| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * f_fs.c -- user mode file system API for USB composite function controllers |
| * |
| * Copyright (C) 2010 Samsung Electronics |
| * Author: Michal Nazarewicz <mina86@mina86.com> |
| * |
| * Based on inode.c (GadgetFS) which was: |
| * Copyright (C) 2003-2004 David Brownell |
| * Copyright (C) 2003 Agilent Technologies |
| */ |
| |
| |
| /* #define DEBUG */ |
| /* #define VERBOSE_DEBUG */ |
| |
| #include <linux/blkdev.h> |
| #include <linux/pagemap.h> |
| #include <linux/export.h> |
| #include <linux/fs_parser.h> |
| #include <linux/hid.h> |
| #include <linux/mm.h> |
| #include <linux/module.h> |
| #include <linux/scatterlist.h> |
| #include <linux/sched/signal.h> |
| #include <linux/uio.h> |
| #include <linux/vmalloc.h> |
| #include <asm/unaligned.h> |
| |
| #include <linux/usb/ccid.h> |
| #include <linux/usb/composite.h> |
| #include <linux/usb/functionfs.h> |
| |
| #include <linux/aio.h> |
| #include <linux/kthread.h> |
| #include <linux/poll.h> |
| #include <linux/eventfd.h> |
| |
| #include "u_fs.h" |
| #include "u_f.h" |
| #include "u_os_desc.h" |
| #include "configfs.h" |
| |
| #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ |
| |
| /* Reference counter handling */ |
| static void ffs_data_get(struct ffs_data *ffs); |
| static void ffs_data_put(struct ffs_data *ffs); |
| /* Creates new ffs_data object. */ |
| static struct ffs_data *__must_check ffs_data_new(const char *dev_name) |
| __attribute__((malloc)); |
| |
| /* Opened counter handling. */ |
| static void ffs_data_opened(struct ffs_data *ffs); |
| static void ffs_data_closed(struct ffs_data *ffs); |
| |
| /* Called with ffs->mutex held; take over ownership of data. */ |
| static int __must_check |
| __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len); |
| static int __must_check |
| __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len); |
| |
| |
| /* The function structure ***************************************************/ |
| |
| struct ffs_ep; |
| |
| struct ffs_function { |
| struct usb_configuration *conf; |
| struct usb_gadget *gadget; |
| struct ffs_data *ffs; |
| |
| struct ffs_ep *eps; |
| u8 eps_revmap[16]; |
| short *interfaces_nums; |
| |
| struct usb_function function; |
| }; |
| |
| |
| static struct ffs_function *ffs_func_from_usb(struct usb_function *f) |
| { |
| return container_of(f, struct ffs_function, function); |
| } |
| |
| |
| static inline enum ffs_setup_state |
| ffs_setup_state_clear_cancelled(struct ffs_data *ffs) |
| { |
| return (enum ffs_setup_state) |
| cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP); |
| } |
| |
| |
| static void ffs_func_eps_disable(struct ffs_function *func); |
| static int __must_check ffs_func_eps_enable(struct ffs_function *func); |
| |
| static int ffs_func_bind(struct usb_configuration *, |
| struct usb_function *); |
| static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned); |
| static void ffs_func_disable(struct usb_function *); |
| static int ffs_func_setup(struct usb_function *, |
| const struct usb_ctrlrequest *); |
| static bool ffs_func_req_match(struct usb_function *, |
| const struct usb_ctrlrequest *, |
| bool config0); |
| static void ffs_func_suspend(struct usb_function *); |
| static void ffs_func_resume(struct usb_function *); |
| |
| |
| static int ffs_func_revmap_ep(struct ffs_function *func, u8 num); |
| static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf); |
| |
| |
| /* The endpoints structures *************************************************/ |
| |
| struct ffs_ep { |
| struct usb_ep *ep; /* P: ffs->eps_lock */ |
| struct usb_request *req; /* P: epfile->mutex */ |
| |
| /* [0]: full speed, [1]: high speed, [2]: super speed */ |
| struct usb_endpoint_descriptor *descs[3]; |
| |
| u8 num; |
| |
| int status; /* P: epfile->mutex */ |
| }; |
| |
| struct ffs_epfile { |
| /* Protects ep->ep and ep->req. */ |
| struct mutex mutex; |
| |
| struct ffs_data *ffs; |
| struct ffs_ep *ep; /* P: ffs->eps_lock */ |
| |
| struct dentry *dentry; |
| |
| /* |
| * Buffer for holding data from partial reads which may happen since |
| * we’re rounding user read requests to a multiple of a max packet size. |
| * |
| * The pointer is initialised with NULL value and may be set by |
| * __ffs_epfile_read_data function to point to a temporary buffer. |
| * |
| * In normal operation, calls to __ffs_epfile_read_buffered will consume |
| * data from said buffer and eventually free it. Importantly, while the |
| * function is using the buffer, it sets the pointer to NULL. This is |
| * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered |
| * can never run concurrently (they are synchronised by epfile->mutex) |
| * so the latter will not assign a new value to the pointer. |
| * |
| * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is |
| * valid) and sets the pointer to READ_BUFFER_DROP value. This special |
| * value is crux of the synchronisation between ffs_func_eps_disable and |
| * __ffs_epfile_read_data. |
| * |
| * Once __ffs_epfile_read_data is about to finish it will try to set the |
| * pointer back to its old value (as described above), but seeing as the |
| * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free |
| * the buffer. |
| * |
| * == State transitions == |
| * |
| * • ptr == NULL: (initial state) |
| * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP |
| * ◦ __ffs_epfile_read_buffered: nop |
| * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf |
| * ◦ reading finishes: n/a, not in ‘and reading’ state |
| * • ptr == DROP: |
| * ◦ __ffs_epfile_read_buffer_free: nop |
| * ◦ __ffs_epfile_read_buffered: go to ptr == NULL |
| * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop |
| * ◦ reading finishes: n/a, not in ‘and reading’ state |
| * • ptr == buf: |
| * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP |
| * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading |
| * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered |
| * is always called first |
| * ◦ reading finishes: n/a, not in ‘and reading’ state |
| * • ptr == NULL and reading: |
| * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading |
| * ◦ __ffs_epfile_read_buffered: n/a, mutex is held |
| * ◦ __ffs_epfile_read_data: n/a, mutex is held |
| * ◦ reading finishes and … |
| * … all data read: free buf, go to ptr == NULL |
| * … otherwise: go to ptr == buf and reading |
| * • ptr == DROP and reading: |
| * ◦ __ffs_epfile_read_buffer_free: nop |
| * ◦ __ffs_epfile_read_buffered: n/a, mutex is held |
| * ◦ __ffs_epfile_read_data: n/a, mutex is held |
| * ◦ reading finishes: free buf, go to ptr == DROP |
| */ |
| struct ffs_buffer *read_buffer; |
| #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN)) |
| |
| char name[5]; |
| |
| unsigned char in; /* P: ffs->eps_lock */ |
| unsigned char isoc; /* P: ffs->eps_lock */ |
| |
| unsigned char _pad; |
| }; |
| |
| struct ffs_buffer { |
| size_t length; |
| char *data; |
| char storage[]; |
| }; |
| |
| /* ffs_io_data structure ***************************************************/ |
| |
| struct ffs_io_data { |
| bool aio; |
| bool read; |
| |
| struct kiocb *kiocb; |
| struct iov_iter data; |
| const void *to_free; |
| char *buf; |
| |
| struct mm_struct *mm; |
| struct work_struct work; |
| |
| struct usb_ep *ep; |
| struct usb_request *req; |
| struct sg_table sgt; |
| bool use_sg; |
| |
| struct ffs_data *ffs; |
| }; |
| |
| struct ffs_desc_helper { |
| struct ffs_data *ffs; |
| unsigned interfaces_count; |
| unsigned eps_count; |
| }; |
| |
| static int __must_check ffs_epfiles_create(struct ffs_data *ffs); |
| static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count); |
| |
| static struct dentry * |
| ffs_sb_create_file(struct super_block *sb, const char *name, void *data, |
| const struct file_operations *fops); |
| |
| /* Devices management *******************************************************/ |
| |
| DEFINE_MUTEX(ffs_lock); |
| EXPORT_SYMBOL_GPL(ffs_lock); |
| |
| static struct ffs_dev *_ffs_find_dev(const char *name); |
| static struct ffs_dev *_ffs_alloc_dev(void); |
| static void _ffs_free_dev(struct ffs_dev *dev); |
| static void *ffs_acquire_dev(const char *dev_name); |
| static void ffs_release_dev(struct ffs_data *ffs_data); |
| static int ffs_ready(struct ffs_data *ffs); |
| static void ffs_closed(struct ffs_data *ffs); |
| |
| /* Misc helper functions ****************************************************/ |
| |
| static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) |
| __attribute__((warn_unused_result, nonnull)); |
| static char *ffs_prepare_buffer(const char __user *buf, size_t len) |
| __attribute__((warn_unused_result, nonnull)); |
| |
| |
| /* Control file aka ep0 *****************************************************/ |
| |
| static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req) |
| { |
| struct ffs_data *ffs = req->context; |
| |
| complete(&ffs->ep0req_completion); |
| } |
| |
| static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len) |
| __releases(&ffs->ev.waitq.lock) |
| { |
| struct usb_request *req = ffs->ep0req; |
| int ret; |
| |
| req->zero = len < le16_to_cpu(ffs->ev.setup.wLength); |
| |
| spin_unlock_irq(&ffs->ev.waitq.lock); |
| |
| req->buf = data; |
| req->length = len; |
| |
| /* |
| * UDC layer requires to provide a buffer even for ZLP, but should |
| * not use it at all. Let's provide some poisoned pointer to catch |
| * possible bug in the driver. |
| */ |
| if (req->buf == NULL) |
| req->buf = (void *)0xDEADBABE; |
| |
| reinit_completion(&ffs->ep0req_completion); |
| |
| ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC); |
| if (unlikely(ret < 0)) |
| return ret; |
| |
| ret = wait_for_completion_interruptible(&ffs->ep0req_completion); |
| if (unlikely(ret)) { |
| usb_ep_dequeue(ffs->gadget->ep0, req); |
| return -EINTR; |
| } |
| |
| ffs->setup_state = FFS_NO_SETUP; |
| return req->status ? req->status : req->actual; |
| } |
| |
| static int __ffs_ep0_stall(struct ffs_data *ffs) |
| { |
| if (ffs->ev.can_stall) { |
| pr_vdebug("ep0 stall\n"); |
| usb_ep_set_halt(ffs->gadget->ep0); |
| ffs->setup_state = FFS_NO_SETUP; |
| return -EL2HLT; |
| } else { |
| pr_debug("bogus ep0 stall!\n"); |
| return -ESRCH; |
| } |
| } |
| |
| static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, |
| size_t len, loff_t *ptr) |
| { |
| struct ffs_data *ffs = file->private_data; |
| ssize_t ret; |
| char *data; |
| |
| ENTER(); |
| |
| /* Fast check if setup was canceled */ |
| if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) |
| return -EIDRM; |
| |
| /* Acquire mutex */ |
| ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); |
| if (unlikely(ret < 0)) |
| return ret; |
| |
| /* Check state */ |
| switch (ffs->state) { |
| case FFS_READ_DESCRIPTORS: |
| case FFS_READ_STRINGS: |
| /* Copy data */ |
| if (unlikely(len < 16)) { |
| ret = -EINVAL; |
| break; |
| } |
| |
| data = ffs_prepare_buffer(buf, len); |
| if (IS_ERR(data)) { |
| ret = PTR_ERR(data); |
| break; |
| } |
| |
| /* Handle data */ |
| if (ffs->state == FFS_READ_DESCRIPTORS) { |
| pr_info("read descriptors\n"); |
| ret = __ffs_data_got_descs(ffs, data, len); |
| if (unlikely(ret < 0)) |
| break; |
| |
| ffs->state = FFS_READ_STRINGS; |
| ret = len; |
| } else { |
| pr_info("read strings\n"); |
| ret = __ffs_data_got_strings(ffs, data, len); |
| if (unlikely(ret < 0)) |
| break; |
| |
| ret = ffs_epfiles_create(ffs); |
| if (unlikely(ret)) { |
| ffs->state = FFS_CLOSING; |
| break; |
| } |
| |
| ffs->state = FFS_ACTIVE; |
| mutex_unlock(&ffs->mutex); |
| |
| ret = ffs_ready(ffs); |
| if (unlikely(ret < 0)) { |
| ffs->state = FFS_CLOSING; |
| return ret; |
| } |
| |
| return len; |
| } |
| break; |
| |
| case FFS_ACTIVE: |
| data = NULL; |
| /* |
| * We're called from user space, we can use _irq |
| * rather then _irqsave |
| */ |
| spin_lock_irq(&ffs->ev.waitq.lock); |
| switch (ffs_setup_state_clear_cancelled(ffs)) { |
| case FFS_SETUP_CANCELLED: |
| ret = -EIDRM; |
| goto done_spin; |
| |
| case FFS_NO_SETUP: |
| ret = -ESRCH; |
| goto done_spin; |
| |
| case FFS_SETUP_PENDING: |
| break; |
| } |
| |
| /* FFS_SETUP_PENDING */ |
| if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) { |
| spin_unlock_irq(&ffs->ev.waitq.lock); |
| ret = __ffs_ep0_stall(ffs); |
| break; |
| } |
| |
| /* FFS_SETUP_PENDING and not stall */ |
| len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); |
| |
| spin_unlock_irq(&ffs->ev.waitq.lock); |
| |
| data = ffs_prepare_buffer(buf, len); |
| if (IS_ERR(data)) { |
