From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] IB/core: Use struct_size() in kzalloc() Date: Fri, 4 Jan 2019 12:15:58 -0600 Message-ID: <20190104181558.GA2403@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: Doug Ledford , Jason Gunthorpe Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-Id: linux-rdma@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/infiniband/core/sa_query.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c index 97e6d7b69abf..7925e45ea88a 100644 --- a/drivers/infiniband/core/sa_query.c +++ b/drivers/infiniband/core/sa_query.c @@ -2342,9 +2342,7 @@ static void ib_sa_add_one(struct ib_device *device) s = rdma_start_port(device); e = rdma_end_port(device); - sa_dev = kzalloc(sizeof *sa_dev + - (e - s + 1) * sizeof (struct ib_sa_port), - GFP_KERNEL); + sa_dev = kzalloc(struct_size(sa_dev, port, e - s + 1), GFP_KERNEL); if (!sa_dev) return; -- 2.20.1