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[];
};
size = sizeof(struct foo) + count * sizeof(struct boo);
instance = alloc(size, GFP_KERNEL)
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
size = struct_size(instance, entry, count);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
net/bridge/br_multicast.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 1fb885a33c66..4a048fd1cbea 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1018,8 +1018,7 @@ static int br_ip6_multicast_mld2_report(struct net_bridge *br,
if (!nsrcs)
return -EINVAL;
- grec_len = sizeof(*grec) +
- sizeof(struct in6_addr) * ntohs(*nsrcs);
+ grec_len = struct_size(grec, grec_src, ntohs(*nsrcs));
if (!ipv6_mc_may_pull(skb, len + grec_len))
return -EINVAL;
--
2.20.1