| ret = PTR_ERR(data); |
| break; |
| } |
| |
| spin_lock_irq(&ffs->ev.waitq.lock); |
| |
| /* |
| * We are guaranteed to be still in FFS_ACTIVE state |
| * but the state of setup could have changed from |
| * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need |
| * to check for that. If that happened we copied data |
| * from user space in vain but it's unlikely. |
| * |
| * For sure we are not in FFS_NO_SETUP since this is |
| * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP |
| * transition can be performed and it's protected by |
| * mutex. |
| */ |
| if (ffs_setup_state_clear_cancelled(ffs) == |
| FFS_SETUP_CANCELLED) { |
| ret = -EIDRM; |
| done_spin: |
| spin_unlock_irq(&ffs->ev.waitq.lock); |
| } else { |
| /* unlocks spinlock */ |
| ret = __ffs_ep0_queue_wait(ffs, data, len); |
| } |
| kfree(data); |
| break; |
| |
| default: |
| ret = -EBADFD; |
| break; |
| } |
| |
| mutex_unlock(&ffs->mutex); |
| return ret; |
| } |
| |
| /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */ |
| static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf, |
| size_t n) |
| __releases(&ffs->ev.waitq.lock) |
| { |
| /* |
| * n cannot be bigger than ffs->ev.count, which cannot be bigger than |
| * size of ffs->ev.types array (which is four) so that's how much space |
| * we reserve. |
| */ |
| struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)]; |
| const size_t size = n * sizeof *events; |
| unsigned i = 0; |
| |
| memset(events, 0, size); |
| |
| do { |
| events[i].type = ffs->ev.types[i]; |
| if (events[i].type == FUNCTIONFS_SETUP) { |
| events[i].u.setup = ffs->ev.setup; |
| ffs->setup_state = FFS_SETUP_PENDING; |
| } |
| } while (++i < n); |
| |
| ffs->ev.count -= n; |
| if (ffs->ev.count) |
| memmove(ffs->ev.types, ffs->ev.types + n, |
| ffs->ev.count * sizeof *ffs->ev.types); |
| |
| spin_unlock_irq(&ffs->ev.waitq.lock); |
| mutex_unlock(&ffs->mutex); |
| |
| return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size; |
| } |
| |
| static ssize_t ffs_ep0_read(struct file *file, char __user *buf, |
| size_t len, loff_t *ptr) |
| { |
| struct ffs_data *ffs = file->private_data; |
| char *data = NULL; |
| size_t n; |
| int ret; |
| |
| ENTER(); |
| |
| /* Fast check if setup was canceled */ |
| if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) |
| return -EIDRM; |
| |
| /* Acquire mutex */ |
| ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); |
| if (unlikely(ret < 0)) |
| return ret; |
| |
| /* Check state */ |
| if (ffs->state != FFS_ACTIVE) { |
| ret = -EBADFD; |
| goto done_mutex; |
| } |
| |
| /* |
| * We're called from user space, we can use _irq rather then |
| * _irqsave |
| */ |
| spin_lock_irq(&ffs->ev.waitq.lock); |
| |
| switch (ffs_setup_state_clear_cancelled(ffs)) { |
| case FFS_SETUP_CANCELLED: |
| ret = -EIDRM; |
| break; |
| |
| case FFS_NO_SETUP: |
| n = len / sizeof(struct usb_functionfs_event); |
| if (unlikely(!n)) { |
| ret = -EINVAL; |
| break; |
| } |
| |
| if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) { |
| ret = -EAGAIN; |
| break; |
| } |
| |
| if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, |
| ffs->ev.count)) { |
| ret = -EINTR; |
| break; |
| } |
| |
| /* unlocks spinlock */ |
| return __ffs_ep0_read_events(ffs, buf, |
| min(n, (size_t)ffs->ev.count)); |
| |
| case FFS_SETUP_PENDING: |
| if (ffs->ev.setup.bRequestType & USB_DIR_IN) { |
| spin_unlock_irq(&ffs->ev.waitq.lock); |
| ret = __ffs_ep0_stall(ffs); |
| goto done_mutex; |
| } |
| |
| len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); |
| |
| spin_unlock_irq(&ffs->ev.waitq.lock); |
| |
| if (likely(len)) { |
| data = kmalloc(len, GFP_KERNEL); |
| if (unlikely(!data)) { |
| ret = -ENOMEM; |
| goto done_mutex; |
| } |
| } |
| |
| spin_lock_irq(&ffs->ev.waitq.lock); |
| |
| /* See ffs_ep0_write() */ |
| if (ffs_setup_state_clear_cancelled(ffs) == |
| FFS_SETUP_CANCELLED) { |
| ret = -EIDRM; |
| break; |
| } |
| |
| /* unlocks spinlock */ |
| ret = __ffs_ep0_queue_wait(ffs, data, len); |
| if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len))) |
| ret = -EFAULT; |
| goto done_mutex; |
| |
| default: |
| ret = -EBADFD; |
| break; |
| } |
| |
| spin_unlock_irq(&ffs->ev.waitq.lock); |
| done_mutex: |
| mutex_unlock(&ffs->mutex); |
| kfree(data); |
| return ret; |
| } |
| |
| static int ffs_ep0_open(struct inode *inode, struct file *file) |
| { |
| struct ffs_data *ffs = inode->i_private; |
| |
| ENTER(); |
| |
| if (unlikely(ffs->state == FFS_CLOSING)) |
| return -EBUSY; |
| |
| file->private_data = ffs; |
| ffs_data_opened(ffs); |
| |
| return 0; |
| } |
| |
| static int ffs_ep0_release(struct inode *inode, struct file *file) |
| { |
| struct ffs_data *ffs = file->private_data; |
| |
| ENTER(); |
| |
| ffs_data_closed(ffs); |
| |
| return 0; |
| } |
| |
| static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) |
| { |
| struct ffs_data *ffs = file->private_data; |
| struct usb_gadget *gadget = ffs->gadget; |
| long ret; |
| |
| ENTER(); |
| |
| if (code == FUNCTIONFS_INTERFACE_REVMAP) { |
| struct ffs_function *func = ffs->func; |
| ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV; |
| } else if (gadget && gadget->ops->ioctl) { |
| ret = gadget->ops->ioctl(gadget, code, value); |
| } else { |
| ret = -ENOTTY; |
| } |
| |
| return ret; |
| } |
| |
| static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait) |
| { |
| struct ffs_data *ffs = file->private_data; |
| __poll_t mask = EPOLLWRNORM; |
| int ret; |
| |
| poll_wait(file, &ffs->ev.waitq, wait); |
| |
| ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); |
| if (unlikely(ret < 0)) |
| return mask; |
| |
| switch (ffs->state) { |
| case FFS_READ_DESCRIPTORS: |
| case FFS_READ_STRINGS: |
| mask |= EPOLLOUT; |
| break; |
| |
| case FFS_ACTIVE: |
| switch (ffs->setup_state) { |
| case FFS_NO_SETUP: |
| if (ffs->ev.count) |
| mask |= EPOLLIN; |
| break; |
| |
| case FFS_SETUP_PENDING: |
| case FFS_SETUP_CANCELLED: |
| mask |= (EPOLLIN | EPOLLOUT); |
| break; |
| } |
| case FFS_CLOSING: |
| break; |
| case FFS_DEACTIVATED: |
| break; |
| } |
| |
| mutex_unlock(&ffs->mutex); |
| |
| return mask; |
| } |
| |
| static const struct file_operations ffs_ep0_operations = { |
| .llseek = no_llseek, |
| |
| .open = ffs_ep0_open, |
| .write = ffs_ep0_write, |
| .read = ffs_ep0_read, |
| .release = ffs_ep0_release, |
| .unlocked_ioctl = ffs_ep0_ioctl, |
| .poll = ffs_ep0_poll, |
| }; |
| |
| |
| /* "Normal" endpoints operations ********************************************/ |
| |
| static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) |
| { |
| ENTER(); |
| if (likely(req->context)) { |
| struct ffs_ep *ep = _ep->driver_data; |
| ep->status = req->status ? req->status : req->actual; |
| complete(req->context); |
| } |
| } |
| |
| static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter) |
| { |
| ssize_t ret = copy_to_iter(data, data_len, iter); |
| if (likely(ret == data_len)) |
| return ret; |
| |
| if (unlikely(iov_iter_count(iter))) |
| return -EFAULT; |
| |
| /* |
| * Dear user space developer! |
| * |
| * TL;DR: To stop getting below error message in your kernel log, change |
| * user space code using functionfs to align read buffers to a max |
| * packet size. |
| * |
| * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max |
| * packet size. When unaligned buffer is passed to functionfs, it |
| * internally uses a larger, aligned buffer so that such UDCs are happy. |
| * |
| * Unfortunately, this means that host may send more data than was |
| * requested in read(2) system call. f_fs doesn’t know what to do with |
| * that excess data so it simply drops it. |
| * |
| * Was the buffer aligned in the first place, no such problem would |
| * happen. |
| * |
| * Data may be dropped only in AIO reads. Synchronous reads are handled |
| * by splitting a request into multiple parts. This splitting may still |
| * be a problem though so it’s likely best to align the buffer |
| * regardless of it being AIO or not.. |
| * |
| * This only affects OUT endpoints, i.e. reading data with a read(2), |
| * aio_read(2) etc. system calls. Writing data to an IN endpoint is not |
| * affected. |
| */ |
| pr_err("functionfs read size %d > requested size %zd, dropping excess data. " |
| "Align read buffer size to max packet size to avoid the problem.\n", |
| data_len, ret); |
| |
| return ret; |
| } |
| |
| /* |
| * allocate a virtually contiguous buffer and create a scatterlist describing it |
| * @sg_table - pointer to a place to be filled with sg_table contents |
| * @size - required buffer size |
| */ |
| static void *ffs_build_sg_list(struct sg_table *sgt, size_t sz) |
| { |
| struct page **pages; |
| void *vaddr, *ptr; |
| unsigned int n_pages; |
| int i; |
| |
| vaddr = vmalloc(sz); |
| if (!vaddr) |
| return NULL; |
| |
| n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT; |
| pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL); |
| if (!pages) { |
| vfree(vaddr); |
| |
| return NULL; |
| } |
| for (i = 0, ptr = vaddr; i < n_pages; ++i, ptr += PAGE_SIZE) |
| pages[i] = vmalloc_to_page(ptr); |
| |
| if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) { |
| kvfree(pages); |
| vfree(vaddr); |
| |
| return NULL; |
| } |
| kvfree(pages); |
| |
| return vaddr; |
| } |
| |
| static inline void *ffs_alloc_buffer(struct ffs_io_data *io_data, |
| size_t data_len) |
| { |
| if (io_data->use_sg) |
| return ffs_build_sg_list(&io_data->sgt, data_len); |
| |
| return kmalloc(data_len, GFP_KERNEL); |
| } |
| |
| static inline void ffs_free_buffer(struct ffs_io_data *io_data) |
| { |
| if (!io_data->buf) |
| return; |
| |
| if (io_data->use_sg) { |
| sg_free_table(&io_data->sgt); |
| vfree(io_data->buf); |
| } else { |
| kfree(io_data->buf); |
| } |
| } |
| |
| static void ffs_user_copy_worker(struct work_struct *work) |
| { |
| struct ffs_io_data *io_data = container_of(work, struct ffs_io_data, |
| work); |
| int ret = io_data->req->status ? io_data->req->status : |
| io_data->req->actual; |
| bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD; |
| |
| if (io_data->read && ret > 0) { |
| kthread_use_mm(io_data->mm); |
| ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); |
| kthread_unuse_mm(io_data->mm); |
| } |
| |
| io_data->kiocb->ki_complete(io_data->kiocb, ret, ret); |
| |
| if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd) |
| eventfd_signal(io_data->ffs->ffs_eventfd, 1); |
| |
| usb_ep_free_request(io_data->ep, io_data->req); |
| |
| if (io_data->read) |
| kfree(io_data->to_free); |
| ffs_free_buffer(io_data); |
| kfree(io_data); |
| } |
| |
| static void ffs_epfile_async_io_complete(struct usb_ep *_ep, |
| struct usb_request *req) |
| { |
| struct ffs_io_data *io_data = req->context; |
| struct ffs_data *ffs = io_data->ffs; |
| |
| ENTER(); |
| |
| INIT_WORK(&io_data->work, ffs_user_copy_worker); |
| queue_work(ffs->io_completion_wq, &io_data->work); |
| } |
| |
| static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile) |
| { |
| /* |
| * See comment in struct ffs_epfile for full read_buffer pointer |
| * synchronisation story. |
| */ |
| struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP); |
| if (buf && buf != READ_BUFFER_DROP) |
| kfree(buf); |
| } |
| |
| /* Assumes epfile->mutex is held. */ |
| static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile, |
| struct iov_iter *iter) |
| { |
| /* |
| * Null out epfile->read_buffer so ffs_func_eps_disable does not free |
| * the buffer while we are using it. See comment in struct ffs_epfile |
| * for full read_buffer pointer synchronisation story. |
| */ |
| struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL); |
| ssize_t ret; |
| if (!buf || buf == READ_BUFFER_DROP) |
| return 0; |
| |
| ret = copy_to_iter(buf->data, buf->length, iter); |
| if (buf->length == ret) { |
| kfree(buf); |
| return ret; |
| } |
| |
| if (unlikely(iov_iter_count(iter))) { |
| ret = -EFAULT; |
| } else { |
| buf->length -= ret; |
| buf->data += ret; |
| } |
| |
| if (cmpxchg(&epfile->read_buffer, NULL, buf)) |
| kfree(buf); |
| |
| return ret; |
| } |
| |
| /* Assumes epfile->mutex is held. */ |
| static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile, |
| void *data, int data_len, |
| struct iov_iter *iter) |
| { |
| struct ffs_buffer *buf; |
| |
| ssize_t ret = copy_to_iter(data, data_len, iter); |
| if (likely(data_len == ret)) |
| return ret; |
| |
| if (unlikely(iov_iter_count(iter))) |
| return -EFAULT; |
| |
| /* See ffs_copy_to_iter for more context. */ |
| pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.", |
| data_len, ret); |
