Re: [PATCH 1/2] uinput: Support injecting multiple events in one write() call

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Ryan,

On Wed, Sep 11, 2013 at 09:32:52AM +1000, Ryan Mallon wrote:
> Rework the code in uinput_inject_event so that it matches the code in
> evdev_write and allows injecting more than one event, or zero events.
> 
> Signed-off-by: Ryan Mallon <rmallon@gmail.com>
> ---
>  drivers/input/misc/uinput.c |   14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
> index a0a4bba..6aea346 100644
> --- a/drivers/input/misc/uinput.c
> +++ b/drivers/input/misc/uinput.c
> @@ -434,16 +434,20 @@ static ssize_t uinput_inject_event(struct uinput_device *udev,
>  				   const char __user *buffer, size_t count)
>  {
>  	struct input_event ev;
> +	size_t bytes = 0;
>  
> -	if (count < input_event_size())
> +	if (count != 0 && count < input_event_size())
>  		return -EINVAL;
>  
> -	if (input_event_from_user(buffer, &ev))
> -		return -EFAULT;
> +	while (bytes + input_event_size() <= count) {
> +		if (input_event_from_user(buffer + bytes, &ev))
> +			return -EFAULT;

Unless the failure is in the very first packet we should tell the user
how many bytes we have transferred successfully instead of returning
-EFAULT.

Thanks.

-- 
Dmitry