HID: hiddev cleanup -- handle all error conditions properly
This is a cleanup of hiddev and fixes the following issues: - thread safety by locking in read & ioctl, introducing a per device mutex - race between ioctl and disconnect, introducing a flag and locking in form of a per low level device mutex - race between open and other methods, making sure only successfully opened devices are put on the list, changing order of events - range checking both upper and lower limits of the minor range - make sure further calls to open fail for unplugged devices even if the device still has opened files - error checking for low level open - possible loss of wakeup events, using standard waiting macros - race in initialisation by moving registration after full initialisation Signed-off-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Oliver Neukum
Jiri Kosina
parent
42859e0bd2
commit
079034073f
1 changed files with 99 additions and 36 deletions
|
|
@ -49,6 +49,7 @@
|
|||
struct hiddev {
|
||||
int exist;
|
||||
int open;
|
||||
struct mutex existancelock;
|
||||
wait_queue_head_t wait;
|
||||
struct hid_device *hid;
|
||||
struct list_head list;
|
||||
|
|
@ -63,6 +64,7 @@ struct hiddev_list {
|
|||
struct fasync_struct *fasync;
|
||||
struct hiddev *hiddev;
|
||||
struct list_head node;
|
||||
struct mutex thread_lock;
|
||||
};
|
||||
|
||||
static struct hiddev *hiddev_table[HIDDEV_MINORS];
|
||||
|
|
@ -264,29 +266,48 @@ static int hiddev_release(struct inode * inode, struct file * file)
|
|||
static int hiddev_open(struct inode *inode, struct file *file)
|
||||
{
|
||||
struct hiddev_list *list;
|
||||
unsigned long flags;
|
||||
int res;
|
||||
|
||||
int i = iminor(inode) - HIDDEV_MINOR_BASE;
|
||||
|
||||
if (i >= HIDDEV_MINORS || !hiddev_table[i])
|
||||
if (i >= HIDDEV_MINORS || i < 0 || !hiddev_table[i])
|
||||
return -ENODEV;
|
||||
|
||||
if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
|
||||
return -ENOMEM;
|
||||
mutex_init(&list->thread_lock);
|
||||
|
||||
list->hiddev = hiddev_table[i];
|
||||
|
||||
spin_lock_irqsave(&list->hiddev->list_lock, flags);
|
||||
list_add_tail(&list->node, &hiddev_table[i]->list);
|
||||
spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
|
||||
|
||||
file->private_data = list;
|
||||
|
||||
if (!list->hiddev->open++)
|
||||
if (list->hiddev->exist)
|
||||
usbhid_open(hiddev_table[i]->hid);
|
||||
/*
|
||||
* no need for locking because the USB major number
|
||||
* is shared which usbcore guards against disconnect
|
||||
*/
|
||||
if (list->hiddev->exist) {
|
||||
if (!list->hiddev->open++) {
|
||||
res = usbhid_open(hiddev_table[i]->hid);
|
||||
if (res < 0) {
|
||||
res = -EIO;
|
||||
goto bail;
|
||||
}
|
||||
}
|
||||
} else {
|
||||
res = -ENODEV;
|
||||
goto bail;
|
||||
}
|
||||
|
||||
spin_lock_irq(&list->hiddev->list_lock);
|
||||
list_add_tail(&list->node, &hiddev_table[i]->list);
|
||||
spin_unlock_irq(&list->hiddev->list_lock);
|
||||
|
||||
return 0;
|
||||
bail:
|
||||
file->private_data = NULL;
|
||||
kfree(list->hiddev);
|
||||
return res;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -305,7 +326,7 @@ static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t coun
|
|||
DECLARE_WAITQUEUE(wait, current);
|
||||
struct hiddev_list *list = file->private_data;
|
||||
int event_size;
|
||||
int retval = 0;
|
||||
int retval;
|
||||
|
||||
