Message ID | 20190218185937.GA16947@embeddedor (mailing list archive) |
---|---|
State | Mainlined |
Commit | eeca7606dd6e2445f505903f235e908eb7b78dfc |
Headers | show |
Series | usb: dwc2: use struct_size() in kzalloc() | expand |
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index dd82fa516f3f..3f087962f498 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -3981,10 +3981,8 @@ static struct dwc2_hcd_urb *dwc2_hcd_urb_alloc(struct dwc2_hsotg *hsotg, gfp_t mem_flags) { struct dwc2_hcd_urb *urb; - u32 size = sizeof(*urb) + iso_desc_count * - sizeof(struct dwc2_hcd_iso_packet_desc); - urb = kzalloc(size, mem_flags); + urb = kzalloc(struct_size(urb, iso_descs, iso_desc_count), mem_flags); if (urb) urb->packet_count = iso_desc_count; return urb;
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 <gustavo@embeddedor.com> --- drivers/usb/dwc2/hcd.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)