[RESEND PATCH 2/4] iio: percolate error if event fd fails

[RESEND PATCH 2/4] iio: percolate error if event fd fails

[Linus Walleij]

This makes the error from iio_event_getfd() percolate up
to userspace properly so we can know for sure there is no
events on this device (-ENODEV returned). Before this patch
we would bail out looking for the unsupported evens on the
erroneous (negative) file descriptor.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/iio/industrialio-core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index b3fcc2c449d8..b347524d1b6d 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1153,6 +1153,8 @@ static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 
 	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
 		fd = iio_event_getfd(indio_dev);
+		if (fd < 0)
+			return fd;
 		if (copy_to_user(ip, &fd, sizeof(fd)))
 			return -EFAULT;
 		return 0;
-- 
2.4.3

Re: [RESEND PATCH 2/4] iio: percolate error if event fd fails

[Jonathan Cameron]

On 15/09/15 08:49, Linus Walleij wrote:
> This makes the error from iio_event_getfd() percolate up
> to userspace properly so we can know for sure there is no
> events on this device (-ENODEV returned). Before this patch
> we would bail out looking for the unsupported evens on the
> erroneous (negative) file descriptor.
> 
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Hi Linus,

I applied this one a while back - will be going upstream to Greg shortly.
Got delayed I think by just missing the merge window close.

Jonathan
> ---
>  drivers/iio/industrialio-core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index b3fcc2c449d8..b347524d1b6d 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1153,6 +1153,8 @@ static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  
>  	if (cmd == IIO_GET_EVENT_FD_IOCTL) {
>  		fd = iio_event_getfd(indio_dev);
> +		if (fd < 0)
> +			return fd;
>  		if (copy_to_user(ip, &fd, sizeof(fd)))
>  			return -EFAULT;
>  		return 0;
>