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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / drivers / usb / gadget / function / f_fs.c
blobc2592d883f67c45f980c21cfa4181f77fac14760
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/pagemap.h>
19 #include <linux/export.h>
20 #include <linux/hid.h>
21 #include <linux/module.h>
22 #include <linux/sched/signal.h>
23 #include <linux/uio.h>
24 #include <asm/unaligned.h>
25
26 #include <linux/usb/composite.h>
27 #include <linux/usb/functionfs.h>
28
29 #include <linux/aio.h>
30 #include <linux/mmu_context.h>
31 #include <linux/poll.h>
32 #include <linux/eventfd.h>
33
34 #include "u_fs.h"
35 #include "u_f.h"
36 #include "u_os_desc.h"
37 #include "configfs.h"
38
39 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
40
41 /* Reference counter handling */
42 static void ffs_data_get(struct ffs_data *ffs);
43 static void ffs_data_put(struct ffs_data *ffs);
44 /* Creates new ffs_data object. */
45 static struct ffs_data *__must_check ffs_data_new(const char *dev_name)
46 __attribute__((malloc));
47
48 /* Opened counter handling. */
49 static void ffs_data_opened(struct ffs_data *ffs);
50 static void ffs_data_closed(struct ffs_data *ffs);
51
52 /* Called with ffs->mutex held; take over ownership of data. */
53 static int __must_check
54 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
55 static int __must_check
56 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
57
58
59 /* The function structure ***************************************************/
60
61 struct ffs_ep;
62
63 struct ffs_function {
64 struct usb_configuration *conf;
65 struct usb_gadget *gadget;
66 struct ffs_data *ffs;
67
68 struct ffs_ep *eps;
69 u8 eps_revmap[16];
70 short *interfaces_nums;
71
72 struct usb_function function;
73 };
74
75
76 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
77 {
78 return container_of(f, struct ffs_function, function);
79 }
80
81
82 static inline enum ffs_setup_state
83 ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
84 {
85 return (enum ffs_setup_state)
86 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
87 }
88
89
90 static void ffs_func_eps_disable(struct ffs_function *func);
91 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
92
93 static int ffs_func_bind(struct usb_configuration *,
94 struct usb_function *);
95 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
96 static void ffs_func_disable(struct usb_function *);
97 static int ffs_func_setup(struct usb_function *,
98 const struct usb_ctrlrequest *);
99 static bool ffs_func_req_match(struct usb_function *,
100 const struct usb_ctrlrequest *,
101 bool config0);
102 static void ffs_func_suspend(struct usb_function *);
103 static void ffs_func_resume(struct usb_function *);
104
105
106 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
107 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
108
109
110 /* The endpoints structures *************************************************/
111
112 struct ffs_ep {
113 struct usb_ep *ep; /* P: ffs->eps_lock */
114 struct usb_request *req; /* P: epfile->mutex */
115
116 /* [0]: full speed, [1]: high speed, [2]: super speed */
117 struct usb_endpoint_descriptor *descs[3];
118
119 u8 num;
120
121 int status; /* P: epfile->mutex */
122 };
123
124 struct ffs_epfile {
125 /* Protects ep->ep and ep->req. */
126 struct mutex mutex;
127
128 struct ffs_data *ffs;
129 struct ffs_ep *ep; /* P: ffs->eps_lock */
130
131 struct dentry *dentry;
132
133 /*
134 * Buffer for holding data from partial reads which may happen since
135 * we’re rounding user read requests to a multiple of a max packet size.
136 *
137 * The pointer is initialised with NULL value and may be set by
138 * __ffs_epfile_read_data function to point to a temporary buffer.
139 *
140 * In normal operation, calls to __ffs_epfile_read_buffered will consume
141 * data from said buffer and eventually free it. Importantly, while the
142 * function is using the buffer, it sets the pointer to NULL. This is
143 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered
144 * can never run concurrently (they are synchronised by epfile->mutex)
145 * so the latter will not assign a new value to the pointer.
146 *
147 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is
148 * valid) and sets the pointer to READ_BUFFER_DROP value. This special
149 * value is crux of the synchronisation between ffs_func_eps_disable and
150 * __ffs_epfile_read_data.
151 *
152 * Once __ffs_epfile_read_data is about to finish it will try to set the
153 * pointer back to its old value (as described above), but seeing as the
154 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free
155 * the buffer.
156 *
157 * == State transitions ==
158 *
159 * • ptr == NULL: (initial state)
160 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP
161 * ◦ __ffs_epfile_read_buffered: nop
162 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf
163 * ◦ reading finishes: n/a, not in ‘and reading’ state
164 * • ptr == DROP:
165 * ◦ __ffs_epfile_read_buffer_free: nop
166 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL
167 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop
168 * ◦ reading finishes: n/a, not in ‘and reading’ state
169 * • ptr == buf:
170 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP
171 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading
172 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered
173 * is always called first
174 * ◦ reading finishes: n/a, not in ‘and reading’ state
175 * • ptr == NULL and reading:
176 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading
177 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
178 * ◦ __ffs_epfile_read_data: n/a, mutex is held
179 * ◦ reading finishes and …
180 * … all data read: free buf, go to ptr == NULL
181 * … otherwise: go to ptr == buf and reading
182 * • ptr == DROP and reading:
183 * ◦ __ffs_epfile_read_buffer_free: nop
184 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
185 * ◦ __ffs_epfile_read_data: n/a, mutex is held
186 * ◦ reading finishes: free buf, go to ptr == DROP
187 */
188 struct ffs_buffer *read_buffer;
189 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN))
190
191 char name[5];
192
193 unsigned char in; /* P: ffs->eps_lock */
194 unsigned char isoc; /* P: ffs->eps_lock */
195
196 unsigned char _pad;
197 };
198
199 struct ffs_buffer {
200 size_t length;
201 char *data;
202 char storage[];
203 };
204
205 /* ffs_io_data structure ***************************************************/
206
207 struct ffs_io_data {
208 bool aio;
209 bool read;
210
211 struct kiocb *kiocb;
212 struct iov_iter data;
213 const void *to_free;
214 char *buf;
215
216 struct mm_struct *mm;
217 struct work_struct work;
218
219 struct usb_ep *ep;
220 struct usb_request *req;
221
222 struct ffs_data *ffs;
223 };
224
225 struct ffs_desc_helper {
226 struct ffs_data *ffs;
227 unsigned interfaces_count;
228 unsigned eps_count;
229 };
230
231 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
232 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
233
234 static struct dentry *
235 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
236 const struct file_operations *fops);
237
238 /* Devices management *******************************************************/
239
240 DEFINE_MUTEX(ffs_lock);
241 EXPORT_SYMBOL_GPL(ffs_lock);
242
243 static struct ffs_dev *_ffs_find_dev(const char *name);
244 static struct ffs_dev *_ffs_alloc_dev(void);
245 static void _ffs_free_dev(struct ffs_dev *dev);
246 static void *ffs_acquire_dev(const char *dev_name);
247 static void ffs_release_dev(struct ffs_data *ffs_data);
248 static int ffs_ready(struct ffs_data *ffs);
249 static void ffs_closed(struct ffs_data *ffs);
250
251 /* Misc helper functions ****************************************************/
252
253 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
254 __attribute__((warn_unused_result, nonnull));
255 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
256 __attribute__((warn_unused_result, nonnull));
257
258
259 /* Control file aka ep0 *****************************************************/
260
261 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
262 {
263 struct ffs_data *ffs = req->context;
264
265 complete(&ffs->ep0req_completion);
266 }
267
268 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
269 __releases(&ffs->ev.waitq.lock)
270 {
271 struct usb_request *req = ffs->ep0req;
272 int ret;
273
274 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
275
276 spin_unlock_irq(&ffs->ev.waitq.lock);
277
278 req->buf = data;
279 req->length = len;
280
281 /*
282 * UDC layer requires to provide a buffer even for ZLP, but should
283 * not use it at all. Let's provide some poisoned pointer to catch
284 * possible bug in the driver.
285 */
286 if (req->buf == NULL)
287 req->buf = (void *)0xDEADBABE;
288
289 reinit_completion(&ffs->ep0req_completion);
290
291 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
292 if (unlikely(ret < 0))
293 return ret;
294
295 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
296 if (unlikely(ret)) {
297 usb_ep_dequeue(ffs->gadget->ep0, req);
298 return -EINTR;
299 }
300
301 ffs->setup_state = FFS_NO_SETUP;
302 return req->status ? req->status : req->actual;
303 }
304
305 static int __ffs_ep0_stall(struct ffs_data *ffs)
306 {
307 if (ffs->ev.can_stall) {
308 pr_vdebug("ep0 stall\n");
309 usb_ep_set_halt(ffs->gadget->ep0);
310 ffs->setup_state = FFS_NO_SETUP;
311 return -EL2HLT;
312 } else {
313 pr_debug("bogus ep0 stall!\n");
314 return -ESRCH;
315 }
316 }
317
318 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
319 size_t len, loff_t *ptr)
320 {
321 struct ffs_data *ffs = file->private_data;
322 ssize_t ret;
323 char *data;
324
325 ENTER();
326
327 /* Fast check if setup was canceled */
328 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
329 return -EIDRM;
330
331 /* Acquire mutex */
332 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
333 if (unlikely(ret < 0))
334 return ret;
335
336 /* Check state */
337 switch (ffs->state) {
338 case FFS_READ_DESCRIPTORS:
339 case FFS_READ_STRINGS:
340 /* Copy data */
341 if (unlikely(len < 16)) {
342 ret = -EINVAL;
343 break;
344 }
345
346 data = ffs_prepare_buffer(buf, len);
347 if (IS_ERR(data)) {
348 ret = PTR_ERR(data);
349 break;
350 }
351
352 /* Handle data */
353 if (ffs->state == FFS_READ_DESCRIPTORS) {
354 pr_info("read descriptors\n");
355 ret = __ffs_data_got_descs(ffs, data, len);
356 if (unlikely(ret < 0))
357 break;
358
359 ffs->state = FFS_READ_STRINGS;
360 ret = len;
361 } else {
362 pr_info("read strings\n");
363 ret = __ffs_data_got_strings(ffs, data, len);
364 if (unlikely(ret < 0))
365 break;
366
367 ret = ffs_epfiles_create(ffs);
368 if (unlikely(ret)) {
369 ffs->state = FFS_CLOSING;
370 break;
371 }
372
373 ffs->state = FFS_ACTIVE;
374 mutex_unlock(&ffs->mutex);
375
376 ret = ffs_ready(ffs);
377 if (unlikely(ret < 0)) {
378 ffs->state = FFS_CLOSING;
379 return ret;
380 }
381
382 return len;
383 }
384 break;
385
386 case FFS_ACTIVE:
387 data = NULL;
388 /*
389 * We're called from user space, we can use _irq
390 * rather then _irqsave
391 */
392 spin_lock_irq(&ffs->ev.waitq.lock);
393 switch (ffs_setup_state_clear_cancelled(ffs)) {
394 case FFS_SETUP_CANCELLED:
395 ret = -EIDRM;
396 goto done_spin;
397
398 case FFS_NO_SETUP:
399 ret = -ESRCH;
400 goto done_spin;
401
402 case FFS_SETUP_PENDING:
403 break;
404 }
405
406 /* FFS_SETUP_PENDING */
407 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
408 spin_unlock_irq(&ffs->ev.waitq.lock);
409 ret = __ffs_ep0_stall(ffs);
410 break;
411 }
412
413 /* FFS_SETUP_PENDING and not stall */
414 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
415
416 spin_unlock_irq(&ffs->ev.waitq.lock);
417
418 data = ffs_prepare_buffer(buf, len);
419 if (IS_ERR(data)) {
420 ret = PTR_ERR(data);
421 break;
422 }
423
424 spin_lock_irq(&ffs->ev.waitq.lock);
425
426 /*
427 * We are guaranteed to be still in FFS_ACTIVE state
428 * but the state of setup could have changed from
429 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
430 * to check for that. If that happened we copied data
431 * from user space in vain but it's unlikely.
432 *
433 * For sure we are not in FFS_NO_SETUP since this is
434 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
435 * transition can be performed and it's protected by
436 * mutex.
437 */
438 if (ffs_setup_state_clear_cancelled(ffs) ==
439 FFS_SETUP_CANCELLED) {
440 ret = -EIDRM;
441 done_spin:
442 spin_unlock_irq(&ffs->ev.waitq.lock);
443 } else {
444 /* unlocks spinlock */
445 ret = __ffs_ep0_queue_wait(ffs, data, len);
446 }
447 kfree(data);
448 break;
449
450 default:
451 ret = -EBADFD;
452 break;
453 }
454
455 mutex_unlock(&ffs->mutex);
456 return ret;
457 }
458
459 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
460 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
461 size_t n)
462 __releases(&ffs->ev.waitq.lock)
463 {
464 /*
465 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
466 * size of ffs->ev.types array (which is four) so that's how much space
467 * we reserve.
