OSCL-LXR linux-6.0.1/​drivers/​usb/​core/​devio.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0+
 /*****************************************************************************/
 
 /*
  *      devio.c  --  User space communication with USB devices.
  *
  *      Copyright (C) 1999-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
  *
  *  This file implements the usbfs/x/y files, where
  *  x is the bus number and y the device number.
  *
  *  It allows user space programs/"drivers" to communicate directly
  *  with USB devices without intervening kernel driver.
  *
  *  Revision history
  *    22.12.1999   0.1   Initial release (split from proc_usb.c)
  *    04.01.2000   0.2   Turned into its own filesystem
  *    30.09.2005   0.3   Fix user-triggerable oops in async URB delivery
  *               (CAN-2005-3055)
  */
 
 /*****************************************************************************/
 
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/slab.h>
 #include <linux/signal.h>
 #include <linux/poll.h>
 #include <linux/module.h>
 #include <linux/string.h>
 #include <linux/usb.h>
 #include <linux/usbdevice_fs.h>
 #include <linux/usb/hcd.h>  /* for usbcore internals */
 #include <linux/usb/quirks.h>
 #include <linux/cdev.h>
 #include <linux/notifier.h>
 #include <linux/security.h>
 #include <linux/user_namespace.h>
 #include <linux/scatterlist.h>
 #include <linux/uaccess.h>
 #include <linux/dma-mapping.h>
 #include <asm/byteorder.h>
 #include <linux/moduleparam.h>
 
 #include "usb.h"
 
 #ifdef CONFIG_PM
 #define MAYBE_CAP_SUSPEND   USBDEVFS_CAP_SUSPEND
 #else
 #define MAYBE_CAP_SUSPEND   0
 #endif
 
 #define USB_MAXBUS          64
 #define USB_DEVICE_MAX          (USB_MAXBUS * 128)
 #define USB_SG_SIZE         16384 /* split-size for large txs */
 
 /* Mutual exclusion for ps->list in resume vs. release and remove */
 static DEFINE_MUTEX(usbfs_mutex);
 
 struct usb_dev_state {
     struct list_head list;      /* state list */
     struct usb_device *dev;
     struct file *file;
     spinlock_t lock;            /* protects the async urb lists */
     struct list_head async_pending;
     struct list_head async_completed;
     struct list_head memory_list;
     wait_queue_head_t wait;     /* wake up if a request completed */
     wait_queue_head_t wait_for_resume;   /* wake up upon runtime resume */
     unsigned int discsignr;
     struct pid *disc_pid;
     const struct cred *cred;
     sigval_t disccontext;
     unsigned long ifclaimed;
     u32 disabled_bulk_eps;
     unsigned long interface_allowed_mask;
     int not_yet_resumed;
     bool suspend_allowed;
     bool privileges_dropped;
 };
 
 struct usb_memory {
     struct list_head memlist;
     int vma_use_count;
     int urb_use_count;
     u32 size;
     void *mem;
     dma_addr_t dma_handle;
     unsigned long vm_start;
     struct usb_dev_state *ps;
 };
 
 struct async {
     struct list_head asynclist;
     struct usb_dev_state *ps;
     struct pid *pid;
     const struct cred *cred;
     unsigned int signr;
     unsigned int ifnum;
     void __user *userbuffer;
     void __user *userurb;
     sigval_t userurb_sigval;
     struct urb *urb;
     struct usb_memory *usbm;
     unsigned int mem_usage;
     int status;
     u8 bulk_addr;
     u8 bulk_status;
 };
 
 static bool usbfs_snoop;
 module_param(usbfs_snoop, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(usbfs_snoop, "true to log all usbfs traffic");
 
 static unsigned usbfs_snoop_max = 65536;
 module_param(usbfs_snoop_max, uint, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(usbfs_snoop_max,
         "maximum number of bytes to print while snooping");
 
 #define snoop(dev, format, arg...)              \
     do {                            \
         if (usbfs_snoop)                \
             dev_info(dev, format, ## arg);      \
     } while (0)
 
 enum snoop_when {
     SUBMIT, COMPLETE
 };
 
 #define USB_DEVICE_DEV      MKDEV(USB_DEVICE_MAJOR, 0)
 
 /* Limit on the total amount of memory we can allocate for transfers */
 static u32 usbfs_memory_mb = 16;
 module_param(usbfs_memory_mb, uint, 0644);
 MODULE_PARM_DESC(usbfs_memory_mb,
         "maximum MB allowed for usbfs buffers (0 = no limit)");
 
 /* Hard limit, necessary to avoid arithmetic overflow */
 #define USBFS_XFER_MAX         (UINT_MAX / 2 - 1000000)
 
 static DEFINE_SPINLOCK(usbfs_memory_usage_lock);
 static u64 usbfs_memory_usage;  /* Total memory currently allocated */
 
 /* Check whether it's okay to allocate more memory for a transfer */
 static int usbfs_increase_memory_usage(u64 amount)
 {
     u64 lim, total_mem;
     unsigned long flags;
     int ret;
 
     lim = READ_ONCE(usbfs_memory_mb);
     lim <<= 20;
 
     ret = 0;
     spin_lock_irqsave(&usbfs_memory_usage_lock, flags);
     total_mem = usbfs_memory_usage + amount;
     if (lim > 0 && total_mem > lim)
         ret = -ENOMEM;
     else
         usbfs_memory_usage = total_mem;
     spin_unlock_irqrestore(&usbfs_memory_usage_lock, flags);
 
     return ret;
 }
 
 /* Memory for a transfer is being deallocated */
 static void usbfs_decrease_memory_usage(u64 amount)
 {
     unsigned long flags;
 
     spin_lock_irqsave(&usbfs_memory_usage_lock, flags);
     if (amount > usbfs_memory_usage)
         usbfs_memory_usage = 0;
     else
         usbfs_memory_usage -= amount;
     spin_unlock_irqrestore(&usbfs_memory_usage_lock, flags);
 }
 
 static int connected(struct usb_dev_state *ps)
 {
     return (!list_empty(&ps->list) &&
             ps->dev->state != USB_STATE_NOTATTACHED);
 }
 
 static void dec_usb_memory_use_count(struct usb_memory *usbm, int *count)
 {
     struct usb_dev_state *ps = usbm->ps;
     unsigned long flags;
 
     spin_lock_irqsave(&ps->lock, flags);
     --*count;
     if (usbm->urb_use_count == 0 && usbm->vma_use_count == 0) {
         list_del(&usbm->memlist);
         spin_unlock_irqrestore(&ps->lock, flags);
 
         usb_free_coherent(ps->dev, usbm->size, usbm->mem,
                 usbm->dma_handle);
         usbfs_decrease_memory_usage(
             usbm->size + sizeof(struct usb_memory));
         kfree(usbm);
     } else {
         spin_unlock_irqrestore(&ps->lock, flags);
     }
 }
 
 static void usbdev_vm_open(struct vm_area_struct *vma)
 {
     struct usb_memory *usbm = vma->vm_private_data;
     unsigned long flags;
 
     spin_lock_irqsave(&usbm->ps->lock, flags);
     ++usbm->vma_use_count;
     spin_unlock_irqrestore(&usbm->ps->lock, flags);
 }
 
 static void usbdev_vm_close(struct vm_area_struct *vma)
 {
     struct usb_memory *usbm = vma->vm_private_data;
 
     dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
 }
 
 static const struct vm_operations_struct usbdev_vm_ops = {
     .open = usbdev_vm_open,
     .close = usbdev_vm_close
 };
 
 static int usbdev_mmap(struct file *file, struct vm_area_struct *vma)
 {
     struct usb_memory *usbm = NULL;
     struct usb_dev_state *ps = file->private_data;
     struct usb_hcd *hcd = bus_to_hcd(ps->dev->bus);
     size_t size = vma->vm_end - vma->vm_start;
     void *mem;
     unsigned long flags;
     dma_addr_t dma_handle;
     int ret;
 
     ret = usbfs_increase_memory_usage(size + sizeof(struct usb_memory));
     if (ret)
         goto error;
 
     usbm = kzalloc(sizeof(struct usb_memory), GFP_KERNEL);
     if (!usbm) {
         ret = -ENOMEM;
         goto error_decrease_mem;
     }
 
     mem = usb_alloc_coherent(ps->dev, size, GFP_USER | __GFP_NOWARN,
             &dma_handle);
     if (!mem) {
         ret = -ENOMEM;
         goto error_free_usbm;
     }
 
     memset(mem, 0, size);
 
     usbm->mem = mem;
     usbm->dma_handle = dma_handle;
     usbm->size = size;
     usbm->ps = ps;
     usbm->vm_start = vma->vm_start;
     usbm->vma_use_count = 1;
     INIT_LIST_HEAD(&usbm->memlist);
 
     if (hcd->localmem_pool || !hcd_uses_dma(hcd)) {
         if (remap_pfn_range(vma, vma->vm_start,
                     virt_to_phys(usbm->mem) >> PAGE_SHIFT,
                     size, vma->vm_page_prot) < 0) {
             dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
             return -EAGAIN;
         }
     } else {
         if (dma_mmap_coherent(hcd->self.sysdev, vma, mem, dma_handle,
                       size)) {
             dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
             return -EAGAIN;
         }
     }
 
     vma->vm_flags |= VM_IO;
     vma->vm_flags |= (VM_DONTEXPAND | VM_DONTDUMP);
     vma->vm_ops = &usbdev_vm_ops;
     vma->vm_private_data = usbm;
 
     spin_lock_irqsave(&ps->lock, flags);
     list_add_tail(&usbm->memlist, &ps->memory_list);
     spin_unlock_irqrestore(&ps->lock, flags);
 
     return 0;
 
 error_free_usbm:
     kfree(usbm);
 error_decrease_mem:
     usbfs_decrease_memory_usage(size + sizeof(struct usb_memory));
 error:
     return ret;
 }
 
 static ssize_t usbdev_read(struct file *file, char __user *buf, size_t nbytes,
                loff_t *ppos)
 {
     struct usb_dev_state *ps = file->private_data;
     struct usb_device *dev = ps->dev;
     ssize_t ret = 0;
     unsigned len;
     loff_t pos;
     int i;
 
     pos = *ppos;
     usb_lock_device(dev);
     if (!connected(ps)) {
         ret = -ENODEV;
         goto err;
     } else if (pos < 0) {
         ret = -EINVAL;
         goto err;
     }
 
     if (pos < sizeof(struct usb_device_descriptor)) {
         /* 18 bytes - fits on the stack */
         struct usb_device_descriptor temp_desc;
 
         memcpy(&temp_desc, &dev->descriptor, sizeof(dev->descriptor));
         le16_to_cpus(&temp_desc.bcdUSB);
         le16_to_cpus(&temp_desc.idVendor);
         le16_to_cpus(&temp_desc.idProduct);
         le16_to_cpus(&temp_desc.bcdDevice);
 
         len = sizeof(struct usb_device_descriptor) - pos;
         if (len > nbytes)
             len = nbytes;
         if (copy_to_user(buf, ((char *)&temp_desc) + pos, len)) {
             ret = -EFAULT;
             goto err;
         }
 
         *ppos += len;
         buf += len;
         nbytes -= len;
         ret += len;
     }
 
     pos = sizeof(struct usb_device_descriptor);
     for (i = 0; nbytes && i < dev->descriptor.bNumConfigurations; i++) {
         struct usb_config_descriptor *config =
             (struct usb_config_descriptor *)dev->rawdescriptors[i];
         unsigned int length = le16_to_cpu(config->wTotalLength);
 
         if (*ppos < pos + length) {
 
             /* The descriptor may claim to be longer than it
              * really is.  Here is the actual allocated length. */
             unsigned alloclen =
                 le16_to_cpu(dev->config[i].desc.wTotalLength);
 
             len = length - (*ppos - pos);
             if (len > nbytes)
                 len = nbytes;
 
             /* Simply don't write (skip over) unallocated parts */
             if (alloclen > (*ppos - pos)) {
                 alloclen -= (*ppos - pos);
                 if (copy_to_user(buf,
                     dev->rawdescriptors[i] + (*ppos - pos),
                     min(len, alloclen))) {
                     ret = -EFAULT;
                     goto err;
                 }
             }
 
