From 5ebf5c890324ffa5eaca579dac6913f3e29a28e3 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 18 Feb 2019 13:06:41 -0600 Subject: usb: core: config: Use struct_size() in kzalloc() 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 len 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: Greg Kroah-Hartman --- drivers/usb/core/config.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/usb/core/config.c') diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 7bb6b1bd06c8..20ff036b4c22 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -552,7 +552,7 @@ static int usb_parse_configuration(struct usb_device *dev, int cfgidx, unsigned char *buffer2; int size2; struct usb_descriptor_header *header; - int len, retval; + int retval; u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES]; unsigned iad_num = 0; @@ -707,8 +707,8 @@ static int usb_parse_configuration(struct usb_device *dev, int cfgidx, nalts[i] = j = USB_MAXALTSETTING; } - len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j; - config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL); + intfc = kzalloc(struct_size(intfc, altsetting, j), GFP_KERNEL); + config->intf_cache[i] = intfc; if (!intfc) return -ENOMEM; kref_init(&intfc->ref); -- cgit v1.2.3-59-g8ed1b