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path: root/drivers/usb/core/devio.c
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Diffstat (limited to 'drivers/usb/core/devio.c')
-rw-r--r--drivers/usb/core/devio.c68
1 files changed, 39 insertions, 29 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 218621b9958..a94c63bef63 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -59,6 +59,9 @@
#define USB_DEVICE_MAX USB_MAXBUS * 128
static struct class *usb_device_class;
+/* Mutual exclusion for removal, open, and release */
+DEFINE_MUTEX(usbfs_mutex);
+
struct async {
struct list_head asynclist;
struct dev_state *ps;
@@ -87,9 +90,10 @@ MODULE_PARM_DESC (usbfs_snoop, "true to log all usbfs traffic");
#define MAX_USBFS_BUFFER_SIZE 16384
-static inline int connected (struct usb_device *dev)
+static inline int connected (struct dev_state *ps)
{
- return dev->state != USB_STATE_NOTATTACHED;
+ return (!list_empty(&ps->list) &&
+ ps->dev->state != USB_STATE_NOTATTACHED);
}
static loff_t usbdev_lseek(struct file *file, loff_t offset, int orig)
@@ -118,7 +122,7 @@ static loff_t usbdev_lseek(struct file *file, loff_t offset, int orig)
static ssize_t usbdev_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
{
- struct dev_state *ps = (struct dev_state *)file->private_data;
+ struct dev_state *ps = file->private_data;
struct usb_device *dev = ps->dev;
ssize_t ret = 0;
unsigned len;
@@ -127,7 +131,7 @@ static ssize_t usbdev_read(struct file *file, char __user *buf, size_t nbytes, l
pos = *ppos;
usb_lock_device(dev);
- if (!connected(dev)) {
+ if (!connected(ps)) {
ret = -ENODEV;
goto err;
} else if (pos < 0) {
@@ -301,7 +305,7 @@ static void snoop_urb(struct urb *urb, void __user *userurb)
static void async_completed(struct urb *urb, struct pt_regs *regs)
{
- struct async *as = (struct async *)urb->context;
+ struct async *as = urb->context;
struct dev_state *ps = as->ps;
struct siginfo sinfo;
@@ -541,25 +545,25 @@ static int usbdev_open(struct inode *inode, struct file *file)
struct dev_state *ps;
int ret;
- /*
- * no locking necessary here, as chrdev_open has the kernel lock
- * (still acquire the kernel lock for safety)
- */
+ /* Protect against simultaneous removal or release */
+ mutex_lock(&usbfs_mutex);
+
ret = -ENOMEM;
if (!(ps = kmalloc(sizeof(struct dev_state), GFP_KERNEL)))
- goto out_nolock;
+ goto out;
- lock_kernel();
ret = -ENOENT;
/* check if we are called from a real node or usbfs */
if (imajor(inode) == USB_DEVICE_MAJOR)
dev = usbdev_lookup_minor(iminor(inode));
if (!dev)
- dev = inode->u.generic_ip;
- if (!dev) {
- kfree(ps);
+ dev = inode->i_private;
+ if (!dev)
goto out;
- }
+ ret = usb_autoresume_device(dev, 1);
+ if (ret)
+ goto out;
+
usb_get_dev(dev);
ret = 0;
ps->dev = dev;
@@ -579,30 +583,36 @@ static int usbdev_open(struct inode *inode, struct file *file)
list_add_tail(&ps->list, &dev->filelist);
file->private_data = ps;
out:
- unlock_kernel();
- out_nolock:
- return ret;
+ if (ret)
+ kfree(ps);
+ mutex_unlock(&usbfs_mutex);
+ return ret;
}
static int usbdev_release(struct inode *inode, struct file *file)
{
- struct dev_state *ps = (struct dev_state *)file->private_data;
+ struct dev_state *ps = file->private_data;
struct usb_device *dev = ps->dev;
unsigned int ifnum;
usb_lock_device(dev);
+
+ /* Protect against simultaneous open */
+ 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);
+ usb_autosuspend_device(dev, 1);
usb_unlock_device(dev);
usb_put_dev(dev);
- ps->dev = NULL;
kfree(ps);
- return 0;
+ return 0;
}
static int proc_control(struct dev_state *ps, void __user *arg)
@@ -1322,7 +1332,7 @@ static int proc_ioctl(struct dev_state *ps, struct usbdevfs_ioctl *ctl)
}
}
- if (!connected(ps->dev)) {
+ if (!connected(ps)) {
kfree(buf);
return -ENODEV;
}
@@ -1349,7 +1359,7 @@ static int proc_ioctl(struct dev_state *ps, struct usbdevfs_ioctl *ctl)
/* let kernel drivers try to (re)bind to the interface */
case USBDEVFS_CONNECT:
usb_unlock_device(ps->dev);
- bus_rescan_devices(intf->dev.bus);
+ retval = bus_rescan_devices(intf->dev.bus);
usb_lock_device(ps->dev);
break;
@@ -1413,7 +1423,7 @@ static int proc_ioctl_compat(struct dev_state *ps, compat_uptr_t arg)
*/
static int usbdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
- struct dev_state *ps = (struct dev_state *)file->private_data;
+ struct dev_state *ps = file->private_data;
struct usb_device *dev = ps->dev;
void __user *p = (void __user *)arg;
int ret = -ENOTTY;
@@ -1421,7 +1431,7 @@ static int usbdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd
if (!(file->f_mode & FMODE_WRITE))
return -EPERM;
usb_lock_device(dev);
- if (!connected(dev)) {
+ if (!connected(ps)) {
usb_unlock_device(dev);
return -ENODEV;
}
@@ -1556,18 +1566,18 @@ static int usbdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd
/* No kernel lock - fine */
static unsigned int usbdev_poll(struct file *file, struct poll_table_struct *wait)
{
- struct dev_state *ps = (struct dev_state *)file->private_data;
- unsigned int mask = 0;
+ struct dev_state *ps = file->private_data;
+ unsigned int mask = 0;
poll_wait(file, &ps->wait, wait);
if (file->f_mode & FMODE_WRITE && !list_empty(&ps->async_completed))
mask |= POLLOUT | POLLWRNORM;
- if (!connected(ps->dev))
+ if (!connected(ps))
mask |= POLLERR | POLLHUP;
return mask;
}
-struct file_operations usbfs_device_file_operations = {
+const struct file_operations usbfs_device_file_operations = {
.llseek = usbdev_lseek,
.read = usbdev_read,
.poll = usbdev_poll,
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-21 05:55:54 +0000