468 */
469 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
470 const size_t size = n * sizeof *events;
471 unsigned i = 0;
472
473 memset(events, 0, size);
474
475 do {
476 events[i].type = ffs->ev.types[i];
477 if (events[i].type == FUNCTIONFS_SETUP) {
478 events[i].u.setup = ffs->ev.setup;
479 ffs->setup_state = FFS_SETUP_PENDING;
480 }
481 } while (++i < n);
482
483 ffs->ev.count -= n;
484 if (ffs->ev.count)
485 memmove(ffs->ev.types, ffs->ev.types + n,
486 ffs->ev.count * sizeof *ffs->ev.types);
487
488 spin_unlock_irq(&ffs->ev.waitq.lock);
489 mutex_unlock(&ffs->mutex);
490
491 return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size;
492 }
493
494 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
495 size_t len, loff_t *ptr)
496 {
497 struct ffs_data *ffs = file->private_data;
498 char *data = NULL;
499 size_t n;
500 int ret;
501
502 ENTER();
503
504 /* Fast check if setup was canceled */
505 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
506 return -EIDRM;
507
508 /* Acquire mutex */
509 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
510 if (unlikely(ret < 0))
511 return ret;
512
513 /* Check state */
514 if (ffs->state != FFS_ACTIVE) {
515 ret = -EBADFD;
516 goto done_mutex;
517 }
518
519 /*
520 * We're called from user space, we can use _irq rather then
521 * _irqsave
522 */
523 spin_lock_irq(&ffs->ev.waitq.lock);
524
525 switch (ffs_setup_state_clear_cancelled(ffs)) {
526 case FFS_SETUP_CANCELLED:
527 ret = -EIDRM;
528 break;
529
530 case FFS_NO_SETUP:
531 n = len / sizeof(struct usb_functionfs_event);
532 if (unlikely(!n)) {
533 ret = -EINVAL;
534 break;
535 }
536
537 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
538 ret = -EAGAIN;
539 break;
540 }
541
542 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
543 ffs->ev.count)) {
544 ret = -EINTR;
545 break;
546 }
547
548 /* unlocks spinlock */
549 return __ffs_ep0_read_events(ffs, buf,
550 min(n, (size_t)ffs->ev.count));
551
552 case FFS_SETUP_PENDING:
553 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
554 spin_unlock_irq(&ffs->ev.waitq.lock);
555 ret = __ffs_ep0_stall(ffs);
556 goto done_mutex;
557 }
558
559 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
560
561 spin_unlock_irq(&ffs->ev.waitq.lock);
562
563 if (likely(len)) {
564 data = kmalloc(len, GFP_KERNEL);
565 if (unlikely(!data)) {
566 ret = -ENOMEM;
567 goto done_mutex;
568 }
569 }
570
571 spin_lock_irq(&ffs->ev.waitq.lock);
572
573 /* See ffs_ep0_write() */
574 if (ffs_setup_state_clear_cancelled(ffs) ==
575 FFS_SETUP_CANCELLED) {
576 ret = -EIDRM;
577 break;
578 }
579
580 /* unlocks spinlock */
581 ret = __ffs_ep0_queue_wait(ffs, data, len);
582 if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len)))
583 ret = -EFAULT;
584 goto done_mutex;
585
586 default:
587 ret = -EBADFD;
588 break;
589 }
590
591 spin_unlock_irq(&ffs->ev.waitq.lock);
592 done_mutex:
593 mutex_unlock(&ffs->mutex);
594 kfree(data);
595 return ret;
596 }
597
598 static int ffs_ep0_open(struct inode *inode, struct file *file)
599 {
600 struct ffs_data *ffs = inode->i_private;
601
602 ENTER();
603
604 if (unlikely(ffs->state == FFS_CLOSING))
605 return -EBUSY;
606
607 file->private_data = ffs;
608 ffs_data_opened(ffs);
609
610 return 0;
611 }
612
613 static int ffs_ep0_release(struct inode *inode, struct file *file)
614 {
615 struct ffs_data *ffs = file->private_data;
616
617 ENTER();
618
619 ffs_data_closed(ffs);
620
621 return 0;
622 }
623
624 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
625 {
626 struct ffs_data *ffs = file->private_data;
627 struct usb_gadget *gadget = ffs->gadget;
628 long ret;
629
630 ENTER();
631
632 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
633 struct ffs_function *func = ffs->func;
634 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
635 } else if (gadget && gadget->ops->ioctl) {
636 ret = gadget->ops->ioctl(gadget, code, value);
637 } else {
638 ret = -ENOTTY;
639 }
640
641 return ret;
642 }
643
644 static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait)
645 {
646 struct ffs_data *ffs = file->private_data;
647 __poll_t mask = EPOLLWRNORM;
648 int ret;
649
650 poll_wait(file, &ffs->ev.waitq, wait);
651
652 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
653 if (unlikely(ret < 0))
654 return mask;
655
656 switch (ffs->state) {
657 case FFS_READ_DESCRIPTORS:
658 case FFS_READ_STRINGS:
659 mask |= EPOLLOUT;
660 break;
661
662 case FFS_ACTIVE:
663 switch (ffs->setup_state) {
664 case FFS_NO_SETUP:
665 if (ffs->ev.count)
666 mask |= EPOLLIN;
667 break;
668
669 case FFS_SETUP_PENDING:
670 case FFS_SETUP_CANCELLED:
671 mask |= (EPOLLIN | EPOLLOUT);
672 break;
673 }
674 case FFS_CLOSING:
675 break;
676 case FFS_DEACTIVATED:
677 break;
678 }
679
680 mutex_unlock(&ffs->mutex);
681
682 return mask;
683 }
684
685 static const struct file_operations ffs_ep0_operations = {
686 .llseek = no_llseek,
687
688 .open = ffs_ep0_open,
689 .write = ffs_ep0_write,
690 .read = ffs_ep0_read,
691 .release = ffs_ep0_release,
692 .unlocked_ioctl = ffs_ep0_ioctl,
693 .poll = ffs_ep0_poll,
694 };
695
696
697 /* "Normal" endpoints operations ********************************************/
698
699 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
700 {
701 ENTER();
702 if (likely(req->context)) {
703 struct ffs_ep *ep = _ep->driver_data;
704 ep->status = req->status ? req->status : req->actual;
705 complete(req->context);
706 }
707 }
708
709 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter)
710 {
711 ssize_t ret = copy_to_iter(data, data_len, iter);
712 if (likely(ret == data_len))
713 return ret;
714
715 if (unlikely(iov_iter_count(iter)))
716 return -EFAULT;
717
718 /*
719 * Dear user space developer!
720 *
721 * TL;DR: To stop getting below error message in your kernel log, change
722 * user space code using functionfs to align read buffers to a max
723 * packet size.
724 *
725 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max
726 * packet size. When unaligned buffer is passed to functionfs, it
727 * internally uses a larger, aligned buffer so that such UDCs are happy.
728 *
729 * Unfortunately, this means that host may send more data than was
730 * requested in read(2) system call. f_fs doesn’t know what to do with
731 * that excess data so it simply drops it.
732 *
733 * Was the buffer aligned in the first place, no such problem would
734 * happen.
735 *
736 * Data may be dropped only in AIO reads. Synchronous reads are handled
737 * by splitting a request into multiple parts. This splitting may still
738 * be a problem though so it’s likely best to align the buffer
739 * regardless of it being AIO or not..
740 *
741 * This only affects OUT endpoints, i.e. reading data with a read(2),
742 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not
743 * affected.
744 */
745 pr_err("functionfs read size %d > requested size %zd, dropping excess data. "
746 "Align read buffer size to max packet size to avoid the problem.\n",
747 data_len, ret);
748
749 return ret;
750 }
751
752 static void ffs_user_copy_worker(struct work_struct *work)
753 {
754 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
755 work);
756 int ret = io_data->req->status ? io_data->req->status :
757 io_data->req->actual;
758 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
759
760 if (io_data->read && ret > 0) {
761 use_mm(io_data->mm);
762 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
763 unuse_mm(io_data->mm);
764 }
765
766 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
767
768 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
769 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
770
771 usb_ep_free_request(io_data->ep, io_data->req);
772
773 if (io_data->read)
774 kfree(io_data->to_free);
775 kfree(io_data->buf);
776 kfree(io_data);
777 }
778
779 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
780 struct usb_request *req)
781 {
782 struct ffs_io_data *io_data = req->context;
783 struct ffs_data *ffs = io_data->ffs;
784
785 ENTER();
786
787 INIT_WORK(&io_data->work, ffs_user_copy_worker);
788 queue_work(ffs->io_completion_wq, &io_data->work);
789 }
790
791 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile)
792 {
793 /*
794 * See comment in struct ffs_epfile for full read_buffer pointer
795 * synchronisation story.
796 */
797 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP);
798 if (buf && buf != READ_BUFFER_DROP)
799 kfree(buf);
800 }
801
802 /* Assumes epfile->mutex is held. */
803 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile,
804 struct iov_iter *iter)
805 {
806 /*
807 * Null out epfile->read_buffer so ffs_func_eps_disable does not free
808 * the buffer while we are using it. See comment in struct ffs_epfile
809 * for full read_buffer pointer synchronisation story.
810 */
811 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL);
812 ssize_t ret;
813 if (!buf || buf == READ_BUFFER_DROP)
814 return 0;
815
816 ret = copy_to_iter(buf->data, buf->length, iter);
817 if (buf->length == ret) {
818 kfree(buf);
819 return ret;
820 }
821
822 if (unlikely(iov_iter_count(iter))) {
823 ret = -EFAULT;
824 } else {
825 buf->length -= ret;
826 buf->data += ret;
827 }
828
829 if (cmpxchg(&epfile->read_buffer, NULL, buf))
830 kfree(buf);
831
832 return ret;
833 }
834
835 /* Assumes epfile->mutex is held. */
836 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile,
837 void *data, int data_len,
838 struct iov_iter *iter)
839 {
840 struct ffs_buffer *buf;
841
842 ssize_t ret = copy_to_iter(data, data_len, iter);
843 if (likely(data_len == ret))
844 return ret;
845
846 if (unlikely(iov_iter_count(iter)))
847 return -EFAULT;
848
849 /* See ffs_copy_to_iter for more context. */
850 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.",
851 data_len, ret);
852
853 data_len -= ret;
854 buf = kmalloc(sizeof(*buf) + data_len, GFP_KERNEL);
855 if (!buf)
856 return -ENOMEM;
857 buf->length = data_len;
858 buf->data = buf->storage;
859 memcpy(buf->storage, data + ret, data_len);
860
861 /*
862 * At this point read_buffer is NULL or READ_BUFFER_DROP (if
863 * ffs_func_eps_disable has been called in the meanwhile). See comment
864 * in struct ffs_epfile for full read_buffer pointer synchronisation
865 * story.
866 */
867 if (unlikely(cmpxchg(&epfile->read_buffer, NULL, buf)))
868 kfree(buf);
869
870 return ret;
871 }
872
873 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
874 {
875 struct ffs_epfile *epfile = file->private_data;
876 struct usb_request *req;
877 struct ffs_ep *ep;
878 char *data = NULL;
879 ssize_t ret, data_len = -EINVAL;
880 int halt;
881
882 /* Are we still active? */
883 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
884 return -ENODEV;
885
886 /* Wait for endpoint to be enabled */
887 ep = epfile->ep;
888 if (!ep) {
889 if (file->f_flags & O_NONBLOCK)
890 return -EAGAIN;
891
892 ret = wait_event_interruptible(
893 epfile->ffs->wait, (ep = epfile->ep));
894 if (ret)
895 return -EINTR;
896 }
897
898 /* Do we halt? */
899 halt = (!io_data->read == !epfile->in);
900 if (halt && epfile->isoc)
901 return -EINVAL;
902
903 /* We will be using request and read_buffer */
904 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
905 if (unlikely(ret))
906 goto error;
907
908 /* Allocate & copy */
909 if (!halt) {
910 struct usb_gadget *gadget;
911
912 /*
913 * Do we have buffered data from previous partial read? Check
914 * that for synchronous case only because we do not have
915 * facility to ‘wake up’ a pending asynchronous read and push
916 * buffered data to it which we would need to make things behave
917 * consistently.
918 */
919 if (!io_data->aio && io_data->read) {
920 ret = __ffs_epfile_read_buffered(epfile, &io_data->data);
921 if (ret)
922 goto error_mutex;
923 }
924
925 /*
926 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
927 * before the waiting completes, so do not assign to 'gadget'
928 * earlier
929 */
930 gadget = epfile->ffs->gadget;
931
932 spin_lock_irq(&epfile->ffs->eps_lock);
933 /* In the meantime, endpoint got disabled or changed. */
934 if (epfile->ep != ep) {
935 ret = -ESHUTDOWN;
936 goto error_lock;
937 }
938 data_len = iov_iter_count(&io_data->data);
939 /*
940 * Controller may require buffer size to be aligned to
941 * maxpacketsize of an out endpoint.
942 */
943 if (io_data->read)
944 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
945 spin_unlock_irq(&epfile->ffs->eps_lock);
946
947 data = kmalloc(data_len, GFP_KERNEL);
948 if (unlikely(!data)) {
949 ret = -ENOMEM;
950 goto error_mutex;
951 }
952 if (!io_data->read &&
953 !copy_from_iter_full(data, data_len, &io_data->data)) {
954 ret = -EFAULT;
955 goto error_mutex;
956 }
957 }
958
959 spin_lock_irq(&epfile->ffs->eps_lock);
960
961 if (epfile->ep != ep) {
962 /* In the meantime, endpoint got disabled or changed. */
963 ret = -ESHUTDOWN;
964 } else if (halt) {
965 ret = usb_ep_set_halt(ep->ep);
966 if (!ret)
967 ret = -EBADMSG;
968 } else if (unlikely(data_len == -EINVAL)) {
969 /*
970 * Sanity Check: even though data_len can't be used
971 * uninitialized at the time I write this comment, some
972 * compilers complain about this situation.
973 * In order to keep the code clean from warnings, data_len is
974 * being initialized to -EINVAL during its declaration, which
975 * means we can't rely on compiler anymore to warn no future
976 * changes won't result in data_len being used uninitialized.
977 * For such reason, we're adding this redundant sanity check
978 * here.