             *ppos += len;
             buf += len;
             nbytes -= len;
             ret += len;
         }
 
         pos += length;
     }
 
 err:
     usb_unlock_device(dev);
     return ret;
 }
 
 /*
  * async list handling
  */
 
 static struct async *alloc_async(unsigned int numisoframes)
 {
     struct async *as;
 
     as = kzalloc(sizeof(struct async), GFP_KERNEL);
     if (!as)
         return NULL;
     as->urb = usb_alloc_urb(numisoframes, GFP_KERNEL);
     if (!as->urb) {
         kfree(as);
         return NULL;
     }
     return as;
 }
 
 static void free_async(struct async *as)
 {
     int i;
 
     put_pid(as->pid);
     if (as->cred)
         put_cred(as->cred);
     for (i = 0; i < as->urb->num_sgs; i++) {
         if (sg_page(&as->urb->sg[i]))
             kfree(sg_virt(&as->urb->sg[i]));
     }
 
     kfree(as->urb->sg);
     if (as->usbm == NULL)
         kfree(as->urb->transfer_buffer);
     else
         dec_usb_memory_use_count(as->usbm, &as->usbm->urb_use_count);
 
     kfree(as->urb->setup_packet);
     usb_free_urb(as->urb);
     usbfs_decrease_memory_usage(as->mem_usage);
     kfree(as);
 }
 
 static void async_newpending(struct async *as)
 {
     struct usb_dev_state *ps = as->ps;
     unsigned long flags;
 
     spin_lock_irqsave(&ps->lock, flags);
     list_add_tail(&as->asynclist, &ps->async_pending);
     spin_unlock_irqrestore(&ps->lock, flags);
 }
 
 static void async_removepending(struct async *as)
 {
     struct usb_dev_state *ps = as->ps;
     unsigned long flags;
 
     spin_lock_irqsave(&ps->lock, flags);
     list_del_init(&as->asynclist);
     spin_unlock_irqrestore(&ps->lock, flags);
 }
 
 static struct async *async_getcompleted(struct usb_dev_state *ps)
 {
     unsigned long flags;
     struct async *as = NULL;
 
     spin_lock_irqsave(&ps->lock, flags);
     if (!list_empty(&ps->async_completed)) {
         as = list_entry(ps->async_completed.next, struct async,
                 asynclist);
         list_del_init(&as->asynclist);
     }
     spin_unlock_irqrestore(&ps->lock, flags);
     return as;
 }
 
 static struct async *async_getpending(struct usb_dev_state *ps,
                          void __user *userurb)
 {
     struct async *as;
 
     list_for_each_entry(as, &ps->async_pending, asynclist)
         if (as->userurb == userurb) {
             list_del_init(&as->asynclist);
             return as;
         }
 
     return NULL;
 }
 
 static void snoop_urb(struct usb_device *udev,
         void __user *userurb, int pipe, unsigned length,
         int timeout_or_status, enum snoop_when when,
         unsigned char *data, unsigned data_len)
 {
     static const char *types[] = {"isoc", "int", "ctrl", "bulk"};
     static const char *dirs[] = {"out", "in"};
     int ep;
     const char *t, *d;
 
     if (!usbfs_snoop)
         return;
 
     ep = usb_pipeendpoint(pipe);
     t = types[usb_pipetype(pipe)];
     d = dirs[!!usb_pipein(pipe)];
 
     if (userurb) {      /* Async */
         if (when == SUBMIT)
             dev_info(&udev->dev, "userurb %px, ep%d %s-%s, "
                     "length %u\n",
                     userurb, ep, t, d, length);
         else
             dev_info(&udev->dev, "userurb %px, ep%d %s-%s, "
                     "actual_length %u status %d\n",
                     userurb, ep, t, d, length,
                     timeout_or_status);
     } else {
         if (when == SUBMIT)
             dev_info(&udev->dev, "ep%d %s-%s, length %u, "
                     "timeout %d\n",
                     ep, t, d, length, timeout_or_status);
         else
             dev_info(&udev->dev, "ep%d %s-%s, actual_length %u, "
                     "status %d\n",
                     ep, t, d, length, timeout_or_status);
     }
 
     data_len = min(data_len, usbfs_snoop_max);
     if (data && data_len > 0) {
         print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_NONE, 32, 1,
             data, data_len, 1);
     }
 }
 
 static void snoop_urb_data(struct urb *urb, unsigned len)
 {
     int i, size;
 
     len = min(len, usbfs_snoop_max);
     if (!usbfs_snoop || len == 0)
         return;
 
     if (urb->num_sgs == 0) {
         print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_NONE, 32, 1,
             urb->transfer_buffer, len, 1);
         return;
     }
 
     for (i = 0; i < urb->num_sgs && len; i++) {
         size = (len > USB_SG_SIZE) ? USB_SG_SIZE : len;
         print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_NONE, 32, 1,
             sg_virt(&urb->sg[i]), size, 1);
         len -= size;
     }
 }
 
 static int copy_urb_data_to_user(u8 __user *userbuffer, struct urb *urb)
 {
     unsigned i, len, size;
 
     if (urb->number_of_packets > 0)     /* Isochronous */
         len = urb->transfer_buffer_length;
     else                    /* Non-Isoc */
         len = urb->actual_length;
 
     if (urb->num_sgs == 0) {
         if (copy_to_user(userbuffer, urb->transfer_buffer, len))
             return -EFAULT;
         return 0;
     }
 
     for (i = 0; i < urb->num_sgs && len; i++) {
         size = (len > USB_SG_SIZE) ? USB_SG_SIZE : len;
         if (copy_to_user(userbuffer, sg_virt(&urb->sg[i]), size))
             return -EFAULT;
         userbuffer += size;
         len -= size;
     }
 
     return 0;
 }
 
 #define AS_CONTINUATION 1
 #define AS_UNLINK   2
 
 static void cancel_bulk_urbs(struct usb_dev_state *ps, unsigned bulk_addr)
 __releases(ps->lock)
 __acquires(ps->lock)
 {
     struct urb *urb;
     struct async *as;
 
     /* Mark all the pending URBs that match bulk_addr, up to but not
      * including the first one without AS_CONTINUATION.  If such an
      * URB is encountered then a new transfer has already started so
      * the endpoint doesn't need to be disabled; otherwise it does.
      */
     list_for_each_entry(as, &ps->async_pending, asynclist) {
         if (as->bulk_addr == bulk_addr) {
             if (as->bulk_status != AS_CONTINUATION)
                 goto rescan;
             as->bulk_status = AS_UNLINK;
             as->bulk_addr = 0;
         }
     }
     ps->disabled_bulk_eps |= (1 << bulk_addr);
 
     /* Now carefully unlink all the marked pending URBs */
  rescan:
     list_for_each_entry_reverse(as, &ps->async_pending, asynclist) {
         if (as->bulk_status == AS_UNLINK) {
             as->bulk_status = 0;        /* Only once */
             urb = as->urb;
             usb_get_urb(urb);
             spin_unlock(&ps->lock);     /* Allow completions */
             usb_unlink_urb(urb);
             usb_put_urb(urb);
             spin_lock(&ps->lock);
             goto rescan;
         }
     }
 }
 
 static void async_completed(struct urb *urb)
 {
     struct async *as = urb->context;
     struct usb_dev_state *ps = as->ps;
     struct pid *pid = NULL;
     const struct cred *cred = NULL;
     unsigned long flags;
     sigval_t addr;
     int signr, errno;
 
     spin_lock_irqsave(&ps->lock, flags);
     list_move_tail(&as->asynclist, &ps->async_completed);
     as->status = urb->status;
     signr = as->signr;
     if (signr) {
         errno = as->status;
         addr = as->userurb_sigval;
         pid = get_pid(as->pid);
         cred = get_cred(as->cred);
     }
     snoop(&urb->dev->dev, "urb complete\n");
     snoop_urb(urb->dev, as->userurb, urb->pipe, urb->actual_length,
             as->status, COMPLETE, NULL, 0);
     if (usb_urb_dir_in(urb))
         snoop_urb_data(urb, urb->actual_length);
 
     if (as->status < 0 && as->bulk_addr && as->status != -ECONNRESET &&
             as->status != -ENOENT)
         cancel_bulk_urbs(ps, as->bulk_addr);
 
     wake_up(&ps->wait);
     spin_unlock_irqrestore(&ps->lock, flags);
 
     if (signr) {
         kill_pid_usb_asyncio(signr, errno, addr, pid, cred);
         put_pid(pid);
         put_cred(cred);
     }
 }
 
 static void destroy_async(struct usb_dev_state *ps, struct list_head *list)
 {
     struct urb *urb;
     struct async *as;
     unsigned long flags;
 
     spin_lock_irqsave(&ps->lock, flags);
     while (!list_empty(list)) {
         as = list_last_entry(list, struct async, asynclist);
         list_del_init(&as->asynclist);
         urb = as->urb;
         usb_get_urb(urb);
 
         /* drop the spinlock so the completion handler can run */
         spin_unlock_irqrestore(&ps->lock, flags);
         usb_kill_urb(urb);
         usb_put_urb(urb);
         spin_lock_irqsave(&ps->lock, flags);
     }
     spin_unlock_irqrestore(&ps->lock, flags);
 }
 
 static void destroy_async_on_interface(struct usb_dev_state *ps,
                        unsigned int ifnum)
 {
     struct list_head *p, *q, hitlist;
     unsigned long flags;
 
     INIT_LIST_HEAD(&hitlist);
     spin_lock_irqsave(&ps->lock, flags);
     list_for_each_safe(p, q, &ps->async_pending)
         if (ifnum == list_entry(p, struct async, asynclist)->ifnum)
             list_move_tail(p, &hitlist);
     spin_unlock_irqrestore(&ps->lock, flags);
     destroy_async(ps, &hitlist);
 }
 
 static void destroy_all_async(struct usb_dev_state *ps)
 {
     destroy_async(ps, &ps->async_pending);
 }
 
 /*
  * interface claims are made only at the request of user level code,
  * which can also release them (explicitly or by closing files).
  * they're also undone when devices disconnect.
  */
 
 static int driver_probe(struct usb_interface *intf,
             const struct usb_device_id *id)
 {
     return -ENODEV;
 }
 
 static void driver_disconnect(struct usb_interface *intf)
 {
     struct usb_dev_state *ps = usb_get_intfdata(intf);
     unsigned int ifnum = intf->altsetting->desc.bInterfaceNumber;
 
     if (!ps)
         return;
 
     /* NOTE:  this relies on usbcore having canceled and completed
      * all pending I/O requests; 2.6 does that.
      */
 
     if (likely(ifnum < 8*sizeof(ps->ifclaimed)))
         clear_bit(ifnum, &ps->ifclaimed);
     else
         dev_warn(&intf->dev, "interface number %u out of range\n",
              ifnum);
 
     usb_set_intfdata(intf, NULL);
 
     /* force async requests to complete */
     destroy_async_on_interface(ps, ifnum);
 }
 
 /* We don't care about suspend/resume of claimed interfaces */
 static int driver_suspend(struct usb_interface *intf, pm_message_t msg)
 {
     return 0;
 }
 
 static int driver_resume(struct usb_interface *intf)
 {
     return 0;
 }
 
 /* The following routines apply to the entire device, not interfaces */
 void usbfs_notify_suspend(struct usb_device *udev)
 {
     /* We don't need to handle this */
 }
 
 void usbfs_notify_resume(struct usb_device *udev)
 {
     struct usb_dev_state *ps;
 
