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linux/drivers/usb/gadget/f_fs.c
Dan Carpenter df4989954a usb: gadget: gadgetfs: potential use after free in unbind() 
ffs_data_put() can sometimes free "ffs" so I have moved the call down
a line below the dereference.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2013-08-27 15:03:32 -05:00

2467 lines
55 KiB
C
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/*
* 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
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/* #define DEBUG */
/* #define VERBOSE_DEBUG */
#include <linux/blkdev.h>
#include <linux/pagemap.h>
#include <linux/export.h>
#include <linux/hid.h>
#include <asm/unaligned.h>
#include <linux/usb/composite.h>
#include <linux/usb/functionfs.h>
#define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
/* Debugging ****************************************************************/
#ifdef VERBOSE_DEBUG
#ifndef pr_vdebug
# define pr_vdebug pr_debug
#endif /* pr_vdebug */
# define ffs_dump_mem(prefix, ptr, len) \
print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
#else
#ifndef pr_vdebug
# define pr_vdebug(...) do { } while (0)
#endif /* pr_vdebug */
# define ffs_dump_mem(prefix, ptr, len) do { } while (0)
#endif /* VERBOSE_DEBUG */
#define ENTER() pr_vdebug("%s()\n", __func__)
/* The data structure and setup file ****************************************/
enum ffs_state {
/*
* Waiting for descriptors and strings.
*
* In this state no open(2), read(2) or write(2) on epfiles
* may succeed (which should not be the problem as there
* should be no such files opened in the first place).
*/
FFS_READ_DESCRIPTORS,
FFS_READ_STRINGS,
/*
* We've got descriptors and strings. We are or have called
* functionfs_ready_callback(). functionfs_bind() may have
* been called but we don't know.
*
* This is the only state in which operations on epfiles may
* succeed.
*/
FFS_ACTIVE,
/*
* All endpoints have been closed. This state is also set if
* we encounter an unrecoverable error. The only
* unrecoverable error is situation when after reading strings
* from user space we fail to initialise epfiles or
* functionfs_ready_callback() returns with error (<0).
*
* In this state no open(2), read(2) or write(2) (both on ep0
* as well as epfile) may succeed (at this point epfiles are
* unlinked and all closed so this is not a problem; ep0 is
* also closed but ep0 file exists and so open(2) on ep0 must
* fail).
*/
FFS_CLOSING
};
enum ffs_setup_state {
/* There is no setup request pending. */
FFS_NO_SETUP,
/*
* User has read events and there was a setup request event
* there. The next read/write on ep0 will handle the
* request.
*/
FFS_SETUP_PENDING,
/*
* There was event pending but before user space handled it
* some other event was introduced which canceled existing
* setup. If this state is set read/write on ep0 return
* -EIDRM. This state is only set when adding event.
*/
FFS_SETUP_CANCELED
};
struct ffs_epfile;
struct ffs_function;
struct ffs_data {
struct usb_gadget *gadget;
/*
* Protect access read/write operations, only one read/write
* at a time. As a consequence protects ep0req and company.
* While setup request is being processed (queued) this is
* held.
*/
struct mutex mutex;
/*
* Protect access to endpoint related structures (basically
* usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
* endpoint zero.
*/
spinlock_t eps_lock;
/*
* XXX REVISIT do we need our own request? Since we are not
* handling setup requests immediately user space may be so
* slow that another setup will be sent to the gadget but this
* time not to us but another function and then there could be
* a race. Is that the case? Or maybe we can use cdev->req
* after all, maybe we just need some spinlock for that?
*/
struct usb_request *ep0req; /* P: mutex */
struct completion ep0req_completion; /* P: mutex */
int ep0req_status; /* P: mutex */
/* reference counter */
atomic_t ref;
/* how many files are opened (EP0 and others) */
atomic_t opened;
/* EP0 state */
enum ffs_state state;
/*
* Possible transitions:
* + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock
* happens only in ep0 read which is P: mutex
* + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock
* happens only in ep0 i/o which is P: mutex
* + FFS_SETUP_PENDING -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
* + FFS_SETUP_CANCELED -> FFS_NO_SETUP -- cmpxchg
*/
enum ffs_setup_state setup_state;
#define FFS_SETUP_STATE(ffs) \
((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state, \
FFS_SETUP_CANCELED, FFS_NO_SETUP))
/* Events & such. */
struct {
u8 types[4];
unsigned short count;
/* XXX REVISIT need to update it in some places, or do we? */
unsigned short can_stall;
struct usb_ctrlrequest setup;
wait_queue_head_t waitq;
} ev; /* the whole structure, P: ev.waitq.lock */
/* Flags */
unsigned long flags;
#define FFS_FL_CALL_CLOSED_CALLBACK 0
#define FFS_FL_BOUND 1
/* Active function */
struct ffs_function *func;
/*
* Device name, write once when file system is mounted.
