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

From: Dmitry Torokhov
Date: Tue Sep 10 2013 - 20:14:36 EST


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@xxxxxxxxx>
> ---
> 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
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