| Message ID | 20190208011052.GA646@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] mpls_iptunnel: use struct_size() helper | expand |
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Date: Thu, 7 Feb 2019 19:10:52 -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 = alloc(sizeof(struct foo) + count * sizeof(struct boo)); > > 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/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c index 94f53a9b7d1a..dda8930f20e7 100644 --- a/net/mpls/mpls_iptunnel.c +++ b/net/mpls/mpls_iptunnel.c @@ -183,8 +183,8 @@ static int mpls_build_state(struct nlattr *nla, &n_labels, NULL, extack)) return -EINVAL; - newts = lwtunnel_state_alloc(sizeof(*tun_encap_info) + - n_labels * sizeof(u32)); + newts = lwtunnel_state_alloc(struct_size(tun_encap_info, label, + n_labels)); if (!newts) 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; struct boo entry[]; }; instance = alloc(sizeof(struct foo) + count * sizeof(struct boo)); 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> --- net/mpls/mpls_iptunnel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)