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Subject[PATCH net-next] net: usb: cdc-phonet: use struct_size() in alloc_netdev()
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 = alloc(sizeof(struct foo) + count * sizeof(void *));

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = alloc(struct_size(instance, entry, count));

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/net/usb/cdc-phonet.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/cdc-phonet.c b/drivers/net/usb/cdc-phonet.c
index 78b16eb9e58c..63aaae487995 100644
--- a/drivers/net/usb/cdc-phonet.c
+++ b/drivers/net/usb/cdc-phonet.c
@@ -361,8 +361,8 @@ static int usbpn_probe(struct usb_interface *intf, const struct usb_device_id *i
else
return -EINVAL;

- dev = alloc_netdev(sizeof(*pnd) + sizeof(pnd->urbs[0]) * rxq_size,
- ifname, NET_NAME_UNKNOWN, usbpn_setup);
+ dev = alloc_netdev(struct_size(pnd, urbs, rxq_size), ifname,
+ NET_NAME_UNKNOWN, usbpn_setup);
if (!dev)
return -ENOMEM;

--
2.20.1
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