event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
|
||||
sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
|
||||
|
|
@ -313,10 +334,14 @@ static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t coun
|
|||
if (count < event_size)
|
||||
return 0;
|
||||
|
||||
/* lock against other threads */
|
||||
retval = mutex_lock_interruptible(&list->thread_lock);
|
||||
if (retval)
|
||||
return -ERESTARTSYS;
|
||||
|
||||
while (retval == 0) {
|
||||
if (list->head == list->tail) {
|
||||
add_wait_queue(&list->hiddev->wait, &wait);
|
||||
set_current_state(TASK_INTERRUPTIBLE);
|
||||
prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
|
||||
|
||||
while (list->head == list->tail) {
|
||||
if (file->f_flags & O_NONBLOCK) {
|
||||
|
|
@ -332,35 +357,45 @@ static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t coun
|
|||
break;
|
||||
}
|
||||
|
||||
/* let O_NONBLOCK tasks run */
|
||||
mutex_unlock(&list->thread_lock);
|
||||
schedule();
|
||||
if (mutex_lock_interruptible(&list->thread_lock))
|
||||
return -EINTR;
|
||||
set_current_state(TASK_INTERRUPTIBLE);
|
||||
}
|
||||
finish_wait(&list->hiddev->wait, &wait);
|
||||
|
||||
set_current_state(TASK_RUNNING);
|
||||
remove_wait_queue(&list->hiddev->wait, &wait);
|
||||
}
|
||||
|
||||
if (retval)
|
||||
if (retval) {
|
||||
mutex_unlock(&list->thread_lock);
|
||||
return retval;
|
||||
}
|
||||
|
||||
|
||||
while (list->head != list->tail &&
|
||||
retval + event_size <= count) {
|
||||
if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
|
||||
if (list->buffer[list->tail].field_index !=
|
||||
HID_FIELD_INDEX_NONE) {
|
||||
if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
|
||||
struct hiddev_event event;
|
||||
|
||||
event.hid = list->buffer[list->tail].usage_code;
|
||||
event.value = list->buffer[list->tail].value;
|
||||
if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
|
||||
if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
|
||||
mutex_unlock(&list->thread_lock);
|
||||
return -EFAULT;
|
||||
}
|
||||
retval += sizeof(struct hiddev_event);
|
||||
}
|
||||
} else {
|
||||
if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
|
||||
(list->flags & HIDDEV_FLAG_REPORT) != 0) {
|
||||
if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
|
||||
|
||||
if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
|
||||
mutex_unlock(&list->thread_lock);
|
||||
return -EFAULT;
|
||||
}
|
||||
retval += sizeof(struct hiddev_usage_ref);
|
||||
}
|
||||
}
|
||||
|
|
@ -368,6 +403,7 @@ static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t coun
|
|||
}
|
||||
|
||||
}
|
||||
mutex_unlock(&list->thread_lock);
|
||||
|
||||
return retval;
|
||||
}
|
||||
|
|
@ -555,7 +591,7 @@ static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|||
struct hid_field *field;
|
||||
struct usbhid_device *usbhid = hid->driver_data;
|
||||
void __user *user_arg = (void __user *)arg;
|
||||
int i;
|
||||
int i, r;
|
||||
|
||||
/* Called without BKL by compat methods so no BKL taken */
|
||||
|
||||
|
|
@ -619,10 +655,22 @@ static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|||
}
|
||||
|
||||
case HIDIOCGSTRING:
|
||||
return hiddev_ioctl_string(hiddev, cmd, user_arg);
|
||||
mutex_lock(&hiddev->existancelock);
|
||||
if (!hiddev->exist)
|
||||
r = hiddev_ioctl_string(hiddev, cmd, user_arg);
|
||||
else
|
||||
r = -ENODEV;
|
||||
mutex_unlock(&hiddev->existancelock);
