From 6756f4c375db11af7039985636bddde676615a94 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 8 Jan 2019 09:22:25 -0600 Subject: USB: core: urb: Use struct_size() in kmalloc() 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/urb.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/usb/core') diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index f51750bcd152..0eab79f82ce4 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -70,9 +70,8 @@ struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) { struct urb *urb; - urb = kmalloc(sizeof(struct urb) + - iso_packets * sizeof(struct usb_iso_packet_descriptor), - mem_flags); + urb = kmalloc(struct_size(urb, iso_frame_desc, iso_packets), + mem_flags); if (!urb) return NULL; usb_init_urb(urb); -- cgit