| |
| data_len -= ret; |
| buf = kmalloc(sizeof(*buf) + data_len, GFP_KERNEL); |
| if (!buf) |
| return -ENOMEM; |
| buf->length = data_len; |
| buf->data = buf->storage; |
| memcpy(buf->storage, data + ret, data_len); |
| |
| /* |
| * At this point read_buffer is NULL or READ_BUFFER_DROP (if |
| * ffs_func_eps_disable has been called in the meanwhile). See comment |
| * in struct ffs_epfile for full read_buffer pointer synchronisation |
| * story. |
| */ |
| if (unlikely(cmpxchg(&epfile->read_buffer, NULL, buf))) |
| kfree(buf); |
| |
| return ret; |
| } |
| |
| static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) |
| { |
| struct ffs_epfile *epfile = file->private_data; |
| struct usb_request *req; |
| struct ffs_ep *ep; |
| char *data = NULL; |
| ssize_t ret, data_len = -EINVAL; |
| int halt; |
| |
| /* Are we still active? */ |
| if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) |
| return -ENODEV; |
| |
| /* Wait for endpoint to be enabled */ |
| ep = epfile->ep; |
| if (!ep) { |
| if (file->f_flags & O_NONBLOCK) |
| return -EAGAIN; |
| |
| ret = wait_event_interruptible( |
| epfile->ffs->wait, (ep = epfile->ep)); |
| if (ret) |
| return -EINTR; |
| } |
| |
| /* Do we halt? */ |
| halt = (!io_data->read == !epfile->in); |
| if (halt && epfile->isoc) |
| return -EINVAL; |
| |
| /* We will be using request and read_buffer */ |
| ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK); |
| if (unlikely(ret)) |
| goto error; |
| |
| /* Allocate & copy */ |
| if (!halt) { |
| struct usb_gadget *gadget; |
| |
| /* |
| * Do we have buffered data from previous partial read? Check |
| * that for synchronous case only because we do not have |
| * facility to ‘wake up’ a pending asynchronous read and push |
| * buffered data to it which we would need to make things behave |
| * consistently. |
| */ |
| if (!io_data->aio && io_data->read) { |
| ret = __ffs_epfile_read_buffered(epfile, &io_data->data); |
| if (ret) |
| goto error_mutex; |
| } |
| |
| /* |
| * if we _do_ wait above, the epfile->ffs->gadget might be NULL |
| * before the waiting completes, so do not assign to 'gadget' |
| * earlier |
| */ |
| gadget = epfile->ffs->gadget; |
| |
| spin_lock_irq(&epfile->ffs->eps_lock); |
| /* In the meantime, endpoint got disabled or changed. */ |
| if (epfile->ep != ep) { |
| ret = -ESHUTDOWN; |
| goto error_lock; |
| } |
| data_len = iov_iter_count(&io_data->data); |
| /* |
| * Controller may require buffer size to be aligned to |
| * maxpacketsize of an out endpoint. |
| */ |
| if (io_data->read) |
| data_len = usb_ep_align_maybe(gadget, ep->ep, data_len); |
| |
| io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE; |
| spin_unlock_irq(&epfile->ffs->eps_lock); |
| |
| data = ffs_alloc_buffer(io_data, data_len); |
| if (unlikely(!data)) { |
| ret = -ENOMEM; |
| goto error_mutex; |
| } |
| if (!io_data->read && |
| !copy_from_iter_full(data, data_len, &io_data->data)) { |
| ret = -EFAULT; |
| goto error_mutex; |
| } |
| } |
| |
| spin_lock_irq(&epfile->ffs->eps_lock); |
| |
| if (epfile->ep != ep) { |
| /* In the meantime, endpoint got disabled or changed. */ |
| ret = -ESHUTDOWN; |
| } else if (halt) { |
| ret = usb_ep_set_halt(ep->ep); |
| if (!ret) |
| ret = -EBADMSG; |
| } else if (unlikely(data_len == -EINVAL)) { |
| /* |
| * Sanity Check: even though data_len can't be used |
| * uninitialized at the time I write this comment, some |
| * compilers complain about this situation. |
| * In order to keep the code clean from warnings, data_len is |
| * being initialized to -EINVAL during its declaration, which |
| * means we can't rely on compiler anymore to warn no future |
| * changes won't result in data_len being used uninitialized. |
| * For such reason, we're adding this redundant sanity check |
| * here. |
| */ |
| WARN(1, "%s: data_len == -EINVAL\n", __func__); |
| ret = -EINVAL; |
| } else if (!io_data->aio) { |
| DECLARE_COMPLETION_ONSTACK(done); |
| bool interrupted = false; |
| |
| req = ep->req; |
| if (io_data->use_sg) { |
| req->buf = NULL; |
| req->sg = io_data->sgt.sgl; |
| req->num_sgs = io_data->sgt.nents; |
| } else { |
| req->buf = data; |
| req->num_sgs = 0; |
| } |
| req->length = data_len; |
| |
| io_data->buf = data; |
| |
| req->context = &done; |
| req->complete = ffs_epfile_io_complete; |
| |
| ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); |
| if (unlikely(ret < 0)) |
| goto error_lock; |
| |
| spin_unlock_irq(&epfile->ffs->eps_lock); |
| |
| if (unlikely(wait_for_completion_interruptible(&done))) { |
| /* |
| * To avoid race condition with ffs_epfile_io_complete, |
| * dequeue the request first then check |
| * status. usb_ep_dequeue API should guarantee no race |
| * condition with req->complete callback. |
| */ |
| usb_ep_dequeue(ep->ep, req); |
| wait_for_completion(&done); |
| interrupted = ep->status < 0; |
| } |
| |
| if (interrupted) |
| ret = -EINTR; |
| else if (io_data->read && ep->status > 0) |
| ret = __ffs_epfile_read_data(epfile, data, ep->status, |
| &io_data->data); |
| else |
| ret = ep->status; |
| goto error_mutex; |
| } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) { |
| ret = -ENOMEM; |
| } else { |
| if (io_data->use_sg) { |
| req->buf = NULL; |
| req->sg = io_data->sgt.sgl; |
| req->num_sgs = io_data->sgt.nents; |
| } else { |
| req->buf = data; |
| req->num_sgs = 0; |
| } |
| req->length = data_len; |
| |
| io_data->buf = data; |
| io_data->ep = ep->ep; |
| io_data->req = req; |
| io_data->ffs = epfile->ffs; |
| |
| req->context = io_data; |
| req->complete = ffs_epfile_async_io_complete; |
| |
| ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); |
| if (unlikely(ret)) { |
| io_data->req = NULL; |
| usb_ep_free_request(ep->ep, req); |
| goto error_lock; |
| } |
| |
| ret = -EIOCBQUEUED; |
| /* |
| * Do not kfree the buffer in this function. It will be freed |
| * by ffs_user_copy_worker. |
| */ |
| data = NULL; |
| } |
| |
| error_lock: |
| spin_unlock_irq(&epfile->ffs->eps_lock); |
| error_mutex: |
| mutex_unlock(&epfile->mutex); |
| error: |
| if (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */ |
| ffs_free_buffer(io_data); |
| return ret; |
| } |
| |
| static int |
| ffs_epfile_open(struct inode *inode, struct file *file) |
| { |
| struct ffs_epfile *epfile = inode->i_private; |
| |
| ENTER(); |
| |
| if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) |
| return -ENODEV; |
| |
| file->private_data = epfile; |
| ffs_data_opened(epfile->ffs); |
| |
| return 0; |
| } |
| |
| static int ffs_aio_cancel(struct kiocb *kiocb) |
| { |
| struct ffs_io_data *io_data = kiocb->private; |
| struct ffs_epfile *epfile = kiocb->ki_filp->private_data; |
| unsigned long flags; |
| int value; |
| |
| ENTER(); |
| |
| spin_lock_irqsave(&epfile->ffs->eps_lock, flags); |
| |
| if (likely(io_data && io_data->ep && io_data->req)) |
| value = usb_ep_dequeue(io_data->ep, io_data->req); |
| else |
| value = -EINVAL; |
| |
| spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags); |
| |
| return value; |
| } |
| |
| static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from) |
| { |
| struct ffs_io_data io_data, *p = &io_data; |
| ssize_t res; |
| |
| ENTER(); |
| |
| if (!is_sync_kiocb(kiocb)) { |
| p = kzalloc(sizeof(io_data), GFP_KERNEL); |
| if (unlikely(!p)) |
| return -ENOMEM; |
| p->aio = true; |
| } else { |
| memset(p, 0, sizeof(*p)); |
| p->aio = false; |
| } |
| |
| p->read = false; |
| p->kiocb = kiocb; |
| p->data = *from; |
| p->mm = current->mm; |
| |
| kiocb->private = p; |
| |
| if (p->aio) |
| kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); |
| |
| res = ffs_epfile_io(kiocb->ki_filp, p); |
| if (res == -EIOCBQUEUED) |
| return res; |
| if (p->aio) |
| kfree(p); |
| else |
| *from = p->data; |
| return res; |
| } |
| |
| static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) |
| { |
| struct ffs_io_data io_data, *p = &io_data; |
| ssize_t res; |
| |
| ENTER(); |
| |
| if (!is_sync_kiocb(kiocb)) { |
| p = kzalloc(sizeof(io_data), GFP_KERNEL); |
| if (unlikely(!p)) |
| return -ENOMEM; |
| p->aio = true; |
| } else { |
| memset(p, 0, sizeof(*p)); |
| p->aio = false; |
| } |
| |
| p->read = true; |
| p->kiocb = kiocb; |
| if (p->aio) { |
| p->to_free = dup_iter(&p->data, to, GFP_KERNEL); |
| if (!p->to_free) { |
| kfree(p); |
| return -ENOMEM; |
| } |
| } else { |
| p->data = *to; |
| p->to_free = NULL; |
| } |
| p->mm = current->mm; |
| |
| kiocb->private = p; |
| |
| if (p->aio) |
| kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); |
| |
| res = ffs_epfile_io(kiocb->ki_filp, p); |
| if (res == -EIOCBQUEUED) |
| return res; |
| |
| if (p->aio) { |
| kfree(p->to_free); |
| kfree(p); |
| } else { |
| *to = p->data; |
| } |
| return res; |
| } |
| |
| static int |
| ffs_epfile_release(struct inode *inode, struct file *file) |
| { |
| struct ffs_epfile *epfile = inode->i_private; |
| |
| ENTER(); |
| |
| __ffs_epfile_read_buffer_free(epfile); |
| ffs_data_closed(epfile->ffs); |
| |
| return 0; |
| } |
| |
| static long ffs_epfile_ioctl(struct file *file, unsigned code, |
| unsigned long value) |
| { |
| struct ffs_epfile *epfile = file->private_data; |
| struct ffs_ep *ep; |
| int ret; |
| |
| ENTER(); |
| |
| if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) |
| return -ENODEV; |
| |
| /* Wait for endpoint to be enabled */ |
| ep = epfile->ep; |
| if (!ep) { |
| if (file->f_flags & O_NONBLOCK) |
| return -EAGAIN; |
| |
| ret = wait_event_interruptible( |
| epfile->ffs->wait, (ep = epfile->ep)); |
| if (ret) |
| return -EINTR; |
| } |
| |
| spin_lock_irq(&epfile->ffs->eps_lock); |
| |
| /* In the meantime, endpoint got disabled or changed. */ |
| if (epfile->ep != ep) { |
| spin_unlock_irq(&epfile->ffs->eps_lock); |
| return -ESHUTDOWN; |
| } |
| |
| switch (code) { |
| case FUNCTIONFS_FIFO_STATUS: |
| ret = usb_ep_fifo_status(epfile->ep->ep); |
| break; |
| case FUNCTIONFS_FIFO_FLUSH: |
| usb_ep_fifo_flush(epfile->ep->ep); |
| ret = 0; |
| break; |
| case FUNCTIONFS_CLEAR_HALT: |
| ret = usb_ep_clear_halt(epfile->ep->ep); |
| break; |
| case FUNCTIONFS_ENDPOINT_REVMAP: |
| ret = epfile->ep->num; |
| break; |
| case FUNCTIONFS_ENDPOINT_DESC: |
| { |
| int desc_idx; |
| struct usb_endpoint_descriptor *desc; |
| |
| switch (epfile->ffs->gadget->speed) { |
| case USB_SPEED_SUPER: |
| desc_idx = 2; |
| break; |
| case USB_SPEED_HIGH: |
| desc_idx = 1; |
| break; |
| default: |
| desc_idx = 0; |
| } |
| desc = epfile->ep->descs[desc_idx]; |
| |
| spin_unlock_irq(&epfile->ffs->eps_lock); |
| ret = copy_to_user((void __user *)value, desc, desc->bLength); |
| if (ret) |
| ret = -EFAULT; |
| return ret; |
| } |
| default: |
| ret = -ENOTTY; |
| } |
| spin_unlock_irq(&epfile->ffs->eps_lock); |
| |
| return ret; |
| } |
| |
| static const struct file_operations ffs_epfile_operations = { |
| .llseek = no_llseek, |
| |
| .open = ffs_epfile_open, |
| .write_iter = ffs_epfile_write_iter, |
| .read_iter = ffs_epfile_read_iter, |
| .release = ffs_epfile_release, |
| .unlocked_ioctl = ffs_epfile_ioctl, |
| .compat_ioctl = compat_ptr_ioctl, |
| }; |
| |
| |
| /* File system and super block operations ***********************************/ |
| |
| /* |
| * Mounting the file system creates a controller file, used first for |
| * function configuration then later for event monitoring. |
| */ |
| |
| static struct inode *__must_check |
| ffs_sb_make_inode(struct super_block *sb, void *data, |
| const struct file_operations *fops, |
| const struct inode_operations *iops, |
| struct ffs_file_perms *perms) |
| { |
| struct inode *inode; |
| |
| ENTER(); |
| |
| inode = new_inode(sb); |
| |
| if (likely(inode)) { |
| struct timespec64 ts = current_time(inode); |
| |
| inode->i_ino = get_next_ino(); |
| inode->i_mode = perms->mode; |
| inode->i_uid = perms->uid; |
| inode->i_gid = perms->gid; |
| inode->i_atime = ts; |
| inode->i_mtime = ts; |
| inode->i_ctime = ts; |
| inode->i_private = data; |
| if (fops) |
| inode->i_fop = fops; |
| if (iops) |
| inode->i_op = iops; |
| } |
| |
| return inode; |
| } |
| |
| /* Create "regular" file */ |
| static struct dentry *ffs_sb_create_file(struct super_block *sb, |
| const char *name, void *data, |
| const struct file_operations *fops) |
| { |
| struct ffs_data *ffs = sb->s_fs_info; |
| struct dentry *dentry; |
| struct inode *inode; |
| |
| ENTER(); |
| |
| dentry = d_alloc_name(sb->s_root, name); |
| if (unlikely(!dentry)) |
| return NULL; |
| |
| inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms); |
| if (unlikely(!inode)) { |
| dput(dentry); |
| return NULL; |
| } |
| |
