From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] Input: tca6416-keypad: use struct_size() in kzalloc() Date: Tue, 8 Jan 2019 09:28:16 -0600 Message-ID: <20190108152816.GA7486@embeddedor> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Torokhov Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-Id: linux-input@vger.kernel.org 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 foo { int stuff; void *entry[]; }; instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/input/keyboard/tca6416-keypad.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c index dc983ab6c0ad..cdeef180aead 100644 --- a/drivers/input/keyboard/tca6416-keypad.c +++ b/drivers/input/keyboard/tca6416-keypad.c @@ -219,9 +219,7 @@ static int tca6416_keypad_probe(struct i2c_client *client, return -EINVAL; } - chip = kzalloc(sizeof(struct tca6416_keypad_chip) + - pdata->nbuttons * sizeof(struct tca6416_button), - GFP_KERNEL); + chip = kzalloc(struct_size(chip, buttons, pdata->nbuttons), GFP_KERNEL); input = input_allocate_device(); if (!chip || !input) { error = -ENOMEM; -- 2.20.1