Messages in this thread Patch in this message | | | Date | Mon, 5 Aug 2019 19:06:38 -0500 | From | "Gustavo A. R. Silva" <> | Subject | [PATCH] Input: applespi - use struct_size() helper |
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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(-)
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
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