| d_add(dentry, inode); |
| return dentry; |
| } |
| |
| /* Super block */ |
| static const struct super_operations ffs_sb_operations = { |
| .statfs = simple_statfs, |
| .drop_inode = generic_delete_inode, |
| }; |
| |
| struct ffs_sb_fill_data { |
| struct ffs_file_perms perms; |
| umode_t root_mode; |
| const char *dev_name; |
| bool no_disconnect; |
| struct ffs_data *ffs_data; |
| }; |
| |
| static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc) |
| { |
| struct ffs_sb_fill_data *data = fc->fs_private; |
| struct inode *inode; |
| struct ffs_data *ffs = data->ffs_data; |
| |
| ENTER(); |
| |
| ffs->sb = sb; |
| data->ffs_data = NULL; |
| sb->s_fs_info = ffs; |
| sb->s_blocksize = PAGE_SIZE; |
| sb->s_blocksize_bits = PAGE_SHIFT; |
| sb->s_magic = FUNCTIONFS_MAGIC; |
| sb->s_op = &ffs_sb_operations; |
| sb->s_time_gran = 1; |
| |
| /* Root inode */ |
| data->perms.mode = data->root_mode; |
| inode = ffs_sb_make_inode(sb, NULL, |
| &simple_dir_operations, |
| &simple_dir_inode_operations, |
| &data->perms); |
| sb->s_root = d_make_root(inode); |
| if (unlikely(!sb->s_root)) |
| return -ENOMEM; |
| |
| /* EP0 file */ |
| if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs, |
| &ffs_ep0_operations))) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| enum { |
| Opt_no_disconnect, |
| Opt_rmode, |
| Opt_fmode, |
| Opt_mode, |
| Opt_uid, |
| Opt_gid, |
| }; |
| |
| static const struct fs_parameter_spec ffs_fs_fs_parameters[] = { |
| fsparam_bool ("no_disconnect", Opt_no_disconnect), |
| fsparam_u32 ("rmode", Opt_rmode), |
| fsparam_u32 ("fmode", Opt_fmode), |
| fsparam_u32 ("mode", Opt_mode), |
| fsparam_u32 ("uid", Opt_uid), |
| fsparam_u32 ("gid", Opt_gid), |
| {} |
| }; |
| |
| static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param) |
| { |
| struct ffs_sb_fill_data *data = fc->fs_private; |
| struct fs_parse_result result; |
| int opt; |
| |
| ENTER(); |
| |
| opt = fs_parse(fc, ffs_fs_fs_parameters, param, &result); |
| if (opt < 0) |
| return opt; |
| |
| switch (opt) { |
| case Opt_no_disconnect: |
| data->no_disconnect = result.boolean; |
| break; |
| case Opt_rmode: |
| data->root_mode = (result.uint_32 & 0555) | S_IFDIR; |
| break; |
| case Opt_fmode: |
| data->perms.mode = (result.uint_32 & 0666) | S_IFREG; |
| break; |
| case Opt_mode: |
| data->root_mode = (result.uint_32 & 0555) | S_IFDIR; |
| data->perms.mode = (result.uint_32 & 0666) | S_IFREG; |
| break; |
| |
| case Opt_uid: |
| data->perms.uid = make_kuid(current_user_ns(), result.uint_32); |
| if (!uid_valid(data->perms.uid)) |
| goto unmapped_value; |
| break; |
| case Opt_gid: |
| data->perms.gid = make_kgid(current_user_ns(), result.uint_32); |
| if (!gid_valid(data->perms.gid)) |
| goto unmapped_value; |
| break; |
| |
| default: |
| return -ENOPARAM; |
| } |
| |
| return 0; |
| |
| unmapped_value: |
| return invalf(fc, "%s: unmapped value: %u", param->key, result.uint_32); |
| } |
| |
| /* |
| * Set up the superblock for a mount. |
| */ |
| static int ffs_fs_get_tree(struct fs_context *fc) |
| { |
| struct ffs_sb_fill_data *ctx = fc->fs_private; |
| void *ffs_dev; |
| struct ffs_data *ffs; |
| |
| ENTER(); |
| |
| if (!fc->source) |
| return invalf(fc, "No source specified"); |
| |
| ffs = ffs_data_new(fc->source); |
| if (unlikely(!ffs)) |
| return -ENOMEM; |
| ffs->file_perms = ctx->perms; |
| ffs->no_disconnect = ctx->no_disconnect; |
| |
| ffs->dev_name = kstrdup(fc->source, GFP_KERNEL); |
| if (unlikely(!ffs->dev_name)) { |
| ffs_data_put(ffs); |
| return -ENOMEM; |
| } |
| |
| ffs_dev = ffs_acquire_dev(ffs->dev_name); |
| if (IS_ERR(ffs_dev)) { |
| ffs_data_put(ffs); |
| return PTR_ERR(ffs_dev); |
| } |
| |
| ffs->private_data = ffs_dev; |
| ctx->ffs_data = ffs; |
| return get_tree_nodev(fc, ffs_sb_fill); |
| } |
| |
| static void ffs_fs_free_fc(struct fs_context *fc) |
| { |
| struct ffs_sb_fill_data *ctx = fc->fs_private; |
| |
| if (ctx) { |
| if (ctx->ffs_data) { |
| ffs_release_dev(ctx->ffs_data); |
| ffs_data_put(ctx->ffs_data); |
| } |
| |
| kfree(ctx); |
| } |
| } |
| |
| static const struct fs_context_operations ffs_fs_context_ops = { |
| .free = ffs_fs_free_fc, |
| .parse_param = ffs_fs_parse_param, |
| .get_tree = ffs_fs_get_tree, |
| }; |
| |
| static int ffs_fs_init_fs_context(struct fs_context *fc) |
| { |
| struct ffs_sb_fill_data *ctx; |
| |
| ctx = kzalloc(sizeof(struct ffs_sb_fill_data), GFP_KERNEL); |
| if (!ctx) |
| return -ENOMEM; |
| |
| ctx->perms.mode = S_IFREG | 0600; |
| ctx->perms.uid = GLOBAL_ROOT_UID; |
| ctx->perms.gid = GLOBAL_ROOT_GID; |
| ctx->root_mode = S_IFDIR | 0500; |
| ctx->no_disconnect = false; |
| |
| fc->fs_private = ctx; |
| fc->ops = &ffs_fs_context_ops; |
| return 0; |
| } |
| |
| static void |
| ffs_fs_kill_sb(struct super_block *sb) |
| { |
| ENTER(); |
| |
| kill_litter_super(sb); |
| if (sb->s_fs_info) { |
| ffs_release_dev(sb->s_fs_info); |
| ffs_data_closed(sb->s_fs_info); |
| } |
| } |
| |
| static struct file_system_type ffs_fs_type = { |
| .owner = THIS_MODULE, |
| .name = "functionfs", |
| .init_fs_context = ffs_fs_init_fs_context, |
| .parameters = ffs_fs_fs_parameters, |
| .kill_sb = ffs_fs_kill_sb, |
| }; |
| MODULE_ALIAS_FS("functionfs"); |
| |
| |
| /* Driver's main init/cleanup functions *************************************/ |
| |
| static int functionfs_init(void) |
| { |
| int ret; |
| |
| ENTER(); |
| |
| ret = register_filesystem(&ffs_fs_type); |
| if (likely(!ret)) |
| pr_info("file system registered\n"); |
| else |
| pr_err("failed registering file system (%d)\n", ret); |
| |
| return ret; |
| } |
| |
| static void functionfs_cleanup(void) |
| { |
| ENTER(); |
| |
| pr_info("unloading\n"); |
| unregister_filesystem(&ffs_fs_type); |
| } |
| |
| |
| /* ffs_data and ffs_function construction and destruction code **************/ |
| |
| static void ffs_data_clear(struct ffs_data *ffs); |
| static void ffs_data_reset(struct ffs_data *ffs); |
| |
| static void ffs_data_get(struct ffs_data *ffs) |
| { |
| ENTER(); |
| |
| refcount_inc(&ffs->ref); |
| } |
| |
| static void ffs_data_opened(struct ffs_data *ffs) |
| { |
| ENTER(); |
| |
| refcount_inc(&ffs->ref); |
| if (atomic_add_return(1, &ffs->opened) == 1 && |
| ffs->state == FFS_DEACTIVATED) { |
| ffs->state = FFS_CLOSING; |
| ffs_data_reset(ffs); |
| } |
| } |
| |
| static void ffs_data_put(struct ffs_data *ffs) |
| { |
| ENTER(); |
| |
| if (unlikely(refcount_dec_and_test(&ffs->ref))) { |
| pr_info("%s(): freeing\n", __func__); |
| ffs_data_clear(ffs); |
| BUG_ON(waitqueue_active(&ffs->ev.waitq) || |
| swait_active(&ffs->ep0req_completion.wait) || |
| waitqueue_active(&ffs->wait)); |
| destroy_workqueue(ffs->io_completion_wq); |
| kfree(ffs->dev_name); |
| kfree(ffs); |
| } |
| } |
| |
| static void ffs_data_closed(struct ffs_data *ffs) |
| { |
| ENTER(); |
| |
| if (atomic_dec_and_test(&ffs->opened)) { |
| if (ffs->no_disconnect) { |
| ffs->state = FFS_DEACTIVATED; |
| if (ffs->epfiles) { |
| ffs_epfiles_destroy(ffs->epfiles, |
| ffs->eps_count); |
| ffs->epfiles = NULL; |
| } |
| if (ffs->setup_state == FFS_SETUP_PENDING) |
| __ffs_ep0_stall(ffs); |
| } else { |
| ffs->state = FFS_CLOSING; |
| ffs_data_reset(ffs); |
| } |
| } |
| if (atomic_read(&ffs->opened) < 0) { |
| ffs->state = FFS_CLOSING; |
| ffs_data_reset(ffs); |
| } |
| |
| ffs_data_put(ffs); |
| } |
| |
| static struct ffs_data *ffs_data_new(const char *dev_name) |
| { |
| struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL); |
| if (unlikely(!ffs)) |
| return NULL; |
| |
| ENTER(); |
| |
| ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name); |
| if (!ffs->io_completion_wq) { |
| kfree(ffs); |
| return NULL; |
| } |
| |
| refcount_set(&ffs->ref, 1); |
| atomic_set(&ffs->opened, 0); |
| ffs->state = FFS_READ_DESCRIPTORS; |
| mutex_init(&ffs->mutex); |
| spin_lock_init(&ffs->eps_lock); |
| init_waitqueue_head(&ffs->ev.waitq); |
| init_waitqueue_head(&ffs->wait); |
| init_completion(&ffs->ep0req_completion); |
| |
| /* XXX REVISIT need to update it in some places, or do we? */ |
| ffs->ev.can_stall = 1; |
| |
| return ffs; |
| } |
| |
| static void ffs_data_clear(struct ffs_data *ffs) |
| { |
| ENTER(); |
| |
| ffs_closed(ffs); |
| |
| BUG_ON(ffs->gadget); |
| |
| if (ffs->epfiles) |
| ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count); |
| |
| if (ffs->ffs_eventfd) |
| eventfd_ctx_put(ffs->ffs_eventfd); |
| |
| kfree(ffs->raw_descs_data); |
| kfree(ffs->raw_strings); |
| kfree(ffs->stringtabs); |
| } |
| |
| static void ffs_data_reset(struct ffs_data *ffs) |
| { |
| ENTER(); |
| |
| ffs_data_clear(ffs); |
| |
| ffs->epfiles = NULL; |
| ffs->raw_descs_data = NULL; |
| ffs->raw_descs = NULL; |
| ffs->raw_strings = NULL; |
| ffs->stringtabs = NULL; |
| |
| ffs->raw_descs_length = 0; |
| ffs->fs_descs_count = 0; |
| ffs->hs_descs_count = 0; |
| ffs->ss_descs_count = 0; |
| |
| ffs->strings_count = 0; |
| ffs->interfaces_count = 0; |
| ffs->eps_count = 0; |
| |
| ffs->ev.count = 0; |
| |
| ffs->state = FFS_READ_DESCRIPTORS; |
| ffs->setup_state = FFS_NO_SETUP; |
| ffs->flags = 0; |
| |
| ffs->ms_os_descs_ext_prop_count = 0; |
| ffs->ms_os_descs_ext_prop_name_len = 0; |
| ffs->ms_os_descs_ext_prop_data_len = 0; |
| } |
| |
| |
| static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) |
| { |
| struct usb_gadget_strings **lang; |
| int first_id; |
| |
| ENTER(); |
| |
| if (WARN_ON(ffs->state != FFS_ACTIVE |
| || test_and_set_bit(FFS_FL_BOUND, &ffs->flags))) |
| return -EBADFD; |
| |
| first_id = usb_string_ids_n(cdev, ffs->strings_count); |
| if (unlikely(first_id < 0)) |
| return first_id; |
| |
| ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); |
| if (unlikely(!ffs->ep0req)) |
| return -ENOMEM; |
| ffs->ep0req->complete = ffs_ep0_complete; |
| ffs->ep0req->context = ffs; |
| |
| lang = ffs->stringtabs; |
| if (lang) { |
| for (; *lang; ++lang) { |
| struct usb_string *str = (*lang)->strings; |
| int id = first_id; |
| for (; str->s; ++id, ++str) |
| str->id = id; |
| } |
| } |
| |
| ffs->gadget = cdev->gadget; |
| ffs_data_get(ffs); |
| return 0; |
| } |
| |
| static void functionfs_unbind(struct ffs_data *ffs) |
| { |
| ENTER(); |
| |
| if (!WARN_ON(!ffs->gadget)) { |
| usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req); |
| ffs->ep0req = NULL; |
| ffs->gadget = NULL; |
| clear_bit(FFS_FL_BOUND, &ffs->flags); |
| ffs_data_put(ffs); |
| } |
| } |
| |
| static int ffs_epfiles_create(struct ffs_data *ffs) |
| { |
| struct ffs_epfile *epfile, *epfiles; |
| unsigned i, count; |
| |
| ENTER(); |
| |
| count = ffs->eps_count; |
| epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL); |
| if (!epfiles) |
| return -ENOMEM; |
| |
| epfile = epfiles; |
| for (i = 1; i <= count; ++i, ++epfile) { |
| epfile->ffs = ffs; |
| mutex_init(&epfile->mutex); |
| if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) |
| sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]); |
| else |
| sprintf(epfile->name, "ep%u", i); |
| epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name, |
| epfile, |
| &ffs_epfile_operations); |
| if (unlikely(!epfile->dentry)) { |
| ffs_epfiles_destroy(epfiles, i - 1); |
| return -ENOMEM; |
| } |
| } |
| |
| ffs->epfiles = epfiles; |
| return 0; |
| } |
| |
| static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count) |
| { |
| struct ffs_epfile *epfile = epfiles; |
| |
| ENTER(); |
| |
| for (; count; --count, ++epfile) { |
| BUG_ON(mutex_is_locked(&epfile->mutex)); |
| if (epfile->dentry) { |
| d_delete(epfile->dentry); |
| dput(epfile->dentry); |
| epfile->dentry = NULL; |
| } |
| } |
| |
| kfree(epfiles); |
| } |
| |
| static void ffs_func_eps_disable(struct ffs_function *func) |
| { |
| struct ffs_ep *ep = func->eps; |
| struct ffs_epfile *epfile = func->ffs->epfiles; |
| unsigned count = func->ffs->eps_count; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&func->ffs->eps_lock, flags); |
| while (count--) { |
| /* pending requests get nuked */ |
| if (likely(ep->ep)) |
| usb_ep_disable(ep->ep); |
| ++ep; |
| |
| if (epfile) { |
| epfile->ep = NULL; |
| __ffs_epfile_read_buffer_free(epfile); |
| ++epfile; |
| } |
| } |
| spin_unlock_irqrestore(&func->ffs->eps_lock, flags); |
| } |
| |
| static int ffs_func_eps_enable(struct ffs_function *func) |
| { |
| struct ffs_data *ffs = func->ffs; |
| struct ffs_ep *ep = func->eps; |
| struct ffs_epfile *epfile = ffs->epfiles; |
| unsigned count = ffs->eps_count; |
| unsigned long flags; |
| int ret = 0; |
| |
| spin_lock_irqsave(&func->ffs->eps_lock, flags); |
| while(count--) { |
| ep->ep->driver_data = ep; |
| |