979 */
980 WARN(1, "%s: data_len == -EINVAL\n", __func__);
981 ret = -EINVAL;
982 } else if (!io_data->aio) {
983 DECLARE_COMPLETION_ONSTACK(done);
984 bool interrupted = false;
985
986 req = ep->req;
987 req->buf = data;
988 req->length = data_len;
989
990 req->context = &done;
991 req->complete = ffs_epfile_io_complete;
992
993 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
994 if (unlikely(ret < 0))
995 goto error_lock;
996
997 spin_unlock_irq(&epfile->ffs->eps_lock);
998
999 if (unlikely(wait_for_completion_interruptible(&done))) {
1000 /*
1001 * To avoid race condition with ffs_epfile_io_complete,
1002 * dequeue the request first then check
1003 * status. usb_ep_dequeue API should guarantee no race
1004 * condition with req->complete callback.
1005 */
1006 usb_ep_dequeue(ep->ep, req);
1007 interrupted = ep->status < 0;
1008 }
1009
1010 if (interrupted)
1011 ret = -EINTR;
1012 else if (io_data->read && ep->status > 0)
1013 ret = __ffs_epfile_read_data(epfile, data, ep->status,
1014 &io_data->data);
1015 else
1016 ret = ep->status;
1017 goto error_mutex;
1018 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) {
1019 ret = -ENOMEM;
1020 } else {
1021 req->buf = data;
1022 req->length = data_len;
1023
1024 io_data->buf = data;
1025 io_data->ep = ep->ep;
1026 io_data->req = req;
1027 io_data->ffs = epfile->ffs;
1028
1029 req->context = io_data;
1030 req->complete = ffs_epfile_async_io_complete;
1031
1032 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1033 if (unlikely(ret)) {
1034 usb_ep_free_request(ep->ep, req);
1035 goto error_lock;
1036 }
1037
1038 ret = -EIOCBQUEUED;
1039 /*
1040 * Do not kfree the buffer in this function. It will be freed
1041 * by ffs_user_copy_worker.
1042 */
1043 data = NULL;
1044 }
1045
1046 error_lock:
1047 spin_unlock_irq(&epfile->ffs->eps_lock);
1048 error_mutex:
1049 mutex_unlock(&epfile->mutex);
1050 error:
1051 kfree(data);
1052 return ret;
1053 }
1054
1055 static int
1056 ffs_epfile_open(struct inode *inode, struct file *file)
1057 {
1058 struct ffs_epfile *epfile = inode->i_private;
1059
1060 ENTER();
1061
1062 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1063 return -ENODEV;
1064
1065 file->private_data = epfile;
1066 ffs_data_opened(epfile->ffs);
1067
1068 return 0;
1069 }
1070
1071 static int ffs_aio_cancel(struct kiocb *kiocb)
1072 {
1073 struct ffs_io_data *io_data = kiocb->private;
1074 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
1075 int value;
1076
1077 ENTER();
1078
1079 spin_lock_irq(&epfile->ffs->eps_lock);
1080
1081 if (likely(io_data && io_data->ep && io_data->req))
1082 value = usb_ep_dequeue(io_data->ep, io_data->req);
1083 else
1084 value = -EINVAL;
1085
1086 spin_unlock_irq(&epfile->ffs->eps_lock);
1087
1088 return value;
1089 }
1090
1091 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
1092 {
1093 struct ffs_io_data io_data, *p = &io_data;
1094 ssize_t res;
1095
1096 ENTER();
1097
1098 if (!is_sync_kiocb(kiocb)) {
1099 p = kmalloc(sizeof(io_data), GFP_KERNEL);
1100 if (unlikely(!p))
1101 return -ENOMEM;
1102 p->aio = true;
1103 } else {
1104 p->aio = false;
1105 }
1106
1107 p->read = false;
1108 p->kiocb = kiocb;
1109 p->data = *from;
1110 p->mm = current->mm;
1111
1112 kiocb->private = p;
1113
1114 if (p->aio)
1115 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1116
1117 res = ffs_epfile_io(kiocb->ki_filp, p);
1118 if (res == -EIOCBQUEUED)
1119 return res;
1120 if (p->aio)
1121 kfree(p);
1122 else
1123 *from = p->data;
1124 return res;
1125 }
1126
1127 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
1128 {
1129 struct ffs_io_data io_data, *p = &io_data;
1130 ssize_t res;
1131
1132 ENTER();
1133
1134 if (!is_sync_kiocb(kiocb)) {
1135 p = kmalloc(sizeof(io_data), GFP_KERNEL);
1136 if (unlikely(!p))
1137 return -ENOMEM;
1138 p->aio = true;
1139 } else {
1140 p->aio = false;
1141 }
1142
1143 p->read = true;
1144 p->kiocb = kiocb;
1145 if (p->aio) {
1146 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
1147 if (!p->to_free) {
1148 kfree(p);
1149 return -ENOMEM;
1150 }
1151 } else {
1152 p->data = *to;
1153 p->to_free = NULL;
1154 }
1155 p->mm = current->mm;
1156
1157 kiocb->private = p;
1158
1159 if (p->aio)
1160 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1161
1162 res = ffs_epfile_io(kiocb->ki_filp, p);
1163 if (res == -EIOCBQUEUED)
1164 return res;
1165
1166 if (p->aio) {
1167 kfree(p->to_free);
1168 kfree(p);
1169 } else {
1170 *to = p->data;
1171 }
1172 return res;
1173 }
1174
1175 static int
1176 ffs_epfile_release(struct inode *inode, struct file *file)
1177 {
1178 struct ffs_epfile *epfile = inode->i_private;
1179
1180 ENTER();
1181
1182 __ffs_epfile_read_buffer_free(epfile);
1183 ffs_data_closed(epfile->ffs);
1184
1185 return 0;
1186 }
1187
1188 static long ffs_epfile_ioctl(struct file *file, unsigned code,
1189 unsigned long value)
1190 {
1191 struct ffs_epfile *epfile = file->private_data;
1192 struct ffs_ep *ep;
1193 int ret;
1194
1195 ENTER();
1196
1197 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1198 return -ENODEV;
1199
1200 /* Wait for endpoint to be enabled */
1201 ep = epfile->ep;
1202 if (!ep) {
1203 if (file->f_flags & O_NONBLOCK)
1204 return -EAGAIN;
1205
1206 ret = wait_event_interruptible(
1207 epfile->ffs->wait, (ep = epfile->ep));
1208 if (ret)
1209 return -EINTR;
1210 }
1211
1212 spin_lock_irq(&epfile->ffs->eps_lock);
1213
1214 /* In the meantime, endpoint got disabled or changed. */
1215 if (epfile->ep != ep) {
1216 spin_unlock_irq(&epfile->ffs->eps_lock);
1217 return -ESHUTDOWN;
1218 }
1219
1220 switch (code) {
1221 case FUNCTIONFS_FIFO_STATUS:
1222 ret = usb_ep_fifo_status(epfile->ep->ep);
1223 break;
1224 case FUNCTIONFS_FIFO_FLUSH:
1225 usb_ep_fifo_flush(epfile->ep->ep);
1226 ret = 0;
1227 break;
1228 case FUNCTIONFS_CLEAR_HALT:
1229 ret = usb_ep_clear_halt(epfile->ep->ep);
1230 break;
1231 case FUNCTIONFS_ENDPOINT_REVMAP:
1232 ret = epfile->ep->num;
1233 break;
1234 case FUNCTIONFS_ENDPOINT_DESC:
1235 {
1236 int desc_idx;
1237 struct usb_endpoint_descriptor *desc;
1238
1239 switch (epfile->ffs->gadget->speed) {
1240 case USB_SPEED_SUPER:
1241 desc_idx = 2;
1242 break;
1243 case USB_SPEED_HIGH:
1244 desc_idx = 1;
1245 break;
1246 default:
1247 desc_idx = 0;
1248 }
1249 desc = epfile->ep->descs[desc_idx];
1250
1251 spin_unlock_irq(&epfile->ffs->eps_lock);
1252 ret = copy_to_user((void __user *)value, desc, desc->bLength);
1253 if (ret)
1254 ret = -EFAULT;
1255 return ret;
1256 }
1257 default:
1258 ret = -ENOTTY;
1259 }
1260 spin_unlock_irq(&epfile->ffs->eps_lock);
1261
1262 return ret;
1263 }
1264
1265 static const struct file_operations ffs_epfile_operations = {
1266 .llseek = no_llseek,
1267
1268 .open = ffs_epfile_open,
1269 .write_iter = ffs_epfile_write_iter,
1270 .read_iter = ffs_epfile_read_iter,
1271 .release = ffs_epfile_release,
1272 .unlocked_ioctl = ffs_epfile_ioctl,
1273 };
1274
1275
1276 /* File system and super block operations ***********************************/
1277
1278 /*
1279 * Mounting the file system creates a controller file, used first for
1280 * function configuration then later for event monitoring.
1281 */
1282
1283 static struct inode *__must_check
1284 ffs_sb_make_inode(struct super_block *sb, void *data,
1285 const struct file_operations *fops,
1286 const struct inode_operations *iops,
1287 struct ffs_file_perms *perms)
1288 {
1289 struct inode *inode;
1290
1291 ENTER();
1292
1293 inode = new_inode(sb);
1294
1295 if (likely(inode)) {
1296 struct timespec ts = current_time(inode);
1297
1298 inode->i_ino = get_next_ino();
1299 inode->i_mode = perms->mode;
1300 inode->i_uid = perms->uid;
1301 inode->i_gid = perms->gid;
1302 inode->i_atime = ts;
1303 inode->i_mtime = ts;
1304 inode->i_ctime = ts;
1305 inode->i_private = data;
1306 if (fops)
1307 inode->i_fop = fops;
1308 if (iops)
1309 inode->i_op = iops;
1310 }
1311
1312 return inode;
1313 }
1314
1315 /* Create "regular" file */
1316 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1317 const char *name, void *data,
1318 const struct file_operations *fops)
1319 {
1320 struct ffs_data *ffs = sb->s_fs_info;
1321 struct dentry *dentry;
1322 struct inode *inode;
1323
1324 ENTER();
1325
1326 dentry = d_alloc_name(sb->s_root, name);
1327 if (unlikely(!dentry))
1328 return NULL;
1329
1330 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1331 if (unlikely(!inode)) {
1332 dput(dentry);
1333 return NULL;
1334 }
1335
1336 d_add(dentry, inode);
1337 return dentry;
1338 }
1339
1340 /* Super block */
1341 static const struct super_operations ffs_sb_operations = {
1342 .statfs = simple_statfs,
1343 .drop_inode = generic_delete_inode,
1344 };
1345
1346 struct ffs_sb_fill_data {
1347 struct ffs_file_perms perms;
1348 umode_t root_mode;
1349 const char *dev_name;
1350 bool no_disconnect;
1351 struct ffs_data *ffs_data;
1352 };
1353
1354 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1355 {
1356 struct ffs_sb_fill_data *data = _data;
1357 struct inode *inode;
1358 struct ffs_data *ffs = data->ffs_data;
1359
1360 ENTER();
1361
1362 ffs->sb = sb;
1363 data->ffs_data = NULL;
1364 sb->s_fs_info = ffs;
1365 sb->s_blocksize = PAGE_SIZE;
1366 sb->s_blocksize_bits = PAGE_SHIFT;
1367 sb->s_magic = FUNCTIONFS_MAGIC;
1368 sb->s_op = &ffs_sb_operations;
1369 sb->s_time_gran = 1;
1370
1371 /* Root inode */
1372 data->perms.mode = data->root_mode;
1373 inode = ffs_sb_make_inode(sb, NULL,
1374 &simple_dir_operations,
1375 &simple_dir_inode_operations,
1376 &data->perms);
1377 sb->s_root = d_make_root(inode);
1378 if (unlikely(!sb->s_root))
1379 return -ENOMEM;
1380
1381 /* EP0 file */
1382 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1383 &ffs_ep0_operations)))
1384 return -ENOMEM;
1385
1386 return 0;
1387 }
1388
1389 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1390 {
1391 ENTER();
1392
1393 if (!opts || !*opts)
1394 return 0;
1395
1396 for (;;) {
1397 unsigned long value;
1398 char *eq, *comma;
1399
1400 /* Option limit */
1401 comma = strchr(opts, ',');
1402 if (comma)
1403 *comma = 0;
1404
1405 /* Value limit */
1406 eq = strchr(opts, '=');
1407 if (unlikely(!eq)) {
1408 pr_err("'=' missing in %s\n", opts);
1409 return -EINVAL;
1410 }
1411 *eq = 0;
1412
1413 /* Parse value */
1414 if (kstrtoul(eq + 1, 0, &value)) {
1415 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1416 return -EINVAL;
1417 }
1418
1419 /* Interpret option */
1420 switch (eq - opts) {
1421 case 13:
1422 if (!memcmp(opts, "no_disconnect", 13))
1423 data->no_disconnect = !!value;
1424 else
1425 goto invalid;
1426 break;
1427 case 5:
1428 if (!memcmp(opts, "rmode", 5))
1429 data->root_mode = (value & 0555) | S_IFDIR;
1430 else if (!memcmp(opts, "fmode", 5))
1431 data->perms.mode = (value & 0666) | S_IFREG;
1432 else
1433 goto invalid;
1434 break;
1435
1436 case 4:
1437 if (!memcmp(opts, "mode", 4)) {
1438 data->root_mode = (value & 0555) | S_IFDIR;
1439 data->perms.mode = (value & 0666) | S_IFREG;
1440 } else {
1441 goto invalid;
1442 }
1443 break;
1444
1445 case 3:
1446 if (!memcmp(opts, "uid", 3)) {
