock_irq(&epfile->ffs->eps_lock); 1845 1846 return 0; 1847 default: 1848 break; 1849 } 1850 1851 /* Wait for endpoint to be enabled */ 1852 ep = ffs_epfile_wait_ep(epfile, file); 1853 if (IS_ERR(ep)) 1854 return PTR_ERR(ep); 1855 1856 spin_lock_irq(&epfile->ffs->eps_lock); 1857 1858 /* In the meantime, endpoint got disabled or changed. */ 1859 if (epfile->ep != ep) { 1860 spin_unlock_irq(&epfile->ffs->eps_lock); 1861 return -ESHUTDOWN; 1862 } 1863 1864 switch (code) { 1865 case FUNCTIONFS_FIFO_STATUS: 1866 ret = usb_ep_fifo_status(epfile->ep->ep); 1867 break; 1868 case FUNCTIONFS_FIFO_FLUSH: 1869 usb_ep_fifo_flush(epfile->ep->ep); 1870 ret = 0; 1871 break; 1872 case FUNCTIONFS_CLEAR_HALT: 1873 ret = usb_ep_clear_halt(epfile->ep->ep); 1874 break; 1875 case FUNCTIONFS_ENDPOINT_REVMAP: 1876 ret = epfile->ep->num; 1877 break; 1878 case FUNCTIONFS_ENDPOINT_DESC: 1879 { 1880 const struct usb_endpoint_descriptor *desc; 1881 struct usb_endpoint_descriptor desc1; 1882 int desc_idx; 1883 1884 switch (epfile->ffs->gadget->speed) { 1885 case USB_SPEED_SUPER: 1886 case USB_SPEED_SUPER_PLUS: 1887 desc_idx = 2; 1888 break; 1889 case USB_SPEED_HIGH: 1890 desc_idx = 1; 1891 break; 1892 default: 1893 desc_idx = 0; 1894 } 1895 1896 do { 1897 desc = epfile->ep->descs[desc_idx]; 1898 } while (!desc && --desc_idx >= 0); 1899 1900 if (!desc) 1901 desc = epfile->ep->ep->desc; 1902 if (!desc) { 1903 ret = -EINVAL; 1904 break; 1905 } 1906 1907 memcpy(&desc1, desc, desc->bLength); 1908 1909 spin_unlock_irq(&epfile->ffs->eps_lock); 1910 ret = copy_to_user((void __user *)value, &desc1, desc1.bLength); 1911 if (ret) 1912 ret = -EFAULT; 1913 return ret; 1914 } 1915 default: 1916 ret = -ENOTTY; 1917 } 1918 spin_unlock_irq(&epfile->ffs->eps_lock); 1919 1920 return ret; 1921 } 1922 1923 static const struct file_operations ffs_epfile_operations = { 1924 1925 .open = ffs_epfile_open, 1926 .write_iter = ffs_epfile_write_iter, 1927 .read_iter = ffs_epfile_read_iter, 1928 .release = ffs_epfile_release, 1929 .unlocked_ioctl = ffs_epfile_ioctl, 1930 .compat_ioctl = compat_ptr_ioctl, 1931 }; 1932 1933 1934 /* File system and super block operations ***********************************/ 1935 1936 /* 1937 * Mounting the file system creates a controller file, used first for 1938 * function configuration then later for event monitoring. 1939 */ 1940 1941 static struct inode *__must_check 1942 ffs_sb_make_inode(struct super_block *sb, void *data, 1943 const struct file_operations *fops, 1944 const struct inode_operations *iops, 1945 struct ffs_file_perms *perms) 1946 { 1947 struct inode *inode; 1948 1949 inode = new_inode(sb); 1950 1951 if (inode) { 1952 struct timespec64 ts = inode_set_ctime_current(inode); 1953 1954 inode->i_ino = get_next_ino(); 1955 inode->i_mode = perms->mode; 1956 inode->i_uid = perms->uid; 1957 inode->i_gid = perms->gid; 1958 inode_set_atime_to_ts(inode, ts); 1959 inode_set_mtime_to_ts(inode, ts); 1960 inode->i_private = data; 1961 if (fops) 1962 inode->i_fop = fops; 1963 if (iops) 1964 inode->i_op = iops; 1965 } 1966 1967 return inode; 1968 } 1969 1970 /* Create "regular" file */ 1971 static int ffs_sb_create_file(struct super_block *sb, const char *name, 1972 void *data, const struct file_operations *fops) 1973 { 1974 struct ffs_data *ffs = sb->s_fs_info; 1975 struct dentry *dentry; 1976 struct inode *inode; 1977 1978 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms); 1979 if (!inode) 1980 return -ENOMEM; 1981 dentry = simple_start_creating(sb->s_root, name); 1982 if (IS_ERR(dentry)) { 1983 iput(inode); 1984 return PTR_ERR(dentry); 1985 } 1986 1987 d_make_persistent(dentry, inode); 1988 1989 simple_done_creating(dentry); 1990 return 0; 1991 } 1992 1993 /* Super block */ 1994 static const struct super_operations ffs_sb_operations = { 1995 .statfs = simple_statfs, 1996 .drop_inode = inode_just_drop, 1997 }; 1998 1999 struct ffs_sb_fill_data { 2000 struct ffs_file_perms perms; 2001 umode_t root_mode; 2002 const char *dev_name; 2003 bool no_disconnect; 2004 struct ffs_data *ffs_data; 2005 }; 2006 2007 static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc) 2008 { 2009 struct ffs_sb_fill_data *data = fc->fs_private; 2010 struct inode *inode; 2011 struct ffs_data *ffs = data->ffs_data; 2012 2013 ffs->sb = sb; 2014 data->ffs_data = NULL; 2015 sb->s_fs_info = ffs; 2016 sb->s_blocksize = PAGE_SIZE; 2017 sb->s_blocksize_bits = PAGE_SHIFT; 2018 sb->s_magic = FUNCTIONFS_MAGIC; 2019 sb->s_op = &ffs_sb_operations; 2020 sb->s_time_gran = 1; 2021 2022 /* Root inode */ 2023 data->perms.mode = data->root_mode; 2024 inode = ffs_sb_make_inode(sb, NULL, 2025 &simple_dir_operations, 2026 &simple_dir_inode_operations, 2027 &data->perms); 2028 sb->s_root = d_make_root(inode); 2029 if (!sb->s_root) 2030 return -ENOMEM; 2031 2032 /* EP0 file */ 2033 return ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations); 2034 } 2035 2036 enum { 2037 Opt_no_disconnect, 2038 Opt_rmode, 2039 Opt_fmode, 2040 Opt_mode, 2041 Opt_uid, 2042 Opt_gid, 2043 }; 2044 2045 static const struct fs_parameter_spec ffs_fs_fs_parameters[] = { 2046 fsparam_bool ("no_disconnect", Opt_no_disconnect), 2047 fsparam_u32 ("rmode", Opt_rmode), 2048 fsparam_u32 ("fmode", Opt_fmode), 2049 fsparam_u32 ("mode", Opt_mode), 2050 fsparam_u32 ("uid", Opt_uid), 2051 fsparam_u32 ("gid", Opt_gid), 2052 {} 2053 }; 2054 2055 static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param) 2056 { 2057 struct ffs_sb_fill_data *data = fc->fs_private; 2058 struct fs_parse_result result; 2059 int opt; 2060 2061 opt = fs_parse(fc, ffs_fs_fs_parameters, param, &result); 2062 if (opt < 0) 2063 return opt; 2064 2065 switch (opt) { 2066 case Opt_no_disconnect: 2067 data->no_disconnect = result.boolean; 2068 break; 2069 case Opt_rmode: 2070 data->root_mode = (result.uint_32 & 0555) | S_IFDIR; 2071 break; 2072 case Opt_fmode: 2073 data->perms.mode = (result.uint_32 & 0666) | S_IFREG; 2074 break; 2075 case Opt_mode: 2076 data->root_mode = (result.uint_32 & 0555) | S_IFDIR; 2077 data->perms.mode = (result.uint_32 & 0666) | S_IFREG; 2078 break; 2079 2080 case Opt_uid: 2081 data->perms.uid = make_kuid(current_user_ns(), result.uint_32); 2082 if (!uid_valid(data->perms.uid)) 2083 goto unmapped_value; 2084 break; 2085 case Opt_gid: 2086 data->perms.gid = make_kgid(current_user_ns(), result.uint_32); 2087 if (!gid_valid(data->perms.gid)) 2088 goto unmapped_value; 2089 break; 2090 2091 default: 2092 return -ENOPARAM; 2093 } 2094 2095 return 0; 2096 2097 unmapped_value: 2098 return invalf(fc, "%s: unmapped value: %u", param->key, result.uint_32); 2099 } 2100 2101 /* 2102 * Set up the superblock for a mount. 2103 */ 2104 static int ffs_fs_get_tree(struct fs_context *fc) 2105 { 2106 struct ffs_sb_fill_data *ctx = fc->fs_private; 2107 struct ffs_data *ffs; 2108 int ret; 2109 2110 if (!fc->source) 2111 return invalf(fc, "No source specified"); 2112 2113 ffs = ffs_data_new(fc->source); 2114 if (!ffs) 2115 return -ENOMEM; 2116 ffs->file_perms = ctx->perms; 2117 ffs->no_disconnect = ctx->no_disconnect; 2118 2119 ffs->dev_name = kstrdup(fc->source, GFP_KERNEL); 2120 if (!ffs->dev_name) { 2121 ffs_data_put(ffs); 2122 return -ENOMEM; 2123 } 2124 2125 ret = ffs_acquire_dev(ffs->dev_name, ffs); 2126 if (ret) { 2127 ffs_data_put(ffs); 2128 return ret; 2129 } 2130 2131 ctx->ffs_data = ffs; 2132 return get_tree_nodev(fc, ffs_sb_fill); 2133 } 2134 2135 static void ffs_fs_free_fc(struct fs_context *fc) 2136 { 2137 struct ffs_sb_fill_data *ctx = fc->fs_private; 2138 2139 if (ctx) { 2140 if (ctx->ffs_data) { 2141 ffs_data_put(ctx->ffs_data); 2142 } 2143 2144 kfree(ctx); 2145 } 2146 } 2147 2148 static const struct fs_context_operations ffs_fs_context_ops = { 2149 .free = ffs_fs_free_fc, 2150 .parse_param = ffs_fs_parse_param, 2151 .get_tree = ffs_fs_get_tree, 2152 }; 2153 2154 static int ffs_fs_init_fs_context(struct fs_context *fc) 2155 { 2156 struct ffs_sb_fill_data *ctx; 2157 2158 ctx = kzalloc_obj(struct ffs_sb_fill_data); 2159 if (!ctx) 2160 return -ENOMEM; 2161 2162 ctx->perms.mode = S_IFREG | 0600; 2163 ctx->perms.uid = GLOBAL_ROOT_UID; 2164 ctx->perms.gid = GLOBAL_ROOT_GID; 2165 ctx->root_mode = S_IFDIR | 0500; 2166 ctx->no_disconnect = false; 2167 2168 fc->fs_private = ctx; 2169 fc->ops = &ffs_fs_context_ops; 2170 return 0; 2171 } 2172 2173 static void 2174 ffs_fs_kill_sb(struct super_block *sb) 2175 { 2176 kill_anon_super(sb); 2177 if (sb->s_fs_info) { 2178 struct ffs_data *ffs = sb->s_fs_info; 2179 ffs->state = FFS_CLOSING; 2180 ffs_data_reset(ffs); 2181 // no configfs accesses from that point on, 2182 // so no further schedule_work() is possible 2183 cancel_work_sync(&ffs->reset_work); 2184 ffs_data_put(ffs); 2185 } 2186 } 2187 2188 static struct file_system_type ffs_fs_type = { 2189 .owner = THIS_MODULE, 2190 .name = "functionfs", 2191 .init_fs_context = ffs_fs_init_fs_context, 2192 .parameters = ffs_fs_fs_parameters, 2193 .kill_sb = ffs_fs_kill_sb, 2194 }; 2195 MODULE_ALIAS_FS("functionfs"); 2196 2197 2198 /* Driver's main init/cleanup functions *************************************/ 2199 2200 static int functionfs_init(void) 2201 { 2202 int ret; 2203 2204 ret = register_filesystem(&ffs_fs_type); 2205 if (!ret) 2206 pr_info("file system registered\n"); 2207 else 2208 pr_err("failed registering file system (%d)\n", ret); 2209 2210 return ret; 2211 } 2212 2213 static void functionfs_cleanup(void) 2214 { 2215 pr_info("unloading\n"); 2216 unregister_filesystem(&ffs_fs_type); 2217 } 2218 2219 2220 /* ffs_data and ffs_function construction and destruction code **************/ 2221 2222 static void ffs_data_clear(struct ffs_data *ffs); 2223 2224 static void ffs_data_get(struct ffs_data *ffs) 2225 { 2226 refcount_inc(&ffs->ref); 2227 } 2228 2229 static void ffs_data_put(struct ffs_data *ffs) 2230 { 2231 if (refcount_dec_and_test(&ffs->ref)) { 2232 pr_info("%s(): freeing\n", __func__); 2233 ffs_data_clear(ffs); 2234 ffs_release_dev(ffs->private_data); 2235 BUG_ON(waitqueue_active(&ffs->ev.waitq) || 2236 swait_active(&ffs->ep0req_completion.wait) || 2237 waitqueue_active(&ffs->wait)); 2238 destroy_workqueue(ffs->io_completion_wq); 2239 kfree(ffs->dev_name); 2240 kfree(ffs); 2241 } 2242 } 2243 2244 static void ffs_data_closed(struct ffs_data *ffs) 2245 { 2246 spin_lock_irq(&ffs->eps_lock); 2247 if (--ffs->opened) { // not the last opener? 2248 spin_unlock_irq(&ffs->eps_lock); 2249 return; 2250 } 2251 if (ffs->no_disconnect) { 2252 struct ffs_epfile *epfiles; 2253 2254 ffs->state = FFS_DEACTIVATED; 2255 epfiles = ffs->epfiles; 2256 ffs->epfiles = NULL; 2257 spin_unlock_irq(&ffs->eps_lock); 2258 2259 if (epfiles) 2260 ffs_epfiles_destroy(ffs->sb, epfiles, 2261 ffs->epfiles_count); 2262 2263 if (ffs->setup_state == FFS_SETUP_PENDING) 2264 __ffs_ep0_stall(ffs); 2265 } else { 2266 ffs->state = FFS_CLOSING; 2267 spin_unlock_irq(&ffs->eps_lock); 2268 ffs_data_reset(ffs); 2269 } 2270 } 2271 2272 static struct ffs_data *ffs_data_new(const char *dev_name) 2273 { 2274 struct ffs_data *ffs = kzalloc_obj(*ffs); 2275 if (!ffs) 2276 return NULL; 2277 2278 ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name); 2279 if (!ffs->io_completion_wq) { 2280 kfree(ffs); 2281 return NULL; 2282 } 2283 2284 refcount_set(&ffs->ref, 1); 2285 ffs->opened = 0; 2286 ffs->state = FFS_READ_DESCRIPTORS; 2287 mutex_init(&ffs->mutex); 2288 spin_lock_init(&ffs->eps_lock); 2289 init_waitqueue_head(&ffs->ev.waitq); 2290 init_waitqueue_head(&ffs->wait); 2291 init_completion(&ffs->ep0req_completion); 2292 INIT_WORK(&ffs->reset_work, ffs_reset_work); 2293 2294 /* XXX REVISIT need to update it in some places, or do we? */ 2295 ffs->ev.can_stall = 1; 2296 2297 return ffs; 2298 } 2299 2300 static void ffs_data_clear(struct ffs_data *ffs) 2301 { 2302 struct ffs_epfile *epfiles; 2303 unsigned long flags; 2304 2305 ffs_closed(ffs); 2306 2307 BUG_ON(ffs->gadget); 2308 2309 spin_lock_irqsave(&ffs->eps_lock, flags); 2310 epfiles = ffs->epfiles; 2311 ffs->epfiles = NULL; 2312 spin_unlock_irqrestore(&ffs->eps_lock, flags); 2313 2314 /* 2315 * potential race possible between ffs_func_eps_disable 2316 * & ffs_epfile_release therefore maintaining a local 2317 * copy of epfile will save us from use-after-free. 2318 */ 2319 if (epfiles) { 2320 ffs_epfiles_destroy(ffs->sb, epfiles, ffs->epfiles_count); 2321 ffs->epfiles = NULL; 2322 } 2323 2324 if (ffs->ffs_eventfd) { 2325 eventfd_ctx_put(ffs->ffs_eventfd); 2326 ffs->ffs_eventfd = NULL; 2327 } 2328 2329 kfree(ffs->raw_descs_data); 2330 kfree(ffs->raw_strings); 2331 kfree(ffs->stringtabs); 2332 } 2333 2334 static void ffs_data_reset(struct ffs_data *ffs) 2335 { 2336 ffs_data_clear(ffs); 2337 2338 spin_lock_irq(&ffs->eps_lock); 2339 ffs->raw_descs_data = NULL; 2340 ffs->raw_descs = NULL; 2341 ffs->raw_strings = NULL; 2342 ffs->stringtabs = NULL; 2343 2344 ffs->raw_descs_length = 0; 2345 ffs->fs_descs_count = 0; 2346 ffs->hs_descs_count = 0; 2347 ffs->ss_descs_count = 0; 2348 2349 ffs->strings_count = 0; 2350 ffs->interfaces_count = 0; 2351 ffs->eps_count = 0; 2352 2353 ffs->ev.count = 0; 2354 2355 ffs->state = FFS_READ_DESCRIPTORS; 2356 ffs->setup_state = FFS_NO_SETUP; 2357 ffs->flags = 0; 2358 2359 ffs->ms_os_descs_ext_prop_count = 0; 2360 ffs->ms_os_descs_ext_prop_name_len = 0; 2361 ffs->ms_os_descs_ext_prop_data_len = 0; 2362 spin_unlock_irq(&ffs->eps_lock); 2363 } 2364 2365 2366 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) 2367 { 2368 struct usb_gadget_strings **lang; 2369 int first_id; 2370 2371 if ((ffs->state != FFS_ACTIVE 2372 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags))) 2373 return -EBADFD; 2374 2375 first_id = usb_string_ids_n(cdev, ffs->strings_count); 2376 if (first_id < 0) 2377 return first_id; 2378 2379 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); 2380 if (!ffs->ep0req) 2381 return -ENOMEM; 2382 ffs->ep0req->complete = ffs_ep0_complete; 2383 ffs->ep0req->context = ffs; 2384 2385 lang = ffs->stringtabs; 2386 if (lang) { 2387 for (; *lang; ++lang) { 2388 struct usb_string *str = (*lang)->strings; 2389 int id = first_id; 2390 for (; str->s; ++id, ++str) 2391 str->id = id; 2392 } 2393 } 2394 2395 ffs->gadget = cdev->gadget; 2396 ffs_data_get(ffs); 2397 return 0; 2398 } 2399 2400 static void functionfs_unbind(struct ffs_data *ffs) 2401 { 2402 if (!WARN_ON(!ffs->gadget)) { 2403 /* dequeue before freeing ep0req */ 2404 usb_ep_dequeue(ffs->gadget->ep0, ffs->ep0req); 2405 mutex_lock(&ffs->mutex); 2406 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req); 2407 ffs->ep0req = NULL; 2408 ffs->gadget = NULL; 2409 clear_bit(FFS_FL_BOUND, &ffs->flags); 2410 mutex_unlock(&ffs->mutex); 2411 ffs_data_put(ffs); 2412 } 2413 } 2414 2415 static int ffs_epfiles_create(struct ffs_data *ffs) 2416 { 2417 struct ffs_epfile *epfile, *epfiles; 2418 unsigned int i, count, epfiles_count; 2419 int err; 2420 2421 count = ffs->eps_count; 2422 epfiles_count = count; 2423 if (ffs->user_flags & FUNCTIONFS_RW_PROXY_EPS) 2424 epfiles_count += count / 2; 2425 ffs->epfiles_count = epfiles_count; 2426 2427 epfiles = kzalloc_objs(*epfiles, epfiles_count); 2428 if (!epfiles) 2429 return -ENOMEM; 2430 2431 epfile = epfiles; 2432 for (i = 1; i <= count; ++i, ++epfile) { 2433 epfile->ffs = ffs; 2434 mutex_init(&epfile->mutex); 2435 mutex_init(&epfile->dmabufs_mutex); 2436 INIT_LIST_HEAD(&epfile->dmabufs); 2437 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 2438 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]); 2439 else 2440 sprintf(epfile->name, "ep%u", i); 2441 epfile->in = (ffs->eps_addrmap[i] & USB_ENDPOINT_DIR_MASK) ? 1 : 0; 2442 err = ffs_sb_create_file(ffs->sb, epfile->name, 2443 epfile, &ffs_epfile_operations); 2444 if (err) { 2445 ffs_epfiles_destroy(ffs->sb, epfiles, i - 1); 2446 return err; 2447 } 2448 } 2449 2450 if (ffs->user_flags & FUNCTIONFS_RW_PROXY_EPS) { 2451 struct ffs_epfile *comp = epfiles + count; 2452 2453 for (i = 0; i < count; i += 2, ++comp) { 2454 struct ffs_epfile *ep1 = &epfiles[i]; 2455 struct ffs_epfile *ep2 = &epfiles[i + 1]; 2456 bool ep1_in = ffs->eps_addrmap[i + 1] & USB_ENDPOINT_DIR_MASK; 2457 2458 comp->ffs = ffs; 2459 comp->is_rw_proxy = true; 2460 comp->epfile_in = ep1_in ? ep1 : ep2; 2461 comp->epfile_out = ep1_in ? ep2 : ep1; 2462 mutex_init(&comp->mutex); 2463 mutex_init(&comp->dmabufs_mutex); 2464 INIT_LIST_HEAD(&comp->dmabufs); 2465 snprintf(comp->name, sizeof(comp->name), "%s_rw", 2466 epfiles[i].name); 2467 err = ffs_sb_create_file(ffs->sb, comp->name, 2468 comp, &ffs_epfile_operations); 2469 if (err) { 2470 ffs_epfiles_destroy(ffs->sb, epfiles, count + (i / 2)); 2471 return err; 2472 } 2473 } 2474 } 2475 2476 ffs->epfiles = epfiles; 2477 return 0; 2478 } 2479 2480 static void clear_one(struct dentry *dentry) 2481 { 2482 smp_store_release(&dentry->d_inode->i_private, NULL); 2483 } 2484 2485 static void ffs_epfiles_destroy(struct super_block *sb, 2486 struct ffs_epfile *epfiles, unsigned count) 2487 { 2488 struct ffs_epfile *epfile = epfiles; 2489 struct dentry *root = sb->s_root; 2490 2491 for (; count; --count, ++epfile) { 2492 BUG_ON(mutex_is_locked(&epfile->mutex)); 2493 __ffs_epfile_read_buffer_free(epfile); 2494 simple_remove_by_name(root, epfile->name, clear_one); 2495 } 2496 2497 kfree(epfiles); 2498 } 2499 2500 static void ffs_func_eps_disable(struct ffs_function *func) 2501 { 2502 struct ffs_ep *ep; 2503 struct ffs_epfile *epfile; 2504 unsigned short count; 2505 unsigned long flags; 2506 2507 spin_lock_irqsave(&func->ffs->eps_lock, flags); 2508 count = func->ffs->eps_count; 2509 epfile = func->ffs->epfiles; 2510 ep = func->eps; 2511 while (count--) { 2512 /* pending requests get nuked */ 2513 if (ep->ep) 2514 usb_ep_disable(ep->ep); 2515 ++ep; 2516 2517 if (epfile) { 2518 epfile->ep = NULL; 2519 __ffs_epfile_read_buffer_free(epfile); 2520 ++epfile; 2521 } 2522 } 2523 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 2524 } 2525 2526 static int ffs_func_eps_enable(struct ffs_function *func) 2527 { 2528 struct ffs_data *ffs; 2529 struct ffs_ep *ep; 2530 struct ffs_epfile *epfile; 2531 unsigned short count; 2532 unsigned long flags; 2533 int ret = 0; 2534 2535 spin_lock_irqsave(&func->ffs->eps_lock, flags); 2536 ffs = func->ffs; 2537 ep = func->eps; 2538 epfile = ffs->epfiles; 2539 count = ffs->eps_count; 2540 if (!epfile) { 2541 ret = -ENOMEM; 2542 goto done; 2543 } 2544 2545 while (count--) { 2546 ep->ep->driver_data = ep; 2547 2548 ret = config_ep_by_speed(func->gadget, &func->function, ep->ep); 2549 if (ret) { 2550 pr_err("%s: config_ep_by_speed(%s) returned %d\n", 2551 __func__, ep->ep->name, ret); 2552 break; 2553 } 2554 2555 ret = usb_ep_enable(ep->ep); 2556 if (!ret) { 2557 epfile->ep = ep; 2558 epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc); 2559 } else { 2560 break; 2561 } 2562 2563 ++ep; 2564 ++epfile; 2565 } 2566 2567 wake_up_interruptible(&ffs->wait); 2568 done: 2569 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 2570 2571 return ret; 2572 } 2573 2574 2575 /* Parsing and building descriptors and strings *****************************/ 2576 2577 /* 2578 * This validates if data pointed by data is a valid USB descriptor as 2579 * well as record how many interfaces, endpoints and strings are 2580 * required by given configuration. Returns address after the 2581 * descriptor or NULL if data is invalid. 2582 */ 2583 2584 enum ffs_entity_type { 2585 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT 2586 }; 2587 2588 enum ffs_os_desc_type { 2589 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP 2590 }; 2591 2592 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity, 2593 u8 *valuep, 2594 struct usb_descriptor_header *desc, 2595 void *priv); 2596 2597 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity, 2598 struct usb_os_desc_header *h, void *data, 2599 unsigned len, void *priv); 2600 2601 static int __must_check ffs_do_single_desc(char *data, unsigned len, 2602 ffs_entity_callback entity, 2603 void *priv, int *current_class, int *current_subclass) 2604 { 2605 struct usb_descriptor_header *_ds = (void *)data; 2606 u8 length; 2607 int ret; 2608 2609 /* At least two bytes are required: length and type */ 2610 if (len < 2) { 2611 pr_vdebug("descriptor too short\n"); 2612 return -EINVAL; 2613 } 2614 2615 /* If we have at least as many bytes as the descriptor takes? */ 2616 length = _ds->bLength; 2617 if (len < length) { 2618 pr_vdebug("descriptor longer then available data\n"); 2619 return -EINVAL; 2620 } 2621 2622 #define __entity_check_INTERFACE(val) 1 2623 #define __entity_check_STRING(val) (val) 2624 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK) 2625 #define __entity(type, val) do { \ 2626 pr_vdebug("entity " #type "(%02x)\n", (val)); \ 2627 if (!__entity_check_ ##type(val)) { \ 2628 pr_vdebug("invalid entity's value\n"); \ 2629 return -EINVAL; \ 2630 } \ 2631 ret = entity(FFS_ ##type, &val, _ds, priv); \ 2632 if (ret < 0) { \ 2633 pr_debug("entity " #type "(%02x); ret = %d\n", \ 2634 (val), ret); \ 2635 return ret; \ 2636 } \ 2637 } while (0) 2638 2639 /* Parse descriptor depending on type. */ 2640 switch (_ds->bDescriptorType) { 2641 case USB_DT_DEVICE: 2642 case USB_DT_CONFIG: 2643 case USB_DT_STRING: 2644 case USB_DT_DEVICE_QUALIFIER: 2645 /* function can't have any of those */ 2646 pr_vdebug("descriptor reserved for gadget: %d\n", 2647 _ds->bDescriptorType); 2648 return -EINVAL; 2649 2650 case USB_DT_INTERFACE: { 2651 struct usb_interface_descriptor *ds = (void *)_ds; 2652 pr_vdebug("interface descriptor\n"); 2653 if (length != sizeof *ds) 2654 goto inv_length; 2655 2656 __entity(INTERFACE, ds->bInterfaceNumber); 2657 if (ds->iInterface) 2658 __entity(STRING, ds->iInterface); 2659 *current_class = ds->bInterfaceClass; 2660 *current_subclass = ds->bInterfaceSubClass; 2661 } 2662 break; 2663 2664 case USB_DT_ENDPOINT: { 2665 struct usb_endpoint_descriptor *ds = (void *)_ds; 2666 pr_vdebug("endpoint descriptor\n"); 2667 if (length != USB_DT_ENDPOINT_SIZE && 2668 length != USB_DT_ENDPOINT_AUDIO_SIZE) 2669 goto inv_length; 2670 __entity(ENDPOINT, ds->bEndpointAddress); 2671 } 2672 break; 2673 2674 case USB_TYPE_CLASS | 0x01: 2675 if (*current_class == USB_INTERFACE_CLASS_HID) { 2676 pr_vdebug("hid descriptor\n"); 2677 if (length != sizeof(struct hid_descriptor)) 2678 goto inv_length; 2679 break; 2680 } else if (*current_class == USB_INTERFACE_CLASS_CCID) { 2681 pr_vdebug("ccid descriptor\n"); 2682 if (length != sizeof(struct ccid_descriptor)) 2683 goto inv_length; 2684 break; 2685 } else if (*current_class == USB_CLASS_APP_SPEC && 2686 *current_subclass == USB_SUBCLASS_DFU) { 2687 pr_vdebug("dfu functional descriptor\n"); 2688 if (length != sizeof(struct usb_dfu_functional_descriptor)) 2689 goto inv_length; 2690 break; 2691 } else { 2692 pr_vdebug("unknown descriptor: %d for class %d\n", 2693 _ds->bDescriptorType, *current_class); 2694 return -EINVAL; 2695 } 2696 2697 case USB_DT_OTG: 2698 if (length != sizeof(struct usb_otg_descriptor)) 2699 goto inv_length; 2700 break; 2701 2702 case USB_DT_INTERFACE_ASSOCIATION: { 2703 struct usb_interface_assoc_descriptor *ds = (void *)_ds; 2704 pr_vdebug("interface association descriptor\n"); 2705 if (length != sizeof *ds) 2706 goto inv_length; 2707 if (ds->iFunction) 2708 __entity(STRING, ds->iFunction); 2709 } 2710 break; 2711 2712 case USB_DT_SS_ENDPOINT_COMP: 2713 pr_vdebug("EP SS companion descriptor\n"); 2714 if (length != sizeof(struct usb_ss_ep_comp_descriptor)) 2715 goto inv_length; 2716 break; 2717 2718 case USB_DT_OTHER_SPEED_CONFIG: 2719 case USB_DT_INTERFACE_POWER: 2720 case USB_DT_DEBUG: 2721 case USB_DT_SECURITY: 2722 case USB_DT_CS_RADIO_CONTROL: 2723 /* TODO */ 2724 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType); 2725 return -EINVAL; 2726 2727 default: 2728 /* We should never be here */ 2729 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType); 2730 return -EINVAL; 2731 2732 inv_length: 2733 pr_vdebug("invalid length: %d (descriptor %d)\n", 2734 _ds->bLength, _ds->bDescriptorType); 2735 return -EINVAL; 2736 } 2737 2738 #undef __entity 2739 #undef __entity_check_DESCRIPTOR 2740 #undef __entity_check_INTERFACE 2741 #undef __entity_check_STRING 2742 #undef __entity_check_ENDPOINT 2743 2744 return length; 2745 } 2746 2747 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, 2748 ffs_entity_callback entity, void *priv) 2749 { 2750 const unsigned _len = len; 2751 unsigned long num = 0; 2752 int current_class = -1; 2753 int current_subclass = -1; 2754 2755 for (;;) { 2756 int ret; 2757 2758 if (num == count) 2759 data = NULL; 2760 2761 /* Record "descriptor" entity */ 2762 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv); 2763 if (ret < 0) { 2764 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n", 2765 num, ret); 2766 return ret; 2767 } 2768 2769 if (!data) 2770 return _len - len; 2771 2772 ret = ffs_do_single_desc(data, len, entity, priv, 2773 ¤t_class, ¤t_subclass); 2774 if (ret < 0) { 2775 pr_debug("%s returns %d\n", __func__, ret); 2776 return ret; 2777 } 2778 2779 len -= ret; 2780 data += ret; 2781 ++num; 2782 } 2783 } 2784 2785 static int __ffs_data_do_entity(enum ffs_entity_type type, 2786 u8 *valuep, struct usb_descriptor_header *desc, 2787 void *priv) 2788 { 2789 struct ffs_desc_helper *helper = priv; 2790 struct usb_endpoint_descriptor *d; 2791 2792 switch (type) { 2793 case FFS_DESCRIPTOR: 2794 break; 2795 2796 case FFS_INTERFACE: 2797 /* 2798 * Interfaces are indexed from zero so if we 2799 * encountered interface "n" then there are at least 2800 * "n+1" interfaces. 2801 */ 2802 if (*valuep >= helper->interfaces_count) 2803 helper->interfaces_count = *valuep + 1; 2804 break; 2805 2806 case FFS_STRING: 2807 /* 2808 * Strings are indexed from 1 (0 is reserved 2809 * for languages list) 2810 */ 2811 if (*valuep > helper->ffs->strings_count) 2812 helper->ffs->strings_count = *valuep; 2813 break; 2814 2815 case FFS_ENDPOINT: 2816 d = (void *)desc; 2817 helper->eps_count++; 2818 if (helper->eps_count >= FFS_MAX_EPS_COUNT) 2819 return -EINVAL; 2820 /* Check if descriptors for any speed were already parsed */ 2821 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count) 2822 helper->ffs->eps_addrmap[helper->eps_count] = 2823 d->bEndpointAddress; 2824 else if (helper->ffs->eps_addrmap[helper->eps_count] != 2825 d->bEndpointAddress) 2826 return -EINVAL; 2827 break; 2828 } 2829 2830 return 0; 2831 } 2832 2833 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type, 2834 struct usb_os_desc_header *desc) 2835 { 2836 u16 bcd_version = le16_to_cpu(desc->bcdVersion); 2837 u16 w_index = le16_to_cpu(desc->wIndex); 2838 2839 if (bcd_version == 0x1) { 2840 pr_warn("bcdVersion must be 0x0100, stored in Little Endian order. " 2841 "Userspace driver should be fixed, accepting 0x0001 for compatibility.\n"); 2842 } else if (bcd_version != 0x100) { 2843 pr_vdebug("unsupported os descriptors version: 0x%x\n", 2844 bcd_version); 2845 return -EINVAL; 2846 } 2847 switch (w_index) { 2848 case 0x4: 2849 *next_type = FFS_OS_DESC_EXT_COMPAT; 2850 break; 2851 case 0x5: 2852 *next_type = FFS_OS_DESC_EXT_PROP; 2853 break; 2854 default: 2855 pr_vdebug("unsupported os descriptor type: %d", w_index); 2856 return -EINVAL; 2857 } 2858 2859 return sizeof(*desc); 2860 } 2861 2862 /* 2863 * Process all extended compatibility/extended property descriptors 2864 * of a feature descriptor 2865 */ 2866 static int __must_check ffs_do_single_os_desc(char *data, unsigned len, 2867 enum ffs_os_desc_type type, 2868 u16 feature_count, 2869 ffs_os_desc_callback entity, 2870 void *priv, 2871 struct usb_os_desc_header *h) 2872 { 2873 int ret; 2874 const unsigned _len = len; 2875 2876 /* loop over all ext compat/ext prop descriptors */ 2877 while (feature_count--) { 2878 ret = entity(type, h, data, len, priv); 2879 if (ret < 0) { 2880 pr_debug("bad OS descriptor, type: %d\n", type); 2881 return ret; 2882 } 2883 data += ret; 2884 len -= ret; 2885 } 2886 return _len - len; 2887 } 2888 2889 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */ 2890 static int __must_check ffs_do_os_descs(unsigned count, 2891 char *data, unsigned len, 2892 ffs_os_desc_callback entity, void *priv) 2893 { 2894 const unsigned _len = len; 2895 unsigned long num = 0; 2896 2897 for (num = 0; num < count; ++num) { 2898 int ret; 2899 enum ffs_os_desc_type type; 2900 u16 feature_count; 2901 struct usb_os_desc_header *desc = (void *)data; 2902 2903 if (len < sizeof(*desc)) 2904 return -EINVAL; 2905 2906 /* 2907 * Record "descriptor" entity. 2908 * Process dwLength, bcdVersion, wIndex, get b/wCount. 2909 * Move the data pointer to the beginning of extended 2910 * compatibilities proper or extended properties proper 2911 * portions of the data 2912 */ 2913 if (le32_to_cpu(desc->dwLength) > len) 2914 return -EINVAL; 2915 2916 ret = __ffs_do_os_desc_header(&type, desc); 2917 if (ret < 0) { 2918 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n", 2919 num, ret); 2920 return ret; 2921 } 2922 /* 2923 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??" 2924 */ 2925 feature_count = le16_to_cpu(desc->wCount); 2926 if (type == FFS_OS_DESC_EXT_COMPAT && 2927 (feature_count > 255 || desc->Reserved)) 2928 return -EINVAL; 2929 len -= ret; 2930 data += ret; 2931 2932 /* 2933 * Process all function/property descriptors 2934 * of this Feature Descriptor 2935 */ 2936 ret = ffs_do_single_os_desc(data, len, type, 2937 feature_count, entity, priv, desc); 2938 if (ret < 0) { 2939 pr_debug("%s returns %d\n", __func__, ret); 2940 return ret; 2941 } 2942 2943 len -= ret; 2944 data += ret; 2945 } 2946 return _len - len; 2947 } 2948 2949 /* 2950 * Validate contents of the buffer from userspace related to OS descriptors. 2951 */ 2952 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type, 2953 struct usb_os_desc_header *h, void *data, 2954 unsigned len, void *priv) 2955 { 2956 struct ffs_data *ffs = priv; 2957 u8 length; 2958 2959 switch (type) { 2960 case FFS_OS_DESC_EXT_COMPAT: { 2961 struct usb_ext_compat_desc *d = data; 2962 int i; 2963 2964 if (len < sizeof(*d) || 2965 d->bFirstInterfaceNumber >= ffs->interfaces_count) 2966 return -EINVAL; 2967 if (d->Reserved1 != 1) { 2968 /* 2969 * According to the spec, Reserved1 must be set to 1 2970 * but older kernels incorrectly rejected non-zero 2971 * values. We fix it here to avoid returning EINVAL 2972 * in response to values we used to accept. 2973 */ 2974 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n"); 2975 d->Reserved1 = 1; 2976 } 2977 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i) 2978 if (d->Reserved2[i]) 2979 return -EINVAL; 2980 2981 length = sizeof(struct usb_ext_compat_desc); 2982 } 2983 break; 2984 case FFS_OS_DESC_EXT_PROP: { 2985 struct usb_ext_prop_desc *d = data; 2986 u32 type, pdl; 2987 u16 pnl; 2988 2989 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count) 2990 return -EINVAL; 2991 length = le32_to_cpu(d->dwSize); 2992 if (len < length) 2993 return -EINVAL; 2994 type = le32_to_cpu(d->dwPropertyDataType); 2995 if (type < USB_EXT_PROP_UNICODE || 2996 type > USB_EXT_PROP_UNICODE_MULTI) { 2997 pr_vdebug("unsupported os descriptor property type: %d", 2998 type); 2999 return -EINVAL; 3000 } 3001 pnl = le16_to_cpu(d->wPropertyNameLength); 3002 if (length < 14 + pnl) { 3003 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n", 3004 length, pnl, type); 3005 return -EINVAL; 3006 } 3007 pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl)); 3008 if (length != 14 + pnl + pdl) { 3009 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n", 3010 length, pnl, pdl, type); 3011 return -EINVAL; 3012 } 3013 ++ffs->ms_os_descs_ext_prop_count; 3014 /* property name reported to the host as "WCHAR"s */ 3015 ffs->ms_os_descs_ext_prop_name_len += pnl * 2; 3016 ffs->ms_os_descs_ext_prop_data_len += pdl; 3017 } 3018 break; 3019 default: 3020 pr_vdebug("unknown descriptor: %d\n", type); 3021 return -EINVAL; 3022 } 3023 return length; 3024 } 3025 3026 static int __ffs_data_got_descs(struct ffs_data *ffs, 3027 char *const _data, size_t len) 3028 { 3029 char *data = _data, *raw_descs; 3030 unsigned os_descs_count = 0, counts[3], flags; 3031 int ret = -EINVAL, i; 3032 struct ffs_desc_helper helper; 3033 3034 if (get_unaligned_le32(data + 4) != len) 3035 goto error; 3036 3037 switch (get_unaligned_le32(data)) { 3038 case FUNCTIONFS_DESCRIPTORS_MAGIC: 3039 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC; 3040 data += 8; 3041 len -= 8; 3042 break; 3043 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2: 3044 flags = get_unaligned_le32(data + 8); 3045 ffs->user_flags = flags; 3046 if (flags & ~(FUNCTIONFS_HAS_FS_DESC | 3047 FUNCTIONFS_HAS_HS_DESC | 3048 FUNCTIONFS_HAS_SS_DESC | 3049 FUNCTIONFS_HAS_MS_OS_DESC | 3050 FUNCTIONFS_VIRTUAL_ADDR | 3051 FUNCTIONFS_EVENTFD | 3052 FUNCTIONFS_ALL_CTRL_RECIP | 3053 FUNCTIONFS_CONFIG0_SETUP | 3054 FUNCTIONFS_RW_PROXY_EPS)) { 3055 ret = -ENOSYS; 3056 goto error; 3057 } 3058 data += 12; 3059 len -= 12; 3060 break; 3061 default: 3062 goto error; 3063 } 3064 3065 if (flags & FUNCTIONFS_EVENTFD) { 3066 if (len < 4) 3067 goto error; 3068 ffs->ffs_eventfd = 3069 eventfd_ctx_fdget((int)get_unaligned_le32(data)); 3070 if (IS_ERR(ffs->ffs_eventfd)) { 3071 ret = PTR_ERR(ffs->ffs_eventfd); 3072 ffs->ffs_eventfd = NULL; 3073 goto error; 3074 } 3075 data += 4; 3076 len -= 4; 3077 } 3078 3079 /* Read fs_count, hs_count and ss_count (if present) */ 3080 for (i = 0; i < 3; ++i) { 3081 if (!(flags & (1 << i))) { 3082 counts[i] = 0; 3083 } else if (len < 4) { 3084 goto error; 3085 } else { 3086 counts[i] = get_unaligned_le32(data); 3087 data += 4; 3088 len -= 4; 3089 } 3090 } 3091 if (flags & (1 << i)) { 3092 if (len < 4) { 3093 goto error; 3094 } 3095 os_descs_count = get_unaligned_le32(data); 3096 data += 4; 3097 len -= 4; 3098 } 3099 3100 /* Read descriptors */ 3101 raw_descs = data; 3102 helper.ffs = ffs; 3103 for (i = 0; i < 3; ++i) { 3104 if (!counts[i]) 3105 continue; 3106 helper.interfaces_count = 0; 3107 helper.eps_count = 0; 3108 ret = ffs_do_descs(counts[i], data, len, 3109 __ffs_data_do_entity, &helper); 3110 if (ret < 0) 3111 goto error; 3112 if (!ffs->eps_count && !ffs->interfaces_count) { 3113 ffs->eps_count = helper.eps_count; 3114 ffs->interfaces_count = helper.interfaces_count; 3115 } else { 3116 if (ffs->eps_count != helper.eps_count) { 3117 ret = -EINVAL; 3118 goto error; 3119 } 3120 if (ffs->interfaces_count != helper.interfaces_count) { 3121 ret = -EINVAL; 3122 goto error; 3123 } 3124 } 3125 data += ret; 3126 len -= ret; 3127 } 3128 if (os_descs_count) { 3129 ret = ffs_do_os_descs(os_descs_count, data, len, 3130 __ffs_data_do_os_desc, ffs); 3131 if (ret < 0) 3132 goto error; 3133 data += ret; 3134 len -= ret; 3135 } 3136 3137 if (raw_descs == data || len) { 3138 ret = -EINVAL; 3139 goto error; 3140 } 3141 3142 if (ffs->user_flags & FUNCTIONFS_RW_PROXY_EPS) { 3143 if (ffs->eps_count % 2) { 3144 ret = -EINVAL; 3145 goto error; 3146 } 3147 3148 for (i = 1; i < ffs->eps_count; i += 2) { 3149 if ((ffs->eps_addrmap[i] & USB_ENDPOINT_DIR_MASK) == 3150 (ffs->eps_addrmap[i + 1] & USB_ENDPOINT_DIR_MASK)) { 3151 ret = -EINVAL; 3152 goto error; 3153 } 3154 } 3155 } 3156 3157 ffs->raw_descs_data = _data; 3158 ffs->raw_descs = raw_descs; 3159 ffs->raw_descs_length = data - raw_descs; 3160 ffs->fs_descs_count = counts[0]; 3161 ffs->hs_descs_count = counts[1]; 3162 ffs->ss_descs_count = counts[2]; 3163 ffs->ms_os_descs_count = os_descs_count; 3164 3165 return 0; 3166 3167 error: 3168 kfree(_data); 3169 return ret; 3170 } 3171 3172 static int __ffs_data_got_strings(struct ffs_data *ffs, 3173 char *const _data, size_t len) 3174 { 3175 u32 str_count, needed_count, lang_count; 3176 struct usb_gadget_strings **stringtabs, *t; 3177 const char *data = _data; 3178 struct usb_string *s; 3179 3180 if (len < 16 || 3181 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC || 3182 get_unaligned_le32(data + 4) != len) 3183 goto error; 3184 str_count = get_unaligned_le32(data + 8); 3185 lang_count = get_unaligned_le32(data + 12); 3186 3187 /* if one is zero the other must be zero */ 3188 if (!str_count != !lang_count) 3189 goto error; 3190 3191 /* Do we have at least as many strings as descriptors need? */ 3192 needed_count = ffs->strings_count; 3193 if (str_count < needed_count) 3194 goto error; 3195 3196 /* 3197 * If we don't need any strings just return and free all 3198 * memory. 3199 */ 3200 if (!needed_count) { 3201 kfree(_data); 3202 return 0; 3203 } 3204 3205 /* Allocate everything in one chunk so there's less maintenance. */ 3206 { 3207 unsigned i = 0; 3208 vla_group(d); 3209 vla_item(d, struct usb_gadget_strings *, stringtabs, 3210 size_add(lang_count, 1)); 3211 vla_item(d, struct usb_gadget_strings, stringtab, lang_count); 3212 vla_item(d, struct usb_string, strings, 3213 size_mul(lang_count, (needed_count + 1))); 3214 3215 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL); 3216 3217 if (!vlabuf) { 3218 kfree(_data); 3219 return -ENOMEM; 3220 } 3221 3222 /* Initialize the VLA pointers */ 3223 stringtabs = vla_ptr(vlabuf, d, stringtabs); 3224 t = vla_ptr(vlabuf, d, stringtab); 3225 i = lang_count; 3226 do { 3227 *stringtabs++ = t++; 3228 } while (--i); 3229 *stringtabs = NULL; 3230 3231 /* stringtabs = vlabuf = d_stringtabs for later kfree */ 3232 stringtabs = vla_ptr(vlabuf, d, stringtabs); 3233 t = vla_ptr(vlabuf, d, stringtab); 3234 s = vla_ptr(vlabuf, d, strings); 3235 } 3236 3237 /* For each language */ 3238 data += 16; 3239 len -= 16; 3240 3241 do { /* lang_count > 0 so we can use do-while */ 3242 unsigned needed = needed_count; 3243 u32 str_per_lang = str_count; 3244 3245 if (len < 3) 3246 goto error_free; 3247 t->language = get_unaligned_le16(data); 3248 t->strings = s; 3249 ++t; 3250 3251 data += 2; 3252 len -= 2; 3253 3254 /* For each string */ 3255 do { /* str_count > 0 so we can use do-while */ 3256 size_t length = strnlen(data, len); 3257 3258 if (length == len) 3259 goto error_free; 3260 3261 /* 3262 * User may provide more strings then we need, 3263 * if that's the case we simply ignore the 3264 * rest 3265 */ 3266 if (needed) { 3267 /* 3268 * s->id will be set while adding 3269 * function to configuration so for 3270 * now just leave garbage here. 3271 */ 3272 s->s = data; 3273 --needed; 3274 ++s; 3275 } 3276 3277 data += length + 1; 3278 len -= length + 1; 3279 } while (--str_per_lang); 3280 3281 s->id = 0; /* terminator */ 3282 s->s = NULL; 3283 ++s; 3284 3285 } while (--lang_count); 3286 3287 /* Some garbage left? */ 3288 if (len) 3289 goto error_free; 3290 3291 /* Done! */ 3292 ffs->stringtabs = stringtabs; 3293 ffs->raw_strings = _data; 3294 3295 return 0; 3296 3297 error_free: 3298 kfree(stringtabs); 3299 error: 3300 kfree(_data); 3301 return -EINVAL; 3302 } 3303 3304 3305 /* Events handling and management *******************************************/ 3306 3307 static void __ffs_event_add(struct ffs_data *ffs, 3308 enum usb_functionfs_event_type type) 3309 { 3310 enum usb_functionfs_event_type rem_type1, rem_type2 = type; 3311 int neg = 0; 3312 3313 /* 3314 * Abort any unhandled setup 3315 * 3316 * We do not need to worry about some cmpxchg() changing value 3317 * of ffs->setup_state without holding the lock because when 3318 * state is FFS_SETUP_PENDING cmpxchg() in several places in 3319 * the source does nothing. 3320 */ 3321 if (ffs->setup_state == FFS_SETUP_PENDING) 3322 ffs->setup_state = FFS_SETUP_CANCELLED; 3323 3324 /* 3325 * Logic of this function guarantees that there are at most four pending 3326 * evens on ffs->ev.types queue. This is important because the queue 3327 * has space for four elements only and __ffs_ep0_read_events function 3328 * depends on that limit as well. If more event types are added, those 3329 * limits have to be revisited or guaranteed to still hold. 3330 */ 3331 switch (type) { 3332 case FUNCTIONFS_RESUME: 3333 rem_type2 = FUNCTIONFS_SUSPEND; 3334 fallthrough; 3335 case FUNCTIONFS_SUSPEND: 3336 case FUNCTIONFS_SETUP: 3337 rem_type1 = type; 3338 /* Discard all similar events */ 3339 break; 3340 3341 case FUNCTIONFS_BIND: 3342 case FUNCTIONFS_UNBIND: 3343 case FUNCTIONFS_DISABLE: 3344 case FUNCTIONFS_ENABLE: 3345 /* Discard everything other then power management. */ 3346 rem_type1 = FUNCTIONFS_SUSPEND; 3347 rem_type2 = FUNCTIONFS_RESUME; 3348 neg = 1; 3349 break; 3350 3351 default: 3352 WARN(1, "%d: unknown event, this should not happen\n", type); 3353 return; 3354 } 3355 3356 { 3357 u8 *ev = ffs->ev.types, *out = ev; 3358 unsigned n = ffs->ev.count; 3359 for (; n; --n, ++ev) 3360 if ((*ev == rem_type1 || *ev == rem_type2) == neg) 3361 *out++ = *ev; 3362 else 3363 pr_vdebug("purging event %d\n", *ev); 3364 ffs->ev.count = out - ffs->ev.types; 3365 } 3366 3367 pr_vdebug("adding event %d\n", type); 3368 ffs->ev.types[ffs->ev.count++] = type; 3369 wake_up_locked(&ffs->ev.waitq); 3370 if (ffs->ffs_eventfd) 3371 eventfd_signal(ffs->ffs_eventfd); 3372 } 3373 3374 static void ffs_event_add(struct ffs_data *ffs, 3375 enum usb_functionfs_event_type type) 3376 { 3377 unsigned long flags; 3378 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 3379 __ffs_event_add(ffs, type); 3380 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 3381 } 3382 3383 /* Bind/unbind USB function hooks *******************************************/ 3384 3385 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address) 3386 { 3387 int i; 3388 3389 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i) 3390 if (ffs->eps_addrmap[i] == endpoint_address) 3391 return i; 3392 return -ENOENT; 3393 } 3394 3395 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep, 3396 struct usb_descriptor_header *desc, 3397 void *priv) 3398 { 3399 struct usb_endpoint_descriptor *ds = (void *)desc; 3400 struct ffs_function *func = priv; 3401 struct ffs_ep *ffs_ep; 3402 unsigned ep_desc_id; 3403 int idx; 3404 static const char *speed_names[] = { "full", "high", "super" }; 3405 3406 if (type != FFS_DESCRIPTOR) 3407 return 0; 3408 3409 /* 3410 * If ss_descriptors is not NULL, we are reading super speed 3411 * descriptors; if hs_descriptors is not NULL, we are reading high 3412 * speed descriptors; otherwise, we are reading full speed 3413 * descriptors. 3414 */ 3415 if (func->function.ss_descriptors) { 3416 ep_desc_id = 2; 3417 func->function.ss_descriptors[(long)valuep] = desc; 3418 } else if (func->function.hs_descriptors) { 3419 ep_desc_id = 1; 3420 func->function.hs_descriptors[(long)valuep] = desc; 3421 } else { 3422 ep_desc_id = 0; 3423 func->function.fs_descriptors[(long)valuep] = desc; 3424 } 3425 3426 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) 3427 return 0; 3428 3429 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1; 3430 if (idx < 0) 3431 return idx; 3432 3433 ffs_ep = func->eps + idx; 3434 3435 if (ffs_ep->descs[ep_desc_id]) { 3436 pr_err("two %sspeed descriptors for EP %d\n", 3437 speed_names[ep_desc_id], 3438 usb_endpoint_num(ds)); 3439 return -EINVAL; 3440 } 3441 ffs_ep->descs[ep_desc_id] = ds; 3442 3443 ffs_dump_mem(": Original ep desc", ds, ds->bLength); 3444 if (ffs_ep->ep) { 3445 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress; 3446 if (!ds->wMaxPacketSize) 3447 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize; 3448 } else { 3449 struct usb_request *req; 3450 struct usb_ep *ep; 3451 u8 bEndpointAddress; 3452 __le16 wMaxPacketSize; 3453 3454 /* 3455 * We back up bEndpointAddress because autoconfig overwrites 3456 * it with physical endpoint address. 3457 */ 3458 bEndpointAddress = ds->bEndpointAddress; 3459 /* 3460 * We back up wMaxPacketSize because autoconfig treats 3461 * endpoint descriptors as if they were full speed. 3462 */ 3463 wMaxPacketSize = ds->wMaxPacketSize; 3464 pr_vdebug("autoconfig\n"); 3465 ep = usb_ep_autoconfig(func->gadget, ds); 3466 if (!ep) 3467 return -ENOTSUPP; 3468 ep->driver_data = func->eps + idx; 3469 3470 req = usb_ep_alloc_request(ep, GFP_KERNEL); 3471 if (!req) 3472 return -ENOMEM; 3473 3474 ffs_ep->ep = ep; 3475 ffs_ep->req = req; 3476 func->eps_revmap[ds->bEndpointAddress & 3477 USB_ENDPOINT_NUMBER_MASK] = idx + 1; 3478 /* 3479 * If we use virtual address mapping, we restore 3480 * original bEndpointAddress value. 3481 */ 3482 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 3483 ds->bEndpointAddress = bEndpointAddress; 3484 /* 3485 * Restore wMaxPacketSize which was potentially 3486 * overwritten by autoconfig. 3487 */ 3488 ds->wMaxPacketSize = wMaxPacketSize; 3489 } 3490 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength); 3491 3492 return 0; 3493 } 3494 3495 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep, 3496 struct usb_descriptor_header *desc, 3497 void *priv) 3498 { 3499 struct ffs_function *func = priv; 3500 unsigned idx; 3501 u8 newValue; 3502 3503 switch (type) { 3504 default: 3505 case FFS_DESCRIPTOR: 3506 /* Handled in previous pass by __ffs_func_bind_do_descs() */ 3507 return 0; 3508 3509 case FFS_INTERFACE: 3510 idx = *valuep; 3511 if (func->interfaces_nums[idx] < 0) { 3512 int id = usb_interface_id(func->conf, &func->function); 3513 if (id < 0) 3514 return id; 3515 func->interfaces_nums[idx] = id; 3516 } 3517 newValue = func->interfaces_nums[idx]; 3518 break; 3519 3520 case FFS_STRING: 3521 /* String' IDs are allocated when fsf_data is bound to cdev */ 3522 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id; 3523 break; 3524 3525 case FFS_ENDPOINT: 3526 /* 3527 * USB_DT_ENDPOINT are handled in 3528 * __ffs_func_bind_do_descs(). 3529 */ 3530 if (desc->bDescriptorType == USB_DT_ENDPOINT) 3531 return 0; 3532 3533 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1; 3534 if (!func->eps[idx].ep) 3535 return -EINVAL; 3536 3537 { 3538 struct usb_endpoint_descriptor **descs; 3539 descs = func->eps[idx].descs; 3540 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress; 3541 } 3542 break; 3543 } 3544 3545 pr_vdebug("%02x -> %02x\n", *valuep, newValue); 3546 *valuep = newValue; 3547 return 0; 3548 } 3549 3550 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type, 3551 struct usb_os_desc_header *h, void *data, 3552 unsigned len, void *priv) 3553 { 3554 struct ffs_function *func = priv; 3555 u8 length = 0; 3556 3557 switch (type) { 3558 case FFS_OS_DESC_EXT_COMPAT: { 3559 struct usb_ext_compat_desc *desc = data; 3560 struct usb_os_desc_table *t; 3561 3562 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber]; 3563 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber]; 3564 memcpy(t->os_desc->ext_compat_id, &desc->IDs, 3565 sizeof_field(struct usb_ext_compat_desc, IDs)); 3566 length = sizeof(*desc); 3567 } 3568 break; 3569 case FFS_OS_DESC_EXT_PROP: { 3570 struct usb_ext_prop_desc *desc = data; 3571 struct usb_os_desc_table *t; 3572 struct usb_os_desc_ext_prop *ext_prop; 3573 char *ext_prop_name; 3574 char *ext_prop_data; 3575 3576 t = &func->function.os_desc_table[h->interface]; 3577 t->if_id = func->interfaces_nums[h->interface]; 3578 3579 ext_prop = func->ffs->ms_os_descs_ext_prop_avail; 3580 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop); 3581 3582 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType); 3583 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength); 3584 ext_prop->data_len = le32_to_cpu(*(__le32 *) 3585 usb_ext_prop_data_len_ptr(data, ext_prop->name_len)); 3586 length = ext_prop->name_len + ext_prop->data_len + 14; 3587 3588 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail; 3589 func->ffs->ms_os_descs_ext_prop_name_avail += 3590 ext_prop->name_len; 3591 3592 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail; 3593 func->ffs->ms_os_descs_ext_prop_data_avail += 3594 ext_prop->data_len; 3595 memcpy(ext_prop_data, 3596 usb_ext_prop_data_ptr(data, ext_prop->name_len), 3597 ext_prop->data_len); 3598 /* unicode data reported to the host as "WCHAR"s */ 3599 switch (ext_prop->type) { 3600 case USB_EXT_PROP_UNICODE: 3601 case USB_EXT_PROP_UNICODE_ENV: 3602 case USB_EXT_PROP_UNICODE_LINK: 3603 case USB_EXT_PROP_UNICODE_MULTI: 3604 ext_prop->data_len *= 2; 3605 break; 3606 } 3607 ext_prop->data = ext_prop_data; 3608 3609 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data), 3610 ext_prop->name_len); 3611 /* property name reported to the host as "WCHAR"s */ 3612 ext_prop->name_len *= 2; 3613 ext_prop->name = ext_prop_name; 3614 3615 t->os_desc->ext_prop_len += 3616 ext_prop->name_len + ext_prop->data_len + 14; 3617 ++t->os_desc->ext_prop_count; 3618 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop); 3619 } 3620 break; 3621 default: 3622 pr_vdebug("unknown descriptor: %d\n", type); 3623 } 3624 3625 return length; 3626 } 3627 3628 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, 3629 struct usb_configuration *c) 3630 { 3631 struct ffs_function *func = ffs_func_from_usb(f); 3632 struct f_fs_opts *ffs_opts = 3633 container_of(f->fi, struct f_fs_opts, func_inst); 3634 struct ffs_data *ffs_data; 3635 int ret; 3636 3637 /* 3638 * Legacy gadget triggers binding in functionfs_ready_callback, 3639 * which already uses locking; taking the same lock here would 3640 * cause a deadlock. 3641 * 3642 * Configfs-enabled gadgets however do need ffs_dev_lock. 3643 */ 3644 if (!ffs_opts->no_configfs) 3645 ffs_dev_lock(); 3646 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV; 3647 ffs_data = ffs_opts->dev->ffs_data; 3648 if (!ffs_opts->no_configfs) 3649 ffs_dev_unlock(); 3650 if (ret) 3651 return ERR_PTR(ret); 3652 3653 func->ffs = ffs_data; 3654 func->conf = c; 3655 func->gadget = c->cdev->gadget; 3656 3657 /* 3658 * in drivers/usb/gadget/configfs.c:configfs_composite_bind() 3659 * configurations are bound in sequence with list_for_each_entry, 3660 * in each configuration its functions are bound in sequence 3661 * with list_for_each_entry, so we assume no race condition 3662 * with regard to ffs_opts->bound access 3663 */ 3664 if (!ffs_opts->refcnt) { 3665 ret = functionfs_bind(func->ffs, c->cdev); 3666 if (ret) 3667 return ERR_PTR(ret); 3668 } 3669 ffs_opts->refcnt++; 3670 func->function.strings = func->ffs->stringtabs; 3671 3672 return ffs_opts; 3673 } 3674 3675 static int _ffs_func_bind(struct usb_configuration *c, 3676 struct usb_function *f) 3677 { 3678 struct ffs_function *func = ffs_func_from_usb(f); 3679 struct ffs_data *ffs = func->ffs; 3680 3681 const int full = !!func->ffs->fs_descs_count; 3682 const int high = !!func->ffs->hs_descs_count; 3683 const int super = !!func->ffs->ss_descs_count; 3684 3685 int fs_len, hs_len, ss_len, ret, i; 3686 struct ffs_ep *eps_ptr; 3687 3688 /* Make it a single chunk, less management later on */ 3689 vla_group(d); 3690 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count); 3691 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs, 3692 full ? ffs->fs_descs_count + 1 : 0); 3693 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs, 3694 high ? ffs->hs_descs_count + 1 : 0); 3695 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs, 3696 super ? ffs->ss_descs_count + 1 : 0); 3697 vla_item_with_sz(d, short, inums, ffs->interfaces_count); 3698 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table, 3699 c->cdev->use_os_string ? ffs->interfaces_count : 0); 3700 vla_item_with_sz(d, char[16], ext_compat, 3701 c->cdev->use_os_string ? ffs->interfaces_count : 0); 3702 vla_item_with_sz(d, struct usb_os_desc, os_desc, 3703 c->cdev->use_os_string ? ffs->interfaces_count : 0); 3704 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop, 3705 ffs->ms_os_descs_ext_prop_count); 3706 vla_item_with_sz(d, char, ext_prop_name, 3707 ffs->ms_os_descs_ext_prop_name_len); 3708 vla_item_with_sz(d, char, ext_prop_data, 3709 ffs->ms_os_descs_ext_prop_data_len); 3710 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length); 3711 char *vlabuf; 3712 3713 /* Has descriptors only for speeds gadget does not support */ 3714 if (!(full | high | super)) 3715 return -ENOTSUPP; 3716 3717 /* Allocate a single chunk, less management later on */ 3718 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL); 3719 if (!vlabuf) 3720 return -ENOMEM; 3721 3722 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop); 3723 ffs->ms_os_descs_ext_prop_name_avail = 3724 vla_ptr(vlabuf, d, ext_prop_name); 3725 ffs->ms_os_descs_ext_prop_data_avail = 3726 vla_ptr(vlabuf, d, ext_prop_data); 3727 3728 /* Copy descriptors */ 3729 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs, 3730 ffs->raw_descs_length); 3731 3732 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz); 3733 eps_ptr = vla_ptr(vlabuf, d, eps); 3734 for (i = 0; i < ffs->eps_count; i++) 3735 eps_ptr[i].num = -1; 3736 3737 /* Save pointers 3738 * d_eps == vlabuf, func->eps used to kfree vlabuf later 3739 */ 3740 func->eps = vla_ptr(vlabuf, d, eps); 3741 func->interfaces_nums = vla_ptr(vlabuf, d, inums); 3742 3743 /* 3744 * Go through all the endpoint descriptors and allocate 3745 * endpoints first, so that later we can rewrite the endpoint 3746 * numbers without worrying that it may be described later on. 3747 */ 3748 if (full) { 3749 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs); 3750 fs_len = ffs_do_descs(ffs->fs_descs_count, 3751 vla_ptr(vlabuf, d, raw_descs), 3752 d_raw_descs__sz, 3753 __ffs_func_bind_do_descs, func); 3754 if (fs_len < 0) { 3755 ret = fs_len; 3756 goto error; 3757 } 3758 } else { 3759 fs_len = 0; 3760 } 3761 3762 if (high) { 3763 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs); 3764 hs_len = ffs_do_descs(ffs->hs_descs_count, 3765 vla_ptr(vlabuf, d, raw_descs) + fs_len, 3766 d_raw_descs__sz - fs_len, 3767 __ffs_func_bind_do_descs, func); 3768 if (hs_len < 0) { 3769 ret = hs_len; 3770 goto error; 3771 } 3772 } else { 3773 hs_len = 0; 3774 } 3775 3776 if (super) { 3777 func->function.ss_descriptors = func->function.ssp_descriptors = 3778 vla_ptr(vlabuf, d, ss_descs); 3779 ss_len = ffs_do_descs(ffs->ss_descs_count, 3780 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len, 3781 d_raw_descs__sz - fs_len - hs_len, 3782 __ffs_func_bind_do_descs, func); 3783 if (ss_len < 0) { 3784 ret = ss_len; 3785 goto error; 3786 } 3787 } else { 3788 ss_len = 0; 3789 } 3790 3791 /* 3792 * Now handle interface numbers allocation and interface and 3793 * endpoint numbers rewriting. We can do that in one go 3794 * now. 3795 */ 3796 ret = ffs_do_descs(ffs->fs_descs_count + 3797 (high ? ffs->hs_descs_count : 0) + 3798 (super ? ffs->ss_descs_count : 0), 3799 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz, 3800 __ffs_func_bind_do_nums, func); 3801 if (ret < 0) 3802 goto error; 3803 3804 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table); 3805 if (c->cdev->use_os_string) { 3806 for (i = 0; i < ffs->interfaces_count; ++i) { 3807 struct usb_os_desc *desc; 3808 3809 desc = func->function.os_desc_table[i].os_desc = 3810 vla_ptr(vlabuf, d, os_desc) + 3811 i * sizeof(struct usb_os_desc); 3812 desc->ext_compat_id = 3813 vla_ptr(vlabuf, d, ext_compat) + i * 16; 3814 INIT_LIST_HEAD(&desc->ext_prop); 3815 } 3816 ret = ffs_do_os_descs(ffs->ms_os_descs_count, 3817 vla_ptr(vlabuf, d, raw_descs) + 3818 fs_len + hs_len + ss_len, 3819 d_raw_descs__sz - fs_len - hs_len - 3820 ss_len, 3821 __ffs_func_bind_do_os_desc, func); 3822 if (ret < 0) 3823 goto error; 3824 } 3825 func->function.os_desc_n = 3826 c->cdev->use_os_string ? ffs->interfaces_count : 0; 3827 3828 /* And we're done */ 3829 ffs_event_add(ffs, FUNCTIONFS_BIND); 3830 return 0; 3831 3832 error: 3833 /* XXX Do we need to release all claimed endpoints here? */ 3834 return ret; 3835 } 3836 3837 static int ffs_func_bind(struct usb_configuration *c, 3838 struct usb_function *f) 3839 { 3840 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c); 3841 struct ffs_function *func = ffs_func_from_usb(f); 3842 int ret; 3843 3844 if (IS_ERR(ffs_opts)) 3845 return PTR_ERR(ffs_opts); 3846 3847 ret = _ffs_func_bind(c, f); 3848 if (ret && !--ffs_opts->refcnt) 3849 functionfs_unbind(func->ffs); 3850 3851 return ret; 3852 } 3853 3854 3855 /* Other USB function hooks *************************************************/ 3856 3857 static void ffs_reset_work(struct work_struct *work) 3858 { 3859 struct ffs_data *ffs = container_of(work, 3860 struct ffs_data, reset_work); 3861 ffs_data_reset(ffs); 3862 } 3863 3864 static int ffs_func_get_alt(struct usb_function *f, 3865 unsigned int interface) 3866 { 3867 struct ffs_function *func = ffs_func_from_usb(f); 3868 int intf = ffs_func_revmap_intf(func, interface); 3869 3870 return (intf < 0) ? intf : func->cur_alt[interface]; 3871 } 3872 3873 static int ffs_func_set_alt(struct usb_function *f, 3874 unsigned interface, unsigned alt) 3875 { 3876 struct ffs_function *func = ffs_func_from_usb(f); 3877 struct ffs_data *ffs = func->ffs; 3878 unsigned long flags; 3879 int ret = 0, intf; 3880 3881 if (alt > MAX_ALT_SETTINGS) 3882 return -EINVAL; 3883 3884 intf = ffs_func_revmap_intf(func, interface); 3885 if (intf < 0) 3886 return intf; 3887 3888 if (ffs->func) 3889 ffs_func_eps_disable(ffs->func); 3890 3891 spin_lock_irqsave(&ffs->eps_lock, flags); 3892 if (ffs->state == FFS_DEACTIVATED) { 3893 ffs->state = FFS_CLOSING; 3894 spin_unlock_irqrestore(&ffs->eps_lock, flags); 3895 schedule_work(&ffs->reset_work); 3896 return -ENODEV; 3897 } 3898 spin_unlock_irqrestore(&ffs->eps_lock, flags); 3899 3900 if (ffs->state != FFS_ACTIVE) 3901 return -ENODEV; 3902 3903 ffs->func = func; 3904 ret = ffs_func_eps_enable(func); 3905 if (ret >= 0) { 3906 ffs_event_add(ffs, FUNCTIONFS_ENABLE); 3907 func->cur_alt[interface] = alt; 3908 } 3909 return ret; 3910 } 3911 3912 static void ffs_func_disable(struct usb_function *f) 3913 { 3914 struct ffs_function *func = ffs_func_from_usb(f); 3915 struct ffs_data *ffs = func->ffs; 3916 unsigned long flags; 3917 3918 if (ffs->func) 3919 ffs_func_eps_disable(ffs->func); 3920 3921 spin_lock_irqsave(&ffs->eps_lock, flags); 3922 if (ffs->state == FFS_DEACTIVATED) { 3923 ffs->state = FFS_CLOSING; 3924 spin_unlock_irqrestore(&ffs->eps_lock, flags); 3925 schedule_work(&ffs->reset_work); 3926 return; 3927 } 3928 spin_unlock_irqrestore(&ffs->eps_lock, flags); 3929 3930 if (ffs->state == FFS_ACTIVE) { 3931 ffs->func = NULL; 3932 ffs_event_add(ffs, FUNCTIONFS_DISABLE); 3933 } 3934 } 3935 3936 static int ffs_func_setup(struct usb_function *f, 3937 const struct usb_ctrlrequest *creq) 3938 { 3939 struct ffs_function *func = ffs_func_from_usb(f); 3940 struct ffs_data *ffs = func->ffs; 3941 unsigned long flags; 3942 int ret; 3943 3944 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType); 3945 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest); 3946 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue)); 3947 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex)); 3948 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength)); 3949 3950 /* 3951 * Most requests directed to interface go through here 3952 * (notable exceptions are set/get interface) so we need to 3953 * handle them. All other either handled by composite or 3954 * passed to usb_configuration->setup() (if one is set). No 3955 * matter, we will handle requests directed to endpoint here 3956 * as well (as it's straightforward). Other request recipient 3957 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP 3958 * is being used. 3959 */ 3960 if (ffs->state != FFS_ACTIVE) 3961 return -ENODEV; 3962 3963 switch (creq->bRequestType & USB_RECIP_MASK) { 3964 case USB_RECIP_INTERFACE: 3965 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex)); 3966 if (ret < 0) 3967 return ret; 3968 break; 3969 3970 case USB_RECIP_ENDPOINT: 3971 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex)); 3972 if (ret < 0) 3973 return ret; 3974 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 3975 ret = func->ffs->eps_addrmap[ret]; 3976 break; 3977 3978 default: 3979 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP) 3980 ret = le16_to_cpu(creq->wIndex); 3981 else 3982 return -EOPNOTSUPP; 3983 } 3984 3985 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 3986 ffs->ev.setup = *creq; 3987 ffs->ev.setup.wIndex = cpu_to_le16(ret); 3988 __ffs_event_add(ffs, FUNCTIONFS_SETUP); 3989 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 3990 3991 return ffs->ev.setup.wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0; 3992 } 3993 3994 static bool ffs_func_req_match(struct usb_function *f, 3995 const struct usb_ctrlrequest *creq, 3996 bool config0) 3997 { 3998 struct ffs_function *func = ffs_func_from_usb(f); 3999 4000 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP)) 4001 return false; 4002 4003 switch (creq->bRequestType & USB_RECIP_MASK) { 4004 case USB_RECIP_INTERFACE: 4005 return (ffs_func_revmap_intf(func, 4006 le16_to_cpu(creq->wIndex)) >= 0); 4007 case USB_RECIP_ENDPOINT: 4008 return (ffs_func_revmap_ep(func, 4009 le16_to_cpu(creq->wIndex)) >= 0); 4010 default: 4011 return (bool) (func->ffs->user_flags & 4012 FUNCTIONFS_ALL_CTRL_RECIP); 4013 } 4014 } 4015 4016 static void ffs_func_suspend(struct usb_function *f) 4017 { 4018 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND); 4019 } 4020 4021 static void ffs_func_resume(struct usb_function *f) 4022 { 4023 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME); 4024 } 4025 4026 4027 /* Endpoint and interface numbers reverse mapping ***************************/ 4028 4029 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) 4030 { 4031 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK]; 4032 return num ? num : -EDOM; 4033 } 4034 4035 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) 4036 { 4037 short *nums = func->interfaces_nums; 4038 unsigned count = func->ffs->interfaces_count; 4039 4040 for (; count; --count, ++nums) { 4041 if (*nums >= 0 && *nums == intf) 4042 return nums - func->interfaces_nums; 4043 } 4044 4045 return -EDOM; 4046 } 4047 4048 4049 /* Devices management *******************************************************/ 4050 4051 static LIST_HEAD(ffs_devices); 4052 4053 static struct ffs_dev *_ffs_do_find_dev(const char *name) 4054 { 4055 struct ffs_dev *dev; 4056 4057 if (!name) 4058 return NULL; 4059 4060 list_for_each_entry(dev, &ffs_devices, entry) { 4061 if (strcmp(dev->name, name) == 0) 4062 return dev; 4063 } 4064 4065 return NULL; 4066 } 4067 4068 /* 4069 * ffs_lock must be taken by the caller of this function 4070 */ 4071 static struct ffs_dev *_ffs_get_single_dev(void) 4072 { 4073 struct ffs_dev *dev; 4074 4075 if (list_is_singular(&ffs_devices)) { 4076 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry); 4077 if (dev->single) 4078 return dev; 4079 } 4080 4081 return NULL; 4082 } 4083 4084 /* 4085 * ffs_lock must be taken by the caller of this function 4086 */ 4087 static struct ffs_dev *_ffs_find_dev(const char *name) 4088 { 4089 struct ffs_dev *dev; 4090 4091 dev = _ffs_get_single_dev(); 4092 if (dev) 4093 return dev; 4094 4095 return _ffs_do_find_dev(name); 4096 } 4097 4098 /* Configfs support *********************************************************/ 4099 4100 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item) 4101 { 4102 return container_of(to_config_group(item), struct f_fs_opts, 4103 func_inst.group); 4104 } 4105 4106 static ssize_t f_fs_opts_ready_show(struct config_item *item, char *page) 4107 { 4108 struct f_fs_opts *opts = to_ffs_opts(item); 4109 int ready; 4110 4111 ffs_dev_lock(); 4112 ready = opts->dev->desc_ready; 4113 ffs_dev_unlock(); 4114 4115 return sprintf(page, "%d\n", ready); 4116 } 4117 4118 CONFIGFS_ATTR_RO(f_fs_opts_, ready); 4119 4120 static struct configfs_attribute *ffs_attrs[] = { 4121 &f_fs_opts_attr_ready, 4122 NULL, 4123 }; 4124 4125 static void ffs_attr_release(struct config_item *item) 4126 { 4127 struct f_fs_opts *opts = to_ffs_opts(item); 4128 4129 usb_put_function_instance(&opts->func_inst); 4130 } 4131 4132 static const struct configfs_item_operations ffs_item_ops = { 4133 .release = ffs_attr_release, 4134 }; 4135 4136 static const struct config_item_type ffs_func_type = { 4137 .ct_item_ops = &ffs_item_ops, 4138 .ct_attrs = ffs_attrs, 4139 .ct_owner = THIS_MODULE, 4140 }; 4141 4142 4143 /* Function registration interface ******************************************/ 4144 4145 static void ffs_free_inst(struct usb_function_instance *f) 4146 { 4147 struct f_fs_opts *opts; 4148 4149 opts = to_f_fs_opts(f); 4150 ffs_release_dev(opts->dev); 4151 ffs_dev_lock(); 4152 _ffs_free_dev(opts->dev); 4153 ffs_dev_unlock(); 4154 kfree(opts); 4155 } 4156 4157 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name) 4158 { 4159 if (strlen(name) >= sizeof_field(struct ffs_dev, name)) 4160 return -ENAMETOOLONG; 4161 return ffs_name_dev(to_f_fs_opts(fi)->dev, name); 4162 } 4163 4164 static struct usb_function_instance *ffs_alloc_inst(void) 4165 { 4166 struct f_fs_opts *opts; 4167 struct ffs_dev *dev; 4168 4169 opts = kzalloc_obj(*opts); 4170 if (!opts) 4171 return ERR_PTR(-ENOMEM); 4172 4173 opts->func_inst.set_inst_name = ffs_set_inst_name; 4174 opts->func_inst.free_func_inst = ffs_free_inst; 4175 ffs_dev_lock(); 4176 dev = _ffs_alloc_dev(); 4177 ffs_dev_unlock(); 4178 if (IS_ERR(dev)) { 4179 kfree(opts); 4180 return ERR_CAST(dev); 4181 } 4182 opts->dev = dev; 4183 dev->opts = opts; 4184 4185 config_group_init_type_name(&opts->func_inst.group, "", 4186 &ffs_func_type); 4187 return &opts->func_inst; 4188 } 4189 4190 static void ffs_free(struct usb_function *f) 4191 { 4192 kfree(ffs_func_from_usb(f)); 4193 } 4194 4195 static void ffs_func_unbind(struct usb_configuration *c, 4196 struct usb_function *f) 4197 { 4198 struct ffs_function *func = ffs_func_from_usb(f); 4199 struct ffs_data *ffs = func->ffs; 4200 struct f_fs_opts *opts = 4201 container_of(f->fi, struct f_fs_opts, func_inst); 4202 struct ffs_ep *ep = func->eps; 4203 unsigned count = ffs->eps_count; 4204 unsigned long flags; 4205 4206 if (ffs->func == func) { 4207 ffs_func_eps_disable(func); 4208 ffs->func = NULL; 4209 } 4210 4211 /* Drain any pending AIO completions */ 4212 drain_workqueue(ffs->io_completion_wq); 4213 4214 ffs_event_add(ffs, FUNCTIONFS_UNBIND); 4215 if (!--opts->refcnt) 4216 functionfs_unbind(ffs); 4217 4218 /* cleanup after autoconfig */ 4219 spin_lock_irqsave(&func->ffs->eps_lock, flags); 4220 while (count--) { 4221 if (ep->ep && ep->req) 4222 usb_ep_free_request(ep->ep, ep->req); 4223 ep->req = NULL; 4224 ++ep; 4225 } 4226 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 4227 kfree(func->eps); 4228 func->eps = NULL; 4229 /* 4230 * eps, descriptors and interfaces_nums are allocated in the 4231 * same chunk so only one free is required. 4232 */ 4233 func->function.fs_descriptors = NULL; 4234 func->function.hs_descriptors = NULL; 4235 func->function.ss_descriptors = NULL; 4236 func->function.ssp_descriptors = NULL; 4237 func->interfaces_nums = NULL; 4238 4239 } 4240 4241 static struct usb_function *ffs_alloc(struct usb_function_instance *fi) 4242 { 4243 struct ffs_function *func; 4244 4245 func = kzalloc_obj(*func); 4246 if (!func) 4247 return ERR_PTR(-ENOMEM); 4248 4249 func->function.name = "Function FS Gadget"; 4250 4251 func->function.bind = ffs_func_bind; 4252 func->function.unbind = ffs_func_unbind; 4253 func->function.set_alt = ffs_func_set_alt; 4254 func->function.get_alt = ffs_func_get_alt; 4255 func->function.disable = ffs_func_disable; 4256 func->function.setup = ffs_func_setup; 4257 func->function.req_match = ffs_func_req_match; 4258 func->function.suspend = ffs_func_suspend; 4259 func->function.resume = ffs_func_resume; 4260 func->function.free_func = ffs_free; 4261 4262 return &func->function; 4263 } 4264 4265 /* 4266 * ffs_lock must be taken by the caller of this function 4267 */ 4268 static struct ffs_dev *_ffs_alloc_dev(void) 4269 { 4270 struct ffs_dev *dev; 4271 int ret; 4272 4273 if (_ffs_get_single_dev()) 4274 return ERR_PTR(-EBUSY); 4275 4276 dev = kzalloc_obj(*dev); 4277 if (!dev) 4278 return ERR_PTR(-ENOMEM); 4279 4280 if (list_empty(&ffs_devices)) { 4281 ret = functionfs_init(); 4282 if (ret) { 4283 kfree(dev); 4284 return ERR_PTR(ret); 4285 } 4286 } 4287 4288 list_add(&dev->entry, &ffs_devices); 4289 4290 return dev; 4291 } 4292 4293 int ffs_name_dev(struct ffs_dev *dev, const char *name) 4294 { 4295 struct ffs_dev *existing; 4296 int ret = 0; 4297 4298 ffs_dev_lock(); 4299 4300 existing = _ffs_do_find_dev(name); 4301 if (!existing) 4302 strscpy(dev->name, name, ARRAY_SIZE(dev->name)); 4303 else if (existing != dev) 4304 ret = -EBUSY; 4305 4306 ffs_dev_unlock(); 4307 4308 return ret; 4309 } 4310 EXPORT_SYMBOL_GPL(ffs_name_dev); 4311 4312 int ffs_single_dev(struct ffs_dev *dev) 4313 { 4314 int ret; 4315 4316 ret = 0; 4317 ffs_dev_lock(); 4318 4319 if (!list_is_singular(&ffs_devices)) 4320 ret = -EBUSY; 4321 else 4322 dev->single = true; 4323 4324 ffs_dev_unlock(); 4325 return ret; 4326 } 4327 EXPORT_SYMBOL_GPL(ffs_single_dev); 4328 4329 /* 4330 * ffs_lock must be taken by the caller of this function 4331 */ 4332 static void _ffs_free_dev(struct ffs_dev *dev) 4333 { 4334 list_del(&dev->entry); 4335 4336 kfree(dev); 4337 if (list_empty(&ffs_devices)) 4338 functionfs_cleanup(); 4339 } 4340 4341 static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data) 4342 { 4343 int ret = 0; 4344 struct ffs_dev *ffs_dev; 4345 4346 ffs_dev_lock(); 4347 4348 ffs_dev = _ffs_find_dev(dev_name); 4349 if (!ffs_dev) { 4350 ret = -ENOENT; 4351 } else if (ffs_dev->mounted) { 4352 ret = -EBUSY; 4353 } else if (ffs_dev->ffs_acquire_dev_callback && 4354 ffs_dev->ffs_acquire_dev_callback(ffs_dev)) { 4355 ret = -ENOENT; 4356 } else { 4357 ffs_dev->mounted = true; 4358 ffs_dev->ffs_data = ffs_data; 4359 ffs_data->private_data = ffs_dev; 4360 } 4361 4362 ffs_dev_unlock(); 4363 return ret; 4364 } 4365 4366 static void ffs_release_dev(struct ffs_dev *ffs_dev) 4367 { 4368 ffs_dev_lock(); 4369 4370 if (ffs_dev && ffs_dev->mounted) { 4371 ffs_dev->mounted = false; 4372 if (ffs_dev->ffs_data) { 4373 ffs_dev->ffs_data->private_data = NULL; 4374 ffs_dev->ffs_data = NULL; 4375 } 4376 4377 if (ffs_dev->ffs_release_dev_callback) 4378 ffs_dev->ffs_release_dev_callback(ffs_dev); 4379 } 4380 4381 ffs_dev_unlock(); 4382 } 4383 4384 static int ffs_ready(struct ffs_data *ffs) 4385 { 4386 struct ffs_dev *ffs_obj; 4387 int ret = 0; 4388 4389 ffs_dev_lock(); 4390 4391 ffs_obj = ffs->private_data; 4392 if (!ffs_obj) { 4393 ret = -EINVAL; 4394 goto done; 4395 } 4396 if (WARN_ON(ffs_obj->desc_ready)) { 4397 ret = -EBUSY; 4398 goto done; 4399 } 4400 4401 ffs_obj->desc_ready = true; 4402 4403 if (ffs_obj->ffs_ready_callback) { 4404 ret = ffs_obj->ffs_ready_callback(ffs); 4405 if (ret) 4406 goto done; 4407 } 4408 4409 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags); 4410 done: 4411 ffs_dev_unlock(); 4412 return ret; 4413 } 4414 4415 static void ffs_closed(struct ffs_data *ffs) 4416 { 4417 struct ffs_dev *ffs_obj; 4418 struct f_fs_opts *opts; 4419 struct config_item *ci; 4420 4421 ffs_dev_lock(); 4422 4423 ffs_obj = ffs->private_data; 4424 if (!ffs_obj) 4425 goto done; 4426 4427 ffs_obj->desc_ready = false; 4428 4429 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && 4430 ffs_obj->ffs_closed_callback) 4431 ffs_obj->ffs_closed_callback(ffs); 4432 4433 if (ffs_obj->opts) 4434 opts = ffs_obj->opts; 4435 else 4436 goto done; 4437 4438 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent 4439 || !kref_read(&opts->func_inst.group.cg_item.ci_kref)) 4440 goto done; 4441 4442 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent; 4443 ffs_dev_unlock(); 4444 4445 if (test_bit(FFS_FL_BOUND, &ffs->flags)) 4446 unregister_gadget_item(ci); 4447 return; 4448 done: 4449 ffs_dev_unlock(); 4450 } 4451 4452 /* Misc helper functions ****************************************************/ 4453 4454 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 4455 { 4456 return nonblock 4457 ? mutex_trylock(mutex) ? 0 : -EAGAIN 4458 : mutex_lock_interruptible(mutex); 4459 } 4460 4461 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 4462 { 4463 char *data; 4464 4465 if (!len) 4466 return NULL; 4467 4468 data = memdup_user(buf, len); 4469 if (IS_ERR(data)) 4470 return data; 4471 4472 pr_vdebug("Buffer from user space:\n"); 4473 ffs_dump_mem("", data, len); 4474 4475 return data; 4476 } 4477 4478 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc); 4479 MODULE_DESCRIPTION("user mode file system API for USB composite function controllers"); 4480 MODULE_LICENSE("GPL"); 4481 MODULE_AUTHOR("Michal Nazarewicz"); 4482