| Message ID | 20190115195006.GA11327@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] net, decnet: use struct_size() in kzalloc() | expand |
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Date: Tue, 15 Jan 2019 13:50:06 -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; > struct boo entry[]; > }; > > instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), 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); > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Applied, thanks.
diff --git a/net/decnet/dn_fib.c b/net/decnet/dn_fib.c index f78fe58eafc8..6cd3737593a6 100644 --- a/net/decnet/dn_fib.c +++ b/net/decnet/dn_fib.c @@ -282,7 +282,7 @@ struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct nlattr *att (nhs = dn_fib_count_nhs(attrs[RTA_MULTIPATH])) == 0) goto err_inval; - fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct dn_fib_nh), GFP_KERNEL); + fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL); err = -ENOBUFS; if (fi == NULL) goto failure;
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[]; }; instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), 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); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- net/decnet/dn_fib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)