From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] IB/cm: Use struct_size() in kmalloc() Date: Mon, 7 Jan 2019 11:26:16 -0600 Message-ID: <20190107172616.GA3099@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 = kmalloc(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 = 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/infiniband/core/cm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index edb2cb758be7..af7f74faa448 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -4052,8 +4052,7 @@ static void cm_recv_handler(struct ib_mad_agent *mad_agent, atomic_long_inc(&port->counter_group[CM_RECV]. counter[attr_id - CM_ATTR_ID_OFFSET]); - work = kmalloc(sizeof(*work) + sizeof(struct sa_path_rec) * paths, - GFP_KERNEL); + work = kmalloc(struct_size(work, path, paths), GFP_KERNEL); if (!work) { ib_free_recv_mad(mad_recv_wc); return; -- 2.20.1