From 37ad2e343449ced9e41505eae5494bf40f433181 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 6 Aug 2019 09:03:16 -0700 Subject: [PATCH] Input: applespi - use struct_size() helper 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 Signed-off-by: Dmitry Torokhov --- 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 acf34a5..584289b 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, -- 2.7.4