From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] eeprom: at24: use struct_size() in devm_kzalloc() Date: Wed, 29 May 2019 11:30:52 -0500 Message-ID: <20190529163052.GA29158@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: Bartosz Golaszewski , Arnd Bergmann , Greg Kroah-Hartman Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-Id: linux-i2c@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; struct boo entry[]; }; size = sizeof(struct foo) + count * sizeof(struct boo); instance = devm_kzalloc(dev, size, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL); Notice that, in this case, variable at24_size is not necessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/misc/eeprom/at24.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index ba8e73812644..78ba6b1917a8 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -568,7 +568,6 @@ static int at24_probe(struct i2c_client *client) unsigned int i, num_addresses; struct at24_data *at24; struct regmap *regmap; - size_t at24_size; bool writable; u8 test_byte; int err; @@ -652,8 +651,8 @@ static int at24_probe(struct i2c_client *client) if (IS_ERR(regmap)) return PTR_ERR(regmap); - at24_size = sizeof(*at24) + num_addresses * sizeof(struct at24_client); - at24 = devm_kzalloc(dev, at24_size, GFP_KERNEL); + at24 = devm_kzalloc(dev, struct_size(at24, client, num_addresses), + GFP_KERNEL); if (!at24) return -ENOMEM; -- 2.21.0