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