| ret = config_ep_by_speed(func->gadget, &func->function, ep->ep); |
| if (ret) { |
| pr_err("%s: config_ep_by_speed(%s) returned %d\n", |
| __func__, ep->ep->name, ret); |
| break; |
| } |
| |
| ret = usb_ep_enable(ep->ep); |
| if (likely(!ret)) { |
| epfile->ep = ep; |
| epfile->in = usb_endpoint_dir_in(ep->ep->desc); |
| epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc); |
| } else { |
| break; |
| } |
| |
| ++ep; |
| ++epfile; |
| } |
| |
| wake_up_interruptible(&ffs->wait); |
| spin_unlock_irqrestore(&func->ffs->eps_lock, flags); |
| |
| return ret; |
| } |
| |
| |
| /* Parsing and building descriptors and strings *****************************/ |
| |
| /* |
| * This validates if data pointed by data is a valid USB descriptor as |
| * well as record how many interfaces, endpoints and strings are |
| * required by given configuration. Returns address after the |
| * descriptor or NULL if data is invalid. |
| */ |
| |
| enum ffs_entity_type { |
| FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT |
| }; |
| |
| enum ffs_os_desc_type { |
| FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP |
| }; |
| |
| typedef int (*ffs_entity_callback)(enum ffs_entity_type entity, |
| u8 *valuep, |
| struct usb_descriptor_header *desc, |
| void *priv); |
| |
| typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity, |
| struct usb_os_desc_header *h, void *data, |
| unsigned len, void *priv); |
| |
| static int __must_check ffs_do_single_desc(char *data, unsigned len, |
| ffs_entity_callback entity, |
| void *priv, int *current_class) |
| { |
| struct usb_descriptor_header *_ds = (void *)data; |
| u8 length; |
| int ret; |
| |
| ENTER(); |
| |
| /* At least two bytes are required: length and type */ |
| if (len < 2) { |
| pr_vdebug("descriptor too short\n"); |
| return -EINVAL; |
| } |
| |
| /* If we have at least as many bytes as the descriptor takes? */ |
| length = _ds->bLength; |
| if (len < length) { |
| pr_vdebug("descriptor longer then available data\n"); |
| return -EINVAL; |
| } |
| |
| #define __entity_check_INTERFACE(val) 1 |
| #define __entity_check_STRING(val) (val) |
| #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK) |
| #define __entity(type, val) do { \ |
| pr_vdebug("entity " #type "(%02x)\n", (val)); \ |
| if (unlikely(!__entity_check_ ##type(val))) { \ |
| pr_vdebug("invalid entity's value\n"); \ |
| return -EINVAL; \ |
| } \ |
| ret = entity(FFS_ ##type, &val, _ds, priv); \ |
| if (unlikely(ret < 0)) { \ |
| pr_debug("entity " #type "(%02x); ret = %d\n", \ |
| (val), ret); \ |
| return ret; \ |
| } \ |
| } while (0) |
| |
| /* Parse descriptor depending on type. */ |
| switch (_ds->bDescriptorType) { |
| case USB_DT_DEVICE: |
| case USB_DT_CONFIG: |
| case USB_DT_STRING: |
| case USB_DT_DEVICE_QUALIFIER: |
| /* function can't have any of those */ |
| pr_vdebug("descriptor reserved for gadget: %d\n", |
| _ds->bDescriptorType); |
| return -EINVAL; |
| |
| case USB_DT_INTERFACE: { |
| struct usb_interface_descriptor *ds = (void *)_ds; |
| pr_vdebug("interface descriptor\n"); |
| if (length != sizeof *ds) |
| goto inv_length; |
| |
| __entity(INTERFACE, ds->bInterfaceNumber); |
| if (ds->iInterface) |
| __entity(STRING, ds->iInterface); |
| *current_class = ds->bInterfaceClass; |
| } |
| break; |
| |
| case USB_DT_ENDPOINT: { |
| struct usb_endpoint_descriptor *ds = (void *)_ds; |
| pr_vdebug("endpoint descriptor\n"); |
| if (length != USB_DT_ENDPOINT_SIZE && |
| length != USB_DT_ENDPOINT_AUDIO_SIZE) |
| goto inv_length; |
| __entity(ENDPOINT, ds->bEndpointAddress); |
| } |
| break; |
| |
| case USB_TYPE_CLASS | 0x01: |
| if (*current_class == USB_INTERFACE_CLASS_HID) { |
| pr_vdebug("hid descriptor\n"); |
| if (length != sizeof(struct hid_descriptor)) |
| goto inv_length; |
| break; |
| } else if (*current_class == USB_INTERFACE_CLASS_CCID) { |
| pr_vdebug("ccid descriptor\n"); |
| if (length != sizeof(struct ccid_descriptor)) |
| goto inv_length; |
| break; |
| } else { |
| pr_vdebug("unknown descriptor: %d for class %d\n", |
| _ds->bDescriptorType, *current_class); |
| return -EINVAL; |
| } |
| |
| case USB_DT_OTG: |
| if (length != sizeof(struct usb_otg_descriptor)) |
| goto inv_length; |
| break; |
| |
| case USB_DT_INTERFACE_ASSOCIATION: { |
| struct usb_interface_assoc_descriptor *ds = (void *)_ds; |
| pr_vdebug("interface association descriptor\n"); |
| if (length != sizeof *ds) |
| goto inv_length; |
| if (ds->iFunction) |
| __entity(STRING, ds->iFunction); |
| } |
| break; |
| |
| case USB_DT_SS_ENDPOINT_COMP: |
| pr_vdebug("EP SS companion descriptor\n"); |
| if (length != sizeof(struct usb_ss_ep_comp_descriptor)) |
| goto inv_length; |
| break; |
| |
| case USB_DT_OTHER_SPEED_CONFIG: |
| case USB_DT_INTERFACE_POWER: |
| case USB_DT_DEBUG: |
| case USB_DT_SECURITY: |
| case USB_DT_CS_RADIO_CONTROL: |
| /* TODO */ |
| pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType); |
| return -EINVAL; |
| |
| default: |
| /* We should never be here */ |
| pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType); |
| return -EINVAL; |
| |
| inv_length: |
| pr_vdebug("invalid length: %d (descriptor %d)\n", |
| _ds->bLength, _ds->bDescriptorType); |
| return -EINVAL; |
| } |
| |
| #undef __entity |
| #undef __entity_check_DESCRIPTOR |
| #undef __entity_check_INTERFACE |
| #undef __entity_check_STRING |
| #undef __entity_check_ENDPOINT |
| |
| return length; |
| } |
| |
| static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, |
| ffs_entity_callback entity, void *priv) |
| { |
| const unsigned _len = len; |
| unsigned long num = 0; |
| int current_class = -1; |
| |
| ENTER(); |
| |
| for (;;) { |
| int ret; |
| |
| if (num == count) |
| data = NULL; |
| |
| /* Record "descriptor" entity */ |
| ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv); |
| if (unlikely(ret < 0)) { |
| pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n", |
| num, ret); |
| return ret; |
| } |
| |
| if (!data) |
| return _len - len; |
| |
| ret = ffs_do_single_desc(data, len, entity, priv, |
| ¤t_class); |
| if (unlikely(ret < 0)) { |
| pr_debug("%s returns %d\n", __func__, ret); |
| return ret; |
| } |
| |
| len -= ret; |
| data += ret; |
| ++num; |
| } |
| } |
| |
| static int __ffs_data_do_entity(enum ffs_entity_type type, |
| u8 *valuep, struct usb_descriptor_header *desc, |
| void *priv) |
| { |
| struct ffs_desc_helper *helper = priv; |
| struct usb_endpoint_descriptor *d; |
| |
| ENTER(); |
| |
| switch (type) { |
| case FFS_DESCRIPTOR: |
| break; |
| |
| case FFS_INTERFACE: |
| /* |
| * Interfaces are indexed from zero so if we |
| * encountered interface "n" then there are at least |
| * "n+1" interfaces. |
| */ |
| if (*valuep >= helper->interfaces_count) |
| helper->interfaces_count = *valuep + 1; |
| break; |
| |
| case FFS_STRING: |
| /* |
| * Strings are indexed from 1 (0 is reserved |
| * for languages list) |
| */ |
| if (*valuep > helper->ffs->strings_count) |
| helper->ffs->strings_count = *valuep; |
| break; |
| |
| case FFS_ENDPOINT: |
| d = (void *)desc; |
| helper->eps_count++; |
| if (helper->eps_count >= FFS_MAX_EPS_COUNT) |
| return -EINVAL; |
| /* Check if descriptors for any speed were already parsed */ |
| if (!helper->ffs->eps_count && !helper->ffs->interfaces_count) |
| helper->ffs->eps_addrmap[helper->eps_count] = |
| d->bEndpointAddress; |
| else if (helper->ffs->eps_addrmap[helper->eps_count] != |
| d->bEndpointAddress) |
| return -EINVAL; |
| break; |
| } |
| |
| return 0; |
| } |
| |
| static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type, |
| struct usb_os_desc_header *desc) |
| { |
| u16 bcd_version = le16_to_cpu(desc->bcdVersion); |
| u16 w_index = le16_to_cpu(desc->wIndex); |
| |
| if (bcd_version != 1) { |
| pr_vdebug("unsupported os descriptors version: %d", |
| bcd_version); |
| return -EINVAL; |
| } |
| switch (w_index) { |
| case 0x4: |
| *next_type = FFS_OS_DESC_EXT_COMPAT; |
| break; |
| case 0x5: |
| *next_type = FFS_OS_DESC_EXT_PROP; |
| break; |
| default: |
| pr_vdebug("unsupported os descriptor type: %d", w_index); |
| return -EINVAL; |
| } |
| |
| return sizeof(*desc); |
| } |
| |
| /* |
| * Process all extended compatibility/extended property descriptors |
| * of a feature descriptor |
| */ |
| static int __must_check ffs_do_single_os_desc(char *data, unsigned len, |
| enum ffs_os_desc_type type, |
| u16 feature_count, |
| ffs_os_desc_callback entity, |
| void *priv, |
| struct usb_os_desc_header *h) |
| { |
| int ret; |
| const unsigned _len = len; |
| |
| ENTER(); |
| |
| /* loop over all ext compat/ext prop descriptors */ |
| while (feature_count--) { |
| ret = entity(type, h, data, len, priv); |
| if (unlikely(ret < 0)) { |
| pr_debug("bad OS descriptor, type: %d\n", type); |
| return ret; |
| } |
| data += ret; |
| len -= ret; |
| } |
| return _len - len; |
| } |
| |
| /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */ |
| static int __must_check ffs_do_os_descs(unsigned count, |
| char *data, unsigned len, |
| ffs_os_desc_callback entity, void *priv) |
| { |
| const unsigned _len = len; |
| unsigned long num = 0; |
| |
| ENTER(); |
| |
| for (num = 0; num < count; ++num) { |
| int ret; |
| enum ffs_os_desc_type type; |
| u16 feature_count; |
| struct usb_os_desc_header *desc = (void *)data; |
| |
| if (len < sizeof(*desc)) |
| return -EINVAL; |
| |
| /* |
| * Record "descriptor" entity. |
| * Process dwLength, bcdVersion, wIndex, get b/wCount. |
| * Move the data pointer to the beginning of extended |
| * compatibilities proper or extended properties proper |
| * portions of the data |
| */ |
| if (le32_to_cpu(desc->dwLength) > len) |
| return -EINVAL; |
| |
| ret = __ffs_do_os_desc_header(&type, desc); |
| if (unlikely(ret < 0)) { |
| pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n", |
| num, ret); |
| return ret; |
| } |
| /* |
| * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??" |
| */ |
| feature_count = le16_to_cpu(desc->wCount); |
| if (type == FFS_OS_DESC_EXT_COMPAT && |
| (feature_count > 255 || desc->Reserved)) |
| return -EINVAL; |
| len -= ret; |
| data += ret; |
| |
| /* |
| * Process all function/property descriptors |
| * of this Feature Descriptor |
| */ |
| ret = ffs_do_single_os_desc(data, len, type, |
| feature_count, entity, priv, desc); |
| if (unlikely(ret < 0)) { |
| pr_debug("%s returns %d\n", __func__, ret); |
| return ret; |
| } |
| |
| len -= ret; |
| data += ret; |
| } |
| return _len - len; |
| } |
| |
| /* |
| * Validate contents of the buffer from userspace related to OS descriptors. |
| */ |
| static int __ffs_data_do_os_desc(enum ffs_os_desc_type type, |
| struct usb_os_desc_header *h, void *data, |
| unsigned len, void *priv) |
| { |
| struct ffs_data *ffs = priv; |
| u8 length; |
| |
| ENTER(); |
| |
| switch (type) { |
| case FFS_OS_DESC_EXT_COMPAT: { |
| struct usb_ext_compat_desc *d = data; |
| int i; |
| |
| if (len < sizeof(*d) || |
| d->bFirstInterfaceNumber >= ffs->interfaces_count) |
| return -EINVAL; |
| if (d->Reserved1 != 1) { |
| /* |
| * According to the spec, Reserved1 must be set to 1 |
| * but older kernels incorrectly rejected non-zero |
| * values. We fix it here to avoid returning EINVAL |
| * in response to values we used to accept. |
| */ |
| pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n"); |
| d->Reserved1 = 1; |
| } |
| for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i) |
| if (d->Reserved2[i]) |
| return -EINVAL; |
| |
| length = sizeof(struct usb_ext_compat_desc); |
| } |
| break; |
| case FFS_OS_DESC_EXT_PROP: { |
| struct usb_ext_prop_desc *d = data; |
| u32 type, pdl; |
| u16 pnl; |
| |
| if (len < sizeof(*d) || h->interface >= ffs->interfaces_count) |
| return -EINVAL; |
| length = le32_to_cpu(d->dwSize); |
| if (len < length) |
| return -EINVAL; |
| type = le32_to_cpu(d->dwPropertyDataType); |
| if (type < USB_EXT_PROP_UNICODE || |
| type > USB_EXT_PROP_UNICODE_MULTI) { |
| pr_vdebug("unsupported os descriptor property type: %d", |
| type); |
| return -EINVAL; |
| } |
| pnl = le16_to_cpu(d->wPropertyNameLength); |
| if (length < 14 + pnl) { |
| pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n", |
| length, pnl, type); |
| return -EINVAL; |
| } |
| pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl)); |
| if (length != 14 + pnl + pdl) { |
| pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n", |
| length, pnl, pdl, type); |
| return -EINVAL; |
| } |
| ++ffs->ms_os_descs_ext_prop_count; |
| /* property name reported to the host as "WCHAR"s */ |
| ffs->ms_os_descs_ext_prop_name_len += pnl * 2; |
| ffs->ms_os_descs_ext_prop_data_len += pdl; |
| } |
| break; |
