| Message ID | 20190208031313.GA2848@embeddedor (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | fd6d122678054fb10582143de1922e5dab11b1d8 |
| Headers | show |
| Series | [net-next] net: usb: cdc-phonet: use struct_size() in alloc_netdev() | expand |
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Date: Thu, 7 Feb 2019 21:13:13 -0600 > 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> Applied.
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;
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(-)