|
||||
return r;
|
||||
|
||||
case HIDIOCINITREPORT:
|
||||
mutex_lock(&hiddev->existancelock);
|
||||
if (!hiddev->exist) {
|
||||
mutex_unlock(&hiddev->existancelock);
|
||||
return -ENODEV;
|
||||
}
|
||||
usbhid_init_reports(hid);
|
||||
mutex_unlock(&hiddev->existancelock);
|
||||
|
||||
return 0;
|
||||
|
||||
|
|
@ -636,8 +684,12 @@ static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|||
if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
|
||||
return -EINVAL;
|
||||
|
||||
usbhid_submit_report(hid, report, USB_DIR_IN);
|
||||
usbhid_wait_io(hid);
|
||||
mutex_lock(&hiddev->existancelock);
|
||||
if (hiddev->exist) {
|
||||
usbhid_submit_report(hid, report, USB_DIR_IN);
|
||||
usbhid_wait_io(hid);
|
||||
}
|
||||
mutex_unlock(&hiddev->existancelock);
|
||||
|
||||
return 0;
|
||||
|
||||
|
|
@ -651,8 +703,12 @@ static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|||
if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
|
||||
return -EINVAL;
|
||||
|
||||
usbhid_submit_report(hid, report, USB_DIR_OUT);
|
||||
usbhid_wait_io(hid);
|
||||
mutex_lock(&hiddev->existancelock);
|
||||
if (hiddev->exist) {
|
||||
usbhid_submit_report(hid, report, USB_DIR_OUT);
|
||||
usbhid_wait_io(hid);
|
||||
}
|
||||
mutex_unlock(&hiddev->existancelock);
|
||||
|
||||
return 0;
|
||||
|
||||
|
|
@ -710,7 +766,13 @@ static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|||
case HIDIOCGUSAGES:
|
||||
case HIDIOCSUSAGES:
|
||||
case HIDIOCGCOLLECTIONINDEX:
|
||||
return hiddev_ioctl_usage(hiddev, cmd, user_arg);
|
||||
mutex_lock(&hiddev->existancelock);
|
||||
if (hiddev->exist)
|
||||
r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
|
||||
else
|
||||
r = -ENODEV;
|
||||
mutex_unlock(&hiddev->existancelock);
|
||||
return r;
|
||||
|
||||
case HIDIOCGCOLLECTIONINFO:
|
||||
if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
|
||||
|
|
@ -808,24 +870,23 @@ int hiddev_connect(struct hid_device *hid, unsigned int force)
|
|||
if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
|
||||
return -1;
|
||||
|
||||
init_waitqueue_head(&hiddev->wait);
|
||||
INIT_LIST_HEAD(&hiddev->list);
|
||||
spin_lock_init(&hiddev->list_lock);
|
||||
mutex_init(&hiddev->existancelock);
|
||||
hiddev->hid = hid;
|
||||
hiddev->exist = 1;
|
||||
|
||||
retval = usb_register_dev(usbhid->intf, &hiddev_class);
|
||||
if (retval) {
|
||||
err_hid("Not able to get a minor for this device.");
|
||||
kfree(hiddev);
|
||||
return -1;
|
||||
} else {
|
||||
hid->minor = usbhid->intf->minor;
|
||||
hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
|
||||
}
|
||||
|
||||
init_waitqueue_head(&hiddev->wait);
|
||||
INIT_LIST_HEAD(&hiddev->list);
|
||||
spin_lock_init(&hiddev->list_lock);
|
||||
hiddev->hid = hid;
|
||||
hiddev->exist = 1;
|
||||
|
||||
hid->minor = usbhid->intf->minor;
|
||||
hid->hiddev = hiddev;
|
||||
|
||||
hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
@ -839,7 +900,9 @@ void hiddev_disconnect(struct hid_device *hid)
|
|||
struct hiddev *hiddev = hid->hiddev;
|
||||
struct usbhid_device *usbhid = hid->driver_data;
|
||||
|
||||
mutex_lock(&hiddev->existancelock);
|
||||
hiddev->exist = 0;
|
||||
mutex_unlock(&hiddev->existancelock);
|
||||
|
||||
hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
|
||||
usb_deregister_dev(usbhid->intf, &hiddev_class);
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue