| Message ID | 20190806000638.GA4827@embeddedor (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 37ad2e343449ced9e41505eae5494bf40f433181 |
| Headers | show |
| Series | Input: applespi - use struct_size() helper | expand |
On Mon, Aug 05, 2019 at 07:06:38PM -0500, Gustavo A. R. Silva wrote: > One of the more common cases of allocation size calculations is finding > the size of a structure that has a zero-sized array at the end, along > with memory for some number of elements for that array. For example: > > struct touchpad_protocol { > ... > struct tp_finger fingers[0]; > }; > > Make use of the struct_size() helper instead of an open-coded version > in order to avoid any potential type mistakes. > > So, replace the following form: > > sizeof(*tp) + tp->number_of_fingers * sizeof(tp->fingers[0]); > > with: > > struct_size(tp, fingers, tp->number_of_fingers) > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Applied, thank you. > --- > drivers/input/keyboard/applespi.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/input/keyboard/applespi.c b/drivers/input/keyboard/applespi.c > index acf34a5ff571..584289b67fb3 100644 > --- a/drivers/input/keyboard/applespi.c > +++ b/drivers/input/keyboard/applespi.c > @@ -1494,8 +1494,7 @@ static void applespi_got_data(struct applespi_data *applespi) > size_t tp_len; > > tp = &message->touchpad; > - tp_len = sizeof(*tp) + > - tp->number_of_fingers * sizeof(tp->fingers[0]); > + tp_len = struct_size(tp, fingers, tp->number_of_fingers); > > if (le16_to_cpu(message->length) + 2 != tp_len) { > dev_warn_ratelimited(&applespi->spi->dev, > -- > 2.22.0 >
diff --git a/drivers/input/keyboard/applespi.c b/drivers/input/keyboard/applespi.c index acf34a5ff571..584289b67fb3 100644 --- a/drivers/input/keyboard/applespi.c +++ b/drivers/input/keyboard/applespi.c @@ -1494,8 +1494,7 @@ static void applespi_got_data(struct applespi_data *applespi) size_t tp_len; tp = &message->touchpad; - tp_len = sizeof(*tp) + - tp->number_of_fingers * sizeof(tp->fingers[0]); + tp_len = struct_size(tp, fingers, tp->number_of_fingers); if (le16_to_cpu(message->length) + 2 != tp_len) { dev_warn_ratelimited(&applespi->spi->dev,
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct touchpad_protocol { ... struct tp_finger fingers[0]; }; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. So, replace the following form: sizeof(*tp) + tp->number_of_fingers * sizeof(tp->fingers[0]); with: struct_size(tp, fingers, tp->number_of_fingers) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/input/keyboard/applespi.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)