* Intended for user to read if she wants.
*/
const char *dev_name;
/* Private data for our user (ie. gadget). Managed by user. */
void *private_data;
/* filled by __ffs_data_got_descs() */
/*
* Real descriptors are 16 bytes after raw_descs (so you need
* to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
* first full speed descriptor). raw_descs_length and
* raw_fs_descs_length do not have those 16 bytes added.
*/
const void *raw_descs;
unsigned raw_descs_length;
unsigned raw_fs_descs_length;
unsigned fs_descs_count;
unsigned hs_descs_count;
unsigned short strings_count;
unsigned short interfaces_count;
unsigned short eps_count;
unsigned short _pad1;
/* filled by __ffs_data_got_strings() */
/* ids in stringtabs are set in functionfs_bind() */
const void *raw_strings;
struct usb_gadget_strings **stringtabs;
/*
* File system's super block, write once when file system is
* mounted.
*/
struct super_block *sb;
/* File permissions, written once when fs is mounted */
struct ffs_file_perms {
umode_t mode;
kuid_t uid;
kgid_t gid;
} file_perms;
/*
* The endpoint files, filled by ffs_epfiles_create(),
* destroyed by ffs_epfiles_destroy().
*/
struct ffs_epfile *epfiles;
};
/* 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(void) __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 void ffs_func_free(struct ffs_function *func);
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 void ffs_func_unbind(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 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 */
struct usb_endpoint_descriptor *descs[2];
u8 num;
int status; /* P: epfile->mutex */
};
struct ffs_epfile {
/* Protects ep->ep and ep->req. */
struct mutex mutex;
wait_queue_head_t wait;
struct ffs_data *ffs;
struct ffs_ep *ep; /* P: ffs->eps_lock */
struct dentry *dentry;
char name[5];
unsigned char in; /* P: ffs->eps_lock */
unsigned char isoc; /* P: ffs->eps_lock */
unsigned char _pad;
};
static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
static struct inode *__must_check
ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
const struct file_operations *fops,
struct dentry **dentry_p);
/* 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_all(&ffs->ep0req_completion);
}
static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
{
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;
INIT_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 ffs->ep0req_status;
}
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(ffs) == FFS_SETUP_CANCELED)
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 = functionfs_ready_callback(ffs);
if (unlikely(ret < 0)) {
ffs->state = FFS_CLOSING;
return ret;
}
set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
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(ffs)) {
case FFS_SETUP_CANCELED:
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_CANCELED 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(ffs) == FFS_SETUP_CANCELED) {
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;
}
static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
size_t n)
{
/*
* We are holding ffs->ev.waitq.lock and ffs->mutex and we need
* to release them.
*/
struct usb_functionfs_event events[n];
unsigned i = 0;
memset(events, 0, sizeof events);
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);
if (n < ffs->ev.count) {
ffs->ev.count -= n;
memmove(ffs->ev.types, ffs->ev.types + n,
ffs->ev.count * sizeof *ffs->ev.types);
} else {
ffs->ev.count = 0;
}
spin_unlock_irq(&ffs->ev.waitq.lock);
mutex_unlock(&ffs->mutex);
return unlikely(__copy_to_user(buf, events, sizeof events))
? -EFAULT : sizeof events;
}
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(ffs) == FFS_SETUP_CANCELED)
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(ffs)) {
case FFS_SETUP_CANCELED:
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;
}
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(ffs) == FFS_SETUP_CANCELED) {
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 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,
};
/* "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_epfile_io(struct file *file,
char __user *buf, size_t len, int read)
{
struct ffs_epfile *epfile = file->private_data;
struct ffs_ep *ep;
char *data = NULL;
ssize_t ret;
int halt;
goto first_try;
do {
spin_unlock_irq(&epfile->ffs->eps_lock);
mutex_unlock(&epfile->mutex);
first_try:
/* Are we still active? */
if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
ret = -ENODEV;
goto error;
}
/* Wait for endpoint to be enabled */
ep = epfile->ep;
if (!ep) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
goto error;
}
if (wait_event_interruptible(epfile->wait,
(ep = epfile->ep))) {
ret = -EINTR;
goto error;
}
}
/* Do we halt? */
halt = !read == !epfile->in;
if (halt && epfile->isoc) {
ret = -EINVAL;
goto error;
}
/* Allocate & copy */
if (!halt && !data) {
data = kzalloc(len, GFP_KERNEL);
if (unlikely(!data))
return -ENOMEM;
if (!read &&
unlikely(__copy_from_user(data, buf, len))) {
ret = -EFAULT;
goto error;
}
}
/* We will be using request */
ret = ffs_mutex_lock(&epfile->mutex,
file->f_flags & O_NONBLOCK);
if (unlikely(ret))
goto error;
/*
* We're called from user space, we can use _irq rather then
* _irqsave
*/
spin_lock_irq(&epfile->ffs->eps_lock);
/*
* While we were acquiring mutex endpoint got disabled
* or changed?
*/
} while (unlikely(epfile->ep != ep));
/* Halt */
if (unlikely(halt)) {
if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
usb_ep_set_halt(ep->ep);
spin_unlock_irq(&epfile->ffs->eps_lock);
ret = -EBADMSG;
} else {
/* Fire the request */
DECLARE_COMPLETION_ONSTACK(done);
struct usb_request *req = ep->req;
req->context = &done;
req->complete = ffs_epfile_io_complete;
req->buf = data;
req->length = len;
ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
spin_unlock_irq(&epfile->ffs->eps_lock);
if (unlikely(ret < 0)) {
/* nop */
} else if (unlikely(wait_for_completion_interruptible(&done))) {
ret = -EINTR;
usb_ep_dequeue(ep->ep, req);
} else {
ret = ep->status;
if (read && ret > 0 &&
unlikely(copy_to_user(buf, data, ret)))
ret = -EFAULT;
}
}
mutex_unlock(&epfile->mutex);
error:
kfree(data);
return ret;
}
static ssize_t
ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
loff_t *ptr)
{
ENTER();
return ffs_epfile_io(file, (char __user *)buf, len, 0);
}
static ssize_t
ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
{
ENTER();
return ffs_epfile_io(file, buf, len, 1);
}
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_epfile_release(struct inode *inode, struct file *file)
{
struct ffs_epfile *epfile = inode->i_private;
ENTER();
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;
int ret;
ENTER();
if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
return -ENODEV;
spin_lock_irq(&epfile->ffs->eps_lock);
if (likely(epfile->ep)) {
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;
default:
ret = -ENOTTY;
}
} else {
ret = -ENODEV;
}
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 = ffs_epfile_write,
.read = ffs_epfile_read,
.release = ffs_epfile_release,
.unlocked_ioctl = ffs_epfile_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 timespec current_time = CURRENT_TIME;
inode->i_ino = get_next_ino();
inode->i_mode = perms->mode;
inode->i_uid = perms->uid;
inode->i_gid = perms->gid;
inode->i_atime = current_time;
inode->i_mtime = current_time;
inode->i_ctime = current_time;
inode->i_private = data;
if (fops)
inode->i_fop = fops;
if (iops)
inode->i_op = iops;
}
return inode;
}
/* Create "regular" file */
static struct inode *ffs_sb_create_file(struct super_block *sb,
const char *name, void *data,
const struct file_operations *fops,
struct dentry **dentry_p)
{
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);
if (dentry_p)
*dentry_p = dentry;
return inode;
}
/* 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;
union {
/* set by ffs_fs_mount(), read by ffs_sb_fill() */
void *private_data;
/* set by ffs_sb_fill(), read by ffs_fs_mount */
struct ffs_data *ffs_data;
};
};
static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
{
struct ffs_sb_fill_data *data = _data;
struct inode *inode;
struct ffs_data *ffs;
ENTER();
/* Initialise data */
ffs = ffs_data_new();
if (unlikely(!ffs))
goto Enomem;
ffs->sb = sb;
ffs->dev_name = kstrdup(data->dev_name, GFP_KERNEL);
if (unlikely(!ffs->dev_name))
goto Enomem;
ffs->file_perms = data->perms;
ffs->private_data = data->private_data;
/* used by the caller of this function */
data->ffs_data = ffs;
sb->s_fs_info = ffs;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_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))
goto Enomem;
/* EP0 file */
if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
&ffs_ep0_operations, NULL)))
goto Enomem;
return 0;
Enomem:
return -ENOMEM;
}
static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
{
ENTER();
if (!opts || !*opts)
return 0;
for (;;) {
unsigned long value;
char *eq, *comma;
/* Option limit */
comma = strchr(opts, ',');
if (comma)
*comma = 0;
/* Value limit */
eq = strchr(opts, '=');
if (unlikely(!eq)) {
pr_err("'=' missing in %s\n", opts);
return -EINVAL;
}
*eq = 0;
/* Parse value */
if (kstrtoul(eq + 1, 0, &value)) {
pr_err("%s: invalid value: %s\n", opts, eq + 1);
return -EINVAL;
}
/* Interpret option */
switch (eq - opts) {
case 5:
if (!memcmp(opts, "rmode", 5))
data->root_mode = (value & 0555) | S_IFDIR;
else if (!memcmp(opts, "fmode", 5))
data->perms.mode = (value & 0666) | S_IFREG;
else
goto invalid;
break;
case 4:
if (!memcmp(opts, "mode", 4)) {
data->root_mode = (value & 0555) | S_IFDIR;
data->perms.mode = (value & 0666) | S_IFREG;
} else {
goto invalid;
}
break;
case 3:
if (!memcmp(opts, "uid", 3)) {
data->perms.uid = make_kuid(current_user_ns(), value);
if (!uid_valid(data->perms.uid)) {
pr_err("%s: unmapped value: %lu\n", opts, value);
return -EINVAL;
}
} else if (!memcmp(opts, "gid", 3)) {
data->perms.gid = make_kgid(current_user_ns(), value);
if (!gid_valid(data->perms.gid)) {
pr_err("%s: unmapped value: %lu\n", opts, value);
return -EINVAL;
}
} else {
goto invalid;
}
break;
default:
invalid:
pr_err("%s: invalid option\n", opts);
return -EINVAL;
}
/* Next iteration */
if (!comma)
break;
opts = comma + 1;
}
return 0;
}
/* "mount -t functionfs dev_name /dev/function" ends up here */
static struct dentry *
ffs_fs_mount(struct file_system_type *t, int flags,
const char *dev_name, void *opts)
{
struct ffs_sb_fill_data data = {
.perms = {
.mode = S_IFREG | 0600,
.uid = GLOBAL_ROOT_UID,
.gid = GLOBAL_ROOT_GID,
},
.root_mode = S_IFDIR | 0500,
};
struct dentry *rv;
int ret;
void *ffs_dev;
ENTER();
ret = ffs_fs_parse_opts(&data, opts);
if (unlikely(ret < 0))
return ERR_PTR(ret);
ffs_dev = functionfs_acquire_dev_callback(dev_name);
if (IS_ERR(ffs_dev))
return ffs_dev;
data.dev_name = dev_name;
data.private_data = ffs_dev;
rv = mount_nodev(t, flags, &data, ffs_sb_fill);
/* data.ffs_data is set by ffs_sb_fill */
if (IS_ERR(rv))
functionfs_release_dev_callback(data.ffs_data);
return rv;
}
static void
ffs_fs_kill_sb(struct super_block *sb)
{
ENTER();
kill_litter_super(sb);
if (sb->s_fs_info) {
functionfs_release_dev_callback(sb->s_fs_info);
ffs_data_put(sb->s_fs_info);
}
}
static struct file_system_type ffs_fs_type = {
.owner = THIS_MODULE,
.name = "functionfs",
.mount = ffs_fs_mount,
.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();
atomic_inc(&ffs->ref);
}
static void ffs_data_opened(struct ffs_data *ffs)
{
ENTER();
atomic_inc(&ffs->ref);
atomic_inc(&ffs->opened);
}
static void ffs_data_put(struct ffs_data *ffs)
{
ENTER();
if (unlikely(atomic_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));
kfree(ffs->dev_name);
kfree(ffs);
}
}
static void ffs_data_closed(struct ffs_data *ffs)
{
ENTER();
if (atomic_dec_and_test(&ffs->opened)) {
ffs->state = FFS_CLOSING;
ffs_data_reset(ffs);
}
ffs_data_put(ffs);
}
static struct ffs_data *ffs_data_new(void)
{
struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
if (unlikely(!ffs))
return 0;
ENTER();
atomic_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_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();
if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
functionfs_closed_callback(ffs);
BUG_ON(ffs->gadget);
if (ffs->epfiles)
ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
kfree(ffs->raw_descs);
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 = NULL;
ffs->raw_strings = NULL;
ffs->stringtabs = NULL;
ffs->raw_descs_length = 0;
ffs->raw_fs_descs_length = 0;
ffs->fs_descs_count = 0;
ffs->hs_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;
for (lang = ffs->stringtabs; *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);
init_waitqueue_head(&epfile->wait);
sprintf(epfiles->name, "ep%u", i);
if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
&ffs_epfile_operations,
&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) ||
waitqueue_active(&epfile->wait));
if (epfile->dentry) {
d_delete(epfile->dentry);
dput(epfile->dentry);
epfile->dentry = NULL;
}
}
kfree(epfiles);
}
static int functionfs_bind_config(struct usb_composite_dev *cdev,
struct usb_configuration *c,
struct ffs_data *ffs)
{
struct ffs_function *func;
int ret;
ENTER();
func = kzalloc(sizeof *func, GFP_KERNEL);
if (unlikely(!func))
return -ENOMEM;
func->function.name = "Function FS Gadget";
func->function.strings = ffs->stringtabs;
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.suspend = ffs_func_suspend;
func->function.resume = ffs_func_resume;
func->conf = c;
func->gadget = cdev->gadget;
func->ffs = ffs;
ffs_data_get(ffs);
ret = usb_add_function(c, &func->function);
if (unlikely(ret))
ffs_func_free(func);
return ret;
}
static void ffs_func_free(struct ffs_function *func)
{
struct ffs_ep *ep = func->eps;
unsigned count = func->ffs->eps_count;
unsigned long flags;
ENTER();
/* cleanup after autoconfig */
spin_lock_irqsave(&func->ffs->eps_lock, flags);
do {
if (ep->ep && ep->req)
usb_ep_free_request(ep->ep, ep->req);
ep->req = NULL;
++ep;
} while (--count);
spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
ffs_data_put(func->ffs);
kfree(func->eps);
/*
* eps and interfaces_nums are allocated in the same chunk so
* only one free is required. Descriptors are also allocated
* in the same chunk.
*/
kfree(func);
}
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);
do {
/* pending requests get nuked */
if (likely(ep->ep))
usb_ep_disable(ep->ep);
epfile->ep = NULL;
++ep;
++epfile;
} while (--count);
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);
do {
struct usb_endpoint_descriptor *ds;
ds = ep->descs[ep->descs[1] ? 1 : 0];
ep->ep->driver_data = ep;
ep->ep->desc = ds;
ret = usb_ep_enable(ep->ep);
if (likely(!ret)) {
epfile->ep = ep;
epfile->in = usb_endpoint_dir_in(ds);
epfile->isoc = usb_endpoint_xfer_isoc(ds);
} else {
break;
}
wake_up(&epfile->wait);
++ep;
++epfile;
} while (--count);
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
};
typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
u8 *valuep,
struct usb_descriptor_header *desc,
void *priv);
static int __must_check ffs_do_desc(char *data, unsigned len,
ffs_entity_callback entity, void *priv)
{
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);
}
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 HID_DT_HID:
pr_vdebug("hid descriptor\n");
if (length != sizeof(struct hid_descriptor))
goto inv_length;
break;
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_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;
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_desc(data, len, entity, priv);
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_data *ffs = priv;
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 >= ffs->interfaces_count)
ffs->interfaces_count = *valuep + 1;
break;
case FFS_STRING:
/*
* Strings are indexed from 1 (0 is magic ;) reserved
* for languages list or some such)
*/
if (*valuep > ffs->strings_count)
ffs->strings_count = *valuep;
break;
case FFS_ENDPOINT:
/* Endpoints are indexed from 1 as well. */
if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
break;
}
return 0;
}
static int __ffs_data_got_descs(struct ffs_data *ffs,
char *const _data, size_t len)
{
unsigned fs_count, hs_count;
int fs_len, ret = -EINVAL;
char *data = _data;
ENTER();
if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
get_unaligned_le32(data + 4) != len))
goto error;
fs_count = get_unaligned_le32(data + 8);
hs_count = get_unaligned_le32(data + 12);
if (!fs_count && !hs_count)
goto einval;
data += 16;
len -= 16;
if (likely(fs_count)) {
fs_len = ffs_do_descs(fs_count, data, len,
__ffs_data_do_entity, ffs);
if (unlikely(fs_len < 0)) {
ret = fs_len;
goto error;
}
data += fs_len;
len -= fs_len;
} else {
fs_len = 0;
}
if (likely(hs_count)) {
ret = ffs_do_descs(hs_count, data, len,
__ffs_data_do_entity, ffs);
if (unlikely(ret < 0))
goto error;
} else {
ret = 0;
}
if (unlikely(len != ret))
goto einval;
ffs->raw_fs_descs_length = fs_len;
ffs->raw_descs_length = fs_len + ret;
ffs->raw_descs = _data;
ffs->fs_descs_count = fs_count;
ffs->hs_descs_count = hs_count;
return 0;
einval:
ret = -EINVAL;
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;
struct usb_string *strings, *s;
const char *data = _data;
ENTER();
if (unlikely(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. */
{
struct {
struct usb_gadget_strings *stringtabs[lang_count + 1];
struct usb_gadget_strings stringtab[lang_count];
struct usb_string strings[lang_count*(needed_count+1)];
} *d;
unsigned i = 0;
d = kmalloc(sizeof *d, GFP_KERNEL);
if (unlikely(!d)) {
kfree(_data);
return -ENOMEM;
}
stringtabs = d->stringtabs;
t = d->stringtab;
i = lang_count;
do {
*stringtabs++ = t++;
} while (--i);
*stringtabs = NULL;
stringtabs = d->stringtabs;
t = d->stringtab;
s = d->strings;
strings = s;
}
/* 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_CANCELED;
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:
BUG();
}
{
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);
}
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_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;
/*
* If hs_descriptors is not NULL then we are reading hs
* descriptors now
*/
const int isHS = func->function.hs_descriptors != NULL;
unsigned idx;
if (type != FFS_DESCRIPTOR)
return 0;
if (isHS)
func->function.hs_descriptors[(long)valuep] = desc;
else
func->function.fs_descriptors[(long)valuep] = desc;
if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
return 0;
idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
ffs_ep = func->eps + idx;
if (unlikely(ffs_ep->descs[isHS])) {
pr_vdebug("two %sspeed descriptors for EP %d\n",
isHS ? "high" : "full",
ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
return -EINVAL;
}
ffs_ep->descs[isHS] = 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;
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;
}
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(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 = gadget_is_dualspeed(func->gadget) &&
func->ffs->hs_descs_count;
int ret;
/* Make it a single chunk, less management later on */
struct {
struct ffs_ep eps[ffs->eps_count];
struct usb_descriptor_header
*fs_descs[full ? ffs->fs_descs_count + 1 : 0];
struct usb_descriptor_header
*hs_descs[high ? ffs->hs_descs_count + 1 : 0];
short inums[ffs->interfaces_count];
char raw_descs[high ? ffs->raw_descs_length
: ffs->raw_fs_descs_length];
} *data;
ENTER();
/* Only high speed but not supported by gadget? */
if (unlikely(!(full | high)))
return -ENOTSUPP;
/* Allocate */
data = kmalloc(sizeof *data, GFP_KERNEL);
if (unlikely(!data))
return -ENOMEM;
/* Zero */
memset(data->eps, 0, sizeof data->eps);
memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
memset(data->inums, 0xff, sizeof data->inums);
for (ret = ffs->eps_count; ret; --ret)
data->eps[ret].num = -1;
/* Save pointers */
func->eps = data->eps;
func->interfaces_nums = data->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 = data->fs_descs;
ret = ffs_do_descs(ffs->fs_descs_count,
data->raw_descs,
sizeof data->raw_descs,
__ffs_func_bind_do_descs, func);
if (unlikely(ret < 0))
goto error;
} else {
ret = 0;
}
if (likely(high)) {
func->function.hs_descriptors = data->hs_descs;
ret = ffs_do_descs(ffs->hs_descs_count,
data->raw_descs + ret,
(sizeof data->raw_descs) - ret,
__ffs_func_bind_do_descs, func);
}
/*
* 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),
data->raw_descs, sizeof data->raw_descs,
__ffs_func_bind_do_nums, func);
if (unlikely(ret < 0))
goto error;
/* 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;
}
/* Other USB function hooks *************************************************/
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;
ENTER();
if (ffs->func == func) {
ffs_func_eps_disable(func);
ffs->func = NULL;
}
ffs_event_add(ffs, FUNCTIONFS_UNBIND);
ffs_func_free(func);
}
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_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) but what to do with any
* other request?
*/
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;
break;
default:
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 0;
}
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;
}
/* 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;
}
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