| default: |
| pr_vdebug("unknown descriptor: %d\n", type); |
| return -EINVAL; |
| } |
| return length; |
| } |
| |
| static int __ffs_data_got_descs(struct ffs_data *ffs, |
| char *const _data, size_t len) |
| { |
| char *data = _data, *raw_descs; |
| unsigned os_descs_count = 0, counts[3], flags; |
| int ret = -EINVAL, i; |
| struct ffs_desc_helper helper; |
| |
| ENTER(); |
| |
| if (get_unaligned_le32(data + 4) != len) |
| goto error; |
| |
| switch (get_unaligned_le32(data)) { |
| case FUNCTIONFS_DESCRIPTORS_MAGIC: |
| flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC; |
| data += 8; |
| len -= 8; |
| break; |
| case FUNCTIONFS_DESCRIPTORS_MAGIC_V2: |
| flags = get_unaligned_le32(data + 8); |
| ffs->user_flags = flags; |
| if (flags & ~(FUNCTIONFS_HAS_FS_DESC | |
| FUNCTIONFS_HAS_HS_DESC | |
| FUNCTIONFS_HAS_SS_DESC | |
| FUNCTIONFS_HAS_MS_OS_DESC | |
| FUNCTIONFS_VIRTUAL_ADDR | |
| FUNCTIONFS_EVENTFD | |
| FUNCTIONFS_ALL_CTRL_RECIP | |
| FUNCTIONFS_CONFIG0_SETUP)) { |
| ret = -ENOSYS; |
| goto error; |
| } |
| data += 12; |
| len -= 12; |
| break; |
| default: |
| goto error; |
| } |
| |
| if (flags & FUNCTIONFS_EVENTFD) { |
| if (len < 4) |
| goto error; |
| ffs->ffs_eventfd = |
| eventfd_ctx_fdget((int)get_unaligned_le32(data)); |
| if (IS_ERR(ffs->ffs_eventfd)) { |
| ret = PTR_ERR(ffs->ffs_eventfd); |
| ffs->ffs_eventfd = NULL; |
| goto error; |
| } |
| data += 4; |
| len -= 4; |
| } |
| |
| /* Read fs_count, hs_count and ss_count (if present) */ |
| for (i = 0; i < 3; ++i) { |
| if (!(flags & (1 << i))) { |
| counts[i] = 0; |
| } else if (len < 4) { |
| goto error; |
| } else { |
| counts[i] = get_unaligned_le32(data); |
| data += 4; |
| len -= 4; |
| } |
| } |
| if (flags & (1 << i)) { |
| if (len < 4) { |
| goto error; |
| } |
| os_descs_count = get_unaligned_le32(data); |
| data += 4; |
| len -= 4; |
| } |
| |
| /* Read descriptors */ |
| raw_descs = data; |
| helper.ffs = ffs; |
| for (i = 0; i < 3; ++i) { |
| if (!counts[i]) |
| continue; |
| helper.interfaces_count = 0; |
| helper.eps_count = 0; |
| ret = ffs_do_descs(counts[i], data, len, |
| __ffs_data_do_entity, &helper); |
| if (ret < 0) |
| goto error; |
| if (!ffs->eps_count && !ffs->interfaces_count) { |
| ffs->eps_count = helper.eps_count; |
| ffs->interfaces_count = helper.interfaces_count; |
| } else { |
| if (ffs->eps_count != helper.eps_count) { |
| ret = -EINVAL; |
| goto error; |
| } |
| if (ffs->interfaces_count != helper.interfaces_count) { |
| ret = -EINVAL; |
| goto error; |
| } |
| } |
| data += ret; |
| len -= ret; |
| } |
| if (os_descs_count) { |
| ret = ffs_do_os_descs(os_descs_count, data, len, |
| __ffs_data_do_os_desc, ffs); |
| if (ret < 0) |
| goto error; |
| data += ret; |
| len -= ret; |
| } |
| |
| if (raw_descs == data || len) { |
| ret = -EINVAL; |
| goto error; |
| } |
| |
| ffs->raw_descs_data = _data; |
| ffs->raw_descs = raw_descs; |
| ffs->raw_descs_length = data - raw_descs; |
| ffs->fs_descs_count = counts[0]; |
| ffs->hs_descs_count = counts[1]; |
| ffs->ss_descs_count = counts[2]; |
| ffs->ms_os_descs_count = os_descs_count; |
| |
| return 0; |
| |
| error: |
| kfree(_data); |
| return ret; |
| } |
| |
| static int __ffs_data_got_strings(struct ffs_data *ffs, |
| char *const _data, size_t len) |
| { |
| u32 str_count, needed_count, lang_count; |
| struct usb_gadget_strings **stringtabs, *t; |
| const char *data = _data; |
| struct usb_string *s; |
| |
| ENTER(); |
| |
| if (unlikely(len < 16 || |
| get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC || |
| get_unaligned_le32(data + 4) != len)) |
| goto error; |
| str_count = get_unaligned_le32(data + 8); |
| lang_count = get_unaligned_le32(data + 12); |
| |
| /* if one is zero the other must be zero */ |
| if (unlikely(!str_count != !lang_count)) |
| goto error; |
| |
| /* Do we have at least as many strings as descriptors need? */ |
| needed_count = ffs->strings_count; |
| if (unlikely(str_count < needed_count)) |
| goto error; |
| |
| /* |
| * If we don't need any strings just return and free all |
| * memory. |
| */ |
| if (!needed_count) { |
| kfree(_data); |
| return 0; |
| } |
| |
| /* Allocate everything in one chunk so there's less maintenance. */ |
| { |
| unsigned i = 0; |
| vla_group(d); |
| vla_item(d, struct usb_gadget_strings *, stringtabs, |
| lang_count + 1); |
| vla_item(d, struct usb_gadget_strings, stringtab, lang_count); |
| vla_item(d, struct usb_string, strings, |
| lang_count*(needed_count+1)); |
| |
| char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL); |
| |
| if (unlikely(!vlabuf)) { |
| kfree(_data); |
| return -ENOMEM; |
| } |
| |
| /* Initialize the VLA pointers */ |
| stringtabs = vla_ptr(vlabuf, d, stringtabs); |
| t = vla_ptr(vlabuf, d, stringtab); |
| i = lang_count; |
| do { |
| *stringtabs++ = t++; |
| } while (--i); |
| *stringtabs = NULL; |
| |
| /* stringtabs = vlabuf = d_stringtabs for later kfree */ |
| stringtabs = vla_ptr(vlabuf, d, stringtabs); |
| t = vla_ptr(vlabuf, d, stringtab); |
| s = vla_ptr(vlabuf, d, strings); |
| } |
| |
| /* For each language */ |
| data += 16; |
| len -= 16; |
| |
| do { /* lang_count > 0 so we can use do-while */ |
| unsigned needed = needed_count; |
| |
| if (unlikely(len < 3)) |
| goto error_free; |
| t->language = get_unaligned_le16(data); |
| t->strings = s; |
| ++t; |
| |
| data += 2; |
| len -= 2; |
| |
| /* For each string */ |
| do { /* str_count > 0 so we can use do-while */ |
| size_t length = strnlen(data, len); |
| |
| if (unlikely(length == len)) |
| goto error_free; |
| |
| /* |
| * User may provide more strings then we need, |
| * if that's the case we simply ignore the |
| * rest |
| */ |
| if (likely(needed)) { |
| /* |
| * s->id will be set while adding |
| * function to configuration so for |
| * now just leave garbage here. |
| */ |
| s->s = data; |
| --needed; |
| ++s; |
| } |
| |
| data += length + 1; |
| len -= length + 1; |
| } while (--str_count); |
| |
| s->id = 0; /* terminator */ |
| s->s = NULL; |
| ++s; |
| |
| } while (--lang_count); |
| |
| /* Some garbage left? */ |
| if (unlikely(len)) |
| goto error_free; |
| |
| /* Done! */ |
| ffs->stringtabs = stringtabs; |
| ffs->raw_strings = _data; |
| |
| return 0; |
| |
| error_free: |
| kfree(stringtabs); |
| error: |
| kfree(_data); |
| return -EINVAL; |
| } |
| |
| |
| /* Events handling and management *******************************************/ |
| |
| static void __ffs_event_add(struct ffs_data *ffs, |
| enum usb_functionfs_event_type type) |
| { |
| enum usb_functionfs_event_type rem_type1, rem_type2 = type; |
| int neg = 0; |
| |
| /* |
| * Abort any unhandled setup |
| * |
| * We do not need to worry about some cmpxchg() changing value |
| * of ffs->setup_state without holding the lock because when |
| * state is FFS_SETUP_PENDING cmpxchg() in several places in |
| * the source does nothing. |
| */ |
| if (ffs->setup_state == FFS_SETUP_PENDING) |
| ffs->setup_state = FFS_SETUP_CANCELLED; |
| |
| /* |
| * Logic of this function guarantees that there are at most four pending |
| * evens on ffs->ev.types queue. This is important because the queue |
| * has space for four elements only and __ffs_ep0_read_events function |
| * depends on that limit as well. If more event types are added, those |
| * limits have to be revisited or guaranteed to still hold. |
| */ |
| switch (type) { |
| case FUNCTIONFS_RESUME: |
| rem_type2 = FUNCTIONFS_SUSPEND; |
| fallthrough; |
| case FUNCTIONFS_SUSPEND: |
| case FUNCTIONFS_SETUP: |
| rem_type1 = type; |
| /* Discard all similar events */ |
| break; |
| |
| case FUNCTIONFS_BIND: |
| case FUNCTIONFS_UNBIND: |
| case FUNCTIONFS_DISABLE: |
| case FUNCTIONFS_ENABLE: |
| /* Discard everything other then power management. */ |
| rem_type1 = FUNCTIONFS_SUSPEND; |
| rem_type2 = FUNCTIONFS_RESUME; |
| neg = 1; |
| break; |
| |
| default: |
| WARN(1, "%d: unknown event, this should not happen\n", type); |
| return; |
| } |
| |
| { |
| u8 *ev = ffs->ev.types, *out = ev; |
| unsigned n = ffs->ev.count; |
| for (; n; --n, ++ev) |
| if ((*ev == rem_type1 || *ev == rem_type2) == neg) |
| *out++ = *ev; |
| else |
| pr_vdebug("purging event %d\n", *ev); |
| ffs->ev.count = out - ffs->ev.types; |
| } |
| |
| pr_vdebug("adding event %d\n", type); |
| ffs->ev.types[ffs->ev.count++] = type; |
| wake_up_locked(&ffs->ev.waitq); |
| if (ffs->ffs_eventfd) |
| eventfd_signal(ffs->ffs_eventfd, 1); |
| } |
| |
| static void ffs_event_add(struct ffs_data *ffs, |
| enum usb_functionfs_event_type type) |
| { |
| unsigned long flags; |
| spin_lock_irqsave(&ffs->ev.waitq.lock, flags); |
| __ffs_event_add(ffs, type); |
| spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); |
| } |
| |
| /* Bind/unbind USB function hooks *******************************************/ |
| |
| static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address) |
| { |
| int i; |
| |
| for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i) |
| if (ffs->eps_addrmap[i] == endpoint_address) |
| return i; |
| return -ENOENT; |
| } |
| |
| static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep, |
| struct usb_descriptor_header *desc, |
| void *priv) |
| { |
| struct usb_endpoint_descriptor *ds = (void *)desc; |
| struct ffs_function *func = priv; |
| struct ffs_ep *ffs_ep; |
| unsigned ep_desc_id; |
| int idx; |
| static const char *speed_names[] = { "full", "high", "super" }; |
| |
| if (type != FFS_DESCRIPTOR) |
| return 0; |
| |
| /* |
| * If ss_descriptors is not NULL, we are reading super speed |
| * descriptors; if hs_descriptors is not NULL, we are reading high |
| * speed descriptors; otherwise, we are reading full speed |
| * descriptors. |
| */ |
| if (func->function.ss_descriptors) { |
| ep_desc_id = 2; |
| func->function.ss_descriptors[(long)valuep] = desc; |
| } else if (func->function.hs_descriptors) { |
| ep_desc_id = 1; |
| func->function.hs_descriptors[(long)valuep] = desc; |
| } else { |
| ep_desc_id = 0; |
| func->function.fs_descriptors[(long)valuep] = desc; |
| } |
| |
| if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) |
| return 0; |
| |
| idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1; |
| if (idx < 0) |
| return idx; |
| |
| ffs_ep = func->eps + idx; |
| |
| if (unlikely(ffs_ep->descs[ep_desc_id])) { |
| pr_err("two %sspeed descriptors for EP %d\n", |
| speed_names[ep_desc_id], |
| ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); |
| return -EINVAL; |
| } |
| ffs_ep->descs[ep_desc_id] = ds; |
| |
| ffs_dump_mem(": Original ep desc", ds, ds->bLength); |
| if (ffs_ep->ep) { |
| ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress; |
| if (!ds->wMaxPacketSize) |
| ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize; |
| } else { |
| struct usb_request *req; |
| struct usb_ep *ep; |
| u8 bEndpointAddress; |
| u16 wMaxPacketSize; |
| |
| /* |
| * We back up bEndpointAddress because autoconfig overwrites |
| * it with physical endpoint address. |
| */ |
| bEndpointAddress = ds->bEndpointAddress; |
| /* |
| * We back up wMaxPacketSize because autoconfig treats |
| * endpoint descriptors as if they were full speed. |
| */ |
| wMaxPacketSize = ds->wMaxPacketSize; |
| pr_vdebug("autoconfig\n"); |
| ep = usb_ep_autoconfig(func->gadget, ds); |
| if (unlikely(!ep)) |
| return -ENOTSUPP; |
| ep->driver_data = func->eps + idx; |
| |
| req = usb_ep_alloc_request(ep, GFP_KERNEL); |
| if (unlikely(!req)) |
| return -ENOMEM; |
| |
| ffs_ep->ep = ep; |
| ffs_ep->req = req; |
| func->eps_revmap[ds->bEndpointAddress & |
| USB_ENDPOINT_NUMBER_MASK] = idx + 1; |
| /* |
| * If we use virtual address mapping, we restore |
| * original bEndpointAddress value. |
| */ |
| if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) |
| ds->bEndpointAddress = bEndpointAddress; |
| /* |
| * Restore wMaxPacketSize which was potentially |
| * overwritten by autoconfig. |
| */ |
| ds->wMaxPacketSize = wMaxPacketSize; |
| } |
| ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength); |
| |
| return 0; |
| } |
| |
| static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep, |
| struct usb_descriptor_header *desc, |
| void *priv) |
| { |
| struct ffs_function *func = priv; |
| unsigned idx; |
| u8 newValue; |
| |
| switch (type) { |
| default: |
| case FFS_DESCRIPTOR: |
| /* Handled in previous pass by __ffs_func_bind_do_descs() */ |
| return 0; |
| |
| case FFS_INTERFACE: |
| idx = *valuep; |
| if (func->interfaces_nums[idx] < 0) { |
| int id = usb_interface_id(func->conf, &func->function); |
| if (unlikely(id < 0)) |
| return id; |
| func->interfaces_nums[idx] = id; |
| } |
| newValue = func->interfaces_nums[idx]; |
| break; |
| |
| case FFS_STRING: |
| /* String' IDs are allocated when fsf_data is bound to cdev */ |
| newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id; |
| break; |
| |
| case FFS_ENDPOINT: |
| /* |
| * USB_DT_ENDPOINT are handled in |
| * __ffs_func_bind_do_descs(). |
| */ |
| if (desc->bDescriptorType == USB_DT_ENDPOINT) |
| return 0; |
| |
| idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1; |
| if (unlikely(!func->eps[idx].ep)) |
| return -EINVAL; |
| |
| { |
| struct usb_endpoint_descriptor **descs; |
| descs = func->eps[idx].descs; |
| newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress; |
| } |
| break; |
| } |
| |
| pr_vdebug("%02x -> %02x\n", *valuep, newValue); |
| *valuep = newValue; |
| return 0; |
| } |
| |
| static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type, |
| struct usb_os_desc_header *h, void *data, |
| unsigned len, void *priv) |
| { |
| struct ffs_function *func = priv; |
| u8 length = 0; |
| |
| switch (type) { |
| case FFS_OS_DESC_EXT_COMPAT: { |
| struct usb_ext_compat_desc *desc = data; |
| struct usb_os_desc_table *t; |
| |
| t = &func->function.os_desc_table[desc->bFirstInterfaceNumber]; |
| t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber]; |
| memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID, |
| ARRAY_SIZE(desc->CompatibleID) + |
| ARRAY_SIZE(desc->SubCompatibleID)); |
| length = sizeof(*desc); |
| } |
| break; |
| case FFS_OS_DESC_EXT_PROP: { |
| struct usb_ext_prop_desc *desc = data; |
| struct usb_os_desc_table *t; |
| struct usb_os_desc_ext_prop *ext_prop; |
| char *ext_prop_name; |
| char *ext_prop_data; |
| |
| t = &func->function.os_desc_table[h->interface]; |
| t->if_id = func->interfaces_nums[h->interface]; |
| |
| ext_prop = func->ffs->ms_os_descs_ext_prop_avail; |
| func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop); |
| |
| ext_prop->type = le32_to_cpu(desc->dwPropertyDataType); |
| ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength); |
| ext_prop->data_len = le32_to_cpu(*(__le32 *) |
| usb_ext_prop_data_len_ptr(data, ext_prop->name_len)); |
| length = ext_prop->name_len + ext_prop->data_len + 14; |
| |
| ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail; |
| func->ffs->ms_os_descs_ext_prop_name_avail += |
| ext_prop->name_len; |
| |
| ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail; |
| func->ffs->ms_os_descs_ext_prop_data_avail += |
| ext_prop->data_len; |
| memcpy(ext_prop_data, |
| usb_ext_prop_data_ptr(data, ext_prop->name_len), |
| ext_prop->data_len); |
| /* unicode data reported to the host as "WCHAR"s */ |
| switch (ext_prop->type) { |
| case USB_EXT_PROP_UNICODE: |
| case USB_EXT_PROP_UNICODE_ENV: |
| case USB_EXT_PROP_UNICODE_LINK: |
| case USB_EXT_PROP_UNICODE_MULTI: |
| ext_prop->data_len *= 2; |
| break; |
| } |
| ext_prop->data = ext_prop_data; |
| |
| memcpy(ext_prop_name, usb_ext_prop_name_ptr(data), |
| ext_prop->name_len); |
| /* property name reported to the host as "WCHAR"s */ |
| ext_prop->name_len *= 2; |
| ext_prop->name = ext_prop_name; |
| |
| t->os_desc->ext_prop_len += |
| ext_prop->name_len + ext_prop->data_len + 14; |
| ++t->os_desc->ext_prop_count; |
| list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop); |
| } |
| break; |
| default: |
| pr_vdebug("unknown descriptor: %d\n", type); |
| } |
| |
| return length; |
| } |
| |
| static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, |
| struct usb_configuration *c) |
| { |
| struct ffs_function *func = ffs_func_from_usb(f); |
| struct f_fs_opts *ffs_opts = |
| container_of(f->fi, struct f_fs_opts, func_inst); |
| int ret; |
| |
| ENTER(); |
| |
| /* |
| * Legacy gadget triggers binding in functionfs_ready_callback, |
| * which already uses locking; taking the same lock here would |
| * cause a deadlock. |
| * |
| * Configfs-enabled gadgets however do need ffs_dev_lock. |
| */ |
| if (!ffs_opts->no_configfs) |
| ffs_dev_lock(); |
| ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV; |
| func->ffs = ffs_opts->dev->ffs_data; |
| if (!ffs_opts->no_configfs) |
| ffs_dev_unlock(); |
| if (ret) |
| return ERR_PTR(ret); |
| |
| func->conf = c; |
| func->gadget = c->cdev->gadget; |
| |
| /* |
| * in drivers/usb/gadget/configfs.c:configfs_composite_bind() |
| * configurations are bound in sequence with list_for_each_entry, |
| * in each configuration its functions are bound in sequence |
| * with list_for_each_entry, so we assume no race condition |
| * with regard to ffs_opts->bound access |
| */ |
| if (!ffs_opts->refcnt) { |
| ret = functionfs_bind(func->ffs, c->cdev); |
| if (ret) |
| return ERR_PTR(ret); |
| } |
| ffs_opts->refcnt++; |
| func->function.strings = func->ffs->stringtabs; |
| |
| return ffs_opts; |
| } |
| |
| static int _ffs_func_bind(struct usb_configuration *c, |
| struct usb_function *f) |
| { |
| struct ffs_function *func = ffs_func_from_usb(f); |
| struct ffs_data *ffs = func->ffs; |
| |
| const int full = !!func->ffs->fs_descs_count; |
| const int high = !!func->ffs->hs_descs_count; |
| const int super = !!func->ffs->ss_descs_count; |
| |
| int fs_len, hs_len, ss_len, ret, i; |
| struct ffs_ep *eps_ptr; |
| |
| /* Make it a single chunk, less management later on */ |
| vla_group(d); |
| vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count); |
| vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs, |
| full ? ffs->fs_descs_count + 1 : 0); |
| vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs, |
| high ? ffs->hs_descs_count + 1 : 0); |
| vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs, |
| super ? ffs->ss_descs_count + 1 : 0); |
| vla_item_with_sz(d, short, inums, ffs->interfaces_count); |
| vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table, |
| c->cdev->use_os_string ? ffs->interfaces_count : 0); |
| vla_item_with_sz(d, char[16], ext_compat, |
| c->cdev->use_os_string ? ffs->interfaces_count : 0); |
| vla_item_with_sz(d, struct usb_os_desc, os_desc, |
| c->cdev->use_os_string ? ffs->interfaces_count : 0); |
| vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop, |
| ffs->ms_os_descs_ext_prop_count); |
| vla_item_with_sz(d, char, ext_prop_name, |
| ffs->ms_os_descs_ext_prop_name_len); |
| vla_item_with_sz(d, char, ext_prop_data, |
| ffs->ms_os_descs_ext_prop_data_len); |
| vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length); |
| char *vlabuf; |
| |
| ENTER(); |
| |
| /* Has descriptors only for speeds gadget does not support */ |
| if (unlikely(!(full | high | super))) |
| return -ENOTSUPP; |
| |
| /* Allocate a single chunk, less management later on */ |
| vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL); |
| if (unlikely(!vlabuf)) |
| return -ENOMEM; |
| |
| ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop); |
| ffs->ms_os_descs_ext_prop_name_avail = |
| vla_ptr(vlabuf, d, ext_prop_name); |
| ffs->ms_os_descs_ext_prop_data_avail = |
| vla_ptr(vlabuf, d, ext_prop_data); |
| |
| /* Copy descriptors */ |
| memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs, |
| ffs->raw_descs_length); |
| |
| memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz); |
| eps_ptr = vla_ptr(vlabuf, d, eps); |
| for (i = 0; i < ffs->eps_count; i++) |
| eps_ptr[i].num = -1; |
| |
| /* Save pointers |
| * d_eps == vlabuf, func->eps used to kfree vlabuf later |
| */ |
| func->eps = vla_ptr(vlabuf, d, eps); |
| func->interfaces_nums = vla_ptr(vlabuf, d, inums); |
| |
| /* |
| * Go through all the endpoint descriptors and allocate |
| * endpoints first, so that later we can rewrite the endpoint |
| * numbers without worrying that it may be described later on. |
| */ |
| if (likely(full)) { |
| func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs); |
| fs_len = ffs_do_descs(ffs->fs_descs_count, |
| vla_ptr(vlabuf, d, raw_descs), |
| d_raw_descs__sz, |
| __ffs_func_bind_do_descs, func); |
| if (unlikely(fs_len < 0)) { |
| ret = fs_len; |
| goto error; |
| } |
| } else { |
| fs_len = 0; |
| } |
| |
| if (likely(high)) { |
| func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs); |
| hs_len = ffs_do_descs(ffs->hs_descs_count, |
| vla_ptr(vlabuf, d, raw_descs) + fs_len, |
| d_raw_descs__sz - fs_len, |
| __ffs_func_bind_do_descs, func); |
| if (unlikely(hs_len < 0)) { |
| ret = hs_len; |
| goto error; |
| } |
| } else { |
| hs_len = 0; |
| } |
| |
| if (likely(super)) { |
| func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs); |
| ss_len = ffs_do_descs(ffs->ss_descs_count, |
| vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len, |
| d_raw_descs__sz - fs_len - hs_len, |
| __ffs_func_bind_do_descs, func); |
| if (unlikely(ss_len < 0)) { |
| ret = ss_len; |
| goto error; |
| } |
| } else { |
| ss_len = 0; |
| } |
| |
| /* |
| * Now handle interface numbers allocation and interface and |
| * endpoint numbers rewriting. We can do that in one go |
| * now. |
| */ |
| ret = ffs_do_descs(ffs->fs_descs_count + |
| (high ? ffs->hs_descs_count : 0) + |
| (super ? ffs->ss_descs_count : 0), |
| vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz, |
| __ffs_func_bind_do_nums, func); |
| if (unlikely(ret < 0)) |
| goto error; |
| |
| func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table); |
| if (c->cdev->use_os_string) { |
| for (i = 0; i < ffs->interfaces_count; ++i) { |
| struct usb_os_desc *desc; |
| |
| desc = func->function.os_desc_table[i].os_desc = |
| vla_ptr(vlabuf, d, os_desc) + |
| i * sizeof(struct usb_os_desc); |
| desc->ext_compat_id = |
| vla_ptr(vlabuf, d, ext_compat) + i * 16; |
| INIT_LIST_HEAD(&desc->ext_prop); |
| } |
| ret = ffs_do_os_descs(ffs->ms_os_descs_count, |
| vla_ptr(vlabuf, d, raw_descs) + |
| fs_len + hs_len + ss_len, |
| d_raw_descs__sz - fs_len - hs_len - |
| ss_len, |
| __ffs_func_bind_do_os_desc, func); |
| if (unlikely(ret < 0)) |
| goto error; |
| } |
| func->function.os_desc_n = |
| c->cdev->use_os_string ? ffs->interfaces_count : 0; |
| |
| /* And we're done */ |
| ffs_event_add(ffs, FUNCTIONFS_BIND); |
| return 0; |
| |
| error: |
| /* XXX Do we need to release all claimed endpoints here? */ |
| return ret; |
| } |
| |
| static int ffs_func_bind(struct usb_configuration *c, |
| struct usb_function *f) |
| { |
| struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c); |
| struct ffs_function *func = ffs_func_from_usb(f); |
| int ret; |
| |
| if (IS_ERR(ffs_opts)) |
| return PTR_ERR(ffs_opts); |
| |
| ret = _ffs_func_bind(c, f); |
| if (ret && !--ffs_opts->refcnt) |
| functionfs_unbind(func->ffs); |
| |
| return ret; |
| } |
| |
| |
| /* Other USB function hooks *************************************************/ |
| |
| static void ffs_reset_work(struct work_struct *work) |
| { |
| struct ffs_data *ffs = container_of(work, |
| struct ffs_data, reset_work); |
| ffs_data_reset(ffs); |
| } |
| |
| static int ffs_func_set_alt(struct usb_function *f, |
| unsigned interface, unsigned alt) |
| { |
| struct ffs_function *func = ffs_func_from_usb(f); |
| struct ffs_data *ffs = func->ffs; |
| int ret = 0, intf; |
| |
| if (alt != (unsigned)-1) { |
| intf = ffs_func_revmap_intf(func, interface); |
| if (unlikely(intf < 0)) |
| return intf; |
| } |
| |
| if (ffs->func) |
| ffs_func_eps_disable(ffs->func); |
| |
| if (ffs->state == FFS_DEACTIVATED) { |
| ffs->state = FFS_CLOSING; |
| INIT_WORK(&ffs->reset_work, ffs_reset_work); |
| schedule_work(&ffs->reset_work); |
| return -ENODEV; |
| } |
| |
| if (ffs->state != FFS_ACTIVE) |
| return -ENODEV; |
| |
| if (alt == (unsigned)-1) { |
| ffs->func = NULL; |
| ffs_event_add(ffs, FUNCTIONFS_DISABLE); |
| return 0; |
| } |
| |
| ffs->func = func; |
| ret = ffs_func_eps_enable(func); |
| if (likely(ret >= 0)) |
| ffs_event_add(ffs, FUNCTIONFS_ENABLE); |
| return ret; |
| } |
| |
| static void ffs_func_disable(struct usb_function *f) |
| { |
| ffs_func_set_alt(f, 0, (unsigned)-1); |
| } |
| |
| static int ffs_func_setup(struct usb_function *f, |
| const struct usb_ctrlrequest *creq) |
| { |
| struct ffs_function *func = ffs_func_from_usb(f); |
| struct ffs_data *ffs = func->ffs; |
| unsigned long flags; |
| int ret; |
| |
| ENTER(); |
| |
| pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType); |
| pr_vdebug("creq->bRequest = %02x\n", creq->bRequest); |
| pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue)); |
| pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex)); |
| pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength)); |
| |
| /* |
| * Most requests directed to interface go through here |
| * (notable exceptions are set/get interface) so we need to |
| * handle them. All other either handled by composite or |
