| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Michal Nazarewicz | 7463 | 45.58% | 23 | 16.31% |
| Andrzej Pietrasiewicz | 5293 | 32.33% | 17 | 12.06% |
| Robert Baldyga | 1545 | 9.44% | 11 | 7.80% |
| David Howells | 381 | 2.33% | 1 | 0.71% |
| Al Viro | 370 | 2.26% | 12 | 8.51% |
| Manu Gautam | 198 | 1.21% | 1 | 0.71% |
| Vincent Pelletier | 165 | 1.01% | 8 | 5.67% |
| Felix Hädicke | 163 | 1.00% | 4 | 2.84% |
| Jerry Zhang | 162 | 0.99% | 5 | 3.55% |
| John Keeping | 83 | 0.51% | 2 | 1.42% |
| Eric W. Biedermann | 42 | 0.26% | 2 | 1.42% |
| Rui Miguel Silva | 42 | 0.26% | 2 | 1.42% |
| Jack Pham | 39 | 0.24% | 2 | 1.42% |
| Dan Carpenter | 39 | 0.24% | 4 | 2.84% |
| David Cohen | 36 | 0.22% | 1 | 0.71% |
| Chao Bi | 33 | 0.20% | 1 | 0.71% |
| Krzysztof Opasiak | 31 | 0.19% | 2 | 1.42% |
| Shen Jing | 31 | 0.19% | 1 | 0.71% |
| Lars-Peter Clausen | 29 | 0.18% | 3 | 2.13% |
| Koen Beel | 24 | 0.15% | 1 | 0.71% |
| Fei Yang | 20 | 0.12% | 2 | 1.42% |
| Marek Szyprowski | 19 | 0.12% | 1 | 0.71% |
| Changbin Du | 16 | 0.10% | 1 | 0.71% |
| Jim Baxter | 15 | 0.09% | 1 | 0.71% |
| Baolin Wang | 15 | 0.09% | 1 | 0.71% |
| Christoph Hellwig | 14 | 0.09% | 3 | 2.13% |
| Hemant Kumar | 12 | 0.07% | 1 | 0.71% |
| Greg Kroah-Hartman | 11 | 0.07% | 3 | 2.13% |
| Deepa Dinamani | 9 | 0.05% | 2 | 1.42% |
| Felipe Balbi | 9 | 0.05% | 3 | 2.13% |
| John Stultz | 6 | 0.04% | 1 | 0.71% |
| Andrew Gabbasov | 6 | 0.04% | 1 | 0.71% |
| William Wu | 5 | 0.03% | 1 | 0.71% |
| Chuansheng Liu | 5 | 0.03% | 1 | 0.71% |
| Thomas Meyer | 5 | 0.03% | 1 | 0.71% |
| Linus Torvalds | 5 | 0.03% | 1 | 0.71% |
| Elena Reshetova | 4 | 0.02% | 1 | 0.71% |
| Tatyana Brokhman | 4 | 0.02% | 1 | 0.71% |
| Ingo Molnar | 3 | 0.02% | 1 | 0.71% |
| Mario Schuknecht | 3 | 0.02% | 1 | 0.71% |
| Daniel Walter | 3 | 0.02% | 1 | 0.71% |
| Randy Dunlap | 3 | 0.02% | 1 | 0.71% |
| Paul Gortmaker | 3 | 0.02% | 1 | 0.71% |
| Jim Lin | 2 | 0.01% | 1 | 0.71% |
| Kirill A. Shutemov | 2 | 0.01% | 1 | 0.71% |
| Wolfram Sang | 2 | 0.01% | 1 | 0.71% |
| Bhumika Goyal | 1 | 0.01% | 1 | 0.71% |
| Peter Zijlstra | 1 | 0.01% | 1 | 0.71% |
| Sebastian Andrzej Siewior | 1 | 0.01% | 1 | 0.71% |
| Daniel Wagner | 1 | 0.01% | 1 | 0.71% |
| Total | 16374 | 141 |
// 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/mmu_context.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) { mm_segment_t oldfs = get_fs(); set_fs(USER_DS); use_mm(io_data->mm); ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); unuse_mm(io_data->mm); set_fs(oldfs); } 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->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->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)) { 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; int value; ENTER(); spin_lock_irq(&epfile->ffs->eps_lock); 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_irq(&epfile->ffs->eps_lock); 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; } #ifdef CONFIG_COMPAT static long ffs_epfile_compat_ioctl(struct file *file, unsigned code, unsigned long value) { return ffs_epfile_ioctl(file, code, value); } #endif 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, #ifdef CONFIG_COMPAT .compat_ioctl = ffs_epfile_compat_ioctl, #endif }; /* 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_param_specs[] = { 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 const struct fs_parameter_description ffs_fs_fs_parameters = { .name = "kAFS", .specs = ffs_fs_param_specs, }; 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) || waitqueue_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; } 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; /* FALL THROUGH */ 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) >= FIELD_SIZEOF(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");
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