1447 data->perms.uid = make_kuid(current_user_ns(), value);
1448 if (!uid_valid(data->perms.uid)) {
1449 pr_err("%s: unmapped value: %lu\n", opts, value);
1450 return -EINVAL;
1451 }
1452 } else if (!memcmp(opts, "gid", 3)) {
1453 data->perms.gid = make_kgid(current_user_ns(), value);
1454 if (!gid_valid(data->perms.gid)) {
1455 pr_err("%s: unmapped value: %lu\n", opts, value);
1456 return -EINVAL;
1457 }
1458 } else {
1459 goto invalid;
1460 }
1461 break;
1462
1463 default:
1464 invalid:
1465 pr_err("%s: invalid option\n", opts);
1466 return -EINVAL;
1467 }
1468
1469 /* Next iteration */
1470 if (!comma)
1471 break;
1472 opts = comma + 1;
1473 }
1474
1475 return 0;
1476 }
1477
1478 /* "mount -t functionfs dev_name /dev/function" ends up here */
1479
1480 static struct dentry *
1481 ffs_fs_mount(struct file_system_type *t, int flags,
1482 const char *dev_name, void *opts)
1483 {
1484 struct ffs_sb_fill_data data = {
1485 .perms = {
1486 .mode = S_IFREG | 0600,
1487 .uid = GLOBAL_ROOT_UID,
1488 .gid = GLOBAL_ROOT_GID,
1489 },
1490 .root_mode = S_IFDIR | 0500,
1491 .no_disconnect = false,
1492 };
1493 struct dentry *rv;
1494 int ret;
1495 void *ffs_dev;
1496 struct ffs_data *ffs;
1497
1498 ENTER();
1499
1500 ret = ffs_fs_parse_opts(&data, opts);
1501 if (unlikely(ret < 0))
1502 return ERR_PTR(ret);
1503
1504 ffs = ffs_data_new(dev_name);
1505 if (unlikely(!ffs))
1506 return ERR_PTR(-ENOMEM);
1507 ffs->file_perms = data.perms;
1508 ffs->no_disconnect = data.no_disconnect;
1509
1510 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1511 if (unlikely(!ffs->dev_name)) {
1512 ffs_data_put(ffs);
1513 return ERR_PTR(-ENOMEM);
1514 }
1515
1516 ffs_dev = ffs_acquire_dev(dev_name);
1517 if (IS_ERR(ffs_dev)) {
1518 ffs_data_put(ffs);
1519 return ERR_CAST(ffs_dev);
1520 }
1521 ffs->private_data = ffs_dev;
1522 data.ffs_data = ffs;
1523
1524 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1525 if (IS_ERR(rv) && data.ffs_data) {
1526 ffs_release_dev(data.ffs_data);
1527 ffs_data_put(data.ffs_data);
1528 }
1529 return rv;
1530 }
1531
1532 static void
1533 ffs_fs_kill_sb(struct super_block *sb)
1534 {
1535 ENTER();
1536
1537 kill_litter_super(sb);
1538 if (sb->s_fs_info) {
1539 ffs_release_dev(sb->s_fs_info);
1540 ffs_data_closed(sb->s_fs_info);
1541 ffs_data_put(sb->s_fs_info);
1542 }
1543 }
1544
1545 static struct file_system_type ffs_fs_type = {
1546 .owner = THIS_MODULE,
1547 .name = "functionfs",
1548 .mount = ffs_fs_mount,
1549 .kill_sb = ffs_fs_kill_sb,
1550 };
1551 MODULE_ALIAS_FS("functionfs");
1552
1553
1554 /* Driver's main init/cleanup functions *************************************/
1555
1556 static int functionfs_init(void)
1557 {
1558 int ret;
1559
1560 ENTER();
1561
1562 ret = register_filesystem(&ffs_fs_type);
1563 if (likely(!ret))
1564 pr_info("file system registered\n");
1565 else
1566 pr_err("failed registering file system (%d)\n", ret);
1567
1568 return ret;
1569 }
1570
1571 static void functionfs_cleanup(void)
1572 {
1573 ENTER();
1574
1575 pr_info("unloading\n");
1576 unregister_filesystem(&ffs_fs_type);
1577 }
1578
1579
1580 /* ffs_data and ffs_function construction and destruction code **************/
1581
1582 static void ffs_data_clear(struct ffs_data *ffs);
1583 static void ffs_data_reset(struct ffs_data *ffs);
1584
1585 static void ffs_data_get(struct ffs_data *ffs)
1586 {
1587 ENTER();
1588
1589 refcount_inc(&ffs->ref);
1590 }
1591
1592 static void ffs_data_opened(struct ffs_data *ffs)
1593 {
1594 ENTER();
1595
1596 refcount_inc(&ffs->ref);
1597 if (atomic_add_return(1, &ffs->opened) == 1 &&
1598 ffs->state == FFS_DEACTIVATED) {
1599 ffs->state = FFS_CLOSING;
1600 ffs_data_reset(ffs);
1601 }
1602 }
1603
1604 static void ffs_data_put(struct ffs_data *ffs)
1605 {
1606 ENTER();
1607
1608 if (unlikely(refcount_dec_and_test(&ffs->ref))) {
1609 pr_info("%s(): freeing\n", __func__);
1610 ffs_data_clear(ffs);
1611 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1612 waitqueue_active(&ffs->ep0req_completion.wait) ||
1613 waitqueue_active(&ffs->wait));
1614 destroy_workqueue(ffs->io_completion_wq);
1615 kfree(ffs->dev_name);
1616 kfree(ffs);
1617 }
1618 }
1619
1620 static void ffs_data_closed(struct ffs_data *ffs)
1621 {
1622 ENTER();
1623
1624 if (atomic_dec_and_test(&ffs->opened)) {
1625 if (ffs->no_disconnect) {
1626 ffs->state = FFS_DEACTIVATED;
1627 if (ffs->epfiles) {
1628 ffs_epfiles_destroy(ffs->epfiles,
1629 ffs->eps_count);
1630 ffs->epfiles = NULL;
1631 }
1632 if (ffs->setup_state == FFS_SETUP_PENDING)
1633 __ffs_ep0_stall(ffs);
1634 } else {
1635 ffs->state = FFS_CLOSING;
1636 ffs_data_reset(ffs);
1637 }
1638 }
1639 if (atomic_read(&ffs->opened) < 0) {
1640 ffs->state = FFS_CLOSING;
1641 ffs_data_reset(ffs);
1642 }
1643
1644 ffs_data_put(ffs);
1645 }
1646
1647 static struct ffs_data *ffs_data_new(const char *dev_name)
1648 {
1649 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1650 if (unlikely(!ffs))
1651 return NULL;
1652
1653 ENTER();
1654
1655 ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name);
1656 if (!ffs->io_completion_wq) {
1657 kfree(ffs);
1658 return NULL;
1659 }
1660
1661 refcount_set(&ffs->ref, 1);
1662 atomic_set(&ffs->opened, 0);
1663 ffs->state = FFS_READ_DESCRIPTORS;
1664 mutex_init(&ffs->mutex);
1665 spin_lock_init(&ffs->eps_lock);
1666 init_waitqueue_head(&ffs->ev.waitq);
1667 init_waitqueue_head(&ffs->wait);
1668 init_completion(&ffs->ep0req_completion);
1669
1670 /* XXX REVISIT need to update it in some places, or do we? */
1671 ffs->ev.can_stall = 1;
1672
1673 return ffs;
1674 }
1675
1676 static void ffs_data_clear(struct ffs_data *ffs)
1677 {
1678 ENTER();
1679
1680 ffs_closed(ffs);
1681
1682 BUG_ON(ffs->gadget);
1683
1684 if (ffs->epfiles)
1685 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1686
1687 if (ffs->ffs_eventfd)
1688 eventfd_ctx_put(ffs->ffs_eventfd);
1689
1690 kfree(ffs->raw_descs_data);
1691 kfree(ffs->raw_strings);
1692 kfree(ffs->stringtabs);
1693 }
1694
1695 static void ffs_data_reset(struct ffs_data *ffs)
1696 {
1697 ENTER();
1698
1699 ffs_data_clear(ffs);
1700
1701 ffs->epfiles = NULL;
1702 ffs->raw_descs_data = NULL;
1703 ffs->raw_descs = NULL;
1704 ffs->raw_strings = NULL;
1705 ffs->stringtabs = NULL;
1706
1707 ffs->raw_descs_length = 0;
1708 ffs->fs_descs_count = 0;
1709 ffs->hs_descs_count = 0;
1710 ffs->ss_descs_count = 0;
1711
1712 ffs->strings_count = 0;
1713 ffs->interfaces_count = 0;
1714 ffs->eps_count = 0;
1715
1716 ffs->ev.count = 0;
1717
1718 ffs->state = FFS_READ_DESCRIPTORS;
1719 ffs->setup_state = FFS_NO_SETUP;
1720 ffs->flags = 0;
1721 }
1722
1723
1724 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1725 {
1726 struct usb_gadget_strings **lang;
1727 int first_id;
1728
1729 ENTER();
1730
1731 if (WARN_ON(ffs->state != FFS_ACTIVE
1732 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1733 return -EBADFD;
1734
1735 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1736 if (unlikely(first_id < 0))
1737 return first_id;
1738
1739 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1740 if (unlikely(!ffs->ep0req))
1741 return -ENOMEM;
1742 ffs->ep0req->complete = ffs_ep0_complete;
1743 ffs->ep0req->context = ffs;
1744
1745 lang = ffs->stringtabs;
1746 if (lang) {
1747 for (; *lang; ++lang) {
1748 struct usb_string *str = (*lang)->strings;
1749 int id = first_id;
1750 for (; str->s; ++id, ++str)
1751 str->id = id;
1752 }
1753 }
1754
1755 ffs->gadget = cdev->gadget;
1756 ffs_data_get(ffs);
1757 return 0;
1758 }
1759
1760 static void functionfs_unbind(struct ffs_data *ffs)
1761 {
1762 ENTER();
1763
1764 if (!WARN_ON(!ffs->gadget)) {
1765 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1766 ffs->ep0req = NULL;
1767 ffs->gadget = NULL;
1768 clear_bit(FFS_FL_BOUND, &ffs->flags);
1769 ffs_data_put(ffs);
1770 }
1771 }
1772
1773 static int ffs_epfiles_create(struct ffs_data *ffs)
1774 {
1775 struct ffs_epfile *epfile, *epfiles;
1776 unsigned i, count;
1777
1778 ENTER();
1779
1780 count = ffs->eps_count;
1781 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1782 if (!epfiles)
1783 return -ENOMEM;
1784
1785 epfile = epfiles;
1786 for (i = 1; i <= count; ++i, ++epfile) {
1787 epfile->ffs = ffs;
1788 mutex_init(&epfile->mutex);
1789 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1790 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1791 else
1792 sprintf(epfile->name, "ep%u", i);
1793 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1794 epfile,
1795 &ffs_epfile_operations);
1796 if (unlikely(!epfile->dentry)) {
1797 ffs_epfiles_destroy(epfiles, i - 1);
1798 return -ENOMEM;
1799 }
1800 }
1801
1802 ffs->epfiles = epfiles;
1803 return 0;
1804 }
1805
1806 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1807 {
1808 struct ffs_epfile *epfile = epfiles;
1809
1810 ENTER();
1811
1812 for (; count; --count, ++epfile) {
1813 BUG_ON(mutex_is_locked(&epfile->mutex));
1814 if (epfile->dentry) {
1815 d_delete(epfile->dentry);
1816 dput(epfile->dentry);
1817 epfile->dentry = NULL;
1818 }
1819 }
1820
1821 kfree(epfiles);
1822 }
1823
1824 static void ffs_func_eps_disable(struct ffs_function *func)
1825 {
1826 struct ffs_ep *ep = func->eps;
1827 struct ffs_epfile *epfile = func->ffs->epfiles;
1828 unsigned count = func->ffs->eps_count;
1829 unsigned long flags;
1830
1831 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1832 while (count--) {
1833 /* pending requests get nuked */
1834 if (likely(ep->ep))
1835 usb_ep_disable(ep->ep);
1836 ++ep;
1837
1838 if (epfile) {
1839 epfile->ep = NULL;
1840 __ffs_epfile_read_buffer_free(epfile);
1841 ++epfile;
1842 }
1843 }
1844 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1845 }
1846
1847 static int ffs_func_eps_enable(struct ffs_function *func)
1848 {
1849 struct ffs_data *ffs = func->ffs;
1850 struct ffs_ep *ep = func->eps;
1851 struct ffs_epfile *epfile = ffs->epfiles;
1852 unsigned count = ffs->eps_count;
1853 unsigned long flags;
1854 int ret = 0;
1855
1856 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1857 while(count--) {
1858 ep->ep->driver_data = ep;
1859
1860 ret = config_ep_by_speed(func->gadget, &func->function, ep->ep);
1861 if (ret) {
1862 pr_err("%s: config_ep_by_speed(%s) returned %d\n",
1863 __func__, ep->ep->name, ret);
1864 break;
1865 }
1866
1867 ret = usb_ep_enable(ep->ep);
1868 if (likely(!ret)) {
1869 epfile->ep = ep;
1870 epfile->in = usb_endpoint_dir_in(ep->ep->desc);
1871 epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc);
1872 } else {
1873 break;
1874 }
1875
1876 ++ep;
1877 ++epfile;
1878 }
1879
1880 wake_up_interruptible(&ffs->wait);
1881 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1882
1883 return ret;
1884 }
1885
1886
1887 /* Parsing and building descriptors and strings *****************************/
1888
1889 /*
1890 * This validates if data pointed by data is a valid USB descriptor as
1891 * well as record how many interfaces, endpoints and strings are
1892 * required by given configuration. Returns address after the
1893 * descriptor or NULL if data is invalid.