     /* Protect against simultaneous remove or release */
     mutex_lock(&usbfs_mutex);
     list_for_each_entry(ps, &udev->filelist, list) {
         WRITE_ONCE(ps->not_yet_resumed, 0);
         wake_up_all(&ps->wait_for_resume);
     }
     mutex_unlock(&usbfs_mutex);
 }
 
 struct usb_driver usbfs_driver = {
     .name =     "usbfs",
     .probe =    driver_probe,
     .disconnect =   driver_disconnect,
     .suspend =  driver_suspend,
     .resume =   driver_resume,
     .supports_autosuspend = 1,
 };
 
 static int claimintf(struct usb_dev_state *ps, unsigned int ifnum)
 {
     struct usb_device *dev = ps->dev;
     struct usb_interface *intf;
     int err;
 
     if (ifnum >= 8*sizeof(ps->ifclaimed))
         return -EINVAL;
     /* already claimed */
     if (test_bit(ifnum, &ps->ifclaimed))
         return 0;
 
     if (ps->privileges_dropped &&
             !test_bit(ifnum, &ps->interface_allowed_mask))
         return -EACCES;
 
     intf = usb_ifnum_to_if(dev, ifnum);
     if (!intf)
         err = -ENOENT;
     else {
         unsigned int old_suppress;
 
         /* suppress uevents while claiming interface */
         old_suppress = dev_get_uevent_suppress(&intf->dev);
         dev_set_uevent_suppress(&intf->dev, 1);
         err = usb_driver_claim_interface(&usbfs_driver, intf, ps);
         dev_set_uevent_suppress(&intf->dev, old_suppress);
     }
     if (err == 0)
         set_bit(ifnum, &ps->ifclaimed);
     return err;
 }
 
 static int releaseintf(struct usb_dev_state *ps, unsigned int ifnum)
 {
     struct usb_device *dev;
     struct usb_interface *intf;
     int err;
 
     err = -EINVAL;
     if (ifnum >= 8*sizeof(ps->ifclaimed))
         return err;
     dev = ps->dev;
     intf = usb_ifnum_to_if(dev, ifnum);
     if (!intf)
         err = -ENOENT;
     else if (test_and_clear_bit(ifnum, &ps->ifclaimed)) {
         unsigned int old_suppress;
 
         /* suppress uevents while releasing interface */
         old_suppress = dev_get_uevent_suppress(&intf->dev);
         dev_set_uevent_suppress(&intf->dev, 1);
         usb_driver_release_interface(&usbfs_driver, intf);
         dev_set_uevent_suppress(&intf->dev, old_suppress);
         err = 0;
     }
     return err;
 }
 
 static int checkintf(struct usb_dev_state *ps, unsigned int ifnum)
 {
     if (ps->dev->state != USB_STATE_CONFIGURED)
         return -EHOSTUNREACH;
     if (ifnum >= 8*sizeof(ps->ifclaimed))
         return -EINVAL;
     if (test_bit(ifnum, &ps->ifclaimed))
         return 0;
     /* if not yet claimed, claim it for the driver */
     dev_warn(&ps->dev->dev, "usbfs: process %d (%s) did not claim "
          "interface %u before use\n", task_pid_nr(current),
          current->comm, ifnum);
     return claimintf(ps, ifnum);
 }
 
 static int findintfep(struct usb_device *dev, unsigned int ep)
 {
     unsigned int i, j, e;
     struct usb_interface *intf;
     struct usb_host_interface *alts;
     struct usb_endpoint_descriptor *endpt;
 
     if (ep & ~(USB_DIR_IN|0xf))
         return -EINVAL;
     if (!dev->actconfig)
         return -ESRCH;
     for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
         intf = dev->actconfig->interface[i];
         for (j = 0; j < intf->num_altsetting; j++) {
             alts = &intf->altsetting[j];
             for (e = 0; e < alts->desc.bNumEndpoints; e++) {
                 endpt = &alts->endpoint[e].desc;
                 if (endpt->bEndpointAddress == ep)
                     return alts->desc.bInterfaceNumber;
             }
         }
     }
     return -ENOENT;
 }
 
 static int check_ctrlrecip(struct usb_dev_state *ps, unsigned int requesttype,
                unsigned int request, unsigned int index)
 {
     int ret = 0;
     struct usb_host_interface *alt_setting;
 
     if (ps->dev->state != USB_STATE_UNAUTHENTICATED
      && ps->dev->state != USB_STATE_ADDRESS
      && ps->dev->state != USB_STATE_CONFIGURED)
         return -EHOSTUNREACH;
     if (USB_TYPE_VENDOR == (USB_TYPE_MASK & requesttype))
         return 0;
 
     /*
      * check for the special corner case 'get_device_id' in the printer
      * class specification, which we always want to allow as it is used
      * to query things like ink level, etc.
      */
     if (requesttype == 0xa1 && request == 0) {
         alt_setting = usb_find_alt_setting(ps->dev->actconfig,
                            index >> 8, index & 0xff);
         if (alt_setting
          && alt_setting->desc.bInterfaceClass == USB_CLASS_PRINTER)
             return 0;
     }
 
     index &= 0xff;
     switch (requesttype & USB_RECIP_MASK) {
     case USB_RECIP_ENDPOINT:
         if ((index & ~USB_DIR_IN) == 0)
             return 0;
         ret = findintfep(ps->dev, index);
         if (ret < 0) {
             /*
              * Some not fully compliant Win apps seem to get
              * index wrong and have the endpoint number here
              * rather than the endpoint address (with the
              * correct direction). Win does let this through,
              * so we'll not reject it here but leave it to
              * the device to not break KVM. But we warn.
              */
             ret = findintfep(ps->dev, index ^ 0x80);
             if (ret >= 0)
                 dev_info(&ps->dev->dev,
                     "%s: process %i (%s) requesting ep %02x but needs %02x\n",
                     __func__, task_pid_nr(current),
                     current->comm, index, index ^ 0x80);
         }
         if (ret >= 0)
             ret = checkintf(ps, ret);
         break;
 
     case USB_RECIP_INTERFACE:
         ret = checkintf(ps, index);
         break;
     }
     return ret;
 }
 
 static struct usb_host_endpoint *ep_to_host_endpoint(struct usb_device *dev,
                              unsigned char ep)
 {
     if (ep & USB_ENDPOINT_DIR_MASK)
         return dev->ep_in[ep & USB_ENDPOINT_NUMBER_MASK];
     else
         return dev->ep_out[ep & USB_ENDPOINT_NUMBER_MASK];
 }
 
 static int parse_usbdevfs_streams(struct usb_dev_state *ps,
                   struct usbdevfs_streams __user *streams,
                   unsigned int *num_streams_ret,
                   unsigned int *num_eps_ret,
                   struct usb_host_endpoint ***eps_ret,
                   struct usb_interface **intf_ret)
 {
     unsigned int i, num_streams, num_eps;
     struct usb_host_endpoint **eps;
     struct usb_interface *intf = NULL;
     unsigned char ep;
     int ifnum, ret;
 
     if (get_user(num_streams, &streams->num_streams) ||
         get_user(num_eps, &streams->num_eps))
         return -EFAULT;
 
     if (num_eps < 1 || num_eps > USB_MAXENDPOINTS)
         return -EINVAL;
 
     /* The XHCI controller allows max 2 ^ 16 streams */
     if (num_streams_ret && (num_streams < 2 || num_streams > 65536))
         return -EINVAL;
 
     eps = kmalloc_array(num_eps, sizeof(*eps), GFP_KERNEL);
     if (!eps)
         return -ENOMEM;
 
     for (i = 0; i < num_eps; i++) {
         if (get_user(ep, &streams->eps[i])) {
             ret = -EFAULT;
             goto error;
         }
         eps[i] = ep_to_host_endpoint(ps->dev, ep);
         if (!eps[i]) {
             ret = -EINVAL;
             goto error;
         }
 
         /* usb_alloc/free_streams operate on an usb_interface */
         ifnum = findintfep(ps->dev, ep);
         if (ifnum < 0) {
             ret = ifnum;
             goto error;
         }
 
         if (i == 0) {
             ret = checkintf(ps, ifnum);
             if (ret < 0)
                 goto error;
             intf = usb_ifnum_to_if(ps->dev, ifnum);
         } else {
             /* Verify all eps belong to the same interface */
             if (ifnum != intf->altsetting->desc.bInterfaceNumber) {
                 ret = -EINVAL;
                 goto error;
             }
         }
     }
 
     if (num_streams_ret)
         *num_streams_ret = num_streams;
     *num_eps_ret = num_eps;
     *eps_ret = eps;
     *intf_ret = intf;
 
     return 0;
 
 error:
     kfree(eps);
     return ret;
 }
 
 static struct usb_device *usbdev_lookup_by_devt(dev_t devt)
 {
     struct device *dev;
 
     dev = bus_find_device_by_devt(&usb_bus_type, devt);
     if (!dev)
         return NULL;
     return to_usb_device(dev);
 }
 
 /*
  * file operations
  */
 static int usbdev_open(struct inode *inode, struct file *file)
 {
     struct usb_device *dev = NULL;
     struct usb_dev_state *ps;
     int ret;
 
     ret = -ENOMEM;
     ps = kzalloc(sizeof(struct usb_dev_state), GFP_KERNEL);
     if (!ps)
         goto out_free_ps;
 
     ret = -ENODEV;
 
     /* usbdev device-node */
     if (imajor(inode) == USB_DEVICE_MAJOR)
         dev = usbdev_lookup_by_devt(inode->i_rdev);
     if (!dev)
         goto out_free_ps;
 
     usb_lock_device(dev);
     if (dev->state == USB_STATE_NOTATTACHED)
         goto out_unlock_device;
 
     ret = usb_autoresume_device(dev);
     if (ret)
         goto out_unlock_device;
 
     ps->dev = dev;
     ps->file = file;
     ps->interface_allowed_mask = 0xFFFFFFFF; /* 32 bits */
     spin_lock_init(&ps->lock);
     INIT_LIST_HEAD(&ps->list);
     INIT_LIST_HEAD(&ps->async_pending);
     INIT_LIST_HEAD(&ps->async_completed);
     INIT_LIST_HEAD(&ps->memory_list);
     init_waitqueue_head(&ps->wait);
     init_waitqueue_head(&ps->wait_for_resume);
     ps->disc_pid = get_pid(task_pid(current));
     ps->cred = get_current_cred();
     smp_wmb();
 
     /* Can't race with resume; the device is already active */
     list_add_tail(&ps->list, &dev->filelist);
     file->private_data = ps;
     usb_unlock_device(dev);
     snoop(&dev->dev, "opened by process %d: %s\n", task_pid_nr(current),
             current->comm);
     return ret;
 
  out_unlock_device:
     usb_unlock_device(dev);
     usb_put_dev(dev);
  out_free_ps:
     kfree(ps);
     return ret;
 }
 
 static int usbdev_release(struct inode *inode, struct file *file)
 {
     struct usb_dev_state *ps = file->private_data;
     struct usb_device *dev = ps->dev;
     unsigned int ifnum;
     struct async *as;
 
     usb_lock_device(dev);
     usb_hub_release_all_ports(dev, ps);
 
     /* Protect against simultaneous resume */
     mutex_lock(&usbfs_mutex);
     list_del_init(&ps->list);
     mutex_unlock(&usbfs_mutex);
 
     for (ifnum = 0; ps->ifclaimed && ifnum < 8*sizeof(ps->ifclaimed);
             ifnum++) {
         if (test_bit(ifnum, &ps->ifclaimed))
             releaseintf(ps, ifnum);
     }
     destroy_all_async(ps);
     if (!ps->suspend_allowed)
         usb_autosuspend_device(dev);
     usb_unlock_device(dev);
     usb_put_dev(dev);
     put_pid(ps->disc_pid);
     put_cred(ps->cred);
 
     as = async_getcompleted(ps);
     while (as) {
         free_async(as);
         as = async_getcompleted(ps);
     }
 
     kfree(ps);
     return 0;
 }
 
 static void usbfs_blocking_completion(struct urb *urb)
 {
     complete((struct completion *) urb->context);
 }
 
