nfp: use struct_size() in kzalloc()
authorGustavo A. R. Silva <gustavo@embeddedor.com>
Thu, 31 Jan 2019 00:38:59 +0000 (18:38 -0600)
committerDavid S. Miller <davem@davemloft.net>
Fri, 1 Feb 2019 23:12:29 +0000 (15:12 -0800)
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>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c

index 802c9224bb32b4de04a92f0114679ba6b0ff99ca..f6f028fa5db907ee8e9e83769851d01b0d62cd07 100644 (file)
@@ -269,8 +269,7 @@ __nfp_eth_read_ports(struct nfp_cpp *cpp, struct nfp_nsp *nsp)
                goto err;
        }
 
-       table = kzalloc(sizeof(*table) +
-                       sizeof(struct nfp_eth_table_port) * cnt, GFP_KERNEL);
+       table = kzalloc(struct_size(table, ports, cnt), GFP_KERNEL);
        if (!table)
                goto err;