| * passed to usb_configuration->setup() (if one is set). No |
| * matter, we will handle requests directed to endpoint here |
| * as well (as it's straightforward). Other request recipient |
| * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP |
| * is being used. |
| */ |
| if (ffs->state != FFS_ACTIVE) |
| return -ENODEV; |
| |
| switch (creq->bRequestType & USB_RECIP_MASK) { |
| case USB_RECIP_INTERFACE: |
| ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex)); |
| if (unlikely(ret < 0)) |
| return ret; |
| break; |
| |
| case USB_RECIP_ENDPOINT: |
| ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex)); |
| if (unlikely(ret < 0)) |
| return ret; |
| if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) |
| ret = func->ffs->eps_addrmap[ret]; |
| break; |
| |
| default: |
| if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP) |
| ret = le16_to_cpu(creq->wIndex); |
| else |
| return -EOPNOTSUPP; |
| } |
| |
| spin_lock_irqsave(&ffs->ev.waitq.lock, flags); |
| ffs->ev.setup = *creq; |
| ffs->ev.setup.wIndex = cpu_to_le16(ret); |
| __ffs_event_add(ffs, FUNCTIONFS_SETUP); |
| spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); |
| |
| return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0; |
| } |
| |
| static bool ffs_func_req_match(struct usb_function *f, |
| const struct usb_ctrlrequest *creq, |
| bool config0) |
| { |
| struct ffs_function *func = ffs_func_from_usb(f); |
| |
| if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP)) |
| return false; |
| |
| switch (creq->bRequestType & USB_RECIP_MASK) { |
| case USB_RECIP_INTERFACE: |
| return (ffs_func_revmap_intf(func, |
| le16_to_cpu(creq->wIndex)) >= 0); |
| case USB_RECIP_ENDPOINT: |
| return (ffs_func_revmap_ep(func, |
| le16_to_cpu(creq->wIndex)) >= 0); |
| default: |
| return (bool) (func->ffs->user_flags & |
| FUNCTIONFS_ALL_CTRL_RECIP); |
| } |
| } |
| |
| static void ffs_func_suspend(struct usb_function *f) |
| { |
| ENTER(); |
| ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND); |
| } |
| |
| static void ffs_func_resume(struct usb_function *f) |
| { |
| ENTER(); |
| ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME); |
| } |
| |
| |
| /* Endpoint and interface numbers reverse mapping ***************************/ |
| |
| static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) |
| { |
| num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK]; |
| return num ? num : -EDOM; |
| } |
| |
| static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) |
| { |
| short *nums = func->interfaces_nums; |
| unsigned count = func->ffs->interfaces_count; |
| |
| for (; count; --count, ++nums) { |
| if (*nums >= 0 && *nums == intf) |
| return nums - func->interfaces_nums; |
| } |
| |
| return -EDOM; |
| } |
| |
| |
| /* Devices management *******************************************************/ |
| |
| static LIST_HEAD(ffs_devices); |
| |
| static struct ffs_dev *_ffs_do_find_dev(const char *name) |
| { |
| struct ffs_dev *dev; |
| |
| if (!name) |
| return NULL; |
| |
| list_for_each_entry(dev, &ffs_devices, entry) { |
| if (strcmp(dev->name, name) == 0) |
| return dev; |
| } |
| |
| return NULL; |
| } |
| |
| /* |
| * ffs_lock must be taken by the caller of this function |
| */ |
| static struct ffs_dev *_ffs_get_single_dev(void) |
| { |
| struct ffs_dev *dev; |
| |
| if (list_is_singular(&ffs_devices)) { |
| dev = list_first_entry(&ffs_devices, struct ffs_dev, entry); |
| if (dev->single) |
| return dev; |
| } |
| |
| return NULL; |
| } |
| |
| /* |
| * ffs_lock must be taken by the caller of this function |
| */ |
| static struct ffs_dev *_ffs_find_dev(const char *name) |
| { |
| struct ffs_dev *dev; |
| |
| dev = _ffs_get_single_dev(); |
| if (dev) |
| return dev; |
| |
| return _ffs_do_find_dev(name); |
| } |
| |
| /* Configfs support *********************************************************/ |
| |
| static inline struct f_fs_opts *to_ffs_opts(struct config_item *item) |
| { |
| return container_of(to_config_group(item), struct f_fs_opts, |
| func_inst.group); |
| } |
| |
| static void ffs_attr_release(struct config_item *item) |
| { |
| struct f_fs_opts *opts = to_ffs_opts(item); |
| |
| usb_put_function_instance(&opts->func_inst); |
| } |
| |
| static struct configfs_item_operations ffs_item_ops = { |
| .release = ffs_attr_release, |
| }; |
| |
| static const struct config_item_type ffs_func_type = { |
| .ct_item_ops = &ffs_item_ops, |
| .ct_owner = THIS_MODULE, |
| }; |
| |
| |
| /* Function registration interface ******************************************/ |
| |
| static void ffs_free_inst(struct usb_function_instance *f) |
| { |
| struct f_fs_opts *opts; |
| |
| opts = to_f_fs_opts(f); |
| ffs_dev_lock(); |
| _ffs_free_dev(opts->dev); |
| ffs_dev_unlock(); |
| kfree(opts); |
| } |
| |
| static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name) |
| { |
| if (strlen(name) >= sizeof_field(struct ffs_dev, name)) |
| return -ENAMETOOLONG; |
| return ffs_name_dev(to_f_fs_opts(fi)->dev, name); |
| } |
| |
| static struct usb_function_instance *ffs_alloc_inst(void) |
| { |
| struct f_fs_opts *opts; |
| struct ffs_dev *dev; |
| |
| opts = kzalloc(sizeof(*opts), GFP_KERNEL); |
| if (!opts) |
| return ERR_PTR(-ENOMEM); |
| |
| opts->func_inst.set_inst_name = ffs_set_inst_name; |
| opts->func_inst.free_func_inst = ffs_free_inst; |
| ffs_dev_lock(); |
| dev = _ffs_alloc_dev(); |
| ffs_dev_unlock(); |
| if (IS_ERR(dev)) { |
| kfree(opts); |
| return ERR_CAST(dev); |
| } |
| opts->dev = dev; |
| dev->opts = opts; |
| |
| config_group_init_type_name(&opts->func_inst.group, "", |
| &ffs_func_type); |
| return &opts->func_inst; |
| } |
| |
| static void ffs_free(struct usb_function *f) |
| { |
| kfree(ffs_func_from_usb(f)); |
| } |
| |
| static void ffs_func_unbind(struct usb_configuration *c, |
| struct usb_function *f) |
| { |
| struct ffs_function *func = ffs_func_from_usb(f); |
| struct ffs_data *ffs = func->ffs; |
| struct f_fs_opts *opts = |
| container_of(f->fi, struct f_fs_opts, func_inst); |
| struct ffs_ep *ep = func->eps; |
| unsigned count = ffs->eps_count; |
| unsigned long flags; |
| |
| ENTER(); |
| if (ffs->func == func) { |
| ffs_func_eps_disable(func); |
| ffs->func = NULL; |
| } |
| |
| if (!--opts->refcnt) |
| functionfs_unbind(ffs); |
| |
| /* cleanup after autoconfig */ |
| spin_lock_irqsave(&func->ffs->eps_lock, flags); |
| while (count--) { |
| if (ep->ep && ep->req) |
| usb_ep_free_request(ep->ep, ep->req); |
| ep->req = NULL; |
| ++ep; |
| } |
| spin_unlock_irqrestore(&func->ffs->eps_lock, flags); |
| kfree(func->eps); |
| func->eps = NULL; |
| /* |
| * eps, descriptors and interfaces_nums are allocated in the |
| * same chunk so only one free is required. |
| */ |
| func->function.fs_descriptors = NULL; |
| func->function.hs_descriptors = NULL; |
| func->function.ss_descriptors = NULL; |
| func->interfaces_nums = NULL; |
| |
| ffs_event_add(ffs, FUNCTIONFS_UNBIND); |
| } |
| |
| static struct usb_function *ffs_alloc(struct usb_function_instance *fi) |
| { |
| struct ffs_function *func; |
| |
| ENTER(); |
| |
| func = kzalloc(sizeof(*func), GFP_KERNEL); |
| if (unlikely(!func)) |
| return ERR_PTR(-ENOMEM); |
| |
| func->function.name = "Function FS Gadget"; |
| |
| func->function.bind = ffs_func_bind; |
| func->function.unbind = ffs_func_unbind; |
| func->function.set_alt = ffs_func_set_alt; |
| func->function.disable = ffs_func_disable; |
| func->function.setup = ffs_func_setup; |
| func->function.req_match = ffs_func_req_match; |
| func->function.suspend = ffs_func_suspend; |
| func->function.resume = ffs_func_resume; |
| func->function.free_func = ffs_free; |
| |
| return &func->function; |
| } |
| |
| /* |
| * ffs_lock must be taken by the caller of this function |
| */ |
| static struct ffs_dev *_ffs_alloc_dev(void) |
| { |
| struct ffs_dev *dev; |
| int ret; |
| |
| if (_ffs_get_single_dev()) |
| return ERR_PTR(-EBUSY); |
| |
| dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
| if (!dev) |
| return ERR_PTR(-ENOMEM); |
| |
| if (list_empty(&ffs_devices)) { |
| ret = functionfs_init(); |
| if (ret) { |
| kfree(dev); |
| return ERR_PTR(ret); |
| } |
| } |
| |
| list_add(&dev->entry, &ffs_devices); |
| |
| return dev; |
| } |
| |
| int ffs_name_dev(struct ffs_dev *dev, const char *name) |
| { |
| struct ffs_dev *existing; |
| int ret = 0; |
| |
| ffs_dev_lock(); |
| |
| existing = _ffs_do_find_dev(name); |
| if (!existing) |
| strlcpy(dev->name, name, ARRAY_SIZE(dev->name)); |
| else if (existing != dev) |
| ret = -EBUSY; |
| |
| ffs_dev_unlock(); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(ffs_name_dev); |
| |
| int ffs_single_dev(struct ffs_dev *dev) |
| { |
| int ret; |
| |
| ret = 0; |
| ffs_dev_lock(); |
| |
| if (!list_is_singular(&ffs_devices)) |
| ret = -EBUSY; |
| else |
| dev->single = true; |
| |
| ffs_dev_unlock(); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(ffs_single_dev); |
| |
| /* |
| * ffs_lock must be taken by the caller of this function |
| */ |
| static void _ffs_free_dev(struct ffs_dev *dev) |
| { |
| list_del(&dev->entry); |
| |
| /* Clear the private_data pointer to stop incorrect dev access */ |
| if (dev->ffs_data) |
| dev->ffs_data->private_data = NULL; |
| |
| kfree(dev); |
| if (list_empty(&ffs_devices)) |
| functionfs_cleanup(); |
| } |
| |
| static void *ffs_acquire_dev(const char *dev_name) |
| { |
| struct ffs_dev *ffs_dev; |
| |
| ENTER(); |
| ffs_dev_lock(); |
| |
| ffs_dev = _ffs_find_dev(dev_name); |
| if (!ffs_dev) |
| ffs_dev = ERR_PTR(-ENOENT); |
| else if (ffs_dev->mounted) |
| ffs_dev = ERR_PTR(-EBUSY); |
| else if (ffs_dev->ffs_acquire_dev_callback && |
| ffs_dev->ffs_acquire_dev_callback(ffs_dev)) |
| ffs_dev = ERR_PTR(-ENOENT); |
| else |
| ffs_dev->mounted = true; |
| |
| ffs_dev_unlock(); |
| return ffs_dev; |
| } |
| |
| static void ffs_release_dev(struct ffs_data *ffs_data) |
| { |
| struct ffs_dev *ffs_dev; |
| |
| ENTER(); |
| ffs_dev_lock(); |
| |
| ffs_dev = ffs_data->private_data; |
| if (ffs_dev) { |
| ffs_dev->mounted = false; |
| |
| if (ffs_dev->ffs_release_dev_callback) |
| ffs_dev->ffs_release_dev_callback(ffs_dev); |
| } |
| |
| ffs_dev_unlock(); |
| } |
| |
| static int ffs_ready(struct ffs_data *ffs) |
| { |
| struct ffs_dev *ffs_obj; |
| int ret = 0; |
| |
| ENTER(); |
| ffs_dev_lock(); |
| |
| ffs_obj = ffs->private_data; |
| if (!ffs_obj) { |
| ret = -EINVAL; |
| goto done; |
| } |
| if (WARN_ON(ffs_obj->desc_ready)) { |
| ret = -EBUSY; |
| goto done; |
| } |
| |
| ffs_obj->desc_ready = true; |
| ffs_obj->ffs_data = ffs; |
| |
| if (ffs_obj->ffs_ready_callback) { |
| ret = ffs_obj->ffs_ready_callback(ffs); |
| if (ret) |
| goto done; |
| } |
| |
| set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags); |
| done: |
| ffs_dev_unlock(); |
| return ret; |
| } |
| |
| static void ffs_closed(struct ffs_data *ffs) |
| { |
| struct ffs_dev *ffs_obj; |
| struct f_fs_opts *opts; |
| struct config_item *ci; |
| |
| ENTER(); |
| ffs_dev_lock(); |
| |
| ffs_obj = ffs->private_data; |
| if (!ffs_obj) |
| goto done; |
| |
| ffs_obj->desc_ready = false; |
| ffs_obj->ffs_data = NULL; |
| |
| if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && |
| ffs_obj->ffs_closed_callback) |
| ffs_obj->ffs_closed_callback(ffs); |
| |
| if (ffs_obj->opts) |
| opts = ffs_obj->opts; |
| else |
| goto done; |
| |
| if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent |
| || !kref_read(&opts->func_inst.group.cg_item.ci_kref)) |
| goto done; |
| |
| ci = opts->func_inst.group.cg_item.ci_parent->ci_parent; |
| ffs_dev_unlock(); |
| |
| if (test_bit(FFS_FL_BOUND, &ffs->flags)) |
| unregister_gadget_item(ci); |
| return; |
| done: |
| ffs_dev_unlock(); |
| } |
| |
| /* Misc helper functions ****************************************************/ |
| |
| static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) |
| { |
| return nonblock |
| ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN |
| : mutex_lock_interruptible(mutex); |
| } |
| |
| static char *ffs_prepare_buffer(const char __user *buf, size_t len) |
| { |
| char *data; |
| |
| if (unlikely(!len)) |
| return NULL; |
| |
| data = kmalloc(len, GFP_KERNEL); |
| if (unlikely(!data)) |
| return ERR_PTR(-ENOMEM); |
| |
| if (unlikely(copy_from_user(data, buf, len))) { |
| kfree(data); |
| return ERR_PTR(-EFAULT); |
| } |
| |
| pr_vdebug("Buffer from user space:\n"); |
| ffs_dump_mem("", data, len); |
| |
| return data; |
| } |
| |
| DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc); |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Michal Nazarewicz"); |