From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] md: raid10: Use struct_size() in kmalloc() Date: Tue, 4 Jun 2019 17:44:18 -0500 Message-ID: <20190604224418.GA23187@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: Shaohua Li Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-Id: linux-raid.ids 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[]; }; instance = kmalloc(size, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/md/raid10.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index aea11476fee6..3caafd433163 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -4780,8 +4780,7 @@ static int handle_reshape_read_error(struct mddev *mddev, int idx = 0; struct page **pages; - r10b = kmalloc(sizeof(*r10b) + - sizeof(struct r10dev) * conf->copies, GFP_NOIO); + r10b = kmalloc(struct_size(r10b, devs, conf->copies), GFP_NOIO); if (!r10b) { set_bit(MD_RECOVERY_INTR, &mddev->recovery); return -ENOMEM; -- 2.21.0