1894 */
1895
1896 enum ffs_entity_type {
1897 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1898 };
1899
1900 enum ffs_os_desc_type {
1901 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1902 };
1903
1904 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1905 u8 *valuep,
1906 struct usb_descriptor_header *desc,
1907 void *priv);
1908
1909 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1910 struct usb_os_desc_header *h, void *data,
1911 unsigned len, void *priv);
1912
1913 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1914 ffs_entity_callback entity,
1915 void *priv)
1916 {
1917 struct usb_descriptor_header *_ds = (void *)data;
1918 u8 length;
1919 int ret;
1920
1921 ENTER();
1922
1923 /* At least two bytes are required: length and type */
1924 if (len < 2) {
1925 pr_vdebug("descriptor too short\n");
1926 return -EINVAL;
1927 }
1928
1929 /* If we have at least as many bytes as the descriptor takes? */
1930 length = _ds->bLength;
1931 if (len < length) {
1932 pr_vdebug("descriptor longer then available data\n");
1933 return -EINVAL;
1934 }
1935
1936 #define __entity_check_INTERFACE(val) 1
1937 #define __entity_check_STRING(val) (val)
1938 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1939 #define __entity(type, val) do { \
1940 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1941 if (unlikely(!__entity_check_ ##type(val))) { \
1942 pr_vdebug("invalid entity's value\n"); \
1943 return -EINVAL; \
1944 } \
1945 ret = entity(FFS_ ##type, &val, _ds, priv); \
1946 if (unlikely(ret < 0)) { \
1947 pr_debug("entity " #type "(%02x); ret = %d\n", \
1948 (val), ret); \
1949 return ret; \
1950 } \
1951 } while (0)
1952
1953 /* Parse descriptor depending on type. */
1954 switch (_ds->bDescriptorType) {
1955 case USB_DT_DEVICE:
1956 case USB_DT_CONFIG:
1957 case USB_DT_STRING:
1958 case USB_DT_DEVICE_QUALIFIER:
1959 /* function can't have any of those */
1960 pr_vdebug("descriptor reserved for gadget: %d\n",
1961 _ds->bDescriptorType);
1962 return -EINVAL;
1963
1964 case USB_DT_INTERFACE: {
1965 struct usb_interface_descriptor *ds = (void *)_ds;
1966 pr_vdebug("interface descriptor\n");
1967 if (length != sizeof *ds)
1968 goto inv_length;
1969
1970 __entity(INTERFACE, ds->bInterfaceNumber);
1971 if (ds->iInterface)
1972 __entity(STRING, ds->iInterface);
1973 }
1974 break;
1975
1976 case USB_DT_ENDPOINT: {
1977 struct usb_endpoint_descriptor *ds = (void *)_ds;
1978 pr_vdebug("endpoint descriptor\n");
1979 if (length != USB_DT_ENDPOINT_SIZE &&
1980 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1981 goto inv_length;
1982 __entity(ENDPOINT, ds->bEndpointAddress);
1983 }
1984 break;
1985
1986 case HID_DT_HID:
1987 pr_vdebug("hid descriptor\n");
1988 if (length != sizeof(struct hid_descriptor))
1989 goto inv_length;
1990 break;
1991
1992 case USB_DT_OTG:
1993 if (length != sizeof(struct usb_otg_descriptor))
1994 goto inv_length;
1995 break;
1996
1997 case USB_DT_INTERFACE_ASSOCIATION: {
1998 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1999 pr_vdebug("interface association descriptor\n");
2000 if (length != sizeof *ds)
2001 goto inv_length;
2002 if (ds->iFunction)
2003 __entity(STRING, ds->iFunction);
2004 }
2005 break;
2006
2007 case USB_DT_SS_ENDPOINT_COMP:
2008 pr_vdebug("EP SS companion descriptor\n");
2009 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
2010 goto inv_length;
2011 break;
2012
2013 case USB_DT_OTHER_SPEED_CONFIG:
2014 case USB_DT_INTERFACE_POWER:
2015 case USB_DT_DEBUG:
2016 case USB_DT_SECURITY:
2017 case USB_DT_CS_RADIO_CONTROL:
2018 /* TODO */
2019 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
2020 return -EINVAL;
2021
2022 default:
2023 /* We should never be here */
2024 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
2025 return -EINVAL;
2026
2027 inv_length:
2028 pr_vdebug("invalid length: %d (descriptor %d)\n",
2029 _ds->bLength, _ds->bDescriptorType);
2030 return -EINVAL;
2031 }
2032
2033 #undef __entity
2034 #undef __entity_check_DESCRIPTOR
2035 #undef __entity_check_INTERFACE
2036 #undef __entity_check_STRING
2037 #undef __entity_check_ENDPOINT
2038
2039 return length;
2040 }
2041
2042 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
2043 ffs_entity_callback entity, void *priv)
2044 {
2045 const unsigned _len = len;
2046 unsigned long num = 0;
2047
2048 ENTER();
2049
2050 for (;;) {
2051 int ret;
2052
2053 if (num == count)
2054 data = NULL;
2055
2056 /* Record "descriptor" entity */
2057 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
2058 if (unlikely(ret < 0)) {
2059 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
2060 num, ret);
2061 return ret;
2062 }
2063
2064 if (!data)
2065 return _len - len;
2066
2067 ret = ffs_do_single_desc(data, len, entity, priv);
2068 if (unlikely(ret < 0)) {
2069 pr_debug("%s returns %d\n", __func__, ret);
2070 return ret;
2071 }
2072
2073 len -= ret;
2074 data += ret;
2075 ++num;
2076 }
2077 }
2078
2079 static int __ffs_data_do_entity(enum ffs_entity_type type,
2080 u8 *valuep, struct usb_descriptor_header *desc,
2081 void *priv)
2082 {
2083 struct ffs_desc_helper *helper = priv;
2084 struct usb_endpoint_descriptor *d;
2085
2086 ENTER();
2087
2088 switch (type) {
2089 case FFS_DESCRIPTOR:
2090 break;
2091
2092 case FFS_INTERFACE:
2093 /*
2094 * Interfaces are indexed from zero so if we
2095 * encountered interface "n" then there are at least
2096 * "n+1" interfaces.
2097 */
2098 if (*valuep >= helper->interfaces_count)
2099 helper->interfaces_count = *valuep + 1;
2100 break;
2101
2102 case FFS_STRING:
2103 /*
2104 * Strings are indexed from 1 (0 is reserved
2105 * for languages list)
2106 */
2107 if (*valuep > helper->ffs->strings_count)
2108 helper->ffs->strings_count = *valuep;
2109 break;
2110
2111 case FFS_ENDPOINT:
2112 d = (void *)desc;
2113 helper->eps_count++;
2114 if (helper->eps_count >= FFS_MAX_EPS_COUNT)
2115 return -EINVAL;
2116 /* Check if descriptors for any speed were already parsed */
2117 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
2118 helper->ffs->eps_addrmap[helper->eps_count] =
2119 d->bEndpointAddress;
2120 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
2121 d->bEndpointAddress)
2122 return -EINVAL;
2123 break;
2124 }
2125
2126 return 0;
2127 }
2128
2129 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
2130 struct usb_os_desc_header *desc)
2131 {
2132 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
2133 u16 w_index = le16_to_cpu(desc->wIndex);
2134
2135 if (bcd_version != 1) {
2136 pr_vdebug("unsupported os descriptors version: %d",
2137 bcd_version);
2138 return -EINVAL;
2139 }
2140 switch (w_index) {
2141 case 0x4:
2142 *next_type = FFS_OS_DESC_EXT_COMPAT;
2143 break;
2144 case 0x5:
2145 *next_type = FFS_OS_DESC_EXT_PROP;
2146 break;
2147 default:
2148 pr_vdebug("unsupported os descriptor type: %d", w_index);
2149 return -EINVAL;
2150 }
2151
2152 return sizeof(*desc);
2153 }
2154
2155 /*
2156 * Process all extended compatibility/extended property descriptors
2157 * of a feature descriptor
2158 */
2159 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
2160 enum ffs_os_desc_type type,
2161 u16 feature_count,
2162 ffs_os_desc_callback entity,
2163 void *priv,
2164 struct usb_os_desc_header *h)
2165 {
2166 int ret;
2167 const unsigned _len = len;
2168
2169 ENTER();
2170
2171 /* loop over all ext compat/ext prop descriptors */
2172 while (feature_count--) {
2173 ret = entity(type, h, data, len, priv);
2174 if (unlikely(ret < 0)) {
2175 pr_debug("bad OS descriptor, type: %d\n", type);
2176 return ret;
2177 }
2178 data += ret;
2179 len -= ret;
2180 }
2181 return _len - len;
2182 }
2183
2184 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
2185 static int __must_check ffs_do_os_descs(unsigned count,
2186 char *data, unsigned len,
2187 ffs_os_desc_callback entity, void *priv)
2188 {
2189 const unsigned _len = len;
2190 unsigned long num = 0;
2191
2192 ENTER();
2193
2194 for (num = 0; num < count; ++num) {
2195 int ret;
2196 enum ffs_os_desc_type type;
2197 u16 feature_count;
2198 struct usb_os_desc_header *desc = (void *)data;
2199
2200 if (len < sizeof(*desc))
2201 return -EINVAL;
2202
2203 /*
2204 * Record "descriptor" entity.
2205 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2206 * Move the data pointer to the beginning of extended
2207 * compatibilities proper or extended properties proper
2208 * portions of the data
2209 */
2210 if (le32_to_cpu(desc->dwLength) > len)
2211 return -EINVAL;
2212
2213 ret = __ffs_do_os_desc_header(&type, desc);
2214 if (unlikely(ret < 0)) {
2215 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2216 num, ret);
2217 return ret;
2218 }
2219 /*
2220 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2221 */
2222 feature_count = le16_to_cpu(desc->wCount);
2223 if (type == FFS_OS_DESC_EXT_COMPAT &&
2224 (feature_count > 255 || desc->Reserved))
2225 return -EINVAL;
2226 len -= ret;
2227 data += ret;
2228
2229 /*
2230 * Process all function/property descriptors
2231 * of this Feature Descriptor
2232 */
2233 ret = ffs_do_single_os_desc(data, len, type,
2234 feature_count, entity, priv, desc);
2235 if (unlikely(ret < 0)) {
2236 pr_debug("%s returns %d\n", __func__, ret);
2237 return ret;
2238 }
2239
2240 len -= ret;
2241 data += ret;
2242 }
2243 return _len - len;
2244 }
2245
2246 /**
2247 * Validate contents of the buffer from userspace related to OS descriptors.
2248 */
2249 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2250 struct usb_os_desc_header *h, void *data,
2251 unsigned len, void *priv)
2252 {
2253 struct ffs_data *ffs = priv;
2254 u8 length;
2255
2256 ENTER();
2257
2258 switch (type) {
2259 case FFS_OS_DESC_EXT_COMPAT: {
2260 struct usb_ext_compat_desc *d = data;
2261 int i;
2262
2263 if (len < sizeof(*d) ||
2264 d->bFirstInterfaceNumber >= ffs->interfaces_count)
2265 return -EINVAL;
2266 if (d->Reserved1 != 1) {
2267 /*
2268 * According to the spec, Reserved1 must be set to 1
2269 * but older kernels incorrectly rejected non-zero
2270 * values. We fix it here to avoid returning EINVAL
2271 * in response to values we used to accept.
