From: Gustavo A. R. Silva Date: Wed, 3 Apr 2019 17:51:10 +0000 (-0700) Subject: Input: evdev - use struct_size() in kzalloc() and vzalloc() X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=ecdf3a965826d8d900a747f0650acb172191dc9b;p=openwrt%2Fstaging%2Fblogic.git Input: evdev - use struct_size() in kzalloc() and vzalloc() 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 = kzalloc(size, 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); Notice that, in this case, variable size is not necessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Dmitry Torokhov --- diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index f48369d6f3a0..ee8dd8b1b09e 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -503,14 +503,13 @@ static int evdev_open(struct inode *inode, struct file *file) { struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev); unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev); - unsigned int size = sizeof(struct evdev_client) + - bufsize * sizeof(struct input_event); struct evdev_client *client; int error; - client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); + client = kzalloc(struct_size(client, buffer, bufsize), + GFP_KERNEL | __GFP_NOWARN); if (!client) - client = vzalloc(size); + client = vzalloc(struct_size(client, buffer, bufsize)); if (!client) return -ENOMEM;