diff options
Diffstat (limited to 'drivers/input/misc/uinput.c')
| -rw-r--r-- | drivers/input/misc/uinput.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c index 736056897e50..1b4ee4a5c49c 100644 --- a/drivers/input/misc/uinput.c +++ b/drivers/input/misc/uinput.c @@ -452,9 +452,28 @@ static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t return retval; } +static bool uinput_fetch_next_event(struct uinput_device *udev, + struct input_event *event) +{ + bool have_event; + + spin_lock_irq(&udev->dev->event_lock); + + have_event = udev->head != udev->tail; + if (have_event) { + *event = udev->buff[udev->tail]; + udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE; + } + + spin_unlock_irq(&udev->dev->event_lock); + + return have_event; +} + static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) { struct uinput_device *udev = file->private_data; + struct input_event event; int retval = 0; if (udev->state != UIST_CREATED) @@ -477,12 +496,14 @@ static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, goto out; } - while (udev->head != udev->tail && retval + input_event_size() <= count) { - if (input_event_to_user(buffer + retval, &udev->buff[udev->tail])) { + while (retval + input_event_size() <= count && + uinput_fetch_next_event(udev, &event)) { + + if (input_event_to_user(buffer + retval, &event)) { retval = -EFAULT; goto out; } - udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE; + retval += input_event_size(); } |