 /*
  * Much like usb_start_wait_urb, but returns status separately from
  * actual_length and uses a killable wait.
  */
 static int usbfs_start_wait_urb(struct urb *urb, int timeout,
         unsigned int *actlen)
 {
     DECLARE_COMPLETION_ONSTACK(ctx);
     unsigned long expire;
     int rc;
 
     urb->context = &ctx;
     urb->complete = usbfs_blocking_completion;
     *actlen = 0;
     rc = usb_submit_urb(urb, GFP_KERNEL);
     if (unlikely(rc))
         return rc;
 
     expire = (timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT);
     rc = wait_for_completion_killable_timeout(&ctx, expire);
     if (rc <= 0) {
         usb_kill_urb(urb);
         *actlen = urb->actual_length;
         if (urb->status != -ENOENT)
             ;   /* Completed before it was killed */
         else if (rc < 0)
             return -EINTR;
         else
             return -ETIMEDOUT;
     }
     *actlen = urb->actual_length;
     return urb->status;
 }
 
 static int do_proc_control(struct usb_dev_state *ps,
         struct usbdevfs_ctrltransfer *ctrl)
 {
     struct usb_device *dev = ps->dev;
     unsigned int tmo;
     unsigned char *tbuf;
     unsigned int wLength, actlen;
     int i, pipe, ret;
     struct urb *urb = NULL;
     struct usb_ctrlrequest *dr = NULL;
 
     ret = check_ctrlrecip(ps, ctrl->bRequestType, ctrl->bRequest,
                   ctrl->wIndex);
     if (ret)
         return ret;
     wLength = ctrl->wLength;    /* To suppress 64k PAGE_SIZE warning */
     if (wLength > PAGE_SIZE)
         return -EINVAL;
     ret = usbfs_increase_memory_usage(PAGE_SIZE + sizeof(struct urb) +
             sizeof(struct usb_ctrlrequest));
     if (ret)
         return ret;
 
     ret = -ENOMEM;
     tbuf = (unsigned char *)__get_free_page(GFP_KERNEL);
     if (!tbuf)
         goto done;
     urb = usb_alloc_urb(0, GFP_NOIO);
     if (!urb)
         goto done;
     dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
     if (!dr)
         goto done;
 
     dr->bRequestType = ctrl->bRequestType;
     dr->bRequest = ctrl->bRequest;
     dr->wValue = cpu_to_le16(ctrl->wValue);
     dr->wIndex = cpu_to_le16(ctrl->wIndex);
     dr->wLength = cpu_to_le16(ctrl->wLength);
 
     tmo = ctrl->timeout;
     snoop(&dev->dev, "control urb: bRequestType=%02x "
         "bRequest=%02x wValue=%04x "
         "wIndex=%04x wLength=%04x\n",
         ctrl->bRequestType, ctrl->bRequest, ctrl->wValue,
         ctrl->wIndex, ctrl->wLength);
 
     if ((ctrl->bRequestType & USB_DIR_IN) && wLength) {
         pipe = usb_rcvctrlpipe(dev, 0);
         usb_fill_control_urb(urb, dev, pipe, (unsigned char *) dr, tbuf,
                 wLength, NULL, NULL);
         snoop_urb(dev, NULL, pipe, wLength, tmo, SUBMIT, NULL, 0);
 
         usb_unlock_device(dev);
         i = usbfs_start_wait_urb(urb, tmo, &actlen);
 
         /* Linger a bit, prior to the next control message. */
         if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
             msleep(200);
         usb_lock_device(dev);
         snoop_urb(dev, NULL, pipe, actlen, i, COMPLETE, tbuf, actlen);
         if (!i && actlen) {
             if (copy_to_user(ctrl->data, tbuf, actlen)) {
                 ret = -EFAULT;
                 goto done;
             }
         }
     } else {
         if (wLength) {
             if (copy_from_user(tbuf, ctrl->data, wLength)) {
                 ret = -EFAULT;
                 goto done;
             }
         }
         pipe = usb_sndctrlpipe(dev, 0);
         usb_fill_control_urb(urb, dev, pipe, (unsigned char *) dr, tbuf,
                 wLength, NULL, NULL);
         snoop_urb(dev, NULL, pipe, wLength, tmo, SUBMIT, tbuf, wLength);
 
         usb_unlock_device(dev);
         i = usbfs_start_wait_urb(urb, tmo, &actlen);
 
         /* Linger a bit, prior to the next control message. */
         if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
             msleep(200);
         usb_lock_device(dev);
         snoop_urb(dev, NULL, pipe, actlen, i, COMPLETE, NULL, 0);
     }
     if (i < 0 && i != -EPIPE) {
         dev_printk(KERN_DEBUG, &dev->dev, "usbfs: USBDEVFS_CONTROL "
                "failed cmd %s rqt %u rq %u len %u ret %d\n",
                current->comm, ctrl->bRequestType, ctrl->bRequest,
                ctrl->wLength, i);
     }
     ret = (i < 0 ? i : actlen);
 
  done:
     kfree(dr);
     usb_free_urb(urb);
     free_page((unsigned long) tbuf);
     usbfs_decrease_memory_usage(PAGE_SIZE + sizeof(struct urb) +
             sizeof(struct usb_ctrlrequest));
     return ret;
 }
 
 static int proc_control(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_ctrltransfer ctrl;
 
     if (copy_from_user(&ctrl, arg, sizeof(ctrl)))
         return -EFAULT;
     return do_proc_control(ps, &ctrl);
 }
 
 static int do_proc_bulk(struct usb_dev_state *ps,
         struct usbdevfs_bulktransfer *bulk)
 {
     struct usb_device *dev = ps->dev;
     unsigned int tmo, len1, len2, pipe;
     unsigned char *tbuf;
     int i, ret;
     struct urb *urb = NULL;
     struct usb_host_endpoint *ep;
 
     ret = findintfep(ps->dev, bulk->ep);
     if (ret < 0)
         return ret;
     ret = checkintf(ps, ret);
     if (ret)
         return ret;
 
     len1 = bulk->len;
     if (len1 < 0 || len1 >= (INT_MAX - sizeof(struct urb)))
         return -EINVAL;
 
     if (bulk->ep & USB_DIR_IN)
         pipe = usb_rcvbulkpipe(dev, bulk->ep & 0x7f);
     else
         pipe = usb_sndbulkpipe(dev, bulk->ep & 0x7f);
     ep = usb_pipe_endpoint(dev, pipe);
     if (!ep || !usb_endpoint_maxp(&ep->desc))
         return -EINVAL;
     ret = usbfs_increase_memory_usage(len1 + sizeof(struct urb));
     if (ret)
         return ret;
 
     /*
      * len1 can be almost arbitrarily large.  Don't WARN if it's
      * too big, just fail the request.
      */
     ret = -ENOMEM;
     tbuf = kmalloc(len1, GFP_KERNEL | __GFP_NOWARN);
     if (!tbuf)
         goto done;
     urb = usb_alloc_urb(0, GFP_KERNEL);
     if (!urb)
         goto done;
 
     if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
             USB_ENDPOINT_XFER_INT) {
         pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
         usb_fill_int_urb(urb, dev, pipe, tbuf, len1,
                 NULL, NULL, ep->desc.bInterval);
     } else {
         usb_fill_bulk_urb(urb, dev, pipe, tbuf, len1, NULL, NULL);
     }
 
     tmo = bulk->timeout;
     if (bulk->ep & 0x80) {
         snoop_urb(dev, NULL, pipe, len1, tmo, SUBMIT, NULL, 0);
 
         usb_unlock_device(dev);
         i = usbfs_start_wait_urb(urb, tmo, &len2);
         usb_lock_device(dev);
         snoop_urb(dev, NULL, pipe, len2, i, COMPLETE, tbuf, len2);
 
         if (!i && len2) {
             if (copy_to_user(bulk->data, tbuf, len2)) {
                 ret = -EFAULT;
                 goto done;
             }
         }
     } else {
         if (len1) {
             if (copy_from_user(tbuf, bulk->data, len1)) {
                 ret = -EFAULT;
                 goto done;
             }
         }
         snoop_urb(dev, NULL, pipe, len1, tmo, SUBMIT, tbuf, len1);
 
         usb_unlock_device(dev);
         i = usbfs_start_wait_urb(urb, tmo, &len2);
         usb_lock_device(dev);
         snoop_urb(dev, NULL, pipe, len2, i, COMPLETE, NULL, 0);
     }
     ret = (i < 0 ? i : len2);
  done:
     usb_free_urb(urb);
     kfree(tbuf);
     usbfs_decrease_memory_usage(len1 + sizeof(struct urb));
     return ret;
 }
 
 static int proc_bulk(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_bulktransfer bulk;
 
     if (copy_from_user(&bulk, arg, sizeof(bulk)))
         return -EFAULT;
     return do_proc_bulk(ps, &bulk);
 }
 
 static void check_reset_of_active_ep(struct usb_device *udev,
         unsigned int epnum, char *ioctl_name)
 {
     struct usb_host_endpoint **eps;
     struct usb_host_endpoint *ep;
 
     eps = (epnum & USB_DIR_IN) ? udev->ep_in : udev->ep_out;
     ep = eps[epnum & 0x0f];
     if (ep && !list_empty(&ep->urb_list))
         dev_warn(&udev->dev, "Process %d (%s) called USBDEVFS_%s for active endpoint 0x%02x\n",
                 task_pid_nr(current), current->comm,
                 ioctl_name, epnum);
 }
 
 static int proc_resetep(struct usb_dev_state *ps, void __user *arg)
 {
     unsigned int ep;
     int ret;
 
     if (get_user(ep, (unsigned int __user *)arg))
         return -EFAULT;
     ret = findintfep(ps->dev, ep);
     if (ret < 0)
         return ret;
     ret = checkintf(ps, ret);
     if (ret)
         return ret;
     check_reset_of_active_ep(ps->dev, ep, "RESETEP");
     usb_reset_endpoint(ps->dev, ep);
     return 0;
 }
 
 static int proc_clearhalt(struct usb_dev_state *ps, void __user *arg)
 {
     unsigned int ep;
     int pipe;
     int ret;
 
     if (get_user(ep, (unsigned int __user *)arg))
         return -EFAULT;
     ret = findintfep(ps->dev, ep);
     if (ret < 0)
         return ret;
     ret = checkintf(ps, ret);
     if (ret)
         return ret;
     check_reset_of_active_ep(ps->dev, ep, "CLEAR_HALT");
     if (ep & USB_DIR_IN)
         pipe = usb_rcvbulkpipe(ps->dev, ep & 0x7f);
     else
         pipe = usb_sndbulkpipe(ps->dev, ep & 0x7f);
 
     return usb_clear_halt(ps->dev, pipe);
 }
 
 static int proc_getdriver(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_getdriver gd;
     struct usb_interface *intf;
     int ret;
 
     if (copy_from_user(&gd, arg, sizeof(gd)))
         return -EFAULT;
     intf = usb_ifnum_to_if(ps->dev, gd.interface);
     if (!intf || !intf->dev.driver)
         ret = -ENODATA;
     else {
         strlcpy(gd.driver, intf->dev.driver->name,
                 sizeof(gd.driver));
         ret = (copy_to_user(arg, &gd, sizeof(gd)) ? -EFAULT : 0);
     }
     return ret;
 }
 
 static int proc_connectinfo(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_connectinfo ci;
 
     memset(&ci, 0, sizeof(ci));
     ci.devnum = ps->dev->devnum;
     ci.slow = ps->dev->speed == USB_SPEED_LOW;
 
     if (copy_to_user(arg, &ci, sizeof(ci)))
         return -EFAULT;
     return 0;
 }
 
 static int proc_conninfo_ex(struct usb_dev_state *ps,
                 void __user *arg, size_t size)
 {
     struct usbdevfs_conninfo_ex ci;
     struct usb_device *udev = ps->dev;
 
     if (size < sizeof(ci.size))
         return -EINVAL;
 
     memset(&ci, 0, sizeof(ci));
     ci.size = sizeof(ci);
     ci.busnum = udev->bus->busnum;
     ci.devnum = udev->devnum;
     ci.speed = udev->speed;
 
     while (udev && udev->portnum != 0) {
         if (++ci.num_ports <= ARRAY_SIZE(ci.ports))
             ci.ports[ARRAY_SIZE(ci.ports) - ci.num_ports] =
                     udev->portnum;
         udev = udev->parent;
     }
 
     if (ci.num_ports < ARRAY_SIZE(ci.ports))
         memmove(&ci.ports[0],
             &ci.ports[ARRAY_SIZE(ci.ports) - ci.num_ports],
             ci.num_ports);
 
     if (copy_to_user(arg, &ci, min(sizeof(ci), size)))
         return -EFAULT;
 
     return 0;
 }
 
 static int proc_resetdevice(struct usb_dev_state *ps)
 {
     struct usb_host_config *actconfig = ps->dev->actconfig;
     struct usb_interface *interface;
     int i, number;
 
     /* Don't allow a device reset if the process has dropped the
      * privilege to do such things and any of the interfaces are
      * currently claimed.
      */
     if (ps->privileges_dropped && actconfig) {
         for (i = 0; i < actconfig->desc.bNumInterfaces; ++i) {
             interface = actconfig->interface[i];
             number = interface->cur_altsetting->desc.bInterfaceNumber;
             if (usb_interface_claimed(interface) &&
                     !test_bit(number, &ps->ifclaimed)) {
                 dev_warn(&ps->dev->dev,
                     "usbfs: interface %d claimed by %s while '%s' resets device\n",
                     number, interface->dev.driver->name, current->comm);
                 return -EACCES;
             }
         }
     }
 
     return usb_reset_device(ps->dev);
 }
 
 static int proc_setintf(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_setinterface setintf;
     int ret;
 
     if (copy_from_user(&setintf, arg, sizeof(setintf)))
         return -EFAULT;
     ret = checkintf(ps, setintf.interface);
     if (ret)
         return ret;
 
     destroy_async_on_interface(ps, setintf.interface);
 
     return usb_set_interface(ps->dev, setintf.interface,
             setintf.altsetting);
 }
 
 static int proc_setconfig(struct usb_dev_state *ps, void __user *arg)
 {
     int u;
     int status = 0;
     struct usb_host_config *actconfig;
 
     if (get_user(u, (int __user *)arg))
         return -EFAULT;
 
     actconfig = ps->dev->actconfig;
 
     /* Don't touch the device if any interfaces are claimed.
      * It could interfere with other drivers' operations, and if
      * an interface is claimed by usbfs it could easily deadlock.
      */
     if (actconfig) {
         int i;
 
         for (i = 0; i < actconfig->desc.bNumInterfaces; ++i) {
             if (usb_interface_claimed(actconfig->interface[i])) {
                 dev_warn(&ps->dev->dev,
                     "usbfs: interface %d claimed by %s "
                     "while '%s' sets config #%d\n",
                     actconfig->interface[i]
                         ->cur_altsetting
                         ->desc.bInterfaceNumber,
                     actconfig->interface[i]
                         ->dev.driver->name,
                     current->comm, u);
                 status = -EBUSY;
                 break;
             }
         }
     }
 
     /* SET_CONFIGURATION is often abused as a "cheap" driver reset,
      * so avoid usb_set_configuration()'s kick to sysfs
      */
     if (status == 0) {
         if (actconfig && actconfig->desc.bConfigurationValue == u)
             status = usb_reset_configuration(ps->dev);
         else
             status = usb_set_configuration(ps->dev, u);
     }
 
     return status;
 }
 
 static struct usb_memory *
 find_memory_area(struct usb_dev_state *ps, const struct usbdevfs_urb *uurb)
 {
     struct usb_memory *usbm = NULL, *iter;
     unsigned long flags;
     unsigned long uurb_start = (unsigned long)uurb->buffer;
 
     spin_lock_irqsave(&ps->lock, flags);
     list_for_each_entry(iter, &ps->memory_list, memlist) {
         if (uurb_start >= iter->vm_start &&
                 uurb_start < iter->vm_start + iter->size) {
             if (uurb->buffer_length > iter->vm_start + iter->size -
                     uurb_start) {
                 usbm = ERR_PTR(-EINVAL);
             } else {
                 usbm = iter;
                 usbm->urb_use_count++;
             }
             break;
         }
     }
     spin_unlock_irqrestore(&ps->lock, flags);
     return usbm;
 }
 
 static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb,
             struct usbdevfs_iso_packet_desc __user *iso_frame_desc,
             void __user *arg, sigval_t userurb_sigval)
 {
     struct usbdevfs_iso_packet_desc *isopkt = NULL;
     struct usb_host_endpoint *ep;
     struct async *as = NULL;
     struct usb_ctrlrequest *dr = NULL;
     unsigned int u, totlen, isofrmlen;
     int i, ret, num_sgs = 0, ifnum = -1;
     int number_of_packets = 0;
     unsigned int stream_id = 0;
     void *buf;
     bool is_in;
     bool allow_short = false;
     bool allow_zero = false;
     unsigned long mask =    USBDEVFS_URB_SHORT_NOT_OK |
                 USBDEVFS_URB_BULK_CONTINUATION |
                 USBDEVFS_URB_NO_FSBR |
                 USBDEVFS_URB_ZERO_PACKET |
                 USBDEVFS_URB_NO_INTERRUPT;
     /* USBDEVFS_URB_ISO_ASAP is a special case */
     if (uurb->type == USBDEVFS_URB_TYPE_ISO)
         mask |= USBDEVFS_URB_ISO_ASAP;
 
     if (uurb->flags & ~mask)
             return -EINVAL;
 
     if ((unsigned int)uurb->buffer_length >= USBFS_XFER_MAX)
         return -EINVAL;
     if (uurb->buffer_length > 0 && !uurb->buffer)
         return -EINVAL;
     if (!(uurb->type == USBDEVFS_URB_TYPE_CONTROL &&
         (uurb->endpoint & ~USB_ENDPOINT_DIR_MASK) == 0)) {
         ifnum = findintfep(ps->dev, uurb->endpoint);
         if (ifnum < 0)
             return ifnum;
         ret = checkintf(ps, ifnum);
         if (ret)
             return ret;
     }
     ep = ep_to_host_endpoint(ps->dev, uurb->endpoint);
     if (!ep)
         return -ENOENT;
     is_in = (uurb->endpoint & USB_ENDPOINT_DIR_MASK) != 0;
 
     u = 0;
     switch (uurb->type) {
     case USBDEVFS_URB_TYPE_CONTROL:
         if (!usb_endpoint_xfer_control(&ep->desc))
             return -EINVAL;
         /* min 8 byte setup packet */
         if (uurb->buffer_length < 8)
             return -EINVAL;
         dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
         if (!dr)
             return -ENOMEM;
         if (copy_from_user(dr, uurb->buffer, 8)) {
             ret = -EFAULT;
             goto error;
         }
         if (uurb->buffer_length < (le16_to_cpu(dr->wLength) + 8)) {
             ret = -EINVAL;
             goto error;
         }
         ret = check_ctrlrecip(ps, dr->bRequestType, dr->bRequest,
                       le16_to_cpu(dr->wIndex));
         if (ret)
             goto error;
         uurb->buffer_length = le16_to_cpu(dr->wLength);
         uurb->buffer += 8;
         if ((dr->bRequestType & USB_DIR_IN) && uurb->buffer_length) {
             is_in = true;
             uurb->endpoint |= USB_DIR_IN;
         } else {
             is_in = false;
             uurb->endpoint &= ~USB_DIR_IN;
         }
         if (is_in)
             allow_short = true;
         snoop(&ps->dev->dev, "control urb: bRequestType=%02x "
             "bRequest=%02x wValue=%04x "
             "wIndex=%04x wLength=%04x\n",
             dr->bRequestType, dr->bRequest,
             __le16_to_cpu(dr->wValue),
             __le16_to_cpu(dr->wIndex),
             __le16_to_cpu(dr->wLength));
         u = sizeof(struct usb_ctrlrequest);
         break;
 
     case USBDEVFS_URB_TYPE_BULK:
         if (!is_in)
             allow_zero = true;
         else
             allow_short = true;
         switch (usb_endpoint_type(&ep->desc)) {
         case USB_ENDPOINT_XFER_CONTROL:
         case USB_ENDPOINT_XFER_ISOC:
             return -EINVAL;
         case USB_ENDPOINT_XFER_INT:
             /* allow single-shot interrupt transfers */
             uurb->type = USBDEVFS_URB_TYPE_INTERRUPT;
             goto interrupt_urb;
         }
         num_sgs = DIV_ROUND_UP(uurb->buffer_length, USB_SG_SIZE);
         if (num_sgs == 1 || num_sgs > ps->dev->bus->sg_tablesize)
             num_sgs = 0;
         if (ep->streams)
             stream_id = uurb->stream_id;
         break;
 
     case USBDEVFS_URB_TYPE_INTERRUPT:
         if (!usb_endpoint_xfer_int(&ep->desc))
             return -EINVAL;
  interrupt_urb:
         if (!is_in)
             allow_zero = true;
         else
             allow_short = true;
         break;
 
     case USBDEVFS_URB_TYPE_ISO:
         /* arbitrary limit */
         if (uurb->number_of_packets < 1 ||
             uurb->number_of_packets > 128)
             return -EINVAL;
         if (!usb_endpoint_xfer_isoc(&ep->desc))
             return -EINVAL;
         number_of_packets = uurb->number_of_packets;
         isofrmlen = sizeof(struct usbdevfs_iso_packet_desc) *
                    number_of_packets;
         isopkt = memdup_user(iso_frame_desc, isofrmlen);
         if (IS_ERR(isopkt)) {
             ret = PTR_ERR(isopkt);
             isopkt = NULL;
             goto error;
         }
         for (totlen = u = 0; u < number_of_packets; u++) {
             /*
              * arbitrary limit need for USB 3.1 Gen2
              * sizemax: 96 DPs at SSP, 96 * 1024 = 98304
              */
             if (isopkt[u].length > 98304) {
                 ret = -EINVAL;
                 goto error;
             }
             totlen += isopkt[u].length;
         }
         u *= sizeof(struct usb_iso_packet_descriptor);
         uurb->buffer_length = totlen;
         break;
 
     default:
         return -EINVAL;
     }
 
     if (uurb->buffer_length > 0 &&
             !access_ok(uurb->buffer, uurb->buffer_length)) {
         ret = -EFAULT;
         goto error;
     }
     as = alloc_async(number_of_packets);
     if (!as) {
         ret = -ENOMEM;
         goto error;
     }
 
     as->usbm = find_memory_area(ps, uurb);
     if (IS_ERR(as->usbm)) {
         ret = PTR_ERR(as->usbm);
         as->usbm = NULL;
         goto error;
     }
 
     /* do not use SG buffers when memory mapped segments
      * are in use
      */
     if (as->usbm)
         num_sgs = 0;
 
     u += sizeof(struct async) + sizeof(struct urb) +
          (as->usbm ? 0 : uurb->buffer_length) +
          num_sgs * sizeof(struct scatterlist);
     ret = usbfs_increase_memory_usage(u);
     if (ret)
         goto error;
     as->mem_usage = u;
 
     if (num_sgs) {
         as->urb->sg = kmalloc_array(num_sgs,
                         sizeof(struct scatterlist),
                         GFP_KERNEL | __GFP_NOWARN);
         if (!as->urb->sg) {
             ret = -ENOMEM;
             goto error;
         }
         as->urb->num_sgs = num_sgs;
         sg_init_table(as->urb->sg, as->urb->num_sgs);
 
         totlen = uurb->buffer_length;
         for (i = 0; i < as->urb->num_sgs; i++) {
             u = (totlen > USB_SG_SIZE) ? USB_SG_SIZE : totlen;
             buf = kmalloc(u, GFP_KERNEL);
             if (!buf) {
                 ret = -ENOMEM;
                 goto error;
             }
             sg_set_buf(&as->urb->sg[i], buf, u);
 
             if (!is_in) {
                 if (copy_from_user(buf, uurb->buffer, u)) {
                     ret = -EFAULT;
                     goto error;
                 }
                 uurb->buffer += u;
             }
             totlen -= u;
         }
     } else if (uurb->buffer_length > 0) {
         if (as->usbm) {
             unsigned long uurb_start = (unsigned long)uurb->buffer;
 
             as->urb->transfer_buffer = as->usbm->mem +
                     (uurb_start - as->usbm->vm_start);
         } else {
             as->urb->transfer_buffer = kmalloc(uurb->buffer_length,
                     GFP_KERNEL | __GFP_NOWARN);
             if (!as->urb->transfer_buffer) {
                 ret = -ENOMEM;
                 goto error;
             }
             if (!is_in) {
                 if (copy_from_user(as->urb->transfer_buffer,
                            uurb->buffer,
                            uurb->buffer_length)) {
                     ret = -EFAULT;
                     goto error;
                 }
             } else if (uurb->type == USBDEVFS_URB_TYPE_ISO) {
                 /*
                  * Isochronous input data may end up being
                  * discontiguous if some of the packets are
                  * short. Clear the buffer so that the gaps
                  * don't leak kernel data to userspace.
                  */
                 memset(as->urb->transfer_buffer, 0,
                         uurb->buffer_length);
             }
         }
     }
     as->urb->dev = ps->dev;
     as->urb->pipe = (uurb->type << 30) |
             __create_pipe(ps->dev, uurb->endpoint & 0xf) |
             (uurb->endpoint & USB_DIR_IN);
 
     /* This tedious sequence is necessary because the URB_* flags
      * are internal to the kernel and subject to change, whereas
      * the USBDEVFS_URB_* flags are a user API and must not be changed.
      */
     u = (is_in ? URB_DIR_IN : URB_DIR_OUT);
     if (uurb->flags & USBDEVFS_URB_ISO_ASAP)
         u |= URB_ISO_ASAP;
     if (allow_short && uurb->flags & USBDEVFS_URB_SHORT_NOT_OK)
         u |= URB_SHORT_NOT_OK;
     if (allow_zero && uurb->flags & USBDEVFS_URB_ZERO_PACKET)
         u |= URB_ZERO_PACKET;
     if (uurb->flags & USBDEVFS_URB_NO_INTERRUPT)
         u |= URB_NO_INTERRUPT;
     as->urb->transfer_flags = u;
 
     if (!allow_short && uurb->flags & USBDEVFS_URB_SHORT_NOT_OK)
         dev_warn(&ps->dev->dev, "Requested nonsensical USBDEVFS_URB_SHORT_NOT_OK.\n");
     if (!allow_zero && uurb->flags & USBDEVFS_URB_ZERO_PACKET)
         dev_warn(&ps->dev->dev, "Requested nonsensical USBDEVFS_URB_ZERO_PACKET.\n");
 
     as->urb->transfer_buffer_length = uurb->buffer_length;
     as->urb->setup_packet = (unsigned char *)dr;
     dr = NULL;
     as->urb->start_frame = uurb->start_frame;
     as->urb->number_of_packets = number_of_packets;
     as->urb->stream_id = stream_id;
 
     if (ep->desc.bInterval) {
         if (uurb->type == USBDEVFS_URB_TYPE_ISO ||
                 ps->dev->speed == USB_SPEED_HIGH ||
                 ps->dev->speed >= USB_SPEED_SUPER)
             as->urb->interval = 1 <<
                     min(15, ep->desc.bInterval - 1);
         else
             as->urb->interval = ep->desc.bInterval;
     }
 
     as->urb->context = as;
     as->urb->complete = async_completed;
     for (totlen = u = 0; u < number_of_packets; u++) {
         as->urb->iso_frame_desc[u].offset = totlen;
         as->urb->iso_frame_desc[u].length = isopkt[u].length;
         totlen += isopkt[u].length;
     }
     kfree(isopkt);
     isopkt = NULL;
     as->ps = ps;
     as->userurb = arg;
     as->userurb_sigval = userurb_sigval;
     if (as->usbm) {
         unsigned long uurb_start = (unsigned long)uurb->buffer;
 
         as->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
         as->urb->transfer_dma = as->usbm->dma_handle +
                 (uurb_start - as->usbm->vm_start);
     } else if (is_in && uurb->buffer_length > 0)
         as->userbuffer = uurb->buffer;
     as->signr = uurb->signr;
     as->ifnum = ifnum;
     as->pid = get_pid(task_pid(current));
     as->cred = get_current_cred();
     snoop_urb(ps->dev, as->userurb, as->urb->pipe,
             as->urb->transfer_buffer_length, 0, SUBMIT,
             NULL, 0);
     if (!is_in)
         snoop_urb_data(as->urb, as->urb->transfer_buffer_length);
 
     async_newpending(as);
 
     if (usb_endpoint_xfer_bulk(&ep->desc)) {
         spin_lock_irq(&ps->lock);
 
         /* Not exactly the endpoint address; the direction bit is
          * shifted to the 0x10 position so that the value will be
          * between 0 and 31.
          */
         as->bulk_addr = usb_endpoint_num(&ep->desc) |
             ((ep->desc.bEndpointAddress & USB_ENDPOINT_DIR_MASK)
                 >> 3);
 
         /* If this bulk URB is the start of a new transfer, re-enable
          * the endpoint.  Otherwise mark it as a continuation URB.
          */
         if (uurb->flags & USBDEVFS_URB_BULK_CONTINUATION)
             as->bulk_status = AS_CONTINUATION;
         else
             ps->disabled_bulk_eps &= ~(1 << as->bulk_addr);
 
         /* Don't accept continuation URBs if the endpoint is
          * disabled because of an earlier error.
          */
         if (ps->disabled_bulk_eps & (1 << as->bulk_addr))
             ret = -EREMOTEIO;
         else
             ret = usb_submit_urb(as->urb, GFP_ATOMIC);
         spin_unlock_irq(&ps->lock);
     } else {
         ret = usb_submit_urb(as->urb, GFP_KERNEL);
     }
 
     if (ret) {
         dev_printk(KERN_DEBUG, &ps->dev->dev,
                "usbfs: usb_submit_urb returned %d\n", ret);
         snoop_urb(ps->dev, as->userurb, as->urb->pipe,
                 0, ret, COMPLETE, NULL, 0);
         async_removepending(as);
         goto error;
     }
     return 0;
 
  error:
     kfree(isopkt);
     kfree(dr);
     if (as)
         free_async(as);
     return ret;
 }
 
 static int proc_submiturb(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_urb uurb;
     sigval_t userurb_sigval;
 
     if (copy_from_user(&uurb, arg, sizeof(uurb)))
         return -EFAULT;
 
     memset(&userurb_sigval, 0, sizeof(userurb_sigval));
     userurb_sigval.sival_ptr = arg;
 
     return proc_do_submiturb(ps, &uurb,
             (((struct usbdevfs_urb __user *)arg)->iso_frame_desc),
             arg, userurb_sigval);
 }
 
 static int proc_unlinkurb(struct usb_dev_state *ps, void __user *arg)
 {
     struct urb *urb;
     struct async *as;
     unsigned long flags;
 
     spin_lock_irqsave(&ps->lock, flags);
     as = async_getpending(ps, arg);
     if (!as) {
         spin_unlock_irqrestore(&ps->lock, flags);
         return -EINVAL;
     }
 
     urb = as->urb;
     usb_get_urb(urb);
     spin_unlock_irqrestore(&ps->lock, flags);
 
     usb_kill_urb(urb);
     usb_put_urb(urb);
 
     return 0;
 }
 
 static void compute_isochronous_actual_length(struct urb *urb)
 {
     unsigned int i;
 
     if (urb->number_of_packets > 0) {
         urb->actual_length = 0;
         for (i = 0; i < urb->number_of_packets; i++)
             urb->actual_length +=
                     urb->iso_frame_desc[i].actual_length;
     }
 }
 
 static int processcompl(struct async *as, void __user * __user *arg)
 {
     struct urb *urb = as->urb;
     struct usbdevfs_urb __user *userurb = as->userurb;
     void __user *addr = as->userurb;
     unsigned int i;
 
     compute_isochronous_actual_length(urb);
     if (as->userbuffer && urb->actual_length) {
         if (copy_urb_data_to_user(as->userbuffer, urb))
             goto err_out;
     }
     if (put_user(as->status, &userurb->status))
         goto err_out;
     if (put_user(urb->actual_length, &userurb->actual_length))
         goto err_out;
     if (put_user(urb->error_count, &userurb->error_count))
         goto err_out;
 
     if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
         for (i = 0; i < urb->number_of_packets; i++) {
             if (put_user(urb->iso_frame_desc[i].actual_length,
                      &userurb->iso_frame_desc[i].actual_length))
                 goto err_out;
             if (put_user(urb->iso_frame_desc[i].status,
                      &userurb->iso_frame_desc[i].status))
                 goto err_out;
         }
     }
 
     if (put_user(addr, (void __user * __user *)arg))
         return -EFAULT;
     return 0;
 
 err_out:
     return -EFAULT;
 }
 
 static struct async *reap_as(struct usb_dev_state *ps)
 {
     DECLARE_WAITQUEUE(wait, current);
     struct async *as = NULL;
     struct usb_device *dev = ps->dev;
 
     add_wait_queue(&ps->wait, &wait);
     for (;;) {
         __set_current_state(TASK_INTERRUPTIBLE);
         as = async_getcompleted(ps);
         if (as || !connected(ps))
             break;
         if (signal_pending(current))
             break;
         usb_unlock_device(dev);
         schedule();
         usb_lock_device(dev);
     }
     remove_wait_queue(&ps->wait, &wait);
     set_current_state(TASK_RUNNING);
     return as;
 }
 
 static int proc_reapurb(struct usb_dev_state *ps, void __user *arg)
 {
     struct async *as = reap_as(ps);
 
     if (as) {
         int retval;
 
         snoop(&ps->dev->dev, "reap %px\n", as->userurb);
         retval = processcompl(as, (void __user * __user *)arg);
         free_async(as);
         return retval;
     }
     if (signal_pending(current))
         return -EINTR;
     return -ENODEV;
 }
 
 static int proc_reapurbnonblock(struct usb_dev_state *ps, void __user *arg)
 {
     int retval;
     struct async *as;
 
     as = async_getcompleted(ps);
     if (as) {
         snoop(&ps->dev->dev, "reap %px\n", as->userurb);
         retval = processcompl(as, (void __user * __user *)arg);
         free_async(as);
     } else {
         retval = (connected(ps) ? -EAGAIN : -ENODEV);
     }
     return retval;
 }
 
 #ifdef CONFIG_COMPAT
 static int proc_control_compat(struct usb_dev_state *ps,
                 struct usbdevfs_ctrltransfer32 __user *p32)
 {
     struct usbdevfs_ctrltransfer ctrl;
     u32 udata;
 
     if (copy_from_user(&ctrl, p32, sizeof(*p32) - sizeof(compat_caddr_t)) ||
         get_user(udata, &p32->data))
         return -EFAULT;
     ctrl.data = compat_ptr(udata);
     return do_proc_control(ps, &ctrl);
 }
 
 static int proc_bulk_compat(struct usb_dev_state *ps,
             struct usbdevfs_bulktransfer32 __user *p32)
 {
     struct usbdevfs_bulktransfer bulk;
     compat_caddr_t addr;
 
     if (get_user(bulk.ep, &p32->ep) ||
         get_user(bulk.len, &p32->len) ||
         get_user(bulk.timeout, &p32->timeout) ||
         get_user(addr, &p32->data))
         return -EFAULT;
     bulk.data = compat_ptr(addr);
     return do_proc_bulk(ps, &bulk);
 }
 
 static int proc_disconnectsignal_compat(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_disconnectsignal32 ds;
 
     if (copy_from_user(&ds, arg, sizeof(ds)))
         return -EFAULT;
     ps->discsignr = ds.signr;
     ps->disccontext.sival_int = ds.context;
     return 0;
 }
 
 static int get_urb32(struct usbdevfs_urb *kurb,
              struct usbdevfs_urb32 __user *uurb)
 {
     struct usbdevfs_urb32 urb32;
     if (copy_from_user(&urb32, uurb, sizeof(*uurb)))
         return -EFAULT;
     kurb->type = urb32.type;
     kurb->endpoint = urb32.endpoint;
     kurb->status = urb32.status;
     kurb->flags = urb32.flags;
     kurb->buffer = compat_ptr(urb32.buffer);
     kurb->buffer_length = urb32.buffer_length;
     kurb->actual_length = urb32.actual_length;
     kurb->start_frame = urb32.start_frame;
     kurb->number_of_packets = urb32.number_of_packets;
     kurb->error_count = urb32.error_count;
     kurb->signr = urb32.signr;
     kurb->usercontext = compat_ptr(urb32.usercontext);
     return 0;
 }
 
 static int proc_submiturb_compat(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_urb uurb;
     sigval_t userurb_sigval;
 
     if (get_urb32(&uurb, (struct usbdevfs_urb32 __user *)arg))
         return -EFAULT;
 
     memset(&userurb_sigval, 0, sizeof(userurb_sigval));
     userurb_sigval.sival_int = ptr_to_compat(arg);
 
     return proc_do_submiturb(ps, &uurb,
             ((struct usbdevfs_urb32 __user *)arg)->iso_frame_desc,
             arg, userurb_sigval);
 }
 
 static int processcompl_compat(struct async *as, void __user * __user *arg)
 {
     struct urb *urb = as->urb;
     struct usbdevfs_urb32 __user *userurb = as->userurb;
     void __user *addr = as->userurb;
     unsigned int i;
 
     compute_isochronous_actual_length(urb);
     if (as->userbuffer && urb->actual_length) {
         if (copy_urb_data_to_user(as->userbuffer, urb))
             return -EFAULT;
     }
     if (put_user(as->status, &userurb->status))
         return -EFAULT;
     if (put_user(urb->actual_length, &userurb->actual_length))
         return -EFAULT;
     if (put_user(urb->error_count, &userurb->error_count))
         return -EFAULT;
 
     if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
         for (i = 0; i < urb->number_of_packets; i++) {
             if (put_user(urb->iso_frame_desc[i].actual_length,
                      &userurb->iso_frame_desc[i].actual_length))
                 return -EFAULT;
             if (put_user(urb->iso_frame_desc[i].status,
                      &userurb->iso_frame_desc[i].status))
                 return -EFAULT;
         }
     }
 
     if (put_user(ptr_to_compat(addr), (u32 __user *)arg))
         return -EFAULT;
     return 0;
 }
 
 static int proc_reapurb_compat(struct usb_dev_state *ps, void __user *arg)
 {
     struct async *as = reap_as(ps);
 
     if (as) {
         int retval;
 
         snoop(&ps->dev->dev, "reap %px\n", as->userurb);
         retval = processcompl_compat(as, (void __user * __user *)arg);
         free_async(as);
         return retval;
     }
     if (signal_pending(current))
         return -EINTR;
     return -ENODEV;
 }
 
 static int proc_reapurbnonblock_compat(struct usb_dev_state *ps, void __user *arg)
 {
     int retval;
     struct async *as;
 
     as = async_getcompleted(ps);
     if (as) {
         snoop(&ps->dev->dev, "reap %px\n", as->userurb);
         retval = processcompl_compat(as, (void __user * __user *)arg);
         free_async(as);
     } else {
         retval = (connected(ps) ? -EAGAIN : -ENODEV);
     }
     return retval;
 }
 
 
 #endif
 
 static int proc_disconnectsignal(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_disconnectsignal ds;
 
     if (copy_from_user(&ds, arg, sizeof(ds)))
         return -EFAULT;
     ps->discsignr = ds.signr;
     ps->disccontext.sival_ptr = ds.context;
     return 0;
 }
 
 static int proc_claiminterface(struct usb_dev_state *ps, void __user *arg)
 {
     unsigned int ifnum;
 
     if (get_user(ifnum, (unsigned int __user *)arg))
         return -EFAULT;
     return claimintf(ps, ifnum);
 }
 
 static int proc_releaseinterface(struct usb_dev_state *ps, void __user *arg)
 {
     unsigned int ifnum;
     int ret;
 
     if (get_user(ifnum, (unsigned int __user *)arg))
         return -EFAULT;
     ret = releaseintf(ps, ifnum);
     if (ret < 0)
         return ret;
     destroy_async_on_interface(ps, ifnum);
     return 0;
 }
 
 static int proc_ioctl(struct usb_dev_state *ps, struct usbdevfs_ioctl *ctl)
 {
     int         size;
     void            *buf = NULL;
     int         retval = 0;
     struct usb_interface    *intf = NULL;
     struct usb_driver       *driver = NULL;
 
     if (ps->privileges_dropped)
         return -EACCES;
 
     if (!connected(ps))
         return -ENODEV;
 
     /* alloc buffer */
     size = _IOC_SIZE(ctl->ioctl_code);
     if (size > 0) {
         buf = kmalloc(size, GFP_KERNEL);
         if (buf == NULL)
             return -ENOMEM;
         if ((_IOC_DIR(ctl->ioctl_code) & _IOC_WRITE)) {
             if (copy_from_user(buf, ctl->data, size)) {
                 kfree(buf);
                 return -EFAULT;
             }
         } else {
             memset(buf, 0, size);
         }
     }
 
     if (ps->dev->state != USB_STATE_CONFIGURED)
         retval = -EHOSTUNREACH;
     else if (!(intf = usb_ifnum_to_if(ps->dev, ctl->ifno)))
         retval = -EINVAL;
     else switch (ctl->ioctl_code) {
 
     /* disconnect kernel driver from interface */
     case USBDEVFS_DISCONNECT:
         if (intf->dev.driver) {
             driver = to_usb_driver(intf->dev.driver);
             dev_dbg(&intf->dev, "disconnect by usbfs\n");
             usb_driver_release_interface(driver, intf);
         } else
             retval = -ENODATA;
         break;
 
     /* let kernel drivers try to (re)bind to the interface */
     case USBDEVFS_CONNECT:
         if (!intf->dev.driver)
             retval = device_attach(&intf->dev);
         else
             retval = -EBUSY;
         break;
 
     /* talk directly to the interface's driver */
     default:
         if (intf->dev.driver)
             driver = to_usb_driver(intf->dev.driver);
         if (driver == NULL || driver->unlocked_ioctl == NULL) {
             retval = -ENOTTY;
         } else {
             retval = driver->unlocked_ioctl(intf, ctl->ioctl_code, buf);
             if (retval == -ENOIOCTLCMD)
                 retval = -ENOTTY;
         }
     }
 
     /* cleanup and return */
     if (retval >= 0
             && (_IOC_DIR(ctl->ioctl_code) & _IOC_READ) != 0
             && size > 0
             && copy_to_user(ctl->data, buf, size) != 0)
         retval = -EFAULT;
 
     kfree(buf);
     return retval;
 }
 
 static int proc_ioctl_default(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_ioctl   ctrl;
 
     if (copy_from_user(&ctrl, arg, sizeof(ctrl)))
         return -EFAULT;
     return proc_ioctl(ps, &ctrl);
 }
 
 #ifdef CONFIG_COMPAT
 static int proc_ioctl_compat(struct usb_dev_state *ps, compat_uptr_t arg)
 {
     struct usbdevfs_ioctl32 ioc32;
     struct usbdevfs_ioctl ctrl;
 
     if (copy_from_user(&ioc32, compat_ptr(arg), sizeof(ioc32)))
         return -EFAULT;
     ctrl.ifno = ioc32.ifno;
     ctrl.ioctl_code = ioc32.ioctl_code;
     ctrl.data = compat_ptr(ioc32.data);
     return proc_ioctl(ps, &ctrl);
 }
 #endif
 
 static int proc_claim_port(struct usb_dev_state *ps, void __user *arg)
 {
     unsigned portnum;
     int rc;
 
     if (get_user(portnum, (unsigned __user *) arg))
         return -EFAULT;
     rc = usb_hub_claim_port(ps->dev, portnum, ps);
     if (rc == 0)
         snoop(&ps->dev->dev, "port %d claimed by process %d: %s\n",
             portnum, task_pid_nr(current), current->comm);
     return rc;
 }
 
 static int proc_release_port(struct usb_dev_state *ps, void __user *arg)
 {
     unsigned portnum;
 
     if (get_user(portnum, (unsigned __user *) arg))
         return -EFAULT;
     return usb_hub_release_port(ps->dev, portnum, ps);
 }
 
 static int proc_get_capabilities(struct usb_dev_state *ps, void __user *arg)
 {
     __u32 caps;
 
     caps = USBDEVFS_CAP_ZERO_PACKET | USBDEVFS_CAP_NO_PACKET_SIZE_LIM |
             USBDEVFS_CAP_REAP_AFTER_DISCONNECT | USBDEVFS_CAP_MMAP |
             USBDEVFS_CAP_DROP_PRIVILEGES |
             USBDEVFS_CAP_CONNINFO_EX | MAYBE_CAP_SUSPEND;
     if (!ps->dev->bus->no_stop_on_short)
         caps |= USBDEVFS_CAP_BULK_CONTINUATION;
     if (ps->dev->bus->sg_tablesize)
         caps |= USBDEVFS_CAP_BULK_SCATTER_GATHER;
 
     if (put_user(caps, (__u32 __user *)arg))
         return -EFAULT;
 
     return 0;
 }
 
 static int proc_disconnect_claim(struct usb_dev_state *ps, void __user *arg)
 {
     struct usbdevfs_disconnect_claim dc;
     struct usb_interface *intf;
 
     if (copy_from_user(&dc, arg, sizeof(dc)))
         return -EFAULT;
 
     intf = usb_ifnum_to_if(ps->dev, dc.interface);
     if (!intf)
         return -EINVAL;
 
     if (intf->dev.driver) {
         struct usb_driver *driver = to_usb_driver(intf->dev.driver);
 
         if (ps->privileges_dropped)
             return -EACCES;
 
         if ((dc.flags & USBDEVFS_DISCONNECT_CLAIM_IF_DRIVER) &&
                 strncmp(dc.driver, intf->dev.driver->name,
                     sizeof(dc.driver)) != 0)
             return -EBUSY;
 
         if ((dc.flags & USBDEVFS_DISCONNECT_CLAIM_EXCEPT_DRIVER) &&
                 strncmp(dc.driver, intf->dev.driver->name,
                     sizeof(dc.driver)) == 0)
             return -EBUSY;
 
         dev_dbg(&intf->dev, "disconnect by usbfs\n");
         usb_driver_release_interface(driver, intf);
     }
 
     return claimintf(ps, dc.interface);
 }
 
 static int proc_alloc_streams(struct usb_dev_state *ps, void __user *arg)
 {
     unsigned num_streams, num_eps;
     struct usb_host_endpoint **eps;
     struct usb_interface *intf;
     int r;
 
     r = parse_usbdevfs_streams(ps, arg, &num_streams, &num_eps,
                    &eps, &intf);
     if (r)
         return r;
 
     destroy_async_on_interface(ps,
                    intf->altsetting[0].desc.bInterfaceNumber);
 
     r = usb_alloc_streams(intf, eps, num_eps, num_streams, GFP_KERNEL);
     kfree(eps);
     return r;
 }
 
 static int proc_free_streams(struct usb_dev_state *ps, void __user *arg)
 {
     unsigned num_eps;
     struct usb_host_endpoint **eps;
     struct usb_interface *intf;
     int r;
 
     r = parse_usbdevfs_streams(ps, arg, NULL, &num_eps, &eps, &intf);
     if (r)
         return r;
 
     destroy_async_on_interface(ps,
                    intf->altsetting[0].desc.bInterfaceNumber);
 
     r = usb_free_streams(intf, eps, num_eps, GFP_KERNEL);
     kfree(eps);
     return r;
 }
 
 static int proc_drop_privileges(struct usb_dev_state *ps, void __user *arg)
 {
     u32 data;
 
     if (copy_from_user(&data, arg, sizeof(data)))
         return -EFAULT;
 
     /* This is a one way operation. Once privileges are
      * dropped, you cannot regain them. You may however reissue
      * this ioctl to shrink the allowed interfaces mask.
      */
     ps->interface_allowed_mask &= data;
     ps->privileges_dropped = true;
 
     return 0;
 }
 
 static int proc_forbid_suspend(struct usb_dev_state *ps)
 {
     int ret = 0;
 
     if (ps->suspend_allowed) {
         ret = usb_autoresume_device(ps->dev);
         if (ret == 0)
             ps->suspend_allowed = false;
         else if (ret != -ENODEV)
             ret = -EIO;
     }
     return ret;
 }
 
 static int proc_allow_suspend(struct usb_dev_state *ps)
 {
     if (!connected(ps))
         return -ENODEV;
 
