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Commit 84b0b663 authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Kalle Valo
Browse files

zd1211rw: zd_usb: Use struct_size() helper 



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 usb_int_regs {
	...
        struct reg_data regs[0];
} __packed;

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

So, replace the following function:

static int usb_int_regs_length(unsigned int count)
{
       return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
}

with:

struct_size(regs, regs, count)

This code was detected with the help of Coccinelle.

Signed-off-by: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
parent 82f93cf4

drivers/net/wireless/zydas/zd1211rw/zd_usb.c

+3 −8
Original line number Diff line number Diff line
@@ -1597,11 +1597,6 @@ static int zd_ep_regs_out_msg(struct usb_device *udev, void *data, int len, 
	}

}



static int usb_int_regs_length(unsigned int count)

{

	return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);

}



static void prepare_read_regs_int(struct zd_usb *usb,

				  struct usb_req_read_regs *req,

				  unsigned int count)
@@ -1636,10 +1631,10 @@ static bool check_read_regs(struct zd_usb *usb, struct usb_req_read_regs *req, 
	/* The created block size seems to be larger than expected.

	 * However results appear to be correct.

	 */

	if (rr->length < usb_int_regs_length(count)) {

	if (rr->length < struct_size(regs, regs, count)) {

		dev_dbg_f(zd_usb_dev(usb),

			 "error: actual length %d less than expected %d\n",

			 rr->length, usb_int_regs_length(count));

			 "error: actual length %d less than expected %ld\n",

			 rr->length, struct_size(regs, regs, count));

		return false;

	}