2272 */
2273 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n");
2274 d->Reserved1 = 1;
2275 }
2276 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2277 if (d->Reserved2[i])
2278 return -EINVAL;
2279
2280 length = sizeof(struct usb_ext_compat_desc);
2281 }
2282 break;
2283 case FFS_OS_DESC_EXT_PROP: {
2284 struct usb_ext_prop_desc *d = data;
2285 u32 type, pdl;
2286 u16 pnl;
2287
2288 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2289 return -EINVAL;
2290 length = le32_to_cpu(d->dwSize);
2291 if (len < length)
2292 return -EINVAL;
2293 type = le32_to_cpu(d->dwPropertyDataType);
2294 if (type < USB_EXT_PROP_UNICODE ||
2295 type > USB_EXT_PROP_UNICODE_MULTI) {
2296 pr_vdebug("unsupported os descriptor property type: %d",
2297 type);
2298 return -EINVAL;
2299 }
2300 pnl = le16_to_cpu(d->wPropertyNameLength);
2301 if (length < 14 + pnl) {
2302 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2303 length, pnl, type);
2304 return -EINVAL;
2305 }
2306 pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl));
2307 if (length != 14 + pnl + pdl) {
2308 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2309 length, pnl, pdl, type);
2310 return -EINVAL;
2311 }
2312 ++ffs->ms_os_descs_ext_prop_count;
2313 /* property name reported to the host as "WCHAR"s */
2314 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2315 ffs->ms_os_descs_ext_prop_data_len += pdl;
2316 }
2317 break;
2318 default:
2319 pr_vdebug("unknown descriptor: %d\n", type);
2320 return -EINVAL;
2321 }
2322 return length;
2323 }
2324
2325 static int __ffs_data_got_descs(struct ffs_data *ffs,
2326 char *const _data, size_t len)
2327 {
2328 char *data = _data, *raw_descs;
2329 unsigned os_descs_count = 0, counts[3], flags;
2330 int ret = -EINVAL, i;
2331 struct ffs_desc_helper helper;
2332
2333 ENTER();
2334
2335 if (get_unaligned_le32(data + 4) != len)
2336 goto error;
2337
2338 switch (get_unaligned_le32(data)) {
2339 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2340 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2341 data += 8;
2342 len -= 8;
2343 break;
2344 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2345 flags = get_unaligned_le32(data + 8);
2346 ffs->user_flags = flags;
2347 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2348 FUNCTIONFS_HAS_HS_DESC |
2349 FUNCTIONFS_HAS_SS_DESC |
2350 FUNCTIONFS_HAS_MS_OS_DESC |
2351 FUNCTIONFS_VIRTUAL_ADDR |
2352 FUNCTIONFS_EVENTFD |
2353 FUNCTIONFS_ALL_CTRL_RECIP |
2354 FUNCTIONFS_CONFIG0_SETUP)) {
2355 ret = -ENOSYS;
2356 goto error;
2357 }
2358 data += 12;
2359 len -= 12;
2360 break;
2361 default:
2362 goto error;
2363 }
2364
2365 if (flags & FUNCTIONFS_EVENTFD) {
2366 if (len < 4)
2367 goto error;
2368 ffs->ffs_eventfd =
2369 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2370 if (IS_ERR(ffs->ffs_eventfd)) {
2371 ret = PTR_ERR(ffs->ffs_eventfd);
2372 ffs->ffs_eventfd = NULL;
2373 goto error;
2374 }
2375 data += 4;
2376 len -= 4;
2377 }
2378
2379 /* Read fs_count, hs_count and ss_count (if present) */
2380 for (i = 0; i < 3; ++i) {
2381 if (!(flags & (1 << i))) {
2382 counts[i] = 0;
2383 } else if (len < 4) {
2384 goto error;
2385 } else {
2386 counts[i] = get_unaligned_le32(data);
2387 data += 4;
2388 len -= 4;
2389 }
2390 }
2391 if (flags & (1 << i)) {
2392 if (len < 4) {
2393 goto error;
2394 }
2395 os_descs_count = get_unaligned_le32(data);
2396 data += 4;
2397 len -= 4;
2398 };
2399
2400 /* Read descriptors */
2401 raw_descs = data;
2402 helper.ffs = ffs;
2403 for (i = 0; i < 3; ++i) {
2404 if (!counts[i])
2405 continue;
2406 helper.interfaces_count = 0;
2407 helper.eps_count = 0;
2408 ret = ffs_do_descs(counts[i], data, len,
2409 __ffs_data_do_entity, &helper);
2410 if (ret < 0)
2411 goto error;
2412 if (!ffs->eps_count && !ffs->interfaces_count) {
2413 ffs->eps_count = helper.eps_count;
2414 ffs->interfaces_count = helper.interfaces_count;
2415 } else {
2416 if (ffs->eps_count != helper.eps_count) {
2417 ret = -EINVAL;
2418 goto error;
2419 }
2420 if (ffs->interfaces_count != helper.interfaces_count) {
2421 ret = -EINVAL;
2422 goto error;
2423 }
2424 }
2425 data += ret;
2426 len -= ret;
2427 }
2428 if (os_descs_count) {
2429 ret = ffs_do_os_descs(os_descs_count, data, len,
2430 __ffs_data_do_os_desc, ffs);
2431 if (ret < 0)
2432 goto error;
2433 data += ret;
2434 len -= ret;
2435 }
2436
2437 if (raw_descs == data || len) {
2438 ret = -EINVAL;
2439 goto error;
2440 }
2441
2442 ffs->raw_descs_data = _data;
2443 ffs->raw_descs = raw_descs;
2444 ffs->raw_descs_length = data - raw_descs;
2445 ffs->fs_descs_count = counts[0];
2446 ffs->hs_descs_count = counts[1];
2447 ffs->ss_descs_count = counts[2];
2448 ffs->ms_os_descs_count = os_descs_count;
2449
2450 return 0;
2451
2452 error:
2453 kfree(_data);
2454 return ret;
2455 }
2456
2457 static int __ffs_data_got_strings(struct ffs_data *ffs,
2458 char *const _data, size_t len)
2459 {
2460 u32 str_count, needed_count, lang_count;
2461 struct usb_gadget_strings **stringtabs, *t;
2462 const char *data = _data;
2463 struct usb_string *s;
2464
2465 ENTER();
2466
2467 if (unlikely(len < 16 ||
2468 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2469 get_unaligned_le32(data + 4) != len))
2470 goto error;
2471 str_count = get_unaligned_le32(data + 8);
2472 lang_count = get_unaligned_le32(data + 12);
2473
2474 /* if one is zero the other must be zero */
2475 if (unlikely(!str_count != !lang_count))
2476 goto error;
2477
2478 /* Do we have at least as many strings as descriptors need? */
2479 needed_count = ffs->strings_count;
2480 if (unlikely(str_count < needed_count))
2481 goto error;
2482
2483 /*
2484 * If we don't need any strings just return and free all
2485 * memory.
2486 */
2487 if (!needed_count) {
2488 kfree(_data);
2489 return 0;
2490 }
2491
2492 /* Allocate everything in one chunk so there's less maintenance. */
2493 {
2494 unsigned i = 0;
2495 vla_group(d);
2496 vla_item(d, struct usb_gadget_strings *, stringtabs,
2497 lang_count + 1);
2498 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2499 vla_item(d, struct usb_string, strings,
2500 lang_count*(needed_count+1));
2501
2502 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2503
2504 if (unlikely(!vlabuf)) {
2505 kfree(_data);
2506 return -ENOMEM;
2507 }
2508
2509 /* Initialize the VLA pointers */
2510 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2511 t = vla_ptr(vlabuf, d, stringtab);
2512 i = lang_count;
2513 do {
2514 *stringtabs++ = t++;
2515 } while (--i);
2516 *stringtabs = NULL;
2517
2518 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2519 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2520 t = vla_ptr(vlabuf, d, stringtab);
2521 s = vla_ptr(vlabuf, d, strings);
2522 }
2523
2524 /* For each language */
2525 data += 16;
2526 len -= 16;
2527
2528 do { /* lang_count > 0 so we can use do-while */
2529 unsigned needed = needed_count;
2530
2531 if (unlikely(len < 3))
2532 goto error_free;
2533 t->language = get_unaligned_le16(data);
2534 t->strings = s;
2535 ++t;
2536
2537 data += 2;
2538 len -= 2;
2539
2540 /* For each string */
2541 do { /* str_count > 0 so we can use do-while */
2542 size_t length = strnlen(data, len);
2543
2544 if (unlikely(length == len))
2545 goto error_free;
2546
2547 /*
2548 * User may provide more strings then we need,
2549 * if that's the case we simply ignore the
2550 * rest
2551 */
2552 if (likely(needed)) {
2553 /*
2554 * s->id will be set while adding
2555 * function to configuration so for
2556 * now just leave garbage here.
2557 */
2558 s->s = data;
2559 --needed;
2560 ++s;
2561 }
2562
2563 data += length + 1;
2564 len -= length + 1;
2565 } while (--str_count);
2566
2567 s->id = 0; /* terminator */
2568 s->s = NULL;
2569 ++s;
2570
2571 } while (--lang_count);
2572
2573 /* Some garbage left? */
2574 if (unlikely(len))
2575 goto error_free;
2576
2577 /* Done! */
2578 ffs->stringtabs = stringtabs;
2579 ffs->raw_strings = _data;
2580
2581 return 0;
2582
2583 error_free:
2584 kfree(stringtabs);
2585 error:
2586 kfree(_data);
2587 return -EINVAL;
2588 }
2589
2590
2591 /* Events handling and management *******************************************/
2592
2593 static void __ffs_event_add(struct ffs_data *ffs,
2594 enum usb_functionfs_event_type type)
2595 {
2596 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2597 int neg = 0;
2598
2599 /*
2600 * Abort any unhandled setup
2601 *
2602 * We do not need to worry about some cmpxchg() changing value
2603 * of ffs->setup_state without holding the lock because when
2604 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2605 * the source does nothing.
2606 */
2607 if (ffs->setup_state == FFS_SETUP_PENDING)
2608 ffs->setup_state = FFS_SETUP_CANCELLED;
2609
2610 /*
2611 * Logic of this function guarantees that there are at most four pending
2612 * evens on ffs->ev.types queue. This is important because the queue
2613 * has space for four elements only and __ffs_ep0_read_events function
2614 * depends on that limit as well. If more event types are added, those
2615 * limits have to be revisited or guaranteed to still hold.
2616 */
2617 switch (type) {
2618 case FUNCTIONFS_RESUME:
2619 rem_type2 = FUNCTIONFS_SUSPEND;
2620 /* FALL THROUGH */
2621 case FUNCTIONFS_SUSPEND:
2622 case FUNCTIONFS_SETUP:
2623 rem_type1 = type;
2624 /* Discard all similar events */
2625 break;
2626
2627 case FUNCTIONFS_BIND:
2628 case FUNCTIONFS_UNBIND:
2629 case FUNCTIONFS_DISABLE:
2630 case FUNCTIONFS_ENABLE:
2631 /* Discard everything other then power management. */
2632 rem_type1 = FUNCTIONFS_SUSPEND;
2633 rem_type2 = FUNCTIONFS_RESUME;
2634 neg = 1;
2635 break;
2636
2637 default:
2638 WARN(1, "%d: unknown event, this should not happen\n", type);
2639 return;
2640 }
2641
2642 {
2643 u8 *ev = ffs->ev.types, *out = ev;
2644 unsigned n = ffs->ev.count;
2645 for (; n; --n, ++ev)
2646 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2647 *out++ = *ev;
2648 else
2649 pr_vdebug("purging event %d\n", *ev);
2650 ffs->ev.count = out - ffs->ev.types;
2651 }
2652
2653 pr_vdebug("adding event %d\n", type);
2654 ffs->ev.types[ffs->ev.count++] = type;
2655 wake_up_locked(&ffs->ev.waitq);
2656 if (ffs->ffs_eventfd)
2657 eventfd_signal(ffs->ffs_eventfd, 1);
2658 }
2659
2660 static void ffs_event_add(struct ffs_data *ffs,
2661 enum usb_functionfs_event_type type)
2662 {
2663 unsigned long flags;
2664 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2665 __ffs_event_add(ffs, type);
2666 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2667 }
2668
2669 /* Bind/unbind USB function hooks *******************************************/
2670
2671 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2672 {
2673 int i;
2674
2675 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2676 if (ffs->eps_addrmap[i] == endpoint_address)
2677 return i;
2678 return -ENOENT;
2679 }
2680
2681 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2682 struct usb_descriptor_header *desc,
2683 void *priv)
2684 {
2685 struct usb_endpoint_descriptor *ds = (void *)desc;
2686 struct ffs_function *func = priv;
2687 struct ffs_ep *ffs_ep;
2688 unsigned ep_desc_id;
2689 int idx;
2690 static const char *speed_names[] = { "full", "high", "super" };
2691
2692 if (type != FFS_DESCRIPTOR)
2693 return 0;
2694
2695 /*
2696 * If ss_descriptors is not NULL, we are reading super speed
2697 * descriptors; if hs_descriptors is not NULL, we are reading high
2698 * speed descriptors; otherwise, we are reading full speed
2699 * descriptors.
2700 */
2701 if (func->function.ss_descriptors) {
2702 ep_desc_id = 2;
2703 func->function.ss_descriptors[(long)valuep] = desc;
2704 } else if (func->function.hs_descriptors) {
2705 ep_desc_id = 1;
2706 func->function.hs_descriptors[(long)valuep] = desc;
2707 } else {
2708 ep_desc_id = 0;
2709 func->function.fs_descriptors[(long)valuep] = desc;
2710 }
2711
2712 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2713 return 0;
2714
2715 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2716 if (idx < 0)
2717 return idx;
2718
2719 ffs_ep = func->eps + idx;
2720
2721 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2722 pr_err("two %sspeed descriptors for EP %d\n",
2723 speed_names[ep_desc_id],
2724 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2725 return -EINVAL;
2726 }
2727 ffs_ep->descs[ep_desc_id] = ds;
2728
2729 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2730 if (ffs_ep->ep) {
2731 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2732 if (!ds->wMaxPacketSize)
2733 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2734 } else {
2735 struct usb_request *req;
2736 struct usb_ep *ep;
2737 u8 bEndpointAddress;
2738
2739 /*
2740 * We back up bEndpointAddress because autoconfig overwrites
2741 * it with physical endpoint address.
2742 */
2743 bEndpointAddress = ds->bEndpointAddress;
2744 pr_vdebug("autoconfig\n");
2745 ep = usb_ep_autoconfig(func->gadget, ds);
2746 if (unlikely(!ep))
2747 return -ENOTSUPP;
2748 ep->driver_data = func->eps + idx;
2749
2750 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2751 if (unlikely(!req))
2752 return -ENOMEM;
2753
2754 ffs_ep->ep = ep;
2755 ffs_ep->req = req;
2756 func->eps_revmap[ds->bEndpointAddress &
2757 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2758 /*
2759 * If we use virtual address mapping, we restore
2760 * original bEndpointAddress value.
2761 */
2762 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2763 ds->bEndpointAddress = bEndpointAddress;
2764 }
2765 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2766
2767 return 0;
2768 }
2769
2770 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2771 struct usb_descriptor_header *desc,
2772 void *priv)
2773 {
2774 struct ffs_function *func = priv;
2775 unsigned idx;
2776 u8 newValue;
2777
2778 switch (type) {
2779 default:
2780 case FFS_DESCRIPTOR:
2781 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2782 return 0;
2783
2784 case FFS_INTERFACE:
2785 idx = *valuep;
2786 if (func->interfaces_nums[idx] < 0) {
2787 int id = usb_interface_id(func->conf, &func->function);
2788 if (unlikely(id < 0))
2789 return id;
2790 func->interfaces_nums[idx] = id;
2791 }
2792 newValue = func->interfaces_nums[idx];
2793 break;
2794
2795 case FFS_STRING:
2796 /* String' IDs are allocated when fsf_data is bound to cdev */
2797 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2798 break;
2799
2800 case FFS_ENDPOINT:
2801 /*
2802 * USB_DT_ENDPOINT are handled in
2803 * __ffs_func_bind_do_descs().
2804 */
2805 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2806 return 0;
2807
2808 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2809 if (unlikely(!func->eps[idx].ep))
2810 return -EINVAL;
2811
2812 {
2813 struct usb_endpoint_descriptor **descs;
2814 descs = func->eps[idx].descs;
2815 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2816 }
2817 break;
2818 }
2819
2820 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2821 *valuep = newValue;
2822 return 0;
2823 }
2824
2825 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2826 struct usb_os_desc_header *h, void *data,
2827 unsigned len, void *priv)
2828 {
2829 struct ffs_function *func = priv;
2830 u8 length = 0;
2831
2832 switch (type) {
2833 case FFS_OS_DESC_EXT_COMPAT: {
2834 struct usb_ext_compat_desc *desc = data;
2835 struct usb_os_desc_table *t;
2836
2837 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2838 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2839 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2840 ARRAY_SIZE(desc->CompatibleID) +
2841 ARRAY_SIZE(desc->SubCompatibleID));
2842 length = sizeof(*desc);
2843 }
2844 break;
2845 case FFS_OS_DESC_EXT_PROP: {
2846 struct usb_ext_prop_desc *desc = data;
2847 struct usb_os_desc_table *t;
2848 struct usb_os_desc_ext_prop *ext_prop;
2849 char *ext_prop_name;
2850 char *ext_prop_data;
2851
2852 t = &func->function.os_desc_table[h->interface];
2853 t->if_id = func->interfaces_nums[h->interface];
2854
2855 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2856 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2857
2858 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2859 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2860 ext_prop->data_len = le32_to_cpu(*(__le32 *)
2861 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2862 length = ext_prop->name_len + ext_prop->data_len + 14;
2863
2864 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2865 func->ffs->ms_os_descs_ext_prop_name_avail +=
2866 ext_prop->name_len;
2867
2868 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2869 func->ffs->ms_os_descs_ext_prop_data_avail +=
2870 ext_prop->data_len;
2871 memcpy(ext_prop_data,
2872 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2873 ext_prop->data_len);
2874 /* unicode data reported to the host as "WCHAR"s */
2875 switch (ext_prop->type) {
2876 case USB_EXT_PROP_UNICODE:
2877 case USB_EXT_PROP_UNICODE_ENV:
2878 case USB_EXT_PROP_UNICODE_LINK:
2879 case USB_EXT_PROP_UNICODE_MULTI:
2880 ext_prop->data_len *= 2;
2881 break;
2882 }
2883 ext_prop->data = ext_prop_data;
2884
2885 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2886 ext_prop->name_len);
2887 /* property name reported to the host as "WCHAR"s */
2888 ext_prop->name_len *= 2;
2889 ext_prop->name = ext_prop_name;
2890
2891 t->os_desc->ext_prop_len +=
2892 ext_prop->name_len + ext_prop->data_len + 14;
2893 ++t->os_desc->ext_prop_count;
2894 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2895 }
2896 break;
2897 default:
2898 pr_vdebug("unknown descriptor: %d\n", type);
2899 }
2900
2901 return length;
2902 }
2903
2904 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2905 struct usb_configuration *c)
2906 {
2907 struct ffs_function *func = ffs_func_from_usb(f);
2908 struct f_fs_opts *ffs_opts =
2909 container_of(f->fi, struct f_fs_opts, func_inst);
2910 int ret;
2911
2912 ENTER();
2913
2914 /*
2915 * Legacy gadget triggers binding in functionfs_ready_callback,
2916 * which already uses locking; taking the same lock here would
2917 * cause a deadlock.
2918 *
2919 * Configfs-enabled gadgets however do need ffs_dev_lock.
2920 */
2921 if (!ffs_opts->no_configfs)
2922 ffs_dev_lock();
2923 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2924 func->ffs = ffs_opts->dev->ffs_data;
2925 if (!ffs_opts->no_configfs)
2926 ffs_dev_unlock();
2927 if (ret)
2928 return ERR_PTR(ret);
2929
2930 func->conf = c;
2931 func->gadget = c->cdev->gadget;
2932
2933 /*
2934 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2935 * configurations are bound in sequence with list_for_each_entry,
2936 * in each configuration its functions are bound in sequence
2937 * with list_for_each_entry, so we assume no race condition
2938 * with regard to ffs_opts->bound access
2939 */
2940 if (!ffs_opts->refcnt) {
2941 ret = functionfs_bind(func->ffs, c->cdev);
2942 if (ret)
2943 return ERR_PTR(ret);
2944 }
2945 ffs_opts->refcnt++;
2946 func->function.strings = func->ffs->stringtabs;
2947
2948 return ffs_opts;
2949 }
2950
2951 static int _ffs_func_bind(struct usb_configuration *c,
2952 struct usb_function *f)
2953 {
2954 struct ffs_function *func = ffs_func_from_usb(f);
2955 struct ffs_data *ffs = func->ffs;
2956
2957 const int full = !!func->ffs->fs_descs_count;
2958 const int high = !!func->ffs->hs_descs_count;
2959 const int super = !!func->ffs->ss_descs_count;
2960
2961 int fs_len, hs_len, ss_len, ret, i;
2962 struct ffs_ep *eps_ptr;
2963
2964 /* Make it a single chunk, less management later on */
2965 vla_group(d);
2966 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2967 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2968 full ? ffs->fs_descs_count + 1 : 0);
2969 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2970 high ? ffs->hs_descs_count + 1 : 0);
2971 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2972 super ? ffs->ss_descs_count + 1 : 0);
2973 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2974 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2975 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2976 vla_item_with_sz(d, char[16], ext_compat,
2977 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2978 vla_item_with_sz(d, struct usb_os_desc, os_desc,
2979 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2980 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2981 ffs->ms_os_descs_ext_prop_count);
2982 vla_item_with_sz(d, char, ext_prop_name,
2983 ffs->ms_os_descs_ext_prop_name_len);
2984 vla_item_with_sz(d, char, ext_prop_data,
2985 ffs->ms_os_descs_ext_prop_data_len);
2986 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2987 char *vlabuf;
2988
2989 ENTER();
2990
2991 /* Has descriptors only for speeds gadget does not support */
2992 if (unlikely(!(full | high | super)))
2993 return -ENOTSUPP;
2994
2995 /* Allocate a single chunk, less management later on */
2996 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2997 if (unlikely(!vlabuf))
2998 return -ENOMEM;
2999
3000 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
3001 ffs->ms_os_descs_ext_prop_name_avail =
3002 vla_ptr(vlabuf, d, ext_prop_name);
3003 ffs->ms_os_descs_ext_prop_data_avail =
3004 vla_ptr(vlabuf, d, ext_prop_data);
3005
3006 /* Copy descriptors */
3007 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
3008 ffs->raw_descs_length);
3009
3010 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
3011 eps_ptr = vla_ptr(vlabuf, d, eps);
3012 for (i = 0; i < ffs->eps_count; i++)
3013 eps_ptr[i].num = -1;
3014
3015 /* Save pointers
3016 * d_eps == vlabuf, func->eps used to kfree vlabuf later
3017 */
3018 func->eps = vla_ptr(vlabuf, d, eps);
3019 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
3020
3021 /*
3022 * Go through all the endpoint descriptors and allocate
3023 * endpoints first, so that later we can rewrite the endpoint
3024 * numbers without worrying that it may be described later on.
3025 */
3026 if (likely(full)) {
3027 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
3028 fs_len = ffs_do_descs(ffs->fs_descs_count,
3029 vla_ptr(vlabuf, d, raw_descs),
3030 d_raw_descs__sz,
3031 __ffs_func_bind_do_descs, func);
3032 if (unlikely(fs_len < 0)) {
3033 ret = fs_len;
3034 goto error;
3035 }
3036 } else {
3037 fs_len = 0;
3038 }
3039
3040 if (likely(high)) {
3041 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
3042 hs_len = ffs_do_descs(ffs->hs_descs_count,
3043 vla_ptr(vlabuf, d, raw_descs) + fs_len,
3044 d_raw_descs__sz - fs_len,
3045 __ffs_func_bind_do_descs, func);
3046 if (unlikely(hs_len < 0)) {
3047 ret = hs_len;
3048 goto error;
3049 }
3050 } else {
3051 hs_len = 0;
3052 }
3053
3054 if (likely(super)) {
3055 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
3056 ss_len = ffs_do_descs(ffs->ss_descs_count,
3057 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
3058 d_raw_descs__sz - fs_len - hs_len,
3059 __ffs_func_bind_do_descs, func);
3060 if (unlikely(ss_len < 0)) {
3061 ret = ss_len;
3062 goto error;
3063 }
3064 } else {
3065 ss_len = 0;
3066 }
3067
3068 /*
3069 * Now handle interface numbers allocation and interface and
3070 * endpoint numbers rewriting. We can do that in one go
3071 * now.
3072 */
3073 ret = ffs_do_descs(ffs->fs_descs_count +
3074 (high ? ffs->hs_descs_count : 0) +
3075 (super ? ffs->ss_descs_count : 0),
3076 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
3077 __ffs_func_bind_do_nums, func);
3078 if (unlikely(ret < 0))
3079 goto error;
3080
3081 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
3082 if (c->cdev->use_os_string) {
3083 for (i = 0; i < ffs->interfaces_count; ++i) {
3084 struct usb_os_desc *desc;
3085
3086 desc = func->function.os_desc_table[i].os_desc =
3087 vla_ptr(vlabuf, d, os_desc) +
3088 i * sizeof(struct usb_os_desc);
3089 desc->ext_compat_id =
3090 vla_ptr(vlabuf, d, ext_compat) + i * 16;
3091 INIT_LIST_HEAD(&desc->ext_prop);
3092 }
3093 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
3094 vla_ptr(vlabuf, d, raw_descs) +
3095 fs_len + hs_len + ss_len,
3096 d_raw_descs__sz - fs_len - hs_len -
3097 ss_len,
3098 __ffs_func_bind_do_os_desc, func);
3099 if (unlikely(ret < 0))
3100 goto error;
3101 }
3102 func->function.os_desc_n =
3103 c->cdev->use_os_string ? ffs->interfaces_count : 0;
3104
3105 /* And we're done */
3106 ffs_event_add(ffs, FUNCTIONFS_BIND);
3107 return 0;
3108
3109 error:
3110 /* XXX Do we need to release all claimed endpoints here? */
3111 return ret;
3112 }
3113
3114 static int ffs_func_bind(struct usb_configuration *c,
3115 struct usb_function *f)
3116 {
3117 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
3118 struct ffs_function *func = ffs_func_from_usb(f);
3119 int ret;
3120
3121 if (IS_ERR(ffs_opts))
3122 return PTR_ERR(ffs_opts);
3123
3124 ret = _ffs_func_bind(c, f);
3125 if (ret && !--ffs_opts->refcnt)
3126 functionfs_unbind(func->ffs);
3127
3128 return ret;
3129 }
3130
3131
3132 /* Other USB function hooks *************************************************/
3133
3134 static void ffs_reset_work(struct work_struct *work)
3135 {
3136 struct ffs_data *ffs = container_of(work,
3137 struct ffs_data, reset_work);
3138 ffs_data_reset(ffs);
3139 }
3140
3141 static int ffs_func_set_alt(struct usb_function *f,
3142 unsigned interface, unsigned alt)
3143 {
3144 struct ffs_function *func = ffs_func_from_usb(f);
3145 struct ffs_data *ffs = func->ffs;
3146 int ret = 0, intf;
3147
3148 if (alt != (unsigned)-1) {
3149 intf = ffs_func_revmap_intf(func, interface);
3150 if (unlikely(intf < 0))
3151 return intf;
3152 }
3153
3154 if (ffs->func)
3155 ffs_func_eps_disable(ffs->func);
3156
3157 if (ffs->state == FFS_DEACTIVATED) {
3158 ffs->state = FFS_CLOSING;
3159 INIT_WORK(&ffs->reset_work, ffs_reset_work);
3160 schedule_work(&ffs->reset_work);
3161 return -ENODEV;
3162 }
3163
3164 if (ffs->state != FFS_ACTIVE)
3165 return -ENODEV;
3166
3167 if (alt == (unsigned)-1) {
3168 ffs->func = NULL;
3169 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
3170 return 0;
3171 }
3172
3173 ffs->func = func;
3174 ret = ffs_func_eps_enable(func);
3175 if (likely(ret >= 0))
3176 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
3177 return ret;
3178 }
3179
3180 static void ffs_func_disable(struct usb_function *f)
3181 {
3182 ffs_func_set_alt(f, 0, (unsigned)-1);
3183 }
3184
3185 static int ffs_func_setup(struct usb_function *f,
3186 const struct usb_ctrlrequest *creq)
3187 {
3188 struct ffs_function *func = ffs_func_from_usb(f);
3189 struct ffs_data *ffs = func->ffs;
3190 unsigned long flags;
3191 int ret;
3192
3193 ENTER();
3194
3195 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
3196 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
3197 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
3198 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
3199 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
3200
3201 /*
3202 * Most requests directed to interface go through here
3203 * (notable exceptions are set/get interface) so we need to
3204 * handle them. All other either handled by composite or
3205 * passed to usb_configuration->setup() (if one is set). No
3206 * matter, we will handle requests directed to endpoint here
3207 * as well (as it's straightforward). Other request recipient
3208 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
3209 * is being used.
3210 */
3211 if (ffs->state != FFS_ACTIVE)
3212 return -ENODEV;
3213
3214 switch (creq->bRequestType & USB_RECIP_MASK) {
3215 case USB_RECIP_INTERFACE:
3216 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3217 if (unlikely(ret < 0))
3218 return ret;
3219 break;
3220
3221 case USB_RECIP_ENDPOINT:
3222 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3223 if (unlikely(ret < 0))
3224 return ret;
3225 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3226 ret = func->ffs->eps_addrmap[ret];
3227 break;
3228
3229 default:
3230 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
3231 ret = le16_to_cpu(creq->wIndex);
3232 else
3233 return -EOPNOTSUPP;
3234 }
3235
3236 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3237 ffs->ev.setup = *creq;
3238 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3239 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3240 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3241
3242 return 0;
3243 }
3244
3245 static bool ffs_func_req_match(struct usb_function *f,
3246 const struct usb_ctrlrequest *creq,
3247 bool config0)
3248 {
3249 struct ffs_function *func = ffs_func_from_usb(f);
3250
3251 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP))
3252 return false;
3253
3254 switch (creq->bRequestType & USB_RECIP_MASK) {
3255 case USB_RECIP_INTERFACE:
3256 return (ffs_func_revmap_intf(func,
3257 le16_to_cpu(creq->wIndex)) >= 0);
3258 case USB_RECIP_ENDPOINT:
3259 return (ffs_func_revmap_ep(func,
3260 le16_to_cpu(creq->wIndex)) >= 0);
3261 default:
3262 return (bool) (func->ffs->user_flags &
3263 FUNCTIONFS_ALL_CTRL_RECIP);
3264 }
3265 }
3266
3267 static void ffs_func_suspend(struct usb_function *f)
3268 {
3269 ENTER();
3270 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3271 }
3272
3273 static void ffs_func_resume(struct usb_function *f)
3274 {
3275 ENTER();
3276 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3277 }
3278
3279
3280 /* Endpoint and interface numbers reverse mapping ***************************/
3281
3282 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3283 {
3284 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3285 return num ? num : -EDOM;
3286 }
3287
3288 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3289 {
3290 short *nums = func->interfaces_nums;
3291 unsigned count = func->ffs->interfaces_count;
3292
3293 for (; count; --count, ++nums) {
3294 if (*nums >= 0 && *nums == intf)
3295 return nums - func->interfaces_nums;
3296 }
3297
3298 return -EDOM;
3299 }
3300
3301
3302 /* Devices management *******************************************************/
3303
3304 static LIST_HEAD(ffs_devices);
3305
3306 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3307 {
3308 struct ffs_dev *dev;
3309
3310 if (!name)
3311 return NULL;
3312
3313 list_for_each_entry(dev, &ffs_devices, entry) {
3314 if (strcmp(dev->name, name) == 0)
3315 return dev;
3316 }
3317
3318 return NULL;
3319 }
3320
3321 /*
3322 * ffs_lock must be taken by the caller of this function
3323 */
3324 static struct ffs_dev *_ffs_get_single_dev(void)
3325 {
3326 struct ffs_dev *dev;
3327
3328 if (list_is_singular(&ffs_devices)) {
3329 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3330 if (dev->single)
3331 return dev;
3332 }
3333
3334 return NULL;
3335 }
3336
3337 /*
3338 * ffs_lock must be taken by the caller of this function
3339 */
3340 static struct ffs_dev *_ffs_find_dev(const char *name)
3341 {
3342 struct ffs_dev *dev;
3343
3344 dev = _ffs_get_single_dev();
3345 if (dev)
3346 return dev;
3347
3348 return _ffs_do_find_dev(name);
3349 }
3350
3351 /* Configfs support *********************************************************/
3352
3353 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3354 {
3355 return container_of(to_config_group(item), struct f_fs_opts,
3356 func_inst.group);
3357 }
3358
3359 static void ffs_attr_release(struct config_item *item)
3360 {
3361 struct f_fs_opts *opts = to_ffs_opts(item);
3362
3363 usb_put_function_instance(&opts->func_inst);
3364 }
3365
3366 static struct configfs_item_operations ffs_item_ops = {
3367 .release = ffs_attr_release,
3368 };
3369
3370 static const struct config_item_type ffs_func_type = {
3371 .ct_item_ops = &ffs_item_ops,
3372 .ct_owner = THIS_MODULE,
3373 };
3374
3375
3376 /* Function registration interface ******************************************/
3377
3378 static void ffs_free_inst(struct usb_function_instance *f)
3379 {
3380 struct f_fs_opts *opts;
3381
3382 opts = to_f_fs_opts(f);
3383 ffs_dev_lock();
3384 _ffs_free_dev(opts->dev);
3385 ffs_dev_unlock();
3386 kfree(opts);
3387 }
3388
3389 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3390 {
3391 if (strlen(name) >= FIELD_SIZEOF(struct ffs_dev, name))
3392 return -ENAMETOOLONG;
3393 return ffs_name_dev(to_f_fs_opts(fi)->dev, name);
3394 }
3395
3396 static struct usb_function_instance *ffs_alloc_inst(void)
3397 {
3398 struct f_fs_opts *opts;
3399 struct ffs_dev *dev;
3400
3401 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3402 if (!opts)
3403 return ERR_PTR(-ENOMEM);
3404
3405 opts->func_inst.set_inst_name = ffs_set_inst_name;
3406 opts->func_inst.free_func_inst = ffs_free_inst;
3407 ffs_dev_lock();
3408 dev = _ffs_alloc_dev();
3409 ffs_dev_unlock();
3410 if (IS_ERR(dev)) {
3411 kfree(opts);
3412 return ERR_CAST(dev);
3413 }
3414 opts->dev = dev;
3415 dev->opts = opts;
3416
3417 config_group_init_type_name(&opts->func_inst.group, "",
3418 &ffs_func_type);
3419 return &opts->func_inst;
3420 }
3421
3422 static void ffs_free(struct usb_function *f)
3423 {
3424 kfree(ffs_func_from_usb(f));
3425 }
3426
3427 static void ffs_func_unbind(struct usb_configuration *c,
3428 struct usb_function *f)
3429 {
3430 struct ffs_function *func = ffs_func_from_usb(f);
3431 struct ffs_data *ffs = func->ffs;
3432 struct f_fs_opts *opts =
3433 container_of(f->fi, struct f_fs_opts, func_inst);
3434 struct ffs_ep *ep = func->eps;
3435 unsigned count = ffs->eps_count;
3436 unsigned long flags;
3437
3438 ENTER();
3439 if (ffs->func == func) {
3440 ffs_func_eps_disable(func);
3441 ffs->func = NULL;
3442 }
3443
3444 if (!--opts->refcnt)
3445 functionfs_unbind(ffs);
3446
3447 /* cleanup after autoconfig */
3448 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3449 while (count--) {
3450 if (ep->ep && ep->req)
3451 usb_ep_free_request(ep->ep, ep->req);
3452 ep->req = NULL;
3453 ++ep;
3454 }
3455 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3456 kfree(func->eps);
3457 func->eps = NULL;
3458 /*
3459 * eps, descriptors and interfaces_nums are allocated in the
3460 * same chunk so only one free is required.
3461 */
3462 func->function.fs_descriptors = NULL;
3463 func->function.hs_descriptors = NULL;
3464 func->function.ss_descriptors = NULL;
3465 func->interfaces_nums = NULL;
3466
3467 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3468 }
3469
3470 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3471 {
3472 struct ffs_function *func;
3473
3474 ENTER();
3475
3476 func = kzalloc(sizeof(*func), GFP_KERNEL);
3477 if (unlikely(!func))
3478 return ERR_PTR(-ENOMEM);
3479
3480 func->function.name = "Function FS Gadget";
3481
3482 func->function.bind = ffs_func_bind;
3483 func->function.unbind = ffs_func_unbind;
3484 func->function.set_alt = ffs_func_set_alt;
3485 func->function.disable = ffs_func_disable;
3486 func->function.setup = ffs_func_setup;
3487 func->function.req_match = ffs_func_req_match;
3488 func->function.suspend = ffs_func_suspend;
3489 func->function.resume = ffs_func_resume;
3490 func->function.free_func = ffs_free;
3491
3492 return &func->function;
3493 }
3494
3495 /*
3496 * ffs_lock must be taken by the caller of this function
3497 */
3498 static struct ffs_dev *_ffs_alloc_dev(void)
3499 {
3500 struct ffs_dev *dev;
3501 int ret;
3502
3503 if (_ffs_get_single_dev())
3504 return ERR_PTR(-EBUSY);
3505
3506 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3507 if (!dev)
3508 return ERR_PTR(-ENOMEM);
3509
3510 if (list_empty(&ffs_devices)) {
3511 ret = functionfs_init();
3512 if (ret) {
3513 kfree(dev);
3514 return ERR_PTR(ret);
3515 }
3516 }
3517
3518 list_add(&dev->entry, &ffs_devices);
3519
3520 return dev;
3521 }
3522
3523 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3524 {
3525 struct ffs_dev *existing;
3526 int ret = 0;
3527
3528 ffs_dev_lock();
3529
3530 existing = _ffs_do_find_dev(name);
3531 if (!existing)
3532 strlcpy(dev->name, name, ARRAY_SIZE(dev->name));
3533 else if (existing != dev)
3534 ret = -EBUSY;
3535
3536 ffs_dev_unlock();
3537
3538 return ret;
3539 }
3540 EXPORT_SYMBOL_GPL(ffs_name_dev);
3541
3542 int ffs_single_dev(struct ffs_dev *dev)
3543 {
3544 int ret;
3545
3546 ret = 0;
3547 ffs_dev_lock();
3548
3549 if (!list_is_singular(&ffs_devices))
3550 ret = -EBUSY;
3551 else
3552 dev->single = true;
3553
3554 ffs_dev_unlock();
3555 return ret;
3556 }
3557 EXPORT_SYMBOL_GPL(ffs_single_dev);
3558
3559 /*
3560 * ffs_lock must be taken by the caller of this function
3561 */
3562 static void _ffs_free_dev(struct ffs_dev *dev)
3563 {
3564 list_del(&dev->entry);
3565
3566 /* Clear the private_data pointer to stop incorrect dev access */
3567 if (dev->ffs_data)
3568 dev->ffs_data->private_data = NULL;
3569
3570 kfree(dev);
3571 if (list_empty(&ffs_devices))
3572 functionfs_cleanup();
3573 }
3574
3575 static void *ffs_acquire_dev(const char *dev_name)
3576 {
3577 struct ffs_dev *ffs_dev;
3578
3579 ENTER();
3580 ffs_dev_lock();
3581
3582 ffs_dev = _ffs_find_dev(dev_name);
3583 if (!ffs_dev)
3584 ffs_dev = ERR_PTR(-ENOENT);
3585 else if (ffs_dev->mounted)
3586 ffs_dev = ERR_PTR(-EBUSY);
3587 else if (ffs_dev->ffs_acquire_dev_callback &&
3588 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3589 ffs_dev = ERR_PTR(-ENOENT);
3590 else
3591 ffs_dev->mounted = true;
3592
3593 ffs_dev_unlock();
3594 return ffs_dev;
3595 }
3596
3597 static void ffs_release_dev(struct ffs_data *ffs_data)
3598 {
3599 struct ffs_dev *ffs_dev;
3600
3601 ENTER();
3602 ffs_dev_lock();
3603
3604 ffs_dev = ffs_data->private_data;
3605 if (ffs_dev) {
3606 ffs_dev->mounted = false;
3607
3608 if (ffs_dev->ffs_release_dev_callback)
3609 ffs_dev->ffs_release_dev_callback(ffs_dev);
3610 }
3611
3612 ffs_dev_unlock();
3613 }
3614
3615 static int ffs_ready(struct ffs_data *ffs)
3616 {
3617 struct ffs_dev *ffs_obj;
3618 int ret = 0;
3619
3620 ENTER();
3621 ffs_dev_lock();
3622
3623 ffs_obj = ffs->private_data;
3624 if (!ffs_obj) {
3625 ret = -EINVAL;
3626 goto done;
3627 }
3628 if (WARN_ON(ffs_obj->desc_ready)) {
3629 ret = -EBUSY;
3630 goto done;
3631 }
3632
3633 ffs_obj->desc_ready = true;
3634 ffs_obj->ffs_data = ffs;
3635
3636 if (ffs_obj->ffs_ready_callback) {
3637 ret = ffs_obj->ffs_ready_callback(ffs);
3638 if (ret)
3639 goto done;
3640 }
3641
3642 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3643 done:
3644 ffs_dev_unlock();
3645 return ret;
3646 }
3647
3648 static void ffs_closed(struct ffs_data *ffs)
3649 {
3650 struct ffs_dev *ffs_obj;
3651 struct f_fs_opts *opts;
3652 struct config_item *ci;
3653
3654 ENTER();
3655 ffs_dev_lock();
3656
3657 ffs_obj = ffs->private_data;
3658 if (!ffs_obj)
3659 goto done;
3660
3661 ffs_obj->desc_ready = false;
3662 ffs_obj->ffs_data = NULL;
3663
3664 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3665 ffs_obj->ffs_closed_callback)
3666 ffs_obj->ffs_closed_callback(ffs);
3667
3668 if (ffs_obj->opts)
3669 opts = ffs_obj->opts;
3670 else
3671 goto done;
3672
3673 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3674 || !kref_read(&opts->func_inst.group.cg_item.ci_kref))
3675 goto done;
3676
3677 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
3678 ffs_dev_unlock();
3679
3680 if (test_bit(FFS_FL_BOUND, &ffs->flags))
3681 unregister_gadget_item(ci);
3682 return;
3683 done:
3684 ffs_dev_unlock();
3685 }
3686
3687 /* Misc helper functions ****************************************************/
3688
3689 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3690 {
3691 return nonblock
3692 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3693 : mutex_lock_interruptible(mutex);
3694 }
3695
3696 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3697 {
3698 char *data;
3699
3700 if (unlikely(!len))
3701 return NULL;
3702
3703 data = kmalloc(len, GFP_KERNEL);
3704 if (unlikely(!data))
3705 return ERR_PTR(-ENOMEM);
3706
3707 if (unlikely(copy_from_user(data, buf, len))) {
3708 kfree(data);
3709 return ERR_PTR(-EFAULT);
3710 }
3711
3712 pr_vdebug("Buffer from user space:\n");
3713 ffs_dump_mem("", data, len);
3714
3715 return data;
3716 }
3717
3718 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3719 MODULE_LICENSE("GPL");
3720 MODULE_AUTHOR("Michal Nazarewicz");
CRIS linux kernel tree