     WRITE_ONCE(ps->not_yet_resumed, 1);
     if (!ps->suspend_allowed) {
         usb_autosuspend_device(ps->dev);
         ps->suspend_allowed = true;
     }
     return 0;
 }
 
 static int proc_wait_for_resume(struct usb_dev_state *ps)
 {
     int ret;
 
     usb_unlock_device(ps->dev);
     ret = wait_event_interruptible(ps->wait_for_resume,
             READ_ONCE(ps->not_yet_resumed) == 0);
     usb_lock_device(ps->dev);
 
     if (ret != 0)
         return -EINTR;
     return proc_forbid_suspend(ps);
 }
 
 /*
  * NOTE:  All requests here that have interface numbers as parameters
  * are assuming that somehow the configuration has been prevented from
  * changing.  But there's no mechanism to ensure that...
  */
 static long usbdev_do_ioctl(struct file *file, unsigned int cmd,
                 void __user *p)
 {
     struct usb_dev_state *ps = file->private_data;
     struct inode *inode = file_inode(file);
     struct usb_device *dev = ps->dev;
     int ret = -ENOTTY;
 
     if (!(file->f_mode & FMODE_WRITE))
         return -EPERM;
 
     usb_lock_device(dev);
 
     /* Reap operations are allowed even after disconnection */
     switch (cmd) {
     case USBDEVFS_REAPURB:
         snoop(&dev->dev, "%s: REAPURB\n", __func__);
         ret = proc_reapurb(ps, p);
         goto done;
 
     case USBDEVFS_REAPURBNDELAY:
         snoop(&dev->dev, "%s: REAPURBNDELAY\n", __func__);
         ret = proc_reapurbnonblock(ps, p);
         goto done;
 
 #ifdef CONFIG_COMPAT
     case USBDEVFS_REAPURB32:
         snoop(&dev->dev, "%s: REAPURB32\n", __func__);
         ret = proc_reapurb_compat(ps, p);
         goto done;
 
     case USBDEVFS_REAPURBNDELAY32:
         snoop(&dev->dev, "%s: REAPURBNDELAY32\n", __func__);
         ret = proc_reapurbnonblock_compat(ps, p);
         goto done;
 #endif
     }
 
     if (!connected(ps)) {
         usb_unlock_device(dev);
         return -ENODEV;
     }
 
     switch (cmd) {
     case USBDEVFS_CONTROL:
         snoop(&dev->dev, "%s: CONTROL\n", __func__);
         ret = proc_control(ps, p);
         if (ret >= 0)
             inode->i_mtime = current_time(inode);
         break;
 
     case USBDEVFS_BULK:
         snoop(&dev->dev, "%s: BULK\n", __func__);
         ret = proc_bulk(ps, p);
         if (ret >= 0)
             inode->i_mtime = current_time(inode);
         break;
 
     case USBDEVFS_RESETEP:
         snoop(&dev->dev, "%s: RESETEP\n", __func__);
         ret = proc_resetep(ps, p);
         if (ret >= 0)
             inode->i_mtime = current_time(inode);
         break;
 
     case USBDEVFS_RESET:
         snoop(&dev->dev, "%s: RESET\n", __func__);
         ret = proc_resetdevice(ps);
         break;
 
     case USBDEVFS_CLEAR_HALT:
         snoop(&dev->dev, "%s: CLEAR_HALT\n", __func__);
         ret = proc_clearhalt(ps, p);
         if (ret >= 0)
             inode->i_mtime = current_time(inode);
         break;
 
     case USBDEVFS_GETDRIVER:
         snoop(&dev->dev, "%s: GETDRIVER\n", __func__);
         ret = proc_getdriver(ps, p);
         break;
 
     case USBDEVFS_CONNECTINFO:
         snoop(&dev->dev, "%s: CONNECTINFO\n", __func__);
         ret = proc_connectinfo(ps, p);
         break;
 
     case USBDEVFS_SETINTERFACE:
         snoop(&dev->dev, "%s: SETINTERFACE\n", __func__);
         ret = proc_setintf(ps, p);
         break;
 
     case USBDEVFS_SETCONFIGURATION:
         snoop(&dev->dev, "%s: SETCONFIGURATION\n", __func__);
         ret = proc_setconfig(ps, p);
         break;
 
     case USBDEVFS_SUBMITURB:
         snoop(&dev->dev, "%s: SUBMITURB\n", __func__);
         ret = proc_submiturb(ps, p);
         if (ret >= 0)
             inode->i_mtime = current_time(inode);
         break;
 
 #ifdef CONFIG_COMPAT
     case USBDEVFS_CONTROL32:
         snoop(&dev->dev, "%s: CONTROL32\n", __func__);
         ret = proc_control_compat(ps, p);
         if (ret >= 0)
             inode->i_mtime = current_time(inode);
         break;
 
     case USBDEVFS_BULK32:
         snoop(&dev->dev, "%s: BULK32\n", __func__);
         ret = proc_bulk_compat(ps, p);
         if (ret >= 0)
             inode->i_mtime = current_time(inode);
         break;
 
     case USBDEVFS_DISCSIGNAL32:
         snoop(&dev->dev, "%s: DISCSIGNAL32\n", __func__);
         ret = proc_disconnectsignal_compat(ps, p);
         break;
 
     case USBDEVFS_SUBMITURB32:
         snoop(&dev->dev, "%s: SUBMITURB32\n", __func__);
         ret = proc_submiturb_compat(ps, p);
         if (ret >= 0)
             inode->i_mtime = current_time(inode);
         break;
 
     case USBDEVFS_IOCTL32:
         snoop(&dev->dev, "%s: IOCTL32\n", __func__);
         ret = proc_ioctl_compat(ps, ptr_to_compat(p));
         break;
 #endif
 
     case USBDEVFS_DISCARDURB:
         snoop(&dev->dev, "%s: DISCARDURB %px\n", __func__, p);
         ret = proc_unlinkurb(ps, p);
         break;
 
     case USBDEVFS_DISCSIGNAL:
         snoop(&dev->dev, "%s: DISCSIGNAL\n", __func__);
         ret = proc_disconnectsignal(ps, p);
         break;
 
     case USBDEVFS_CLAIMINTERFACE:
         snoop(&dev->dev, "%s: CLAIMINTERFACE\n", __func__);
         ret = proc_claiminterface(ps, p);
         break;
 
     case USBDEVFS_RELEASEINTERFACE:
         snoop(&dev->dev, "%s: RELEASEINTERFACE\n", __func__);
         ret = proc_releaseinterface(ps, p);
         break;
 
     case USBDEVFS_IOCTL:
         snoop(&dev->dev, "%s: IOCTL\n", __func__);
         ret = proc_ioctl_default(ps, p);
         break;
 
     case USBDEVFS_CLAIM_PORT:
         snoop(&dev->dev, "%s: CLAIM_PORT\n", __func__);
         ret = proc_claim_port(ps, p);
         break;
 
     case USBDEVFS_RELEASE_PORT:
         snoop(&dev->dev, "%s: RELEASE_PORT\n", __func__);
         ret = proc_release_port(ps, p);
         break;
     case USBDEVFS_GET_CAPABILITIES:
         ret = proc_get_capabilities(ps, p);
         break;
     case USBDEVFS_DISCONNECT_CLAIM:
         ret = proc_disconnect_claim(ps, p);
         break;
     case USBDEVFS_ALLOC_STREAMS:
         ret = proc_alloc_streams(ps, p);
         break;
     case USBDEVFS_FREE_STREAMS:
         ret = proc_free_streams(ps, p);
         break;
     case USBDEVFS_DROP_PRIVILEGES:
         ret = proc_drop_privileges(ps, p);
         break;
     case USBDEVFS_GET_SPEED:
         ret = ps->dev->speed;
         break;
     case USBDEVFS_FORBID_SUSPEND:
         ret = proc_forbid_suspend(ps);
         break;
     case USBDEVFS_ALLOW_SUSPEND:
         ret = proc_allow_suspend(ps);
         break;
     case USBDEVFS_WAIT_FOR_RESUME:
         ret = proc_wait_for_resume(ps);
         break;
     }
 
     /* Handle variable-length commands */
     switch (cmd & ~IOCSIZE_MASK) {
     case USBDEVFS_CONNINFO_EX(0):
         ret = proc_conninfo_ex(ps, p, _IOC_SIZE(cmd));
         break;
     }
 
  done:
     usb_unlock_device(dev);
     if (ret >= 0)
         inode->i_atime = current_time(inode);
     return ret;
 }
 
 static long usbdev_ioctl(struct file *file, unsigned int cmd,
             unsigned long arg)
 {
     int ret;
 
     ret = usbdev_do_ioctl(file, cmd, (void __user *)arg);
 
     return ret;
 }
 
 /* No kernel lock - fine */
 static __poll_t usbdev_poll(struct file *file,
                 struct poll_table_struct *wait)
 {
     struct usb_dev_state *ps = file->private_data;
     __poll_t mask = 0;
 
     poll_wait(file, &ps->wait, wait);
     if (file->f_mode & FMODE_WRITE && !list_empty(&ps->async_completed))
         mask |= EPOLLOUT | EPOLLWRNORM;
     if (!connected(ps))
         mask |= EPOLLHUP;
     if (list_empty(&ps->list))
         mask |= EPOLLERR;
     return mask;
 }
 
 const struct file_operations usbdev_file_operations = {
     .owner =      THIS_MODULE,
     .llseek =     no_seek_end_llseek,
     .read =       usbdev_read,
     .poll =       usbdev_poll,
     .unlocked_ioctl = usbdev_ioctl,
     .compat_ioctl =   compat_ptr_ioctl,
     .mmap =           usbdev_mmap,
     .open =       usbdev_open,
     .release =    usbdev_release,
 };
 
 static void usbdev_remove(struct usb_device *udev)
 {
     struct usb_dev_state *ps;
 
     /* Protect against simultaneous resume */
     mutex_lock(&usbfs_mutex);
     while (!list_empty(&udev->filelist)) {
         ps = list_entry(udev->filelist.next, struct usb_dev_state, list);
         destroy_all_async(ps);
         wake_up_all(&ps->wait);
         WRITE_ONCE(ps->not_yet_resumed, 0);
         wake_up_all(&ps->wait_for_resume);
         list_del_init(&ps->list);
         if (ps->discsignr)
             kill_pid_usb_asyncio(ps->discsignr, EPIPE, ps->disccontext,
                          ps->disc_pid, ps->cred);
     }
     mutex_unlock(&usbfs_mutex);
 }
 
 static int usbdev_notify(struct notifier_block *self,
                    unsigned long action, void *dev)
 {
     switch (action) {
     case USB_DEVICE_ADD:
         break;
     case USB_DEVICE_REMOVE:
         usbdev_remove(dev);
         break;
     }
     return NOTIFY_OK;
 }
 
 static struct notifier_block usbdev_nb = {
     .notifier_call =    usbdev_notify,
 };
 
 static struct cdev usb_device_cdev;
 
 int __init usb_devio_init(void)
 {
     int retval;
 
     retval = register_chrdev_region(USB_DEVICE_DEV, USB_DEVICE_MAX,
                     "usb_device");
     if (retval) {
         printk(KERN_ERR "Unable to register minors for usb_device\n");
         goto out;
     }
     cdev_init(&usb_device_cdev, &usbdev_file_operations);
     retval = cdev_add(&usb_device_cdev, USB_DEVICE_DEV, USB_DEVICE_MAX);
     if (retval) {
         printk(KERN_ERR "Unable to get usb_device major %d\n",
                USB_DEVICE_MAJOR);
         goto error_cdev;
     }
     usb_register_notify(&usbdev_nb);
 out:
     return retval;
 
 error_cdev:
     unregister_chrdev_region(USB_DEVICE_DEV, USB_DEVICE_MAX);
     goto out;
 }
 
 void usb_devio_cleanup(void)
 {
     usb_unregister_notify(&usbdev_nb);
     cdev_del(&usb_device_cdev);
     unregister_chrdev_region(USB_DEVICE_DEV, USB_DEVICE_MAX);
 }